Wireless Standards Comparison Table

Common WiFi Connectors

These are some common connectors and pigtails used in the Wireless world. The pictures should help when choosing pigtails to connect a wireless card to an antenna. There are other connectors as well, so hopefully the page will grow to be a definitive guide.

U.fl (Hirose)

The U.fl connector comes on most MiniPCI cards such as the senao NL-2511MP(prism 2.5 chipset), Senao NL-3054MP(PrismGT chipset), Intel ProWireless, Cisco, Toshiba etc. ( Also known as AMC)

MC CARD (Lucent) to N-Male Pigtail

The Lucent connector comes on cards such as the Orinoco PCMCIA. It has a bad reputation as being easily broken. Connects to a antennas that have an N-Female such as the WaveGuide, Yagi, Cantenna and bigger Omni antennas.

U.fl to N Female Bulkhead Pigtail

The U.fl connector comes on most MiniPCI cards such as the senao NL-2511MP(prism 2.5 chipset), Senao NL-3054MP(PrismGT chipset), Intel ProWireless, Cisco, Toshiba etc. When setting up a WRAP, this pigtail can go on the MiniPCI and the N Female Bulkhead is installed in the case.

RP SMA Male to N Female Pigtail

The RP-SMA is commonly used on PCI cards and access points/routers that have a removeable antenna. Brands such as Netgear and D-Link have these. Hills Parabolic Dish antennas come with a short length of coax and a N-Male connector, so this pigtail can go between an AP and Hills.

MC Card (Lucent) Connector

Commonly found on PCMCIA cards such as D-Link, Orinoco and Lucent based cards

N Male Connector

Hills Parabolic Dish antennas, among others, come with a short length of coax and a N-Male connector. Connects to alot of anennas that have an N-Female such as the Yagi, Cantenna and bigger Omni antennas.

RP SMA Female Connector

The RP-SMA Female is commonly used on PCI cards and access points/routers that have a removeable antenna. Brands such as Netgear and D-Link have these.

RP SMA Male Connector

The RP-SMA Male is commonly used on Antennas that go onto PCI cards and access points/routers that have a removeable antenna. Brands such as Netgear and D-Link have these.

SMA Female Connector

Normal SMA is not commonly used on wireless gear

RP SMA Female PCB Jack

The RP SMA Female Straight PCB Jack is commonly used on access points/routers and wireless cards that use a removeable antenna. Brands such as Netgear, Mitsubishi, Edimax/UltraWAP,Minitar, and D-Link have these. It is available in a variety of configurations such as straight, right-angled, long straight and edge mount.

ACK Timeouts and the effects on distance links

All 802.11 a/b/g wireless devices use a number of time constants, defined by the IEEE specifications, to sense other carriers using the wireless media and avoid collisions (compared to 802.3 which only senses collisions) as well as for retransmission of lost frames. The important constants to consider are Slottime, CTS timeout and ACK timeout. Slottime is more important for collision avoidance when multiple stations are connected, or when one is trying to simulate full duplex communication, while ACK timeouts are more important for point to point communication. Other constants that may restrain the maximum link distance are SIFS (Short Inter Frame Spacing), DIFS (Distributed IFS) and PIFS (Point Coordination IFS.) DIFS is the amount of time a station must sense a clear radio before beginning a new transmission sequence. SIFS is the amount of time a station must wait before sending or beginning to receive a RTS, CTS or ACK frame. PIFS is the DIFS for the access point in a special access method known as Point Coordination Function. The times are defined such that the RTS, CTS and ACK frames are given a higher priority (ie once a packet transmission sequence has begun, the station holds onto the channel until it is finished)

In 802.11b, the constants are mandated by IEEE as follows:

• Slottime = 20 µs
• SIFS = 10 µs
• PIFS = SIFS + Slottime = 30 µs
• DIFS = SIFS + 2 x Slottime = 50 µs

In 802.11g:

• Slottime = 9 µs
• SIFS = 10 µs
• DIFS = SIFS + 2 x Slottime = 28 µs

In 802.11a:

• Slottime = 9 µs
• SIFS = 16 µs
• DIFS = SIFS + 2 x Slottime = 34 µs

Note: DIFS/SIFS/PIFS are used for physical layer carrier sensing while the MAC layer performs the collision detection using CTS and ACK timeouts. Default CTS and ACK timeouts vary between manufacturers.

Normal Transmission flow without RTS/CTS handshaking

Sender: Wait DIFS, Send Data, Wait SIFS, Listen for and receive ACK (until maximum ACK timeout), Repeat

Receiver: Listen for and receive Data,Wait SIFS, Send ACK, Wait DIFS

Distance Limitations in 802.11b

Optimum ACK Timeout, Slottime and DIFS all depend on Air Propagation Time in some way. The IEEE standard defines Air Propagation Time as 1 µs ±(10% SIFS.) Radio waves propagate at approximately 300 meters per µs. 

    ACK Timeout: Clearly if the ACK timeout is shorter than the time it takes for the end of the last data packet (+ SIFS) to propagate to the receiver + the start of the ACK for that packet to propagate back to the sender, then the sending MAC will assume that the packet has been lost and will unnecessarily retransmit the data packet. The retransmitted packet will end up colliding with the ACK that is on its way back, inducing the back-off part of the protocol thus reducing throughput. If, conversely, the ACK timeout is set too long, the transmitter waits unncesessarily long before retransmitting any lost frames and thus reduces the throughput of the link (more important as the bit error of the environment increases.) Similar conclusions can be drawn about the CTS timeout, however RTS/CTS is only for reducing collisions with hidden nodes and can be turned off in the majority of cases. Most implementations assume the IEEE recommended one-way Air Propagation Time of 1 µs, thus tune the ACK Timeout of their devices to 300 meters. This is the maximum distance that high throughput can be achieved between a local network of IEEE 802.11b compliant devices out of the box. The links will still work over longer distances, but throughput will drop as the distance increases.

    Example: With radio waves propagating at an approximate speed of 300 meters per microsecond, a 3000 m link would require an Air Propagation Time of 10 µs (9 µs more than usual.) The ACK Timeout must account for a round trip propagation, therefore for a 3000 m link to achieve maximum throughput, another 18 µs must be added to a standard ACK Timeout. This maximum throughput will be slightly less than can be achieved at close range, but will be much more than if the ACK Timeout is not changed.

    Slottime: A station is only allowed to transmit at the beginning of the slottime, so this time should not end before the signal reaches the destination. This gives a maximum distance of 20  µs x 300 m / µs = 6000 meters. Assuming that the ACK timeouts have been increased accordingly, this is the maximum distance between any station in a point-to-multipoint environment (assuming no hidden stations) without incurring heavy exponential backoff.

    DIFS: A station must wait DIFS before initiating a new transfer, in other words, for 802.11b, the stations have 50 µs to sense the channel to avoid collision with a frame sent from the furthest node. This means the maximum distance that the furthest node can be is 300 m / µs x 50 µs = 15000 meters. Assuming that the ACK timeouts have been increased accordingly, this is the maximum point-to-point distance before throughput drops dramatically without the slottime (DIFS is based on slottime) being changed.

Long distance links in 802.11g/a

The principles are the same, but the numbers are different. The default timings are much more strict, so for any reasonable distance link the ACK timeout and Slottime will probably need to be changed, even for point-to-point links. Many Ethernet bridge/gateway devices provide little or no way to change this, however certain miniPCI adapters such as the CM9, Senao and SuperRange cards have driver support in BSD and Linux to alter these settings. The possible throughput that can be achieved when properly tweaked, though not full theoretical rate, is much higher than 802.11b can achieve over the same distance and is worth the effort.

Changing ACK timeout and Slottime

For every further 300 meter increase in distance above 300 meters add 1 µs to the Slottime of your device, and 2 µs to the ACK timeout and CTS timeout.

Every station connected on the same channel should have the same time constants.

Use the furthest distance between any two nodes as the distance in your calculations.

For specific examples for popular operating systems and drivers please see http://www.air-stream.org/Change_ACK

Definitions

ACK Timeout = Air Propagation Time (max) + SIFS + Time to transmit 14 byte ACK frame [14 * 8 / bitrate in Mbps] + Air Propagation Time (max)

Slottime = MAC and PHY delays + Air Propagation Time (max)

DIFS = SIFS + 2 * Slottime

Summary

Moderately long distance 802.11b links may work well "out of the box" due to the lax timings, and even more lenient MAC implementations by some manufacturers. With the right wireless card and some tweaking, 802.11b can maintain almost maximum theoretical throughput over very long distances and thus is the distance king.

However 802.11a is still the throughput king, but specialised cards that allow tweaking are certainly required for any distance links. Tweaking 802.11g requires a card that can be locked into 11g mode so that the slottime doesn't keep reverting every time a 11b client tries to connect. 802.11a wins out over 802.11g because there are more non-overlapping channels in the 5.8 GHz spectrum, meaning most 11a links will more likely be able to maintain their high throughput.

- shadey

AMTA website posts safety fact sheets on Wi-Fi

AMTA has posted two new fact sheets on its website to explain the safety of Wi-Fi and how it works and the range of radio communications in the community.

See their website for more details.

Antenna Polarisation

Antenna polarization is a very important consideration when choosing and installing an antenna.

Most systems use either vertical, horizontal or circular polarization. Knowing the difference between polarizations and how to maximize their benefit is very important to users.

Polarization
An antenna is a transducer that converts radio frequency electric current to electromagnetic waves that are then radiated into space. The electric field plane determines the polarization or orientation of the radio wave. In general, most antennas radiate either linear or circular polarization.

A linear polarized antenna radiates wholly in one plane containing the direction of propagation. Where a circular polarized antenna, the plane of polarization rotates in a circle making one complete revolution during one period of the wave. If the rotation is clockwise looking in the direction of propagation, the sense is called right-hand-circular (RHC). If the rotation is counter clockwise, the sense is called left-hand-circular (LHC).

An antenna is said to be vertically polarized (linear) when its electric field is perpendicular to the Earth's surface. An example of a vertical antenna is a broadcast tower for AM radio or the "whip" antenna on an automobile. Horizontally polarized (linear) antennas have their electric field parallel to the Earth's surface. Television transmissions use horizontal polarization.

Circular polarized wave radiates energy in both the horizontal and vertical planes and all planes in between. The difference, if any, between the maximum and the minimum peaks as the antenna is rotated through all angles, is called the axial ratio or elliptically and is usually specified in decibels (dB).

If the axial ratio is near 0 dB, the antenna is said to be circular polarized, when using a Helix Antenna. If the axial ratio is greater than 1-2 dB, the polarization is often referred to as elliptical, when using a crossed Yagi.

Important Considerations
Polarization is an important design consideration, as each antenna in a system should be properly aligned for maximum signal strength between stations. When choosing an antenna, it is an important consideration as to whether the polarization is linear or elliptical. If the polarization is linear, is it vertical or horizontal? If circular, is it RHC or LHC?

This is becomes a greater concern in Wireless Lan devices as line-of-sight (LOS) paths are required due to the low power levels involved, consequently the polarization of the antennas at both ends of the path must use the same polarization.

In a linearly polarized system, a misalignment of polarization of 45 degrees will degrade the signal up to 3 dB and if misaligned and 90 degrees the attenuation can be more than 20 dB.

Likewise, in a circular polarized system, both antennas must have the same sense. If not, an additional loss of 20 dB or more will be incurred. Also note that linearly polarized antennas will work with circularly polarized antennas and vice versa. However, there will be up to a 3 dB loss in signal strength. In weak signal situations, this loss of signal will mean a great deal.

Cross polarization is another consideration. It happens when unwanted radiation is present from a polarization, which is different from the polarization in which the antenna was intended to radiate. For example, a vertical antenna may radiate some horizontal polarization and vice versa. However, this is seldom a problem unless there is noise or strong signals are nearby.

Typical Applications
Vertical polarization is most commonly used when it is desired to radiate a radio signal in all directions over a short to medium range.

Horizontal polarization is used over longer distances to reduce interference by vertically polarized equipment radiating other radio noise, which is often predominantly vertically polarized.

Nevertheless both horizontal and vertical polarization may be deployed over long distance if a reflector is deployed to focus the energy being emitted.

So consequently the decision is using the polarization, which offers the best rejection of local unwanted signal.

Circular polarization is most often used in satellite communications. This is particularly desired since the polarization of a linear polarized radio wave may be rotated as the signal passes through any anomalies (such as Faraday rotation) in the ionosphere.

Furthermore, due to the position of the Earth with respect to the satellite, geometric differences may vary especially if the satellite appears to move with respect to the fixed Earth bound station. Circular polarization will keep the signal constant regardless of these anomalies.

These Antennas make very good point-to-point long run connections due to a combination of linear noise rejection and high gain. The two most common a crossed yagi or helix

When setting up an exclusive communications link, it may be wise to first test the link with vertical and then horizontal polarization to see which yields the best performance (if any).

