Monthly Archive for January, 2007

In an ideal world access to the Internet would be ubiquitous and instantaneous. We’ve come quite far in the past couple of years and Internet applications on mobile phones usually work quite well as long as the network connection is stable. This is usually the case at home, in a hotel room, at work, while waiting for the bus, queuing up in the supermarket or in general, while your are not moving much. But in a car or on a train things are quite different and I just became painfully aware of this fact once more as I spent the better part of the day in a train returning home from a three week trip and frequently resetting my mobile phone.

While on the train, network coverage varies greatly, from UMTS coverage over slow GPRS to outright nothing for several minutes. Both phone and applications didn’t take this very well. Such an environment creates three problems: Even while the train roams through covered areas data transmission is not quite continuous in GPRS as the phone needs to interrupt the data transfer for a couple of seconds every time the mobile moves to a new cell. Applications can usually handle this quite well. Then, there are times when network coverage is completely missing. Many applications don’t like that at all as they assume that once they’ve connected to the network they can send and receive data at any time. And then there is the case when the phone moves to a new cell and the network suddenly pretends it doesn’t remember it had a connection to the phone anymore. This is usually due to bad network engineering but it still happens often enough. In this case most phones simply drop the connection without reestablishing it. Applications, however, often don’t recognize this and think they are still connected. In the best case the user can then exit the application and restart it. In the worst case, the user has to restart the phone to persuade the application to cooperate again.

Dear mobile phone and application developers: I very much value your work but please do not only test your software on a couch but do consider moving scenarios for Internet applications as well. Test your mobile phones and applications in trains and cars! Mobile phone operating systems must give the application the means to detect the state of the network connection and applications must use this information intelligently. An eMail application for example could abort downloading eMails or continue to do so in the background once connection to the network is temporarily lost instead of just blocking indefinitely. Also, applications should indicate to the user that the network is temporarily lost and offer to pause/exit/resume data transfers instead of sitting there and waiting for the next bit to arrive five minutes down the road. Lot’s of work still to do here!