Position　Dependent　Area Information　Guide　

Authors:

Miwako Doi

Hiroshi Sugiyama

Koichi Hasebe

 

Needs:

Toshiba provides an area and train guide service “Ekimae-tanken-club” via Internet. This provides 4 types services based on stations in Kanto area and Kansai area; a transfer route and timetable guide, a navigation map to the destination, a town guide, and hotel reservation. Users access these services on PC http://ekimae.toshiba.co.jp/ or PDC http://ekimae.toshiba.co.jp/ss/ and select the base station. The number of accesses is 1M PV per day. These services based on stations will be extended to based on the current user position according to the propagation of position service infrastructure. Extension to the position dependent service faces following problems.

Users of position dependent area information service are drivers and walkers. Driver’s speed is much faster than walker’s speed is. The range of pre-reading position dependent area information for drivers are larger than the range of walkers. Now user profile supported by WAP describes static user information; who is what are the preference, etc. User profile for position dependent are information service must describes the dynamic user information; where she is, how she moves, etc.

Mobile device users want to get position dependent area information service without talking that they are. If the position determined system has to know who owns a mobile device, the anonymous position dependent area information service is not guaranteed. Anonymous service is a key for success of position dependent area information service. 　

On the other hand, the position dependent area information service must identify the current client terminal. The position dependent area information service can not provide the appropriate service to the client without identification. When the user buy something from the position dependent area information service, the service server must make an authentication of the client. If the service server make the authenticated information correspondent to the client terminal identification, the service server can guess the client position history based on the authentication information and the client terminal identification.

The current user position data determined by a mobile device may be numerical data like longitude and latitude. Users cannot recognize their current position as numerical data but as nominal data. They recognize their position seeking landmarks or address denotes. So the position dependent area information service must transfer numerical position data to nominal position data. If the representation of numerical data depends on the position determination system, the position dependent area information system must build and maintain several transfer table between numerical and nominal position data. It is boredom.

Numerical position data determined by mobile devices include error. The minimum error is less than 1.5m. The maximum error is more than 100m. In a car navigation system, the direction of the car is determined and position error has an effect on the position of the determined road. So the position error effect may be recoverable. In a person navigation system, the direction of the person is not determined. The position error has an effect on the direction and the position. So the position error effect is not recoverable and a person likes to be lost much easily. It is time and cost consuming to improve the accuracy of position determination. So the new complement way of position determination error is need to provide a conscious and cost effective person navigation service.

Functions of WAP Gateway:

In order to solve these problems, WAP gateway provides following intermediation functions;

WAP supports the dynamic user profile; where she is, how she moves, etc. The dynamic user profile does not include authentication information but includes the client terminal ID. So the dynamic user profile offers the enough information for anonymous service.

WAP gateway randomizes the client terminal ID and authentication information for the anonymous service. The non-tracing randomization guarantees the secure position dependent area information service.

WAP gateway transfers the several numerical data into the landmark (the nominal position data) which the client easily find out. This transfer function of WAP gateway decreases the double investment of each service server for the transfer table.

GPS works well in urban, but doe not work well in a downtown. The QOS control by WAP gateway guarantee the constant accuracy of the determined position.

Proposal:

Our proposal is the dynamic user profile for anonymous service.