Routing protocol based on social characteristics for opportunistic networks简

Opportunistic networks are derived from delay tolerant networks, where mobile nodes have no end-to-end connections. Nodes are represented by people, which means that opportunistic networks can be regarded as social networks. Human mobility plays an important role in affecting the performance of forwarding protocols in social networks, furthermore, the trajectory of people＇s movements are driven by social characteristics. However, current routing protocols rely on simple mobility models, and rarely consider social characteristics. Considering two heterogeneous network models, an social opportunistic networks routing（SONR） was proposed which brings an adapted discrete Markov chain into nodes＇ mobility model and calculates the transition probability between successive status. Comparison was made between Spray, Wait and Epidemic protocol. Simulation show that SONR can improve performance on delivery ratio, delivery latency and network overhead, meanwhile. SONR approaches the performance of Epidemic routing.     

Fuzzy Logic Based Distance and Energy-Aware Routing Protocol in Delay-Tolerant Mobile Sensor Networks

In challenged networks such as Wireless Sensor Networks, limitations such as nodes mobility, short radio range and sparse network density can prevent communications among nodes. Consequently, it can result in long delays in exchanging messages among nodes. Designing Delay-Tolerant Networks is considered to be an approach for dealing with lengthy breakdown of communication between nodes. Using multi-replica methods seems rational for these networks. However, a majority of these methods inject a large amount of replications of a message in the network so as to enhance message delivery probability which consequently leads to the loss of energy and reduction of network efficiency. Two major issues should be considered to achieve data delivery in such challenging networking environments: a routing strategy for the network and a buffer management policy. This study proposes a new routing protocol called Fuzzy-Logic based Distance and Energy Aware Routing protocol (FLDEAR) in delay tolerant mobile sensor network. A FLDEAR is a distance and energy aware protocol that reduces the number of message replications and uses two fuzzy inference systems in routing and buffer management. The results of conducted simulations indicated that this routing algorithm can be used for enhancing data packet delivery ratios and reducing data transmission overhead than several current Delay-Tolerant Mobile Sensor Networks routing protocols.     

Contention aware mobility prediction routing for intermittently connected mobile networks

This paper introduces a novel multi-copy routing protocol, called predict and forward (PF), for delay tolerant networks, which aims to explore the possibility of using mobile nodes as message carriers for end-to-end delivery of the messages. With PF, the message forwarding decision is made by manipulating the probability distribution of future inter-contact and contact durations based on the network status, including wireless link condition and nodal buffer availability. In particular, PF is based on the observations that the node mobility behavior is semi-deterministic and could be predicted once there is sufficient mobility history information. We implemented the proposed protocol and compared it with a number of existing encounter-based routing approaches in terms of delivery delay, delivery ratio, and the number of transmissions required for message delivery. The simulation results show that PF outperforms all the counterpart multi-copy encounter-based routing protocols considered in the study.     

HVE-mobicast: a hierarchical-variant-egg-based mobicast routing protocol for wireless sensornets

In this paper, we propose a new mobicast routing protocol, called the HVE-mobicast (hierarchical-variant-egg-based mobicast) routing protocol, in wireless sensor networks (WSNs). Existing protocols for a spatiotemporal variant of the multicast protocol called a “mobicast” were designed to support a forwarding zone that moves at a constant velocity, \(\stackrel{\rightarrow}{v}\), through sensornets. The spatiotemporal characteristic of a mobicast is to forward a mobicast message to all sensor nodes that are present at time t in some geographic zone (called the forwarding zone) Z, where both the location and shape of the forwarding zone are a function of time over some interval (t _start ,t _end ). Mobicast routing protocol aims to provide reliable and just-in-time message delivery for a mobile sink node. To consider the mobile entity with the different moving speed, a new mobicast routing protocol is investigated in this work by utilizing the cluster-based approach. The message delivery of nodes in the forwarding zone of the HVE-mobicast routing protocol is transmitted by two phases; cluster-to-cluster and cluster-to-node phases. In the cluster-to-cluster phase, the cluster-head and relay nodes are distributively notified to wake them up. In the cluster-to-node phase, all member nodes are then notified to wake up by cluster-head nodes according to the estimated arrival time of the delivery zone. The key contribution of the HVE-mobicast routing protocol is that it is more power efficient than existing mobicast routing protocols, especially by considering different moving speeds and directions. Finally, simulation results illustrate performance enhancements in message overhead, power consumption, needlessly woken-up nodes, and successful woken-up ratio, compared to existing mobicast routing protocols.     

