A Quorum-Based Management Scheme for Ad-Hoc Networking

随着规模的增加和配置变化的速率，ad-hoc网络中的移动性管理预计将成为这类网络设计中的基本挑战之一。传统的基于HLR/VLR的移动性管理方案的基本缺点源于两个问题：用作HLR的节点可能经常不可达（由于这种网络中的间歇性无线连接），以及移动的与特定HLR的关联需要将该信息传播到所有网络节点，网络中的这些网络节点的存在可能经常改变。 在所提出的方案中，在网络中的节点的子集动态地承担“移动性报告中心”（MRC）的功能。将移动的的“位置”报告给一组（法定）MRC。为了定位移动的，查询可能与被分配到的集合不同的集合（quorum）。当任何两个法定人数相交时，确保查询操作产生移动的的位置。由于法定人数可能在多个MRC中重叠，因此与有限数量的MRC的连接性的丢失可能对该方案定位移动的的能力没有影响。最后，由于用于法定人数创建的“全网络已知”方案，不需要传播移动的与特定MRC的关联的信息--任何向两个法定人数的查询和从两个法定人数的查询将产生所寻求的答案。 在建议的一年可行性研究中，我们会处理以下课题：（i）研究以法定人数为基础的流动性管理方案的复杂性及相关的开销;（ii）法定人数构建策略，以确保在有限的网络负荷及统一的MRC处理负荷下的高度可靠性;（iii）减少在重新配置期间发生错误操作及/或不一致查询结果的概率;

With increasing size and the rate at which their configuration change, mobility management in ad-hoc networks is expected to be one of the basic challenges in the design of this breed of networks. The basic shortcoming of the traditional HLR/VLR based mobility management schemes stems from two problems: nodes that serve as HLRs may be frequently unreachable (due to the intermittent wireless connectivity in such networks) and the association of a mobile with a particular HLR requires dissemination of this information to all the network nodes, presence of which in the network may frequently change. In the proposed scheme, a subset of nodes in the network dynamically assumes the function of the "Mobility Reporting Centers" (MRCs). The "location" of a mobile is reported to a set (quorum) of the MRCs. To locate a mobile, a set (quorum), possibly different from the reported-to one, is queried. As any two quorums intersect, the querying operation is ensured to produce the location of the mobile. As the quorums may overlap in multiple MRCs, loss of connectivity with a limited number of MRCs may have no effect on the ability of the scheme to locate a mobile. Finally, due to the "network-wide known" scheme for quorum creation, there is no need to disseminate the information of association of a mobile with a particular MRC - any reported-to and queried-from two quorums will produce the sought answer. In the proposed one-year feasibility study, we will tackle the following topics: (i) study of the complexity and associated overhead of the quorum-based mobility management scheme' (ii) quorum construction strategies that ensure high degree of reliability with limited network load and uniform MRCs' processing load; (iii) reduction of the probability of erroneous operations and/or inconsistent querying results during the reconfiguration periods;