F.A.Q
WiFi
WiFi standards 802.11b, 802.11g and 802.11a ?
The main differences are in distance compatibility and speed.
The bottom line 802.11b will give you the best connection most of the time and the longest distance. if your application is internet access it will provide many time the throughput of the fastest internet connections. Although 802.11g products provide more bandwidth they are much more susceptible to noise. 802.11a products have the same speed as g but have shorter range while they provide a more reliable connection.
802.11b
Speed wise 802.11b provides up to 11mpbs raw throughput or about 5.5mbps after protocol overhead. if your application is Internet access then 802.11b standard has many times the bandwidth of your internet connection be it Cable, DSL or a full T1. 802.11b also has enough bandwidth to stream high quality divx video to a set top box this requires about 1.5mbps sustained throughput. For distance 802.11b is the clear winner because of a couple of factors one being transmit power of up to 200mW the other is low protocol overhead of CCK. You can expect up to 800 feet or 1200 meters from a 200mW 802.11b card. For compatibility 802.11b compatible products with work with the greatest number of installed networks including all public Hot Spots. 802.11b is also backward compatible with 802.11g products because they both use the 2.5ghz ISM frequency band.
802.11g
802.11g has 54mbps raw throughput or about 20mbps throughput after protocol overhead or 45mbps actual in turbo mode. If you application involves high speed bridging or copying large files over 100mb then 802.11g is worth looking at. Distance wise 802.11g will only provide the maximum 54mbps connection at close range usually less than 100 feet. After that the connection falls back to 802.11b speeds. 802.11g client devices are limited to 125mW output by the FCC at this time so their maximum range is less than the best 802.11b devices. 802.11g devices are more susceptible to noise than 802.11b devices because they use OFDM protocol. For compatibility 802.11g access points can be set in dual mode b and g supported. There is one issue with this as soon as a 802.11b client associates all clients on the network are kicked down to 802.11b speeds. This can be solved by putting the access point in g only mode. But then the vast majority of existing b clients will not be able to connect.
802.11a
802.11a provides the same speed 54mbps connection speed as 802.11g using the 5 ghz UNIII band. Currently 802.11a allows for the most actual bandwidth and up to 45mbps of actual throughput in 2x mode vs around 20 for standard 802.11a and 802.11g. This band is less crowded then 2.4ghz allowing for a connection in business or special situations. the 5ghz band also passes through certain types objects better the the 2.4ghz band one of them being crowds of people. 802.11a would be good in a trading floor application or maybe hospital. For distance 802.11a does not have the range of b or g. Compatibility wise 802.11a will not talk with b or g products. However many access points and clients offer dual mode or 802.11b g and a.
What is 108Mbps 802.11a 2x mode? How fast is it really?
The 802.11a 2x mode uses more than one 5Ghz channel to increase the overall bandwidth this is possible because there are more channels available and the band is less crowded than the 2.5Ghz band that 802.11b and 802.11g operate at. In our testing we saw overall throughput of up to 45mbps at close range.
What is 108Mbps 802.11g turbo mode? How fast is it really?
The 802.11g turbo mode uses more than one 2.4Ghz channel to increase the overall bandwidth. Because there are only 3 non overlapping channels at 2.4Ghz channel 6 must be used. Even when the center channel is used there is still some overlap if you are running access points on channels 1 and 11. For this reason 802.11g turbo is better used in a situation where just one access point is required per location. In our testing we saw overall throughput of up to 45 mbps at close range.
