Showing papers on "Equal-cost multi-path routing published in 2016"

Spatial Reusability-Aware Routing in Multi-Hop Wireless Networks

Abstract: In the problem of routing in multi-hop wireless networks, to achieve high end-to-end throughput, it is crucial to find the “best” path from the source node to the destination node. Although a large number of routing protocols have been proposed to find the path with minimum total transmission count/time for delivering a single packet, such transmission count/time minimizing protocols cannot be guaranteed to achieve maximum end-to-end throughput. In this paper, we argue that by carefully considering spatial reusability of the wireless communication media, we can tremendously improve the end-to-end throughput in multi-hop wireless networks. To support our argument, we propose spatial reusability-aware single-path routing (SASR) and anypath routing (SAAR) protocols, and compare them with existing single-path routing and anypath routing protocols, respectively. Our evaluation results show that our protocols significantly improve the end-to-end throughput compared with existing protocols. Specifically, for single-path routing, the median throughput gain is up to 60 percent, and for each source-destination pair, the throughput gain is as high as $5.3\times$ ; for anypath routing, the maximum per-flow throughput gain is 71.6 percent, while the median gain is up to 13.2 percent.

An improved harmony search based energy-efficient routing algorithm for wireless sensor networks

Abstract: Graphical abstractDisplay Omitted HighlightsA new encoding of harmony memory for routing in WSNs has been proposed.A new generation method of a new harmony for routing in WSNs has been proposed.The dynamic adaptation is introduced for the parameter HMCR to improve the performance of the proposed routing algorithm.An effective local search strategy is proposed to improve the convergence speed and the accuracy of the proposed routing algorithm.An energy efficient objective function model is proposed. Wireless sensor networks (WSNs) is one of the most important technologies in this century. As sensor nodes have limited energy resources, designing energy-efficient routing algorithms for WSNs has become the research focus. And because WSNs routing for maximizing the network lifetime is a NP-hard problem, many researchers try to optimize it with meta-heuristics. However, due to the uncertain variable number and strong constraints of WSNs routing problem, most meta-heuristics are inappropriate in designing routing algorithms for WSNs. This paper proposes an Improved Harmony Search Based Energy Efficient Routing Algorithm (IHSBEER) for WSNs, which is based on harmony search (HS) algorithm (a meta-heuristic). To address the WSNs routing problem with HS algorithm, several key improvements have been put forward: First of all, the encoding of harmony memory has been improved based on the characteristics of routing in WSNs. Secondly, the improvisation of a new harmony has also been improved. We have introduced dynamic adaptation for the parameter HMCR to avoid the prematurity in early generations and strengthen its local search ability in late generations. Meanwhile, the adjustment process of HS algorithm has been discarded to make the proposed routing algorithm containing less parameters. Thirdly, an effective local search strategy is proposed to enhance the local search ability, so as to improve the convergence speed and the accuracy of routing algorithm. In addition, an objective function model that considers both the energy consumption and the length of path is developed. The detailed descriptions and performance test results of the proposed approach are included. The experimental results clearly show the advantages of the proposed routing algorithm for WSNs.

Energy Efficient Direction-Based PDORP Routing Protocol for WSN

Abstract: Energy consumption is one of the constraints in wireless sensor networks (WSNs). The routing protocols are the hot areas to address quality-of-service (QoS) related issues, viz., energy consumption, network lifetime, network scalability, and packet overhead. The key issue in WSN is that these networks suffer from the packet overhead, which is the root cause of more energy consumption and degrade the QoS in sensor networks. In WSN, there are several routing protocols, which are used to enhance the performance of the network. Out of those protocols, dynamic source routing (DSR) protocol is more suitable in terms of small energy density, but sometimes when the mode of a node changes from active to sleep, the efficiency decreases as the data packets need to wait at the initial point, where the packet has been sent and this increases the waiting time and end-to-end delay of the packets, which leads to increase in energy consumption. Our problem is to identify the dead nodes and to choose another suitable path so that the data transmission becomes smoother and less energy gets conserved. In order to resolve these issues, we propose directional transmission-based energy aware routing protocol named PDORP. The proposed protocol PDORP has the characteristics of both power efficient gathering sensor information system and DSR routing protocols. In addition, hybridization of genetic algorithm and bacterial foraging optimization is applied to proposed routing protocol to identify energy efficient optimal paths. The performance analysis, comparison through a hybridization approach of the proposed routing protocol, gives better result comprising less bit error rate, less delay, less energy consumption, and better throughput, which leads to better QoS and prolong the lifetime of the network. Moreover, the computation model is adopted to evaluate and compare the performance of the both routing protocols using soft computing techniques.

