Integrating machine learning in ad hoc routing: A wireless adaptive routing protocol

The nodes in a wireless ad hoc network act as routers in a self‐configuring network without infrastructure. An application running on the nodes in the ad hoc network may require that intermediate nodes act as routers, receiving and forwarding data packets to other nodes to overcome the limitations of noise, router congestion and limited transmission power. In existing routing protocols, the ‘self‐configuring’ aspects of network construction have generally been limited to the construction of routes that minimize the number of intermediate nodes on a route while ignoring the effects that the resulting traffic has on the overall communication capacity of the network. This paper presents a context‐aware routing metric that factors the effects of environmental noise and router congestion into a single time‐based metric, and further presents a new cross‐layer routing protocol, called Warp‐5 (Wireless Adaptive Routing Protocol, Version 5), that uses the new metric to make better routing decisions in heterogeneous network systems. Simulation results for Warp‐5 are presented and compared to the existing, well‐known AODV (Ad hoc On‐Demand Distance Vector) routing protocol and the reinforcement‐learning based routing protocol, Q‐routing. The results show Warp‐5 to be superior to shortest path routing protocols and Q‐routing for preventing router congestion and packet loss due to noise. Copyright © 2011 John Wiley & Sons, Ltd.     

Adaptive reliable and congestion control routing protocol for MANET

In mobile ad hoc networks (MANETs), the packet loss can be caused either by link failure or by node failure. Moreover, the techniques for selecting the bypass route and avoiding congestion in the bypass route are rarely handled. To overcome these, in this paper, we propose an adaptive reliable and congestion control routing protocol to resolve congestion and route errors using bypass route selection in MANETs. The multiple paths are constructed. Among which, the shortest paths are found for efficient data transmission. The congestion is detected on the basis of utilization and capacity of link and paths. When a source node detects congestion on a link along the path, it distributes traffic over alternative paths by considering the path availability threshold and using a traffic splitting function. If a node cannot resolve the congestion, it signals its neighbors using the congestion indication bit. By using simulation, we show that that the proposed protocol is reliable and achieves more throughput with reduced packet drops and overhead.     

Improved neighbor detection algorithm for AODV routing protocol

In this letter, a problem related to the behavior of WLAN 802.11 b network cards when working in the ad hoc mode is described. This behavior was noticed during experimental evaluation of an ad hoc network that was using the AODV (ad hoc On-demand Distance Vector) routing protocol. The observed problem affects the neighbor detection algorithm of the AODV routing protocol and has a deteriorating impact on performance of ad hoc networks that use this protocol. An improvement of the neighbor detection algorithm based on the differentiation of good and bad neighbors using signal to noise ratio (SNR) value is proposed, described and experimentally verified.     

Optimal cluster-based routing scheme using node mobility in ad hoc networks

Ad hoc networks have a scalability problem. When the nodes of an ad hoc network increase in number or mobility, the amount of control traffic for routing increases and could cause traffic congestion. Cluster-based routing schemes have been proposed as a solution to this problem. Typical cluster-based ad hoc networks use a proactive routing scheme for intra-cluster routes and a reactive routing scheme for inter-cluster routes. In this study, we propose a new cluster-based routing scheme for ad hoc networks which makes use of the mobility of nodes. Nodes are divided into two groups on the basis of their mobility. For a route search within a cluster, a proactive routing scheme is used for low-mobility nodes and a flooding-based reactive routing scheme is used for high-mobility nodes. The required control traffic of the proposed scheme is analyzed and optimal parameters of the proposed scheme are derived from the analysis. The numerical results show that the proposed scheme produces far less control traffic than a typical cluster-based routing scheme.     

