Browsing by Author "Al-Begain, K."
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Item Open Access Buffer Management for Multimedia QoS Control over HSDPA Downlink(IEEE, 2007-08-27) Yerima, Suleiman; Al-Begain, K.HSDPA specifications include support for a flexible framework for QoS management. In this paper, it is shown how buffer management could be incorporated into HSDPA QoS framework for 'multimedia' traffic QoS control in the MAC-hs of the Node-B. A time-space-priority (TSP) scheme is proposed as viable buffer management scheme to this effect. Comparative simulation study with other schemes is presented, demonstrating the effectiveness of the TSP buffer management scheme for 'multimedia' service QoS control in HSDPA Node-B data buffers.Item Open Access Dynamic Buffer Management for Multimedia QoS in Beyond 3G Wireless Networks(IAENG, 2009-11-19) Yerima, Suleiman; Al-Begain, K.This paper investigates a dynamic buffer management scheme for QoS control of multimedia services in beyond 3G wireless systems. The scheme is studied in the context of the state-of-the-art 3.5G system i.e. the High Speed Downlink Packet Access (HSDPA) which enhances 3G UMTS to support high-speed packet switched services. Unlike earlier systems, UMTS-evolved systems from HSDPA and beyond incorporate mechanisms such as packet scheduling and HARQ in the base station necessitating data buffering at the air interface. This introduces a potential bottleneck to end-to-end communication. Hence, buffer management at the air interface is crucial for end-to-end QoS support of multimedia services with multiplexed parallel diverse flows such as video and data in the same end-user session. The dynamic buffer management scheme for HSDPA multimedia sessions with aggregated real-time and non real-time flows is investigated via extensive HSDPA simulations. The impact of the scheme on end-to-end traffic performance is evaluated with an example multimedia session comprising a real-time streaming flow concurrent with TCP-based non real-time flow. Results demonstrate that the scheme can guarantee the end-to-end QoS of the real-time streaming flow, whilst simultaneously protecting the non real-time flow from starvation resulting in improved end-to-end throughput performance.Item Open Access Dynamic Buffer Management for Multimedia Services in 3.5 G Wireless Networks(IEEE, 2009-07) Yerima, Suleiman; Al-Begain, K.This paper presents and investigates a dynamic buffer management scheme for QoS control of multimedia services in a 3.5 G wireless system ie the High Speed Downlink Packet Access (HSDPA). HSDPA was introduced to enhance UMTS for high-speed packet switched services. With HSDPA, packet scheduling and HARQ mechanisms in the base station require data buffering at the air interface thus introducing a potential bottleneck to end-to-end communication. Hence, for multimedia services with multiplexed parallel diverse flows such as video and data in the same end-user session, buffer management schemes in the base station are essential to support end-to-end QoS provision. We propose a dynamic buffer management scheme for HSDPA multimedia sessions with aggregated real-time and non real-time flows in the paper. The end-to-end performance impact of the scheme is evaluated with an example multimedia session comprising a real-time streaming flow concurrent with TCP-based non real-time flow via extensive HSDPA simulations. Results demonstrate that the scheme can guarantee the end-to-end QoS of the real-time streaming flow, whilst simultaneously protecting non real-time flow from starvation resulting in improved end-to-end throughput performance.Item Open Access A Dynamic Buffer Management Scheme for End-to-End QoS Enhancement of Multi-flow Services in HSDPA(IEEE, 2008-09-16) Yerima, Suleiman; Al-Begain, K.End-user multi-flow services support is a crucial aspect of current and next generation mobile networks. This paper presents a dynamic buffer management strategy for HSDPA end-user multi-flow traffic with aggregated real-time and non-real-time flows. The scheme incorporates dynamic priority switching between the flows for transmission on the HSDPA radio channel. The end-to-end performance of the proposed strategy is investigated with an end-user multi-flow session of simultaneous VoIP and TCP-based downlink traffic using detailed HSDPA system-level simulations. Compared to an equivalent static buffer management scheme, the results show that end-to-end throughput performance gains in the non-real-time flow and better HSDPA channel utilization is attainable without compromising the real-time VoIP flow QoS constraints.Item Open Access End-to-End QoS Improvement of HSDPA End-User Multi-Flow Traffic Using RAN Buffer Management(IEEE, 2008-11) Yerima, Suleiman; Al-Begain, K.High speed downlink packet access (HSDPA) was introduced to UMTS radio access segment to provide higher capacity for new packet switched services. As a result, packet switched sessions with multiple diverse traffic flows such as concurrent voice and data, or video and data being transmitted to the same user are a likely commonplace cellular packet data scenario. In HSDPA, radio access network (RAN) buffer management schemes are essential to support the end-to-end QoS of such sessions. Hence in this paper we present the end-to-end performance study of a proposed RAN buffer management scheme for multi-flow sessions via dynamic system-level HSDPA simulations. The scheme is an enhancement of a time-space priority (TSP) queuing strategy applied to the node B MAC-hs buffer allocated to an end user with concurrent real-time (RT) and non-real-time (NRT) flows during a multi-flow session. The experimental multi- flow scenario is a packet voice call with concurrent TCP-based file download to the same user. Results show that with the proposed enhancements to the TSP-based RAN buffer management, end-to-end QoS performance gains accrue to the NRT flow without compromising RT flow QoS of the same end user session.Item Embargo Investigation of the M2/G2/1/∞, N queue with restricted admission of priority customers and its application to HSDPA mobile systems(Elsevier, 2009-06-11) Yerima, Suleiman; Al-Begain, K.; Dudin, A.; Kazimirsky, A.This paper investigates a queuing system for QoS optimization of multimedia traffic consisting of aggregated streams with diverse QoS requirements transmitted to a mobile terminal over a common downlink shared channel. The queuing system, proposed for