Evaluating location management schemes for third generation mobile networks

Several strategies have been proposed recently to improve the performance of the IS-41 location management scheme. A forwarding pointers' strategy and a built-in memory strategy are proposed to reduce the signaling cost for location update and improve the IS-41 location update procedure. In this paper, we present a performance analysis of each strategy in an arbitrary time interval. In this analysis, users are classified by their call to mobility ratio which is defined as the call arrival rate divided by the mobility rate. We evaluate each of these strategies using this call to mobility ratio in order to come up with a set of recommendations that determine when each strategy is beneficial and for which class of users. We provide also a simplified analysis of the database loads generated by each strategy.     

Efficient location area planning for cellular networks with hierarchical location databases

Location area planning (LAP) is an important issue in the design of high-performance PCS networks. It could have a serious impact on the total mobility management cost of mobile terminals. Most of the previous works either explored the LAP problem as a 0–1 linear programming problem or used adopted techniques, such as simulated annealing, taboo search, and genetic algorithms [IEEE Trans. Vehicular Technol. 49 (2000) 1678; Proceedings of 1999 Vehicular Technology Conference, vol. 4, 1999, pp. 2119–2123; IEEE Vehicular Technol. Conf. 3 (1996) 1835; Proceedings of IEEE INFOCOM'01, Anchorage, Alaska, April 2001; IEEE Trans. Vehicular Technol. 47 (1998) 987], to derive a solution to minimize the location update cost. In this paper, we model and resolve the LAP problem as a set-covering problem. The main advantage of this approach is that it can adapt to the changing mobility patterns of the mobile terminals. We propose the set-covering-based location area planning (SCBLP) algorithm to minimize the total number of location updates, in which the cost-benefit functions are defined based on the coupling and cohesive functions among neighboring cells. We then apply SCBLP to the location database system with a hierarchical structure to further improve the overall system performance in searching and updating the location databases. Extensive simulation experiments have been conducted, and the experimental results show that our proposed algorithms can significantly reduce the location management costs, compared to the greedy algorithm and the random algorithm.     

An efficient location-based compromise-tolerant key management scheme for sensor networks

Location information has been paid much more attention in sensor network key management schemes. In 2006, Zhang et al. proposed a location-based key management scheme by binding private keys of individual nodes to both their identities and locations. In this Letter, however, we show that their scheme cannot resist key compromise impersonation (KCI) attack, and does not achieve forward secrecy. In fact, an adversary who compromises the location-based secret key of a sensor node A, can masquerade as any other legitimate node or even fake a node to establish the shared key with A, as well as decrypt all previous messages exchanged between A and its neighboring nodes. We then propose a new scheme which provides KCI resilience, perfect forward secrecy and is also immune to various known types of attacks. Moreover, our scheme does not require any pairing operation or map-to-point hash operation, which is more efficient and more suitable for low-power sensor nodes.     

Adaptive location updates for mobile sinks in wireless sensor networks

Mobile sinks can be used to balance energy consumption for sensor nodes in Wireless Sensor Networks (WSNs). Mobile sinks are required to inform sensor nodes about their new location information whenever necessary. However, frequent location updates from mobile sinks can lead to both rapid energy consumption of sensor nodes and increased collisions in wireless transmissions. We propose a new solution with adaptive location updates for mobile sinks to resolve this problem. When a sink moves, it only needs to broadcast its location information within a local area other than among the entire network. Both theoretical analysis and simulation studies show that this solution consumes less energy in each sensor node and also decreases collisions in wireless transmissions, which can be used in large-scale WSNs.

Protocols for mobility management in heterogeneous multi-hop wireless networks

Substantial works have recently been reported on the mobility management in single-hop wireless networks (e.g. cellular networks and WLAN hotspots), while there has been an increased interest in multi-hop communications. This has made mobility management in heterogeneous multi-hop wireless networks (HMWNs) really interesting so that both single-hop and multi-hop communication paradigms can be integrated. One of the main research challenges for 4G wireless systems is the identification of a mobility management technique that could integrate different wireless technologies such as WLANs, WMANs and WWANs, operating in infrastructure (single-hop) and infrastructureless (ad hoc or multi-hop) modes. In this article we envision a futuristic HMWN where heterogeneous networks, operating in single-hop and multi-hop modes are integrated to provide increased capacity and enhanced coverage for the users. We summarize various existing mobility management solutions and discuss why these schemes are not adequate for HMWNs, as well as highlighting our view of mobility management issues in HMWNs.     

