Position Paper: Venky Krishnan, Glenn Steiner

27-Dec-2000

Hewlett-Packard Laboratories
1501 Page Mill Road
Palo Alto, CA 94304, USA

Hewlett-Packard is interested in seeing the development of a consistent location infrastructure for a wide range of clients, whatever the source and meaning of the location, and whatever the client. Location information has utility for desktop and nomadic users, as well as for phones and other appliances. Physical location can be provided from the cellular or enterprise network, from a GPS signal or even a user, and all these techniques are likely to co-exist. Similarly, various techniques are being explored to provide semantic location. It is important for the industry that location information can be accessed in a consistent manner across all these technologies, and especially that it can be made available to value-added service providers.

Clearly, privacy of location information is a very important issue. We believe that access to location information must be under the control of the user, in a straightforward manner, so that the user can determine when and which services are allowed access to location and possibly personal information.

We are developing an architecture called cooltown that will meet these requirements, based on the web as the underlying infrastructure.

The cooltown Project at HP Labs envisions a world where people, places and things are first class citizens of the Web, and have Web representations that participate in E-services (http://www.cooltown.hp.com). Web-based appliances and E-services give you what you need, when and where you need it for work, play and manage your life. cooltown bridges the physical and online worlds, bringing the benefits of Web services to the bricks-and-mortar world where most people still live the majority of their lives.

Customized services are provided based on the knowledge of the user's location. Within cooltown there are two fundamental types of location:

1. Semantic location specifies the position of a person, place or thing within a larger context we define to be a space. An example of a space is a conference room, or a shopping mall, or a bus-stop. A space carries context information about a local environment and its resources. A space is represented by a Web page. For example, Figure 1 shows a conference room space with related information such as the nearest bathrooms, as well as resources such as a printer and a projector. Within cooltown, a person's presence in a conference room gives him access to the conference room resources and information which may be related to the room.

2. Physical location specifies a location of a person, place or thing based upon an absolute position provided by a coordinate based system such as GPS or cell phone triangulation. An object location may be given by a set of coordinates such as a (latitude, longitude) pair. This location can be provided with a varying degree of precision. The object location can be used in connection with global services that personalize information based upon the location. An example of a service is to show a person's location superimposed on a street map for navigation purposes. The use of physical location in cooltown is similar to MapBlast.

Location awareness may also be expressed through Geographic Location, such as a city name or a zip code, which may be viewed as location information spanning both semantic and physical location spaces. All objects in cooltown may have both Semantic and Physical location information associated with them. Service providers frequently utilize different types of location information to provide services. A Yellow Page service requires the user's current zip code or city name. On the other hand, a Conference Call service enabling a meeting between two conference rooms may not require any physical location information but will need information on the characteristics of the room (what audio/visual devices are available, nearest printers etc.).

Objects may not have associated with them all the location information needed by a specific service. cooltown includes the notion of Location Translation Agents. The agents maintain relationships between the different location types and provide the required translation that would enable the accessed service. For example, a person in a conference room may want a list of nearest restaurants. A Location Translation Agent will translate the room's location to a Latitude/Longitude and may further translate it into a zip code to meet the Yellow Page restaurant service's needs. This translated location information may then be used to access the required Yellow Page service.

Within cooltown all location descriptors are represented in XML. This Web based protocol provides a high-level interface between devices and services. XML also enables easy translation of location information as well as providing extensibility for descriptor data as new information is discovered relating to semantic and physical location. Location descriptors may be updated based on information available and may be refined over time based upon new or better location information. A device with an attached GPS receiver knows its physical location. If it establishes a relationship with a device that has semantic location information, then both the devices may update their descriptors with the newly discovered location information.

In cooltown, beacons are one mechanism for providing the semantic location of a space. A beacon in the form of an IR or RF emitting device advertises the location information by sending out a Web based URL. A Personal Access Devices (PAD), such as a WAP enabled cellular phone, which is in range of such a beacon will be able to access the Web page pointed to by the URL. This Web page provides access to location descriptors identifying the semantic and possibly the physical location of the space and associated services.

Within cooltown we are very concerned about personal rights and privacy. The fundamental notion is that when a user enters a space, the user can discover services that are associated with the space without revealing any information about themselves. Thus compared to cell-phone triangulation, in cooltown the user can access location-based services without revealing where they are. Should the user be willing to release who they are, or limited personal information such as food preferences, then a service would be enabled to provide more specialized data based upon the user's released information.

By providing a Web presence for users, places and things, and exploiting the explosive growth of Web based services, we have put together several demonstration scenarios for location-based services, including in a conference room, museum, bookstore and cafe. We have also applied the same notions to scenarios around transportation. We continue to explore issues regarding location awareness in the cooltown project.

Participants

The cooltown project includes a number of people at HP Labs. The people working on location based services are Venky Krishnan, Gene Becker, Debbie Caswell, Gita Gopal, Tim Kindberg, Steve Loughran, Jeff Morgan, Miranda Mowbray, Mirjana Spasojevic, Mike Spratt, Glenn Steiner & Steve Wright.

Points of discussion