Security and privacy in location-based services by heterogeneous networks

Last modified: September 3, 2004

Mobile user-friendly multimedia terminals with broadband radio access combined with satellite receivers for geographical positioning signal will provide a ubiquitous platform for novel commercial services based on information about the geographical position, velocity and time of the individual or vehicle. The project's hypothesis is that this geographical position and movement data service will be best based on the federation of satellite and terrestrial mobile networks. Hence we will identify and investigate the technical challenges of information security resulting. The heterogeneous radio access networks approach will be beneficial both to commercial service providers and public institutions like police, ambulance, fire and other rescue brigades for a more efficient operation during emergency situations in both urban and rural areas.

The overall objective. Investigate and develop distributed security algorithms for advanced location systems and networked services based on the federation of emerging satellite and terrestrial mobile network services.

The research problem. There is a major drive in information and communication technology for mobility aspects. Mobile and wireless systems are expanding rapidly and globally for a wide range of services. Of particular interest here is new mobile personal communications system and satellite navigation systems. Currently, one very significant impact is the industry motion to employ Internet data communications in mobile systems. Another significant future impact will be location awareness of mobile terminals provided by satellite systems. These trends require new competence. A succinct description of the overall technical problem addressed can be formulated as: How can we provide secure ubiquitous digital location awareness, meaning personal locator and navigation services, for individuals and vehicles equipped with mobile networked computers, in taking the technical approach that commercial and public services can be provided by a combination of emerging satellite and terrestrial mobile networks, in the near future represented by GPS/GALILEO and UMTS/3GPP?

Through the location awareness requirements issued by US FCC and to be effective in 2001, cellular mobile communication systems must include capabilities of locating the user terminal with a given accuracy. The requirements are based upon emergency assistance. Given these capabilities, services/applications involving positioning information are evolving as one of the most interesting and commercially important new areas for the new generation of mobile systems. This is also reflected in the standardisation work by 3GPP ( where much effort is put into defining the environment for these services. User terminal position can be determined either by the terminal alone, by the network or as a combination. Regarding availability of 3G services, they will mainly be deployed in full scale in urban and some important sub-urban areas. This limits the availability of location information supplied by these systems to a sub set of geographical areas. Several European research projects related to these issues have been carried out.

Galileo is a 1999 initiative from European Commission to build a satellite-based global navigation system for fully commercial and other operations starting in 2008. A large part of the motivation for this project proposal stems from the Galileo activity and the co-ordinated ESA project GalileoSAT. (A very recent overview of satellite navigation can be found in the cover story of IEEE Spectrum April 2000, page 26-36. An excellent overview of technology and market expectations for personal locator services can be found in IEEE Spectrum February 2000, page 41) Independent of the very interesting proposal for "server-assisted GPS" experimented with in US and reported in the 2000 February issue of IEEE Spectrum, similar concepts have already been proposed to GalileoSAT by invitation of ESA/ESTEC [1], and also publised at ION [2]. The research will pursue to characterise and investigate a number of fundamental issues identified and motivated by this and related studies, including problems related to security primitives and protocols achieving integrity and privacy properties, and access control mechanisms for distributed position computations in an Internet-based environment.

There is a very strong and immediate ethical side to the issue of privacy with regard to personal locator service. The following is a citation from IEEE Spectrum Feb.2000 page 48: "Confidentiality of information about a person's whereabouts is a serious concern for location technology. Databases already store large amounts of personal information, including medical data, marketing preferences, and credit information. Lax security could lead to serious abuse of this data. Access to a database of location information could aggravate this situation by further exposing a persons movements. Moreover, it can have real-time implications. For example, someone could find and harm a victim. Obviously, technical and commercial considerations will determine the success of the technology. Issues of users' privacy and confidentiality will, however, have to be addressed first." We take on the privacy issues as a technical challenge in front of technological developments, not as an afterthought.

Researchers: Prof. Stig F. Mj°lsnes, PhD candidate Tord Reistad, Stud.techn. Tina Krekke.


  1. Stig F. Mjølsnes. A study of implementation aspects of GALILEO controlled access service.
    SINTEF Technical Report STF40 F00045, Trondheim, 15 May 2000. pdf-file
  2. S. F. Mjølsnes. Security of Access Service for GNSS.
    Proc. 4th European Workshop on Mobile and Personal Satellite Communications (EMPS 2000), Eds. Gardiner
    and Glover, Wiley 2000, pp. 185-190. ISBN 1857900774.
  3. Stig F. Mjølsnes. Conditional Access for Mobile Location-Aware Business.
    Proc. 14th International Technical Meeting of the Satellite Division of
    The Institute of Navigation ION GPS 2001, Salt Lake City , pages 2600-2611, September 2001. pdf-file
    (Yes, I was leaving Newark for Salt Lake City late night before 11. September!)
  4. Stig F. Mjølsnes and Børje Forssell. Galileo and location-based services. NORSIG-2001, Trondheim 18-20.oktober 2001. pdf-file
  5. Tina Hermandsen Krekke. Security Requirements of Location-Aware Mobile Services. Information Security Specialization Project, Dep. Telematics, NTNU. November 2003. pdf-file