The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Vikram Krishnamurthy - One of the best experts on this subject based on the ideXlab platform.
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optimal joint session admission control in integrated wlan and cdma cellular networks with vertical handoff
IEEE Transactions on Mobile Computing, 2007Co-Authors: F Yu, Vikram KrishnamurthyAbstract:This paper considers optimizing the utilization of radio resources in a heterogeneous integrated system consisting of two different networks: a wireless local area network (WLAN) and a wideband code division multiple access (CDMA) network. We propose a joint session admission control scheme for Multimedia Traffic that maximizes overall network revenue with quality of service (QoS) constraints over both the WLAN and the CDMA cellular networks. The WLAN operates under the IEEE 802.11e medium access control (MAC) protocol, which supports QoS for Multimedia Traffic. A novel concept of effective bandwidth is used in the CDMA network to derive the unified radio resource usage, taking into account both physical layer linear minimum mean square error (LMMSE) receivers and characteristics of the packet Traffic. Numerical examples illustrate that the network revenue earned in the proposed joint admission control scheme is significantly larger than that when the individual networks are optimized independently with no vertical handoff between them. The revenue gain is also significant over the scheme in which vertical handoff is supported, but admission control is not done jointly. Furthermore, we show that the optimal joint admission control policy is a randomized policy, i.e., sessions are admitted to the system with probabilities in some states
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cross layer optimal connection admission control for variable bit rate Multimedia Traffic in packet wireless cdma networks
IEEE Transactions on Signal Processing, 2006Co-Authors: Vikram Krishnamurthy, Victor C M LeungAbstract:Next generation wireless code division multiple access (CDMA) networks are required to support packet Multimedia Traffic. This paper addresses the connection admission control problem for multiservice packet Traffic modeled as Markov modulated Poisson process (MMPP) with the quality of service (QoS) requirements on both physical layer signal-to-interference ratio (SIR) and network layer blocking probability. Optimal linear-programming-based algorithms are presented that take into account of SIR outage probability constraints. By exploiting the MMPP Traffic models and introducing a small SIR outage probability, the proposed algorithms can dramatically improve the network utilization. In addition, we propose two reduced complexity algorithms that require less computation and can have satisfactory approximation to the optimal solutions. Numerical examples illustrating the performance of the proposed schemes are presented.
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cross layer optimal connection admission control for variable bit rate Multimedia Traffic in packet wireless cdma networks
Global Communications Conference, 2004Co-Authors: Vikram Krishnamurthy, Victor C M LeungAbstract:Next generation wireless code division multiple access (CDMA) networks are required to support packet Multimedia Traffic. This paper addresses the connection admission control problem for multi-service packet Traffic, modeled as a Markov modulated Poisson process (MMPP) with the quality of service (QoS) requirements on both physical layer signal-to-interference (SIR) and network layer blocking probability. Optimal linear-programming-based algorithms are presented that take into account SIR outage probability constraints. By exploiting the MMPP Traffic models and introducing a small SIR outage probability, the proposed algorithms can dramatically improve the network utilization. Numerical examples illustrating the performance of the proposed schemes are presented.
Kiseon Kim - One of the best experts on this subject based on the ideXlab platform.
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a wireless Multimedia lan architecture using dcf with shortened contention window for qos provisioning
Wireless Communications and Networking Conference, 2003Co-Authors: Kanghee Kim, Aftab Ahmad, Kiseon KimAbstract:In this paper, we propose a MAC architecture for IEEE 802.11-like WLANs supporting Multimedia services. The main characteristics of the proposed MAC procedure are the period restriction and DCF/SC (distributed coordination function with shortened contention-windows) instead of the PCF (point coordination function) of the IEEE 802.11 standards. We investigate the performance of the proposed MAC mechanism in terms of utilization, throughput, latency and jitter under two Multimedia network environments considered by the IEEE 802.11-task group E. These environments are home and enterprise. In the simulated performance, this novel approach, which preserves the Traffic classification but increases the channel utilization, thus guarantees QoS (quality of service) of Multimedia Traffic.
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a wireless Multimedia lan architecture using dcf with shortened contention window for qos provisioning
IEEE Communications Letters, 2003Co-Authors: Kanghee Kim, Aftab Ahmad, Kiseon KimAbstract:We propose a medium access control (MAC) architecture for IEEE 802.11-like WLANs supporting Multimedia services. The novel access algorithm, maintaining a Diffserv-like Traffic classification, shows a remarkable improvement in all performance measures of the Multimedia Traffic, especially in heavy load situation.
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capacity plane of cdma system for Multimedia Traffic
Electronics Letters, 1997Co-Authors: Jeongrok Yang, Yeongyoon Choi, Jeehwan Ahn, Kiseon KimAbstract:In a wireless CDMA system for Multimedia services, the maximum number of concurrent users satisfying the QoS requirements is evaluated in both single-cell and multi-cell environments. A simple upper-bounded hyperplane concept is also formulated to visualise the capacity of a Multimedia CDMA system. With this capacity plane, the tradeoffs between the level of system resources needed for a certain user and that needed for others are illustrated, analytically, within the concept of resource management.
Victor C M Leung - One of the best experts on this subject based on the ideXlab platform.
