Significant technological advances are taking place in recent years in the areas of palm-sized computers and wireless communications, accompanied by an infiltration of the Internet in all aspects of our lives. Mobile Internet access accounts today for only a tiny proportion of the Internet users even though the number of mobile users greatly exceeds the number of Internet-users . However, it is forecasted that as early as 2003 almost half of the Internet population will consist of mobile access devices . By that time, a variety of different wireless network platforms with different properties, capable of transporting Internet traffic will be available . In addition, the turn of operators towards license-free frequencies  and their eventual congestion will lead to the realisation of alternative dynamic network structures, namely Internet compatible, multi-hop, ad-hoc networks.
Consequently, a technology that allows the integration of available heterogeneous and homogenous networks into a single platform capable of supporting user roaming between them, while not interrupting active communications , will gain importance. This development will be assisted by the rise of new mobile devices capable of maintaining various access interfaces that will allow simultaneous connectivity over a range of providers and technologies . Internally, such devices will be able to distinguish between networks with individual properties and intelligently determine on a per flow basis, the most appropriate network. Finally, the emergence of a plethora of access devices will dictate the liberation of users from a single device (i.e. mobile phone) and allow mobility between devices even as the user is communicating.
The rapid growth of the mobile Internet user base has not been accompanied by an equivalent evolution in the corresponding products and services for mobile customers. Such services and the underlying technical means for their realisation currently suffer from a lack of mobility awareness  as well as context awareness . This is due to the fact that existing mechanisms do not maintain the capacity to adapt to changes in the user’s position and orientation. It is understood that such services can only be realised through assistance from mechanisms whereby the user’s location in the physical world can be determined. However, the evaluation of this information is rarely enough for the resolution of service discovery services. That is mostly because there is no direct correspondence between the virtual and physical space. As such, when discovering local network resources the question arises as to what extent these resources are also physically local or closer than others available in other networks. This question becomes all the more important when integrated network platforms are brought into scope.

Keryer, P. (2000), Presentation at the workshop: Visions of the Wireless World, 12th December 2000, Brussels
  European Telework Online, WWW-site (12.12.2000), http://www.eto.org.uk/eito
  Niebert, N, “Convergence of Cellular and Broadband Networks towards Future Wireless Generations”, In Wireless Strategic Initiative (WSI) Book of Visions 2000 - Visions of the Wireless World Workshop, Brussels 2000
  Mohr, W., “Alternative Vorschläge zur Spektrumsnutzung für IMT-2000/UMTS”, Spektrumsworkshop ITU-R, October 2000, Geneva, Switzerland
  Fikouras, N.A., Görg, C., Fikouras, I, “Achieving Integrated Network Platforms through IP”, In: Proceedings of the Wireless World Research Forum (WWRF) Kick-off meeting, Munich 2001, Germany
  Katz, HR, Brewer, AE, “The Case for Wireless Overlay ‘Networks”, In: SPIE Multimedia and Networking Conference (MMNC’96),  January1996, San Jose, CA, USA
  Fikouras, I., Wunram, M., Weber, F., “Seamless Integration of Mobile Products and Services – User-centricity and Mobility Awareness for mCommerce”, In: Proceedings of the Wireless World Research Forum (WWRF) Kick-off meeting, Munich 2001, Germany

Assuming that mobile users will constantly and seamlessly vary their access network with respect to their location, cost, network or other conditions, locating services can become a challenging task. Current solutions attempt to bypass the aforementioned problem by deploying a centralised entity that is responsible for resolving the service requests for a given group of users . As such, independently of the mobile user’s access network, the centralised Directory Agent (DA) is always reachable. However, such solutions completely disregard the mobile property of future integrated network platforms and by abandoning a distributed organisation eventually restrict their own capacity. A distributed organisation approach to the problem of service location can have several advantages including localised management, faster access, faster updates and correspondence with the physical world.
For systems such as the ones presented complexity will be unacceptable. Service Discovery services will have to be navigated with a user friendly manner providing to the End-User an overview of services available in the Internet or within their physical reach. In environments with the potential for true global user centred mobility, communication services will further approach users providing solutions to problems of every day life. Specifically, new services will emerge that will enable users to locate resources and services within their physical and network environment.

Project daypath, WWW-site (22.3.2001),  http://www.jentro.com/en/solutions/daypath/index.html