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Geographic greedy forwarding (GF) technique has been widely used by many algorithms for routing in sensor networks because of its high efficiency resulting from its local and memoryless nature. Hence, it ensures scalability which is a fundamental requirement for protocol applicability to large-scale sensor networks with limited resources. Nevertheless, GF suffers from a serious drawback when packets, based on geographic distance, cannot be delivered; i.e., the so-called “local minimum phenomenon”. This problem has been tackled in previous research works to guarantee packet delivery by routing around the boundaries of the hole, but at an excessive consumption of control overheads. In this paper, we propose a novel approach that exploits GF technique and guarantees at the same time packet delivery (handles the local minimum situations). Our approach is of a local nature that does not retain memories and performs better than the state-of-the-art approaches in terms of its ability to guarantee packet delivery and to derive efficient routing paths. We provide, in this paper, proof of its correctness (packet delivery guaranty) while showing, through simulations, its performance effectiveness in terms of reducing path lengths, average end-to-end delays, and overall energy consumption. [ABSTRACT FROM AUTHOR]

When evaluating the performance of routing protocols in wireless mesh network (WMN), we need deeper analysis from the aspect of network traffic complexity to show how traffic characteristics are influenced by routing protocols and node mobility. The predictability of network traffic can be used as one metric of complexity and can be analyzed by multi-scale entropy (MSE) method. With 20 different random waypoint (RWP) mobility scenarios and with destination sequenced distance vector (DSDV), a typical proactive protocol, and Ad hoc on-demand distance vector (AODV), a typical reactive protocol, the predictabilities of aggregated traffic of gateway in WMN are analyzed using MSE method to show how different routing protocols bear different mobility scenarios. The MSE results show that the aggregated traffic of gateway with DSDV is more difficult to be predicted than that with AODV for different mobility scenarios. The maxspeed parameter of RWP dominates the traffic predictability for AODV. Both of the pause time and the maxspeed parameters, have great influence on the traffic predictability for DSDV. The reasons lie in the behaviors of routing protocols, i.e., AODV has up-to-date paths while DSDV does not. [ABSTRACT FROM AUTHOR]

Providing better communication and maximising the communication performance in a Underwater Wireless Sensor Network (UWSN) is always challenging due to the volatile characteristics of the underwater environment. Radio signals cannot properly propagate underwater, so there is a need for acoustic technology that can support better data rates and reliable underwater wireless communications. Node mobility, 3-D spaces and horizontal communication links are some critical challenges to the researcher in designing new routing protocols for UWSNs. In this paper, we have proposed a novel routing protocol called Layer by layer Angle-Based Flooding (L2-ABF) to address the issues of continuous node movements, end-to-end delays and energy consumption. In L2-ABF, every node can calculate its flooding angle to forward data packets toward the sinks without using any explicit configuration or location information. The simulation results show that L2-ABF has some advantages over some existing flooding-based techniques and also can easily manage quick routing changes where node movements are frequent. [ABSTRACT FROM AUTHOR]

In this paper, the influence of the features of the propagation channel in the performance of Mobile Ad Hoc Networks (MANET) is studied. In order to overcome the possible propagation limitations, a particular reconfigurable multiantenna terminal configuration for MANETs is provided, along with an optimization procedure to select the proper radiation pattern at each node of the network. The adequate selection of the radiation pattern at each node lets maximize the transmission/reception capabilities of the wireless network, depending on the propagation channel features and their evolution in time. In addition, a modified routing strategy is proposed, based on the existence of an alternative route at each node, provided that the main one is not available because of propagation issues or incidences in the network. [ABSTRACT FROM AUTHOR]