Congestion–distortion optimized video transmission over ad hoc networks

The performance of low-latency video streaming with multipath routing over ad hoc networks is studied. As the available transmission rate of individual links in an ad hoc network is typically limited due to power and bandwidth constraints, a single node transmitting multimedia data may impact the overall network congestion and may therefore need to limit its rate while striving for the highest sustainable video quality. For this purpose, optimal routing algorithms which seek to minimize congestion by optimally distributing traffic over multiple paths are attractive. To predict the end-to-end rate-distortion tradeoff, we develop a model which captures both the impact of encoder quantization and of packet loss due to network congestion on the overall video quality. The validity of the model is confirmed by network simulations performed with different routing algorithms, latency requirements and encoding structures.     

Opportunistic media access control and routing for delay-tolerant mobile ad hoc networks

In delay-tolerant mobile ad hoc networks, motion of network nodes, network sparsity and sporadic density can cause a lack of guaranteed connectivity. These networks experience significant link delay and their routing protocols must take a store-and-forward approach. In this paper, an opportunistic routing protocol is proposed, along with its compatible media access control, for non-real-time services in delay-tolerant networks. The scheme is mobility-aware such that each network node needs to know its own position and velocity. The media access control employs a four-fold handshake procedure to probe the wireless channel and cooperatively prioritize candidate nodes for packet replication. It exploits the broadcast characteristic of the wireless medium to utilize long-range but unreliable links. The routing process seizes opportunities of node contacts for data delivery. It takes a multiple-copy approach that is adaptive with node movements. Numerical results in mobile ad hoc networks and vehicular ad hoc networks show superior performance of the proposed protocol compared with other routing protocols. The mobility-aware media access control and routing scheme exhibits relatively small packet delivery delay and requires a modest amount of total packet replications/transmissions.     

Load Balanced Congestion Adaptive Routing for Randomly Distributed Mobile Adhoc Networks

In mobile ad hoc networks, congestion occurs due to limited sources of the network, which leads to packet losses, bandwidth degradation and wastes time and energy on congestion recovery. Various techniques have been developed in attempt to minimize congestion in uniformly distributed networks. In this paper, a load balanced congestion adaptive routing algorithm has been proposed for randomly distributed networks. In the proposed algorithm two metrics: traffic load density and life time associated with a routing path, have been used to determine the congestion status and weakest node of the route. The route with low traffic load density and maximum life time is selected for packet transmission.     

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 hybrid multiagent routing approach for wireless ad hoc networks

Wireless ad-hoc networks are infrastructureless networks that comprise wireless mobile nodes able to communicate each other outside wireless transmission range. Due to frequent network topology changes in one hand and the limited underlying bandwidth in the other hand, routing becomes a challenging task. In this paper we present a novel routing algorithm devoted for mobile ad hoc networks. It entails both reactive and proactive components. More precisely, the algorithm is based on ant general behavior, but differs from the classic ant methods inspired from Ant-Colony-Optimization algorithm [1]. We do not use, during the reactive phase, a broadcasting technique that exponentially increases the routing overhead, but we introduce a new reactive route discovery technique that considerably reduces the communication overhead. In the simulation results, we show that our protocol can outperform both Ad hoc On-demand Distance Vector (AODV) protocol [2], one of the most important current state-of-the-art algorithms, and AntHocNet protocol [5], one of the most important ant-based routing algorithms, in terms of end-to-end delay, packet delivery ratio and the communication overhead.     

一种基于跨层设计和蚁群优化的自组网负载均衡路由协议

针对大部分现有替代路径共同存在的替代路径老化和构建效率问题,本文提出了一种基于跨层设计和蚁群优化的负载均衡路由协议(CALRA),利用蚁群优化算法特有的信息素挥发方法实现对替代路径的老化问题,将蚁群优化和跨层优化方法结合起来解决自组网中的负载均衡问题,通过双向逐跳更新的方式较好的解决了替代路径构建效率问题,并将蚂蚁在所经过的各中间节点为路由表带来的信息素增量映射为蚂蚁离开源节点的距离、移动过程中所遇到的节点拥塞程度、节点当前信息素浓度和节点移动速度等各协议层的统计信息的函数,通过对各种信息所对应的参数赋予不同加权值的方法对概率路由表进行控制,改善了自组网中现有基于蚁群优化的路由协议中普遍存在的拥塞问题、捷径问题、收敛速度问题和引入的路由开销问题.仿真表明,CALRA在分组成功递交率、路由开销、端到端平均时延等方面具有优良性能,能很好地实现网络中的业务负载均衡.     