An Energy-Efficient Region-Based RPL Routing Protocol for Low-Power and Lossy Networks

Abstract: Routing plays an important role in the overall architecture of the Internet of Things. IETF has standardized the RPL routing protocol to provide the interoperability for low-power and lossy networks (LLNs). LLNs cover a wide scope of applications, such as building automation, industrial control, healthcare, and so on. LLNs applications require reliable and energy-efficient routing support. Point-to-point (P2P) communication is a fundamental requirement of many LLNs applications. However, traditional routing protocols usually propagate throughout the whole network to discover a reliable P2P route, which requires large amount energy consumption. Again, it is challenging to achieve both reliability and energy-efficiency simultaneously, especially for LLNs. In this paper, we propose a novel energy-efficient region-based routing protocol (ER-RPL), which achieves energy-efficient data delivery without compromising reliability. In contrast of traditional routing protocols where all nodes are required for route discovery, the proposed scheme only requires a subset of nodes to do the job, which is the key of energy saving. Our theoretical analysis and extensive simulation studies demonstrate that ER-RPL has a great performance superiority over two conventional benchmark protocols, i.e., RPL and P2P-RPL.

An ant colony optimization based routing algorithm for extending network lifetime in wireless sensor networks

Abstract: Reducing the energy consumption of network nodes is one of the most important problems for routing in wireless sensor networks because of the battery limitation in each sensor. This paper presents a new ant colony optimization based routing algorithm that uses special parameters in its competency function for reducing energy consumption of network nodes. In this new proposed algorithm called life time aware routing algorithm for wireless sensor networks (LTAWSN), a new pheromone update operator was designed to integrate energy consumption and hops into routing choice. Finally, with the results of the multiple simulations we were able to show that LTAWSN, in comparison with the previous ant colony based routing algorithm, energy aware ant colony routing algorithms for the routing of wireless sensor networks, ant colony optimization-based location-aware routing algorithm for wireless sensor networks and traditional ant colony algorithm, increase the efficiency of the system, obtains more balanced transmission among the nodes and reduce the energy consumption of the routing and extends the network lifetime.

A performance comparison of delay-tolerant network routing protocols

Abstract: Networks that lack continuous end-to-end connections among their nodes due to node mobility, constrained power sources, or limited data storage space are called DTNs. To overcome the intermittent connectivity, DTN nodes store and carry the data packets they receive until they come into communication range of each other. In addition, they spread multiple copies of the same packet on the network to increase the delivery probability. In recent years, several routing protocols have been developed specifically for DTNs. These protocols vary in the number of copies they spread and the information they use to guide the packets to their destinations. There have been some reviews of those protocols, but no performance comparison has been conducted. In this article, we study four well-known DTN routing protocols: EPIDEMIC, Spray-and-Wait, PROPHET, and MAXPROP. We introduce a procedural form to present the protocols. We measure the performance of the protocols in terms of packet delivery, delivery cost, and average packet delay. We compare the protocols' performance together with the results of optimal routing using real-life scenarios of vehicles and pedestrians roaming in a city. We conduct several simulation experiments to show the impact of changing buffer capacity, packet lifetime, packet generation rate, and number of nodes on the performance metrics. The article is concluded by providing guidelines to develop an efficient DTN routing protocol. To the best of our knowledge, this work is the first to provide a detailed performance comparison among the diverse collection of DTN routing protocols.

Defence against Black Hole and Selective Forwarding Attacks for Medical WSNs in the IoT.

Abstract: Wireless sensor networks (WSNs) are being used to facilitate monitoring of patients in hospital and home environments. These systems consist of a variety of different components/sensors and many processes like clustering, routing, security, and self-organization. Routing is necessary for medical-based WSNs because it allows remote data delivery and it facilitates network scalability in large hospitals. However, routing entails several problems, mainly due to the open nature of wireless networks, and these need to be addressed. This paper looks at two of the problems that arise due to wireless routing between the nodes and access points of a medical WSN (for IoT use): black hole and selective forwarding (SF) attacks. A solution to the former can readily be provided through the use of cryptographic hashes, while the latter makes use of a neighbourhood watch and threshold-based analysis to detect and correct SF attacks. The scheme proposed here is capable of detecting a selective forwarding attack with over 96% accuracy and successfully identifying the malicious node with 83% accuracy.

