A Quorum-Based Management Scheme for Ad-Hoc Networking

随着网络规模和配置变化速度的不断增加，自组织网络中的移动性管理有望成为此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的节点可能频繁不可达(由于这种网络中的间歇性无线连接)，以及移动与特定HLR的关联需要将该信息传播到网络中可能频繁改变的所有网络节点。在提出的方案中，网络中的一个节点子集动态地承担“移动报告中心”(MRCS)的功能。移动设备的“位置”被报告给一组(法定数)的MRC。为了定位移动设备，查询可能不同于所报告的集合的集合(法定数)。当任意两个Quorum相交时，保证查询操作产生手机的位置。由于在多个MRC中法定人数可能重叠，因此与有限数量的MRC的连接丢失可能不会影响该方案定位移动站的能力。最后，由于Quorum创建的“全网已知”方案，不需要传播移动设备与特定MRC的关联信息--来自两个Quorum的任何报告和查询都将产生所寻求的答案。在拟议的为期一年的可行性研究中，我们将处理以下主题：(I)基于法定人数的移动性管理方案的复杂性和相关开销的研究；(Ii)在有限的网络负载和统一的MRC处理负载的情况下确保高可靠性的法定构建策略；(Iii)减少在重新配置期间发生错误操作和/或查询结果不一致的可能性；

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;