An optimised resource aware approach to information collection in ad hoc networks

In ad hoc networks there is a need for all-to-one protocols that allow for information collection or “sensing” of the state of an ad hoc network and the nodes that comprise it. Such protocols may be used for service discovery, auto-configuration, network management, topology discovery or reliable flooding. There is a parallel between this type of sensing in ad hoc networks and that of sensor networks. However, ad hoc networks and sensor networks differ in their application, construction, characteristics and constraints. The main priority of sensor networks is for the flow of data from sensors back to a sink, but in an ad hoc network this may be of secondary importance. Hence, protocols suitable to sensor networks are not necessarily suitable to ad hoc networks and vice versa. We propose, Resource Aware Information Collection (RAIC), a distributed two phased resource aware approach to information collection in ad hoc networks. RAIC utilises a resource aware optimised flooding mechanism to both disseminate requests and initialise a backbone of resource suitable nodes responsible for relaying replies back to the node collecting information. RAIC in the process of collecting information from all nodes in an ad hoc network is shown to consume less energy and introduce less overhead compared with Directed Diffusion and a brute force approach. Importantly, over multiple successive queries (in an energy constrained environment), the use of resource awareness allows for the load of relaying to be distributed to those nodes most suitable, thereby extending the lifetime of the network.     

Increased network routing efficiency through coordinated Fibbing

For finding the best route in a network, distributed routing offers robustness but has poor flexibility while central control of software‐defined networking is just the opposite. The Fibbing architecture can run distributed routing protocols on software‐defined networking and has both robustness and flexibility. The 2 main steps of Fibbing's process are (1) compute a route that is available for the network according to the network topology and the flow request and (2) add fake nodes and fake links to augment the network topology in conformity with the distributed routing protocol and the route computed in the first step. Both of the 2 steps affect the performance of the network, but Fibbing does not consider them coordinately, and the cost of choosing the routes can be reduced further. In this paper, a coordinated algorithm for Fibbing is proposed to determine a lowest‐cost route. In the process to calculate an available route, our algorithm accommodates not only the network topology and the flow request but also the fake nodes and the fake links. The experiments on random topologies and classic topologies show that our algorithm can reduce the numbers of the fake nodes and the costs of the chosen routes, with the improved flow request acceptance ratios achieved.     

Routing in mobile wireless sensor network: a survey

The Mobile Wireless Sensor Network (MWSN) is an emerging technology with significant applications. The MWSN allows the sensor nodes to move freely and they are able to communicate with each other without the need for a fixed infrastructure. These networks are capable of out-performing static wireless sensor networks as they tend to increase the network lifetime, reduce the power consumption, provide more channel capacity and perform better targeting. Usually routing process in a mobile network is very complex and it becomes even more complicated in MWSN as the sensor nodes are low power, cost effective mobile devices with minimum resources. Recent research works have led to the design of many efficient routing protocols for MWSN but still there are many unresolved problems like retaining the network connectivity, reducing the energy cost, maintaining adequate sensing coverage etc. This paper addresses the various issues in routing and presents the state of the art routing protocols in MWSN. The routing protocols are categorized based on their network structure, state of information, energy efficiency and mobility. The classification presented here summarizes the main features of many published proposals in the literature for efficient routing in MWSN and also gives an insight into the enhancements that can be done to improve the existing routing protocols.     

Mobility control and its applications in mobile ad hoc networks

Most existing localized protocols in mobile ad hoc networks, such as data communication and topology control, use local information for decentralized decision among nodes to achieve certain global objectives. These objectives include determining a small connected dominating set for virtual backbone and topology control by adjusting transmission ranges of nodes. Because of asynchronous sampling of local information at each node, delays at different stages of protocol handshake, and movement of mobile nodes, the local view captured at different nodes many be inconsistent and/or outdated and many not reflect the actual network situation. The former may cause "bad" decisions that fail to keep the given global constraint such as global domination and connectivity, and the latter may incur "broken" links, which in turn would ultimately cause the failure of the constraint. In this article we review some techniques that handle inconsistent and outdated local views. These techniques are illustrated using several well-known protocols in data communication and topology control.     

Security based on network topology against the wiretapping attack

In wireless networks, an attacker can tune a receiver and tap the communication between two nodes. Whether or not some meaningful information is obtained by tapping a wireless connection depends the security protocols used. One may use cryptographic techniques to secure the communications. In this article we discuss an alternate way of securing the communication between two nodes. We provide a simple security protocol against a wiretapping attack based on the network topology. Although we study the problem from a theoretical perspective, our protocol is easily implementable. Our protocol is at least as secure as any other protocol against these attacks. We show that an attacker can get any meaningful information only by wiretapping those links that are necessary for the communication between the sender and the receiver. We use techniques from network encoding. Our protocol works for any network topology, including cycle networks. We note here that acyclicity is the main assumption in much of the network encoding literature.     

