The Experts below are selected from a list of 2412 Experts worldwide ranked by ideXlab platform
Qing-an Zeng - One of the best experts on this subject based on the ideXlab platform.
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Performance analysis of the IEEE 802.11e wireless networks with TCP ACK prioritization
Telecommunication Systems, 2010Co-Authors: Aruna Thangaraj, Qing-an ZengAbstract:With the advent of multimedia over wireless local area networks, the IEEE 802.11e standard was proposed to incorporate Quality of Service (QoS). It has been found that the throughput of Transmission Control Protocol (TCP) is less than that of User Datagram Protocol (UDP) in the IEEE 802.11e. This is because the TCP acknowledgment packets are queued up at the access points. In this paper, two types of TCP acknowledgment prioritizing schemes are proposed. The proposed schemes improve the overall throughput of TCP while maintaining the QoS requirements. We also analyze the problem of starvation of Lower Priority Traffic and its effects on the performance of Lower Priority TCP Traffic. The proposed dynamic scheme of TCP acknowledgment prioritization aims at improving the throughput of the Lower Priority TCP Traffic under heavy network load while maintaining the QoS requirements of the higher Priority Traffic. The schemes have been verified through extensive simulation.
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Performance analysis of the IEEE 802.11e wireless networks with TCP ACK prioritization
Telecommunication Systems, 2010Co-Authors: Aruna Thangaraj, Qing-an ZengAbstract:With the advent of multimedia over wireless local area networks, the IEEE 802.11e standard was proposed to incorporate Quality of Service (QoS). It has been found that the throughput of Transmission Control Protocol (TCP) is less than that of User Datagram Protocol (UDP) in the IEEE 802.11e. This is because the TCP acknowledgment packets are queued up at the access points. In this paper, two types of TCP acknowledgment prioritizing schemes are proposed. The proposed schemes improve the overall throughput of TCP while maintaining the QoS requirements. We also analyze the problem of starvation of Lower Priority Traffic and its effects on the performance of Lower Priority TCP Traffic. The proposed dynamic scheme of TCP acknowledgment prioritization aims at improving the throughput of the Lower Priority TCP Traffic under heavy network load while maintaining the QoS requirements of the higher Priority Traffic. The schemes have been verified through extensive simulation.
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Resource Allocation Schemes in Integrated Heterogeneous Wireless and Mobile Networks
Journal of Networks, 2007Co-Authors: Wei Shen, Qing-an ZengAbstract:Wireless and mobile networks have experienced a great success in the past few years. However, any single type of wireless and mobile network cannot meet all types of service requirements. For example, no single type of existing wireless and mobile network can provide both wide coverage and high bandwidth services. In order to provide more comprehensive services, an integrated heterogeneous wireless and mobile network is introduced. It consists of several different types of wireless and mobile networks and can provide more connection options for mobile users than a single type of wireless and mobile network. However, the integrated heterogeneous wireless and mobile network imposes great challenges in many perspectives. One of these challenges is to efficiently allocate resource for supporting multiple Traffic (voice, video, data, and etc). Although a lot of resource allocation schemes have been proposed, they mostly focus on supporting multiple Traffic in single type of network or supporting a single type of Traffic in an integrated heterogeneous wireless and mobile network. Therefore, they may not be suitable for supporting multiple Traffic in an integrated heterogeneous wireless and mobile network. In this paper, we propose two preemption -based resource allocation schemes to support multiple Traffic in an integrated heterogeneous wireless and mobile network. In both schemes, we allow different types of Traffic to have different priorities and higher Priority Traffic can preempt Lower Priority Traffic. We evaluate the system performances of our proposed schemes by using extensive simulations. The simulation results show that the proposed schemes can significantly improve the system performances.