An Improved Routing Algorithm Based on Social Link Awareness in Delay Tolerant Networks

The routing efficiency in delay tolerant networks is degraded due to intermittent connection and high latency. Additionally, socially selfish nodes in social networks refuse to provide message forwarding service since there are limited resources. To solve these problems, an improved routing algorithm based on the social link awareness is proposed. In this algorithm, multiple social features of the nodes’ behaviors are utilized to quantify the nodes pairs’ social links. The social links of the nodes pairs are computed based on their encounter history. These social links can be used to construct the friendship communities of the nodes. The intra-community and inter-community forwarding mechanisms are implemented to raise the successful delivery ratio with low overhead and decrease the transmission delay. Simulation results show that the proposed algorithm shortens the routing delay and increases the successful delivery ratio, thereby improving the routing efficiency.     

Enhanced fuzzy logic‐based spray and wait routing protocol for delay tolerant networks

Delay tolerant networks are a class of ad hoc networks that enable data delivery even in the absence of end‐to‐end connectivity between nodes, which is the basic assumption for routing in ad hoc networks. Nodes in these networks work on store‐carry and forward paradigm. In addition, such networks make use of message replication as a strategy to increase the possibility of messages reaching their destination. As contact opportunities are usually of short duration, it is important to prioritize scheduling of messages. Message replication may also lead to buffer congestion. Hence, buffer management is an important issue that greatly affects the performance of routing protocols in delay tolerant networks. In this paper, Spray and Wait routing protocol, which is a popular controlled replication‐based protocol for delay tolerant networks, has been enhanced using a new fuzzy‐based buffer management strategy Enhanced Fuzzy Spray and Wait Routing, with the aim to achieve increased delivery ratio and reduced overhead ratio. It aggregates three important message properties namely number of replicas of a message, its size, and remaining time‐to‐live, using fuzzy logic to determine the message priority, which denotes its importance with respect to other messages stored in a node's buffer. It then intelligently selects messages to schedule when a contact opportunity occurs. Because determination of number of replicas of a message in the network is a difficult task, a new method for estimation of the same has been proposed. Simulation results show improved performance of enhanced fuzzy spray and wait routing in terms of delivery ratio and resource consumption. Copyright © 2014 John Wiley & Sons, Ltd.     

机会网络中基于摆渡节点与簇节点相互协作的路由机制

机会网络是一种不需要在源节点和目的节点之间存在完整路径,利用节点移动带来的相遇机会实现网络通信的延迟容忍自组织网络,它以“存储-携带-处理-转发”的模式进行.为实现互不相交簇间的信息传输,本文设计了一种带阈值的簇移动模型CMMT,并提出了一种基于摆渡（Ferry）节点与簇节点协作的路由算法（CBSW）.该算法减少了冗余的通信和存储开销,以及在Spray阶段簇节点没有遇到目的节点或摆渡节点,进入Wait阶段携带消息的节点采用直接分发方式只向目的节点传输等问题.仿真实验表明,CBSW算法能够增加传输成功率,减少网络开销和传输延迟.     

Efficient on-demand routing for mobile ad hoc wireless access networks

In this paper, we consider a mobile ad hoc wireless access network in which mobile nodes can access the Internet via one or more stationary gateway nodes. Mobile nodes outside the transmission range of the gateway can continue to communicate with the gateway via their neighboring nodes over multihop paths. On-demand routing schemes are appealing because of their low routing overhead in bandwidth restricted mobile ad hoc networks, however, their routing control overhead increases exponentially with node density in a given geographic area. To control the overhead of on-demand routing without sacrificing performance, we present a novel extension of the ad hoc on-demand distance vector (AODV) routing protocol, called LB-AODV, which incorporates the concept of load-balancing (LB). Simulation results show that as traffic increases, our proposed LB-AODV routing protocol has a significantly higher packet delivery fraction, a lower end-to-end delay and a reduced routing overhead when compared with both AODV and gossip-based routing protocols.     

