“It’s no longer a question of ‘to do or not to do’, China Mobile will implement the dynamic Cell-ID technology sooner or later. ” a friend said this to me, “the solution is there, and it’s just a matter of time because deploying it to the entire network may take a long time.” The reason, China Mobile is not happy that more and more LBS services ‘steal’ its cell location data.
The background – where does the location data come from?
Where does the location data come from? You may say GPS. Fair enough, GPS can give you accurate location (longitude/latitude). But how many mobile phones have GPS chips? All latest smart phones have it, but still it’s a small percentage. It’s the trend to have GPS on the phone, but it may take years (especially in China where many local brands and Shanzhai phones are quite popular). So for majority of phones which have no GPS powered, how to get the location? and the second issue is that GPS needs outdoor environment for better signal, i.e. if LBS services only rely on that, you have to tell your users not to use it inside the building, restaurant, hotel etc.
So we need other solutions. Since the mobile phone is always connected with base stations, so basically, if we know which base stations you are connected (i.e. which cell you are in), as we know the location of each base stations, we can somehow roughly calculate the locations (ref, A-GPS). The location acquired by this way may not be as accurate as GPS gives us, but it is ok to use for most of cases.
Then question comes down to: who has the location of the base stations. Well, it’s an easy question, of course, the operators, and in China, the biggest guy has the best network coverage is: China Mobile.
Why China Mobile is NOT happy?
Once you have the ID of the cell, by looking up in a database, you can get the location. “Currently, many LBS service would say they have the right to use the locations as they bought that database from third parties” my friend said, “but the issue is China Mobile never said its cell-location database is to sell!!” Alternatively, the database can be populated by crowdsourcing, Google seems doing this. But it needs huge resources and large user base. “But for those Chinese third-parties, they do not have it. ” he said. And it’s also true that Google is still in a bit trouble with the mapping license in China.
Anyway, the current situation is actually none of LBS services pay China Mobile for its own property, the location data.
Why Dynamic Cell-ID?
Dynamic Cell-ID is a way of dynamically assigning the Cell-ID that is reported to wireless devices by base stations. Rather than always reporting the same Cell ID, base stations report a different, dynamically generated Cell-ID. So, only the operator can map the dynamic Cell-ID to the fixed Cell-ID that is required to get the location (via this). In other words, if China Mobile (and later China Unicom, China Telecom) has this implemented, the LBS services have to pay the operators directly for the access.
If what I wrote down makes sense, then unfortunately, all LBS dreams still can not get around the operators until one day GPS phones can dominate the market.