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Dynamic multipath routing gives users flexibility over the transmitting path to deliver messages for security. Several protocols have already presented, such as multipath TCP, random routing mutation. However, they often limited to scalability, which mainly reflects on two aspects of network resource consumption and compossibility with other main transfer protocols. In this paper, to enhance the security of data delivery in wide area networks, a novel multipath routing scheme for end‐to‐end communication is proposed. The basic idea is concurrently using two paths (a fixed path and a changing path) to deliver the data of a pair, the fixed routing path undertakes the main delivery tasks, and the continually changing routing path only transfers a little data of the flow during the whole communication period. For systematically achieving security, Information Dispersal Algorithm disperses the flow data over the two paths for resisting anyone routing path compromised. Further, the method can maintain more routing path change since the burst network resource requirement decreases significantly at the routing mutation moment. Meanwhile, it brings a small amount of bandwidth disturbance over the traffic statuses of the network, thus alleviating instead of worsening the compossibility with other protocols. [ABSTRACT FROM AUTHOR]

On the one hand, the correctness of routing protocols in networks is an issue of utmost importance for guaranteeing the delivery of messages from any source to any target. On the other hand, a large collection of routing schemes have been proposed during the last two decades, with the objective of transmitting messages along short routes, while keeping the routing tables small. Regrettably, all these schemes share the property that an adversary may modify the content of the routing tables with the objective of, e.g. blocking the delivery of messages between some pairs of nodes, without being detected by any node. In this paper, we present a simple certification mechanism which enables the nodes to locally detect any alteration of their routing tables.In particular, we show how to locally verify the stretch-3 routing scheme by Thorup and Zwick, presented in SPAA in 2001, by adding certificates of the same order of magnitude as the original routing tables. We also propose a new name-independent routing scheme using routing tables of size O ˜ (n) bits at each node in n -node networks. This new routing scheme can be locally verified using certificates of O ˜ (n) bits. Its stretch is 3 if using handshaking, and 5 otherwise. [ABSTRACT FROM AUTHOR]

Identifying congested links accurately to ensure the Service Level Agreements is an important but challenging task, since it is costly or even practically unfeasible to monitor massive interior links directly for large networks. Network tomography has been proposed to overcome this problem by using end-to-end (path) measurements. However, most of existing tomographic methods only focus on the loss performance degradation, while paying much less attention the fact that network congestion will also greatly worsen the delay performance. Nevertheless, most of them normally work under single-path routing, which may also get violated in today's Internet as multipath routing is increasingly common. In this paper, we consider the problem of using end-to-end measurements to identify congested links when multipath routing is employed in a non-tree network. Firstly, we use both link delay variances and link loss rates to model the system constraints between end- to-end paths and the interior links, and transfer the issue of congested link identification as an optimization problem. By theoretically demonstrating that the link delay variances are identifiable from the end-to-end delay measurements with certain topology conditions, we further prove that the above optimization problem is a Non-deterministic Polynomial-time hard (NP-hard) problem. Then in order to solve such an NP-hard problem, two greedy algorithms based on bool and additive congestion statuses are proposed. Lastly, simulation studies show that with extra delay constraints, our proposed algorithms are able to achieve better identification performances than existing methods under multipath routing. [ABSTRACT FROM AUTHOR]

ARPANET demonstrated that packet switching was an effective routing principle for computer networks, accelerating the evolution towards the current network paradigm, in which packetization is found in almost all forms of digital communication. The decision to use the packet switching principle was crucial to the development of the Internet and computer networking broadly, and in popular literature, packet switching is often attributed to three originators: Paul Baran, Donald Davies and Leonard Kleinrock. This paper does not concern itself with who invented packet switching, but rather, who had the greatest influence on the risky and highly consequential decision to base the ARPANET design on this previously untested technology. A close examination of the available documentation, including two newly re-emerged documents, indicate that Paul Baran had a much more substantial influence on the decision to use packet switching for ARPANET than most retellings of Internet history portray. The findings also show that Donald Davies' role in the adoption of packet switching as a dominant principle for digital communication may have been less impactful than depicted in current literature and that Kleinrock may have played a significant role in bringing packet switching to the ARPANET, influenced by interactions with Baran. [ABSTRACT FROM AUTHOR]

We study problems that integrate buy-at-bulk network design into the classical (connected) facility location problem. In such problems, we need to open facilities, build a routing network, and route every client demand to an open facility. Furthermore, capacities of the edges can be purchased in discrete units from K different cable types with costs that satisfy economies of scale. We extend the linear programming framework of Talwar (IPCO 2002) for the single-source buy-at-bulk problem to these variants and prove integrality gap upper bounds for both facility location and connected facility location buy-at-bulk problems. For the unconnected variant we prove an integrality gap bound of O(K), and for the connected version, we get the first LP-based bound of O(1). [ABSTRACT FROM AUTHOR]

The characteristics of MANET such as decentralized architecture, dynamic topologies make MANETs susceptible to various security attacks. Sequence number attacks are such type of security threats which tend to degrade the network functioning and performance by sending fabricated route reply packets (RREP) with the objective of getting involved in the route and drop some or all of the data packets during the data transmission phase. The sequence number adversary attempts to send a fabricated high destination number in the RREP packet which attracts the sender to establish a path through the adversary node. This paper proposes a proactive secure routing mechanism which is an improvement over the authors previously proposed scheme. It makes use of linear regression mechanism to predict the maximum destination sequence number that the neighboring node can insert in the RREP packet. As an additional security checkpoint, it uses a bait detection mechanism to establish confidence in marking a suspicious node as a malicious node. The proposed approach works in collaboration with the ad hoc on-demand distance vector routing (AODV) protocol. The simulation results depict that the approach improves the network performance in the presence of adversaries as compared to previously proposed scheme. [ABSTRACT FROM AUTHOR]

