An integrated voice and data multiple-access scheme for a land-mobile satellite system (original) (raw)
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Voice over IP service and performance in satellite networks
IEEE Communications Magazine, 2001
Voice over IP services have recently emerged as a low-cost alternative to PSTN voice service, and an attractive solution for voice/data integration in public and private networks. Satellite systems, as an integral part of the global communications infrastructure, already have an increasing portion of their capacities used to carry data packets, and with their global coverage and reach to remote areas are well positioned to enable growth of VoIP services. For VoIP over satellite, several issues need to be addressed. These include transmission and quality of service issues, as well as service-related issues such as service creation and customization, support of IN and supplementary services, and seamless integration with the PSTN. While the service-related aspects of VoIP are common to both terrestrial and satellite networks, transport-related issues are different. This article reports performance results of laboratory experiments for evaluating VoIP over satellite under different link and traffic conditions. To avoid congestion which will lead to a large number of packets being dropped in routers and result in a severe degradation of voice quality, care should be taken to ensure that the link loading level does not exceed the link capacity.
1998
The Universal Mobile Telecommunications System (UMTS) will provide multimedia services to users in whatever environment via uniform service access procedures. Efficient Medium Access Control (MAC) protocols are needed to guarantee high capacity. This paper deals with Packet Reservation Multiple Access (PRMA), an efficient MAC protocol that has been widely studied in terrestrial microcellular systems. We investigate the suitability of PRMA for supporting voice and data transmissions in a UMTS based on Low Earth Orbit -Mobile Satellite Systems (LEO-MSSs). It is shown here that, through a suitable choice of the system parameter values, the PRMA protocol may achieve a good quality of service also in LEO-MSSs.
2008
⎯ High expense of satellite channels along with providing telephony services for rural regions makes us to propose a new Medium Access Control (MAC) protocol for sending signaling of telephony traffic via geo stationary satellite with narrow bandwidth channels. This paper explores an efficient MAC protocol, Slot Reservation Demand Assignment Multiple Access (SRDAMA), and also examines its performance via ns-2.31 simulator. It is notable that for simulation of this scheme some changes has been made to C++ codes of ns-2.31. To best of our knowledge no previous work has studied the problem of transmitting telephony traffic signaling over narrow bandwidth geo satellite channel.
1996
This paper will discuss some of the challenges in connecting mobile satellite users and mobile terrestrial users in a cost efficient manner and with a grade of service comparable to that of satellite to fixed user calls. IssLIes arising from the translation between the mobility management protocols resident at the satellite earth station and those resident at cellular switches-either GSM (Group{ "Special Mobile) or 1S-41 (used by U.S. di~ital cellular, systems) type-will bc discussed. The impact of GM call routing procedures cm the call setup of a satellite to roaming GSM user will be described. Challenges facing provision of seamless call handoff between satellite and cellular systems will be given. A summary ,of the issues explored in the paper ,Z'%j, artfrlisted and future w&k outlinecl.
PERFORMANCE STUDY OF AN INTEGRATED SATELLITE/TERRESTRIAL MOBILE COMMUNICATION SYSTEM
International Journal of Satellite Communications, 1996
Terrestrial cellular networks and mobile satellite systems are expected to converge towards a future integrated satellite/terrestrial mobile communication network. Besides a system globalization, the integration of terrestrial and satellite mobile systems will lead to the unloading of the fixed part of the mobile network. This paper proposes an integrated satellite/terrestrial mobile communication system and evaluates its performance in terms of the blocking probability for new call attempts, the call dropping probability and the probability of unsuccessful call. This communication system was simulated and its performence compared with that of a stand-alone terrestrial mobile system. In the terrestrial part of the system we have considered fixed channel allocation (FCA) and dynamic channel allocation (DCA) techniques. Satellite channels can have equal or lower priority compared to terrestrial channels. The improvement of the system performance by means of satellite-to-terrestrial handovers was also estimated.
IEEE Transactions on Wireless Communications, 2002
Mobile satellite systems (MSSs) are expected to play a significant role in providing users with communication services worldwide. In such context, low earth orbit (LEO) satellite constellations seem to be a good solution to attain a global coverage and to allow the use of low-power lightweight mobile terminals. This paper analyzes the performance of a novel medium access control (MAC) scheme suitable for applications in LEO-MSSs, named Packet Reservation Multiple Access with Hindering States (PRMA-HS), that has been derived by proper modifications of the well-known PRMA protocol. We envisage a mixed traffic with voice sources and data sources with different quality of service (QoS) requirements. The good behavior of the proposed PRMA-HS scheme is validated by extensive comparisons with the classical PRMA protocol. Finally, it is shown here that PRMA-HS efficiently supports integrated voice and data traffics in LEO-MSSs. Index Terms-Mobile satellite systems, multiple access, network architectures and protocols.
IEE Proceedings - Communications, 1996
Different dynamic channel allocation (DCA) approaches based on the evaluation of a cost function are proposedl. The scenario considered is low earth orbit :and geostationary orbit mobile satellite systcnis. A suitable user mobility model has bcen defined to generate interbeam handover requests. Different alternatives to manage interbeaim handovers have been investigated. Among them, the most promising sohtion seems to be the queuing of handover requests. The quality of service parameters 1.hat have been considered are: blocking probability for new call arrivals, handover failure probability arid the probability of incompletcly served call owing to the initial blocking or to the failure of a subsequent handover request. Comparisons among the proposed DCA techniques and the fixed channel allocation technique have been (carried out to find a solution 1.hat represents a good trade-off between the blocking performance and the required signalling load.
Delay bounds for voice over IP calls transported over satellite access networks
Mobile Networks and …, 2002
Whether or not voice calls of traditional quality can be supported between 2 users connected to an IP backbone via satellite access systems depends largely on the mouth-to-ear delay, an important part of which is consumed by the satellite networks themselves. In this paper, a methodology is developed to calculate upper bounds for the latter delay component as a function of the used codec, the experienced packet loss ratio, the echo levels at both sides of the connection and the chosen voice packet size. Illustrations are provided.
thesis on call blockage using satellite channels.pdf
The mobile communication (GSM) technology makes use of frequency resources (channels or trunks) as a means of providing the necessary service for its users. Due to limited availability of communication channels, it is practically difficult or impossible to make uninterrupted voice calls during peak (busy) hour(s). This study addresses and explores way of mitigating call blockage in GSM network operations with a view to enhance service delivery to subscribers. Data from the Operational Maintenance Centre of the network operator (AIRTEL Nig. Ltd) were obtained and used to determine the grade of service of the network operator, as well as validate the need for the integration of satellite channels to mitigate call blockage. A suitable markov chain model was adapted and the effect of grade of service of the network operation and call lost probability were simulated using Matlab. The grade of service calculated for GMS operation revealed that the probability of blockage ranges from 4% to 16%, which is relative high compared to the 2% internationally accepted standard. However, with the integration of satellite channels with the terrestrial GSM channels, a reduction in call blockage is noticed as much as 3%. The improvement in the communication throughput makes the integration of satellite channels with the terrestrial GSM channels a viable option.