无线传感器网络拓扑结构研究

随着处理技术、存储技术以及无线传输技术的不断发展,由体积小、重量轻、价格低的无线传感器节点所组成的传感器网络已经充分具备了感知客观事物及自然现象,随时随地为用户提供精确信息的能力。通过对于星状网、网状网和混合网等几种常用传感器网络拓扑结构的比较,以及针对这些拓扑结构所形成的网络寿命的仿真,说明了对于常用的基站距离远、节点密度大的传感器网络,分层式的拓扑结构能够大大的节省网络能量,延长网络寿命,改善网络性能。     

Distributed fault-tolerant topology control in wireless multi-hop networks

In wireless multi-hop and ad-hoc networks, minimizing power consumption and at the same time maintaining desired properties of the network topology is of prime importance. In this work, we present a distributed algorithm for assigning minimum possible power to all the nodes in a static wireless network such that the resultant network topology is k-connected. In this algorithm, a node collects the location and maximum power information from all nodes in its vicinity, and then adjusts the power of these nodes in such a way that it can reach all of them through k optimal vertex-disjoint paths. The algorithm ensures k-connectivity in the final topology provided the topology induced when all nodes transmit with their maximum power is k-connected. We extend our topology control algorithm from static networks to networks having mobile nodes. We present proof of correctness for our algorithm for both static and mobile scenarios, and through extensive simulation we present its behavior.     

WRE‐OLSR,a new scheme for enhancing the lifetime within ad hoc and wireless sensor networks

Within ad hoc and wireless sensor networks, communications are accomplished in dynamic environments with a random movement of mobile devices. Thus, routing protocols over these networks are an important concern to offer efficient network scalability, manage topology information, and prolong the network lifetime. Optimized link state routing (OLSR) is one of those routing protocols implemented in ad hoc and wireless sensor networks. Because of its proactive technique, routes between two nodes are established in a very short time, but it can spend a lot of resources for selecting the multipoint relays (MPRs: nodes responsible for routing data) and exchanging topology control information. Thus, nodes playing for a long time a role of MPR within networks implementing such protocol can rapidly exhaust their batteries, which create route failures and affect the network lifetime. Our main approach relies on analyzing this concern by introducing a new criterion that implements a combination between the residual energy of a node and its reachability in order to determine the optimal number of MPRs and sustain the network lifetime. Simulations performed illustrate obviously that our approach is more significant compared with the basic heuristic used by original OLSR to compute the MPR set of a node.     

A graphical methodology for simulating communication networks

A novel approach for simulating communication networks is discussed and illustrated with two examples of a token-passing network. The method is based on a graphical representation of the network consisting of three components: topology, nodes, and protocols. The topology and nodes are drawn to a network specification. The protocols are drawn by using Petri nets with some extended features. A simulation model can be automatically generated from this representation. Results of the simulation are compared to those of an analytical model, showing excellent agreement     

A peer-to-peer zone-based two-level link state routing for mobilead hoc networks

A new global positioning system (GPS)-based routing protocol for ad hoc networks, called zone-based hierarchical link state (ZHLS) routing protocol, is proposed. In this protocol, the network is divided into nonoverlapping zones. Each node only knows the node connectivity within its zone and the zone connectivity of the whole network. The link state routing is performed on two levels: focal node and global zone levels. Unlike other hierarchical protocols, there is no cluster head in this protocol. The zone level topological information is distributed to all nodes. This “peer-to-peer” manner mitigates traffic bottleneck, avoids single point of failure, and simplifies mobility management. Since only zone ID and node ID of a destination are needed for routing, the route from a source to a destination is adaptable to changing topology. The zone ID of the destination is found by sending one location request to every zone. Simulation results show that our location search scheme generates less overhead than the schemes based on flooding. The results also confirm that the communication overhead for creating and maintaining the topology in the proposed protocol is smaller than that in the flat LSR protocol. This new routing protocol provides a flexible, efficient, and effective approach to accommodate the changing topology in a wireless network environment     