If there are any reflections in the area, especially from structures or towers, one polarization may outperform the other. Further, if there are other RF signals in an area, using a polarization in the opposite predominant high level signals will give some isolation as discussed earlier.

On another note, when radio waves strike a smooth reflective surface, they may incur a 180 degree phase shift, a phenomenon known as specula or mirror image reflection. The reflected signal may then destructively or constructively affect the direct LOS signal.

Circular polarization has been used to an advantage in these situations since the reflected wave would have a different sense than the direct wave and block the fading from these reflections.

Diversity Antennas
Even if the polarizations are matched, other factors may affect the strength of the signal. The most common are long and short-term fading. Long term fading results from changes in the weather (such as barometric pressure or precipitation). Short term fading is often referred to as "multipath" fading since it results from reflected signals interfering with the LOS signal.

Some of these fading phenomenon can be decreased by the use of diversity reception. This type of system usually employs dual antennas with some kind of "voting" system to choose the busiest signal. This is commonly used in many 802.11 wireless network equipment.

However in theory for the best results when using external antennas they should be at least 20 wavelengths apart, so that the signals are no longer correlated, particularlly in medium and long-distance situations.

Bits and Bytes

Data Transmission conversion (kilobit):

Some sources define a kilobit to mean 1,024 (that is, 2^10) bits. Although the bit is a unit of the binary number system, bits in data communications are discrete signal pulses and have historically been counted using the decimal number system. For example, 28.8 kilobits per second (Kbps) is 28,800 bits per second. Because of computer architecture and memory address boundaries, bytes are always some multiple or exponent of two.

Easy dBs

Off the back of the meeting last night where we were talking about the power output of cards and
antenna gains. I'd thought I'd post how I remember the whacky world of dB gains.

Rule of Thumb: For power gain, every decade of dB adds a zero to the "10".

eg.
0dB = 1
10dB = 10
20dB = 100
30dB = 1000
40dB = 10000
etc.

Rule of Thumb #2: Every doubling of power is +3dB

eg.
100 = 20dB
200 = 23dB
400 = 26dB
etc.

This stems from a formula used to calculate gain in terms of dB,
Av(dB) = 10 log( Av )
Where Av(dB) is the gain in terms of dB, and Av is the raw gain which is determined by
dividing the output power by the input power,
Av=Po/Pi

Also as a side reminder
dBi - Gain of an antenna with respect to a unity-gain isotropic antenna.
dBm - Gain of an amplifier (power output of a transmitter) with respect to 1mW.

Edit: Those wanting to know the dBm of their card, just put the power figure in the formula I mentioned
above (ie. for a 350mW card, 10*log(350)= 25.4dBm)

Effective Isotropic Radiated Power (EIRP)

Effective Isotropic Radiated Power (EIRP) is the output power when a signal is concentrated into a smaller area by the Antenna.

An isotropic radiator radiates power equally in all directions, however a perfect isotropic radiator is only theoretical as even the simplest antennas will concentrate the signal in certain direction(s). E.g. a 1/2 wave dipole has a gain of 2.15 dBi.

The EIRP is calculated using this formula:

EIRP = Effective Isotropic Radiated Power

Pout = transmitter power output (dBm)

Ct = signal loss in cable (dB)

Gt = gain of the antenna (dBi) Pout - Ct + Gt = EIRP

When installing a wireless system with external antenna, your EIRP calculation should not exceed the class license limit. Other wise you must adjust either the transmitter power output, the length of cable and/or the choice of antenna.

Fresnel Zone

Here is scenario...

It’s early in the morning on a cool, clear day. The top of a proposed Air-Stream site is just visible through your binoculars and everything seems good

You go out and purchase and test the necessary wireless equipment, mounting an antenna on the rooftop, then fire it up, and… then nothing but problems.

The link does not seem to cooperate at all. It fades in and out, and the radio signal levels are low when there is any link at all. You check all the connections, twist and turn the antenna, and use your best language to get it to work… no improvement.

On first analysis it appears that some component in the wireless unit is malfunctioning, but the test worked properly and the units performed as expected.

Standing on the roof, you snap open your mobile and call another Air-Stream member. They listen to your story, and then they ask a question:

"Any chance that another signal is interfering with your signal?"

I checked, and can pick out a few other SSIDs but nothing on the same channel "Good", you reply

"Now, do you have clear Radio Line of Sight?" "Of course", is your response “I have some binoculars, and can see the other site from where I’m standing??”

They pauses and then ask "That’s good to know, but what about proper Fresnel Zone clearance?"

Fresnel Zone clearance????
At that moment, you begin to suspect that there are other factors other than a visual sight involved with establishing proper, usable Radio Line of Sight.

So what is going on here?
For two radios, or wireless units, to connect to each other, the radio signal must reach both units with adequate strength, and in a usable form.

For a wireless network spanning many kilometres these factors collectively are known as "Radio Line of Sight", and become very important indeed.

Visual and Radio line of sight: are they different?
Light and radio are both forms of electromagnetic radiation but operating at very different frequencies. Just because you can establish visual line of sight, or see a distant building with binoculars on a clear day, does not mean you can establish a wireless link between them.

What is the Fresnel Effect?
In the early 19th century French physicist, Augustin Fresnel (pronounced "Freh-Nel") made an important observation about the behaviour of light. Fresnel noted that a ray of light passing near a solid object is subject to diffraction, or bending.

This diffraction caused the intensity of the original light beam to increase or decrease depending on how near the object was to the beam. This characteristic of electromagnetic radiation is known as the Fresnel Effect.

Light and radio waves are subject to the same laws of physics, including the Fresnel effect. If an object like a mountain ridge or building is close to the radio signal path, it can affect the quality and strength of the signal.

Radio waves diffracted by such objects can affect the strength of the received signal. This happens even though the obstacle does not directly obscure the direct visual path.

This area, known as the "Fresnel Zone", and must be kept clear of all obstructions. That means the earth curvature, depth of the Fresnel Zone, and height of objects in the radio path must be added together to get the antenna mounting height. It’s usually adequate to use less than the full depth of the Fresnel Zone to calculate clearance.

How much Fresnel Zone clearance do I need?
60% of the Fresnel Zone (F) is the generally accepted portion which must be kept clear. This assumes that there are no buildings or other obstructions in the way. If such obstructions exist, their height must be added to the total antenna mounting height.

To see the distant end with binoculars, we need only elevate our eye high enough to clear the Earth’s curvature. Remember, you saw the top of the distant site. The problem was that you only confirmed visual line of sight, not radio line of sight.

When it came time for the radio signal to pass from site A to site B, the lack of adequate Fresnel Zone clearance caused signal diffraction, and degradation of the radio signal.

So what do you do?

• Use an antenna with a more narrow lobe pattern, usually a higher gain antenna will achieve this
• Raise the antenna mounting point on Site A and/or Site B
• Build a new structure, e.g. a tower tall enough to provide adequate clearance
• Increase the height of the existing antenna mounting point by installing a taller mast with stabilizing guy wires
• Locate a different mounting point, e.g. building or tower, for the antenna
• Remove the obstacle (such as taking a chain saw to that Tree)

LOS (Line of Sight)

802.11a and b wireless LAN equipment has proven to be a very useful and a low cost way to setup networks over distance and is commonly used by many individuals, community groups and small businesses.

However for most setting up a wireless network for the first time, one major hurdle that will almost always comes up is the problem of establishing good LOS between sites. LOS or Line of sight is a very important consideration, as without it, it would be impossible to establish a reliable network connection over a few hundred metres regardless of the antenna, equipment or mast deployed.

This is because the high frequency and low power of most standard wireless devices 802.11(a/b/g) is unable to pass through a solid object without a significant reduction and dissipation of the signal.

Where as good LOS it is not uncommon to see links established over 10kms with sustained data rates exceeding 18Mbps in 802.11a Unfortunately, in the real world good LOS between different locations is a rare coincidence for individuals working on their own and it is for this reason many community groups like Air-Stream Wireless have been formed.

By establishing a group, members can help each other by establishing a shared network where specific sites with good LOS become the relay points for others without good LOS consequently overcoming many topographical barriers that an individual would find difficult to overcome on their own.

MIMO and 802.11n

MIMO an acronym for multiple input, multiple output, and is a system which is deployed along with OFDM (Orthogonal frequency-division multiplexing) in the new 802.11n standard. This new standard offers many advantages over conventional standards such as 802.11g Wireless LAN equipment of which we have become familiar.

MIMO a system which exploits multiple transmitters and antennas to increase the bit rate in a wireless LAN link with no additional power or bandwidth consumption using a method called Spatial Multiplexing (SM). The benefits of MIMO over conventional 802.11g equipment is pronounced.

Benefits include:

• Improved signal to noise ratio through increased antenna array gain,
• Improved link reliability using phase nulling techniques
• Near and Non LOS performance enhancement
• Improved ability to ignore other signals which inhabit the same band
• Increased throughput due parallel data channelling.

Here is a simplified summary of how it all works

The input data stream is split into independent sub-streams which together occupy less bandwidth than is required to transmit the original stream on a single channel. These sub-streams are applied separately to individual transmitters and antennas on the same frequency, where the receivers at the other end recover each sub-stream and merg them back together.

Due to the presence of various scattering objects eg: buildings, walls, cars, trees, etc. signals experience a multi-path propagation and when it is captured by the receiver antenna these signals will arrive with random phase and amplitude. In conventional 802.11g equipment only the strongest signal is used and the other mulit-path signals are rejected as noise.

However in a MIMO device this is turned to an advantage as these deferent phases and amplitudes will have a specific spatial signature. The receivers can be viewed as a bank of superposed spatial weighting filters where every filter aims at extract one of the multiplexed sub-streams by spatially nulling the remaining ones. This not only allows the added benefit of array gain due to multiple antennas, but also diversity techniques which reduce signal fading.

The disadvantages of the MIMO system is mostly the need for multiple Antennas; the cost of the equipment compared to existing equipment available and limited open source driver support.

However as poeple become more aware of the posibilities the standard it is certain to become popular and with this the price should come down significantly. This I'm sure also will see more manufacturers making code available for the Open Source Community, which will enhancing their competitive advantage over other brands and boarder support by wireless network communities and enthusiasts.

Minimising Interference

Users of wireless LAN equipment over distance are increasingly being effected by rising levels of interference due to the ubiquitous nature of wireless usage in the home and office, further fueled by the low costs, easy setup and the potential benefits that the technology offers.

Also access to the radio bands used by this equipment is relatively unconstrained, called the 'public park' concept the planning objective of regulative authorities is for all users to be able to access a small portion of the total resource and to share that resource in a way that requires minimal regulatory intervention provided the power is kept well down.

The use of a 'public park' approach is administratively efficient and gives great freedom to users, but the price of this freedom is increased risk of interference. What is often miss-understood by many users of wireless LAN equipment is that this framework equally applies to all users regardless if you are a telecommunications carrier or an individual.

Clearly the very thing that has created an environment where communities can establish wide area networks like Air-Stream is the same environment which has created the interference problem.

Consequently, minimising the impact of interference through public awareness, and providing an open platform for users to share information to maximise the effectiveness of their equipment and minimising interference is important to all.

What is a dB?

Newcomers to wireless technology often find terms such as dB, dBm etc confusing. This document explains these terms.

We use certain types of antennas because they have “gain” – they increase signal strength. They don’t magically create extra energy though, they direct radio signals into a smaller beam in the same way a spot light does. The higher the gain the narrower the beam and the more concentrated power – in certain directions only though!

We often talk about this gain in terms of ratios, because the gain is independent of the power level – an antenna that doubles the signal strength of a one watt transmitter will also double the signal strength of a ten watt transmitter.

You can also have losses – a poor cable might lose one half (or more) of the signal power. This is also independent of the absolute power level – one watt becomes half a watt, ten watts becomes five, etc.

Ratios are messy to use though when using several of them together – imagine “I have a seventeen times antenna with a one third power loss in my cable and one tenth of my power lost in the connectors”. It’s hard to figure out just how much overall gain or loss that represents.

To make it easier, we work with deci-Bells (dB), which are defined as ten times the logarithm of the ratio. The beauty of this is that to multiply gains (or losses) we just add the dB numbers. (Gain will be a positive dB number, while loss will be negative, so subtracted) So now “I have a 15dB antenna, with 3dB of cable loss and 2dB of connector loss – a total of 10dB gain”. Much easier!

Here are some examples of dB ratios:
+3dB is doubling the power, -3dB is only a half.
+6dB is Quadrupling power, -6dB is only a quarter.
+10dB is 10 times the power, -10dB is only a tenth.
+20dB is 100 times the power, -20dB is only one percent.

(You can now see why the “ten times” factor is used – it avoids fractions in the log values for commonly encountered ratios)

All of the above deals with RATIOS, which are independent of power. So it’s meaningless to say “How much power will a 23dB antenna give me” – the antenna gets as much power as the transmitter feeds it, but focuses it to give the effect of a 23db stronger (200 times more powerful) transmitter – in the focus direction only. In fact, the effective width of the strengthened signal is specified as “degrees of beamwidth” and is the number of degrees between the points at which the gain falls off by 3dB.

