A secure fast handover scheme based on AAA protocol in mobile IPv6 networks

In order to reduce the cost and decrease the delay caused by combining the AAA function while guaranteeing the fast handover performance, we bring out an enhanced secure fast handover scheme. Our research focuses on improving the security and reducing the delay during the handover process of mobile IPv6, the most important thing is to minimize the authentication latency in AAA processing. According to the scheme referred above, the performance evaluation is analyzed in terms of pedestrian and vehicle, and the results of simulation show that the proposed mechanism reduces the handoff and authentication latency evidently compared to the previous simple traditional combination modeling.     

Energy-efficient neighbor discovery protocol for mobile wireless sensor networks

Low energy consumption is a critical design requirement for most wireless sensor network (WSN) applications. Due to minimal transmission power levels, time-varying environmental factors and mobility of nodes, network neighborhood changes frequently. In these conditions, the most critical issue for energy is to minimize the transactions and time consumed for neighbor discovery operations. In this paper, we present an energy-efficient neighbor discovery protocol targeted at synchronized low duty-cycle medium access control (MAC) schemes such as IEEE 802.15.4 and S-MAC. The protocol effectively reduces the need for costly network scans by proactively distributing node schedule information in MAC protocol beacons and by using this information for establishing new communication links. Energy consumption is further reduced by optimizing the beacon transmission rate. The protocol is validated by performance analysis and experimental measurements with physical WSN prototypes. Experimental results show that the protocol can reduce node energy consumption up to 80% at 1–3 m/s node mobility.     

Enhanced fast handover for proxy mobile IPv6 in vehicular networks

To reduce the handover latency in PMIPv6, Fast Handover for PMIPv6 (PFMIPv6) is being standardized in the IETF. On the other hand, vehicle-roadside data access has been envisioned to be useful in many commercial Internet services; however, integrating the current Internet into Vehicular Networks (VNs) presents a new set of challenges. In particular, to provide rapid IP handover in the VNs, simply applying PFMIPv6 to VNs may not improve handover performance since PFMIPv6 handover restricts the previous Mobile Access Gateway (MAG) from forwarding the packets until it receives an HAck/HI from the next MAG, even though the vehicle may have already arrived at the next MAG. We also note that PFMIPv6 does not consider the impact of geographic restriction on vehicular mobility. Therefore, in this paper, we propose an enhanced PFMIPv6 (ePFMIPv6) for VNs in which the serving MAG pre-establishes a tunnel with candidate next MAGs for next MAG so that the packets can be immediately forwarded to the next MAG once the serving MAG is indicated the vehicle’s handover by the serving road side unit. To evaluate the performance of the proposed protocol, we derive analytical expressions for packet loss, latency and signaling overhead caused by ePFMIPv6 and PFMIPv6 handovers. Our analytical study is verified by simulation results.     

A hybrid handover protocol for local area wireless ATM networks

While handovers of voice calls in a wide area mobile environment are well understood, handovers of multi-media traffic in a local area mobile environment is still in its early stage of investigation. Unlike the public wireless networks, handovers for multi-media Wireless LANs (WLANs) have special requirements. In this paper, the problems and challenges faced in a multi-media WLAN environment are outlined and a multi-tier wireless cell clustering architecture is introduced. Design issues for multi-media handovers are specified and a fast, continuous and efficient hybrid handover protocol is proposed. The protocol is scalable and supports source and destination mobile handovers in a mutually exclusive manner. Crossover switch (CX) discovery is also introduced to support fast inter-cluster handovers with consideration given to Mobile Quality of Service (M-QoS). The resulting wireless ATM LAN exhibits a distributed mobile location management, call admission control and handover management architecture. A prototype of the proposed handover protocol is implemented into a Cambridge Fairisle ATM switch and the results of handovers for a single Mobile Host (MH) with a single on-going connection are evaluated. It was found that implementing transport mobility for a wireless ATM environment is not practical as the cell re-routing function changes the traffic characteristics and is not scalable to increasing cell rate and to the number of mobile connections. The data-link layer mobility implementation however, is found to work well. The protocol provides symmetric data disruption to traffic flows in both directions and up to seventy-five intra-cluster handovers can be supported in a second. Throughout the experiment, cells arrive in sequence with no cell loss observed during the handover, up to the capacity limit of the ATM switch. Finally, zig-zag handovers and handovers for a single MH with multiple on-going unicast connections are performed in order to evaluate the robustness and performance of the protocol under different MHs' migration and communication environment.Parts of this paper appeared in the ACM First International Conference on Mobile Computing and Networking (MOBICOM'95), Berkeley, California, November 1995 as The Design & Implementation of A Hybrid Handover Protocol For Multi-Media Wireless LANs.C-K Toh is supported by a King's College Cambridge External Research Studentship and a Cambridge Commonwealth Trust Scholarship.     