The end-to-end throughput of multi-hop communication in wireless ad hoc networks is affected by the conflict between forwarding nodes. It has been shown that sending more packets than maximum achievable end-to-end throughput not only fails to increase throughput but also decreases throughput owing to high contention and collision. Accordingly, it is of crucial importance for a source node to know the maximum end-to-end throughput. The end-to-end throughput depends on multiple factors, such as physical layer limitations, medium access control (MAC) protocol properties, routing policy, and nodes’ distribution. There have been many studies on analytical modeling of end-to-end throughput but none of them has taken routing policy and nodes’ distribution as well as MAC layer altogether into account. In this paper, the end-to-end throughput with perfect MAC layer is obtained based on routing policy and nodes’ distribution in 1-D and 2-D networks. Then, imperfections of IEEE 802.11 protocol are added to the model to obtain precise value. An exhaustive simulation is also made to validate the proposed models using ns-2 simulator. Results show that if the distribution to the next hop for a particular routing policy is known, our methodology can obtain the maximum end-to-end throughput precisely. [ABSTRACT FROM AUTHOR]

Routing is one of the most important technologies in wireless sensor networks. The energy efficiency of the sensor network is realized by combining other technologies with routing protocols in this paper. First, through the analysis of the energy model of the clustering routing algorithm, the local signal to noise ratio (SNR) is used to purposefully select the nodes in the cluster to transmit data. In order to avoid the energy consumption of a large number of nodes to transmit data, a simple architecture is proposed to combine the distributed source code with the cluster routing protocol. The method uses the data on the cluster head as the edge information to decode the compressed information transmitted from the cluster nodes. The simulation result shows that the energy efficiency of the network can be achieved through this combination. [ABSTRACT FROM AUTHOR]

Summary: A smart opportunistic environment is a physical space, which allows the smart physical objects to communicate in the presence of disruption in connectivity. Because, the objects in such an environment are buffer constrained, some of the objects will not participate in data forwarding, when there is scarcity of storage (buffer) space. In this paper, we focus on such selfish behavior of objects triggered by space constraints in a smart opportunistic environment. We propose a novel data forwarding algorithm, selfishness and buffer‐aware routing (SBR), in which a node is chosen as a relay, based on its capability, which is a function of its available buffer space and past encounter history (delivery predictability) with the destination. SBR can efficiently utilize the limited buffer space in a node with a buffer management scheme, WSD. It can also detect space constraint driven selfish behavior of nodes and resolve it using a reputation‐based technique, MSD. We have conducted simulation using both synthetic and real‐world traces for evaluating our proposed SBR algorithm. For analyzing the performance of the algorithm in real‐time, a smart vehicular test‐bed is developed. Simulation results and test‐bed implementation show that our algorithm performs better in terms of higher delivery ratio, lower overhead ratio, and lower delivery delay, compared with existing opportunistic data forwarding algorithms. [ABSTRACT FROM AUTHOR]

In recent years, the idea of wireless three-dimensional network-on-chips (3D NoCs) was promoted in order to design many-core chips with greater performance and lower energy consumption. This technology is the combination of different dies that are stacked on each other. Therefore, it is necessary to propose a suitable routing mechanism for irregular wireless 3D NoCs that can support the agnostic topologies. In this paper, we propose a deadlock-free routing algorithm for wireless 3D NoCs, called Floyd-base Inter-chip Traffic distribution (FIT), which is based on Floyd routing algorithm. In FIT algorithm, the number of hops is reduced compared to the already established deterministic algorithms; moreover, the traffic distribution is improved. Evaluation results show that our proposed routing algorithm significantly improves the performance and throughput by reducing the energy consumption, the average hop count and the communication latency. [ABSTRACT FROM AUTHOR]

Three major problems of wireless sensor networks can be summarized into communication traffic, energy consumption and routing security. In this paper, we analyze performance of an underwater sensor network in dense mode under creation of spherical division-based forbidden regions. Obviously, unnecessary smart node removal from the packet forwarding process of a flooding-based routing policy is theoretically an idea for enhancing the known network parameters. In this research, our purposed approach is to improve energy consumption by using a removal process over physical routing space toward more network reliability and better network lifetime. Clearly, our aim is performance improvement in terms of a network protocol in an underwater wireless sensor networks with a huge number of high-speed mobile nodes. The nodes generally consist of different underwater instruments such as sensors, robots, modems and batteries and are categorized into two groups of autonomous unmanned underwater vehicles and remotely operated vehicles. The proposed approach is a hybrid solution based on vector-based forwarding routing protocol and spherical divisions which is named spherical division-based vector-based forwarding. The proposed protocol can successfully reduce energy consumption and equivalently increase the network lifetime while packet delivery ratio is in a saturation level. In details, our proposed method works on preservation of sensors’ energy in which we physically remove some additional paths of routing process (based on a multipath forwarding using a basic routing algorithm). In this regard, we apply a spherical division-based physical restriction on the routing space. However, removing these additional sensor nodes/routers is conditionally done under keeping the suitable traffic performance in terms of PDR because it is essential to say that a new scheme is effective. [ABSTRACT FROM AUTHOR]

Greedy Forward is a well-known technique used by most of the geographic routing algorithms to forward packets to the node that is geographically closer to the destination node. It is the simplest form of the proposed geographic routing algorithms and it is particularly attractive in sensor networks by bringing additional advantages such scalability, dynamism, and high delivery rates. However, in the presence of a hole (or voids), greedy forward techniques tend to fail. Thus, a hole bypass solution needs to be used in order to route packets to a node where greedy forwarding process can be resumed. In this work, we propose a new geographic routing algorithm called REACT that can bypass routing holes and create routing paths toward the sink node. Our solution takes advantage of the higher communication range of the sink node and the Received Signal Strength Indicator (RSSI) to enable the construction of routing paths by self-electing the next hop at each step while also performing data aggregation. No extra packets are required to configure the routing task. Our results clearly show an efficient data delivery achieved by the proposed algorithm in scenarios with routing holes with all the benefits of a greedy forwarding technique. [ABSTRACT FROM AUTHOR]

