Lifetime optimization for reliable broadcast and multicast in wireless ad hoc networks

In this paper, we consider the reliable broadcast and multicast lifetime maximization problems in energy‐constrained wireless ad hoc networks, such as wireless sensor networks for environment monitoring and wireless ad hoc networks consisting of laptops or PDAs with limited battery capacities. In packet loss‐free networks, the optimal solution of lifetime maximization problem can be easily obtained by tree‐based algorithms. In unreliable networks, we formulate them as min–max tree problems and prove them NP‐complete by a reduction from a well‐known minimum degree spanning tree problem. A link quality‐aware heuristic algorithm called Maximum Lifetime Reliable Broadcast Tree (MLRBT) is proposed to build a broadcast tree that maximizes the network lifetime. The reliable multicast lifetime maximization problem can be solved as well by pruning the broadcast tree produced by the MLRBT algorithm. The time complexity analysis of both algorithms is also provided. Simulation results show that the proposed algorithms can significantly increase the network lifetime compared with the traditional algorithms under various distributions of error probability on lossy wireless links. Copyright © 2012 John Wiley & Sons, Ltd.     

On the construction of maximum residual energy resource broadcast trees with minimum diameter in static ad hoc wireless networks

Each node in a wireless ad hoc network runs on a local energy source that has a limited energy life span. Thus, energy conservation is a critical issue in such networks. In addition, it is in general desirable to construct routes with low hop counts as a route with a high hop count is more likely to be unstable (because the probability that intermediate nodes will move away is higher). In this paper, we address these two issues concurrently with energy conservation as the primary objective and low hop count as the secondary objective. One way of addressing the energy conservation issue is to construct routes that maximize the minimum residual battery capacity available among all nodes in each route. A broadcast tree with all routes satisfying this condition is referred to as a maximum residual energy resource broadcast tree. A maximum residual energy resource broadcast tree with the least diameter is referred to as a minimum diameter maximum residual energy resource broadcast tree and the problem of constructing such a tree is referred to as the minimum diameter maximum residual energy resource broadcast routing problem (MDMRERBRP). We propose an algorithm for MDMRERBRP and prove that MDMRERBRP is optimally solvable in polynomial time using the proposed algorithm. Copyright © 2005 John Wiley & Sons, Ltd.     

An energy‐efficient localized topology control algorithm for wireless ad hoc and sensor networks

Topology control plays an important role in the design of wireless ad hoc and sensor networks and has demonstrated its high capability in constructing networks with desirable characteristics such as sparser connectivity, lower transmission power, and smaller node degree. However, the enforcement of a topology control algorithm in a network may degrade the energy‐draining balancing capability of the network and thus reduce the network operational lifetime. For this reason, it is important to take into account energy efficiency in the design of a topology control algorithm in order to achieve prolonged network lifetime. In this paper, we propose a localized energy‐efficient topology control algorithm for wireless ad hoc and sensor networks with power control capability in network nodes. To achieve prolonged network lifetime, we introduce a concept called energy criticality avoidance and propose an energy criticality avoidance strategy in topology control and energy‐efficient routing. Through theoretical analysis and simulation results, we prove that the proposed topology control algorithm can maintain the global network connectivity with low complexity and can significantly prolong the lifetime of a multi‐hop wireless network as compared with existing topology control algorithms with little additional protocol overhead. Copyright © 2008 John Wiley & Sons, Ltd.     

Deploying power‐aware on‐demand (PAOD) schemes over routing protocols of mobile wireless ad hoc networks

A mobile ad hoc network (MANET) is an autonomous collection of mobile nodes that communicate over relatively bandwidth‐constrained wireless links. MANETs need efficient algorithms to determine network connectivity, link scheduling, and routing. An important issue in network routing for MANETs is to conserve power while still achieve a high packet success rate. Traditional MANET routing protocols do not count for such concern. They all assume working with unlimited power reservoirs. Several ideas have been proposed for adding power‐awareness capabilities to ad hoc networks. Most of these proposals tackle the issue by either proposing new power‐aware routing protocols or modifying existing routing protocols through the deployment of power information as cost functions. None of them deal with counter‐measures that ought to be taken when nodes suffer from low power reserves and are subject to shut down in mid of normal network operations. In this paper, power‐awareness is added to a well‐known traditional routing protocol, the ad hoc on‐demand distance vector (AODV) routing protocol. The original algorithm is modified to deal with situations in which nodes experience low power reserves. Two schemes are proposed and compared with the original protocol using different performance metrics such as average end‐to‐end delays, transmission success rates, and throughputs. These schemes provide capabilities for AODV to deal with situations in which operating nodes have almost consumed their power reserves. Copyright © 2005 John Wiley & Sons, Ltd.     