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ITNG - Two Novel Resource Management Schemes for Integrated Wireless Networks
Fourth International Conference on Information Technology (ITNG'07), 2007Co-Authors: Wei Shen, Qing-an ZengAbstract:Although a lot of resource management schemes have been proposed to support multiple Traffic in wireless networks, they mostly focused on a single wireless network, such as cellular network. In order to provide more comprehensive services, an integrated wireless network is introduced which consists of several different types of wireless networks and provides more connection options for mobile users than a single wireless network. However, it also imposes a great challenge to efficiently utilize the resources, where existing resource management schemes may not be suitable. In this paper, we propose two resource management schemes to support multiple Traffic in an integrated wireless network. In these two schemes, higher Priority Traffic can preempt Lower Priority Traffic. The system performances are evaluated and compared with one existing scheme by extensive simulations. The simulation results show that the proposed schemes can significantly improve the system performances
Joberto S. B. Martins - One of the best experts on this subject based on the ideXlab platform.
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ISCC - Routing in DS-TE networks with an opportunistic bandwidth allocation model
2012 IEEE Symposium on Computers and Communications (ISCC), 2012Co-Authors: Rafael F. Reale, Walter Da C. P. Neto, Joberto S. B. MartinsAbstract:DS-TE (DiffServ-aware MPLS-TE) networks support Quality of Service (QoS) implementation for Traffic classes (TCs). Bandwidth Allocation Models (BAMs) are used in DS-TE networks in order to define Bandwidth Constraints (BCs) in a per-class basis and effectively define how this resource is reserved and eventually shared by applications. Existing BAM models are aware of Traffic classes and are enablers for QoS guarantees while trying to optimize the use of bandwidth resources on a per-link basis. This paper proposes a new bandwidth allocation model (AllocTC-Sharing) which has an opportunistic behavior on a per-link basis. Opportunistic behavior means that AllocTC-Sharing allows higher Priority Traffic classes to use non-allocated resources of Lower Priority Traffic classes and the other way around. The paper presents initially the AllocTC-Sharing and its integration with CSPF (Constrained Shortest Path First) routing protocol for end-to-end MPLS LSP (Label Switched Path) path setup. Then, we compare AllocTC-Sharing features with RDM (Russian Dolls Model) and Adapt-RDM models. The results show that AllocTC-Sharing preserves the features of RDM and Adapt-RDM and improves overall network utilization.
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AllocTC-Sharing: A New Bandwidth Allocation Model for DS-TE Networks.
2011 7th Latin American Network Operations and Management Symposium, 2011Co-Authors: Rafael F. Reale, Walter Da C. P. Neto, Joberto S. B. MartinsAbstract:DiffServ-aware MPLS-TE (DS-TE) allows bandwidth reservation for Traffic Classes (TCs) in MPLS-based engineered networks and, as such, improves the basic MPLS-TE model. In DS-TE networks, per-Class quality of service guarantees are provided while being possible to achieve improved network utilization. DS-TE requires the use of a Bandwidth Allocation Model (BAM) that establishes the amount of bandwidth per-Class and any eventual sharing among them. This paper proposes a new bandwidth allocation model (AllocTC-Sharing) in which the higher Priority Traffic classes are allowed to use non allocated resources of Lower Priority Traffic classes and vice versa. By adopting this dual sense allocation strategy for dynamic bandwidth allocation, it is shown that AllocTC-Sharing model preserves bandwidth constraints for Traffic classes and improves overall link utilization.
T. Agarwal - One of the best experts on this subject based on the ideXlab platform.
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Dynamic tuning of the maximum contention window (CWmax) for enhanced service differentiation in IEEE 802.11 wireless ad-hoc networks
IEEE 60th Vehicular Technology Conference 2004. VTC2004-Fall. 2004, 1Co-Authors: L. Gannoune, Stephan Robert, N. Tomar, T. AgarwalAbstract:The proposed IEEE 802.11e draft standard defines new MAC protocols for QoS in wireless networks, mainly EDCF and HCF. In this paper, we propose to extend EDCF with a dynamic adaptation algorithm of the maximum contention window (CWmax) that enables each station to tune the size of the CWmax used in its back-off algorithm at run time. The purpose of our scheme is to reduce delay and jitter and increases the efficiency of the transmission channel. Priorities between access categories are provisioned by updating the size of the CWmax according to application requirements and channel conditions. The performance of the enhanced EDCF are extensively investigated by simulation. Results obtained indicate that the delay and jitter for high Priority Traffic, i.e., audio Traffic, improve and delay decreases by up to 43%. Furthermore, delay for Lower Priority Traffic, e.g., video Traffic, remains stable. Throughput in CWmax adaptation, compared to EDCF, is stable in light and medium system load and increases by up to 7% especially at high system load.
