Informatics Publishing Limited

K. M. Rajasekaran ¹, S. Tamilselvan ²

Affiliations
1 Department of ECE, Adhiyamaan College of Engineering, Hosur, IN
2 Department of ECE, Pondicherry Engineering College, Pondicherry, IN

Abstract

The emerging broadband wireless access technology based on IEEE 802.16 is one of the most promising solutions to provide ubiquitous wireless access to the broadband service at low cost and is being actively promoted by the Worldwide Interoperability for Microwave Access (WiMAX) Forum: an industry-led consortium. Based on the IEEE 802.16, WiMAX can support a very high capacity, wide area mobility, and multimedia services with different traffic characteristics and various quality-of-service (QoS) requirements. This paper proposes an efficient uplink bandwidth request allocation algorithm for real-time services in Mobile WiMAX networks based on IEEE 802.16e. In order to minimize bandwidth wastage without degrading quality of service, the algorithm introduces a notion of target delay and dual feedback approach. The proposed algorithm calculates the amount of bandwidth request such that the delay is regulated around the desired level to minimize delay violation and delay jitter for extended real-time services. Also, it can increase utilization of wireless channel by making use of dual feedback, where the bandwidth request is adjusted based on the information about the backlogged amount of traffic in the queue and the rate mismatch between packet arrival and service rates. Due to the target delay and dual feedback, the proposed scheme can control delay and allocate bandwidth efficiently while satisfying QoS requirement. The performance is evaluated in terms of queue regulation, rate adaptation, delay controllability, and robustness to traffic characteristics. Finally, the performance of optimal bandwidth allocation is compared for extended real-time services and real-time services in mobile WiMAX networks.

Keywords

Mobile WiMAX Networks, IEEE 802.16, Uplink Scheduling, Bandwidth Request, Quality of Service, Real-Time Service.

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S. Tamilselvan ¹, R. Madhivanan ², K. M. Rajasekaran ³

Affiliations
1 Department of ECE, Pondicherry Engineering College, Pondicherry, IN
2 Department of ECE, Christ College of Engineering and Technology, Pondicherry, IN
3 Department of ECE, Adhiyamaan College of Engineering, Hosur, IN

Abstract

Wireless network refers to any type of computer network that is wireless, and is commonly associated with a telecommunications network whose interconnections between nodes are implemented without the use of wires. To accommodate various features of wireless networks, the 2D uplink and downlink wireless CAC problems are decomposed into two independent 1D CAC. To formulate the 1D CAC optimizations, the demands of service providers and subscribers are jointly taken into consideration. To solve the optimization problem, a utility and fairness-constrained optimal revenue policy and corresponding approximation algorithm is developed. Optimal utility and optimal revenue were obtained by using fairness constrained greedy algorithm. The average revenue and the blocking probability were determined. In order to compare the performance of different traffic arrival rate the utility and fairness constrained optimal revenue algorithm has been implemented. Simulation results are presented to demonstrate the effectiveness of the proposed wireless approach.

Keywords

Call Admission Control (CAC), Optimization, Orthogonal Frequency-Division Multiple Access (OFDMA), Time-Division Duplex (TDD).

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