We often talk about the “Effective Radiated Power” and that is the equivalent power level produced by the transmitter/antenna combination (in the highest gain direction). So a 1 watt transmitter with a 20dB (100 times) antenna is producing a ERP of 100 watts.

High gain antennas have narrow beamwidth, and so can be harder to align. It should be noted that gain can be achieved in either the horizontal or vertical plane (or both). Most antennas have quite different patterns of radiation in the vertical and horizontal planes, with different antennas chosen for the different pattern according to their function. Antennae also have a “polarisation” – either horizontal or vertical, which defines the way in which the radio waves are transmitted, but the main connection between signal strength and polarisation is that having different polarisations between transmitter and receiver gives another 20dB or more of loss!

Finally, another term encountered is dBm, and this one IS related to power. Zero dBm is defined as one milliwatt (one thousandth of a watt) and so transmitter powers are often expressed in terms of this reference. This is NOT the same as antenna gain – this is real power. Receiver sensitivity is also expressed in terms of how many dBm or what power level is required to receive a signal. So if I have a 20dBm transmitter, a 15dB gain antenna at each end, 110dB of path loss (signal attenuation in the atmosphere) and a –90dBm receiver, can I get a signal through?

Add them up: 20 plus 15 minus 110 plus 15 gives -60dBm, so I will theoretically have a signal of 30dB more than the minimum I need, so it should be a good path. Of course, this is only theoretical, trees and other obstructions can reduce the signal dramatically, but this is a good starting point before a real-world trial.

Steve Fraser

Channels for 802.11b

802.11b applies to wireless LANs and provides 11 Mbps transmission (with a
fallback to 5.5, 2 and 1 Mbps depending on Range and Signal Strength) in the
2.4 GHz band. 802.11b uses only DSSS (Acronym for direct-sequence spread spectrum.
DSSS is one of two types of spread spectrum radio.) 802.11b was a 1999 IEEE
ratification to the original 802.11 standard.

Channels for 802.11g

802.11g is a proposed standard, describing a wireless networking method for
a WLAN that operates in the 2.4 GHz radio band. By using OFDM (Orthogonal Frequency
Division Multiplexing) technology, 802.11g-based WLANs will be able to achieve
a maximum speed of 54 Mbps. 802.11g-compliant equipment, such as wireless Access
Points, will be able to provide simultaneous WLAN connectivity for both 802.11g
and 802.11b equipment.

Channels for 802.11a

Channel Separation Layout

BGP (Border Gateway Protocol)

The Border Gateway Protocol (BGP) is an inter-autonomous system routing protocol. An autonomous system is a network or group of networks under a common administration and with common routing policies. BGP is used to exchange routing information for the Air-Stream WAN and is the protocol used between our Access Points Routers (APR).

BGP is a very robust and scalable routing protocol, as evidenced by the fact that BGP is the main routing protocol employed on the Internet today. To achieve scalability, BGP uses many route parameters, called attributes, to define routing policies and maintain a stable routing environment.

In addition to the BGP attributes, classless inter-domain routing (CIDR) is used to reduce the size of the routing tables. For example, assume that an APR such as Julia Farr owns the IP address block 10.123.x.x, this block would consist of 256 address blocks 10.123.0.x through to 10.123.255.x. If the APR assigns each block to a member without CIDR it would be necessary for the APR to advertise 256 address blocks to its peers. But CIDR can subnet the address space and advertise only one block 10.123.x.x which is much smaller as it is rendered obsolete by CIDR, allowing a significant reduction in the BGP routing tables.

BGP Attributes
Routes learned via BGP have associated properties that are used to determine the best route to a destination when multiple paths exist to a particular destination eg where an APR has multiple backbones. These properties are referred to as BGP attributes and include:

• Weight
• Local preference
• Multi-exit discriminator
• Origin
• AS_path
• Next hop
• Community

Weight Attribute
Weight is an attribute that is local to a router. The weight attribute is not advertised to neighbouring routers. If the router learns about more than one route to the same destination, the route with the highest weight will be preferred and will be installed in the IP routing table.

Local Preference Attribute
The local preference attribute is used to prefer an exit point from the local autonomous system (AS). Unlike the weight attribute, the local preference attribute is propagated throughout the local AS. If there are multiple exit points from the AS, the local preference attribute is used to select the exit point for a specific route.

Multi-Exit Discriminator Attribute
The multi-exit discriminator (MED) is used as a suggestion to an external AS regarding the preferred route. The term suggestion is used because the external AS that is receiving the MEDs may be using other BGP attributes for route selection.

Origin Attribute
The origin attribute indicates how BGP learned about a particular route. The origin attribute can have one of three possible values:

• IGP is the route interior to the originating AS. This value is set when the network router configuration command is used to inject the route into BGP.
• EGP is the route learned via the Exterior Border Gateway Protocol (EBGP).
• Incomplete is where the origin of the route is unknown or learned in some other way.

AS path Attribute
When a route advertisement passes through an autonomous system, the AS number is added to an ordered list of AS numbers that the route advertisement has traversed.

Next-Hop Attribute
The EBGP next-hop attribute is the IP address that is used to reach the advertising router. For EBGP peers, the next-hop address is the IP address of the connection between the peers. For IBGP, the EBGP next-hop address is carried into the local AS, as illustrated in
Therefore, it is important to have an IGP running in the AS to propagate next-hop routing information.

Community Attribute
The community attribute provides a way of grouping destinations, called communities, to which routing decisions (such as acceptance, preference, and redistribution) can be applied. Route maps are used to set the community attribute. Predefined community attributes are:

• no-export—Do not advertise this route to EBGP peers.
• no-advertise—Do not advertise this route to any peer.
• internet—Advertise this route to the Internet community; all routers in the network belong to it.

BGP could possibly receive multiple advertisements for the same route from multiple sources. BGP selects only one path as the best path. When the path is selected, BGP puts the selected path in the IP routing table and propagates the path to its neighbours. BGP uses the following criteria, in the order presented, to select a path for a destination:

• If the path specifies a next hop that is inaccessible, drop the update.
• Prefer the path with the largest weight.
• If the weights are the same, prefer the path with the largest local preference.
• If the local preferences are the same, prefer the path that was originated by BGP running on this router.
• If no route was originated, prefer the route that has the shortest AS path.
• If all paths have the same AS path length, prefer the path with the lowest origin type (where IGP is lower than EGP, and EGP is lower than incomplete).
• If the origin codes are the same, prefer the path with the lowest MED attribute.
• If the paths have the same MED, prefer the external path over the internal path.
• If the paths are still the same, prefer the path through the closest IGP neighbour.
• Prefer the path with the lowest IP address, as specified by the BGP router ID.

Sample Config Files (for Quagga/Zebra)
Basic settings for a quagga BGP setup:

zebra.conf:
-------------------------
hostname blah                # your hostname
password blah                # your password
enable password blah
interface rl0                # your interfaces
interface wi0
interface wi1
line vty
-------------------------

bgpd.conf:
-------------------------
hostname blah
password blah
enable password blah
router bgp 655xx            # your AS
network 10.x.x.x/27            # 
network 10.y.y.y/30            # your networks
network 10.z.z.z/30            #
neighbor 10.y.y.y remote-as 655yy    # peer1
neighbor 10.z.z.z remote-as 655zz    # peer2
line vty
------------------------- 

Good resources for BGP routing are:

• Quagga an OpenSource Routing Standard that runs on Linux and *BSD
• Cisco's Border Gateway Protocol Page
• BGP on OpenWRT form martybugs
• BGP on Quagga

Sorry if this is a bit of a glossary more details about dynamic routing can be found on www.quagga.net

Firewalling
Once your machines are routed onto the wireless network you may want to think about firewalling to keep your computers in and to keep unwanted packets out. This should all be done on the same machine that is doing the routing.

Sam Hodge

It is preferable that people be as self sufficent as possible, because the network administrators are under enough load as it is.

If all of this routing stuff is of interest to you I suggest you offer to lend the network administrators a hand or write a brief how-to on the Air-Stream site.

LDAP

The aim of the LDAP service is to centralize user information for access by different network services e.g. Domain Controllers, Email Severs, Web Servers and other complient services.

It works like a centralised directory service allowing both servers and users to lookup and search user details. LDAP Servers require very low system resources and can be synchronized with other LDAP Servers to offer very high levels of reliability.

LDAP stands for Lightweight Directory Access Protocol. A language based on the X.500 directory standard that allows clients and servers to communicate. The LDAP server allows access to the hierarchical structure of an active directory.

Managing Collections of Sub-Networks

When a router receives a packet of information (as it does thousands of times per second) it inspects the IP Address of that packet, and based on that, can make decisions on which physical path to send it through.

This process is known as routing the packet. Special software protocols have been created to support the routing of network traffic between subnetworks. These protocols operate with ‘smart’ algorithms that can adapt the flow of network traffic when problems occur. Protocols such as Border Gateway Protocol (BGP) and are widely used across the Internet today.

The algorithms employed by these protocols provide great network stability ensuring that if one network connection is lost, the router can quickly adapt to send data through an alternate network path. Consequently, the greater the number of network connections that are available, the greater the reliability and bandwidth for its users.

Managing Networked Computers

Computers on a network communicate with each other using a special numbered addressing system. This is known as Internet Protocol (or IP). Each computer has a unique IP Address, which is four sets of numbers from 0-255, separated by a decimal point. This gives a total possible address space from 0.0.0.0 to 255.255.255.255. For example: 203.152.23.202 is an Internet IP Address.

IP addresses can be grouped into smaller logical segments of the entire address space, which can then be assigned to computers in a LAN. Breaking up IP Address space into smaller sub-networks is known as Subnetting.

This allows for logical control of data between LANs, and maps well onto the physical network design outlined.

Open WRT and OLSR Working Group

A group has beem formed by Air-Stream members to work with interested code developers and every day people to look into practical ways to use OpenWRT able wireless devices and OLSR to build a very low cost grass roots community wireless networks.

There is no need to be a Air-Stream Member as anyone can participate, to join trials of the mesh network, all you need is a OpenWRT able wireless device , volenteer and participate.

ipkg install quagga
ipkg install quagga-zebra
ipkg install quagga-bgpd

vi /etc/quagga/zebra.conf

vi /etc/quagga/bgpd.conf

touch /var/bgpd.pid
chmod 777 /var/bgpd.pid
touch /var/zebra.pid
chmod 777 /var/zebra.pid

/etc/init.d/S35quagga

svn co https://svn.openwrt.org/openwrt/trunk/

make menuconfig

make

Note: Kamikaze only contains the essential set of packages, extra packages can be found in the 'Kamikaze packages' directory above. To use these packages simply symlink them into Kamikaze's package directory.

bin

Physical Network Structures

Groups of computers can be connected in many different configurations.

A simple Local Area Network (LAN) consists of a few computers, which are directly connected to each other.

This allows for high-speed communication between the participating machines, but offers little flexibility for adding more clients. Networks like this are generally confined to a relatively small area, such as a home, business or office.

As more clients are added to the LAN, we require more efficient control of network traffic. This is achieved through the deployment of devices such as Switches and Routers.

A network Switch (S) operates like a central hub through which several computers can communicate at high speed. Computers can send out network broadcasts to inform all other computers of their presence, and high speed peer-to-peer communication is maintained.

Routers can be used to interconnect several LANs together, forming a Wide Area Network (WAN). A Router (R) is used at each connection point between the LANs to control and monitor the passage of data.

The use of Routers allows confinement of network broadcasts to the Local Network only, instead of traversing the entire network, and reducing overall efficiency.

The flow control and management of data as it traverses a physical network is known as Routing. Perhaps the best example of this network structure is the Internet, built upon these same principles; it is a worldwide collection of interconnected.

Wireless Client Ethernet Bridge

There are two network configurations possible for a client host or network when using an external wireless device. The most simple is a bridged configuration where the hosts on the members network are bridged directly to the wireless network and take IPs from the subnet of remote access point. The other type is a routed configuration in which the members network is given a seperate subnet that is routed onto the network. This page deals with devices capable of bridging (but not necessarily routing.)

Unlike internal wireless devices such as PCI, Mini-PCI, PCMCIA and USB adapters, an important feature required when using the alternative wireless Ethernet device is the ability to bridge or clone the Mac address of the device it is connected to allow seemless packet forwarding between the wireless network and the members network or computer.

The aim being to connect the Mac addresses of the router and the members without wireless Ethernet device(s) Mac address used in the network.

However the confussion lies when members purchase an AP which works in both AP mode and client/bridge mode such as the Classic Minitar "the ideal" but remember that this is only the ideal if you intend that at a later stage to use it in other modes.

In most cases an AP that works in both modes are capable of connecting using only one IP address. However unless the AP, when operating in client mode can bridge correctly or can clone the members Mac address, it will not forward packets correctly and disallow the use of other subnets.

