Behcet Sarikaya

Supporting node mobility using mobile IPv6 in a LEO-satellite network

This paper investigates supporting IPv6, the next generation IP in a Teledesic-like low earth orbit (LEO) satellite backbone. The network architecture consists of LEO satellites with intersatellite links, gateway stations, standard terminals and mobile terminals. This network offers mobile data services like earth cellular networks. Due to its enlarged addressing space, IPv6 is selected as the network layer. For routing IPv6 datagrams in this network, a tunnelling approach is taken in which IPv6 datagrams from/to the Internet are fragmented/reassembled into ATM-cell-like packets. To route these packets inside the LEO-constellation, we design a unicast link-state routing algorithm in which the responsibilities for routing are shared between the satellites and gateway stations. For user mobility, Mobile IPv6 extended for paging the users in standby mode is used. The paper concludes with a presentation of simulation results.

Location Based Services

We defined a generic architecture with which geographic location of mobile devices can be determined. The architecture includes wireless base stations, a location server and GPS satellites. Location-based services that can be offered to people carrying mobile devices include emergency services such as enhanced 911, high value asset tracking systems and commercial services such as location-based advertisements. Several LBS prototypes have been developed in the universities and research centers. The location of the mobile devices in these prototypes can be accessed using different wireless access technologies. An application programming interface and databases must be designed to enable the development of different types of applications using real-time absolute location data. Standardized APIs and architectures are required to access the location data from cellular networks. We described the example of CDMA2000 cellular networks and the example API called mobile location protocol developed by the location interoperability forum (LIF).