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Radio connection management and signalling protocols for ATM via satellitesFan, Bin January 2000 (has links)
The increasing demand for broadband multimedia services and their extension to mobiles has spurred provision via satellites. This is because satellite systems can provide a truly global coverage that cannot be economically realised by either fixed wireline systems or terrestrial mobile systems. Most of next generation satellite systems proposed, such as Astrolink, SPACEWAY and SkyBridge, consider using ATM or ATM based technology over satellite to provide broadband services requiring mobility and higher bandwidth. This thesis therefore concerns future broadband satellite networks that use on-board processing and intersatellite links to extend the terrestrial ATM provision to worldwide satellite systems. This thesis discusses the air interface connection management and call handling schemes for integrated mobile/fixed ATM-satellite networks. The prime aim is to research an integrated solution that provides effective radio connection management and mobility support whilst maintaining the required QoS at both user terminals and gateway earth stations. We target at minimising the difference in performance between terrestrial ATM and ATM over satellite and providing mobility extension to the ATM protocols, whilst maintaining a high satellite channel efficiency and keeping as little as possible signalling modifications. In this thesis, an efficient radio connection management scheme, which is designed for a QoS-provisioning transport of ATM traffic over satellite links, and a mobility-enhanced signalling protocol scheme for mobile ATM-satellite networks are proposed. Another large proportion of this thesis is devoted to the optimisations of multiple access and logic link control because these are the major factors that effecting the performance within ATM- satellite integrated systems. As a result, a semi-permanent signalling protocol, a reliability- dependent Selective Repeat Automatic Repeat reQuest (SR ARQ) and an adaptive timer SR ARQ are proposed. In addition to the proposed connection management scheme, a reservation meta-signalling for setting up signalling connections at the user-network radio interface and a mobility-enhanced call handling protocol derived from Q.2931 are proposed. Call control functions such as call routing, location update, paging, handover and authentication are discussed as well. The proposed signalling protocol architecture provides a protocol reference model for ATM-satellite integrated systems. The verification and demonstration of the advantages of the semi-permanent signalling protocol, which offers a new method to improve the system channel efficiency on signalling connections, have been achieved. The proposed reliability-dependent SR ARQ protocol provides a novel approach to optimise the transmission throughput to support a variety of traffic types with different QoS requirements in ATM-satellite systems. The proposed connection management scheme effectively manages the air interface connections for ATM services through diversifying connection types, establishing QoS-based connections and deploying an efficient connection mapping and control scheme. The proposed radio connection management scheme together with the optimised Multiple Access Control (MAC) and ARQ provides a framework of interworking protocols for ATM over satellites. It can also find application in other similar systems that involve the integration of terrestrial protocols and mobile satellites. The research work that has been accomplished herein provides a solution and guidance to the design of signalling protocols for mobile satellite systems to implement ATM technology or indeed other future protocols.
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Improving low earth orbit digital communications by optimising CPFSK/MSK modulations in single band-limited UHF channels using DSP techniques on-board microsatellitesSun, Wei January 1995 (has links)
No description available.
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Traffic and congestion control for ATM over satellite to provide QoSOrs, Tolga January 1998 (has links)
In broadband multimedia satellite networks it is necessary to multiplex bursty streams of traffic with differing Quality of Service (QoS) requirements to maximise the utilisation of the satellite link bandwidth. Providing the desired QoS of each service, in a multi-service environment is a major challenge for satellite networks. Asynchronous Transfer Mode (ATM) which provides hard QoS guarantees is suitable for a multi-service satellite environment. ATM has been developed as a vehicle for multimedia communications and is widely regarded as one of the most important and fastest-growing communications technology of this decade. The design of suitable traffic and congestion control algorithms is one of the most important challenge for the success of an ATM-based satellite network. This thesis develops and optimises a traffic and congestion control mechanism which can provide users the required QoS for ATM over satellite networks. In order to provide QoS differentiation for end-to-end communication it is proposed to use both loss and delay priorities, which are determined form the required Cell Loss Rate (CLR) and Cell Transfer Delay (CTD) parameters, for each service class. A multiple shared buffer scheduling (MSBS) policy considering both delay and loss priorities, is proposed and evaluated for scheduling and discarding of ATM cells. It is shown that both the CTD and CLR requirements of ATM services can be met by the MSBS scheme. A combined preventive/reactive control scheme incorporating an adaptive Leaky Bucket (LB) is investigated for the satellite environment. It has been found that reactive control improves the cell loss due to congestion for time scales larger than the propagation delay. As the satellite air interface bandwidth is currently one of the most expensive commodities in the service provision, an adaptive MAC protocol that can support the ATM service classes whilst maximising the bandwidth utilisation, is proposed and evaluated. The mapping of ATM service classes to MAC classes and the use of a prioritised request queue provides the QoS differentiation required by ATM networks. It is shown that a pure reservation system performs poorly for very bursty user traffic. The user population which can be supported using Random Access (RA) for very bursty users with short burst duration is higher. The system throughput can be maximised, by making this protocol adaptive to changing traffic characteristics. It is shown that the utilisation of the frame capacity and the total number of users served can be improved by using this protocol.
