Researchers Test WiFi Access From Moving Vehicles 155
Julie188 writes "Researchers from Microsoft and the University of Massachusetts have been working on a technology that would let mobile phones and other 3G devices automatically switch to public WiFi even while the device is traveling in a vehicle. The technology is dubbed Wiffler and earlier this year its creators took it for a test drive with some interesting results. Although the researchers determined that a reliable public WiFi hotspot would be available to their test vehicles only 11% of the time, the Wiffler protocol was able to offload almost 50% of the data from 3G to WiFi."
Researched this myself (Score:4, Interesting)
But once you have the physical layer taken care of, you can play cool little tricks like data queuing for WAPs to save cost. Locational awareness is also feasible to anticipate whether there will be a hotspot in a quarter of a mile or to go ahead with the transfer now.
Re:not gonna work (Score:2, Interesting)
There really needs to be a standard way for an access point to say "I have no wireless authentication, but I am not open" when advertising itself, to allow devices to respond appropriately.
Re:Yo moron (Score:3, Interesting)
Just because it doesn't work on your iFruit doesn't mean that it won't work with something that was designed for this purpose.
But how would a city bus line offering Wi-Fi negotiate carriage with every AP on its routes?
Re:not gonna work (Score:4, Interesting)
Already been done (Score:2, Interesting)
Re:Yo moron (Score:4, Interesting)
Re:Yo moron (Score:4, Interesting)
The main problem would be in tunnels and plain old congestion.
802.11p (Score:2, Interesting)
Re:Researched this myself (Score:1, Interesting)
The multipath and doppler effects SUCK. This is why Wimax doesn't work well in vehicles and why the Mobile Wimax variant is more popular in such realms.
The doppler problem is by far the more important one. WiFi is based on an OFDM modulation that takes advantage of the mathematical orthogonality of zillions (technical term) of low bitrate channels with respect to a given Fourier transform window. When the source or receiver is moving, the frequencies shift in a way that destroys their orthogonality with respect to that window and causes crosstalk between the channels. It doesn't just degrade performance, it pretty much obliterates it.