In this paper, we proposed and developed Function-Oriented Networking (FON), a platform for network users. It has a different philosophy as opposed to technologies for network managers of Software-Defined Networking technology, OpenFlow. It is a technology that can immediately reflect the demands of the network users in the network, unlike the existing OpenFlow and Network Functions Virtualization (NFV), which do not reflect directly the needs of the network users. It allows the network user to determine the policy of the direct network, so it can be applied more precisely than the policy applied by the network manager. This is expected to increase the satisfaction of the service users when the network users try to provide new services. We developed FON function that performs on-demand routing for Low-Delay Required service. We analyzed the characteristics of the Ant Colony Optimization (ACO) algorithm and found that the algorithm is suitable for low-delay required services. It was also the first in the world to implement the routing software using ACO Algorithm in the real Ethernet network. In order to improve the routing performance, several algorithms of the ACO Algorithm have been developed to enable faster path search-routing and path recovery. The relationship between the network performance index and the ACO routing parameters is derived, and the results are compared and analyzed. Through this, it was possible to develop the ACO algorithm. [ABSTRACT FROM AUTHOR]

We design throughput-optimal dynamic broadcast algorithms for multi-hop networks with arbitrary topologies. Most of the previous broadcast algorithms route packets along spanning trees. For large time-varying networks, computing and maintaining a set of spanning trees is not efficient, as the network-topology may change frequently. In this paper, we design a class of dynamic algorithms, which make simple packet-by-packet scheduling and routing decisions, and hence obviate the need for maintaining any global topological structures, such as spanning trees. Our algorithms may be conveniently understood as a non-trivial generalization of the familiar back-pressure algorithm for unicast traffic, which performs packet routing and scheduling based on queue lengths. However, in the broadcast setting, due to packet duplications, it is difficult to define appropriate queuing structures. We design and prove the optimality of a virtual queue-based algorithm, where virtual queues are defined for subsets of nodes. We then propose a multi-class broadcast policy, which combines the above scheduling algorithm with in-class-in-order packet forwarding, resulting in significant reduction in complexity. Finally, we evaluate the performance of the proposed algorithms via extensive numerical simulations. [ABSTRACT FROM PUBLISHER]

Legacy networks are often designed to operate with simple single-path routing, like the shortest path, which is known to be throughput suboptimal. On the other hand, previously proposed throughput optimal policies (i.e., backpressure) require every device in the network to make dynamic routing decisions. In this paper, we study an overlay architecture for dynamic routing, such that only a subset of devices (overlay nodes) need to make the dynamic routing decisions. We determine the essential collection of nodes that must bifurcate traffic for achieving the maximum multi-commodity network throughput. We apply our optimal node placement algorithm to several graphs and the results show that a small fraction of overlay nodes is sufficient for achieving maximum throughput. Finally, we propose a threshold-based policy (BP-T) and a heuristic policy (OBP), which dynamically control traffic bifurcations at overlay nodes. Policy BP-T is proved to maximize throughput for the case when underlay paths do no overlap. In all studied simulation scenarios, OBP not only achieves full throughput but also reduces delay in comparison to the throughput optimal backpressure routing. [ABSTRACT FROM PUBLISHER]

Network switches and routers need to serve packet writes and reads at rates that challenge the most advanced memory technologies. As a result, scaling the switching rates is commonly done by parallelizing the packet I/Os using multiple memory units. For improved read rates, packets can be coded upon write, thus giving more flexibility at read time to achieve higher utilization of the memory units. This paper presents a detailed study of coded network switches, and in particular, how to design them to maximize the throughput advantages over standard uncoded switches. Toward that objective, the paper contributes a variety of algorithmic and analytical tools to improve and evaluate the throughput performance. The most interesting finding of this paper is that the placement of packets in the switch memory is the key to both high performance and algorithmic efficiency. One particular placement policy we call “design placement” is shown to enjoy the best combination of throughput performance and implementation feasibility. [ABSTRACT FROM PUBLISHER]

This paper investigates the problem of finding optimal paths in single-source single-destination accumulative multi-hop networks. We consider a single source that communicates to a single destination assisted by several relays through multiple hops. At each hop, only one node transmits, while all the other nodes receive the transmitted signal, and store it after processing/decoding and mixing it with the signals received in previous hops. That is, we consider that terminals make use of advanced energy accumulation transmission/reception techniques, such as maximal ratio combining reception of repetition codes, or information accumulation with rateless codes. Accumulative techniques increase communication reliability, reduce energy consumption, and decrease latency. We investigate the properties that a routing metric must satisfy in these accumulative networks to guarantee that optimal paths can be computed with Dijkstra’s algorithm. We model the problem of routing in accumulative multi-hop networks, as the problem of routing in a hypergraph. We show that optimality properties in a traditional multi-hop network (monotonicity and isotonicity) are no longer useful and derive a new set of sufficient conditions for optimality. We illustrate these results by studying the minimum energy routing problem in static accumulative multi-hop networks for different forwarding strategies at relays. [ABSTRACT FROM PUBLISHER]

Delay-tolerant networks (DTNs) are intermittently connected networks, such as mobile social networks formed by human-carried mobile devices. Routing in such mobile social DTNs is very challenging, as it must handle network partitioning, long delays, and dynamic topology. Recently, social-based approaches, which attempt to exploit social behaviors of DTN nodes to make better routing decision, have drawn tremendous interest in the DTN routing design. In this paper, we propose a novel social-based routing approach for mobile social DTNs, where a new metric, i.e., social energy, is introduced to quantify the ability of a node to forward packets to others, inspired by general laws in particle physics. Social energy is generated via node encounters and shared by the communities of encountering nodes. Similar to the radiation of energy in physics, the social energy of any node decays over time. Our proposed social-energy-based routing (SEBAR) protocol considers social energy of encountering nodes and is in favor of the node with a higher social energy in its or the destination's social community. Our simulations with real-life wireless traces demonstrate the efficiency and the effectiveness of the SEBAR method by comparing it with several existing DTN routing schemes. In addition, two variations of SEBAR with the aim of overhead reduction are also presented and evaluated. [ABSTRACT FROM AUTHOR]