Virtual base stations for wireless mobile ad hoc communications: an infrastructure for the infrastructure‐less

In this paper, we propose a new protocol for wireless mobile ad hoc networks, which establishes a dynamic wireless mobile infrastructure. The proposed protocol, namely, the virtual base stations (VBS) protocol, mimics and maintains the operation of the conventional fixed infrastructure in cellular networks. In the VBS protocol, a mobile node is elected from a set of nominees to act as a temporary base station within its zone. We provide proofs for the correctness of the VBS protocol, and show lower and upper bounds for its global convergence time. Likewise, we study the characteristics and performance of VBS by means of simulation. It is shown that VBS scales well to large networks of mobile stations, and that it outperforms other infrastructure‐formation protocols in terms of stability. The VBS protocol would facilitate the development of a comprehensive and promising framework for quality of service (QoS) management in wireless mobile ad hoc networks once the proper integration of the MAC protocol with the routing and call admission control mechanisms is established. The VBS architecture lays the groundwork for assigning bandwidth, and/or implementing priorities, and hence for QoS‐based routing by conveying the quality of a path prior to call setup. Copyright © 2001 John Wiley & Sons, Ltd.     

A survey of current architectures for connecting wireless mobile ad hoc networks to the Internet

Connecting wired and wireless networks, and particularly mobile wireless ad hoc networks (MANETs) and the global Internet, is attractive in real‐world scenarios due to its usefulness and praticality. Because of the various architectural mismatches between the Internet and MANETs with regard to their communication topology, routing protocols, and operation, it is necessary to introduce a hybrid interface capable of connecting to the Internet using Mobile IP protocol and to MANETs owing to an ad hoc routing protocol. Specifically, the approaches available in the literature have introduced updated versions of Mobile IP agents or access points at the edge of the Internet to help MANET nodes get multi‐hop wireless Internet access. The main differences in the existing approaches concern the type of ad hoc routing protocol as well as the switching algorithm used by MANET nodes to change their current Mobile IP agents based on specific switching criteria. This paper surveys a variety of approaches to providing multi‐hop wireless Internet access to MANET nodes. Copyright © 2006 John Wiley & Sons, Ltd.     

Ad hoc mobile multicast routing using the concept of long‐lived routes

Mobile ad hoc networks are recognized by their abilities to form, sustain, and deform networks on‐the‐fly without the need for any pre‐established and fixed infrastructures. This wireless multi‐hop technology requires adaptive networking protocols with low control overhead and low power consumption to operate efficiently. Existing research so far are mainly concerned with unicast routing for ad hoc mobile networks. There is a growing interest in supporting multicast communication in an ad hoc mobile environment. In this paper, the associativity‐based ad hoc multicast (ABAM) routing protocol is proposed. The concept of association stability is utilized during multicast tree discovery, selection, and reconfiguration. This allows routes that are long‐lived to be selected, thereby reducing the frequency of route reconstructions. ABAM employs a localized route reconstruction strategy in response to migrations by source, receiver, and tree nodes. It can repair an affected subtree via a single route reconstruction operation. ABAM is robust since the repair can be triggered by a node in the tree or by the migrated node itself. ABAM is also capable of handling multicast group dynamics when mobile hosts decide to join and leave an existing multicast group. Our simulation results reveal that under different mobility scenarios and multicast group size, ABAM has low communication overhead and yields better throughput performance. Copyright © 2001 John Wiley & Sons, Ltd.     

Cross‐layer design for topology control and routing in MANETs

A mobile ad hoc network (MANET) is a self‐organized and adaptive wireless network formed by dynamically gathering mobile nodes. Since the topology of the network is constantly changing, the issue of routing packets and energy conservation become challenging tasks. In this paper, we propose a cross‐layer design that jointly considers routing and topology control taking mobility and interference into account for MANETs. We called the proposed protocol as Mobility‐aware Routing and Interference‐aware Topology control (MRIT) protocol. The main objective of the proposed protocol is to increase the network lifetime, reduce energy consumption, and find stable end‐to‐end routes for MANETs. We evaluate the performance of the proposed protocol by comprehensively simulating a set of random MANET environments. The results show that the proposed protocol reduces energy consumption rate, end‐to‐end delay, interference while preserving throughput and network connectivity. Copyright © 2010 John Wiley & Sons, Ltd.     

