Position Paper: Venky Krishnan, Glenn Steiner
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
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.
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