The WiMAX network provides an efficient QoS to the large number of users. The real time and non-real time multimedia applications are gaining importance in the WiMAX network. To support such applications, there is a need to propose an efficient QoS of traffic prediction mechanism for the WiMAX networks. To address this, the authors have applied Gene Expression Programming technique for CBR based traffic and file transfer applications in the WiMAX network. The main focus of this chapter is to develop the mathematical expressions for throughput of the network by considering bandwidth, average end-to-end delay and average jitter as inputs for CBR based traffic and file transfer applications. This expression helps to analyze and predict the QoS of traffic of a given network. The simulation results show that the model values and the target values match with better approximation. Experimentally GEP performs better than other existing algorithms. Furthermore, sensitivity analysis has been carried out for both the applications
TopIntroduction
IEEE 802.16 air interface standard (Jeffrey et al., 2007) provides the details of physical layer and Media Access Control (MAC) layer of wireless communication system, which aims to build a multi-service network with Worldwide Interoperability for Microwave Access (WiMAX) technology. The different standards of WiMAX networks are IEEE 802.16a, IEEE 802.16d, IEEE 802.16e and IEEE 802.16j. There is a constant evolution of different standards, along with the demand for real-time multimedia applications such as Constant Bit Rate (CBR) based traffic, video stream and Voice over Internet Protocol (VoIP) and non-real-time multimedia applications such as file transfer, web browsing and email. To support these multimedia applications, the standards must be sensitive to the need for bandwidth with high speed access, large network coverage and the provision of good Quality of Services (QoS) to a large number of users.
The basic topology of a WiMAX network consists of two participating entities, called Base Station (BS) and Subscriber Station (SS). The BS is the central node, responsible for coordinating all the communication and providing connectivity to the SSs. The BS is the station that provides access to the public network. This network can be categorized into two operating modes: a mandatory Point-to-Multipoint (PMP) mode and an optional mesh mode. In PMP mode (Akashdeep et al., 2014; Ali et al., 2009), all SSs are only one-hop away from the BS and communicate to the BS directly in a centralized manner and not through other neighboring SSs. Akashdeep et al. (2014) have investigated on design issues for the development of schedulers and also ensured QoS support in WiMAX networks.I n optional mesh mode (Akyildiz et al., 2005; Kas et al., 2010), all SSs are one hop or more than one hop away from the BS and so the SSs communicates with the BS directly or indirectly (i.e. with other SSs) in a distributed manner. In literature (Sharma et al., 2014; Sharma et al., 2017), many researchers have worked on wireless mesh network. Due to the dynamic behavior of the wireless mesh network, handling routing is a critical issue. Sharma et al. (2017) have applied a nature inspired technique called Termite Colony Optimization (TCO) on this network. The TCO algorithm is used to find an optimal route based on the link cost. In this chapter, the researchers focus on a centralized PMP mode, which provides better QoS performance compared to distributed mesh mode (Ni et al., 2007).
There are two ways of providing QoS (Sekercioglu et al., 2009), they are user-centric QoS and network-centric QoS. The user-centric QoS comprises the degree of satisfaction of a user for the service. The network-centric QoS comprises the ability to control the mix of bandwidth, average end-to-end delay and average jitter in the network in order to deliver a network service such as CBR based traffic, file transfer application and VoIP. This chapter is primarily concerned with the network-centric QoS. The QoS parameters such as bandwidth, packet delivery ratio, average end-to-end delay, average jitter and throughput are generally used to measure the effect of multimedia streams on the level of QoS. These QoS parameters are considered only for the network-centric QoS, but not on the user-centric QoS. The WiMAX network (Carvalho et al., 2013) mainly depends on parameters such as bandwidth, delay, jitter, and throughput for efficient communication. This influences the QoS with a certain level of end-to-end quality for multimedia applications through the management of MAC and network layer for the provision of better QoS services.