A location-based routing method for mobile ad hoc networks

Using location information to help routing is often proposed as a means to achieve scalability in large mobile ad hoc networks. However, location-based routing is difficult when there are holes in the network topology and nodes are mobile or frequently disconnected to save battery. Terminode routing, presented here, addresses these issues. It uses a combination of location-based routing (terminode remote routing, TRR), used when the destination is far, and link state-routing (terminode local routing, TLR), used when the destination is close. TRR uses anchored paths, a list of geographic points (not nodes) used as loose source routing information. Anchored paths are discovered and managed by sources, using one of two low overhead protocols: friend assisted path discovery and geographical map-based path discovery. Our simulation results show that terminode routing performs well in networks of various sizes. In smaller networks; the performance is comparable to MANET routing protocols. In larger networks that are not uniformly populated with nodes, terminode routing outperforms, existing location-based or MANET routing protocols.     

Biologically inspired artificial intrusion detection system for detecting wormhole attack in MANET

A mobile ad hoc network (MANET) does not have traffic concentration points such as gateway or access points which perform behaviour monitoring of individual nodes. Therefore, maintaining the network function for the normal nodes when other nodes do not forward and route properly is a big challenge. One of the significant attacks in ad hoc network is wormhole attack. In this wormhole attack, the adversary disrupts ad hoc routing protocols using higher bandwidth and lower-latency links. Wormhole attack is more hidden in character and tougher to detect. So, it is necessary to use mechanisms to avoid attacking nodes which can disclose communication among unauthorized nodes in ad hoc networks. Mechanisms to detect and punish such attacking nodes are the only solution to solve this problem. Those mechanisms are known as intrusion detection systems (IDS). In this paper, the suggested biological based artificial intrusion detection system (BAIDS) include hybrid negative selection algorithm (HNSA) detectors in the local and broad detection subsection to detect anomalies in ad hoc network. In addition to that, response will be issued to take action over the misbehaving nodes. These detectors employed in BAIDS are capable of discriminating well behaving nodes from attacking nodes with a good level of accuracy in a MANET environment. The performance of BAIDS in detecting wormhole attacks in the background of DSR, AODV and DSDV routing protocols is also evaluated using Qualnet v 5.2 network simulator. Detection rate, false alarm rate, packet delivery ratio, routing overhead are used as metrics to compare the performance of HNSA and the BAIDS technique.     

Topology and mobility considerations in mobile ad hoc networks

A highly dynamic topology is a distinguishing feature and challenge of a mobile ad hoc network. Links between nodes are created and broken, as the nodes move within the network. This node mobility affects not only the source and/or destination, as in a conventional wireless network, but also intermediate nodes, due to the network’s multihop nature. The resulting routes can be extremely volatile, making successful ad hoc routing dependent on efficiently reacting to these topology changes.

In order to better understand this environment, a number of characteristics have been studied concerning the links and routes that make up an ad hoc network. Several network parameters are examined, including number of nodes, network dimensions, and radio transmission range, as well as mobility parameters for maximum speed and wait times. In addition to suggesting guidelines for the evaluation of ad hoc networks, the results reveal several properties that should be considered in the design and optimization of MANET protocols.     

Mobile backbone synthesis for ad hoc wireless networks

In this paper, we present an extended mobile backbone network topology synthesis algorithm (ETSA) for constructing and maintaining a dynamic backbone structure for mobile ad hoc wireless networks. We present and analyze the mathematical features of the proposed scheme. Using these results, we prove that: (1) The ETSA scheme converges in constant time; (2) The length of each control packet is bounded by a constant value that is independent of the number of network nodes; (3) The size of the backbone network depends only on the size of the operational area and is independent of nodal density. We compare the performance features of this scheme with those characterizing other protocols that employ clustering operations and/or use selective forwarding on demand routing methods. In addition, we present an on-demand routing protocol (MBNR) that makes use of the underlying dynamically self-configuring backbone network infrastructure and demonstrate its performance advantages when compared with an on-demand routing protocol that is based on a flat architecture, as well as with other backbone-based routing protocols.     

Cross-layer activity management in an 802-15.4 sensor network

Sensor networks operate under conflicting requirements of maintaining the desired value of information throughput while simultaneously maximizing the lifetime of individual nodes. In doing so, the characteristics of the operating environment, including the MAC and PHY layers, have to be taken into account as well. In this article we consider activity management of sensor nodes in a beacon-enabled IEEE 802.15.4-compliant network. Activity management is performed through lightweight probabilistic control of the duration of sleep and service periods of individual sensors. We present two distributed activity management policies which are capable of achieving and maintaining the desired network reliability while maximizing the lifetime of the entire network.     