Modern technologies provide wide and thick metal layers that must be wisely used to reduce the delay of critical interconnections. After global routing, incremental layer assignment can improve the circuit timing by properly selecting critical interconnect segments to be routed in the faster (but very limited) wires on upper layers. Existing techniques based on net-by-net iterative improvement may get stuck at locally-optimal solutions depending on net ordering. Recent techniques rule out such drawback through the simultaneous iterative improvement of all nets, but they unfortunately rely on objective functions that may guide the optimization off critical paths. As opposed to all reported techniques, which rely on simplified, overly pessimistic timing models, this paper proposes the decoupling of incremental layer assignment from the timing analysis and the exploitation of flow conservation conditions so as to enable the use of an external signoff timing engine. The novel technique was experimentally compared with two state-of-the art works, leading to 50% less timing violations under total negative slack metric and 35% less timing violations under worst negative slack metric with similar overhead in number of vias. [ABSTRACT FROM AUTHOR]

Triple patterning lithography (TPL) is one of the most promising lithography technology in sub-14-nm technology nodes, especially for complicated low metal layer manufacturing. To overcome the intracell routability problem and improve the cell regularity, recently middle-of-line (MOL) layers are employed in standard cell design. However, MOL layers may introduce a large amount of cross-row TPL conflicts for row-based design. Motivated by this challenge, in this paper we propose the first TPL aware detailed placement toward zero cross-row MOL conflict. In standard cell precoloring, Boolean-based look-up table is proposed to reduce solution space. In detailed placement stage, three powerful techniques, i.e., local reordered single row refinement, min-cost flow-based conflict removal, and local cell interleaving, are proposed to provide zero TPL conflict solution. The experimental results demonstrate the effectiveness of our proposed methodologies. [ABSTRACT FROM AUTHOR]

Due to the absence of infrastructure support, secure data dissemination is a challenging task in scalable mobile ad hoc networks (MANETs) environment. In most of the traditional routing techniques for MANETs, either security has not been taken into account or only one aspect of security concern has been addressed without optimizing the routing performance. This paper proposes Flooding Factor based Framework for Trust Management (F3TM) in MANETs. True flooding approach is utilized to identify attacker nodes based on the calculation of trust value. Route Discovery Algorithm is developed to discover an efficient and secure path for data forwarding using Experimental Grey Wolf algorithm for validating network nodes. Enhanced Multi-Swarm Optimization is used to optimize the identified delivery path. Simulations are carried out in ns2 to assess and compare the performance of F3TM with the state-of-the-art frameworks: CORMAN and PRIME considering the metrics including delay, packet delivery ration, overhead and throughput. The performance assessment attests the reliable security of F3TM compared to the state-of-the-art frameworks. [ABSTRACT FROM AUTHOR]

Internet of Things (IoT) enables the interaction of objects or things with each other or with the surrounding environment. "Smart" objects, embedded with RFID are the key element for IoT. These objects are provided with the unique identities which addresses each device uniquely in the network. Routing plays a major role in adapting the IoT vision as nodes must communicate and exchange information efficiently with each other. A major challenge for IoT is the design and implementation of routing algorithms that adapt to the frequent and randomly changing network topology. In this paper a multipath routing protocol for IoT that is MRPIoT has been proposed which adapts to the basic requirements of IoT network. In the proposed work an Internet Connecting Routing Table (ICRT) is used which consists of routing information as well as internet connecting nodes information thereby eliminating need to maintain separate table for internet connecting nodes information. We have analyzed and evaluated the performance of proposed protocol on the basis of parameters such as packet delivery ratio, energy consumption and throughput. [ABSTRACT FROM AUTHOR]

Forwarding decisions in classical IP-based networks are predetermined by routing. This is necessary to avoid loops, inhibiting opportunities to implement an adaptive and intelligent forwarding plane. Consequently, content distribution efficiency is reduced due to a lack of inherent multi-path transmission. In Named Data Networking (NDN) instead, routing shall hold a supporting role to forwarding, providing sufficient potential to enhance content dissemination at the forwarding plane. In this paper, we design, implement, and evaluate a novel probability-based forwarding strategy, called Stochastic Adaptive Forwarding (SAF) for NDN. SAF imitates a self-adjusting water pipe system, intelligently guiding and distributing interests through network crossings circumventing link failures and bottlenecks. Just as real pipe systems, SAF employs overpressure valves enabling congested nodes to lower pressure autonomously. Through an implicit feedback mechanism, it is ensured that the fraction of the traffic forwarded via congested nodes decreases. By conducting simulations, we show that our approach outperforms existing forwarding strategies in terms of the interest satisfaction ratio in the majority of the evaluated scenarios. This is achieved by extensive utilization of NDN’s multipath and content-lookup capabilities without relying on the routing plane. SAF explores the local environment by redirecting requests that are likely to be dropped anyway. This enables SAF to identify new paths to the content origin or to cached replicas, circumventing link failures, and resource shortages without relying on routing updates. [ABSTRACT FROM AUTHOR]

A data-centric routing protocol considering a data aggregation technique at relay nodes is required to increase the lifetime of wireless sensor networks. An energy-efficient data-centric routing algorithm is proposed by considering a tradeoff between acquisition time and energy consumption in the wireless sensor network. First, the proposed routing scheme decides the sink node among all sensor nodes in order to minimize the maximum distance between them. Then, the proposed routing extends its tree structure in a way to minimize the link cost between the connected nodes for reducing energy consumption while minimizing the maximum distance between sensor nodes and a sink node for rapid information gathering. Simulation results show that the proposed data-centric routing algorithm has short information acquisition time and low energy consumption; thus, it achieves high energy efficiency in the wireless sensor network compared to conventional routing algorithms. [ABSTRACT FROM AUTHOR]

