Gotowa bibliografia na temat „3G Cellular, WLAN, Interworking, Mobility Management”

Purpose – The paper aims to propose an optimized handover necessity estimation scheme for a mobile terminal (MT) traversing from a third-generation (3G) cellular network into the wireless local area network (WLAN) cell for reducing the number of handover failures and unnecessary handovers. Design/methodology/approach – The proposed optimized handover necessity estimation scheme comprises of two algorithms – a “travelling time prediction” reliant on consecutive received signal strength (RSS) measurements and MT’s velocity, and a “time threshold estimation” depending on the handover latency, WLAN’s cell radius, tolerable handover failure probability and the tolerable unnecessary handover probability. Findings – Our performance analysis reveals that the suggested mechanism effectively minimizes the number of handover failures and unnecessary handovers by 60 per cent as compared to the already proposed schemes in the literature. Originality/value – The convergence of Internet and wireless mobile communication accompanied by a massive increase in the number of cellular subscribers has led mobility management to emerge as a significant and challenging domain for wireless mobile communication over the Internet. Mobility management enables serving networks to locate roaming terminals for the call delivery (location management) and ensures a seamless connection as MT enters into the new service area (handover management). In this manuscript, an optimized handover necessity estimation scheme has been envisaged for reducing the probability of handover failures and unnecessary handovers from 3G cellular networks to WLANs to provide optimal network utilization along with an enhanced user satisfaction. Performance analysis reveals that the suggested scheme yields enhanced results as compared to the schemes already proposed in the literature.

Doctor of Philosophy (Ph.D.)
The buzzword of this decade has been convergence: the convergence of telecommunications, Internet, entertainment, and information technologies for the seamless provisioning of multimedia services across different network types. Thus the future Next Generation Mobile Network (NGMN) can be envisioned as a group of co-existing heterogeneous mobile data networking technologies sharing a common Internet Protocol (IP) based backbone. In such all-IP based heterogeneous networking environments, ongoing sessions from roaming users are subjected to frequent vertical handoffs across network boundaries. Therefore, ensuring uninterrupted service continuity during session handoffs requires successful mobility and session management mechanisms to be implemented in these participating access networks. Therefore, it is essential for a common interworking framework to be in place for ensuring seamless service continuity over dissimilar networks to enable a potential user to freely roam from one network to another. For the best of our knowledge, the need for a suitable unified mobility and session management framework for the NGMN has not been successfully addressed as yet. This can be seen as the primary motivation of this research. Therefore, the key objectives of this thesis can be stated as:  To propose a mobility-aware novel architecture for interworking between heterogeneous mobile data networks  To propose a framework for facilitating unified real-time session management (inclusive of session establishment and seamless session handoff) across these different networks. In order to achieve the above goals, an interworking architecture is designed by incorporating the IP Multimedia Subsystem (IMS) as the coupling mediator between dissipate mobile data networking technologies. Subsequently, two different mobility management frameworks are proposed and implemented over the initial interworking architectural design. The first mobility management framework is fully handled by the IMS at the Application Layer. This framework is primarily dependant on the IMS’s default session management protocol, which is the Session Initiation Protocol (SIP). The second framework is a combined method based on SIP and the Mobile IP (MIP) protocols, which is essentially operated at the Network Layer. An analytical model is derived for evaluating the proposed scheme for analyzing the network Quality of Service (QoS) metrics and measures involved in session mobility management for the proposed mobility management frameworks. More precisely, these analyzed QoS metrics include vertical handoff delay, transient packet loss, jitter, and signaling overhead/cost. The results of the QoS analysis indicates that a MIP-SIP based mobility management framework performs better than its predecessor, the Pure-SIP based mobility management method. Also, the analysis results indicate that the QoS performances for the investigated parameters are within acceptable levels for real-time VoIP conversations. An OPNET based simulation platform is also used for modeling the proposed mobility management frameworks. All simulated scenarios prove to be capable of performing successful VoIP session handoffs between dissimilar networks whilst maintaining acceptable QoS levels. Lastly, based on the findings, the contributions made by this thesis can be summarized as:  The development of a novel framework for interworked heterogeneous mobile data networks in a NGMN environment.  The final design conveniently enables 3G cellular technologies (such as the Universal Mobile Telecommunications Systems (UMTS) or Code Division Multiple Access 2000 (CDMA2000) type systems), Wireless Local Area Networking (WLAN) technologies, and Wireless Metropolitan Area Networking (WMAN) technologies (e.g., Broadband Wireless Access (BWA) systems such as WiMAX) to interwork under a common signaling platform.  The introduction of a novel unified/centralized mobility and session management platform by exploiting the IMS as a universal coupling mediator for real-time session negotiation and management.  This enables a roaming user to seamlessly handoff sessions between different heterogeneous networks.  As secondary outcomes of this thesis, an analytical framework and an OPNET simulation framework are developed for analyzing vertical handoff performance. This OPNET simulation platform is suitable for commercial use.

