Reliable adaptive multicast protocol in wireless Ad hoc networks

In wireless ad hoe network environments, every link is wireless and every node is mobile. Those features make data lost easily as well as multicasting inefficient and unreliable. Moreover, Efficient and reliable multicast in wireless ad hoe network is a difficult issue. It is a major challenge to transmission delays and packet losses due to link changes of a multicast tree at the provision of high delivery ratio for each packet transmission in wireless ad hoe network environment. In this paler, we propose and evaluate Reliable Adaptive Multicast Protocol （RAMP） based on a relay node concept. Relay nodes are placed along the multieast tree. Data recovery is done between relay nodes. RAMP supports a reliable multicasting suitable for mobile ad hoe network by reducing the number of packet retransmissions. We compare RAMP with SRM （Scalable Reliable Multicast）. Simulation results show that the RAMP has high delivery ratio and low end-to-end delay for packet transmsission.

Virtual reality mobility model for wireless ad hoc networks

For wireless ad hoc networks simulation, node＇s mobility pattern and traffic pattern are two key elements. A new simulation model is presented based on the virtual reality collision detection algorithm in obstacle environment, and the model uses the path planning method to avoid obstacles and to compute the node＇s moving path. Obstacles also affect node＇s signal propagation. Considering these factors, this study implements the mobility model for wireless ad hoc networks. Simulation results show that the model has a significant impact on the performance of protocols.

Linear Network Coding Based Fast Data Synchronization for Wireless Ad Hoc Networks with Controlled Topology

Fast data synchronization in wireless ad hoc networks is a challenging and critical problem.It is fundamental for efficient information fusion,control and decision in distributed systems.Previously,distributed data synchronization was mainly studied in the latency-tolerant distributed databases,or assuming the general model of wireless ad hoc networks.In this paper,we propose a pair of linear network coding(NC)and all-to-all broadcast based fast data synchronization algorithms for wireless ad hoc networks whose topology is under operator’s control.We consider both data block selection and transmitting node selection for exploiting the benefits of NC.Instead of using the store-and-forward protocol as in the conventional uncoded approach,a compute-and-forward protocol is used in our scheme,which improves the transmission efficiency.The performance of the proposed algorithms is studied under different values of network size,network connection degree,and per-hop packet error rate.Simulation results demonstrate that our algorithms significantly reduce the times slots used for data synchronization compared with the baseline that does not use NC.

Delay-Based Cross-Layer QoS Scheme for Video Streaming in Wireless Ad Hoc Networks

With correlating with human perception, quality of experience(Qo E) is also an important measurement in evaluation of video quality in addition to quality of service(Qo S). A cross-layer scheme based on Lyapunov optimization framework for H.264/AVC video streaming over wireless Ad hoc networks is proposed, with increasing both Qo E and Qo S performances. Different from existing works, this scheme routes and schedules video packets according to the statuses of the frame buffers at the destination nodes to reduce buffer underflows and to increase video playout continuity. The waiting time of head-ofline packets of data queues are considered in routing and scheduling to reduce the average end-to-end delay of video sessions. Different types of packets are allocated with different priorities according to their generated rates under H.264/AVC. To reduce the computational complexity, a distributed media access control policy and a power control algorithm cooperating with the media access policy are proposed. Simulation results show that, compared with existing schemes, this scheme can improve both the Qo S and Qo E performances. The average peak signal-to-noise ratio(PSNR) of the received video streams is also increased.

IP ADDRESS AUTOCONFIGURATION FOR WIRELESS AD HOC NETWORKS

A novel mechanism was specified by which a node in ad hoc network may autoconfigure an IP address which is unique throughout the mobile ad hoc network. This new algorithm imposes less and constant overhead and delay in obtaining an IP address, and fully utilizes the available addresses space of an ad hoc network, and independent of the existing routing protocol, and less prone to security threats. Moreover, a new Join/Leave mechanism was proposed as an enhancement to the new IP address autoconfiguration algorithm, to support the overall operation of the existing routing protocol of wireless ad hoc networks.

