QoS Management in Heterogeneous Wireless Networks

• Main Authors: Ming-Chiao Chen, 陳明僑
• Other Authors: Jiann-Liang Chen
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/drkj52

博士 === 國立東華大學 === 資訊工程學系 === 96 === Abstract There has been a tremendous growth in wireless network technologies over the past decade. Wireless infrastructure has been deployed to complement and expand the wired infrastructure. There are many options available for users who want to access data and information wirelessly. These heterogeneous wireless technologies are similar in that they both allow users to access data on their PCs or PDAs without using network or modem cables. These technologies are also rather different in their uses and applications. Therefore, a QoS mechanism is needed to address in such heterogeneous wireless network environment to satisfy users’ requirements. An OSGi (Open Services Gateway Initiative) home gateway system manages the integration of heterogeneous home networks protocols and devices to develop ubiquitous applications. Wired and wireless heterogeneous home networks have different QoS concerns. For instance, jitter and latency are important concerns in web phones, while packet loss ratio is important in on-line video. This dissertation adopts UPnP QoS specification version 1.0 to design an adaptive QoS management mechanism based on the RMD (Resource Management in Diffserv) architecture. This dissertation monitors real-time network traffic, and adaptively controls the bandwidth, to satisfy the minimum requirement of each application in home network congestion. In the simulation results, we can find that after we build the QoS management mechanism into the RMD, total jitter, latency, and packet loss ratio has been decreased 0.1391 ms, 6.6 ms, and 5.43% respectively. To address different kinds of real-time applications, we decrease 4.53% packet loss ratio and increase 1.2% throughput for the high definition video streaming, decrease 1.89% packet loss ratio for standard definition video streaming, and for the VoIP (Voice over IP) we also decrease the jitter and latency to 0.0407 ms and 20.9 ms respectively. 2G/2.5G systems are designed to achieve 90-95% coverage. Most operators construct 3G base stations on previous 2G/2.5G stations. Consequently, integrated radio resource management is comprised of timeslot-limited and interference-limited systems. To improve capacity, this dissertation presents a novel resource management based on timeslot utilization in an integrated GPRS/UMTS service network. Although this approach gives UMTS high priority for sending data services, it also makes voice services available over GSM. In the simulation results, each data session of 64 kbps increases 7.14% in the capacity of the integrated system. Each data session of 128 kbps increases 13.33% in the capacity of the integrated system. WLAN services are inexpensive and have a high bandwidth, while UMTS services provide wider coverage area and higher mobility. Based on intelligent deduction, this dissertation presents a novel service scheduling scheme for WLAN/UMTS dual-mode networks. The proposed system, Distributed Multi-Agent System (DMAS), consists of a set of problem-solving agents that autonomously process their own tasks and interoperate with one another by a shared database to reach a suitable schedule for dual-mode network services. A two-level control mechanism comprising local-control and meta-control is presented to achieve a high degree of goodness in service scheduling. In the simulation result, the delay of integrated WLAN/UMTS system is between 80.9ms in UMTS and 12.4ms in WLAN. The jitter of integrated WLAN/UMTS system is greater than the jitter in pure WLAN (0.00061) and pure UMTS (0.0049). However, the effect in jitter happen only when mobile users handoff frequently between two different networks. Although the analyses of delay and jitter in integrated WLAN/UMTS network are not all better than in pure WLAN and in pure UMTS, integrated WLAN/UMTS system combines simultaneously the advantages of UMTS and WLAN. Keywords: QoS, Heterogeneous Wireless Network, OSGi, Resource Management, Distributed Multi-Agent System