Microsoft Wiffler lets smartphones use free WiFi from moving vehicles

Microsoft Researchers 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, researchers took it for some test drives in Amherst, Mass, Seattle and San Francisco.

How so? Wiffler is smart about when to send the packets. It doesn't replace 3G, it augments it and transmits over WiFi simultaneously, allowing users to set WiFi as the delivery method of choice when it is available -- and when an application can tolerate it. Not every application can handle even a few seconds delay in the stream (VoIP) -- and WiFi tends to drop more packets than 3G does. But many apps can handle even a minutes-worth of delay perfectly well (messaging).

"We try to ensure that application performance requirements are met. So, if some data needs to be transferred right away (e.g., VoIP) we do not wait for WiFi connectivity to appear. But if some data can wait for a few seconds, waiting for WiFi instead of transmitting right away on 3G, that can reduce 3G usage," Ratul Mahajan told me in an e-mail interview. Mahajan is a researcher with the Networking Research Group at Microsoft Research Redmond. Mahajan worked on the project with two teammates, Aruna Balasubramanian and Arun Venkataramani, both of whom are researchers at the University of Massachusetts Amherst.

Interestingly, the researchers didn't actually use Wiffler with mobile phones during their tests. They ran phone-like applications on the embedded computer. But the project team does envision Wiffler as a technology for smartphones, perhaps embedded directly into the smartphone. It could also be adapted to run in an in-vehicle infotainment system.

Moving vehicle

While this research focused on using free WiFi in a moving vehicle, Mahajan says Wiffler could be used in other ways. Carriers may want it to for private WiFi services that augment their 3G/4G data networks. It could be used by pedestrians who might get even higher WiFi offload rates if they were wandering in a city with their Wiffler-equipped smartphones. It could be valuable in a stationary setting, too, like hanging out at Starbucks.

"Today, the WiFi/3G combo management is highly suboptimal. Today, smart phones tend to use WiFi connectivity only when they are stationary and not use WiFi connectivity when they are on the move. At the same time, they experience poor application performance when the WiFi connectivity is poor because they happen to be far from the AP (access point) or because the WiFi network is congested. This experience occurs because the devices insist on using WiFi whenever they are connected, largely independent of the performance of WiFi. Our technology provides an automatic combo management that is aware of application performance," Mahajan says.

Next up, the crew plans to test the Wiffler protocol in other uses, including the 3G savings "in a setting when users have Wiffler running all the time rather than just driving. Another is to understand current smartphone traffic workloads to get a sense of how much traffic individual applications generate; this is important because data for some of the applications can be delayed and for some it cannot be delayed," Mahajan explains.

There is no association of Wiffler to Windows Phone 7 at this time. I hope it stays that way. Wiffler could be of best use if it were something that any handset on any phone could have. Plus, by the time a commercial product came to market based on Wiffler, Windows Phone 7 will either have found its niche, or died.