Using Bayesian Game Model for Intrusion Detection in Wireless Ad Hoc Networks

Wireless ad ho network is becoming a new research fronter, in which security is an important issue. Usually some nodes act maliciously and they are able to do different kinds of Denial of Service (Dos). Because of the limited resource, intrusion detection system (IDS) runs all the time to detect intrusion of the attacker which is a costly overhead. In our model, we use game theory to model the interactions between the intrusion detection system and the attacker, and a realistic model is given by using Bayesian game. We solve the game by finding the Bayesian Nash equilibrium. The results of our analysis show that the IDS could work intermittently without compromising on its effectiveness. At the end of this paper, we provide an experiment to verify the rationality and effectiveness of the proposed model.

Subarea Tree Routing (STR) in Multi-hop Wireless Ad hoc Networks

Subarea Tree Routing (STR), a new routing protocol for multi-hop wireless ad hoc networks, is proposed. The novelty of the STR protocol is to divide the whole network into many subareas constructed as a result of establishing subarea trees. Its main idea is to identify root nodes by manual configuration or auto-discovery process firstly, then the root nodes originate the process of establishing subarea trees, and finally each node either joins in a subarea tree or become an interconnect node. STR belongs to hierarchical routing protocol and does not attempt to consistently maintain routing information in every node. Furthermore, through the use of tree’s intrinsic routing function, the STR protocol exhibits hybrid behavior of proactive and on-demand routing protocols. We prove the correctness of STR, and our simulation results show that the pro-posed scheme achieves lower route discovery delays, lower route discovery load and better performance of normalized routing load in large, mobile, ad hoc networks as compared with AODV.

An Efcient Hop Count Routing Protocol for Wireless Ad Hoc Networks

An efcient hop count route fnding approach for mobile ad hoc network is presented in this paper.It is an adaptive routing protocol that has a tradeof between transmission power and hop count for wireless ad hoc networks.During the route fnding process,the node can dynamically assign transmission power to nodes along the route.The node who has received route request message compares its power with the threshold power value,and then selects a reasonable route according to discriminating algorithms.This algorithm is an efective solution scheme to wireless ad hoc networks through reasonably selected path to reduce network consumption.Simulation results indicate that the proposed protocol can deliver better performances with respect to energy consumption and end-to-end delay.

LaConf:A Localized Address Autoconfiguration Scheme for Wireless Ad Hoc Networks

We propose a localized address autoconfiguration （LaConf） scheme for wireless ad hoc networks. Address allocation information is maintained on the network border nodes, called addressing agents （AAs）, which are locally identified by a geographic routing protocol GFG （Greedy-FACE-Greedy）. When a node joins the network, it acquires an address from a neighboring AA （if any exists） by local communication or from the head AA （a geographic extreme AA） by GFG-based multi-hop communication. A Geographic Hash Table （GHT） is adopted for duplicate address detection. Each address is hashed to a unique location in the network field, and the associated assignment information is stored along the face perimeter enclosing that location （in the planar graph）. When a node receives an address assignment, it consults with the perimeter nodes around the hash location of the assigned address about any conflicts. AAs detect network partitions and merger locally according to neighborhood change and trigger AA re-selection and network re-configuration （if necessary）. We propose to apply a Connected Dominating Set （CDS） to improve the performance. We also evaluate LaConf through simulation using different planar graphs.

RMAC： A Reliable MAC Protocol Supporting Multicast for Wireless Ad Hoc Networks

This paper presents a new reliable MAC protocol called “RMAC”supporting reliable multicast for wireless ad hoc networks. By utilizing the busy tones to realize the multicast reliability, RMAC has three novelties： （1） it uses a variablelength control frame to stipulate an order for the receivers to respond, thus solving the feedback collision problem; （2） it extends the usage of busy tone for preventing data frame collisions into the multicast scenario; and （3） it introduces a new usage of busy tone for acknowledging data frames positively. In addition, RMAC is generalized into a comprehensive MAC protocol that provides both reliable and unreliable services for all the three modes of communications： unicast, multicast, and broadcast, making it capable of supporting various upper-layer protocols. The evaluation shows that RMAC achieves high reliability with very limited overhead. RMAC is also compared with other reliable MAC protocols, showing that RMAC not only provides higher reliability but also involves lower cost.

