Addressing, Routing, and Information Provisioning Mechanisms for Hierarchical Mobile Networks
| Autor: | Yuan-Ying Hsu, 徐元瑛 |
|---|---|
| Rok vydání: | 2005 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 93 With the advance of wireless and terminal technologies, various wireless networks, such as mobile ad-hoc networks, wireless sensor networks, wireless mesh networks, and mobile networks, are designed for different purposes. A wireless network may move as a whole and furthermore may overlay with one another to form a hierarchical mobile network. Hierarchical mobile netoworks provide a flexible approach for mobile nodes to access Infrastruture networks with any appropriate wireless technologies. However, many technical issues need to be resolved for mobile nodes to roam within a hierarchical mobile network environment. In this thesis, we propose several mechanisms for network addressing, routing and information provisioning in hierarchical mobile networks. Current address allocations usually involve broadcasting, which introduces huge overhead in multi-hop environments, for address solicitation or duplicate address detection. We propose a Prime DHCP scheme that can allocate addresses to hosts without broadcasting over the whole network. Prime DHCP makes each host a DHCP proxy and run a prime numbering address allocation algorithm individually to compute unique addresses. The concept of DHCP proxies and the prime numbering address allocation algorithm together eliminate the needs for broadcasting. Based on the address allocation result by Prime DHCP, we propose a prime-based self-configured routing protocol for each node to route data packets to other local nodes within the same network. With the proposed routing protocol, each node can derive a routing path to a local node according to the node’s address without periodically exchanging routing information with other nodes. Furthermore, the node need not send a routing request to the destined node before forwarding packets to the local node, either. For packets destined to external networks, we configure at least one gateway in each wireless network, and have the gateways responsible for routing packets from/to external networks. To support host mobility, we adopt mobile IP with minor modifications, and we also propose a load-balanced routing protocol to balance external traffic between multiple gateways. Besides network addressing and routing mechanisms, we also propose information provisioning mechanisms for hierarchical mobile networks. When a gateway needs to serve a lot of mobile nodes, the external bandwidth would be shared by all the mobile nodes beneath the gateway. We propose a two-tier proxy architecture and a load-based scheduling mechanism to schedule traffic according to data sizes. Furthermore, personal information of a user might be stored in various devices. Therefore we also propose a personal information hierarchy (PIH) to store personal information and corresponding information accessing policies for PIH by adapting the successful experience of memory hierarchy. We have conducted performance evaluation for all proposed mechanisms. Performance results show that prime DHCP can significantly reduce the signal overhead and the latency for hosts to acquire addresses; prime-based self-configured routing protocol can significantly decrease path setup time and signal overhead; and the PIH architecture and accessing policies together can significantly increase the storage capacity with a negligible decrease in access speed a user can experience in personal information management. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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