Security and performance enhancement of AODV routing protocol

A mobile ad hoc networks (MANET) is a decentralized, self‐organizing, infrastructure‐less network and adaptive gathering of independent mobile nodes. Because of the unique characteristics of MANET, the major issues to develop a routing protocol in MANET are the security aspect and the network performance. In this paper, we propose a new secure protocol called Trust Ad Hoc On‐demand Distance Vector (AODV) using trust mechanism. Communication packets are only sent to the trusted neighbor nodes. Trust calculation is based on the behaviors and activities information of each node. It is divided in to trust global (TG) and trust local (TL). TG is a trust calculation based on the total of received routing packets and the total of sending routing packets. TL is a comparison between total received packets and total forwarded packets by neighbor node from specific nodes. Nodes conclude the total trust level of its neighbors by accumulating the TL and TG values. The performance of Trust AODV is evaluated under denial of service/distributed denial of service (DOS/DDOS) attack using network simulator NS‐2. It is compared with the Trust Cross Layer Secure (TCLS) protocol. Simulation results show that the Trust AODV has a better performance than TCLS protocol in terms of end‐to‐end delay, packet delivery ratio, and overhead. Next, we improve the performance of Trust AODV using ant algorithm. The proposed protocol is called Trust AODV + Ant. The implementation of ant algorithm in the proposed secure protocol is by adding an ant agent to put the positive pheromone in the node if the node is trusted. Ant agent is represented as a routing packet. The pheromone value is saved in the routing table of the node. We modified the original routing table by adding the pheromone value field. The path communication is selected based on the pheromone concentration and the shortest path. Trust AODV + Ant is compared with simple ant routing algorithm (SARA), AODV, and Trust AODV under DOS/DDOS attacks in terms of performance. Simulation results show that the packet delivery ratio and throughput of the Trust AODV increase after using ant algorithm. However, in terms of end‐to‐end delay, there is no significant improvement. Copyright © 2014 John Wiley & Sons, Ltd.     

Congestion Control Performance of R-DSDV Protocol in Multihop Wireless Ad Hoc Networks

Ad hoc wireless networks are composed of mobile nodes communicating through wireless links, without any fixed backbone infrastructure. Frequent topology changes due to node mobility make routing in such dynamic networks a challenging problem. Moreover, successful message routing implies every mobile node is potentially capable of acting as a router, thus supporting store-and-forward mechanisms. However, resource limitations on these nodes also require a control on congestion due to message forwarding. In this paper, we consider our recently proposed randomized version of the well-known Destination-Sequenced Distance Vector (DSDV) routing protocol, referred to as R-DSDV, and validate its performance through extensive simulation experiments. Our results demonstrate that a probabilistic control on message traffic based on local tuning of protocol parameters is feasible, and that R-DSDV outperforms the basic DSDV protocol by significantly reducing the average queue size associated with each mobile node and hence the average packet delay.     