p-RWBO:a novel low-collision and QoS-supported MAC for wireless ad hoc networks

QoS supported MAC mechanism is a key issue for supporting QoS in wireless ad hoc networks. A new backoff algorithm, named RWBO＋BEB, was proposed previ- ously to decrease the packet collision probability significantly. In this paper, it is explored how to make RWBO＋BEB support service differentiation in wireless ad hoc networks, and a novel proportional service differentiation algorithm, named p-RWBO, is proposed to allocate the wireless bandwidth according to the band- width ratio of each station. In p-RWBO, station n＇s walking probability （Pw,n） is selected according to its allocated bandwidth ratio. An analytical model is proposed to analyze how to choose Pw, n according to the bandwidth ratios of station n. The simulation results indicate that p-RWBO can differentiate services in terms of both bandwidth and delay.

Improved Algorithm for Broadcast Scheduling of Minimal Latency in Wireless Ad Hoc Networks

A wide range of applications for wireless ad hoc networks are time-critical and impose stringent requirement on the communication latency. One of the key communication operations is to broadcast a message from a source node. This paper studies the minimum latency broadcast scheduling problem in wireless ad hoc networks under collision-free transmission model. The previously best known algorithm for this NP-hard problem produces a broadcast schedule whose latency is at least 648（rmax/rmin）^2 times that of the optimal schedule, where rmax and rmin are the maximum and minimum transmission ranges of nodes in a network, respectively. We significantly improve this result by proposing a new scheduling algorithm whose approximation performance ratio is at most （1 ＋ 2rmax/rmin）^2＋32, Moreover, under the proposed scheduling each node just needs to forward a message at most once.

Remote monitoring system for livestock environmental information based on LoRa wireless ad hoc network technology

The environmental quality of livestock houses is key to livestock breeding and directly affects the growth and health of animals.To target the characteristics of long application cycles and large coverage areas for environmental monitoring in large-scale livestock breeding,the current study designed a remote monitoring system to provide livestock environmental information based on LoRa wireless ad hoc network technology.The system consisted of collection terminals,control terminals,LoRa gateways,and Alibaba Elastic Compute Service.It realized real-time collection,wireless transmission,storage of multi-sensor node data,and remote control.The system was not limited by the selected time or region,because data interaction was achieved by accessing cloud servers using GPRS technology.Users could browse and obtain data from computers and a WeChat mini program from any location with network coverage.Additionally,the system used the improved receiver-based auto rate(RBAR)rate-adaptive algorithm in the LoRa wireless communication component.After application on a dairy farm,the results showed that the whole system collected 6140 sets of environmental data from four dairy houses.The packet loss rate was less than 1%within a communication distance of 604 m,and the communication success rate was greater than 99%.The control instructions were real-time and accurate,and the response time was less than 10 s,which met the remote control needs of large farms.The system provided powerful data and technical support for precision animal production.

A topology control algorithm for preserving minimum-energy paths in wireless ad hoc networks

In this paper,a distributed topology control algorithm is proposed.By adjusting the transmission power of each node,this algorithm constructs a wireless network topology with minimum-energy property,i.e.,it preserves a minimum-energy path between every pair of nodes.More-over,the proposed algorithm can be used in both homogenous and heterogeneous wireless networks,and it can also work without an explicit propagation channel model or the position information of nodes.Simulation results show that the proposed algorithm has advantages over the topology control algorithm based on direct-transmission region in terms of average node degree and power efficiency.