Multipath Security Aware Routing Protocol for MANET Based on Trust Enhanced Cluster Mechanism for Lossless Multimedia Data Transfer

The dynamic nature of mobile nodes of ad hoc network is mostly affected by security problems which reduce data forwarding rate in multimedia sources. Due to the rapid growth of wireless applications, the different multitalented routing protocols are proposed in recent years. But the recent protocols are not efficient for multimedia applications, till now, specific security aware routing protocols are not proposed for multimedia data transfers. In this paper, we proposed trust enhanced cluster based multipath routing (TECM) algorithm. We use energy efficient PSO algorithm used to create cluster formation and cluster head, super cluster head are selected from trust values, which compute form proposed TECM algorithm. The multi trust factors are used for trust computation, such as frame/packet loss ratio, frame/packet forward energy, frame/packet receiving energy, routing overhead, received signal strength, frame/packet forward rate, average forward delay and protocol deviation flag. We then combine proposed TECM algorithm with standard multipath OLSR protocol (TECM-OLSR) to analyze the performance of proposed algorithm. The simulated results show that proposed TECM-OLSR protocol is very effective in terms of loss and delivery rate, delay, routing overhead and network lifetime compare to FPNT-OLSR.     

基础设施增强的DTN路由协议

针对间歇性连通的移动网络环境,提出了一种新的DTN路由协议IEDR。其整合以往DTN路由算法中的设计经验,充分利用节点间相遇的机会交换数据,提高数据传达率并降低传输延迟,同时将资源开销控制在可接受的范围内。IEDR 还尝试将无线接入点作为辅助数据传播的有效途径,利用接入点间高速互联的特性为数据在广大地域内的高效传播提供便利。仿真结果表明,与一些经典路由协议相比,IEDR达到了更好的效能。     

Weighted dominating set based routing for ad hoc communications in emergency and rescue scenarios

Disasters create emergency situations and the services provided must be coordinated quickly via a communication network. Mobile adhoc networks (MANETs) are suited for ubiquitous communication during emergency rescue operations, since they do not rely on infrastructure. The route discovery process of on-demand routing protocols consumes too much bandwidth due to high routing overhead. Frequent route changes also results in frequent route computation process. Energy efficiency, quick response time, and scalability are equally important for routing in emergency MANETs. In this paper, we propose an energy efficient reactive protocol named Weighted-CDSR for routing in such situations. This protocol selects a subset of network nodes named Maximum Weighted Minimum Connected Dominating Set (MWMCDS) based on weight, which consists of link stability, mobility and energy. The MWMCDS provides the overall network control and data forwarding support. In this protocol, for every two nodes u and v in the network there exists a path between u and v such that all intermediate nodes belong to MWMCDS. Incorporating route stability into routing reduces the frequency of route failures and sustains network operations over an extended period of time. With fewer nodes providing overall network control and data forwarding support, the proposed protocol creates less interference and consumes less energy. The simulation results show that the proposed protocol is superior to other protocols in terms of packet delivery ratio, control message overhead, transmission delay and energy consumption.     

Performance Analysis of Adaptive Routing Structure for Wireless Sensor Network Based on Load Balancing

Wireless sensor network consists of sensor nodes with battery operated device. The key challenges in the wireless sensor network are energy consumption and routing optimization. This work presents the cluster based load balancing (CBLB) routing protocol. The proposed routing protocol is used to minimize the energy consumption and increase the routing performance. It avoids the routing robustness, delay and increases the delivery rate and network performance. In existing techniques, different routing protocols such as LEACH, HEED and MESTER were used to increase the network performance and to decrease the energy consumption. But these existing techniques did not satisfy the performance requirements of wireless sensor networks. Hence, there is a requirement to develop a technique that meets the QoS requirements and needs of wireless sensor network. The proposed CBLB routing protocol creates a cluster head in the decentralized network and the cluster head will be used to distribute the workload evenly to the cluster members for reducing the energy consumption in wireless sensor network. Experimental results analyze the performance of the proposed protocol with the different existing protocols. The proposed protocol achieves high throughput, delivery rate and reduces the energy consumption, delay and routing overhead.     

