Klaus David and Rolf Kraemer {[david]/[Kraemer]@ihp-ffo.de}

20.12.99

Position Paper from lesswire AG (Wireless Solutions for Local Worlds, http://www.lesswire.de/) for the W3C/WAP Workshop on Position Dependent Information services in Sophia Antipolis, 1 - 2.2.99

1. Introduction

The first location aware information services are just about to be introduced in cellular networks with, for example, the teletraffic applications. Typically in these applications, the user initiates the application, like by asking where am I, how can I drive to town x/ road y from here, where is the next parking lot etc.

The lesswire Middleware for location aware information, the so called LocalNavigator, adds to these scenarios event oriented applications. One of many application examples for this approach would be that while I am approaching road y be distance z, I get an information on my browser of this "event". Also, other events could be triggered, like the start of the opening of the garage door, etc. Each combination of mobile objects with areas can be marked to be event sensitive. In case of the specified condition become true, the event is fired and indicated to the specidied set of mobile clients.

 

2. Details about Information Flow

For the above scenario becoming a reality the following information flows, detailed in figure 1 are required. The Browser could be an HTML Browser as shown in the figure, but also an XML or WML Browser, depending on the capabilities of the mobile terminal used.

Information flows (1), (3), (4), and (5) are the "normal" information flows. With flow (1), a user can request something, like where am I, and also get the answer for this request displayed on the browser. Such a request (1) would be received by the Internet Server, using CGI (3) the LocalNavigator Server (4) would be activated. The LocalNavigator gets the position of the mobile client from the Location Server (5). From the Data Base Server the appropriate map or other relevant data is provided.

On top of this "standard" scenario two additions are proposed:

• The LocalNavigator can fire "Events", like if a certain distance to road y is reached. This event will be transmitted to the event manager on the mobile terminal side which can than initiate any appropriate action for that event. In the case that some location aware information is available for a mobile client the event manager initiates the local browser with the URL that holds the information. The browser in turn will carry out a Get (ServId, URL) operation and will get the requested information as usual.

• Secondly, the location client can facilitate the localisation of the client. This could be the cell ID given to the Location server and mapped into a position information suitable. Any other location data information can also be used for absolute position but also for proximity information. A generic format is requested for this location information that should be composed of at least the following items: {location information, accuricy estimation, absolute/relative indicator}

Figure 1: Software Module Relationship

1. Conclusion

For a new "class" of location dependant applications lesswire AG proposes an additional information flow allowing to introduce event oriented location services. An example is an "Event" triggered by a certain vicinity to a chosen target. The Event Server should be able to indicate such events to the browser based on received event information.