The buzzword of this decade has been convergence: the convergence of telecommunications, Internet, entertainment, and information technologies for the seamless provisioning of multimedia services across different network types. Thus the future Next Generation Mobile Network (NGMN) can be envisioned as a group of co-existing heterogeneous mobile data networking technologies sharing a common Internet Protocol (IP) based backbone. In such all-IP based heterogeneous networking environments, ongoing sessions from roaming users are subjected to frequent vertical handoffs across network boundaries. Therefore, ensuring uninterrupted service continuity during session handoffs requires successful mobility and session management mechanisms to be implemented in these participating access networks. Therefore, it is essential for a common interworking framework to be in place for ensuring seamless service continuity over dissimilar networks to enable a potential user to freely roam from one network to another. For the best of our knowledge, the need for a suitable unified mobility and session management framework for the NGMN has not been successfully addressed as yet. This can be seen as the primary motivation of this research. Therefore, the key objectives of this thesis can be stated as:  To propose a mobility-aware novel architecture for interworking between heterogeneous mobile data networks  To propose a framework for facilitating unified real-time session management (inclusive of session establishment and seamless session handoff) across these different networks. In order to achieve the above goals, an interworking architecture is designed by incorporating the IP Multimedia Subsystem (IMS) as the coupling mediator between dissipate mobile data networking technologies. Subsequently, two different mobility management frameworks are proposed and implemented over the initial interworking architectural design. The first mobility management framework is fully handled by the IMS at the Application Layer. This framework is primarily dependant on the IMS’s default session management protocol, which is the Session Initiation Protocol (SIP). The second framework is a combined method based on SIP and the Mobile IP (MIP) protocols, which is essentially operated at the Network Layer. An analytical model is derived for evaluating the proposed scheme for analyzing the network Quality of Service (QoS) metrics and measures involved in session mobility management for the proposed mobility management frameworks. More precisely, these analyzed QoS metrics include vertical handoff delay, transient packet loss, jitter, and signaling overhead/cost. The results of the QoS analysis indicates that a MIP-SIP based mobility management framework performs better than its predecessor, the Pure-SIP based mobility management method. Also, the analysis results indicate that the QoS performances for the investigated parameters are within acceptable levels for real-time VoIP conversations. An OPNET based simulation platform is also used for modeling the proposed mobility management frameworks. All simulated scenarios prove to be capable of performing successful VoIP session handoffs between dissimilar networks whilst maintaining acceptable QoS levels. Lastly, based on the findings, the contributions made by this thesis can be summarized as:  The development of a novel framework for interworked heterogeneous mobile data networks in a NGMN environment.  The final design conveniently enables 3G cellular technologies (such as the Universal Mobile Telecommunications Systems (UMTS) or Code Division Multiple Access 2000 (CDMA2000) type systems), Wireless Local Area Networking (WLAN) technologies, and Wireless Metropolitan Area Networking (WMAN) technologies (e.g., Broadband Wireless Access (BWA) systems such as WiMAX) to interwork under a common signaling platform.  The introduction of a novel unified/centralized mobility and session management platform by exploiting the IMS as a universal coupling mediator for real-time session negotiation and management.  This enables a roaming user to seamlessly handoff sessions between different heterogeneous networks.  As secondary outcomes of this thesis, an analytical framework and an OPNET simulation framework are developed for analyzing vertical handoff performance. This OPNET simulation platform is suitable for commercial use.