Ad Hoc网络锚位置管理策略

在移动Ad hoc网络中,由于网络的自组织性、节点的频繁移动以及节点数目的增加,网络的开销迅速增大,这就直接影响到网络的可扩展性。目前,在移动Ad Hoc网络中越来越多地引入了位置管理的策略,以达到减少网络开销的目的。引入锚策略的思想,提出了一种新的位置管理策略。在这种锚策略下,离家乡区域较远节点的位置更新不需报告它的家乡区域,该节点只需把位置更新信息登记到附近的锚区域。通过与其他策略的仿真比较,证明其在性能上具有更好的可扩展性。     

一种分层的无线传感器网络密钥管理方案*

针对现有密钥管理方案抗俘获性差和占据存储空间大等缺点,提出了一种分层的密钥管理方案。簇头节点采用了Blom矩阵,有效提高了簇头节点抗击俘获的能力;簇内节点利用中国剩余定理,在将复杂计算转交给基站的同时,降低了组密钥的存储空间。通过对比分析,该方案较好地满足了WSNs密钥管理的相关指标,提高了安全性能。     

无线传感器网络中基于ID密钥管理方案

为了减少在密钥生成时的数据通信,在分析Park密钥预分配方案的基础上,提出一个基于传感器ID的密钥管理方案.该方案不仅明显降低了生成密钥时的通信开销,而且确保所有的节点均能建立安全链路.分析表明,该方案还具有较强的抵抗攻击能力.     

基于group-based模型的无线传感器网络密钥管理方案

由于无线传感器网络受电源、计算能力、内存容量等方面的限制,传统的基于公钥和可信任的密钥管理方式不再适用.为了进一步提高无线传感器网络的安全连通性,在分析DU Wen-liang等人的group-based节点投放模型的基础上,提出了一种改进的密钥管理方案:多密钥空间与多路径增强相结合的随机密钥预分配方案.结果分析表明,该方案需要较少的内存存储空间,不仅提高了系统的连通性,还降低了节点的被捕获概率.     

A scalable key management and clustering scheme for wireless ad hoc and sensor networks

This paper describes a scalable key management and clustering scheme for secure group communications in ad hoc and sensor networks. The scalability problem is solved by partitioning the communicating devices into subgroups, with a leader in each subgroup, and further organizing the subgroups into hierarchies. Each level of the hierarchy is called a tier or layer. Key generation, distribution, and actual data transmissions follow the hierarchy. The distributed, efficient clustering approach (DECA) provides robust clustering to form subgroups, and analytical and simulation results demonstrate that DECA is energy-efficient and resilient against node mobility. Comparing with most other schemes, our approach is extremely scalable and efficient, provides more security guarantees, and is selective, adaptive and robust.     

An integrated protocol stack for efficient resources management in wireless networks

The area of ATM multihop radio networks has recently become an issue of interest especially with the growing interest in portable multimedia units. Multimedia communication requires a deterministic delivery of isochronous traffic with predefined QoS requirements. In this paper we propose an integrated protocol stack which provides deterministic delivery bounds and efficiently utilizes channel backwidth. By integrating the access, routing and congestion control protocols, a solution is provided which improves bandwidth utilization, maintains shortest route packet delivery and leads to congestion avoidance. A tractable approximate analytical model is developed and verified for networks with finite storage capacity. For large multihop networks the analytical solution is complemented by simulation. Evaluation shows that the proposed protocol integration yields a significant reduction in end-to-end delay, which together with bounded access time at the channel access level, provide two essential features for the support of isochronous traffic in multihop wireless environments.     

基于group based模型的无线传感器网络密钥管理方案*

由于无线传感器网络受电源、计算能力、内存容量等方面的限制,传统的基于公钥和可信任的密钥管理方式不再适用。为了进一步提高无线传感器网络的安全连通性,在分析DU Wenliang等人的groupbased节点投放模型的基础上,提出了一种改进的密钥管理方案：多密钥空间与多路径增强相结合的随机密钥预分配方案。结果分析表明,该方案需要较少的内存存储空间,不仅提高了系统的连通性,还降低了节点的被捕获概率。     

Distributed cell-centric neighborhood-related location area planning for PCS networks

An intelligent location area planning (LAP) scheme should consider the frequent replannings of location areas (LAs) due to changes in user distribution and mobility patterns along with optimization of location management costs, including location updating and paging costs. Most schemes proposed in the literature are designed through centralized techniques, thus requiring more computing time to plan the LAs. Frequent replannings to accommodate environmental changes make the situation worse. As to the optimization of location management costs, most proposed schemes consider the inter-cell crossing rate as one of the key factors in determining the optimal partitions. In some cases, the inter-cell crossing rate may lead to an unsatisfactory outcome. Another problem is the ping-pong effect which is caused by the fixed borders between any two of LAs. In this paper, we propose a distributed cell-centric neighborhood-related LAP scheme in which each cell acts as the center of an LA and in which highly correlative neighboring cells are bundled into the LA if mobile terminals (MTs) remain within the LA long enough to reduce costs. Moreover, the ping-pong effect will be alleviated because MTs always locate at the center cell of an LA whenever a new location update is performed. Finally, the scheme can be implemented in a distributed manner so the computing time incurred by frequent replannings can be reduced. Simulation results show that our scheme indeed exhibits excellent results.     