In order to understand the message dissemination performance in delay-tolerant networks, much analysis work has been proposed in literature. However, existing work shares a common simplification that the pairwise inter-meeting time between any two mobile nodes is exponentially distributed. Not mention the fact that such assumption is only an approximation, it cannot be applied by network planners to directly control the mobile nodes for any network optimization, e.g., energy efficiency. It is quite significant to study the relationship between the network performance with the parameters that can be adjusted directly to tackle the limitations of current exponential distribution assumption based analysis. Therefore, in this paper, we are motivated to jointly consider the transmission range and messages residence time to stochastically analyze deadline-constrained message delivery ratio utilizing a controlled epidemic routing. The message propagation is considered as an age-structure process and described by a susceptible-infectious-recovered model, which is then analyzed using delay differential equations. Since both the transmission range and the message residence time are related to the mobile nodes' energy consumption, we further apply our analysis framework to investigate the tradeoff between the energy consumption and the achievable message delivery ratio. The correctness and accuracy of our analysis are validated by extensive simulations. [ABSTRACT FROM AUTHOR]

Currently, working in the overcrowded shared unlicensed spectrum band, leads to a reduction in the quality of communications in wireless networks. This makes a considerable increase in packet loss caused by collisions that necessitates packets retransmissions. In the case of wireless sensor networks (WSN), a large amount of energy of sensor nodes will be wasted by these retransmissions. Cognitive radio technology makes it possible for sensor nodes, to opportunistically use licensed bands with better propagation characteristics and less congestion. In this paper a routing method for cognitive radio wireless sensor networks (CR-CEA) is presented, that is based on a cross-layer design that jointly considers route and spectrum selection. The CR-CEA method has two main phases: next hop selection and channel selection. The routing is performed hop-by-hop with local information and decisions, which are more compatible with sensor networks. Primary user activity and prevention from interference with them, is considered in all spectrum decisions. It uniformly distributes frequency channels between adjacent nodes, which lead to a local reduction in collision probability. This clearly affects energy consumption in all sensor nodes. In CR-CEA, route selection is energy-aware and a learning-based technique is used to reduce the packet delay in terms of hop-count. The simulation results reveal that by applying cognitive radio technology to WSNs and selecting a proper operating channel, we can consciously decrease collision probability. This saves energy of sensor nodes and improves the network lifetime. [ABSTRACT FROM AUTHOR]

This article considers the routing issues for user-centric network applications. User-centric network routing is a challenging problem because there may not always exist a complete stable path from an information source to its destination. In this article, we provide a brief overview on the state-of-the-art user-centric network routing schemes and discuss their performance in terms of data delivery ratio and delivery latency. We also present a few open research issues that are critical to user-centric network applications. [ABSTRACT FROM PUBLISHER]

Multimedia applications are characterized as delay-sensitive and high-bandwidth stipulating traffic sources. Supporting such demanding applications on cognitive radio sensor networks (CRSNs) with energy and spectrum constraints is a highly daunting task. In this paper, we propose a spectrum-aware cluster-based energy-efficient multimedia (SCEEM) routing protocol for CRSNs that jointly overcomes the formidable limitations of energy and spectrum. Clustering is exploited to support the quality of service (QoS) and energy-efficient routing by limiting the participating nodes in route establishment. In SCEEM routing, the number of clusters is optimally determined to minimize the distortion in multimedia quality that occurs due to packet losses and latency. Moreover, the cluster-head selection is based on the energy and relative spectrum awareness such that noncontiguous available spectrum bands are clustered and scheduled to provide continuous transmission opportunity. Routing employs clustering with hybrid medium access by combining carrier-sense multiple access (CSMA) and time-division multiple access (TDMA). TDMA operates for intracluster transmission, whereas CSMA is used for intercluster routing. Thus, a cross-layer design of routing, i.e., of medium access control (MAC) and physical layers, provides efficient multimedia routing in CRSNs, which is revealed through simulation experiments. [ABSTRACT FROM PUBLISHER]