A load-balanced minimum energy routing algorithm for Wireless Ad Hoc Sensor Networks

Wireless Ad Hoc Sensor Networks (WSNs) have received considerable academia research attention at present. The energy-constraint sensor nodes in WSNs operate on limited batteries, so it is a very important issue to use energy efficiently and reduce power consumption. To maximize the network lifetime, it is essential to prolong each individual node’s lifetime through minimizing the transmission energy consumption, so that many minimum energy routing schemes for traditional mobile ad hoc network have been developed for this reason. This paper presents a novel minimum energy routing algorithm named Load-Balanced Minimum Energy Routing (LBMER) for WSNs considering both sensor nodes’ energy consumption status and the sensor nodes’ hierarchical congestion levels, which uses mixture of energy balance and traffic balance to solve the problem of “hot spots” of WSNs and avoid the situation of “hot spots” sensor nodes using their energy at much higher rate and die much faster than the other nodes. The path router established by LBMER will not be very congested and the traffic will be distributed evenly in the WSNs. Simulation results verified that the LBMER performance is better than that of Min-Hop routing and the existing minimum energy routing scheme MTPR (Total Transmission Power Routing).

A Preamble-Based Broadcasting Technique for Wireless Ad Hoc Sensor Networks

Broadcasting is a fundamental operation in any wireless networks, more so in wireless ad hoc sensor networks, where each sensor node has limited transmission range as well as battery power. Although broadcasting in wireless ad hoc sensor networks has many advantages but it can cause serious problems like-broadcast storm, which could cause a lot of contention, redundant retransmission, collision and most importantly, drain immense amount of energy from limited battery powered sensor nodes. In this work, our objective is to reduce the number of retransmission and energy consumption of sensor nodes by using the duty cycle property of wireless ad hoc sensor networks. We propose a preamble-based broadcasting technique for wireless ad hoc sensor networks. We show that in dense wireless ad hoc sensor networks a small size preamble can give maximum network-wide data dissemination rather than using the large preamble, which will only consume immense amount of energy during packet reception.

Fair rate control for wireless ad-hoc networks with time varying channel capacities

We consider the problem of fair rate control for wireless ad-hoc networks with time varying channel capacities. The interaction between links in wireless ad-hoc networks introduces additional constraints on the flow rate. A primal-dual algorithm that guarantees fair rate control is proved to be trajectory stable. Various fairness indexes are obtained by choosing the specified form of the utility functions, and the numerical results validate the effectiveness of the proposed algorithm.

ON THE CAPACITY REGION OF WIRELESS AD HOC RELAY NETWORKS

Network capacity is a key characteristic to evaluate the performance of wireless networks. The goal of this paper is to study the capacity of wireless ad hoc relay network. In the model, there is at most ns source nodes transmitting signal simultaneously in the network and the arbitrarily complex network coding is allowed. The upper capacity bound of the network model are derived from the max-flow min-cut theorem and the lower capacity bound are obtained by the rate-distortion function for the Gaussian source. Finally, simula-tion results show that the upper network capacity will decrease as the number of source nodes is increased.

Joint routing and rate allocation for multiple video streams in ad-hoc wireless networks

The support for multiple video streams in an ad-hoc wireless network requires appropriate routing and rate allocation measures ascertaining the set of links for transmitting each stream and the encoding rate of the video to be delivered over the chosen links. The routing and rate allocation procedures impact the sustained quality of each video stream measured as the mean squared error (MSE) distortion at the receiver, and the overall network congestion in terms of queuing delay per link. We study the trade-off between these two competing objectives in a convex optimization formulation, and discuss both centralized and dis- tributed solutions for joint routing and rate allocation for multiple streams. For each stream, the optimal allocated rate strikes a balance between the selfish motive of minimizing video distortion and the global good of minimizing network congestions, while the routes are chosen over the least-congested links in the network. In addition to detailed analysis, network simulation results using ns-2 are presented for studying the optimal choice of parameters and to confirm the effectiveness of the proposed measures.

基于信号方差的Ad-Hoc网络路由算法

为解决Ad-Hoc路由协议查找路径过程中,由于从源节点到目的节点的传输路径会因为某个节点移动而导致整条路径中断,造成最短路径通常不是最稳定路径问题,提出一个以信号方差为基础的路由选择方法。通过侦测到的节点间信号强度,观察其信号变动程度,当信号变动值很小时,表示该节点间的链接处于稳定的状态,较不易断线。这些稳定链接组成的路径将是一条最稳定的路径。通过实验仿真验证,利用该方法所选路由,路径的稳定度明显优于其它算法。