Capture the Flag game using cell phones

Sunday evening's paper: Capture the Flag: A Multiplayer Online Game for Phone Users by Adrian David Cheok, Sze Lee Teo, Lei Cao, Le Nam Thang (for the ISWC05 conference):

This paper explores the concept of using smart phones to facilitate pervasive mixed reality, location-based, physical and social gaming. The interaction and communication between the virtual and physical worlds are explored and studied using a mixed reality version of the capture-the-flag game. In this game, players from two different paradigms, virtual and real, compete and collaborate in a social gaming environment using mobile devices and network system. (...) Unlike Human Pacman and ARQuake where players are equipped with head-mounted displays and complicated wearable equipment, players can move freely over wide outdoor area with true mobility and minimal hardware.

The basic goal of our smart phone-based CTF is to capture the opponents’ flag by acquiring it from their base and bringing it to the home base. (...) There are two player roles; smart phone players play as Knights while online players play as Guides through desktop PCs and they are connected via the Internet. The Knights whose positions are tracked via Global Positioning Unit (GPS) have to set her team’s “castle” in the beginning of the game by placing their own physical flag (a Bluetooth embedded device) on the ground. Once done, a virtual castle and a flag appear at the corresponding location in the Guides’ 3D map and in Knights’ smart phone interface. (...) Communication between various players using text messaging is an ongoing process throughout the game.

Why do I blog this? this is a good example of a low-tech approach of pervasive gaming using text messenging + GPS and bluetooth (unlike augmented reality tech). I'd be happy to know more about the tests/usage.