Hybrid networks constructed from cellular networks and delay- and disruption-tolerant networks (DTNs) are able to provide reliable communications to mobile nodes in base-station-starved areas regardless of node mobility or density. However, no routing scheme in DTNs has considered the adaptation to other networks, i.e., cellular networks. Thus, the reliability of message delivery is dependent on the position relationship between source nodes and base stations. In this paper, we propose an advanced routing scheme that controls the maximum number of replicas according to the distance between the source node and the nearest base station. Furthermore, we show how to decide the maximum number of replica messages for the distance from the base stations by analyzing the message delivery reliability of an existing DTN routing scheme. Additionally, we execute extensive computer simulations to evaluate the performance of our proposed routing scheme. Our results show that our proposed routing scheme keeps the required reliability regardless of the source node location. [ABSTRACT FROM PUBLISHER]

Disruption-tolerant networks (DTNs) are sparse mobile ad hoc networks where nodes connect with each other intermittently and end-to-end communication paths do not exist. Data routing in DTNs is challenging and has drawn much attention from research communities recently. Although many DTN routing strategies have been proposed in the past, they confront problems such as blind spots and dead ends and lack efficient implementation in a decentralized, large-scale, mobile, and dynamic environment. To overcome these difficulties, we introduce a new solution for DTNs that leverages the social properties and mobility characteristics of users. Our observation of the mobile trajectories of three data sets collected from real DTNs reveals that user movements appear locally and they tend to form communities correlated to geographic locations. Based on these findings, we propose a social- and mobile-aware routing strategy (SMART). It exploits a distributed community partitioning algorithm to divide the DTN into smaller communities regarding user locations and interaction routines. For intracommunity communications, a decayed routing metric convoluting social similarity and social centrality is calculated, which is used to decide forwarding node efficiently while avoiding the blind-spot and dead-end problems. To enable efficient intercommunity communications, we choose the fringe nodes that travel remotely as relays, and we propose the node-to-community utilities for routing decision across communities. We present empirical analysis to show that SMART reduces the occurrence of blind spots and dead ends to a level below 1%. The efficiency of SMART is evaluated by extensive trace-driven experiments, which illustrate that it outperforms other routing strategies in various real DTN traces. [ABSTRACT FROM PUBLISHER]

Wireless Sensor Networks (WSN) have proven to be exceedingly useful in varied real world applications, solving critical and sometimes lifesaving problems. WSNs are being used to detect forest fires, landslides, earthquakes, study marine biology, air quality, etc. They have also found useful applications in military, industrial settings and security monitoring. Due to such a wide variety of applications, each having different and sometimes unique set of requirements, new contributions are continuously being made. In this paper, we first outline the main design considerations and goals for developing routing protocols for WSNs. Then we use these design parameters as a framework to survey some of the recently proposed routing protocols for WSNs. Finally we do a performance and feature comparison of these protocols. [ABSTRACT FROM AUTHOR]

Vehicular ad hoc network (VANET) is a communication network used for vehicle to vehicle interaction and this network is different from other wireless networks. Geographical Routing Protocol (GRP) is used in VANETs. This study proposes a Fuzzy Quality of Service GRP (FQ_GRP) to enhance the performance of GRP routing. Link quality, traffic density and number of intersections are inputs to a fuzzy system and the fuzzy controller output is next hop selection. Simulations are conducted with 40 nodes around 9 square kilometers. The proposed FQ_GRP routing scheme, distributes the traffic through nodes so that the throughput is increased and average latency reduced. The proposed method achieves better throughput and lower end to end delay compared to traditional GRP. [ABSTRACT FROM AUTHOR]

ABSTRACT The usability of wireless sensor networks in modern applications requires the fulfillment of dynamic Quality of Service (QoS) requirements that can only be met in a reactive manner by the introduction of composite routing metrics, capturing several distinct network characteristics. However, combining routing metrics is neither a trivial nor an arbitrary task, given the routing protocol requirements and routing metrics properties. In this paper, the theoretical framework of routing algebra formalism is adopted and extended to incorporate single or composite routing metrics, because the satisfaction of routing algebra properties ensures convergence, optimality, and loop-freeness. Moreover, packet forwarding indication is defined as a new trust metric for systems (a) with or (b) without network retransmissions to avoid forwarding attacks, while a novel composite routing metric is presented, combining link reliability and trust-awareness in an additive manner, fulfilling the theoretical requirements. Finally, this composite metric is applied to the Routing Protocol for Low Power and Lossy Networks via simulations, which verify its efficiency in several scenarios, including the comparison between lexical and additive metric composition approaches. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