A distributed data storage protocol for heterogeneous wireless sensor networks with mobile sinks

This paper presents ProFlex, a distributed data storage protocol for large-scale Heterogeneous Wireless Sensor Networks (HWSNs) with mobile sinks. ProFlex guarantees robustness in data collection by intelligently managing data replication among selected storage nodes in the network. Contrarily to related protocols in the literature, ProFlex considers the resource constraints of sensor nodes and constructs multiple data replication structures, which are managed by more powerful nodes. Additionally, ProFlex takes advantage of the higher communication range of such powerful nodes and uses the long-range links to improve data distribution by storage nodes. When compared with related protocols, we show through simulation that Proflex has an acceptable performance under message loss scenarios, decreases the overhead of transmitted messages, and decreases the occurrence of the energy hole problem. Moreover, we propose an improvement that allows the protocol to leverage the inherent data correlation and redundancy of wireless sensor networks in order to decrease even further the protocol’s overhead without affecting the quality of the data distribution by storage nodes.     

A schedule‐based medium access control protocol for mobile wireless sensor networks

Recent advances in body area network technologies such as radio frequency identification and ham radio, to name a few, have introduced a huge gap between the use of current wireless sensor network technologies and specific needs of some important wireless sensor network applications such as medical care, disaster relief, or emergency preparedness and response. In these types of applications, the mobility of nodes can occur, leading to the challenge of mobility handling. In this paper, we address this challenge by prioritizing transmissions of mobile nodes over static nodes. This is achieved by using shorter contention windows in reservation slots for mobile nodes (the so‐called backoff technique) combined with a novel hybrid medium access control (MAC) protocol (the so‐called versatile MAC). The proposed protocol advocates channel reuse for bandwidth efficiency and management purpose. Through extensive simulations, our protocol is compared with other MAC alternatives such as time division multiple access and IEEE 802.11 with request to send/clear to send exchange, chosen as benchmarks. The performance metrics used are bandwidth utilization, fairness of medium access, and energy consumption. The superiority of versatile MAC against the studied benchmark protocols is established with respect to these metrics. Copyright © 2012 John Wiley & Sons, Ltd.     

An efficient distributed routing protocol for wireless sensor networks with mobile sinks

Introducing mobile sinks into a wireless sensor network can effectively improve the network performance. However, sink mobility can bring excessive protocol overhead for route maintenance and may offset the benefit from using mobile sinks. In this paper, we propose a dynamic layered routing protocol to address this problem. The proposed protocol integrates dynamic layered Voronoi scoping and dynamic anchor selection to effectively reduce the dissemination scopes and frequencies of routing updates as the sinks move in the network. Simulation results show that the proposed protocol can effectively reduce the protocol overhead while ensuring high packet delivery ratio as compared with existing work. Copyright © 2014 John Wiley & Sons, Ltd.     

Sink-oriented tree based data dissemination protocol for mobile sinks wireless sensor networks

Wireless Networks - Data dissemination toward static sinks causes the nearby nodes to deplete their energy quicker than the other nodes in the field (i.e., this is referred to as the hotspot...     

无线传感器网络上轻量化的IPv6协议栈

传感器网络集成了传感器、微机电系统和网络三大技术是当今的热门研究领域之一,在农业领域控制、城市管理、环境监测等领域有重要的实用价值,具有十分广泛的应用前景。IPv6作为下一代IP协议正在逐步替代IPv4。无线传感器网络和IPv6的结合是当前研究的热点。本文基于轻量化IPv6协议栈为目的,通过分析IPv6报文以及无线传感器网络的特点,采用理论分析合理地提出了WSN中IPv6协议栈核心功能的剪裁方案。在试验中使用压缩的IPv6地址进行通信,得出一种适应于无线传感器网络运行的IPv6协议剪裁方案。     