HSG‐ad hoc network: A novel hierarchical star graph ad hoc network with self‐organization and routing discovery free

In ad hoc wireless networks, most data are delivered by multi‐hop routing (hop by hop). This approach may cause long delay and a high routing overhead regardless of which routing protocol is used. To mitigate this inherent characteristic, this work presents a novel ad hoc network structure that adopts dual‐card‐mode, self‐organization with specific IP naming and channel assignment to form a hierarchical star graph ad hoc network (HSG‐ad hoc). This network not only expedites data transmission but also eliminates the route discovery procedure during data transmission. Therefore, the overall network reliability and stability are significantly improved. Simulation results show that the proposed approach achieves substantial improvements over DSDV, AODV, and DSR in terms of average end‐to‐end delay, throughput, and packet delivery ratio. Copyright © 2009 John Wiley & Sons, Ltd.     

QoS‐aware routing and power control algorithm for multimedia service over multi‐hop mobile ad hoc network

This paper presents a QoS (quality of service) aware routing and power control algorithm consuming low transmission power for multimedia service over mobile ad hoc network. Generally, multimedia services need stringent QoS over the network. However, it is not easy to guarantee the QoS over mobile ad hoc network since its network resources are very limited and time‐varying. Furthermore, only a limited amount of power is available at mobile nodes, which makes the problem more challenging. We propose an effective routing and power control algorithm for multimedia services that satisfies end‐to‐end delay constraint with low transmission power consumption. The proposed algorithm supports the required bandwidth by controlling each link channel quality over route in a tolerable range. In addition, a simple but effective route maintenance mechanism is implemented to avoid link failures that may significantly degrade streaming video quality. Finally, performance comparison with existing algorithms is presented in respect to traditional routing performance metrics, and an achievable video quality comparison is provided to demonstrate the superiority of the proposed algorithm for multimedia services over mobile ad hoc network. Copyright © 2010 John Wiley & Sons, Ltd.     

Multifold node authentication in mobile ad hoc networks

An ad hoc network is a collection of nodes that do not need to rely on a predefined infrastructure to keep the network connected. Nodes communicate amongst each other using wireless radios and operate by following a peer‐to‐peer network model. In this article, we propose a multifold node authentication approach for protecting mobile ad hoc networks. The security requirements for protecting data link and network layers are identified and the design criteria for creating secure ad hoc networks using multiple authentication protocols are analysed. Such protocols, which are based on zero‐knowledge and challenge‐response techniques, are presented through proofs and simulation results. Copyright © 2007 John Wiley & Sons, Ltd.     

Exploring the performance of TCP vegas in mobile ad hoc networks

Recent research efforts in mobile ad hoc networks have concentrated on examining the behaviour of TCP Reno over various ad hoc routing protocols and have suggested a number of extensions to improve its performance. TCP Vegas, which takes a proactive approach to congestion avoidance, has not so far been examined as a viable alternative to TCP Reno in wireless environments and no effort has been made to analyse its performance over routing protocols for MANETs. This paper evaluates using extensive simulation experiments the performance behaviour of TCP Vegas over a proactive (destination sequenced distance vector) and two reactive (dynamic source routing and ad hoc on demand distance vector) routing protocols and compares it against that of TCP Reno. Copyright © 2004 John Wiley & Sons, Ltd.     

On the characteristics of routing paths and the performance of routing protocols in vehicle‐formed mobile ad hoc networks on highways

Recently, intelligent transportation systems (ITS) is becoming an important research topic. One goal of ITS is to exchange information among vehicles in a timely and efficient manner. In the ITS research community, inter‐vehicle communications (IVC) is considered a way that may be able to achieve this goal. An information network built on the top of vehicles using IVC can be viewed as a type of mobile ad hoc networks (MANETs). In the past, several unicast routing protocols for MANET have been proposed. However, most of them are designed for general MANETs rather than for IVC networks. In this paper, we first used more realistic vehicle mobility traces generated by a microscopic traffic simulator (VISSIM) to understand the characteristics of routing paths in an IVC network. Based on the insights gained from the derived path characteristics, we designed and implemented an intelligent flooding‐based routing protocol for small‐scale IVC networks. Via several field trials conducted on highways, we compared the performance of ad hoc on‐demand distance vector (AODV) and our protocol. Our experimental results show that (1) our protocol outperforms AODV greatly in IVC networks and (2) our protocol can provide text, image, audio, and video services for small‐scale IVC networks (e.g., a platoon) quite well. Copyright © 2009 John Wiley & Sons, Ltd.     