An approach for cell routing using gridded design rules is proposed. It is technology-independent and parameterizable for different fabrics and design rules, including support for multiple-patterning lithography. The core contribution is a detailed-routing algorithm based on a Boolean formulation of the problem. The algorithm uses a novel encoding scheme, graph theory to support floating terminals, efficient heuristics to reduce the computational cost, and minimization of the number of unconnected pins in case the cell is unroutable. The versatility of the algorithm is demonstrated by routing single- and double-height cells. The efficiency is ascertained by synthesizing a library with 127 cells in about one hour and a half of CPU time. The layouts derived by the implemented tool have also been compared with the ones from a commercial library; thus, showing the competitiveness of the approach for gridded geometries. [ABSTRACT FROM PUBLISHER]

Most of the nodes in ad hoc networks rely on batteries, which requires energy saving. Hence, numerous energy-efficient routing algorithms have been proposed for solving this problem. In this paper, we exploit the benefits of cross-layer information exchange, such as the knowledge of the Frame Error Rate (FER) in the physical layer, the maximum number of retransmissions in the Medium Access Control (MAC) layer and the number of relays in the network layer. Energy-consumption-based Objective Functions (OF) are invoked for calculating the end-to-end energy consumption of each potentially available route for both Traditional Routing (TR) and for our novel Opportunistic Routing (OR), respectively. We also improve the TR and the OR with the aid of efficient Power Allocation (PA) for further reducing the energy consumption. For the TR, we take into account the dependencies amongst the links of a multi-hop route, which facilitates a more accurate performance evaluation than upon assuming the links that are independent. Moreover, two energy-efficient routing algorithms are designed based on Dijkstra's algorithm. The algorithms based on the energy OF provide the theoretical bounds, which are shown to be close to the bound found from exhaustive search, despite the significantly reduced complexity of the former. Finally, the end-to-end throughput and the end-to-end delay of this system are analyzed theoretically and a new technique of characterizing the delay distribution of OR is proposed. The simulation results show that our energy-efficient OR outperforms the TR and that their theoretical analysis accurately matches the simulation results. [ABSTRACT FROM PUBLISHER]

One of the purposes of network tomography is to infer the status of parameters (e.g., delay) for the links inside a network through end-to-end probing between (external) boundary nodes along predetermined routes. In this work, we apply concepts from compressed sensing and expander graphs to the delay estimation problem. We first show that a relative majority of network topologies are not expanders for existing expansion criteria. Motivated by this challenge, we then relax such criteria, enabling us to acquire simulation evidence that link delays can be estimated for 30% more networks. That is, our relaxation expands the list of identifiable networks with bounded estimation error by 30%. We conduct a simulation performance analysis of delay estimation and congestion detection on the basis of l_1 minimization, demonstrating that accurate estimation is feasible for an increasing proportion of networks. [ABSTRACT FROM PUBLISHER]

A novel position-based routing protocol anchor-based connectivity-aware routing (ACAR) for vehicular ad hoc networks (VANETs) is proposed in this paper to ensure connectivity of routes with more successfully delivered packets. Both buses and cars are considered as vehicular nodes running in both clockwise and anticlockwise directions in a city scenario. Both directions are taken into account for faster communication. ACAR is a hybrid protocol, using both the greedy forwarding approach and the store-carry-and-forward approach to minimize the packet drop rate on the basis of certain assumptions. Our solution to situations that occur when the network is sparse and when any (source or intermediate) node has left its initial position makes this protocol different from those existing in the literature.We consider only vehicle-to-vehicle (V2V) communication in which both the source and destination nodes are moving vehicles. Also, no road-side units are considered. Finally, we compare our protocol with A-STAR (a plausible connectivity-aware routing protocol for city environments), and simulation results in NS-2 show improvement in the number of packets delivered to the destination using fewer hops. Also, we show that ACAR has more successfully-delivered longdistance packets with reasonable packet delay than A-STAR. [ABSTRACT FROM AUTHOR]