Deniz Gurkan - One of the best experts on this subject based on the ideXlab platform.
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Channel preemptive EDCA for emergency medium access in distributed wireless networks
IEEE Transactions on Wireless Communications, 2009Co-Authors: Manikanden Balakrishnan, Driss Benhaddou, Xiaojing Yuan, Deniz GurkanAbstract:The foray of wireless networks into time-sensitive applications demands support for emergency services, with guaranteed QoS bounds. The IEEE 802.11e technology could be an attractive option for emergency networking, if the protocol design is enhanced to achieve deterministic QoS for emergency Traffic during distributed network operation. We propose channel preemptive EDCA scheme, an in-channel service preemption methodology for the 802.11e EDCA framework where emergency Traffic incorporates the privileges to preempt the services of Lower Priority Traffic for better QoS guarantees. The CP-EDCA results for emergency frames depict up to 50% decrease in medium access delays and insensitivity to routine Traffic competition.
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Service preemptions for guaranteed emergency medium access in Wireless Sensor Networks
MILCOM 2008 - 2008 IEEE Military Communications Conference, 2008Co-Authors: Manikanden Balakrishnan, Driss Benhaddou, Xiaojing Yuan, Deniz GurkanAbstract:Wireless Sensor Networks (WSNs) recently find extensive applications in remote disaster and health monitoring, where Traffic prioritization is extremely essential for timely dissemination of critical information to the first responders. Though several resource control standards exist for general wireless networks, supporting differentiated Traffic services (Quality-of-Service (QoS)) at the Medium Access Control layer for sensor networks need exclusive investigation and significant improvements. Particularly, the network treatment for disaster or medical emergencies needs to be exclusive (deterministic guarantees) rather than probabilistic guarantees as in most wireless QoS standards. In this paper, we introduce channel service preemptions during random medium access in WSNs. In the context of time-critical sensor applications, emergency Traffic will have the privileges to interrupt the services of other routine Traffic in the network to guarantee the lowest possible channel access latencies. We design our methodology within the QoS framework of the popular 802.11e EDCA standard and demonstrate the importance of service preemptions for emergency reporting. The performance analysis predicts close to 50% uniform decrease in emergency medium access delays when using our Channel Preemptive-EDCA (CP-EDCA) as compared to EDCA. The results also depict that CP-EDCA guarantees the lowest delay bounds and immunity to the presence of other Lower Priority Traffic, for emergency frames, even under high network loads. The cost, however, is increased delays for routine Traffic, which is acceptable during emergency sensor reporting.
Goutam Das - One of the best experts on this subject based on the ideXlab platform.
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Low Complexity Fair Scheduling in LTE/LTE-A Uplink Involving Multiple Traffic Classes
IEEE Systems Journal, 2020Co-Authors: Atri Mukhopadhyay, Goutam DasAbstract:The bulk of the research on Long Term Evolution/Long Term Evolution-Advanced packet scheduling is concentrated in the downlink and the uplink is comparatively less explored. In up-link, channel aware scheduling with throughput maximization has been widely studied while considering an infinitely back-logged buffer model, which makes the investigations unrealistic. Therefore, we propose an optimal uplink packet scheduling pro-cedure with realistic Traffic sources. Firstly, we advocate a joint channel and buffer aware algorithm, which maximizes the actual transmitted bit-count. Thereafter, we introduce delay constraints in our algorithm to support real-time Traffic. We further enhance our algorithm by incorporating the varied delay and throughput requirements demanded by mixed Traffic classes. Finally, we in-troduce Priority flipping to minimize bandwidth starvation of Lower Priority Traffic in presence of higher percentage of high Priority Traffic. We observe that a delay constraint may render the optimization-based proposals infeasible. Therefore, to avoid infeasibility, we replace the delay constraint with delay outage minimization (DOM). DOM aims at minimizing the packet drop due to delay violation. Moreover, DOM also helps in reducing the problems to a well-known assignment problem, which can be solved by applying the Hungarian algorithm. Hence, our approach delivers an optimal allocation with low computational complexity.
