Different queuing policies for handover requests in low Earth orbit mobile satellite systems (original) (raw)
Related papers
Queuing of handover requests in low earth orbit mobile satellite systems
1996
This paper deals with a study on resource management strategies in Low Earth Orbit Mobile Satellite Systems (LEO-MSSs). A suitable mobility model has been proposed. Fixed Channel Allocation (FCA) has been considered. Moreover, we have foreseen that inter-beam handover requests, which do not immediately find service, can be queued in order to reduce the handover failure rate. An analytical approach has been developed to compare two different queuing disciplines and its results have been compared with simulations.
Performance Analysis of Correlated Handover Service in LEO Mobile Satellite Systems
IEEE Communications Letters, 2016
Analytical models for low earth orbit mobile satellite systems (LEO-MSSs) should consider service time correlation in adjacent satellite spot beams. This work presents a simple analytical framework for the efficient performance evaluation of new and handover services in LEO-MSSs with correlated service times. When the fading channel is temporally correlated, channel characteristics in the preceding and succeeding spot beams do not change dramatically especially for services with short transmission times. A closed form solution of the correlated queue service time is derived using probability generating functions (PGFs) whose moments are used to derive the blocking probabilities of handover and new services. The system is then modeled as a queuing system with correlated service time and its performance investigated. The analytical results are validated by simulations. Typical numerical results are presented and their implications on the system performance discussed.
IEEE Transactions on Vehicular Technology, 1998
It is anticipated that the satellite component of the future universal mobile telecommunications system (UMTS) will be based (partly or totally) on non-GEOstationary (non-GEO) constellations of satellites to serve mixed populations of users, each category being treated through different contracts stipulating different quality of service (QoS). In particular, we envisage a high-quality premium service which guarantees the success of each handover procedure, called guaranteed handover (GH) service, and a low-cost lower quality service called regular service, where handover failures are accepted provided that the probability of a call being unsuccessful does not exceed a given value. This paper proposes a strategy which eliminates forced call terminations due to handover failures, thus allowing the GH service. This procedure applies to low earth orbit (LEO) constellations using the satellite-fixed cell technique. An analytical model has been derived to calculate QoS parameters for a mixed population of GH and regular users. Providing both GH service to some users and regular service to other users requires an increased satellite capacity with respect to the case where all the users are served with the regular service; this capacity increase has been evaluated as a function of the percentage of GH users, the traffic load per cell, and the considered satellite mobility environment. The GH approach has been validated through the comparison with another scheme which envisages the queuing of handover requests for privileged users.
A time-based reservation scheme for managing handovers in satellite systems
International Journal of Network Management, 2003
This paper proposes a Time-based Channel Reservation Algorithm (TCRA) suitable for managing handover and call admission control procedures in future mobile satellite systems. These systems are characterized by a high rate of handover attempts which can degrade significantly their performance. Therefore, we propose TCRA, a scheme which guarantees a null handover failure probability by managing the channel through a reservation strategy in the cells to be crossed by the user. Based on the feature that the satellite motion is predictable and deterministic, the scheme tries to maximize the channel utilization and enables the system to handle the most important number of users. The performance of the TCRA scheme has been examined by simulations and compared to the Guaranteed Handover (GH) scheme. The results show the behaviour of the algorithm and its performance.
Advance handovers arrangement and channel allocation in LEO satellite systems
Seamless Interconnection for Universal Services. Global Telecommunications Conference. GLOBECOM'99. (Cat. No.99CH37042)
Due to the high mobility nature of the Low Earth Orbit (LEO) satellite systems, satellite's coverage area changes with time causing extremely frequent handover rate. Therefore handover procedure has a significant impact on the success of LEO systems and handover failure rate is a major criterion in measuring system's performance. In this paper we propose a handover procedure called Advance Handovers Arrangement and Channel Allocation (AHACA) to maximally exploit the deterministic and predictable characteristics of LEO systems to reduce handover failures and optimize channel utilization. This method does not exclusively guard channels for handovers, instead it queues and reserves channels that are currently in use but will be released within expected queuing time.
Efficient Dynamic Channel Allocation Techniques with Handover Queuing for Mobile Satellite Networks
IEEE Journal on Selected Areas in Communications, 1995
Efficient dynamic channel allocation techniques with handover queuing suitable for applications in mobile satellite cellular networks, are discussed. The channel assignment on demand is performed on the basis of the evaluation of a suitable cost function. Geostationary and low earth orbit (LEO) satellites have been considered. In order to highlight the better performance of the dynamic techniques proposed, a performance comparison with a classical fixed channel allocation (FCA) has been carried out, as regards the probability that a newly arriving call is not completely served. It has also been shown that a higher traffic density, with respect to GEO systems, is manageable by means of LEO satellites.
Satellite handover techniques for LEO networks
International Journal of Satellite Communications and Networking, 2004
Low earth orbit (LEO) satellite constellations could play an important role in future mobile communication networks due to their characteristics, such as global coverage and low propagation delays. However, because of the non-stationarity of the satellites, a call may be subjected to handovers, which can be cell or satellite handovers. Quite many techniques have been proposed in the literature dealing with the cell handover issue. In this paper, a satellite handover procedure is proposed, that investigates and exploits the partial satellite diversity (namely, the existing common coverage area between contiguous satellites) in order to provide an efficient handover strategy, based always on a tradeoff of the blocking and forced termination probabilities for a fair treatment of new and handover calls. Three different criteria were examined for the selection of a satellite. Each one of them could be applied either to new or handover calls, therefore we investigated nine different service schemes. A simulation tool was implemented in order to compare the different service schemes and simulation results are presented at the end of the paper.
Handover Priority Schemes for Multi-Class Traffic in LEO Mobile Satellite Systems
2012
In this paper, an analytical framework is developed to evaluate the performance of complete sharing (CS) with two different handover priority schemes for multi-class traffic in Low Earth Orbit-Mobile Satellite Systems (LEO-MSS). In the first priority scheme, the handover requests are given the higher priority using queuing scheme with also taking into consideration the priority between classes of traffic. Where, in the second priority scheme a combination of guard channel and queuing of handover requests scheme is developed.
Satellite selection scheme for reducing handover attempts in LEO satellite communication systems
International Journal of Satellite Communications, 1998
Low earth orbit (LEO) satellite communication systems perform frequent intersatellite handovers for both fixed and mobile users. This paper proposes a satellite selection scheme for new/handover call requests when two or more satellites can be seen simultaneously. Each satellite in this scheme has a non-uniform transmitter antenna gain according to its relative position inside the coverage area. The antenna gain is proportional to the residual distance in the satellite's direction of movement and it compensates for the difference in path losses between satellite links. The residual distance distribution of the selected satellite and the mean number of intersatellite handovers during a call connection are calculated and compared with the results based on conventional methods. The proposed scheme can reduce the intersatellite handover call attempt rate without increasing system load and terminal complexity. Furthermore, this scheme can be extended to reduce both intersatellite and interbeam handover call attempt rates in a multiple spot beam environment. Especially, the average number of intersatellite and interbeam handovers during a call can be significantly reduced by using a hybrid algorithm with the proposed non-uniform power transmission scheme.
Dynamic time-based handover management in LEO satellite systems
Electronics Letters, 2007
In this letter, a handover scheme tailored for LEO satellite systems is proposed and evaluated. The proposed algorithm capitalizes upon the deterministic topology of this type of systems in order to increase channel utilization and diminish both blocking and forced termination probabilities.