Behavioral patterns prediction in the context of Vehicular Ad hoc Networks (VANETs) has been receiving increasing attention due to the enabling of on-demand, intelligent traffic analysis and real-time responses to traffic issues. One of these patterns, sequential patterns, is a type of behavioral pattern that describes the occurrence of events in a timely and ordered fashion. In the context of VANETs, these events are defined as an ordered list of road segments traversed by vehicles during their trips from a starting point to their final intended destination. In this paper, a new set of formal definitions depicting vehicular paths as sequential patterns is described. Also, five novel communication schemes have been designed and implemented under a simulated environment to collect vehicular paths; such schemes are classified under two categories: RSU (Road Side Unit)-based and Vehicle-based. After collection, extracted frequent paths are obtained through data mining, and the probability of these frequent paths is measured. In order to evaluate the effectiveness and efficiency of the proposed schemes, extensive experimental analysis has been realized. [ABSTRACT FROM AUTHOR]

Routing Protocols in MANETs have been researched for peer-to-peer services in general. Furthermore, these protocols have been concerned with the fairness service amongst nodes’ peers. However, most of those protocols aren’t suitable for the data communication especially in hierarchical networks, where the most data flows are vertical like a monitoring system. Furthermore, for the monitoring system, amongst the nodes, one of them (a.k.a. root node) should be employed as a gateway to connect to Internet. Thus, most reporting data from certain nodes are delivered to the root node. Likewise, data should be delivered to the message originator nodes for responsibility. Therefore, a new routing protocol for such networks including the monitoring system is strongly required. This paper proposes a routing protocol based on the binary-tree shaped network, which derives from the general table driven methods’ routing manners with DSDV families of MANETs. In conclusion, we verify whether our protocol would be efficiently used in such networks through its performance evaluations with simulation results. [ABSTRACT FROM AUTHOR]

Mobile Ad-Hoc Networks (MANETs) are autonomous and decentralized wireless systems. Mobile Ad hoc Network is a collection of mobile nodes in which the wireless links are frequently broken down due to mobility and dynamic infrastructure. Routing is a significant issue and challenge in ad hoc networks. Many Routing protocols have been proposed so far to improve the routing performance and reliability. This research paper describes the characteristics of ad hoc routing protocols Ad-hoc On Demand Distance Vector Routing (AODV), Dynamic Source Routing (DSR), Hybrid Routing (ZRP) based on the performance metrics like Average delay, Throughput under low mobility and low traffic network as well as under high mobility and high traffic network for Black hole effect and Daniel of Service(DoS) using NS-2. Results show that AODV has maximum throughput under low traffic and DSDV has maximum throughput under high traffic. As network becomes dense DSR perform well in terms of Throughput than AODV and DSR and ZRP. [ABSTRACT FROM AUTHOR]

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

Energy saving in telecommunications networks has become a well established topic in the research community. We look at the electrical and optical layers of IP-over-WDM networks, and present a list of evaluation criteria for energy- aware adaptive routing solutions (EA-ARSs) from the perspective of a network operator. Furthermore, we briefly explain the adaptive routing solutions originating from the European Union?s TREND and the FP7 Network of Excellence, show saving of energy consumed by line cards in a reference scenario, and use the evaluation criteria to identify the next steps toward introduction of the EA-ARSs into real operation. [ABSTRACT FROM PUBLISHER]