Some examples of bridges and APs that could be used as a Wireless Client Ethernet Bridge:

• Linksys WRT54G / WRT54GL Router AP only, but can run in Bridge if setup with openwrt (b/g) $108.00
• Linksys WET54G Wireless to Ethernet bridge only (b/g) $148.50
• Linksys WGA54G Wireless to Ethernet bridge only (b/g) $134.00
• Linksys WET54GS5 Wireless to Ethernet Bridge with 5-port Switch (b/g) $149.75
• Senao NL-2611 CB3 Deluxe AP/Bridge (b) $190.00
• Senao NL-3054 CB3 Plus Deluxe AP/Bridge/Client (b/g) $225.00
• Netgear WGE101 Wireless to Ethernet bridge Only (b/g) $139.00
• Dlink DWL900+ Wireless Access Point AP/Bridge/Client/Repeater (b/b+) $134.99
• Dlink DWL-810+ Wireless to Ethernet bridge only (b/b+) $134.95
• "Freenet Antennas" UltraWAP 802.11 b/g AP/Bridge/Client/Repeater $99.00 (90 mW TX) to $170.00 (200 mW TX)
• NetComm NP5410 Wireless to Ethernet bridge only (b/g) $155.76
• Edimax EW-7206APg Wireless Access Point AP/Bridge/Client/Repeater (b/g) $100

Most 802.11g devices will operate in 802.11b automatically but should be set to 802.11b only in the firmware to improve performance.

Note: Air-Stream is not a supplier of equipment and prices listed are only listed as a guide only. Please visit member discounts for some of our preferred suppliers.

Some definitions:

Access Point Mode
Access Point mode is used to connect to one or more wireless clients. Wireless clients can only communicate to APs in Access Point mode.

Access Point Client / Wireless Client Mode
AP Client or Wireless Client mode allows the Access Point to effectively become a wireless client to another AP. In essence the AP has now become a wireless adapter card. You would use this mode to allow the device to communicate with an existing AP. Wireless cards will not communicate with access points in AP Client / Wireless Client mode.

Point-to-Point / Wireless Bridge
Point-to-Point / Wireless Bridge mode allows the Access Point to communicate with another Access Point capable of point-to-point bridging. However, be aware that most manufacturers use proprietary settings when enabling bridging mode in the Access Point. A typical scenario for this selection is connecting two routers at Mac level through a wireless connection (ie mac3 and mac2 in the diagram above)

Point-to-Multipoint / Multi-point Bridge
Point-to-Multi-point / Multi-point Bridge mode is the same as Point-to-point / Wireless Bridge mode, however this mode allows you to use more than two Access Points.

Repeater Mode
As a Wireless Repeater, the Access Point extends the range of the wireless network by repeating the wireless signal of the remote AP (Access Point). The Ethernet MAC address of the remote AP is required for the Access Point to act as a wireless range extender. The repeater appears to the remote AP as just another client, so this mode does not require any special proprietary bridging protocols.

Air-Stream IP Addressing

Air-Stream uses private addressing from the 10/8 range utilising 10.96.0.0/11, this is designed to allow interconnection into wireless networks around Australia should the day ever come.

These are:

• VIC - 10.0.0.0/11
• WA - 10.32.0.0/11
• NT - 10.64.0.0/12
• ACT - 10.80.0.0/12
• SA - 10.96.0.0/11
• TAS - 10.128.0.0/11
• QLD - 10.160.0.0/11
• NSW - 10.192.0.0/11
• NZ - 10.224.0.0/11

General rule of thumb is that an Access Point will be assigned 1x/27 for the Nodes hanging off it, 1x/27 for the Local LAN at the access point if applicable and each node will be assigned a single address from the Access Points /27 pool to which they then can route their very own /27 to if they wish.

In some circumstances an AP may require additional IP’s in which case another /27 is made available or a single /26 can be provisioned, it is unlikely and not very smart to run more than 30 nodes off a single Radio so the above would apply only to AP’s with multiple radios offering node access.

The majority of the Air-Stream backbones are run on /30’s

The Addressing scheme has been designed to allow scalability while also allowing good use of VLSM(Variable Length Subnet Masking) in the future to summarize route tables, each area is designated an inner and outer segment, inner being within 20km of the CBD and outer being further than 20km.

• /27 is 30 usable IP’s, a /26 is 62 usable IP’s and a /30 is 2 usable IP’s.
• An Access Point is the Radio that nodes terminate on, would almost always go into a router at the same location.
• A Node is an end users radio that is acting as a client to the Access Point.
CBD is the Central Business District 

This is how IPs are allocated, based on Adelaide CBD being the centre:

Air-Stream's Routing

Air-Stream primarily uses BGP for routing around the domain, some AP owners choose to run another protocol such as OSPF/RIP locally then redistribute into the BGP network, this is fine.

There are filters run on the Air-Stream operated routers to control routing updates and what can and can’t be routed, it’s generally fairly open.

Each AP is assigned its own Private AS (Autonomous System) and AP owners have full control of their own AS in regards to what goes in and out. Initally we started off with OSPF but ran into multicast and topology issues, BGP allowed us to work around this while providing added control over the network so it was a win win situation.

As previously mentioned we like to summarise addresses where possible at the routers and have a good design in place to allow for huge growth. We are able to provide BGP templates for people to use as configs, it really isn’t that hard and configuration isn’t overly advanced for the nodes, about the most interesting thing is that they run in a route reflector client mode due to the topology and iBGP.

QoS
We have QoS(Quality of Service) in place on the Air-Stream routers giving precedence to traffic seen to be important by us(the committee) and the members, we are always open to new suggestions of what should be given more precedence, it’s not the easiest thing to implement when you are going between cisco,linux and bsd routers around the network but it seems to work quite well.

All-in-one Client Premesis Equipment (CPE)

Often referred to as Client Premesis Equipment (CPE) there are a number of vendors who provide integrated solutions for connecting to existing wide area wireless networks such as the Air-Stream wireless network. This equipment integrates the job of host, wireless radio, antenna and accessories into one product. The main advantage of this is the cost saving and simplicity associated with buying a single product. The main disadvantage is the lack of options in customisation, software and upgradeability.

Hosts

A computer board that controlles one or more wireless radios.

Wireless Radios

A module or device which provides IEEE 802.11 a/b/g/n MAC layer to a host and a physical layer to an antenna.

Dbii Networks - True Integrated Lightning & ESD

Dbii Networks produces a range of high quality wireless cards that integrate Lightning & ESD* protection into their entire range of 802.11a/b/g/n with robust surge protection built in. It employs patent pending architecture that integrates the protection for the antenna port from static electric build-up during thunder storms and other power surges.

The card feature good output power performance and high receive sensitivity as they are designed with long distance outdoor wireless networks in mind. The cards also have built-in Heat-sinks that make them ideal for Australian conditions.

Dbii Networks has recently given Air-Stream Wireless a number of samples to trial on our network, which are currently with the Network Planning Team for deployment.

Units for testing include:

• F20-Pro - 2.4Ghz 802.11b/g
• F50-Pro - 5.8Ghz 802.11a
• and the F52N-Pro N card for 2.4 & 5.8Ghz a/b/g/n

Dbii trial planned for new link between MOB and Seaview Downs

This is our first real-world trail of the F20-Pro - 2.4Ghz 802.11b/g and the F50-Pro - 5.8Ghz 802.11a mini PCI cards produced by Dbii Networks which will soon be installed at two new core nodes in the South Metro Network marked in red below.

The new site at Seaview Downs will provide a back-haul link between Melrose Park (marked Blue) and a large commercial building at Bedford Park which will significantly increased coverage in Marion area.

Edimax EW-7206APg

Edimax EW-7206APg is a new ethernet access point (AP) that is similar to the old Minitars but also have a 802.11g mode. They support all the features of the Minitar like client mode and MAC cloning.

Download the factsheet (Cached)
Download the users manual (Cached)

Mass production of these units have just begun, hopefully these units will proove to be as good as the old Minitars and will help the network grow. These units will benifit clients who just want to connect to an access point and dont have *nix skills.

---

Comparisons to Minitar MNWAPB

Similarities:
Size/form factor: Identical (same factory)
Power/POE: Identical
Features: All MNWAPB features are there, including setting MAC addres on a 'client' (MAC cloning).
TX Power: Same (60 mW) in 802.11b mode.
Antenas connectors: 1 x RP-SMA
Price: About same as MNWAPB

Differences:
+ 802.11g
+ 'Universal repeater' mode. This is a simultaneous AP+Client. And the AP and client can have different SSIDs

Link to info about the radio inside

Edimax EW-7206APg Product Page

Below is a copy of the page from http://www.edimax.com.tw/html/english/products/EW-7206APg.htm

EW-7206APg
Wireless-g 54Mbps Access Point Complies with the IEEE 802.11g/b 2.4GHz specification RP-SMA Detachable antenna WDS Bridge Mode supports Robust Wireless LAN Security Web Configuration, Firmware upgradeable via Web
Datasheet  User Manual
Key Features  IEEE 802.11g/b Wireless LAN Access Point Acting as a bridge between the wired Ethernet and the 2.4GHz IEEE 802.11g/b wireless LAN, this wireless LAN access point can let your wireless LAN client stations access both the wired and the wireless network nodes. WDS Bridge Mode (Repeater Mode) The WDS (Wireless Distributed System) function lets this access point act as an wireless LAN access point and repeater at the same time. Users can use this feature to build up a large wireless network in a large space like airports, hotels and schools ¡Ketc. This feature is also useful when users want to bridge networks between buildings where it is impossible to deploy network cable connections between these buildings. Station Mode (AP Client Mode) By setting this access point into station mode and connecting to a network device¡¦s Ethernet port, it can let a network device that originally only supports wired Ethernet access the wireless LAN easily without changing any configuration. Robust Wireless LAN Security Except for the basic security control by using ESSID and 64/128 bit key length WEP encryption, this access point also supports the advanced security features, like MAC access control and hide ESSID. It provides a total solution for you to build up a secure wireless LAN network environment that can prevent from all kinds of hacker intrusion. RP-SMA Detachable Antenna This access point provides a standard RP-SMA antenna connector that can let you apply all kinds of high gain antennas. This can help you enlarge your wireless LAN coverage. Web Configuration You can configure this access point through the friendly Web user interface with a browser.   Specifications  Model NO. EW-7206APg CPU Realtek RTL8186 RF Module Realtek  RTL8225 RAM 8MB Antenna RP-SMA Detachable Antenna Power 12V DC, 0.5A Linear Power Adaptor Dimension 30(H)*127(W)*96(D) mm Temperature 0~40ºC Humidity 10~90% (Non-Condensing) Certification FCC Class B, CE Mark

Minitar MNWAPB

Parts this page are from the original page of the old Air-Stream website

NOTE: These units are no longer being manufactured.

Spec Sheet:

http://www.minitar.com/index.php?maincat=product&cat=wireless&prod=wls_ap&page=2
Manufacturer: http://www.minitar.com/
Drivers: http://www.minitar.com/index.php?maincat=download
Model Number: MNWAPB
Interface Type: Wireless, 10/100M Ethernet
Power Output: ~18dBm (60mw)
Power Requirements: 12v @ 0.5A
Connector Type: RP-SMA
Transmit Power: 18dBm (typical)
Mounting Type: comes with screws for mounting on a wall and rubber stoppers. The AP case also has mounting lugs on the base.
Protocol: 802.11b, 802.1x
Security: 64/128-bit WEP
Chipset: Realtek RTL8181 (200MHz MIPS)
Dimensions: 30(H) x 127(W) x 96(D) mm
Price: $75-100 retail (no longer being manufactured)

Overview

The Minitar Wireless Access Point acts as a bridge between the wired Ethernet and the 2.4GHz IEEE 802.11b wireless LAN, this wireless LAN access point can let your wireless LAN client stations access both the wired and the wireless network nodes.

The client mode has been successfully tested with hostAP and various hardware APs with no known issues.

note: DHCP server) & Station Mode (AP Client Mode) are available with the firmware upgarde available from the site. WDS Bridge Mode (Repeater Mode) is not currently availible until a new firmware is released.

Minitar AP Power Usage
AP State	Power Usage (mA)	Average Usage (mA)
Idle	140 - 160	155
Full 11mbps (600kbps) TX	220 - 230	225
Full 11mbps (600kbps) RX	190 - 195	195
Tests were conducted with a Minitar AP (with 2.39 firmware), Supplied Minitar Power Supply, Apple iBook (with Airport 802.11b), and Digital Multimeter.

Other Reviews

Minitar Pro's and Cons
^ Note: to fix "Routing via a MNWAPB Client (station) broken" in the above article - change the mac address of the router to the mac address of the minitar (Linux: " ifdown eth0; ifconfig eth0 hw ether 00:11:22:33:AA:BB; ifup eth0 " changing eth0 and the mac address as appropriate ) -- fix courtesy of ben"

Known to be fixed in latest firmware upate

Image

The Minitar MNWAPB, the outside and the insides.