buffer management of aggregated single-user traffic in the base station of High-Speed Downlink Packet Access (HSDPA), allows for optimum loss/delay/jitter performance for end-user multimedia traffic with delay-tolerant non-real-time streams and partially loss tolerant real-time streams. In the queuing system, the real-time stream has non-preemptive priority in service but the number of the packets in the system is restricted by a constant. The non-real-time stream has no service priority but is allowed unlimited access to the system. Both types of packets arrive in the stationary Poisson flow. Service times follow general distribution depending on the packet type. Stability condition for the model is derived. Queue length distribution for both types of customers is calculated at arbitrary epochs and service completion epochs. Loss probability for priority packets is computed. Waiting time distribution in terms of Laplace-Stieltjes transform is obtained for both types of packets. Mean waiting time and jitter are computed. Numerical examples presented demonstrate the effectiveness of the queuing system for QoS optimization of buffered end-user multimedia traffic with aggregated real-time and non-real-time streams.Item Open Access Novel Radio Link Buffer Management Schemes For End-user Multi-class Traffic in High Speed Packet Access Networks(Springer, 2010-05-29) Yerima, Suleiman; Al-Begain, K.The requirement to provide multimedia services with QoS support in mobile networks has led to standardization and deployment of high speed data access technologies such as the High Speed Downlink Packet Access (HSDPA) system. HSDPA improves downlink packet data and multimedia services support in WCDMA-based cellular networks. As is the trend in emerging wireless access technologies, HSDPA supports end-user multi-class sessions comprising parallel flows with diverse Quality of Service (QoS) requirements, such as real-time (RT) voice or video streaming concurrent with non real-time (NRT) data service being transmitted to the same user, with differentiated queuing at the radio link interface. Hence, in this paper we present and evaluate novel radio link buffer management schemes for QoS control of multimedia traffic comprising concurrent RT and NRT flows in the same HSDPA end-user session. The new buffer management schemes—Enhanced Time Space Priority (E-TSP) and Dynamic Time Space Priority (D-TSP)—are designed to improve radio link and network resource utilization as well as optimize end-to-end QoS performance of both RT and NRT flows in the end-user session. Both schemes are based on a Time-Space Priority (TSP) queuing system, which provides joint delay and loss differentiation between the flows by queuing (partially) loss tolerant RT flow packets for higher transmission priority but with restricted access to the buffer space, whilst allowing unlimited access to the buffer space for delay-tolerant NRT flow but with queuing for lower transmission priority. Experiments by means of extensive system-level HSDPA simulations demonstrates that with the proposed TSP-based radio link buffer management schemes, significant end-to-end QoS performance gains accrue to end-user traffic with simultaneous RT and NRT flows, in addition to improved resource utilization in the radio access network.Item Embargo Performance Evaluation and Resource Management of Hierarchical MACRO-/MICRO Cellular Networks using MOSEL-2(Springer, 2007-09-06) Yerima, Suleiman; Al-Begain, K.; Zriekat, A. I.The paper presents a performance evaluation and resource management of hierarchical MACRO-/MICRO cellular networks using the new Modeling and Evaluation Language (MOSEL-2). MOSEL-2 with new constructs has the ability to find the performance and reliability modeling and evaluation of systems with exponential and non-exponential distributions. A MACRO/MICRO cell structure is solved numerically and mathematically in this paper to handle the handoff calls. Additionally, a simulation program is written to validate these results. In order to reduce the loss probability, a guard channels are introduced at the MICRO cell and channel reservation at the MACRO cell. Additionally, the concept of queuing is introduced where there is a possibility for the handoff calls from both MACRO and MICRO layers to be queued when all the resources are occupied. MOSEL-2 is used to find the numerical solution for this problem with both exponential and general exponential (GE) distribution. The performance analysis show the efficiency of the proposed scheme to manage the handoff calls and the ability of the suggested scheme to reduce the blocking probability of handover calls and the loss probability as the main objective is to block the new connection rather than terminating the ongoing connection as well as balancing the load all over the whole network. It is shown in this paper that there are a set of important factors that affect the performance, such as: reservation policy, channel allocation, handover ratio, capacity of the queue and the variation of the inter-arrival times. These factors are discussed via some important performance measures, such as: new call blocking probability, blocking probability of handover calls, loss probability, utilization and the average delay of the queue.Item Open Access Performance modelling of a queue management scheme with rate control for HSDPA(2007-06) Yerima, Suleiman; Al-Begain, K.High Speed Downlink Packet Access (HSDPA) is being increasingly deployed to enhance UMTS Radio Access Networks. Scheduling of Node B (base station) buffered user data for transmission over a shared radio channel is a key HSDPA functionality which enables queue management techniques to be utilized to improve QoS provisioning for mixed ‘multimedia’services. Thus, we have previously proposed and studied a Time-Space Priority (TSP) buffer management scheme for ‘multimedia’QoS control in HSDPA Node B. In this paper the scheme is extended to incorporate a threshold-based rate control mechanism which provides flow control between the RNC and Node B entities over the Iub interface to improve the QoS performance of non-real-time (NRT) streams in the multimedia flow. Mathematical and simulation models are developed for comparative analysis with the previously studied TSP scheme lacking rate control. The results demonstrate the performance improvement achievable with the joint implementation of TSP queue management scheme and Iub flow control mechanism(s).