SUMMARY Because inter-satellite links (ISLs) among the distributed satellite nodes can be used to support autonomous control in satellite system operation to reduce dependency on the ground stations, it becomes a popular communication paradigm for the future satellite systems. However, this introduces great technical challenges, particularly for routing protocol to support such space communication system. Facing the challenges, we present out study of routing technology in this paper tailored for satellite network of MEO (Table 1) and IGSO with ISLs in addition to satellite-ground links. The study aims to explore the routing strategies and algorithms of satellite network based on the evolution law of network topology to provide reference design for data exchange in autonomous satellite system. A comprehensive investigation, ranging from the analysis of relevant factors affecting data exchange in satellite networks to the primary application and resource constraints in designing satellite routing strategy, has been conducted. Our main contribution is to propose an on-demand computing and caching centralized routing strategy and algorithm on the satellite network. The routing strategy and algorithm is designed for satellite network topology dynamic grouping. The route calculation for user data transmission is divided into three phases: direction estimation, direction enhancement, and congestion avoidance. The strategy and algorithm provide significant advantages of high efficiency, low complexity, and flexible configuration, by which the satellite networks can provide the features of flexible configure, efficient transferring, easy management, structural survivability, and great potential in scalability. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

SUMMARY In IP-based networks, IP address uniqueness is one of the most important requirements since a node has to participate in unicast communications and routing. Often nodes are assumed to have unique IP addresses configured a priori. However, this is not the case and cannot be achieved easily in mobile ad hoc networks (MANETs). Most of the existing dynamic address allocation schemes of MANET rely on network-wide flooding for address solicitation and/or duplicate address detection. As a result, several types of security threats can be seen at the time of address allocation. In this paper, we present an ID-based distributed dynamic IP configuration scheme that securely allocates IP addresses to the authorized nodes without flooding the entire network. Here each node acquires capability of generating unique IP addresses from its own IP address and can assign those addresses to the new nodes. The proposed scheme provides security against the associated threats with dynamic IP allocation protocol without the help of a trusted third party. It also efficiently handles the network partitioning and merging and reduces the chance of address conflicts. Performance analysis and simulation results are present to show that the proposed addressing scheme has low communication overhead and fairly low addressing latency with added security mechanisms compared to the similar existing dynamic address allocation schemes. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT Because of the dynamic nature of delay tolerant networks (DTNs), many replication-based routing schemes were proposed to increase the probability of delivery by making multiple copies of each message. In such schemes, one concern is how many replicas of a message should be distributed in the network. In this paper, we propose a routing scheme for DTNs, called adaptive spraying based on the intercontact time (ASBIT). The scheme is based on the idea of that each node dynamically chooses the right number of message copies disseminated to respond to the current conditions of the network. When forwarding, ASBIT selects the node with a higher centrality as the next hop, and utilises the multi-attribute decision making theory for the division of the replication number between two nodes. Simulation results show that ASBIT achieves comparable delivery ratio and delivery delay while maintaining lower overhead compared with some well-known routing schemes in sparse scenarios. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Location information to be up to-date is a fundamental operation in position-based routing protocols for mobile ad hoc networks. The location information accuracy level depends on beacon sending frequency and the neighbors' entries timeout period. This instigates the need for dynamic updating approach with improved technique to refresh neighbors' entries in a node's neighbors' matrix (NLM). This paper presents a dynamic beaconing update mechanism (DBUM). In the DBUM, the mobile nodes dynamically adjust their beacon intervals based on pre-specified tolerance deviation distance by using the dynamic fuzzy logic controller. Moreover, with DBUM, a node applies the residual link lifetime with its neighboring node to refresh their entries in its NLM. Compared with the existing algorithms, evaluation results reveal that the proposed DBUM algorithm increases the accuracy of a node's information in its NLM matrix and achieves high packet delivery ratio at the expense of negligible overhead increment. [ABSTRACT FROM AUTHOR]

Delay Tolerant Networks (DTNs) provide message delivery services to users via intermittently connected nodes. In DTNs, routing is one of the most challenging issues since end-to-end connectivity between nodes may not be available most of the time. Although many routing protocols for DTNs have been proposed, they do not achieve satisfactory performance, since they exploit only some of the network characteristics. In this paper, we present a new DTN routing protocol, called the Link Contact Duration-based Routing Protocol (LCD). Like existing protocols, LCD uses the disconnect duration of a link between two nodes to find the routing path with the shortest end-to-end delay. In addition, LCD uses the contact duration of a link and the number of buffered messages to deliver as many messages as possible in a short time. Our simulation results show that LCD has better performance than existing DTN routing protocols. [ABSTRACT FROM AUTHOR]