一种基于预约的无线传感器网络MAC协议

无线传感器网络要求的能量高效,低延时,使得MAC协议的设计充满挑战。近来已经提出了很多基于簇的MAC协议,为减少冲突在簇内部采用TDMA方式来协调簇内各个节点的传输。提出了一种在采用簇结构的基础上,使用预约方式来发送数据的R-MAC（Reservation-MAC）协议。当争用节点少的时候,采用随机争用方式来预约数据的发送;在争用节点多的时候,采用时隙争用方式来预约数据的发送。分析表明,R-MAC能够有效地降低能耗和减少延迟。     

A centralized energy-efficient routing protocol for wireless sensor networks

Wireless sensor networks consist of small battery powered devices with limited energy resources. Once deployed, the small sensor nodes are usually inaccessible to the user, and thus replacement of the energy source is not feasible. Hence, energy efficiency is a key design issue that needs to be enhanced in order to improve the life span of the network. Several network layer protocols have been proposed to improve the effective lifetime of a network with a limited energy supply. In this article we propose a centralized routing protocol called base-station controlled dynamic clustering protocol (BCDCP), which distributes the energy dissipation evenly among all sensor nodes to improve network lifetime and average energy savings. The performance of BCDCP is then compared to clustering-based schemes such as low-energy adaptive clustering hierarchy (LEACH), LEACH-centralized (LEACH-C), and power-efficient gathering in sensor information systems (PEGASIS). Simulation results show that BCDCP reduces overall energy consumption and improves network lifetime over its comparatives.     

Time-diffusion synchronization protocol for wireless sensor networks

In the near future, small intelligent devices will be deployed in homes, plantations, oceans, rivers, streets, and highways to monitor the environment. These devices require time synchronization, so voice and video data from different sensor nodes can be fused and displayed in a meaningful way at the sink. Instead of time synchronization between just the sender and receiver or within a local group of sensor nodes, some applications require the sensor nodes to maintain a similar time within a certain tolerance throughout the lifetime of the network. The Time-Diffusion Synchronization Protocol (TDP) is proposed as a network-wide time synchronization protocol. It allows the sensor network to reach an equilibrium time and maintains a small time deviation tolerance from the equilibrium time. In addition, it is analytically shown that the TDP enables time in the network to converge. Also, simulations are performed to validate the effectiveness of TDP in synchronizing the time throughout the network and balancing the energy consumed by the sensor nodes.     

A region-based routing protocol for wireless mobile ad hoc networks

Flooding-based route discovery is widely assumed in existing routing protocols of wireless ad hoc networks. Network-wide flooding enables the discovery of optimal routes from sources to destinations; however, as all network nodes are required to participate in the relays of route request packets, substantial control overhead is inevitable. Some efficient broadcast schemes can suppress redundant packet relays, but they often suppress the discovery of optimal routes, too. In this article we propose to dynamically create a prerouting region between each source-destination pair and limit the propagations of route request packets only within this region. The prerouting region effectively restricts route discovery activities to the nodes that most likely constitute the optimal or near-optimal routes. Consequently, not only is route construction overhead significantly reduced; route optimality is also guaranteed. The article presents a region-based routing (REGR) protocol covering both new route formation cases and route update cases. Simulations show that our protocol is particularly beneficial to dense and large-scale mobile ad hoc networks.     

A PUF-based anonymous authentication protocol for wireless medical sensor networks

Wireless Networks - Wireless medical sensor networks (WMSNs) play a major role in remote medical monitoring systems. Generally, in a WMSN, professionals need to obtain real-time physiological data...     

An Aloha protocol for multihop mobile wireless networks

An Aloha-type access control mechanism for large mobile, multihop, wireless networks is defined and analyzed. This access scheme is designed for the multihop context, where it is important to find a compromise between the spatial density of communications and the range of each transmission. More precisely, the analysis aims at optimizing the product of the number of simultaneously successful transmissions per unit of space (spatial reuse) by the average range of each transmission. The optimization is obtained via an averaging over all Poisson configurations for the location of interfering mobiles, where an exact evaluation of signal over noise ratio is possible. The main mathematical tools stem from stochastic geometry and are spatial versions of the so-called additive and max shot noise processes. The resulting medium access control (MAC) protocol exhibits some interesting properties. First, it can be implemented in a decentralized way provided some local geographic information is available to the mobiles. In addition, its transport capacity is proportional to the square root of the density of mobiles which is the upper bound of Gupta and Kumar. Finally, this protocol is self-adapting to the node density and it does not require prior knowledge of this density.     

