Efficient uplink scheduling policy for variable bit rate traffic in IEEE 802.16 BWA systems

Abstract

One of the major challenges in the context of transmitting real-time multimedia data in broadband wireless access (BWA) systems is that the varied bit rate of traffic causes low bandwidth utilization. The conventional uplink scheduling algorithms for variable bit rate (VBR) video traffic transmission in IEEE 802.16 BWA systems have some disadvantages, including waste of uplink bandwidth, MAC overhead, and access delay. To cope with these difficulties, we propose an uplink scheduling algorithm for VBR traffic transmission for IEEE 802.16 BWA systems. In the proposed algorithm, the base station (BS) assigns uplink bandwidth to the video user by considering the traffic state transitions. The uplink bandwidth is equally divided into several intervals where each interval represents a traffic state. Only when the traffic state is changed, the bandwidth request process is incurred. Also, by using two reserved bits in the generic MAC header of IEEE 802.16 BWA systems as piggyback bits, the information about traffic state transition can be sent to the BS without extra overhead. Simulations conducted with QualNet 4.0 show that the bandwidth waste ratio of our proposed algorithm is less than that of the conventional algorithms. That is, the proposed algorithm outperforms the conventional algorithms for VBR traffic transmission in IEEE 802.16 BWA systems in terms of bandwidth utilization.

GI/Geom/1 queue based on communication model for mesh networks

“…They modeled the multi-hop wireless networks as classic G/G/1 queuing networks. It was observed that data requirements in WMNs are mainly for Internet accesses [20,[23][24][25][26][27][28][29][30][31][32][33][34][35]. Jamieson and Balakrishnan [6] modeled gateway nodes as independent M/D/1 queue stations.…”

Scheduling model and performance analysis in transport mapping layer of control element in forwarding and control element separation system

“…In recent years, with the development of wireless networks, more scheduling algorithms satisfied that guarantee QoS were introduced [25][26][27][28][29][30]. There is no literature to introduce the performance analysis of GPS and SP two-stage scheduling.…”

A novel MAC protocol for IDMA‐based multi‐beam satellite communication systems

“…Here, we consider the system to provide three types of QoS for heterogeneous traffic, according to the application requirements: (i) bounded packet‐delivery delay; (ii) guaranteed transmission rate; and (iii) BER. Table summarizes the classification of heterogeneous traffic . Thus, three typical traffic models are supported in our systems. Conversational Model : Conversational class is constant bit rate under an on/off activity model. Streaming Model : Streaming class is variable bit rate modeled as a discrete‐state continuous time Markov process shown in Figure .…”