Network-on-Chip (NoC) research and development have increased noticeably over the past few years. As the NoC size increases, it was an urge to group processing elements (PEs) into clusters, based on common characteristics between these elements or the spatial locality in the floorplan. NoC clustering achieved better performance, scalability, and load balancing. On another hand, many NoC simulators, like NoCTweak, were developed to provide quick and easy tool for early evaluation of NoC-based designs. In this paper, we extend NoCTweak in order to allow it to simulate NoC clustering. The presented NoC clustering simulator supports the modular design technique, which in turn offers the flexibility in configuring cluster parameters. Examples of configurable parameters that are supported by our simulator are adding a cluster manager, adding latency factors of cluster links, and adapting the routing algorithm for both inter-cluster and intra-cluster traffic. [ABSTRACT FROM AUTHOR]

Geographic routing protocol (GRP) allows sensor node to select path solely depending on the position information of its neighbor nodes. However, the irregular distribution of sensor node in wireless sensor networks (WSN) gives rise to the problem that GRP using the greedy algorithm may suffer the problem of local extrema. Due to the routing voids, it tends to result in the failure of data transmission. To overcome this drawback and improve the control packet overhead and transmission delay of routing void, based on virtual coordinate mapping, this paper proposes an efficient void-bypassing routing protocol (EVRP). Through mapping the coordinates on a virtual circle for edge nodes, EVRP transforms the void edge's random structure into a regular one. After clustering and redundant scheduling, each node has an energy threshold. If a node's energy is lower than its threshold, it sends a failure message to its cluster head which then uses the intersection angle with the failure node and considers all its neighbors as preparatory boundary nodes. Each preparatory boundary node is also judged. Thus a virtual rectangle is constructed. Its ability of covering the void which engenders dynamic intermediate destination nodes can enhance the efficiency and success of bypassing routing void. Compared with RGP and GPSR, simulation and analysis results demonstrate that EVRP is superior in finding the shortest routing path with higher delivery ratio, less control packet overhead and energy consumption. [ABSTRACT FROM AUTHOR]

In order to guarantee the QoS of multimedia applications in a mobile ad hoc network (MANET), a reliable packet transmitting mechanism used in MANETs is developed. In this paper, we synthesize the geographical information, bit error rates of the links and 2-hop routing information to elaborate a most durable routing path between the source node and the destination node. In route discovery phase, all the possible paths from the source node to the destination node are checked on the basis of path reliability and number of hops. Meanwhile, 2-hop routing tables are created. Aided by the geographical information, our mechanism can reduce broadcast packets significantly in RREQ phase compared with other flooding-based protocols. The 2-hop routing information is employed just like backup node information used in other stable routing protocols. Once the path breaks, it can be repaired locally and rapidly by setting up a short path to a 2-hop neighboring node. Compared with other four stable mechanisms with excellent performance, our mechanism (B2RP) exhibits a slightly better in terms of packet delivery ratio, average route lifetime and end-to-end delay. [ABSTRACT FROM AUTHOR]

Delay-tolerant networks (DTNs) are an emergent communication paradigm characterized by intermittent connectivity. The nodes in DTNs can take advantage of their contact opportunities to forward messages. However, in noncooperative DTNs, the nodes may be selfish and reluctant to cooperate with each other in message forwarding. In such DTNs, stimulating cooperation among the nodes will be indispensable. Recently, many incentive mechanisms have been proposed to motivate nodes to cooperate in message forwarding. However, most of them cannot guarantee systematic security. To resolve the drawback of the previous incentive mechanisms, we first propose a credit-based rewarding scheme called the earliest path singular rewarding (EPSR) scheme to motivate the nodes to truthfully forward the messages during every contact opportunity. Then, we propose another credit-based rewarding scheme called the earliest path cumulative rewarding (EPCR) scheme by further considering that a node may get more contact information on others. We prove that both the EPSR and EPCR schemes are incentive compatible, and the payment for each delivered message is upper bounded. Furthermore, the proposed schemes can prevent selfish nodes having malicious behaviors. We have conducted real-trace-based simulations to illustrate the effectiveness of the proposed EPSR and EPCR schemes. [ABSTRACT FROM AUTHOR]

Two important challenges in designing a survivable optical network are minimizing backup spectrum allocation and ensuring spectrum assignment constraints. Allocating backup spectrum is one important approach for survivable optical network design. Connection requests which are rejected due to the unavailability of a single backup path can be survived using multiple backup routes. Multiple backup routes not only increase connection acceptance rate, but also improve backup resource sharing. In this paper, we present a strategy for survivability which optimizes primary and backup spectrum allocations and multiple backup route assignments for surviving a connection request. In our strategy, named as Backup Spectrum Reservation with MultiPath Protection (BSR-MPP), multiple backup routes are searched over advance reserved backup resources when an optical connection is concerned. Simulation results show that confinement of backup resources result in higher resource sharing and assignment of multiple backup lightpaths. It can also be observed that BSR-MPP has lower Bandwidth Blocking Probability and higher spectrum efficiency as compared to conventional Shared Path Protection (SPP) and MultiPath Protection (MPP) strategies. [ABSTRACT FROM AUTHOR]

In this paper, we first challenge the accuracy of the so-called innovative assumption that is widely adopted in delay performance analysis of network-coding-based epidemic routing (NCER) in delay-tolerant networks (DTNs). We demonstrate that this optimistic assumption severely underestimates data delivery delay and solves this problem successfully by introducing an extra encounter factor $\delta$. Based on this, we propose a coloring process (CP)-based analytical model to evaluate the delay performance of NCER. Numerical results show that our CP-based method outperforms traditional ordinary differential equation (ODE)-based methods on estimating the delay performance under different network sizes. Furthermore, to mitigate potential competition among multiple data streams from different nodes, we propose a feedback-based recovery protocol (FRP) that takes advantage of finite buffer space and significantly reduces the number of ineffective transmissions between nodes. As a result, FRP can achieve much better delay performance compared with existing protocols in prior work. [ABSTRACT FROM AUTHOR]

Position-based routing is considered to be a very promising routing strategy for communication within vehicular ad hoc networks (VANETs), due to the fact that vehicular nodes can obtain position information from onboard global positioning system receivers and acquire global road layout information from an onboard digital map. Position-based routing protocols, which are based mostly on greedy forwarding, are well-suited to the highly dynamic and rapid-changing network topology of VANETs. In this paper, we outline the background and the latest development in VANETs and survey the state-of-the-art routing protocols previously used in VANETs. We present the pros and cons for each routing protocol, and make a detailed comparison. We also discuss open issues, challenges and future research directions. It is observed that a hybrid routing protocol is the best choice for VANETs in both urban and highway environments. [ABSTRACT FROM AUTHOR]