Energy efficient routing protocols for mobile ad hoc networks

Although establishing correct and efficient routes is an important design issue in mobile ad hoc networks (MANETs), a more challenging goal is to provide energy efficient routes because mobile nodes' operation time is the most critical limiting factor. This article surveys and classifies the energy‐aware routing protocols proposed for MANETs. They minimize either the active communication energy required to transmit or receive packets or the inactive energy consumed when a mobile node stays idle but listens to the wireless medium for any possible communication requests from other nodes. Transmission power control approach and load distribution approach belong to the former category, and sleep/power‐down mode approach belongs to the latter category. While it is not clear whether any particular algorithm or a class of algorithms is the best for all scenarios, each protocol has definite advantages/disadvantages and is well suited for certain situations. The purpose of this paper is to facilitate the research efforts in combining the existing solutions to offer a more energy efficient routing mechanism. Copyright © 2003 John Wiley & Sons, Ltd.     

Routing in intermittent networks using storage domains

In this paper, we present a routing algorithm for a class of networks where a contemporaneous end‐to‐end path may not exist at the time of data transfer due to intermittent links. Several examples of such networks exist in the context of sensor networks, mobile ad hoc networks and delay tolerant networks. The proposed routing algorithms follow a priori routing similar to source routing. Link state changes are assumed to be known ahead of time, for instance, due to planned duty cycling resulting in scheduled connectivity. The basic idea behind the proposed routing algorithms is to modify the breadth first search (BFS) algorithm to take into account link state changes and find the quickest route between source and destination nodes. We introduce the idea of time‐varying storage domains where all nodes connected for a length of time act as a single storage unit by sharing the aggregated storage capacity of the nodes. This will help situations where storage is a limited resource. We evaluate the routing algorithm with and without storage domain in an extensive simulation. The delay performance of the proposed algorithms is conceptually the same as flooding‐based algorithms but without the penalty of multiple copies. More significantly, we show that the Quickest Storage Domain (Quickest SD) algorithm distributes the storage demand across many nodes in the network topology, enabling balanced load and higher network utilization. In fact, we show that for the same level of performance, we can actually cut the storage requirement in half using the Quickest SD algorithm. Copyright © 2009 John Wiley & Sons, Ltd.     

Power aware scalable multicast routing protocol for MANETs

Multicasting is an effective way to provide group communication. In mobile ad hoc networks (MANETs), multicasting can support a wide variety of applications that are characterized by a close degree of collaboration. Since MANETs exhibit severe resource constraints such as battery power, limited bandwidth, dynamic network topology and lack of centralized administration, multicasting in MANETs become complex. The existing multicast routing protocols concentrate more on quality of service parameters like end‐to‐end delay, jitter, bandwidth and power. They do not stress on the scalability factor of the multicast. In this paper, we address the problem of multicast scalability and propose an efficient scalable multicast routing protocol called ‘Power Aware Scalable Multicast Routing Protocol (PASMRP)’ for MANETs. PASMRP uses the concept of class of service with three priority levels and local re‐routing to provide scalability. The protocol also ensures fair utilization of the resources among the nodes through re‐routing and hence the lifetime of the network is increased. The protocol has been simulated and the results show that PASMRP has better scalability and enhanced lifetime than the existing multicast routing protocols. Copyright © 2005 John Wiley & Sons, Ltd.     

Ariadne: A Secure On-Demand Routing Protocol for Ad Hoc Networks

An ad hoc network is a group of wireless mobile computers (or nodes), in which individual nodes cooperate by forwarding packets for each other to allow nodes to communicate beyond direct wireless transmission range. Prior research in ad hoc networking has generally studied the routing problem in a non-adversarial setting, assuming a trusted environment. In this paper, we present attacks against routing in ad hoc networks, and we present the design and performance evaluation of a new secure on-demand ad hoc network routing protocol, called Ariadne. Ariadne prevents attackers or compromised nodes from tampering with uncompromised routes consisting of uncompromised nodes, and also prevents many types of Denial-of-Service attacks. In addition, Ariadne is efficient, using only highly efficient symmetric cryptographic primitives.     