A dual-mode energy efficient encryption protocol for wireless sensor networks

This paper presents a novel link-layer encryption protocol for wireless sensor networks. The protocol design aims to reduce energy consumption by reducing security related communication overhead. This is done by merging security related data of consecutive packets. The merging (or combining packets) based on simple mathematical operations helps to reduce energy consumption by eliminating the requirement to send security related fields in headers and trailers. We name our protocol as the Compact Security Protocol referred to as C-Sec. In addition to energy savings, the C-Sec protocol also includes a unique security feature of hiding the packet header information. This feature makes it more difficult to trace the flow of wireless communication, and helps to minimize the cost of defending against replay attacks. We performed rigorous testing of the C-Sec protocol and compared it with well-known protocols including TinySec, MiniSec, SNEP and Zigbee. Our performance evaluation demonstrates that the C-Sec protocol outperforms other protocols in terms of energy savings. We also evaluated our protocol with respect to other performance metrics including queuing delay and error probability.     

MC-LMAC: A multi-channel MAC protocol for wireless sensor networks

In traditional wireless sensor network (WSN) applications, energy efficiency may be considered to be the most important concern whereas utilizing bandwidth and maximizing throughput are of secondary importance. However, recent applications, such as structural health monitoring, require high amounts of data to be collected at a faster rate. We present a multi-channel MAC protocol, MC-LMAC, designed with the objective of maximizing the throughput of WSNs by coordinating transmissions over multiple frequency channels. MC-LMAC takes advantage of interference and contention-free parallel transmissions on different channels. It is based on scheduled access which eases the coordination of nodes, dynamically switching their interfaces between channels and makes the protocol operate effectively with no collisions during peak traffic. Time is slotted and each node is assigned the control over a time slot to transmit on a particular channel. We analyze the performance of MC-LMAC with extensive simulations in Glomosim. MC-LMAC exhibits significant bandwidth utilization and high throughput while ensuring an energy-efficient operation. Moreover, MC-LMAC outperforms the contention-based multi-channel MMSN protocol, a cluster-based channel assignment method, and the single-channel CSMA in terms of data delivery ratio and throughput for high data rate, moderate-size networks of 100 nodes at different densities.     

Mechanisms and hierarchical topology for fast handover in wireless IP networks

We propose a mechanism to perform fast handover in IP-based wireless networks for real-time applications such as Internet telephony and videoconferencing. Our proposal is designed to reestablish the communication session traffic flow quickly and to minimize the service disruption delay that occurs during mobile IP handover. In this scheme, we propose two different mechanisms to handle micromobility and inter-subdomain mobility, respectively. Micromobility handover handles movements within the same subdomain. Inter-subdomain handover supports handovers between two adjacent subdomains. The reason for having several subdomains is to deploy the network over a wider area to keep the mobile user in the same network for as long as possible. The novelty of the scheme is to retransmit the buffered packets during micromobility handover and to use multicasting to reestablish traffic flow during inter-subdomain movement. The entire scheme is performed within a hierarchical topology based on next-generation IP networks. We analyze both micromobility and inter-subdomain mobility handovers, and display simulation results for both voice and video over IP for micromobility handover.     

A stable energy efficient clustering protocol for wireless sensor networks

Sensor networks comprise of sensor nodes with limited battery power that are deployed at different geographical locations to monitor physical events. Information gathering is a typical but an important operation in many applications of wireless sensor networks (WSNs). It is necessary to operate the sensor network for longer period of time in an energy efficient manner for gathering information. One of the popular WSN protocol, named low energy adaptive clustering hierarchy (LEACH) and its variants, aim to prolong the network lifetime using energy efficient clustering approach. These protocols increase the network lifetime at the expense of reduced stability period (the time span before the first node dies). The reduction in stability period is because of the high energy variance of nodes. Stability period is an essential aspect to preserve coverage properties of the network. Higher is the stability period, more reliable is the network. Higher energy variance of nodes leads to load unbalancing among nodes and therefore lowers the stability period. Hence, it is perpetually attractive to design clustering algorithms that provides higher stability, lower energy variance and are energy efficient. In this paper to overcome the shortcomings of existing clustering protocols, a protocol named stable energy efficient clustering protocol is proposed. It balances the load among nodes using energy-aware heuristics and hence ensures higher stability period. The results demonstrate that the proposed protocol significantly outperforms LEACH and its variants in terms of energy variance and stability period.