在傳統的有線網路中，每一個設備要連線到網際網路中必須設定相關的IP位址資訊才可以跟其它設備連通，這些IP位址的自動設定方法一般是採用一個集中式的DHCP伺服器來統一分配IP位址相關資訊給參與網路的設備，但是這樣的方式並不適合用在MANETs的環境裡。由於各設備會動態的移動或是離開網路，所以DHCP伺服器並沒有辦法保證在MANETs的環境下，可以讓每一個設備都可以連線到自己。在這篇論文裡，我們提出一個利用位置資訊來為新參與的網路設備設定IP位址的方法，我們事先將整個網路區域分割成數個大小相同的蜂巢狀小區域，每個小區域會被分配到一段彼此沒有交集的IP位址區段。在一個蜂巢狀小區域中第一個出現的網路設備會成為coordinator的角色，接著出現的網路設備則會成為member的角色，coordinator負責分配IP位址給後來加入此蜂巢狀小區域的網路設備，和維護此蜂巢狀小區域中所有的可用IP位址，member則可以透過coordinator來取得一個唯一的IP位址。在MANETs環境中，網路設備有可能呈現不平均的分佈情形，造成部分的coordinators沒有足夠的IP位址可以分配給新加入的網路設備，因此我們提出了一個可用IP位址重新分配的機制，當IP位址不足夠時，可以做動態的調整以增加可用IP位址的個數。藉由位置資訊的輔助，這篇論文所提出的方法可以完全避免掉網路合併和分解的問題，可用IP位址可以有效率的被使用，且要求一個新IP位址時所花費的延遲時間是可被接受的。 In traditional wired networks, hosts are assigned IP-related information by a centralized server like Dynamic Host Configuration Protocol (DHCP) server, but it is not suitable for Mobile Ad Hoc Networks (MANETs). Due to each host will move and leave the network dynamically, the DHCP server cannot guarantee to be accessed by each host in the MANETs. Several decentralized solutions have been proposed for the issue of IP assignment. A new IP-address allocation algorithm, namely location-based IP assignment protocol, is proposed in this thesis. We divide the entire network into several disjoint and the same size cells and allocate each cell a segment of available IP-addresses. The first host appears in each cell becomes the role of coordinator which take over the available IP-addresses of the cell. A coordinator is responsible for assigning an IP-address to the new host and maintaining the IP-address pool of its own cell. Therefore, when a non-coordinator host enters any cell, it can easily get one IP-address from the coordinator. Since the distribution of the hosts is not uniform in the network, some coordinators may not have enough available IP-addresses for the new hosts. Thus, a dynamic IP-address redistribution mechanism is proposed to adjust the number of IP-addresses in each cell. With location information of each host, the scheme proposed in this thesis can avoid the problems of network partitioning and merger. The IP-addresses can be fully utilized and the latency time on invoking an IP-address is acceptable.
