Alcatel Position Paper
W3C Workshop on Location
Date: 14/12/1999
Object:
Access to Internet from mobile device like cellular phone, PDA, Laptop or others, give the opportunity to develop new services, or adapt existing services taking into account specific aspects relative to the mobility context, as the mobile user location.
Capacity to deliver in a controlled and standardised way the information to content provider is mandatory to insure mass-market adoption of this new technology.
The current paper presents how Alcatel can contribute in the W3C workshop and some output expected from the workshop.
Requirements:
The information relative to the current position of a mobile user can be retrieved from different sources: user input, a dedicated unit included or connected to the mobile device, or from information stored in the device or in the network. These different ways to collect the information have to be seen as complementary and the specification will have to address all possibilities.
At least three main entities are involved in the delivery of position-related information:
The diversity of source of information has to be hidden to the content provider.
This conduct us to identify a logical entity, called "Location Service", in charge to provide to a mobile user agent the information relative to its current location. This service can be an internal function of the mobile device, or an external service operated either by the network operator, or by a third parties under a specific agreement with the operator. The purpose of this service can be to provide raw information, like latitude and longitude, or to provide more elaborated geographical information, like district name, zip code, etc…
An open interface between the mobile and the service must be standardised to let the market provide independent and interoperable solution.
The information exchanged between the mobile and the "Location Service" can concern network characteristics and so are also very sensitive for the Telecom operator. Authentication of the two parties and security of the exchange are strong requirements for this interface, in order to preserve users and operators interests.
The specification of this interface will be based on exchange of XML documents (RDF), over HTTP or WSP session, but not exhaustively. Alcatel proposes to contribute in the specification of such interface.
The privacy of the user will have to be guaranteed, this means that the user will have to formally agree on delivering the location information, in the format requested by the content provider.
The format of exchange by which the content provider will request, and will retrieve the location information should be compatible with several implementation options. CC/PP should be considered first.
Complements:
The following schema shows a possible flow of information between the three main actors mentioned above:
The content provider requests to the user agent the location information needed, or pertinent for the service it delivers (format, level of precision, etc..). The format on which the two parties will finally agree should be the result of a negotiation.
A user agent should be able to select among several Location Service when appropriate.
0: Initial content referencing position-related information
1: Request to determine user location in the format requested in 0. Optional parameters will be relative to network status and capabilities.
2: Answer with location information
3: Request with position information
4: Content with location-related information
The flow of requests and response between the different actors can be different, other possible flow if the "Location Service" works, as a proxy should be:
In case of a WAP Gateway the flow should be the following:
