This dissertation focuses on Quality of Service (QoS) support in the Worldwide Interoperability for Microwave Access (WiMAX), or IEEE 802.16e standard, and in its integration with Gigabit Ethernet Passive Optical Network (GEPON) to become which is called GEPON and WiMAX integration network. In wireless domain, WiMAX is a broadband access technology which satisfies substantial increase in demand for high speed and ubiquitous Internet access. In optical domain, GEPON is a promising fiber-based access technique which is expected to provide a cheap solution to broadband access due to the ubiquitous deployment of Ethernet-based network equipment. Therefore, the integrated WiMAX and GEPON network can take advantage of the bandwidth benefit of fiber communications, and the mobile and non-line-of-sight benefits of wireless communications. This integration network enables fixed and mobile convergence and is expected to significantly reduce overall design and operation costs of new-generation broadband access networks.
In the GEPON and WiMAX convergence network, throughput and Quality of Service (QoS) in term of end-to-end delay are the most important performance metrics. In the scope of this dissertation, we focus on the QoS support for the converged GEPON and WiMAX network.
In the WiMAX and GEPON convergence network, the communications between Mobile Subscribers Stations (MSSs) or Subscriber Stations (SS) are still purely the communications between original users in WiMAX. For WiMAX, energy management in order to extend the lifetime of MSS so that the WiMAX can support mobility is the most important issue, because the energy of mobile device mainly depends on battery. In WiMAX, the energy saving objective is done by employing sleep-mode operations in MSS. However, the reduction of energy consumption results in unacceptable frame response delay or jitter which can be unacceptable for many delay sensitive applications, such as voice and video conference services, interactive video,… Therefore, not only energy consumption but also frame response delay are the most important network performance metrics. Unfortunately, WiMAX and previous studies about it did not pay adequate attention the importance of frame response delay. Therefore, in this dissertation, we propose several algorithms which find the optimal parameters in sleep-mode operations to guarantee QoS in terms of frame response delay while minimizing energy consumption. Our proposed algorithms are supported by numerical analysis and validated by simulation experiments.
In summary, this dissertation first proposes a QoS architecture for the convergence GEPON and WiMAX networks. With our proposed architecture, the integrated networks support Quality of Service for several traffic classes in sense that the traffic class with higher priority experiences lower end-to-end delay compared to the one with lower priority. In addition, the proposed architecture simplifies the network complexity, processing overhead, and so on. Then, to guarantee the QoS for the communications between MSSs, which is purely communications in WiMAX, we propose several algorithms to find the optimal parameters in sleep-mode operation. Our proposed algorithms ensure that the QoS in term of frame response delay or jitter is guaranteed while the energy consumption is minimized. Although the proposed algorithms are directly applied in WiMAX, they are also applicable in WiMAX and GEPON integration network since the convergence network contains WiMAX and the communications between MSSs in the convergence network is purely the communications within WiMAX.
