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fork(2) [soylentnews.org] writes:

      IEEE Spectrum carries an article Why Wi-Fi Stinks -- and how to fix it [ieee.org] (doesn't seem to be paywalled). Basically, the idea is to optimize the use of the Wi-Fi spectrum with better routers capable of using (and relinquishing, when necessary) special-use channels using Dynamic Frequencly Selection (DFS).

DFS acts as a high-speed traffic cop -- when it spots a radar signal in one of these protected channels, it quickly shifts all Wi-Fi traffic to another lane. There are a few rules about how this traffic cop works: It must listen for radar for at least 60 seconds before declaring a channel free to use, then continue to listen while Wi-Fi traffic is on the channel. If the mechanism detects even a 1-microsecond radar pulse, the Wi-Fi transmitter must clear the channel within 10 seconds and stay off it for half an hour.

      The vast majority of mobile devices introduced in the last three or four years have radios that can operate in these bands and have the required software to respond to instructions from what is called a DFS master. But they need that DFS master built into the router to tell them when it's all right to use a radar-priority channel and when they need to move aside.

      The trick is to create a less costly and more effective technology to detect radar signals on channels. The article's author and colleagues at Ignition Design Labs in San Jose think they've figured it out.

We have designed an enhanced router, called Portal, which incorporates a full-spectrum radio scanner and a CPU dedicated to radar detection and channel management alongside standard router hardware. The scanner continuously sweeps the entire 5-GHz band for radar as well as for Wi-Fi traffic and general interference. Making this detection system completely separate from the Wi-Fi sending and receiving radio solves a lot of the problems of current radar-detection technology, which shares the main processor and Wi-Fi radio for radar detection as well as communications.

      Because the spectrum is finite, finding affordable, effective ways to use it is important in order to deal with the current and future data traffic jam.

Original Submission