Routing in Sparse Vehicular Ad Hoc Wireless Networks

A vehicular ad hoc network (VANET) may exhibit a bipolar behavior, i.e., the network can either be fully connected or sparsely connected depending on the time of day or on the market penetration rate of the wireless communication devices. In this paper, we use empirical vehicle traffic data measured on 1-80 freeway in California to develop a comprehensive analytical framework to study the disconnected network phenomenon and its network characteristics. These characteristics shed light on the key routing performance metrics of interest in disconnected VANETs, such as the average time taken to propagate a packet to disconnected nodes (i.e., the re-healing time). Our results show that, depending on the sparsity of vehicles or the market penetration rate of cars using Dedicated Short Range Communication (DSRC) technology, the network re-healing time can vary from a few seconds to several minutes. This suggests that, for vehicular safety applications, a new ad hoc routing protocol will be needed as the conventional ad hoc routing protocols such as Dynamic Source Routing (DSR) and Ad Hoc On-Demand Distance Vector Routing (AODV) will not work with such long re-healing times. In addition, the developed analytical framework and its predictions provide valuable insights into the VANET routing performance in the disconnected network regime.     

Load Balancing Technique for Congestion Control Multipath Routing Protocol in MANETs

A mobile ad hoc network (MANET) is a collection of wireless mobile nodes that can communicate without a central controller or fixed infrastructure. Due to node mobility, designing a routing protocol to provide an efficient and suitable method to route the data with less energy consumption, packet drop and to prolong the network lifetime has become a challenging issue in MANETs. In MANETs, reducing energy consumption and packet loss involves congestion control and load balancing techniques. Thus, this paper introduces an efficient routing technique called the multipath load balancing technique for congestion control (MLBCC) in MANETs to efficiently balance the load among multiple paths by reducing the congestion. MLBCC introduces a congestion control mechanism and a load balancing mechanism during the data transmission process. The congestion control mechanism detects the congestion by using an arrival rate and an outgoing rate at a particular time interval T. The load balancing mechanism selects a gateway node by using the link cost and the path cost to efficiently distribute the load by selecting the most desirable paths. For an efficient flow of distribution, a node availability degree standard deviation parameter is introduced. Simulation results of MLBCC show the performance improvements in terms of the control overhead, packet delivery ratio, average delay and packet drop ratio in comparison with Fibonacci sequence multipath load balancing, stable backbone-based multipath routing protocol and ad hoc on demand multipath distance vector routing. In addition, the results show that MLBCC efficiently balances the load of the nodes in the network.

     

Safari: A self-organizing, hierarchical architecture for scalable ad hoc networking

As wireless devices become more pervasive, mobile ad hoc networks are gaining importance, motivating the development of highly scalable ad hoc networking techniques. In this paper, we give an overview of the Safari architecture for highly scalable ad hoc network routing, and we present the design and evaluation of a specific realization of the Safari architecture, which we call Masai. We focus in this work on the scalability of learning and maintaining the routing state necessary for a large ad hoc network. The Safari architecture provides scalable ad hoc network routing, the seamless integration of infrastructure networks when and where they are available, and the support of self-organizing, decentralized network applications. Safari’s architecture is based on (1) a self-organizing network hierarchy that recursively groups participating nodes into an adaptive, locality-based hierarchy of cells; (2) a routing protocol that uses a hybrid of proactive and reactive routing information in the cells and scales to much larger numbers of nodes than previous ad hoc network routing protocols; and (3) a distributed hash table grounded in the network hierarchy, which supports decentralized network services on top of Safari. We evaluate the Masai realization of the Safari architecture through analysis and simulations, under varying network sizes, fraction of mobile nodes, and offered traffic loads. Compared to both the DSR and the L+ routing protocols, our results show that the Masai realization of the Safari architecture is significantly more scalable, with much higher packet delivery ratio and lower overhead.     

Reducing Latency and Overhead of Route Repair with Controlled Flooding

Ad hoc routing protocols that use broadcast for route discovery may be inefficient if the path between any source–destination pair is frequently broken. We propose and evaluate a simple mechanism that allows fast route repair in on demand ad hoc routing protocols. We apply our proposal to the Ad hoc On-demand Distance Vector (AODV) routing protocol. The proposed system is based on the Controlled Flooding (CF) framework, where alternative routes are established around the main original path between source–destination pairs. With alternative routing, data packets are forwarded through a secondary path without requiring the source to re-flood the whole network, as may be the case in AODV. We are interested in one-level alternative routing. We show that our proposal reduces the connection disruption probability as well as the frequency of broadcasts.     

