Pushing Wi-Fi's Limits: Problems and Solutions

securitas writes "Forbes technology columnist Arik Hesseldahl discusses the problems with 802.11x Wi-Fi - speed and range - and how to push its limits in a pair of his Ten O'Clock Tech columns. He discusses the alphabet soup of Wi-Fi standards, so-called 'Super G' dual channel bonding that allows two of 11 channels to act as one (and the interference problems that ensue), and the multiple input/multiple output (MIMO) method 'using multiple antennas to break a single, high-rate signal into several lower-rate signals' that could be a solution. Pushing Wi-Fi's Limits, Part Two focuses on repeaters, Wi-Fi mesh networks, WiMax and a company called BelAir Networks that has deployed several Wi-Fi mesh networks."

Comments

Real issue

[kneecarrot]

While standards and spectrum sharing are definitely factors, hardware must move quite a bit forward if it is going to become more useful than small home networks and looking cool at a Starbucks. The real problem right now is the quality of the radio chips coming out of Taiwan. They are typically way under specified range and allow for alot of bleeding between channels. The average home user won't notice it, but when you are rigging up multi-antenna setups or relying on precise timing for a repeater, it matters to a HUGE extent.

Re:use more power

[ofdm]

This is, unfortunately, a common misconception. Increasing the range of 11b means that the available bandwidth has to be shared more widely - meaning that each user gets less bandwidth, which is to say data throughput.

Imagine if you will, a world where you could hear everyone talking within a block of you. Sounds great - you can hear your stereo from a mile away (well, this already happens). Unfortunately you can also hear everyone elses stereo, and everyone else talking, and their refrigerators humming, and their dogs barking. The net result is that you can't hear anything clearly. It's very much the same as being in a very full pub towards the end of a horse race - everyone's making a tonne of noise, and you can't understand much of it at all.

The solution is to have smaller cells, in the limit pico-cells, where an individual user gets the full channel to herself, and 10m away another user gets their own full channel. An alternative is to have large cells, but with APs having different non-overlapping frequencies - so that the cells are isolated in the same manner as for the pico-cells. Sadly, the lack of spectrum for 11b at 2.4Ghz makes this second solution unrealistic.