碩士
朝陽科技大學
網路與通訊研究所
93
The mobile communication technology becomes more and more popular in the recently years. The 3G (Third generation) mobile communication system has large coverage, high speed mobility, completed subscriber management (billing system) and nearly universal roaming. On the other hand, the wireless local area network (WLAN) provides a solution for the internet access which has small coverage, low speed mobility and high data transmission rates. Some researches point out that integrates those two wireless technologies will get advantage since their characteristics are complementary under some conditions. 3GPP proposed some specifications of 3G/UMTS-WLAN interworking which give an approach for a flexible, scalable, and general way of the 3G/UMTS-WLAN interworking. However, the research of 3G/UMTS-WLAN interworking specifications still in process of more requirement such as service continuity, seamless handoff, efficient mobility management (MM) and so on. Meanwhile, the original MM method in IP (Internet Protocol) protocol will become more important since the IP-based core network is required in the next-generation (NG) heterogeneous wireless network system. As the above reasons, this study focus on the 3G/UMTS-WLAN interworking architecture and use it as the start of the NG all-IP-based heterogeneous networks. In this study, we will review the Mobile IP protocol, present MM scheme and the other important issues such as registration procedure, security, network architecture design…etc. Furthermore, we will propose a mobility management architecture including localized fast re-authentication and handoff procedure for the 3G/UMTS-WLAN interworking. Our proposed architecture uses pre-register conception joins forces with localized fast re-authentication. Therefore, our proposed architecture improves the efficiency of 3G/UMTS-WLAN interworking mobility management and solves some problems under particular conditions.

Recent development on the wireless networks has indicated that IEEE 802.11.x standards based wireless LAN and third-generation cellular wireless networks such as CDMA2000 or UMTS (i.e., WCDMA) could be integrated together to offer ubiquitous Internet access to end users. The two technologies can offer functions that are complementary to each other. The 802.11. x standards based wireless LANs support data rates from 1 Mbps to 54 Mbps. However, by IEEE 802.11.x standard, one access point (AP) can only cover an area of a few thousand square meters. It is perfectly applied for enterprise networks and public hot-spots such as hotels and airports. On the contrary, wireless cellular networks built with 3G standards can only support peak data transmission rates from 64Kbps to nearly 2 Mbps with a much wider area. It is reasonable and feasible to combine these two technologies to make Internet access much easier and more convenient. The design of an interworking architecture to efficiently integrate 3G cellular wireless networks and 802.11.x standard based wireless LANs is a challenge. Its difficulty lies in the objective of the integration, which is to achieve the seamless interoperation between the two types of the wireless networks with certain QoS guarantee and other requirements kept simultaneously, from the perspectives of both the end-users and the operators. There are basically two proposals as the solutions to the architecture of the integration. One is the tight coupling. The other is the loose coupling. Although there is no final selection on whether the future integrated network would use either of these techniques or another one, much focus of the research is on the loose coupling due to its feasibility. To implement the integration based on the corresponding approach, there are a lot of issues needed to be addressed. They are the mobility management for vertical handoff, the QoS maintenance during the vertical handoff, and the schemes of authentication, authorization and the accounting (AAA). In this article, we will focus on the issue of interworking architecture. The rest of the text is organized as follows. The second section will present the general ideas on the architecture of the integration of 3G cellular networks with wireless LANs. The third section will present several proposals on the architectures of the integration. At last, the fourth section will conclude the article.