Created by: FuNcHi last modification: Sunday 30 of May, 2004 [08:11:45 UTC] by FuNcHi

Further information by Didz

Other Settings

Log in to the MNWAPB and type in "hwset.asp" after the IP to select more options. you must be using 2.53 firmware.

How to tell its a MNWAPB

Look at the underside of the case and look at the white label in the middle

Coaxial Cables

To connect an antenna to a wireless radio invariably requires one or more lengths of of coaxial cable terminated in the right connectors (plugs.)

Antennas

Antennas are the most visible part of wireless communication and play the most important role in guiding the radio frequency signals through the air. Antennas are where the 'wireless' part of wireless networking come in to play.

SuperPass 2.4GHz 8dBi Omni-Directional Antenna (SPDG16O)

This antenna is made by a Canadian antenna manufacturer and has been found to be very rugged and a solid performer for Air-Stream access points offering access to a 360 degree area. A simple but effective antenna design for basic 802.11b/g coverage.

Quick Specs
Gain: 8dBi
Polarization: Vertical, Linear
3dB Horizontal Beamwidth: 360°
3dB Vertical Beamwidth: 18°
Connector: Female N, Bottom-Feed

See the SuperPass product page for more information.

Noteable achievements involving the SuperPass Omni

• 12km link across the eastern/northern suburbs
• 42km link to Woolsheds
• Over 100 years of combined operational service in the wider Air-Stream network

---

Possible mounting arrangements for the SuperPass omni.

Enclosures and Accessories

Mounting and powering electronics in harsh environments such as outdoors or in roof cavities requires special consideration.

802.11n mimo trials begin

The Air-Stream Wireless Network Planning Team reported at our last meeting that they are currently testing the feasibility of using 802.11n on 5.8Ghz to increase through put on back haul links in the network. As with all things the best way to learn is by doing and this hands-on experience will be invaluable to the ongoing viability of the network into the future. Current testing is demonstrating exceptional performance over distances with links of 10kms showing it maybe possible to achieve synchronous data-rates of 90Mbps.

• MikroTik Router OS
• Routerboard RB433 and RB800
• Ubiquiti Networks, Inc. Rocket Dishes
• Ubiquiti Networks, Inc. Rocket M

AirLive ClearSignal Technology

AirLive WN-5000R Review - 802.11n

Air-Stream Wireless is very pleased to announce that AirLive, OvisLink Corp have provided two of their new WN5000R 802.11n wireless routers to put through their paces. With the success of our initial review of the 802.11n standard we have kept looking for other user-friendly equipment to conduct further field tests and the AirLive WN-5000R seems to certainly fit the bill.

Under the bonnet of the WN5000R - 802.11n

Under the bonnet of the new WN5000R 802.11n wireless router we find the Ralink RT2800 802.11n Chipset that consists of two highly integrated ICs (RFIC and BB/MAC IC) that fully comply with current draft IEEE 802.11n and IEEE 802.11a/b/g standards. The Ralink chipset is feature-rich system of 2 transmitter 3 receiver (2T3R) architecture to offer reliable wireless connectivity.

Other hardware details

Interface	1 x 10/100Mbps WAN port 4 x 10/100Mbps switching LAN ports Auto MDI/MDI-X functions
CPU	Ralink RT1310
Radio	Ralink RT2800 802.11n Chipset
Flash	4 MB NOR Flash
RAM	16 MB SDRAM
WAN Port	10/100M UTP Port x 1
LAN Ports	10/100M UTP Port x 4
Antenna	Fixed Antenna x 3 (2T3R MIMO Technology)
Power	12VDC, 1A Switching Power Adaptor
Temperature	10~40°C
Humidity	10~90% (Non-Condensing)
Product Weight (g)	261 g
Product Size ( L x W x H (mm) )	187 x 100 x 30 mm

Outdoor 802.11n

We have all been wowed by the potential speed and performance of 802.11n indoors.

Q: But how does it perform outdoors

A:Well there are lots of variables here but test have shown the following.

* Distance: 0.95 km ~ 80 Mbps
* Distance: 1.75 km ~ 60 Mbps

Greater then two kilometers nothing? but I imagine that this is a software Mac timing issue, and so a better result could be achieved with directional antenna and software drivers for PCI cards.

Put not bad for a retail hardware hack, trial.

Outdoor 802.11n - Construction

Being able to operate from a 12VDC power supply and run in bridge mode the AirLive WN-5000R offers great flexibility to test them out in the field and over the coming months I'll be going out-doors and across Adelaide testing them in a variety of situations.

As part of the process of testing the equipment in the field I have fully water proofed the AirLive WN-5000R mounting it on a fold-up stand for easy storage, transportation and installation out in all weathers, not that I expect any rain this January.

The units where very easy to re-house with only three screws holding the case together and then another four holding the pcb in place. The only issue is the need to solder the pigtails directly to the PCB as the AirLive WN-5000R has no external or internal connectors.

The next step is to have something to download and so I've pulled an old Ethernet NAS drive apart and striped out the PCB and made a plate to mount the PCB in the case.

Rather than use a conventional hard-drive which uses a lot of power, I'm using a Compact Flash Card as the unit will be used out in the field with batteries. However where mains power is available a suitable PC with hard disk will be used.

It should be noted though, that despite 802.11n being able to achieve a throughput of up to 300Mbs (in range), any wired 100Mb Ethernet device connected to the AP will limit the ability to do any faster than that wired network. This is further impacted by the media and CPU speed. So a NAS drive with a Flash Card will never do 802.11n justice as speeds are significantly reduced by the storage media's ability to read/write data and in the case of a flash card this is poor to say the least, but nevertheless will help greatly in the field to test link quality and compare between different scenarios.

Following this, I also needed an easy way to setup the AP and Antenna when out in the field and so I've used a telescopic collapsible stand, that I found in the hard rubbish. I also Pot-riveted some antenna brackets to support the three high gain Omni and attached the AP enclosure in the usual way with aluminum angle and a U clamp.

I then attached 10 meters of Ethernet cable which is wired for POE, fortunately the NAS drive was also 12V, so this also has been a simple process.

Linksys WRT300N Review

Linksys, a division of Cisco Systems, Inc. has donated two WRT300n Routers to Air-Stream Wireless which will allow us to conduct some grassroots testing on the 802.11n standard in the field, and explore these features under an Open Source firmware such as OpenWRT. Which was made possible through the support and encouragement of Jerry Clancy of ClearNet Communications

The 802.11n draft standard implemented in the WRT300N uses a technique called "MIMO" (multiple input, multiple output). MIMO technology capable of 300Mbps "By leveraging multipath reflections of a radio signal, and transmitting multiple signals in a single 20MHz radio channel, MIMO multiplies both data rates and reliable coverage area without using additional frequency spectrum, and without causing interference with other Wi-Fi devices and networks.

Equipment to get started

Typically what you will need is whats called "Stumbling Rig", which is comprising of the following:

Laptop
A portable computer, either laptop/notebook or PDA which should be able to house a PCMCIA wireless card. Ideally it should be able to run on battery power alone for some decent amount of time. If stumbling during the daylight hours it would be beneficial to have a screen that is visible outdoors.

Software
The common "stumbling software" used is Netstumbler for laptops with Windows operating systems or the PDA version Ministumbler for PDA devices. Netstumbler cycles through all possible wireless channels, probing for networks, and reports the SSID of any access point that responds to the probe. If supported by the chipset it will also report signal level, noise level and records the data for a graphical history display. Netstumbler also supports GPS devices for recording at what location it last received a signal for each network - not so useful for a site survey but good for other types of surveys such as wardriving. For more software information visit Software to get Started.

Wireless Card
The ideal wireless card for stumbling would be a PCMCIA card with external antenna connectors. The classic example of this is the Senao 2511CD+ EXT2. Other possible wireless cards are USB wireless adapters with external antenna connectors (useful for PDAs) or a miniPCI card inside the laptop with a special "pigtail" (see below) bringing the internal antenna connection to the outside. Some compact flash wireless cards may also have antenna connectors.
The card should also be supported by Netstumbler or Ministumbler. Various cards are supported to a different degree in Netstumbler, most will allow basic detecting of networks but may not report signal level. The Senao mentioned earlier uses the classic Prism chipset which is supported 100% by Netstumbler. This list is a compatability list for cards that have been reported to work with Netstumbler.

Pigtail
A pigtail, also known as a flylead, is a small piece of flexible coaxial cable. This will connect from the wireless card to the antenna or possibly to a piece of coaxial extension cable between the pigtail and the antenna. Typically you will need a N-type connector of the correct gender (see Common Wifi Connectors) to connect to the antenna or coax extension lead on one end of the pigtail and the appropriate connector to connect to your wireless card at the other end of the pigtail, typically an MMCX, MC or RP-SMA connector. Internal miniPCI cards use the u.FL type connector. All combinations are either readily available or can be made to suit. See your card manual for details.

Coax (1-5m)
Coax on a stumbling rig is a great idea as it allows the laptop to sit on the ground or in the lap of an observer. This allows you to have another hand free for stablising yourself on the roof/ladder/mast. It also makes it less likely to damage the fragile pigtail as there is more slack cable to work with. Essentially it is just a coaxial extension lead with an N-type connector on both ends, one end plugs into the antenna, the other plugs into the pigtail. Make sure the genders are all correct however it is always wise to have a few gender changing connectors around just in case. Good cable to use in this situation is LMR200.

Polarised Small antenna
A cantenna, yagi or a 15dBi parabolic grid antenna are best for doing a site survey (aka stumbling) as they can be held relatively easily in one hand and don't have much wind drag. If you can pick up signals at a reasonable level with a small antenna like, it is certain that moving to a larger antenna in a permanent setup is feasible. If you can only pick up a few ESSID beacons here and there from the low gain antenna you can try again with a higher gain antenna and verify if the signal is usable with more gain.

Controlled Test
Its worth testing your equipment with a AP that you know is in range at a range of around 20 metres to first see what a good signal is like, then cover the AP in a damp towel, in a plastic bag of course, to show what a poor signal is like. If you know your stumbling rig is working you can do a site survey, it is very unlikely that you will pick up no signals from APs. If you can not detect any APs then chances are your stumbling rig is not working properly.

Safety Equipment and Buddy
Even for simple acts such as holding a ladder or calling for tools it is a good idea to have a buddy present. Stumbling can be dangerous. Air-Stream will not accept liability for injuries sustained while undertaking wireless site surveys or installs, but reccomends using best practise which includes identifying hazards and risk minimisation. This includes wearing a harness, stumbling during dry and daylight conditions, always having at least two firm footholds and a hand hold and safe use of electrical equipment.

Air-Stream Stumbling Kit
If you don't have access to stumbling equipment, there is ready made stumbling kit available to any Air-Stream Member with everything you need to do a site survey.

If you have all of these things arranged in advance you will have a much more succesful site survey, best of luck!

Software to get started

Stumbling Software
Software that you use for a site survey is often refered to as a "stumbler" because you can stumble across wireless networks that you didnt know about before. It gives you an update about what the radio in your wireless network card receives through the antenna.

SSID
The information you receive is the following and ESSID which is a piece of text used to identify the wireless network. Airstream networks have an ESSID in teh following format "Air-Stream-Suburb-Name".

Signal, Noise and -dBm
Stumbling software also allow you to see the recieved signal strength intensity "RSSI" or signal strength. Along with the signal you will also see a certain amount of background noise. Ideally you want all signal and no noise. Or at least more signal than noise, hence we have a signal to noise ratio(SNR) we want a really high SNR. Both signal and noise are typically measured in -dBm which is a negative log scale.

What is a good signal?
The weakest signal is around -100dBm and the strongest signal is around -10dBm each 3dBm closer to zero is a doubling in signal. If you have a signal of -80 dBm to -1dBm you can get a decent 11Mbps link, with a signal of -90 dBm to -100 dBm your link will have problems and packet loss.
Also a SNR of at least 5 is required.

Scanning through channels
There are 13 channels on the 802.11b range of frequencies. A wireless card reads from the radio tuned into one channel at a time so it may take some time to scan through all channels, you can also lock a piece of stumbling software into one channel to focus on a particular AP on a given channel giving you better feedback rather than hoppign through all channels at once.

Netstumbler and Ministumbler http://netstumbler.org
And an excellent Windows application, with a full GUI, compatible with most wireless cards, including Prism chipsets (Senao) and Hermes chipsets (Orinocco, Lucent, Cabletron). The graphical feedback is easy to interpret at a glance.

Screenshots

Kismet
POSIX (Linux, BSD, Unix) based software. Good for identifying networks but difficult for determining signal strength, uses a scale of 0-255 from minimum to maximum and doesnt seen to isolate the signal to noise ratio per SSID. A small kismet drone or drones can be placed on a remote access point and relay packets to a kismet server. The kismet client then connects to the kismet server and displays the data as a text display. The client and server can be on the same physical system or on seperate systems connected by a network.