Improving protocol robustness in ad hoc networks through cooperative packet caching and shortest multipath routing

A mobile ad hoc network is an autonomous system of infrastructure-less, multihop, wireless mobile nodes. Reactive routing protocols perform well in this environment due to their ability to cope quickly against topological changes. This paper proposes a new routing protocol named CHAMP (caching and multiple path) routing protocol. CHAMP uses cooperative packet caching and shortest multipath routing to reduce packet loss due to frequent route failures. We show through extensive simulation results that these two techniques yield significant improvement in terms of packet delivery, end-to-end delay and routing overhead. We also show that existing protocol optimizations employed to reduce packet loss due to frequent route failures, namely local repair in AODV and packet salvaging in DSR, are not effective at high mobility rates and high network traffic.     

A dynamic cross-layer routing protocol for Mobile Ad hoc Networks

A new cross-layer routing protocol, named Dynamic Packet Guidance (DPG), is introduced for Mobile Ad hoc Networks (MANETs). Simulation results show that DPG is quite useful for usage in dense networks of mobile nodes, with medium-to-high speeds, and low-to-medium load. In these scenarios, DPG provides a superior performance compared to several well-known ad hoc routing protocols. The low end-to-end delay and smaller overhead that DPG achieves in such scenarios positively impacts the scalability of MANETs and reduces the energy requirements of nodes in such networks. DPG also shows immunity to failing nodes, as it operates consistently almost independently of failing nodes up to a certain ratio.     

Information Theoretic Analysis of Proactive Routing Overhead in Mobile Ad Hoc Networks

This paper considers basic bounds on the overhead of link-state protocols in mobile ad hoc networks. Hierarchical protocols are known for their good scalability properties, and hence this paper considers a two-level hierarchical protocol. In such protocols, nodes need to keep track of shortest path information, link states and cluster membership. Two types of overheads are considered; the memory needed to store routing-related information, including link-states and cluster membership, and the control messages that need to be exchanged to keep track of the changes in the network. Memory overhead is important practically for dimensioning network nodes, while message routing overhead is important since it reduces the effective capacity of the network to carry user data (vis-a-vis control data). The scalability properties of the message routing overhead are analyzed for different modes of network scaling. Practical implications, such as optimal cluster size, average/fixed memory requirement and routing protocol parameter selections are discussed.     

Secure Multi-copy Routing in Compromised Delay Tolerant Networks

Routing in delay tolerant networks (DTNs) is challenging due to their unique characteristics of intermittent node connectivity. Different protocols (single-, multi-copy, erasure-coding-based etc.) utilizing store-carry-and-forward paradigm have been proposed to achieve routing of messages in such environments by opportunistic message exchanges between nodes that are in the communication range of each other. The sparsity and distributed nature of these networks together with the lack of stable connectivity between source destination pairs make these networks vulnerable to malicious nodes which might attempt to learn the content of the messages being routed between the nodes. In this paper, we study DTNs in which malicious nodes are present, to which we refer to as compromised DTNs. We discuss and analyze the effects of presence of malicious nodes on routing of messages in compromised DTNs. We propose a two period routing approach which aims at achieving the desired delivery ratio by a given delivery deadline in presence of malicious nodes. Our simulation results with both random networks and real DTN traces show that, with proper parameter setting, the proposed method can achieve delivery ratios which surpass those reached by other algorithms by a given delivery deadline.     