Design and Realization of a Novel Header Compression Scheme for Ad Hoc Networks

IP header compression schemes offer a valuable measure for bandwidth preservation. Such schemes have been practically implemented in infrastructure‐based IP networks for point‐to‐point links. However, minimal research and practical implementation efforts have been conducted in the direction of an IP header compression strategy that can meet the peculiar requirements of multi‐hop ad hoc wireless networks. In this paper, we present a practically implemented multi‐hop IP header compression scheme using the Robust Header Compression (ROHC) protocol suite. The scheme runs on a novel identifier (ID) based networking architecture, known as an ID‐based ad hoc network (IDHOCNET). IDHOCNET additionally solves a number of bottlenecks of pure IP‐based ad hoc networks that have emerged owing to IP address auto‐configuration service, distributed naming and name resolution, and the role of an IP address as an identifier at the application layer. The proposed scheme was tested on a multi‐hop test bed. The results show that the implemented scheme has better gain and requires only O (1) ROHC contexts.     

A novel efficient power‐saving MAC protocol for multi‐hop MANETs

Following recent advances in the performance of ad hoc networks, the limited life of batteries in mobile devices poses a bottleneck in their development. Consequently, how to minimize power consumption in the Medium Access Control (MAC) layer of ad hoc networks is an essential issue. The power‐saving mode (PSM) of IEEE 802.11 involves the Timing Synchronization Function to reduce power consumption for single‐hop mobile ad hoc networks (MANETs). However, the IEEE 802.11 PSM is known to result in unnecessary energy consumption as well as the problems of overheating and back‐off time delay. Hence, this study presents an efficient power‐saving MAC protocol, called p‐MANET, based on a Multi‐hop Time Synchronization Protocol, which involves a hibernation mechanism, a beacon inhibition mechanism, and a low‐latency next‐hop selection mechanism for general‐purpose multi‐hop MANETs. The main purposes of the p‐MANET protocol are to reduce significantly the power consumption and the transmission latency. In the hibernation mechanism, each p‐MANET node needs only to wake up during one out of every N beacon interval, where N is the number of beacon intervals in a cycle. Thus, efficient power consumption is achieved. Furthermore, a beacon inhibition mechanism is proposed to prevent the beacon storm problem that is caused by synchronization and neighbor discovery messages. Finally, the low‐latency next‐hop selection mechanism is designed to yield low transmission latency. Each p‐MANET node is aware of the active beacon intervals of its neighbors by using a hash function, such that it can easily forward packets to a neighbor in active mode or with the least remaining time to wake up. As a consequence, upper‐layer routing protocols can cooperate with p‐MANET to select the next‐hop neighbor with the best forwarding delay. To verify the proposed design and demonstrate the favorable performance of the proposed p‐MANET, we present the theoretical analysis related to p‐MANET and also perform experimental simulations. The numerical results show that p‐MANET reduces power consumption and routing latency and performs well in extending lifetime with a small neighbor discovery time. Copyright © 2011 John Wiley & Sons, Ltd.     

QoS-aware minimum energy multicast tree construction in wireless ad hoc networks

Energy conservation is a critical issue in wireless ad hoc networks since batteries are the only limited-life energy source to power the nodes. One major metric for energy conservation is to route a communication session along the routes which require the lowest total energy consumption. Most recent algorithms for the MEM (Minimum Energy Multicast) problem considered energy efficiency as the ultimate objective in order to increase longevity of such networks. However, the introduction of real-time applications has posed additional challenges. Transmission of video and imaging data requires both energy and QoS-aware routing in order to ensure efficient usage of the networks. In this paper, we only consider “bandwidth” as the QoS in TDMA-based wireless ad hoc networks that use omni-directional antennas and have limited energy resources. We present a constraint formulation model for the QoS-MEM (QoS-aware Minimum Energy Multicast) problem in terms of mixed integer linear programming (MILP), which can be used for an optimal solution of the QoS-MEM problem. Experiment results show that in a typical static ad hoc network with 20 nodes, the optimal solutions can always be solved in a timely manner.