Intersegment Handover Research Articles

Intersegment handover performance in integrated terrestrial satellite systems

AbstractTo achieve a global cellular network, integration among segments offering different coverage (indoor, outdoor and global) must be pursued. Of course, the possibility to hold the call switching among different segments must be guaranteed. Hence, efficient algorithms to perform intersegment handover (ISHO) must be implemented.The paper aims at analysing some ISHO procedures developed in the frame of some European projects and other proposed in the literature, in a scenario with satellite and terrestrial segments interworking to achieve a worldwide cellular coverage.Performance evaluation will be carried out for different system configurations utilizing a dynamic satellite constellation simulator in the time domain. The impact of the distance user‐gateway on performance will be addressed. For each procedure, the execution delay and its complementary cumulative distribution have been evaluated for different constellation geometries at different distances from the gateway. Copyright © 2002 John Wiley & Sons, Ltd.

Performance evaluation of an optimized intersegment handover procedure for hybrid constellation satellite systems

AbstractSatellite system architectures based on geostationary or Low Earth Orbit (LEO)/Medium Earth Orbit (MEO) constellation suffer from their intrinsic limitations in terms of coverage or flexibility. Traffic requirements concerning broadband services are expected to be very uneven both in time and space. To match this requirement and to improve coverage an innovative satellite system architecture, composed of a LEO/MEO segment to complement a Geostationary Earth Orbit (GEO) segment, has been proposed. In this scenario, to achieve interworking and to make it possible to hold the call while switching between the two segments, efficient intersegment handover (ISHO) procedures must be identified.The paper, after introducing the classical ISHO schemes, aims at defining and analysing an ISHO procedure developed to perform handover in case of hybrid constellations based on the use of both GEO and LEO/MEO orbits. Performance evaluation will be carried out for different system configurations utilizing a dynamic satellite constellation simulator in the time domain. The execution delay and its complementary cumulative distribution have been evaluated for different constellation geometry at different distances from the gateway. Copyright © 2002 John Wiley & Sons, Ltd.

Efficient Integration of IP-Based Terrestrial and Satellite Systems: ARQTechniques and Inter-Segment Handover

A satellite communication system is an excellent candidate to provide broadband integrated Internet services to globally scattered users. The inter-operation between a satellite system and the existing terrestrial Internet infrastructure introduces new challenges at different layers. Automatic Repeat reQuest (ARQ) techniques have been introduced at radio link layer to improve the performance of Transport Control Protocol (TCP)/IP over wireless terrestrial links, but these techniques are usually dismissed in presence of high latency links such as satellite links. In this paper, we will show that a truncated power control can effectively improve the trade-off delay-residual error after retransmissions and makes ARQ techniques a feasible solution for error control in satellite links. Furthermore, mobility management issues in presence of satellite diversity are addressed. Performance of an Inter-Segment Hand-Over (ISHO) procedure, in terms of propagation delay, will be carried out through simulation for different space segment configurations.

Intersegment handover between terrestrial and satellite segments: analysis and performance evaluation through simulation

In future generation communication systems, integration among different segments (terrestrial indoor, terrestrial outdoor and satellite) will be necessary if aiming at providing real global and contiguous coverage without interruption. To achieve integrated or interworking systems efficient algorithms to perform intersegment handover (ISHO) must be implemented. In this way, the switching among different segments can occur without dropping of the call. The paper aims at analyzing some ISHO procedures developed in the frame of some European projects and at evaluating their performance for different system configurations utilizing a dynamic constellation simulator in the time domain. On the basis of the above procedures, aiming at optimizing resources, a new procedure is proposed and analyzed. For each procedure the execution delay and its range of variation have been evaluated for different constellation geometry. Finally, a performance comparison among the various procedures is shown.

Performance of intersegment handover protocols in an integrated space/terrestrial-UMTS environment

The universal mobile telecommunications system (UMTS) will deliver a convergent network incorporating cellular, cordless, wireless local loop, and satellite technologies. A signaling protocol for intersegment handover (ISHO) in an integrated space/terrestrial-UMTS environment is presented. After discussing a number of possible ISHO scenarios, backward mobile-assisted handover (HO) incorporating signaling diversity is chosen as the most appropriate ISHO scheme. Based on the generic radio-access network (GRAN) concept and by using a satellite-UMTS network architecture and functional model, the derivation of an ISHO protocol is presented. The performance of this protocol is analyzed and evaluated in terms of the service interruption time, execution signaling time, and the end-to-end signaling time. Simulation results show that, in agreement with the GRAN concept, the service interruption time is independent of the signaling protocol and depends only on the satellite round-trip delay and the radio interface characteristics. The interarrival rate of the ISHO requests affect the performance of the protocol only when the value of the mean service time is increased. However, even in such a situation, the performance of the protocol is still considered acceptable.