How will the increased spectrum affect installed 802.11a products that have fewer channels?
The radios will have to be upgraded to be compatible. Existing networks will likely be a mix of standards, and they will be interoperable. It is going to take a while for the FCC to approve this change, so it will be some time before products start to hit the market. But the FCC has created an interesting situation. Everyone looked at 802.11g as the natural path forward from 802.11b because they are in the same 2.4 GHz spectrum. But I think this will make 802.11a more desirable down the road. The range for 802.11a has been increased to about 100 feet. It has improved, but it will never be as far as 802.11b. Why is the FCC proposing to add spectrum to 802.11a?
The FCC wants to promote wireless communication, and this is an avenue to do it without getting into licensing wars. It sees this as a way to get Internet access to remote areas at reasonable prices. When is this change likely to go into effect if it is approved?
It's likely to be resolved by the end of 2003. How do you recommend enterprises react to this? Should they wait and see or go with 802.11a as it is today?
The early sales of 802.11a have been primarily to verticals such as health care and universities. Systems based on the 802.11b standard often do not have enough bandwidth to handle the large number of students that would be using the system in a lecture hall, for example. But for companies that have installed 802.11b networks, it may make sense to upgrade to g. That way they will not have to install additional access points. A pure 802.11g network is not that far off of an 802.11a network, in terms of sheer bandwidth. The bigger issue is interference. And that is what will drive the desire for 802.11a. Eventually, devices will have cards for all of the standards. But multiple standard access points present their own challenges because the standards behave differently. An 802.11a network requires more nodes than an 802.11b network. What about 802.11b/g, which have far fewer channels anyway? Don't those standards need the spectrum?
There is not much that you can do for 802.11b and 802.11g. They are limited by the specification itself. The 802.11a standard has the potential to absorb a lot of wireless traffic down the road. Interference is going to be a problem with 802.11b and 802.11g, particularly in large metropolitan areas with tall buildings. Expanding the number of channels available for 802.11a will give us a way to migrate in the future, when we need to get past b and g. What does this mean in terms of global adoption of 802.11a?
This will end up making 802.11a compatible with the spectrum that it has been allocated in Europe. It will also be largely compatible with what is available in Asia, though right now there is not much use of 802.11a in Asia. How are vendors addressing these different standards?
The vendors that have an installed base, like Cisco Systems Inc. and Symbol Technologies, are trying to move toward 802.11g. Companies that do not have the same installed base are jumping into 802.11a rather quickly. Enterprises that move from 802.11b to 802.11a will have to add access points. On the device end, vendors will just begin to add multi-mode cards. Right now those are at a 30% premium.
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Advice: Wireless LAN expert Lisa Phifer
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