基于多项式和混沌序列的无线传感器网络密钥管理方案*

针对现有密钥管理方案占据存储空间大和安全性差的缺点,提出了一种基于多项式和混沌序列的混合密钥管理方案。该方案使用多项式建立节点间的共享密钥减少网络的存储开销,利用混沌序列对初值的敏感性特点解决多项式安全门限的问题,从而防止密钥的泄露。结果表明,本方案具有很高的安全性能,不仅节约了网络的通信资源,而且降低了节点的存储开销。     

基于身份密码学的异构传感网络密钥管理方案

在充分考虑异构无线传感器网络自身特点的基础上,针对现有无线传感器网络密钥管理中存在的问题,利用基于身份的加密算法(Identity-Based Cryptography,IBC),提出了一种异构无线传感器网络密钥管理方案(KMUIBC),并从该方案的安全性、连通性、可扩展性、有效性等方面进行分析,与现有的一些典型方案进行了分析比较,结果表明,KMUIBC有较好的性能。     

无线传感器网络密钥管理方案前向安全性研究

对现有的基于椭圆曲线的无线传感器网络密钥管理方案进行了分析研究,针对现有密钥管理算法不具备前向安全性的问题,以相对简单及较为经典的两个方案为基础,将前向安全的概念引入到密钥管理方案之中,实现了前向安全在椭圆曲线无线传感器网络密钥管理方案中的应用。在此基础上,应用硬件节点MICAz进行硬件模拟,分析了方案的安全性、存储消耗、运行时间,验证了方案的适用性。     

机会网络中基于能量消耗的缓存管理策略

为了减少机会网络中节点的能量消耗,均衡各节点之间能量使用情况,延长网络寿命,提出基于能耗的缓存管理策略。在节点缓存空间有限的情况下,所提出的算法根据周围邻居节点能量的使用情况,动态调整节点用于缓存转发消息空间的大小,从而减少节点在存储-转发过程中的能量消耗。同时,为了避免传统休眠机制的能耗路由算法中由于目的节点休眠而导致消息投递失败的情况,引入了新的Inactive节点状态。实验仿真表明,与定时休眠机制的能耗算法比较,采用基于能量消耗的缓存管理策略能够使得机会网络中所有节点的整体能耗降低50%左右,并且节点之间能耗的标准差降低80%以上。     

分布式网络环境下基于区块链的密钥管理方案

为解决在分布式网络实施密钥管理困难和通信开销过大等问题,提出一种基于区块链技术的密钥管理方案（KMSBoB,key management schemes based on Blockchain）。KMSBoB中设计了分布式群组网络下基于区块链的密钥管理和传输过程,并将区块链全体成员挖矿过程和MTI/CO协议过程相结合形成动态生成会话密钥生成协议,简化了跨异构自治域下的密钥管理策略。通过仿真测试和结果分析表明 KMSBoB 的安全性和有效性,并且相比传统密钥管理方案通信开销更少和扩展性更高。     

A location-based mobility tracking scheme for PCS networks

This paper introduces a location-based locating strategy for Personal Communication Services (PCS) systems. In the proposed scheme, location updates are based on the value of a movement counter. The update of the movement counter is based on information on the locations visited by a mobile terminal (MT) since the last location update. In particular, the cell identifiers and the corresponding movement counter values are maintained in the MT for a part of the visited cells since the last location update. When the MT enters a cell whose identifier is not stored in the MT, the movement counter increases by one. If the movement counter reaches the update threshold, a location update is triggered; otherwise, the cell identifier and the corresponding movement counter value are stored in the MT. When the MT enters a cell whose identifier is in the MT, the movement counter is assigned with the counter value kept in the MT for this cell, and all cells with greater counter values in the MT are removed. The proposed scheme allows the dynamic selection of the update threshold according to each user's calling and mobility patterns. Analytical and simulation models have been developed to compare the proposed scheme with both the movement-based scheme and the distance-based scheme. Results demonstrate that when the call-to-mobility ratio (CMR) is low, the proposed scheme can achieve a significant cost reduction compared to the movement-based scheme. For example, when the CMR is 0.01, a savings of around 25% in the optimal total cost per call arrival is achieved with the proposed scheme. Moreover, the proposed scheme is easier to implement than the distance-based scheme.     

基于环-树型拓扑的无线传感网密钥管理方案

设计了一种基于无线传感网的拓扑模型--环-树型网络拓扑模型.基于该模型,结合节点命名机制,提出了一种新的密钥管理方案.该方案在拓扑结构上改变传统的三层分簇拓扑为四层分簇拓扑,在路由安全问题上采用二次核实机制.经仿真工具OMNET++实验,较传统的三层分簇拓扑模型,该方案的网络拓扑模型延长了第一个节点的死亡时间,且整个网络具有更长的生命周期和更好的安全保证.