Several routing schemes have been proposed for intermittently connected wireless mobile networks. The effectiveness of these routing schemes is mostly evaluated using the metrics: messages delivered, message traffic and delay suffered by delivered messages. These metrics provide very limited evaluation of routing schemes. Even very simple and well known attributes like time and space complexity of routing schemes were not measured for evaluating the quality and applicability of routing schemes. Therefore, many significant aspects such as, resource utilization, efficiency in terms of space and time, quality of service parameters and security aspect etc. of routing schemes get overlooked. In this paper, we present the results of experimental evaluation, through simulation, of routing schemes for intermittently connected wireless mobile networks such as Delay Tolerant Network. We evaluated four routing schemes, based on different principles, namely First contact, Epidemic, Spray and wait and Dynamic Social Grouping, on parameters, such as, resource utilization, efficiency, performance and security. We found Spray and wait routing scheme performed better than others, both in terms of resource utilization and efficiency (time and space). [ABSTRACT FROM AUTHOR]

The performance implications of link or node failures in Mobile Ad-hoc Network (MANET) networks are studied in details. Several recovery mechanisms are proposed to reduce the impact of failure and guarantee a loop-free in the network. These mechanisms seek to reduce recovery time, which remains undesirably long in the current routing protocols in wired and wireless networks. Hence, we evaluate the efficiency of the Optimized Link State Routing Protocol with and without recovery paths under varying environment with different node densities. In addition, the mobility of nodes is changing the speed movements when they start to move from area to another one. This paper assists in ascertaining the effect of varying node densities on the connectivity's life between mobile nodes in the network. Hence, it showed the effect of a local recovery mechanism resulted in achieving a significant improvement in network performance by seeking a long life backup path between source and destination for different nodes density. Real time applications are required to be supported by mobile ad hoc networks by finding an efficient recovery mechanism. This is because the MANET networks allow the nodes to move from one area to another without any notification. The real time applications traffics are considered as a sensitive application, and it is the most affected by failure through the occurrence of delay and loss of packets. It is, therefore, not suitable for use by players. In mobile ad hoc networks, routing protocol functions are based on many factors, such as, node mobility and density and broken paths. According to these factors, the paper was further extended to develop a recovery mechanism in MANET based on the mobility and density of nodes to alleviate the impact of the frequent loss of connection due to the flexibility of free nodes, which move from one area to another without pre-notification. The aim behind recovery mechanism is to reduce current recovery time to enhance the Quality of Service in the MANET. [ABSTRACT FROM AUTHOR]

In this paper the improved Congestion Aware Multipath Routing algorithm is analysed in terms of Core network throughput and longer paths contribution. The algorithm discovers unused network resources and dynamically adapts to the actual traffic load and available resources displacement. Several simulation scenarios have been benchmarked in order to verify algorithm in typical Internet Service Provider cases. Simulation scenarios in this paper are focused on verifying functionality in dense core networks. For this purpose, tests were performed on TeraStream based network - the Deutsche Telekom Group design concept. Simulation results have proven better performance and resource utilization of the proposed algorithm than traditional Bellman-Ford based algorithms and equal cost multipath approaches. [ABSTRACT FROM AUTHOR]

The evolution of vehicular network applications, from simple alert message exchange to more elaborate and sophisticated systems, boosts the need for content delivery solutions. A useful technique, in this case, is content replication, in which strategically selected vehicles replicate content and help in the delivery process. However, content replication is particularly challenging in vehicular networks, due to their special characteristics, such as highly dynamic topology, diverse density, and large-scale scenarios. Although there has been progress in routing and dissemination solutions for vehicular networks, few studies have concentrated on the content replication problem. To address this issue, we propose an origin–destination-based content replication (ODCRep) solution that focuses on balancing the number of replicas across the application area. Differently from existing solutions, ODCRep relies only on the origin–destination information and uses computationally efficient algorithms. Results from exhaustive simulations show that ODCRep can achieve high coverage, yet can also consume fewer resources than existing solutions. [ABSTRACT FROM PUBLISHER]

Node clustering is a potential solution to minimize the control signaling overhead of routing protocols in vehicular ad hoc networks (VANETs). High relative vehicle mobility and frequent network topology changes induce instability to node clusters. Node cluster instability inflicts new challenges in maintaining a long route between network nodes, thus increasing the routing overhead. As a result, cluster instability, which is foisted by vehicle mobility, is a crucial issue for cluster-based routing in VANETs. This paper presents a stochastic analysis of the impact of cluster instability on generic routing overhead. A stochastic cluster instability model is adopted to capture the time variations of the cluster structure in terms of the cluster membership change rate and the cluster-overlap state change rate. First, we derive the probability distribution of the intracluster routing overhead using the cluster membership change rate. Second, the intercluster routing overhead is modeled as a rooted tree, with the tree nodes representing the value of the overhead and the tree edges weighted by the probability of a cluster-overlap state change. Numerical results are presented to evaluate the proposed models, which demonstrate a close agreement between analytical and simulation results. [ABSTRACT FROM PUBLISHER]

Successive interference cancelation (SIC) is a new physical-layer technique that enables the receiver to decode composite signals from multiple transmitters sequentially. The introduction of SIC improves the path bandwidth. In this paper, we focus on the design of a bandwidth-aware routing protocol with SIC, aiming at achieving high overall end-to-end throughput. We develop an SICable condition for a routing protocol to identify beneficial SIC opportunities that improve spatial reuse without impacting transmission quality. To further explore the benefits of SIC, we formulate the problem of SIC-aware path bandwidth computation as a linear program and design a distributed heuristic algorithm with polynomial complexity. A routing metric capturing the benefit of SIC in terms of bandwidth and network resource is proposed, by which our routing protocol can choose a path satisfying the bandwidth requirement of the current flow and reserving more network resource for the subsequent ones. Simulation results show that our routing protocol achieves significant gains in network throughput and SIC ratio compared with other routing protocols. [ABSTRACT FROM PUBLISHER]