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Network coding applications to high bit-rate satellite networksGiambene, G., Muhammad, M., Luong, D.K., Bacco, M., Gotta, A., Celandroni, N., Jaff, Esua K., Susanto, Misfa, Hu, Yim Fun, Pillai, Prashant, Ali, Muhammad, de Cola, T. January 2015 (has links)
No / Satellite networks are expected to support multimedia traffic flows, offering high capacity with QoS guarantees. However, system efficiency is often impaired by packet losses due to erasure channel effects. Reconfigurable and adaptive air interfaces are possible solutions to alleviate some of these issues. On the other hand, network coding is a promising technique to improve satellite network performance. This position paper reports on potential applications of network coding to satellite networks. Surveys and preliminary numerical results are provided on network coding applications to different exemplary satellite scenarios. Specifically, the adoption of Random Linear Network Coding (RLNC) is considered in three cases, namely, multicast transmissions, handover for multihomed aircraft mobile terminals, and multipath TCP-based applications. OSI layers on which the implementation of networking coding would potentially yield benefits are also recommended.
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Source mobility support for source specific multicast in satellite networksJaff, Esua K., Pillai, Prashant, Hu, Yim Fun January 2013 (has links)
No
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Network coding for multicast communications over satellite networksJaff, Esua K., Susanto, Misfa, Ali, Muhammad, Pillai, Prashant, Hu, Yim Fun January 2015 (has links)
No / Random packet errors and erasures are common in satellite
communications. These types of packet losses could become significant in
mobile satellite scenarios like satellite-based aeronautical communications
where mobility at very high speeds is a routine. The current adaptive coding
and modulation (ACM) schemes used in new satellite systems like the DVBRCS2
might offer some solutions to the problems posed by random packet
errors but very little or no solution to the problems of packet erasures where
packets are completely lost in transmission. The use of the current ACM
schemes to combat packet losses in a high random packet errors and erasures
environment like the satellite-based aeronautical communications will result in
very low throughput. Network coding (NC) has proved to significantly improve
throughput and thus saves bandwidth resources in such an environment. This
paper focuses on establishing how in random linear network coding (RLNC)
the satellite bandwidth utilization is affected by changing values of the
generation size, rate of packet loss and number of receivers in a satellite-based
aeronautical reliable IP multicast communication. From the simulation results,
it shows that the bandwidth utilization generally increases with increasing
generation size, rate of packet loss and number of receivers.
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Performance analysis of data aggregation and security in WSN-satellite integrated networksVerma, Suraj, Pillai, Prashant, Hu, Yim Fun January 2013 (has links)
No / Recently there has been an exponential rise in the use of Wireless Sensor Networks (WSNs) in various applications. While WSNs have been primarily used as independent networks, researchers are now looking into ways of integrating them with other existing networks. One such network is the satellite network which provides a reliable communication backbone to remote areas that lack appropriate terrestrial infrastructure. However, due to the integration of the two networks with different transmission and operational characteristics interoperability and security become major concerns. This paper presents an ns-2 based simulation framework of a WSN-satellite integrated network that is used to evaluate the effects of data aggregation and security mechanisms on overall network performance. The average end-to-end packet delay, overall energy consumption and aggregation efficiency are considered for this analysis. This paper also looks into the effects of implementing hop-by-hop security and end-to-end security and justifies the need for end-to-end security in the WSN-satellite integrated networks.