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cross layer optimal connection admission control for variable bit rate Multimedia Traffic in packet wireless cdma networks
IEEE Transactions on Signal Processing, 2006Co-Authors: Vikram Krishnamurthy, Victor C M LeungAbstract:Next generation wireless code division multiple access (CDMA) networks are required to support packet Multimedia Traffic. This paper addresses the connection admission control problem for multiservice packet Traffic modeled as Markov modulated Poisson process (MMPP) with the quality of service (QoS) requirements on both physical layer signal-to-interference ratio (SIR) and network layer blocking probability. Optimal linear-programming-based algorithms are presented that take into account of SIR outage probability constraints. By exploiting the MMPP Traffic models and introducing a small SIR outage probability, the proposed algorithms can dramatically improve the network utilization. In addition, we propose two reduced complexity algorithms that require less computation and can have satisfactory approximation to the optimal solutions. Numerical examples illustrating the performance of the proposed schemes are presented.
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cross layer optimal connection admission control for variable bit rate Multimedia Traffic in packet wireless cdma networks
Global Communications Conference, 2004Co-Authors: Vikram Krishnamurthy, Victor C M LeungAbstract:Next generation wireless code division multiple access (CDMA) networks are required to support packet Multimedia Traffic. This paper addresses the connection admission control problem for multi-service packet Traffic, modeled as a Markov modulated Poisson process (MMPP) with the quality of service (QoS) requirements on both physical layer signal-to-interference (SIR) and network layer blocking probability. Optimal linear-programming-based algorithms are presented that take into account SIR outage probability constraints. By exploiting the MMPP Traffic models and introducing a small SIR outage probability, the proposed algorithms can dramatically improve the network utilization. Numerical examples illustrating the performance of the proposed schemes are presented.
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effects of mobility on packet level performance of connection oriented Multimedia Traffic over packet switched cellular networks
Wireless Communications and Networking Conference, 2004Co-Authors: Victor C M LeungAbstract:Packet level metrics such as buffer overflow probability and packet delay are very important quality of service (QoS) parameters in future cellular mobile networks supporting packet-switched Traffic. In this paper, we study the effects of user mobility on packet level performance of QoS provisioning schemes for connection-oriented Multimedia Traffic, which is modeled by a fluid model with on/off sources. We consider both the tradition mobility model, in which channel holding times for new and handoff calls are identically distributed, and a new mobility model proposed recently, in which they are exponentially distributed but with different average values. Using these models, we analyze the packet level performance, such as buffer overflow probability and packet average delay, of different QoS provisioning schemes. Using numerical examples, we show that user mobility models have significant impacts on the packet level performance. The discrepancy between the buffer overflow probabilities using different user mobility models can be as large as 20 times.
Kanghee Kim - One of the best experts on this subject based on the ideXlab platform.
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a wireless Multimedia lan architecture using dcf with shortened contention window for qos provisioning
Wireless Communications and Networking Conference, 2003Co-Authors: Kanghee Kim, Aftab Ahmad, Kiseon KimAbstract:In this paper, we propose a MAC architecture for IEEE 802.11-like WLANs supporting Multimedia services. The main characteristics of the proposed MAC procedure are the period restriction and DCF/SC (distributed coordination function with shortened contention-windows) instead of the PCF (point coordination function) of the IEEE 802.11 standards. We investigate the performance of the proposed MAC mechanism in terms of utilization, throughput, latency and jitter under two Multimedia network environments considered by the IEEE 802.11-task group E. These environments are home and enterprise. In the simulated performance, this novel approach, which preserves the Traffic classification but increases the channel utilization, thus guarantees QoS (quality of service) of Multimedia Traffic.
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a wireless Multimedia lan architecture using dcf with shortened contention window for qos provisioning
IEEE Communications Letters, 2003Co-Authors: Kanghee Kim, Aftab Ahmad, Kiseon KimAbstract:We propose a medium access control (MAC) architecture for IEEE 802.11-like WLANs supporting Multimedia services. The novel access algorithm, maintaining a Diffserv-like Traffic classification, shows a remarkable improvement in all performance measures of the Multimedia Traffic, especially in heavy load situation.
P R Kumar - One of the best experts on this subject based on the ideXlab platform.
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characterization and optimization of delay guarantees for real time Multimedia Traffic flows in ieee 802 11 wlans
IEEE Transactions on Mobile Computing, 2016Co-Authors: Yan Gao, Chee Wei Tan, Ying Huang, Zheng Zeng, P R KumarAbstract:Due to the rapid growth of real-time applications and the ubiquity of IEEE 802.11 MAC as a layer-2 protocol for wireless local area networks (WLANs), it becomes increasingly important to support delay-based quality of service (QoS) in such WLANs. In this paper, we develop a simple and accurate enough analytical model for predicting the queueing delay of real-time Multimedia Traffic flows in non-homogeneous random access based WLANs. This leads to tractable analysis for meeting queueing delay specifications of a number of flows. In particular, we address the feasibility problem of whether the mean delays required by a set of User Datagram Protocol (UDP) flows supporting real-time Multimedia Traffic can be guaranteed in WLANs. Based on the model and feasibility analysis, we further develop an optimization technique to minimize the delays for the Traffic flows. Moreover, we present a decentralized algorithm and report its implementation and present extensive simulation and experimental trace-based results to demonstrate the accuracy of our model and the performance of the algorithms.