Screenshots

Wavemon
POSIX based software, uses the ncurses text package to display signal strength and other information graphically.

Screenshots

dstumbler
BSD

Screen shots

7 Channel LPT Port Controller

This circuit is drawn out in such a way that it can be easily assembled on vero-board. Not all 7 relays are required eg JF only uses only two, northfeild five and Carrick Hill will only use one.

The aim of this circuit is to enable a system script to reset or power cycle an ethernet AP's when they crash, which does happen from time to time. This is very usefull where access to a site is limited.

Download High res PDF

A Site Survey: Quality and Range of AP signal at your site

The only real way to tell if you can connect to Air-Stream or not is to get to the highest point on your property and do a site survey. The equipment required to do this is explained in Equipment to get Started which you may already have. If you are a member there is a stumbling kit* available for loan, or a generous member may be willing to help you out or lend equipment.

A site survey is the process of measuring which microwave signals emitted from Air-Stream Access Servers are accessible from your a handheld antenna and laptop. Also the strength and quality are assesed. Most of the time is is done on your roof. It doesn't take very much time if done properly and will answer the question "Can I join the Air-Stream Network?" once and for all.

*Note: The stumbling kit is available to Air-Stream members. Contact for more details.

Add an image to your post

Adding an image to your posts is easy.

First create a page and write your story, then scroll down to the File Attachment Link

Attach your image file.

Once the image file is attached, you can the place the image in your story with some html like I have done for this page.

Calculating the length of an Antenna

To calculate the wavelength of an Antenna the formula for Wavelength is the Speed of Light ~299,792,458 metres per second divided by the frequency in Hertz. However, because electricity travels slower through some materials than others, there is a need to reduce the speed of light by the Velocity of Propagation also commonly known as the Velocity Factor for example a piece of copper wire has a Velocity Factor of 0.951.

Consequently the formula of a full wave antenna at 2.447Ghz (Channel 8) using copper wire is:

(299,792,458 x 0.951) / 2,4470,000,000 = 112mm

A Half Wave antenna would then be 56mm and a Quarter Wave antenna would be 28mm

Please note: This is only a guide to home made antenna building, when looking around the Internet you'll find many variations to this calculation due of a number of reasons ranging from rounding down/up or ways to match the impedance of the antenna with the feed line.

For example feed lines for Transmitters and Transceivers are 50 Ohms so too Wireless LAN equipment. However a half wave dipole is 72 Ohms and a quarter mono pole is 30 Ohms but for maximum efficiency both feed line and antenna must be the same impedance. Consequently there are many tricks employed to achieve a match and no doubt antenna design is a very complex area, but you'll be surprised of what can be done with a little experimentation, specially as the equipment used in Wireless LAN is very low-powered and therefor the risks of equipment damage and interference is minimal and so well worth having a go.

Changing ACK timeout on various OSes

Throughput can be improved over long distance links by changing the ACK/CTS timeouts and Slottime, see http://www.air-stream.org/ACK_Timeouts

RouterOS

The ACK Timeout option is found in the Winbox GUI under the "Advanced" tab for the interface settings - make sure "Advanced Mode" is clicked on. RouterOS has a feature which dynamically calculates the ACK Timeout, this is the default option and seems to work well for most installations. For manual setting of the ACK Timeout just type in the number in microseconds and click Apply.

Atheros cards using athctrl

athctrl is a small utility for Linux that changes the ACK Timeout, CTS Timeout and Slottime based on the maximum distance you specify, in meters. It's usage is:

athctrl [-h] [-i device] [-d distance]

The maximum acktimeout/ctstimeout possible on atheros based cards is currently 409 µs, working out to a maximum distance of about 53-57 km.

Examples

athctrl -d 1000

Set maximum distance of 1000m for wifi0.

athctrl -i wifi1 -d 5000

Set maximum distance of 5000m for wifi1.

OpenWrt + Madwifi

The physical layer parameters are stored in /proc/sys/dev/wifiX

To view a parameter, such as acktimeout on wifi0

OpenWrt:~# sysctl dev.wifi0.acktimeout
dev.wifi0.acktimeout = 22

Example

I want to set up my 802.11a card, wifi0, for an 8 km link.The default slottime is 9 and the default acktimeout is 22 as discovered from the above command.

I must add 1 to slottime and 2 to acktimeout for every 300 meters over the initial 300. This means I need to add an extra (8000 - 300) / 300 = 25.7 to slottime. I will round up to 26 to be safe. So my slottime will be 9 + 26 = 35, and my acktimeout and ctstimeout will both be 22 + 26 * 2 = 74.

This can be manually done as follows

OpenWrt:~# sysctl -w dev.wifi0.acktimeout=74
dev.wifi0.acktimeout = 74
OpenWrt:~# sysctl -w dev.wifi0.ctstimeout=74
dev.wifi0.ctstimeout = 74
OpenWrt:~# sysctl -w dev.wifi0.slottime=35
dev.wifi0.slottime = 35

To make this permanent on bootup, one would add the following lines to /etc/sysctl.conf

dev.wifi0.ctstimeout=74
dev.wifi0.acktimeout=74
dev.wifi0.slottime=35

BSD

sysctl can be used in BSD based operating systems to access and modify the parameters, the format is similar. 

Example

For example on interface wl1:

~# sysctl -w dev.wl.1.acktimeout=74
dev.wl.1.acktimeout: 22 -> 74
~# sysctl -w dev.wl.1.ctstimeout=74
dev.wl.1.ctstimeout: 22 -> 74
~# sysctl -w dev.wl.1.slottime=35
dev.wl.1.slottime: 9 -> 35

To make it permanent on bootup, one would add the following line to /etc/sysctl.conf

dev.wl.1.acktimeout=74
dev.wl.1.ctstimeout=74
dev.wl.1.slottime=35

OpenWrt Whiterussian + Broadcom

The dctrl utility by nbd or an nvram setting in Whiterussian can be used to specify the maximum distance between stations. dctrl usage is:

dctrl [max distance in meters]

In Whiterussian RC5 or higher, the nvram setting wl0_distance can control the maximum distance, specified in meters. A small utility called sdist, attached to this page, can be used to verify that the correct registers have been changed. Remember to run /sbin/wifi to reload wifi settings after changing nvram.

Example

Checking initial values using sdist, then changing wl0_distance to 20kms, reloading wifi settings. Checking that the registers in the wifi card actually changed, then committing the nvram so the wl0_distance setting persists on reboot.

OpenWrt:~# ./sdist
shm: 0x9
reg 684: 0x207
OpenWrt:~# nvram set wl0_distance=20000
OpenWrt:~# /sbin/wifi
OpenWrt:~# ./sdist
shm: 0x8f
reg 684: 0x28d
OpenWrt:~# nvram commit

HostAP + Prism ?

Do we care?

Note about Atheros: If using 802.11g it would be a good idea to lock the station into 11g, to prevent slottime resetting if a 11b client tries to connect. This is accessed in Linux/Madwifi through iwpriv <interface> mode 11g and in BSD through ifconfig <interface> mode 11g

Circular Wave Guide Antenna for 5.8Ghz 802.11a

Inside Diamter of Tube = 35.8 (Type 40 Copper Water Pipe)

Operating Frequency = 5800MHz
Lower Cut Off Frequency = 4908Mhz
Upper Cut-Off Frequency = 6410Mhz
Total Length = 69.5mm
Feed distance from back = 22mm
Feed Probe Length = 11.5mm
Expected Gain 8dbi

Coaxial Cables

	Any 50 Ohm coax will work for attaching external antennas on wireless network equipment for 2.4Ghz and 5,8Ghz equipment. However there are a number of factors that affect performance due to rf leakage and attenuation due to materials and shielding used by manufacturers. These factors become more important the higher the frequency and lower the power level used. Both apply to wireless network equipment and so it is important to use higher quality coaxial cables or keep lengths to a minimum. This translates into a 50 Ohm coax cable with a non-foam dielectric eg Teflon, PTFE or polyethylene and double screened shielding with less than 1.5db per metre at a frequency greater than 2 GHz. But remember a loss of 3db means a 50% reduction in power...
Examples are: Semi-Rigid RG402U or RG405U suitable for hard wiring and fixed pigtails LMR195 suitable for making Pigtails max 3 Meters CFD200 or CNT200 suitable for making Pigtails max 5 Meters CNT400, CFD400 or LMR400 suitable for Antenna runs up to 10 Meters LDF4-50A (Heliax) suitable for Antenna runs up to 20 Meters
The impedance of a coaxial cable that has a round center conductor and a round outer conductor is as follows: Zo = 138 Log (D/d) Log is always to base 10, (ln is natural log). Zo is the surge impedance, generally 50 ohms, D = inside diameter of the outer conductor, d = outside diameter of the inter conductor. Any dielectric other than air requires that the constant 138 be modified by dividing it by the square root of the dielectric constant of the insulating material.

Didz Senao 2511CD PLUS EXT2

I keep repairing my pigtail and this time its on for good. As you can see I allready have quite a bit of heatshrink on it to stiffen it. on the N-male side you can see a small bulge from when i fixed it up with solder in the past

After ripping out the main connector when tring to take out one of my pigtails I was left with one connector. Normally you can use it fine and the drivers provided say that its getting a signal but netstumbler is completly blind.

I had been soldering the pigtail onto the card but would break soon after usally when really needed like stumbling on someones roof with no plan b.

It took me a few months before I had the corage to rip the other connector and decide to make that damn coax secure by runing it though the card itself filing up the rest of the card with glue

Solding the coax onto the small tracks of the card was not hard and the coax takes the solder quite well. Someone with a shakey hand cannot do something like this, were talking millimetres here!

I had to take off the clear casing that let the LED shine though and melt away some of the inside of the casing to make the coax fit though. I went a little too far and made two holes but ah well. Those holes wont be a problem when coax and glue will be there instead.

Results are that it works! after all the work I have put into the many repair jobs im still able to pickup access points with results as if it was brand new. The soldering I have done doesnt seem to have affected its performance if at all.

Good solder joins do pay off.

Dlink DCF-660W External Antenna Modification

Nevertheless this modification does allow the attachment of a standard 2dbi or 5dbi rubber ducky antenna, which many will have floating around the shed.

	Stage 1. Remove plastic cover, notice the metal strip, this is the internal antenna.
	Stage 2. First cut the pin leaving as much length as possible. Then bend the metal strip back and forwards until the strip brakes off.
	Stage 3. A right angle reverse SMA PCB plug can be soldered directly to the remaining metal strip. Ensure the plug is centred and alinged with the cut pin.
	Stage 4. Solder the cup pin to the centre pin of the reverse SMA Plug. Ensure that not to much heat is used as the pin may move during soldering.
	Stage 5. Place the removed cover back and mark out a slot to be cut for the connector.
	Stage 6. As noticed here the cover will not fit directly back due to the hight of the reverse SMA plug.
	Stage 7. I find the best way to hold everthing in place is to fit heat shrink, the hot glue sealed heatshink offers the best results for strength. But normal heat shrink can be used.

Equipment needed to connect into the network.

There are many different ways to connect to a wireless network over distance and even more choices of equipment. The following are three typical examples of what maybe used to connect an Access Point over 5kms in the right conditions such as: Line of Sight (LOS) , Polarization and Fresnel Zone Clearance.

Image A uses a router which can be flashed with openWRT and although this requires some coding skills it allows for the implementation of many network functions such as firewalls, routing rules and subnet allocations.

Image B uses a standard Ethernet Bridge and would represent the cheapest setup for wireless users. The limitations are that only one IP is usable and therefore will require an additional server or router if you wish to deploy subnet IP ranges over your local network.

Image C represents simplest form of set-up where the wireless device (eg: CM9) is installed into a computer or server. This offers a great number of advantages as well as its clear simplicity. The disadvantages are that the computer needs to be located closer to the Antenna, or is used with expensive low-loss coax cable which may reduce link performance.

Information on Power Over Ethernet (PoE) can be found here: http://www.air-stream.org.au/poe

Folded Dipoles

The drawing here shows the essential elements of a folded dipole and consists of two parallel elements having a constant spacing S with each element having a certain diameter, d1 and d2.

The ends of the parallel elements are connected to form a continuous loop and the feedpoint is at the center of the element having the diameter d1.

Consequently, in this calculation we use the value of single-wire dipole, the feedpoint impedance will be transformed upward by the ratio R according the equation seen below.

In free space the impedance, of a resonant 1/2 wave dipole antenna with a centre feed is aproximately 72 Ohms. Hence, a folded dipole using equal diameters for both elements will have a ratio of 4 and therefore an impedance of about 288 Ohms.

Image Assist

A new feature has been added to the Air-Stream Website called Image Assist which allows members to easily upload and insert images inline into your website blogs and comments. It automatically generates an "Add image" link under the "Body" field when creating content.

By clicking the link it opens an image browser, displaying all the images you have previously uploaded via the Images Module.

