Researchers find Wi-Fi use in cars challenging, develop new protocol

Researchers from Microsoft, the University of Massachusetts at Amherst and the University of Washington have been testing whether people can use applications, such as VOIP and web browsing, while sitting in a moving vehicle in an area that has an outdoor wide-area Wi-Fi network. The passengers in their experiment rely on outdoor Wi-Fi base stations for connectivity. Their conclusion: people experience frequent disruptions in connectivity because Wi-Fi handoffs are difficult to achieve. As a result, the researchers developed a protocol called ViFi which minimizes disruptions. According to the paper, ViFi “allows people successful short TCP transfers and doubles the length of disruption-free VoIP sessions compared to an existing WiFi-style handoff protocol.” You can download their paper entitled Interactive WiFi Connectivity for Moving Vehicles.

Right now, most Wi-Fi use in vehicles consists of people connecting to a Wi-Fi access point inside a train, car, bus or ferry, which in turn communicates with cellular or WiMAX base stations, or satellites. Between the passengers’ laptops and the Wi-Fi access point inside the vehicle, there’s no handoff problem. But in a large city with numerous base stations scattered across an area, it is challenging, but not impossible (as shown by a number of municipal Wi-Fi networks used by police officers) to run applications on a laptop while on the go. Note that many police cars have an access point in the trunk, which allows better connectivity.

But here’s another question: do we need more distractions in cars? Aren’t people distracted enough by cell phones?

Europe allocates spectrum for “talking cars”

The European Commission has taken intelligent vehicles and infrastructure one step further. It has decided to set aside part of the radio spectrum for road safety and traffic management: 30 MHz of spectrum in the 5.9 Gigahertz (GHz) band which will be allocated within the next six months by national authorities across Europe to road safety applications, without barring other services already in place (such as radio amateur services). The goal is to allow people to develop wireless smart vehicle communications systems (co-operative systems) that would let cars talk to other cars and to road infrastructure. For example, a car ahead of you (or the road infrastructure network) can warn your car about slippery road conditions or an accident that has just occurred, allowing you to avoid a particular route. Had such a system been in place, it would have saved lives in recent deadly tunnel accidents and fires in Switzerland and Austria. Read more about the European “smart vehicle” initiative.

Does anyone know if there is a similar move in the US to allocate spectrum for cars that talk to road infrastructure?