Cooperative communication (CC) allows multiple nodes to simultaneously transmit the same packet to the receiver so that the combined signal at the receiver can be correctly decoded. Since the CC can reduce the transmission power and extend the transmission coverage, it has been considered in minimum energy routing protocols to reduce the total energy consumption. However, previous research on cooperative routing only focuses on minimizing the total energy consumption from the source node to the destination node, which may lead to the unbalanced energy distribution among nodes. In this paper, we aim to study the impact of cooperative routing on balancing the energy distribution among nodes. By introducing a new routing scheme which carefully selects cooperative relay nodes and assigns their transmission power, our cooperative routing method can balance the remaining energy among neighboring nodes to maximize the lifetime of the network. Simulation results demonstrate that the proposed cooperative routing algorithm significantly balances the energy distribution and prolongs the lifetime of the network. [ABSTRACT FROM AUTHOR]

Mobile Ad Hoc Network (MANET) is a collection of wireless mobile nodes dynamically forming a temporary network without the use of any existing network infrastructure or centralized administration. Mobile Ad Hoc Networks (MANETs) have the attributes such as wireless connection, continuously changing topology, distributed operation and easy of deployment. Each node operates not only as an end system, but also as a router to forward packets. Routing in MANETs has been a challenging task ever since the wireless networks came into existence. The MANET routing protocols can be broadly classified into two classes: Proactive routing protocols (or table-driven routing protocols) and Reactive routing protocols (or on-demand routing protocols). In this research work we have compared the performance of two Proactive routing protocols: DSDV and OLSR, along with AODV as a Reactive routing protocol using Random Waypoint (RWP) Mobility Model, Freeway (FW) Mobility Model, Manhattan Grid (MH) Mobility Model and Reference Point Group (RPGM) Mobility Model using Network Simulator (NS-2.34). These four Mobility Models are selected to represent the possibility of practical application in future such as movement of nodes on Highway, in urban area, in groups such as movement in military battlefield etc. [ABSTRACT FROM AUTHOR]

We propose a new multipath-based reliable routing protocol on MANETs, Multipath-based Reliable routing protocol with Fast-Recovery of failures (MRFR). For reliable message transmission, MRFR tries to find the most reliable path between a source and a destination considering the end-to-end packet reception reliability of the routes. The established path consists of a primary path that is used to transmit messages, and the secondary paths that are used to recover the path when detecting failures on the primary path. After establishing the path, the source transmits messages through the primary path. If a node detects a link failure during message transmission, it can recover the path locally by switching from the primary to the secondary path. By allowing the intermediate nodes to locally recover the route failure, the proposed protocol can handle the dynamic topological change of the MANETs efficiently. The simulation result using the QualNet simulator shows that the MRFR protocol performs better than other protocols in terms of the end-to-end message delivery ratio and fault-tolerance capability. [ABSTRACT FROM AUTHOR]

We study a simple network with two parallel batch-service queues, where service at a queue commences when the batch is full and each queue is served by infinitely many servers. A stream of general arrivals observe the current state of the system on arrival and choose which queue to join to minimize their own expected transit time. We show that for each set of parameter values there exists a unique user equilibrium policy and that it possesses various monotonicity properties. User equilibrium policies for probabilistic routing are also discussed and compared with the state-dependent setting. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discusses various reports within the issue on topics including energy consumption in resilient telecommunication network, triangle inequalities and path routing problems.

Rate region precisely measures the transmission ability of a network. Three graph processing techniques are presented: reduced graph, union reduced graph, and virtual node. Applying these techniques, an operable method to completely solve the calculation of rate regions for unicast routing networks is developed. The correctness of the method is proved theoretically and illustrated with an example. This method is helpful in both theoretical perspective and industrial implementation. [ABSTRACT FROM AUTHOR]