Vehicular Ad-hoc Networks (VANETs) are seen as the key enabling technology of Intelligent Transportation Systems (ITS). In addition to safety, VANETs also provide a cost-effective platform for numerous comfort and entertainment applications. A pragmatic solution of VANETs requires synergistic efforts in multidisciplinary areas of communication standards, routings, security and trust. Furthermore, a realistic VANET simulator is required for performance evaluation. There have been many research efforts in these areas, and consequently, a number of surveys have been published on various aspects. In this article, we first explain the key characteristics of VANETs, then provide a meta-survey of research works. We take a tutorial approach to introducing VANETs and gradually discuss intricate details. Extensive listings of existing surveys and research projects have been provided to assess development efforts. The article is useful for researchers to look at the big picture and channel their efforts in an effective way. [ABSTRACT FROM AUTHOR]

Geographic routing protocols greatly reduce the requirements of topology storage and provide flexibility in the accommodation of the dynamic behavior of mobile ad hoc networks. This paper presents performance evaluations and comparisons of two geographic routing protocols and the popular AODV protocol. The tradeoffs among the average path reliabilities, average conditional delays, average conditional numbers of hops, and area spectral efficiencies and the effects of various parameters are illustrated for finite ad hoc networks with randomly placed mobiles. This paper uses a dual method of closed-form analysis and simple simulation that is applicable to most routing protocols and provides a much more realistic performance evaluation than has previously been possible. Some features included in the new analysis are shadowing, exclusion and guard zones, distance-dependent fading, and interference correlation. [ABSTRACT FROM PUBLISHER]

We study routing and scheduling algorithms for relay-assisted, multichannel downlink wireless networks [e.g., orthogonal frequency-division multiplexing (OFDM)-based cellular systems with relays]. Over such networks, while it is well understood that the BackPressure algorithm is stabilizing (i.e., queue lengths do not become arbitrarily large), its performance (e.g., delay, buffer usage) can be poor. In this paper, we study an alternative—the MaxWeight algorithm—variants of which are known to have good performance in a single-hop setting. In a general relay setting, however, MaxWeight is not even stabilizing (and thus can have very poor performance). In this paper, we study an iterative MaxWeight algorithm for routing and scheduling in downlink multichannel relay networks. We show that, surprisingly, the iterative MaxWeight algorithm can stabilize the system in several large-scale instantiations of this setting (e.g., general arrivals with full-duplex relays, bounded arrivals with half-duplex relays). Furthermore, using both many-channel large-deviations analysis and simulations, we show that iterative MaxWeight outperforms the BackPressure algorithm from a queue-length/delay perspective. [ABSTRACT FROM AUTHOR]

Today’s ever-growing networks call for routing schemes with sound theoretical scalability guarantees. In this context, a routing scheme is scalable if the amount of memory needed to implement it grows significantly slower than the network size. Unfortunately, theoretical scalability characterizations only exist for shortest path routing, but for general policy routing that current and future networks increasingly rely on, very little understanding is available. In this paper, we attempt to fill this gap. We define a general framework for policy routing, and we study the theoretical scaling properties of three fundamental policy models within this framework. Our most important contributions are the finding that, contrary to shortest path routing, there exist policies that inherently scale well, and a separation between the class of policies that admit compact routing tables and those that do not. Finally, we ask to what extent memory size can be decreased by allowing paths to contain a certain bounded number of policy violations and, surprisingly, we conclude that most unscalable policies remain unscalable under the relaxed model as well. [ABSTRACT FROM AUTHOR]

This paper investigates the rating of network paths, i.e., acquiring quantized measures of path properties such as round-trip time and available bandwidth. Compared to fine-grained measurements, coarse-grained ratings are appealing in that they are not only informative but also cheap to obtain. Motivated by this insight, we first address the scalable acquisition of path ratings by statistical inference. By observing similarities to recommender systems, we examine the applicability of solutions to a recommender system and show that our inference problem can be solved by a class of matrix factorization techniques. A technical contribution is an active and progressive inference framework that not only improves the accuracy by selectively measuring more informative paths, but also speeds up the convergence for available bandwidth by incorporating its measurement methodology. Then, we investigate the usability of rating-based network measurement and inference in applications. A case study is performed on whether locality awareness can be achieved for overlay networks of Pastry and BitTorrent using inferred ratings. We show that such coarse-grained knowledge can improve the performance of peer selection and that finer granularities do not always lead to larger improvements. [ABSTRACT FROM AUTHOR]

Manageability and high availability are critical properties for IP networks. Unfortunately, with link-state routing protocols commonly used in such networks, topological changes lead to transient forwarding loops inducing service disruption. This reduces the frequency at which operators can adapt their network. Prior works proved that it is possible to avoid disruptions due to the planned reconfiguration of a link by progressively changing its weight, leading to a solution that does not require changing protocol specification. In this paper, we study the more general problem of gracefully modifying the logical state of multiple interfaces of a router, while minimizing the number of weight updates. Compared to single-link modifications, the router update problem is k-dimensional for a router having k neighbors. We also show that multidimensional updates may trigger new kinds of disruptions that make the problem more challenging than the single-link case. We then present and evaluate efficient algorithms that compute minimal sequences of weights enabling disruption-free router reconfigurations. Based on analysis of real IP network topologies, we show that both the size of such sequences and the computing time taken by our algorithms are limited. [ABSTRACT FROM AUTHOR]

