Efficient bandwidth management to quality-of-service in broadband wireless access networks

A prerequisite to provide multimedia services over Broadband Wireless Access (BWA) networks is to have provisions of new mechanisms that allow such networks to treat traffic as per their limitations and performance bounds. These new mechanisms need to be a part of what is called a QoS management. We propose several admission control schemes that support QoS for multimedia services in BWA networks. The basic strategy of the first scheme is to look at the actual demand of bandwidth determined by both arrival rate and required transmission rate for each class of traffic. The second scheme provides the highest priority for Unsolicited Granted Service (UGS) flows and maximizes the bandwidth utilization by bandwidth borrowing and degradation. We develop an analytical model to evaluate the system performance of second scheme. The traffic associated with real-time Polling Service (rtPS), non real-time Polling Service (nrtPS), Best Effort (BE) demonstrates self-similarity or fractal nature due to their significant rate variability. Therefore, based on the actually traffic characteristics and using Gaussian model for aggregated traffic in large network with Chernoff bound method, we obtain an upper bound for the blocking probability above the packet level of all types of traffic in 802.16 Wireless Metropolitan Area Network (WirelessMAN). In addition, it is critical for the subscriber station to know the channel state at the receiver and optimally schedule the transmission. A periodical handshake is proposed to probe the channel state. As improper selection of handshake interval wastes retransmission bandwidth of corrupted packets, we introduce a mathematical model so as to determine an optimal handshake interval. Furthermore, the wireless channel is classified into three different channel states and a BER based adaptive bandwidth allocation scheme is proposed. Multi-channel, multi-radio, multi-hop, and infrastructure-based Wireless Mesh Network is expected to have a wireless backhaul to enable ubiquitous Internet connectivity to a large number of mobile users for simultaneous video, voice and data communications. As a result, providing higher network capacity has become a fundamental issue in designing and deploying such networks. Therefore, the per user capacity of wireless mesh networks is also analyzed in this dissertation. Keywords. Broadband Wireless Access (BWA), IEEE 802.16 WirelessMAN, WiMAX, Quality-of-Service (QoS), Bandwidth Management, Admission Control, Error Prone Channel, Optimal Probing, Adaptive Bandwidth Allocation, Capacity, Wireless Mesh Network (WMN)