CSI: A paradigm for behavior-oriented profile-cast services in mobile networks

We propose a new behavior-oriented communication paradigm in mobile networks, profile-cast, motivated by tight user-network coupling in mobile societies. In this novel paradigm, messages are sent to sender-specified target profiles, instead of machine IDs. We present a systematic framework for such services. First, we analyze the spatio-temporal stability of user mobility profiles constructed from empirical data sets, and they turn out to be surprisingly stable. The similarity of the current mobility profile of a user to its future mobility profile remains above 0.6 for five weeks, while the correlation coefficient of the similarity metrics between a user pair at different time instants is above 0.5 for two weeks. Second, we present a protocol for the profile-cast service, named CSI, and provide a fully distributed solution utilizing behavioral profile space gradients and small world structures to selectively diffuse information across the network towards the intended recipients.Leveraging stability in user behaviors, the two modes of CSI achieve good performance compared to the theoretical optimal protocols. Both CSI:Target mode and CSI:Dissemination mode achieve more than 94% delivery ratio. Comparing with the delay-optimal protocol, they show no more than 47% and 32% more delay, respectively, with at most 10% more transmission overhead. Comparing with the overhead-optimal protocol, they use no more than 7% more overhead while achieving dramatic improvement in delay (up to 150% less). Both CSI:T and CSI:D significantly outperform the epidemic routing, using less than 7% overhead, and variants of random walk, where CSI:T doubles the delivery ratio using less overhead, and CSI:D shows at least 50% less delay under similar overhead.We believe the profile-cast paradigm would enable many behavior-oriented services efficiently, such as targeted announcements and profile-based alert notifications, in various mobile networks.     

Ad Hoc网络中拓扑结构对路由协议性能的影响

介绍了Ad Hoc网络中常见的三种路由协议DSDV、DSR和AODV,针对网络拓扑结构的变化,设计了两种仿真方案,利用NS2仿真工具对三个协议进行了仿真。通过分析报文投递率和平均端到端时延比较了三个协议的性能。仿真结果表明,AODV具有优秀的综合性能,更适合于节点移动速度快且网络拓扑结构变化频繁的网络。     

An altruism‐based trust‐dependent message forwarding protocol for opportunistic networks

In opportunistic networks (OppNets), which are characterized by intermittent end‐to‐end connections, the messages are routed in a store‐carry‐and‐forward fashion using the locally inferred knowledge about the behavior of nodes. As such, most OppNets routing protocols use social metrics that are dependent on the nodes' past information. But the participation of nodes in the message forwarding process is not guaranteed without incentivizing them because most nodes are reluctant in sharing their private resources for public uses. In this paper, some socially derived psychological attributes of a node are introduced to ensure their trustworthy participation in the message forwarding process, leading to the design of an altruism‐dependent trust‐based data forwarding mechanism for OppNets (called ATDTN). In this protocol, each node is associated with a dynamically changing altruism value representing its trust in the network, which is used to determine its status with regard to its participation in message forwarding. Through trace‐driven simulations using the ONE simulator, it is shown that ATDTN outperforms IronMan and SimBet protocols for routing in OppNets (respectively, 18% and 48% improvement), in terms of delivery ratio, end‐to‐end delay, overhead count, and average number of hops, under varying buffer size and time‐to‐live.     

QoS routing through alternate paths in wireless ad hoc networks

Quality of service (QoS) routing plays an important role in QoS provisioning for mobile ad hoc networks. This work studies the issue of route selection subject to QoS constraint(s). Our method searches for alternate routes with satisfied QoS requirement(s) to accommodate each communication request when the shortest path connecting the source–destination pair of the request is not qualified. In order to effectively reduce protocol overhead, a directed search mechanism is designed to limit the breadth of the searching scope, which aims at achieving a graceful tradeoff between the success probability in QoS route acquisition and communication overhead. Efficient hop‐by‐hop routing protocols are designed for route selection subject to delay and bandwidth constraint, respectively. Simulation results show that the designed protocols can achieve high performance in acquiring QoS paths and in efficient resource utilization with low control overhead. Copyright © 2004 John Wiley & Sons, Ltd.