802.11n to be Approved Next Week
If all goes well with the Joint Proposal team working on establishing 802.11n next week, we will see very promising Wi-Fi products in the near future. 802.11n marks the fourth largely used 802.11 specification, after 802.11a, b and g. So what's so different about this new n spec you say? Well first off if uses a different technique for transmitting and receiving data via multiple streams, dubbed MIMO (Multiple Input, Multiple Output). Keep in mind that 802.11b permits a throughput of 11 megabits/sec while 802.11g has a throughput of 54 megabits/sec (108 megabits/sec in turbo mode on some routers) while you read the following quote:
Task Group N will produce a standard that uses multiple antennas and a host of other strategies to produce at least 100 Mbps of raw throughput, but more likely 200 Mbps. Net throughput, or real data transferred, will be much higher than the current 50% of raw data passed across.
This means that the door will be open for big companies like LinkSys and Netgear to unveil those high-end routers and access points utilizing 802.11n that they've been tinkering with in the lab. Imagine what the next generation of hackable LinkSys WRT54G routers would be capable of. You may have already seen several routers in stores labeled as "pre-n", which basically tried to introduce their product before the standard was created. These were released so early that they might not abide with the complete and final spec and furthermore not function with other non-pre 802.11n devices. It will still take some time for 802.11n to find its way into the latest Intel Centrino chipset or that MacBook Pro, so I'd suggest holding off purchasing a potential 802.11n product until the market adapts. Wi-Fi Networking News has the full scoop, as does Mobile Pipeline. Update: ArsTechnica has some more info including a better description of MIMO as follows:
According to Intel's white paper on 802.11n, MIMO is a method of using multiple antennas in both the sender and the receiver to increase the amount of bandwidth and the overall reliability of each link. SDM takes advantage of MIMO by slicing up a single input data stream into multiple parts, which are then transmitted in parallel before being put back into serial order by the receiver.