On-demand loop-free routing with link vectors

We present the on-demand link vector (OLIVE) protocol, a routing protocol for ad hoc networks based on link-state information that is free of routing loops and supports destination-based packet forwarding. Routers exchange routing information reactively for each destination in the form of complete paths, and each node creates a labeled source graph based on the paths advertised by its neighbors. A node originates a broadcast route request (RREQ) to obtain a route for a destination for which a complete path does not exist in its source graph. When the original path breaks, a node can select an alternative path based on information reported by neighbors, and a node can send a unicast RREQ to verify that the route is still active. A node that cannot find any alternate path to a destination sends route errors reliably to those neighbors that were using it as next hop to the destination. Using simulation experiments in ns2, OLIVE is shown to outperform dynamic source routing, ad hoc on-demand distance vector, optimized link-state routing protocol, and topology broadcast based on reverse-path forwarding, in terms of control overhead, throughput, and average network delay, while maintaining loop-free routing with no need for source routes.     

Lightweight,latency‐aware routing for data compression in wireless sensor networks with heterogeneous traffics

In many applications and scenarios, sensors have to regularly report what they monitor from the environment and quickly notify the sink node of event occurrence in the sensing field. An in‐network data reduction technique, such as data aggregation and data compression, can help diminish the amount of data sent from sensors, which not only saves the network bandwidth but also preserves sensors' energy. However, such technique does not consider packet latency because of the aggregation or compression operation. When some sensors generate regular reports in lower data rates, their packets have to spend longer time to be aggregated or compressed, resulting in higher packet delays. Besides, when events occur, the network could suffer from instant congestion due to the generation of numerous event notifications. Motivated with the aforementioned observations, the paper develops a lightweight, latency‐aware routing for data compression (L2DC) scheme to reduce packet latency when applying the compression technique, to reduce the amount of data generated from sensors. L2DC gives event notifications a higher priority over regular reports and eliminates unnecessary notifications to avoid bursty network congestion. In addition, L2DC facilitates the data compression process by allowing each sensor to determine whether to keep packets for compression locally or to send them to a neighbor to be compressed in a distributed manner. Our L2DC scheme can be easily built on most ad hoc and sensor routing protocols because it provides auxiliary redundant packet elimination and relay node selection mechanisms to reduce packet latency. By using the ad hoc on‐demand distance vector protocol as the example, simulation results demonstrate the effectiveness of the L2DC scheme. Copyright © 2015 John Wiley & Sons, Ltd.     

An improved distance‐based ant colony optimization routing for vehicular ad hoc networks

Vehicular ad hoc network (VANET) has earned tremendous attraction in the recent period due to its usage in a wireless intelligent transportation system. VANET is a unique form of mobile ad hoc network (MANET). Routing issues such as high mobility of nodes, frequent path breaks, the blind broadcasting of messages, and bandwidth constraints in VANET increase communication cost, frequent path failure, and overhead and decrease efficiency in routing, and shortest path in routing provides solutions to overcome all these problems. Finding the shortest path between source and destination in the VANET road scenario is a challenging task. Long path increases network overhead, communication cost, and frequent path failure and decreases routing efficiency. To increase efficiency in routing a novel, improved distance‐based ant colony optimization routing (IDBACOR) is proposed. The proposed IDBACOR determines intervehicular distance, and it is triggered by modified ant colony optimization (modified ACO). The modified ACO method is a metaheuristic approach, motivated by the natural behavior of ants. The simulation result indicates that the overall performance of our proposed scheme is better than ant colony optimization (ACO), opposition‐based ant colony optimization (OACO), and greedy routing with ant colony optimization (GRACO) in terms of throughput, average communication cost, average propagation delay, average routing overhead, and average packet delivery ratio.