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Radio resource management for satellite UMTS : dynamic scheduling algorithm for a UMTS-compatible satellite networkXu, Kai January 2009 (has links)
The third generation of mobile communication systems introduce interactive Multicast and Unicast multimedia services at a fast data rate of up to 2 Mbps and is expected to complete the globalization of the mobile telecommunication systems. The implementation of these services on satellite systems, particularly for broadcast and multicast applications to complement terrestrial services is ideal since satellite systems are capable of providing global coverage in areas not served by terrestrial telecommunication services. However, the main bottleneck of such systems is the scarcity of radio resources for supporting multimedia applications which has resulted in the rapid growth in research efforts for deriving efficient radio resource management techniques. This issue is addressed in this thesis, where the main emphasis is to design a dynamic scheduling framework and algorithm that can improve the overall performance of the radio resource management strategy of a UMTS compatible satellite network, taking into account the unique characteristics of wireless channel conditions. This thesis will initially be focused on the design of the network and functional architecture of a UMTS -compatible satellite network. Based on this architecture, an effective scheduling framework is designed, which can provide different types of resource assigning strategies. A functional model of scheduler is defined to describe the behaviours and interactions between different functional entities. An OPNET simulation model with a complete network protocol stack is developed to validate the performance of the scheduling algorithms implemented in the satellite network. Different types of traffic are considered for the OPNET simulation, such as the Poisson Process, ONOFF Source and Self Similar Process, so that the performance of scheduling algorithm can be analyzed for different types of services. A novel scheduling algorithm is proposed to optimise the channel utilisation by considering the characteristics of the wireless channel, which are bursty and location dependent. In order to overcome the channel errors, different code rates are applied for the user under different channel conditions. The proposed scheduling algorithm is designed to give higher priority to users with higher code rate, so that the throughput of network is optimized and at the same time, maintaining the end users' service level agreements. The fairness of the proposed scheduling algorithm is validated using OPNET simulation. The simulation results show that the algorithm can fairly allocate resource to different connections not only among different service classes but also within the same service class depending on their QoS attributes.
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A connection admission control framework for UMTS based satellite systems : an adaptive admission control algorithm with pre-emption control mechanism for unicast and multicast communications in satellite UMTSPillai, Anju January 2011 (has links)
In recent years, there has been an exponential growth in the use of multimedia applications. A satellite system offers great potential for multimedia applications with its ability to broadcast and multicast a large amount of data over a very large area as compared to a terrestrial system. However, the limited transmission capacity along with the dynamically varying channel conditions impedes the delivery of good quality multimedia service in a satellite system which has resulted in research efforts for deriving efficient radio resource management techniques. This issue is addressed in this thesis, where the main emphasis is to design a CAC framework which maximizes the utilization of the scarce radio resources available in the satellite and at the same time increases the performance of the system for a UMTS based satellite system supporting unicast and multicast traffic. The design of the system architecture for a UMTS based satellite system is presented. Based on this architecture, a CAC framework is designed consisting of three different functionalities: the admission control procedure, the retune procedure and the pre-emption procedure. The joint use of these functionalities is proposed to allow the performance of the system to be maintained under congestion. Different algorithms are proposed for different functionalities; an adaptive admission control algorithm, a greedy retune algorithm and three pre-emption algorithms (Greedy, SubSetSum, and Fuzzy). A MATLAB simulation model is developed to study the performance of the proposed CAC framework. A GUI is created to provide the user with the flexibility to configure the system settings before starting a simulation. The configuration settings allow the system to be analysed under different conditions. The performance of the system is measured under different simulation settings such as enabling and disabling of the two functionalities of the CAC framework; retune procedure and the pre-emption procedure. The simulation results indicate the CAC framework as a whole with all the functionalities performs better than the other simulation settings.
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A Connection Admission Control Framework for UMTS based Satellite Systems.An Adaptive Admission Control algorithm with pre-emption control mechanism for unicast and multicast communications in satellite UMTS.Pillai, Anju January 2011 (has links)
In recent years, there has been an exponential growth in the use of
multimedia applications. A satellite system offers great potential for
multimedia applications with its ability to broadcast and multicast a large
amount of data over a very large area as compared to a terrestrial system.
However, the limited transmission capacity along with the dynamically
varying channel conditions impedes the delivery of good quality multimedia
service in a satellite system which has resulted in research efforts for deriving
efficient radio resource management techniques. This issue is addressed in
this thesis, where the main emphasis is to design a CAC framework which
maximizes the utilization of the scarce radio resources available in the
satellite and at the same time increases the performance of the system for a
UMTS based satellite system supporting unicast and multicast traffic.
The design of the system architecture for a UMTS based satellite system is
presented. Based on this architecture, a CAC framework is designed
consisting of three different functionalities: the admission control procedure,
the retune procedure and the pre-emption procedure. The joint use of these
functionalities is proposed to allow the performance of the system to be
maintained under congestion. Different algorithms are proposed for different
functionalities; an adaptive admission control algorithm, a greedy retune
algorithm and three pre-emption algorithms (Greedy, SubSetSum, and
Fuzzy).
A MATLAB simulation model is developed to study the performance of the
proposed CAC framework. A GUI is created to provide the user with the
flexibility to configure the system settings before starting a simulation. The
configuration settings allow the system to be analysed under different
conditions.
The performance of the system is measured under different simulation
settings such as enabling and disabling of the two functionalities of the CAC
framework; retune procedure and the pre-emption procedure. The simulation
results indicate the CAC framework as a whole with all the functionalities
performs better than the other simulation settings.
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