Improving QoS Of WiMAX By On_Demand Bandwidth Allocation Based On PMP Mode

Abstract

<em>Abstract</em>—The bandwidth allocation in both wired and wireless networks has posed great challenges to network engineers for improving desirable Quality of Service (QoS), Bandwidth allocation is always an important element for improve QoS of network. Despite this, IEEE 802.16e-2005 does not have a bandwidth allocation algorithm or mechanism to support (worldwide interoperability for microwave access) WiMAX network presently. This includes both uplink (UL) and downlink (DL) directions. Thus, most of researches are focusing in this area. In order to improve the QoS of WiMAX demand, the total capacity of WiMAX system must be optimized. Thereby, in this research, a new bandwidth allocation mechanism for WiMAX network is proposed, called On Demand Bandwidth Allocation (ODBA). The proposed mechanism design has the management module in the Subscribe Station (SS), which is for management UL bandwidth, and one new module in the Base Station (BS). This includes UL/DL bandwidth allocation and service flow schedule. We tested the new mechanism by running in the simulation of OMNET++. As the results show that the ODBA mechanism has improve the scheduled probability (SP) and increase the throughput of WiMAX networ

Dual Threshold Scheduling for VoIP Traffic on Downlink of WiMAX Networks

“…The proposed scheme, namely, Queue-Length based Scheduling (QLS), monitors the instantaneous occupancy of n queues. The algorithm marks two thresholds on the queue, a minimum threshold, T min , and a maximum threshold, T max (Fig.1), just as RED [15] does. Suppose QL i is current queue size of flow i, where QL i ≧ 0, and i= 1, 2, …,n.…”

“…Slice-based scheduling usually involves in queue prioritization, flow queuing and the resources need to be reserved per slice basis. Such scheduling can be categorized into two classes: resource-based [11][12] and bandwidth-based [12][13][14][15]. Resource-based scheduling allocates a slice in terms of a fraction of the base station's resource slots per OFDMA frame.…”