Parallel Port (LPT) Remote Control

The aim of this circuit is to enable a system script to reset or power cycle an AP or router when they crash or lock, which does happen from time to time. This is very usefully where access to a site is limited.

Nevertheless the same circuit could be used for any remote control project where you need to switch on and off a device using a computer.

The following circuits are drawn out in such a way that it can be easily assembled on vero-board.

The design allows from 1 to 7 relays to be used.

The download link for two different versions are as follows:

One Relay: http://www.air-stream.org/files/1_channel_LPT_0.pdf
Seven Relays: http://www.air-stream.org/files/7_channel_LPT.pdf

Power Over Ethernet (PoE) Building

An Ethernet Wireless Device is a very practical approach, mainly because they can be located near the Antenna in a waterproof box and the Ethernet cable can be run a fair distance away up to 300 metres in some cases.

Ethernet connections require only two pairs of cable TX & RX, but in a standard Cat5e cable there are 4 pairs. This allows for the spare pair to used for injection of power over the Ethernet. Called Power Over Ethernet (PoE) it is common practice to use the Blue and Brown pairs for this purpose.

An issue may occur on long Ethernet runs, when this method is used in combination with some Wireless Devices that require a low voltage (5V) or a regulated power.

This is because there will be a voltage drop over the length of cable due to I²R losses. In these circumstances a higher voltage is injected into the cable and a voltage regulator is installed with the Wireless Device to drop the voltage down again to the desired voltage.

An example of a such a regulator can be found here: http://www.air-stream.org/LM2576

A useful list of PoE industry standards can be found here: http://www.air-stream.org.au/poe_standards

Power Over Ethernet (PoE) Standards

STANDARD	Source Voltage	1	2	3	4	5	6	7	8	REMARKS
IEEE 802.3af using data pairs	48 V DC, protected	RX, DC+	RX, DC+	TX, DC-	spare	spare	TX, DC-	spare	spare	Industry Standard for embedded PoE
IEEE 802.3af using spare pairs	48 V DC, protected	RX	RX	TX	DC+	DC+	TX	DC-	DC-	Industry Standard for embedded PoE
Intel, Symbol, Orinoco	Usually 12 or 24 V DC	RX	RX	TX	DC+	DC+	TX	DC-	DC-	Most Brands of PoE
Cisco (OLD old standard)	48 V DC	RX	RX	TX	DC-	DC-	TX	DC+	DC+	Older Cisco polarity is REVERSED
Cisco (NEW old standard)	48 V DC	RX	RX	TX	DC+	DC+	TX	DC-	DC-	New Cisco is IEEE compliant

Run Senao PCMCIA Wireless Card in Windows

The manual provided is pretty straight forward but both the manual and drivers provided were written before Windows XP Service Pack 2 so here is how to get the drivers working.

Service Pack 1

Do as the drivers say and disable windows thing by un checking it in the properties of the wireless card.

Service Pack 2

Run Computer Management (Windows key + R, type in compmgmt.msc and click OK)

Select 'Services and Applications'
Below that click 'Services'
On the right hand side look for 'Wireless Zero Configuration'
Double click it

Select the startup type as 'Disabled'
Click OK.

This can be done before or after the drivers are installed it should not matter. If Wireless Zero Configuration is running the drivers provided will always say 'data error, check WEP settings' in the tool tip when hovering over the taskbar when you associate to any access point.

Nothing else should be needed, the drivers and NetStumbler should work normally.

Simple 3 Amp Step Down Switchmode Regulator

Although this example is 5V, there are also 3.3V, 12V, 15V, and adjustable output versions (see attached datasheet).

Except for the Adjustable output version the same layout can be used for each.

Note: Pin 5 (which is grounded below) can also be used to switch the external loads on/off via a logic input e.g. 0v or 5V, for example an LPT port.

You must be logged-on to access the datasheet.

UltraWAP power over ethernet mods

More power over ethernet mods. This one for an UltraWAP.

Sweeping the sky

Polarisation

Antennas on APs generally cover a broad spread of the horizon whereas client antennas are usually directional, focusing on a particular region in order to get more signal and less noise. Another strategy employed by antennas to reduce noise is polarisation. This removes the microwaves oscillating in any other direction apart from the polarisation of the antenna. For large range antennas there are two or three types: Omni Linear Colinear which are vertically polarised and Waveguides which are horizontally polarised. There are also sector panel antennas which can be either.
When you are doing a signal survey it is important to know the polarisation of the AP you are surveying. For a general survey, you will need to try both polarisations.

Horizontally Polarised

AP: Waveguides
Survey antenna: grid wires mostly going left to right

Vertically Polarised

AP: Omni (linear colinear omni)
Survey Antenna: Grid wires mostly going up and down

Know your antenna

If you can, go to a location with a known AP in visual contact and try seeing what you can do with your antenna to get the optimal signal. This will let you know if you antenna has any quirks and also allow you to know how your stumbling software works.

Scanning for APs

When sweeping the sky, take a good 5-10 minutes to sweep slowly around the horizon. You need to wait for the AP to send out a beacon and you need to wait for your wireless card to go through the 13 channels. Too
hasty is wastely. Take note of the general directions where APs are found and then focus in on these directions once you have found which are the most promising APs.
Once you have done one polarisation, repeat with the other polaristion. On horizontal polarisation you will pick up the wave guides and on the vertical you will pick up omnis.

Fine tuning the signal

This is only really essential when installing equipment, but while the gear is out you may as well try this as well. Find the direction with the strongest signal, move in small increments until the signal falls off. Then sweep back in even smaller increments, zig zagging across the signal until there is no more improvement. Try raising and lowering on the horizon as well.

Save you results

Once you have finished your site survey, remember to always save your results. They are of interest to other people who are in the same area and to AP owners who like to know how far their signal is spreading.
This may inspire people to put up gear at your site to be a relay point.

Stumbling Kit

The Air-Stream Stumbling kit is available to Air-Stream members to use for site surveys. The kit is maintained by Shawn and is available for loan to members at his discretion.

The kit includes everything needed to do a basic site survey:

• Handheld PDA with wireless card and stumbling software
• 14 dBi "Yagi" style antenna
• Appropriate pigtail, coax leads and connectors
• PDA docking bay, AC adapter and car charger

Bookings can be made by contacting the committee (committee at air-stream dot org.) The only thing to remember is that you will be responsible for lost or damaged equipment.

The antenna is a Yagi style antenna which can be used in vertical or horizontal polarisation and is simply pointed in the direction you wish to stumble. Other antennas can be used with the PDA, however your antenna must have either a RP-SMA male or N female connector to connect to the pigtail in this kit.

If you can stumble a site with this kit, it is fairly certain that a permanent connection could be made with a good antenna and wireless equipment.

For more information about "stumbling" or site surveys visit Equipment to get started and Software to get started

Air-Stream Wireless Membership Database

The members database is so much bigger with Node creation, IP allocation, mapping modules, terrain, satellite and LOS signal propagation... Exclusive to Air-Stream members only the new system designed by Troy Vodopivec combines membership information. LDAP and our IP Database with the power of Google's mapping API, signal propagation prediction to offer members a carrier class system that rivals any other community wireless network in Australia. Please note, this is continually being improved and so subject to conditions, please support this excellent project with constructive bug reports.

Amateur Radio

The following pages include information about specific Amateur Radio content that is accessible or could be easily accessible on the Air-Stream network. If you are a member and are a Amateur Radio operator please add your services here. Affiliated clubs may also add information about services available, please contact the committee for details.

Please note:Members shall ensure all network servers with content not intended for non-licensed Amateur Radio operators only, are secured appropriately.

Interlinking of amateur stations using Air-Stream

The interlinking of amateur stations using the Air-Stream Wireless Network is not prohibited by section 11 of the Amateur Licence Determination provided non-amateurs cannot gain access to the amateur stations involved. When this requirement is satisfied, the network connection is equivalent to a private line. Users must hold a current amateur licence and communications must be isolated from the general public and other members through the use of software, hardware and operational measures.

Some software that can be used include:
* http://www.echolink.org/
* http://www.irlp.net/

DNS

DNS (Domain Name Service) is the process by which names are translated into IP numbers, and vice versa.

DNS servers

• 10.96.0.10 - Anycast Resolver

For DNS enquires contact the committee

Note: DNS systems are currently being upgraded, please check your member email for updates.

Email

Air-Stream Members receive an email account when they join, which is to be used for all formal correspondence within the group. The username you provided on your application form is used to set up your account, full details are emailed to your alternate address when it is created.

To reset your email password, just use the Member Control Panel.

Secure Mail Access

Air-Stream mail services are configured to use TLS/SSL (Secure Sockets Layer) connections. This provides a secure medium for your mail application to communicate with the server, and is required for access via the wireless network.

All secure Air-Stream services use certificates that are signed by the "Air-Stream Certificate Authority". To remove the warning pop up you receive in your browser/email client, you need to add the Air-Stream Root Certificate to your software's keychain. This will allow your software to correctly verify any certificates signed by Air-Stream.

See Securing Air-Stream Services with TLS/SSL for more information.

SPAM filtering

Please see SPAM Filtering Usage page for more information.

Web Mail

Secure mail services can be accessed from anywhere via an Internet web browser, by visiting this address: https://mail.air-stream.org.

* If you are having difficulty with the configuration of your favorite mail application, try using the Web Mail as fall back for support, or to contact the committee.

Retrieving mail via IMAP

When using IMAP protocol your email client connects to the server and views messages directly, downloading them only if required. Messages are usually left on the server until deleted at a later stage. IMAP is used by the WebMail client.

Incoming IMAP Server: mail.air-stream.org
Username: your Air-Stream username
Password: your Air-Stream password
IMAP Prefix: none

* Service available on insecure port 143 from the Internet or secure port 993 from the Internet or wireless network.
* Clients connecting from the wireless network must enable 'SSL' in their mail clients.

Retrieving mail via POP3

POP3 is the most common external mail retrieval method. The client checks for new messages on the server and downloads them, after which they are deleted from the server. Optionally they can be left on the server for a period before deletion (configured in your email client).

Incoming POP Server: mail.air-stream.org
Username: your Air-Stream username
Password: your Air-Stream password

* Service available on insecure port 110 from the Internet or secure port 995 from the Internet or wireless network.
* Clients connecting from the wireless network must enable 'SSL' and use port 995.

See this page for instructions on how to do this in most common email clients.

Sending mail via SMTP

Air-Stream's mail server uses Authenticated SMTP with TLS encryption.

What this means is that in order to relay mail through the Air-Stream server (send to non Air-Stream accounts) you must configure your mail application to login with your username and password first. To ensure these credentials are kept safe, this must be done over a secure channel (using TLS/SSL). Most email clients support this feature, by entering your username and password when specifying the SMTP server. There is usually also a tick box selection for the use of TLS or SSL.

Outgoing SMTP Server: mail.air-stream.org
Username: your Air-Stream username
Password: your Air-Stream password

* Relaying is only available to authenticated clients.
* Relaying is available using TLS on port 25 from the Internet or secure port 465 from the Internet or wireless network.
* Clients connecting from the wireless network must enable 'SSL' and use port 465.

If you have any comments or questions please contact the committee

X-DSPAM-Result: Innocent
X-DSPAM-Processed: Tue Aug 18 18:21:18 2009
X-DSPAM-Confidence: 0.9899
X-DSPAM-Probability: 0.0000
X-DSPAM-Signature: 4a8a6b86266376863418247

File Transfering (FTP)

FTP (File Transfer Protocol) is generally used for file sharing and there are many FTP servers on the network setup by member for use by other members.

It is also important to note that all Core network routers do not offer FTP services other than for file transfer speed testing.

If you have an FTP server and wish to share it with other please add your IP or URL as a comment here.

However members who do provide FTP servers should be aware that they are solely responsible for its content, member’s should use their discretion and make appropriate decisions about what content is made available freely; who can contribute content and access rights you should apply.

Before accessing or copying files to and from a FTP server please do so responsibly and take the same precautions that you would when using Internet.

Games

The following games servers are available over the wireless network:

• Call of Duty 2 [10.108.1.75]
  • Quake 3 CPMA & TC
  • Unreal Tournament 2004
  • Halo
  • Need For Speed Underground
  • Tradewars
  • Live For Speed - 203.27.114.2 (Area51 LFS Server) Join

    You need LFS Join for the in browser connect to work.

  • Starcraft, Warcraft III, Diablo 2 LOD 1.10 closed realm via battlenet (PvPGN Bnetd) [10.108.3.10] (ftp to 10.108.3.10 for support files)

  Sometimes users setup temporary servers for a quick game of their choice, Most decide on the IRC channel

  
  

Internet Access

"Does Air-Stream Wireless provide internet?"

This is a question that is often asked and the short answer is "No But" this is because anything can be shared over a distributed WAN , including Internet access.

Networks like Air-Stream Wireless are not about service provisioning but rather physical access and do not hold the necessary licenses to permit the sale of services including internet access.