An EDRI-based approach for detecting and eliminating cooperative black hole nodes in MANET

Mobile Ad hoc Network (MANET) is a self-configurable, self-maintenance network with wireless, mobile nodes. Special features of MANET like dynamic topology, hop-by-hop communications and open network boundary, made security highly challengeable in this network. From security aspect, routing protocols are highly vulnerable against a wide range of attacks like black hole. In black hole attack malicious node injects fault routing information to the network and leads all data packets toward it-self. In this paper, we proposed an approach to detect and eliminate cooperative malicious nodes in MANET with AODV routing protocol. A data control packet is used in order to check the nodes in selected path; also, by using an Extended Data Routing Information table, all malicious nodes in selected path are detected, then, eliminated from network. For evaluation, our approach and a previous work have been implemented using Opnet 14 in different scenarios. Referring to simulation results, the proposed approach decreases packet overhead and delay of security mechanism with no false positive detection. In addition, network throughput is improved by using the proposed approach.     

Determining the optimal configuration for the zone routing protocol

The zone routing protocol (ZRP) is a hybrid routing protocol that proactively maintains routes within a local region of the network (which we refer to as the routing zone). Knowledge of this routing zone topology is leveraged by the ZRP to improve the efficiency of a reactive route query/reply mechanism. The ZRP can be configured for a particular network through adjustment of a single parameter, the routing zone radius. We address the issue of configuring the ZRP to provide the best performance for a particular network at any time. Previous work has demonstrated that an optimally configured ZRP operates at least as efficiently as traditional reactive flood-search or proactive distance vector/link state routing protocols (and in many cases, much more efficiently). Adaptation of the ZIP to changing network conditions requires both an understanding of how the ZRP reacts to changes in network behavior and a mechanism to allow individual nodes to identify these changes given only limited knowledge of the network behavior. We demonstrate the effects of relative node velocity, node density, network span, and user data activity on the performance of the ZRP. We then introduce two different schemes (“min searching” and “traffic adaptive”) that allow individual nodes to identify and appropriately react to changes in network configuration, based only on information derived from the amount of received ZRP traffic. Through test-bed simulation, we demonstrate that these radius estimation techniques can allow the ZRP to operate within 2% of the control traffic resulting from perfect radius estimation     

天基信息网络的软件定义网络应用探析

现有各种空间、地面网络节点的互连互通,在一定程度上可满足特定应用需求,但由于各节点在空间、物理以及功能的局限,限制了天基信息高效传输、融合以及按需地应用。分析了天基信息网络的发展趋势,提出了网络架构构想,并对主要关键技术的研究方向进行了梳理。在空间核心节点上采用软件定义的多功能载荷平台,并基于软件定义网络( SDN)架构和空间容中断网络协议构建天基信息网络。通过资源虚拟化、处理多元化、应用无阻化的方式,保障天基信息网络适应信息按需定制和高效共享等应用需求。     

A Safe Proactive Routing Protocol SDSDV for Ad Hoc Network

In mobile Ad Hoc network, nodes move freely, this can lead to frequent changes of network topology. Routing protocol algorithm is the strategy to establish communication links for network nodes, and its performance influences the availability of Ad Hoc network directly. By using wireless channel to transmit data in Ad Hoc network, the invaded malicious nodes will cause various attacks, aim to steal the transmission data or destroy the network. Based on the traditional proactive routing protocol for Ad Hoc network, an improved safe routing strategy SDSDV is put forward to resist attacks against routing protocols. The safe proactive routing protocol includes route request and route response two stages. When the network initialization is complete, after successful identity authentication by each other, secure communication paths are established between nodes and the encrypted data will be transmission through the path. The protocol integrates distributed authentication, encryption algorithm, hash check, and other security policy together. SDSDV protocol reduces the risk of malicious manipulation of routing information and ensures the safe and reliable routing between the source and destination nodes.     

Service Locating for Large-Scale Mobile Ad-Hoc Network

In a mobile ad-hoc network, an efficient service discovery system is needed to locate various service providers. However, because an ad-hoc network has no fixed topology, its service locating is quite different from traditional schemes for the Internet. In this article, we present a novel service locating system specifically designed for large-scale mobile ad-hoc networks. In our system, a subset of nodes is dynamically elected and self-organized into a virtual backbone (VB). These VB nodes manage the directory information of services and monitor path quality of service on behalf of end users. Such information is then used to direct the selection of appropriate providers. We evaluate the performance of our system through simulation. The result demonstrates that the proposed locating system greatly improves the quality of service delivery while maintaining reasonably low cost.