13
Tracking of Moving Objects with Accuracy Guarantees
Alminas ˇ
Civilis
1 , Christian S. Jensen
2 , and Stardas Pakalnis
2
1 Vilnius University, Vilnius (Lithuania)
2 Aalborg University, Aalborg Ost (Denmark)
13.1 Introduction
In step with the increasing availability of an infrastructure for mobile, online locationbased services (LBSs) for general consumers, such services are attracting increasing attention in industry and academia [9, 18]. An LBS is a service that provides
location-based information to mobile users. A key idea is to provide a service that is
dependent on positional information associated with the user, most importantly the
user’s current location. The services may also be dependent on other factors, such as
the personal preferences and interests of the user [3].
Examples of LBSs abound. A service might inform its users about traffic jams
and weather situations that are expected to be of relevance to each user. A friend monitor may inform each user about the current whereabouts of nearby friends. Other
services may track the positions of emergency vehicles, police cars, security personnel, hazardous materials, or public transport. Recreational services and games,
as exemplified by geocaching [8], the Raygun [7] game, may be envisioned. In the
latter type of game, individuals catch virtual ghosts (with geographical coordinates)
that are displayed on the screens of their mobile phones.
Services such as these rely to varying degrees on the tracking of the geographical
positions of moving objects. For example, traffic jams may be identified by monitoring the movements of service users; the users that should receive specific traffic jam
or weather information are identified by tracking the users’ positions. Some services
require only fairly inaccurate tracking, for example, the weather service, while other
services require much more accurate tracking, for example, location-based games.
In contrast to Chap. 12, this chapter does not consider issues to do with user interface design, but rather concerns support for fundamental functionality that may be
exploited by mobile services.
We assume that the users are equipped with wireless devices (e.g. mobile phones)
that are online via some form of wireless communication network. We also assume
that the GPS [20] positions of the users are available.
To accomplish tracking with a certain accuracy, an approach is used where
each wireless device, termed “a moving object,” monitors its real position (its GPS
Tracking of Moving Objects with Accuracy Guarantees
Alminas ˇ
Civilis
1 , Christian S. Jensen
2 , and Stardas Pakalnis
2
1 Vilnius University, Vilnius (Lithuania)
2 Aalborg University, Aalborg Ost (Denmark)
13.1 Introduction
In step with the increasing availability of an infrastructure for mobile, online locationbased services (LBSs) for general consumers, such services are attracting increasing attention in industry and academia [9, 18]. An LBS is a service that provides
location-based information to mobile users. A key idea is to provide a service that is
dependent on positional information associated with the user, most importantly the
user’s current location. The services may also be dependent on other factors, such as
the personal preferences and interests of the user [3].
Examples of LBSs abound. A service might inform its users about traffic jams
and weather situations that are expected to be of relevance to each user. A friend monitor may inform each user about the current whereabouts of nearby friends. Other
services may track the positions of emergency vehicles, police cars, security personnel, hazardous materials, or public transport. Recreational services and games,
as exemplified by geocaching [8], the Raygun [7] game, may be envisioned. In the
latter type of game, individuals catch virtual ghosts (with geographical coordinates)
that are displayed on the screens of their mobile phones.
Services such as these rely to varying degrees on the tracking of the geographical
positions of moving objects. For example, traffic jams may be identified by monitoring the movements of service users; the users that should receive specific traffic jam
or weather information are identified by tracking the users’ positions. Some services
require only fairly inaccurate tracking, for example, the weather service, while other
services require much more accurate tracking, for example, location-based games.
In contrast to Chap. 12, this chapter does not consider issues to do with user interface design, but rather concerns support for fundamental functionality that may be
exploited by mobile services.
We assume that the users are equipped with wireless devices (e.g. mobile phones)
that are online via some form of wireless communication network. We also assume
that the GPS [20] positions of the users are available.
To accomplish tracking with a certain accuracy, an approach is used where
each wireless device, termed “a moving object,” monitors its real position (its GPS