Although there are a number of multihomed and internet services available on the network it is important to note that membership fees are not a fee-for-service and that any service that is available has been volunteered freely by a member or another participating group.

But simply individual members or participating community groups may use the network to share their Internet access with others, provided there are no financial rewards involved eg: offered freely without condition.

IP Telephony (VoIP)

Voice over Internet Protocol (VoIP)

Make free phone calls between members without time limits, over the Air-Stream network. Sorry no public phone system access.

Contact committee to setup an account.

VoIP Software

There is free sip phone software and many hardware sip phones on the market.

Links to software see www.voip-info.org/

The most popular used on the Air-Stream network is X-Lite
There is also SJphone

VoIP Server

The VoIP server is located at Melrose Park.

IP: 10.114.2.4
Port: 5060

Set these details on your phone or program including your username and password. account details are given to you when your VoIP account is made.

Air-Stream is operating Asterisk server and is available for all members to use. Asterisk is a complete PBX in software. It runs on BSD/Linux and provides all of the features you would expect from a PBX and more.

Asterisk does voice over IP in three protocols, and can interoperate with almost all standards-based telephony equipment using relatively inexpensive hardware.

For more information about Asterisk visit www.asterisk.org

IRC Servers

IRC enables users to discuss issues, make plans, help out others with their wireless projects, chat instantly with others, etc.

Although not the official voice of Air-Stream and now strictly Air-Stream members only, it can still be a useful source of information.
To use this service you will need your Air-Stream members login.

How to connect

There are multiple IRC servers linked together, these can be accessed via the Air-Stream wireless network and the internet using a IRC client.

Air-Stream IRC address:

irc://irc.air-stream.wan:+7000

irc.air-stream.org - Internet

10.108.1.73 - Valley View
10.114.2.29 - Melrose Park
coming soon - Mawson Centre

*Note port 7000 SSL connections only

Authentication

Air-Streams IRC Servers now require member login to authenticate and use the IRC network.
To authenticate you are required to use your Air-Stream username as the "Identd User ID" or "Username" and your password must be entered in the IRC Server "Password" field.

For more detailed instructions please see the how to pages provided by members below.

SSL

More info on SSL with mIRC: http://www.mirc.co.uk/ssl.html
OpenSSL project web page: http://www.openssl.org/

Terms of Use

Due to the nature of IRC, moderation of content is difficult to control and thus the actions of users on the IRC server remain the responsibility of themselves, not Air-Stream Wireless Inc. Server operators, channel operators or channel half operators to reprimand disruptive users. Administrators of this server reserve the right to intercept and monitor any network traffic in response to suspected denial of service attack or other technical misuse. By connecting to these IRC servers you understand and agree to these terms and conditions.

Jabber Chat Service

The Air-Stream Wireless Jabber service provides a feature rich environment for member interaction utilising the Jabber protocol and is available both on the Air-Stream wireless network and the Internet.

Jabber is a collection of open, XML-based protocols for instant messaging and presence information. Jabber-based software is deployed on thousands of servers across the Internet and is used by over ten million people worldwide.

Getting online

The Jabber server will be available to Air-Stream Members only and utilises member LDAP for authentication.

The service can be accessed over the Internet at chat.air-stream.org or over wireless at 10.114.2.2

Client applications are available for most OS platforms see their website www.jabber.org/ for details.

Adium for OSX

Note: This guide applies to people using the Mac OS X operating system.

1. Download latest Adium

• Visit the Adium website to grab the latest .dmg (disk image) of the software: http://www.adiumx.com.

2. Install to Applications folder

• Once the disk image has been downloaded, it may or may not automatically be 'mounted' by your system.
• If it's not already mounted (identified by a removable disk icon in the finder), just double click on the .dmg file you downloaded to do so.
• Install Adium by dragging the Adium icon from the mounted disk image, into your Applications folder.
• You may be prompted to enter an administrator's password at this time.
• Once this process is complete you can eject and throw away the disk image.

Note: you can install Adium anywhere you like, it doesn't have to be the Applications folder.

3. Launch Adium

• You may like to create a shortcut to Adium by dragging its icon from where you installed it, onto the OSX 'dock'.
• Click the Adium icon to launch the program.

Adium's preferences panel should appear.

4. Configure your account

From the + menu, select 'Jabber' to setup a Jabber account.






Enter the Account settings as below.

• Jabber ID: your Air-Stream LDAP username.
• Password: your Air-Stream LDAP password.

Enter Personal settings as below.

• Choose an 'avatar' icon from a local image file on your hard drive.
• Alias: Choose an alias that suits your needs.

Enter the server information settings as below.

• Connect Server: chat.air-stream.org.au
• Resource: Adium.
• Port: 5222.
• Security: Tick 'Use TLS encryption (if possible)'.
• Press the OK button when done.

You should now try to connect by checking the checkbox on the left.

When successful, your roster will be populated with Air-Stream members.

Spark for Windows and OSX

1. Download latest Spark

Spark is a barebones Jabber client made by Jive Software. Its avaliable for Mac OS X, Linux and Unix, and Windows from http://www.jivesoftware.org.

2. Configure Spark for Air-Stream

Once downloaded, the configuration process should be similar on all operating systems. You will be presented with the following screens the first time you run Spark.

Edit the appropriate information, as below.

• Username: Your Air-Stream LDAP username.
• Password: Your Air-Stream LDAP password.
• Server: chat.air-stream.org
• Tick save password, and choose Auto Login to make life a bit easier.
• Click 'Login' to connect.

Once connected successfully, you should see the Air-Stream roster

MRTG - The Multi Router Traffic Grapher

The Multi Router Traffic Grapher (MRTG) is a tool to monitor the traffic load on network links. MRTG generates HTML pages containing PNG images which provide a LIVE visual representation of this traffic.

Check 10.114.2.2/mrtg/ to see what it does on the wirless network (note not all routers are currently listed)

Network Time Protocol (NTP)

What is NTP?

NTP stands for Network Time Protocol, and it is an Internet protocol used to synchronize the clocks of computers to some time reference.

Servers

ntp.air-stream.wan [10.114.2.3] at Melrose Park
[10.107.0.2] at Uleybury

How To Use

Windows XP

- Access your 'Date and Time Properties' and select the 'Internet Time' tab.
- Type in your preferred address and apply.
- You can also update instantly by clicking the 'Update Now' button.

Note: sometimes it may not work the first time or an error might come up but it should eventualy synchronize.

Radio Astronomy

The following frequencies are generally accepted spectral regions for radio astronomical observations in radio astronomy. There are others frequencies, but I've chosen to list the regions that maybe most accessible by an amateur radio astronomer.

• 13.360 – 13.410 Mhz
• 25.550 – 25.670 Mhz
• 37.5 – 38.25 Mhz
• 73 – 74.6 Mhz
• 150.05 – 153 Mhz
• 322 – 328.6 Mhz
• 406.1 – 410 Mhz
• 608 – 614 Mhz
• 1.4 – 1.427 Ghz
• 1.6106 – 1.6138 Ghz
• 1.66 – 1.67 Ghz
• 2.655 – 2.700 Ghz
• 4.8 – 5 Ghz
• 10.6 – 10.7 Ghz

The above bands are based on Australian Radiofrequency Spectrum Plan - Radiocommunications Act 1992

The lower segments are used for solar and Jupiter observations; the 73, 150 and 406 MHz segments are quite popular for pulsar, and the 1.4 Ghz band is used for hydrogen line measurements, which seems to be the most popular with many amateur radio astronomer. Aslo made even more so by the Seti League Program

In very simple terms the equipment to build a Radio Telescope are:

• A sensitive radio which can receive one of the above frequencies.
• A radio with "No" AGC (automatic gain control) or has the ability to turn it off.
• A high gain low noise pre-amp and a directional antenna which can be pointed at the sky.
• A Data Logger to record total signal strength of the radio over a period of time

The signal strength of the radio is recorded over a period of time, signal levels will increase and decrease as a radio emitting object passes across the sky. Over number of days it is possible isolate radio astronomical observations from ground and satellite interference.

Radio Astronomy links:
Radio astronomy - Wikipedia, the free encyclopedia
Hydrogen line - Wikipedia, the free encyclopedia
The Parkes Observatory
Amateur radio astronomy with SIMPLE 20 MHz arrays

For more information on the history of TLS/SSL, see this article on Wikipedia.

Air-Stream Root Certificate

All secure Air-Stream services use certificates that are signed by the "Air-Stream Certificate Authority". This is a special private key that is kept in a secure location with only physical access allowed to it. The Root Certificate is the special public key clients can use to verify the identity of any server using an "official" signed certificate.

For more information on what a Root Certificate is, see this article on Wikipedia.

To remove the warning pop up you receive in your browser/email client, you need to add the Air-Stream Root Certificate to your software's keychain. This will allow your software to correctly verify any certificates signed by Air-Stream.

Download the Air-Stream Root Certificate here

We are looking for volunteers to create guides for adding the root certificate to commonly used applications. If you have successfully done so and would like to create a short how-to with a few images, please forward it to the committee for inclusion in this document.

Obtaining a Signed Certificate

If you are providing a service on the Air-Stream network and would like an "official" signed certificate to use, please forward an email to hat _at_ air-stream dot org with full details of your service, its IP address, hostname, purpose, etc.

Show LOS Coverage

Network administration have updating the 'line of sight' data for all nodes in the Air-Stream node database to add a feature which allows you to flag a node as 'needing LOS update'. The processing will then be done periodically in the background, to keep this data up-to-date!

You can view the line of sight plot for a node by clicking it and selecting 'Show LOS Coverage' from the popup window. Please note that this plot uses digital elevation data and thus only accounts for land mass, not trees, buildings, or other obstructions.

Streaming Radio

About Air-Stream Streaming Radio

These radio stations are operated by Air-Stream members, utilizing their and other Air-Stream members time and resources.
Uptime of these radio stations are not guaranteed due to the volunteer nature of Air-Stream.

Anyone is welcome to grow the list of available stations on the Air-Stream network.

How do I play these streams?

To be able to listen to these radio stations, you require a program on your computer which is capable of playing streaming MP3, OGG or Shoutcast streams. The following programs support the playback of these streams:

Apple iTunes Mac OS X and Windows 2000/XP
Nullsoft Winamp Windows 9x/NT/2000/XP
XMMS Unix/Linux with X11

Radio Station List

If you have one of the above programs, clicking on a play link below for a selected station, should begin playing the stream.

*Only available on Air-Stream Wireless Network

Air-Stream Members Streaming Radio - Station List

Web Pages (HTTP)

Web pages are on the Air-Stream network and are run by HTTP (hyper text transfer protocol) servers. Some core routers have a HTTP server while users can setup a HTTP server and display web pages if they want too.

Due to changes in DNS and test DNS servers links here may not work. IPs will be listed as much as possible.

Services

• Air-Stream Website is available from the Internet and the Air-Stream network
  http://www.air-stream.org.au/
• Air-Stream IRC irc://irc.air-stream.wan:+7000
  Valey View: 10.108.1.75
  Para Hills: 10.108.0.161
  Uleybury: 10.107.0.2
  Mawson Centre: 10.106.0.66
• Air-Stream Seaton IRC irc://10.120.128.65:6667
• Air-Stream FTP Crawler: HTTP
• Air-Stream Members: Local and Internet
• Air-Stream Directory: HTTP
• Air-Stream Node Runner: HTTP - guest/guest
• Air-Stream Jabber: chat.air-stream.org.au
• Air-Stream Map: Local and Internet
• Air-Stream NTP: ntp.air-stream.wan [10.114.2.3]
• Air-Stream Portal: HTTP
• Air-Stream Radio: Valley View - HTTP and Station List
• Air-Stream Webmail: https://150.101.63.178/
  Local: normal and secure.
  Internet: normal and secure.
• Air-Stream VoIP: HTTP
• Air-Stream DNSomatic:
• Meekys: SmokePing: HTTP Internet
• Samiam: MTRG Scanner

Core Servers

Most core routers running HTTP have a basic page where you can download a speed test file.

• Mawson Lakes: HTTP
• Melrose Park:
• Seaton: IRC
• Para Hills: HTTP
• Pasadena: HTTP FTP
• Ridleyton: HTTP
• Uleybury: 10.107.0.2 NTP: 10.107.0.2
• Valley View: HTTP

Client Servers

Clients may choose any type of service they would like to run.

• Betsuin: Betsuin WiFi
• Bishop Family HTTP
• Didz: HTTP .67 HTTP .68 FTP .67 FTP .68
• Drift: http://10.114.0.33 -SAGRN Pager Feed - Scanner Audio Feed FTP
• DrGeforce3: HTTP FTP
• Duncan: HTTP FTP
• Meekys: HTTP - Air-Stream Map - Statistics - SmokePing - FTP
• Hat: HTTP
• Robert: The Shed HTTP
• Samiam: HTTP - Scanner - FTP: Lenny Cyri Trudy MTRG: Local and Internet
• Seabird: HTTP FTP
• Shadey: HTTP
• Spinner: HTTP FTP