Mobile wireless sensor networks (MWSNs) consist of many sensor nodes that are randomly distributed in the environment to gather information. In MWSNs the transmission path is affected due to node mobility and node failures. Routing protocols in MWSNs must adjust to topology changes and should determine the path with minimum overheads. Dynamic nature of opportunistic routing strategy is observed to be more suitable for MWSNs. In this paper, a connectivity based energy efficient opportunistic robust (CBEEOR) routing protocol is designed and implemented for MWSNs. CBEEOR design involves algebraic connectivity, prioritized forwarder list for selecting relay node for data forwarding. A back-off time mechanism is implemented to seek cooperation of neighbourhood nodes for forwarding the packets in case the node on the existing path becomes unavailable or fails. This mechanism also ensures coordination among neighbouring nodes. The performance of CBEEOR is compared with both energy efficient opportunistic routing (EEOR) and optimal opportunistic forwarding (OOF), it is observed that CBEEOR fares by 25 and 6 % compared to EEOR and OOF respectively for energy efficiency. CBEEOR also shows better performance for packet delivery, network overheads and end-to-end delay compared to EEOR as well as OOF, making it also suitable for MWSNs with intermittent connectivity. [ABSTRACT FROM AUTHOR]

Geocast routing is one of the most investigated choices for reliable and efficient dissemination of information because of group of vehicles sharing geographic region on the road. Most of geocast routing protocols for intermittently connected Vehicular Adhoc Networks, suffer from low packet delivery, high end-to-end delay and elevated packet loss in intermittently connected networks and low throughput, high hop-to-hop disconnection, larger hop-count in fully connected networks. In this paper, guaranteed geocast routing (GGR) protocol for intermittently connected highway traffic environment has been proposed. GGR utilizes caching and heuristic function for reliable next hop vehicle selection. It also uses FAST (group of neighboring vehicles moving at higher speed than current forwarder) in packet delivery and SLOW (group of neighboring vehicles moving at lower speed than current forwarder) in hop-to-hop failure recovery. One-hop delivery has been guaranteed through acknowledgement. The proposed protocol has been simulated using NS-2 and its performance has been compared with that of adoptive carry-store forward, spray & wait and epidemic routing protocols. Results reveal that the performance of GGR is better in terms of number of routing matrices considered for both intermittently and fully connected networks. [ABSTRACT FROM AUTHOR]

AODV and DSR are normally taken as a standard in reactive routing protocols for Mobile Ad-Hoc Network (MANETs). Both of these protocols are widely used in different applications of MANET because of their simple design and better performance. AODV does not provide optimal results in the scenarios where we have heavy traffic with large number of connections and higher routing load. In this paper, we have introduced a novel idea of 'Reliability Factor' to determine reliable links between the intermediate nodes; based on this factor a reactive routing protocol is proposed, the simulation results of Reliability Factor Based Routing Protocol show that it outperforms AODV and SP-AODV in terms of better packet delivery fraction, routing load and end-to-end delay. [ABSTRACT FROM AUTHOR]

The various applications of Delay Tolerant Networking (DTNs) require a suitable routing protocol for urban environment. In general, the mobile node trajectory is associate with its social relations and regular life in urban areas, and existing DTN routing protocols cannot incorporate in urban environments. This study aims to improve the key targets, such as delivery ratio, latency and network overhead ratio, in urban environments by describing a routing algorithm based on Geographic Grid (GeoGrid). GeoGrid is suitable for a sensory data collection system in which a part of the mobile nodes generate data, and mobile relay nodes transport the data to a fixed sink station. Simulation experiments were carried out to verify the performance of the proposed GeoGrid under an urban scenario, and the results suggest that the GeoGrid outperforms both Epidemic and Prophet routing algorithms in successful delivery ratio, average delivery latency, and network overhead ratio. [ABSTRACT FROM AUTHOR]

Routing in ad hoc networks is challenging as nodes are mobile and links are continuously created and broken. Current on-demand ad hoc routing algorithms start route discovery after path break, incurring high cost to detect the disconnection and to establish a new route. Specifically, when a path is liable to break, the source is warned about the likelihood of disconnection. The source then starts path discovery avoiding disconnection entirely. A path is likely to break when link availability decreases. Since routing is nondeterministic polynomial (NP) hard, this work proposes an improved ad hoc on-demand multipath distance vector (AOMDV) based on link availability, neighboring node's queuing delay, node mobility, and bit error rate. The optimal path is selected using BAT meta-heuristic optimization. Simulation shows improved performance compared to AOMDV. [ABSTRACT FROM AUTHOR]

Border Gateway Protocol (BGP) is vulnerable to routing attacks because of the lack of inherent verification mechanism. Several secure BGP schemes have been proposed to prevent routing attacks by leveraging cryptographic verification of BGP routing updates. In this paper, we present a new type of attacks, called TIGER, which aims to invalidate the “proven” security of these secure BGP schemes and allow ASes to announce forged routes even under full deployment of any existing secure BGP proposal. By launching TIGER attacks, malicious ASes can easily generate and announce forged routes which can be successfully verified by the existing secure BGP schemes. Furthermore, TIGER attacks can evade existing routing anomaly detection schemes by guaranteeing routing data-plane availability and consistency of control- and data-plane. Toward a new securing BGP scheme, we propose Anti-TIGER to detect and defend against TIGER attacks. Anti-TIGER enables robust TIGER detection by collaborations between ASes. In particular, we leverage Spread Spectrum Communication technique to watermark certain special probing packets, which manifest the existence of TIGER attacks. Anti-TIGER does not require any modifications in routing data-plane, therefore it is easy to deploy and incrementally deployable. We evaluate the effectiveness of TIGER and Anti-TIGER by experiments with real AS topologies of the Internet. Our experiment results show that TIGER attacks can successfully hijack a considerable number of prefixes. In the meanwhile, Anti-TIGER can achieve 100 percent detection ratio of TIGER attacks. [ABSTRACT FROM PUBLISHER]

Mobile Ad hoc network is a self organized, self maintained network. Node movement is the important factor of increasing the control overhead in the network. The main objective of the paper is to reduce the control overhead by using the domination set based routing. The nodes which use to connect all the other nodes in the network are called dominating nodes, and the set of dominating nodes forms domination set. This paper proposes a new approach for finding the route and reducing the reroute establishment delay and increasing the packet delivery ratio. The efficiency of the method is demonstrated through simulation study. [ABSTRACT FROM AUTHOR]