Apple's recent MacWorld announcement that they're using technology from Skyhook Wireless to do location-related services on the iPod Touch and iPhone came as no surprise to me. I've been tracking Skyhook since they were founded and I've always liked the concept they've implemented a lot. At the risk of oversimplifying what Skyhook does, basically they have a database of locations that correspond to a pattern of signals from any Wi-Fi access points near that location. The data is obtained via the sensing of beacon frames and in no way eavesdrops on actual communications between a given AP and a given client. This is a form of RF fingerprinting, and the technique is not limited to Wi-Fi. It's just that there are an awful lot of APs in urban areas, with more coming online all the time, so a little driving around to gather data and voila, a database that can be used to determine location quite accurately. In urban locations that lack a clear view of the sky, Skyhook's service can be even more accurate - and faster - than GPS. And, assuming the presence of a Wi-Fi radio and no GPS chip in the subscriber unit, as is the case with the iPhone, Skyhook's solution is inexpensive as well. So, no surprise that Apple signed them up as a supplier.
I spoke with Skyhook CEO Ted Morgan last week, and he mentioned that the deal with Apple is not exclusive. In other words, we might soon see Skyhook technology in all kinds of location-based products and services. The key challenge for the company is to broaden the number of locations where it's built databases - but note this is just a matter of driving around with a car full of equipment, and they're doing that now in many cities. The barriers to entry are high, so I don't expect to see a lot of competition for Skyhook.
And, no, the Skyhook technique won't work in very rural areas or the middle of the ocean. But neither will your iPhone.
Mathias is a principal at Farpoint Group, a wireless advisory firm in Ashland, Mass.
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good for LBS, but what about for navigation?
This sounds great for applications where it finds a general location for you and then can recommend where the closest Chinese restaurant is, but even in densely urban areas wouldn't the limitations of Wi-Fi make this virtually impossible for navigation / driving directions?
Also, what happens when more APs come onto the network or if APs vanish from the area? Doesn't this fluidity limit the technology?
Re: good for LBS, but what about for navigation?
Think of this as just like GPS - a way of determining the location of the receiver on earth. The database allows mapping "Wi-Fi" coordinates to earth coordinates, so any app should work. I believe it's working with Google Earth today. As for changes in Wi-Fi configuration, the system can extrapolate. Usually there are more Wi-Fi APs present than are required at any given location, so if one drops out, no big deal. And re-driving the locations occasionally takes any changes into account. Eventually, I think it will be possible for every user to update the database automatically, so the accuracy just gets better over time without any particular effort on Skyhook's part.
Thx. Craig.