An experimental investigation of hyperbolic routing with a smart forwarding plane in NDN

Abstract: Routing in NDN networks must scale in terms of forwarding table size and routing protocol overhead. Hyperbolic routing (HR) presents a potential solution to address the routing scalability problem, because it does not use traditional forwarding tables or exchange routing updates upon changes in network topologies. Although HR has the drawbacks of producing sub-optimal routes or local minima for some destinations, these issues can be mitigated by NDN's intelligent data forwarding plane. However, HR's viability still depends on both the quality of the routes HR provides and the overhead incurred at the forwarding plane due to HR's sub-optimal behavior. We designed a new forwarding strategy called Adaptive Smoothed RTT-based Forwarding (ASF) to mitigate HR's sub-optimal path selection. This paper describes our experimental investigation into the packet delivery delay and overhead under HR as compared with Named-Data Link State Routing (NLSR), which calculates shortest paths. We run emulation experiments using various topologies with different failure scenarios, probing intervals, and maximum number of next hops for a name prefix. Our results show that HR's delay stretch has a median close to 1 and a 95th-percentile around or below 2, which does not grow with the network size. HR's message overhead in dynamic topologies is nearly independent of the network size, while NLSR's overhead grows polynomially at least. These results suggest that HR offers a more scalable routing solution with little impact on the optimality of routing paths.

A Predictive Cross-Layered Interference Management in a Multichannel MAC with Reactive Routing in VANET

Abstract: Vehicular ad hoc networks (VANETs) represent a particular mobile technology that permits communication between vehicles, offering security and comfort. Nowadays, distributed mobile wireless computing is becoming a very important communication paradigm, due to its flexibility to adapt to different mobile applications. In this work, an interference aware metric is proposed in order to reduce the level of interference between each pair of nodes at the MAC and routing layer. In particular, this metric with a prediction algorithm is proposed to work in a cross-layered MAC and an on-demand routing scheme in multi-radio vehicular networks, wherein each node is equipped with two multi-channel radio interfaces. The proposed metric is based on the maximization of the average signal-to-interference ratio (SIR) level of the connection between source and destination. In order to relieve the effects of the co-channel interference perceived by mobile nodes, transmission channels are switched on a basis of a periodical SIR evaluation. Our solution has been integrated with an on-demand routing scheme but it can be applied to other routing strategies. Three on-demand interference aware routing schemes integrating IEEE 802.11p Multi-channel MAC have been tested to assess the benefits of the novel metric applied to a vehicular context. NS-3 has been used for implementing and testing the proposed idea, and significant performance improvements were obtained: in particular, the proposed policy has resulted in an enhancement of network performance in terms of throughput and packet delivery ratio.

A Street-Centric Routing Protocol Based on Microtopology in Vehicular Ad Hoc Networks

Abstract: In a vehicular ad hoc network (VANET), high mobility and uneven distribution of vehicles are important factors affecting the performance of routing protocols. The high mobility may cause frequent changes of network topology, whereas the uneven distribution of vehicles may lead to routing failures due to network partition; even high density of vehicles may cause severe wireless channel contentions in an urban environment. In this paper, we propose a novel concept called the microtopology (MT), which consists of vehicles and wireless links among vehicles along a street as a basic component of routing paths and even the entire network topology. We abstract the MT model reflecting the dynamic routing-related characteristics in practical urban scenarios along streets, including the effect of mobility of vehicles, signal fading, wireless channel contention, and existing data traffic. We first analyze the endside-to-endside routing performance in an MT as a basis of routing decision. Then, we propose a novel street-centric routing protocol based on MT (SRPMT) along the streets for VANETs. Simulation results show that our proposed SRPMT protocol achieves higher data delivery rate and shorter average end-to-end delay compared with the performance of greedy perimeter stateless routing (GPSR) and greedy traffic-aware routing (GyTAR).

SDN Partitioning: A Centralized Control Plane for Distributed Routing Protocols

Abstract: Hybrid IP networks that use both control paradigms - distributed and centralized - promise the best of two worlds: programmability and agility of SDN, and reliability and fault tolerance of distributed routing protocols like OSPF. The common approaches follow a division of labor concept, where SDN controls prioritized traffic and OSPF assures care-free operation of best effort traffic. We propose SDN Partitioning, which establishes centralized control over the distributed routing protocol by partitioning the topology into sub-domains with SDN-enabled border nodes, such that OSPF's routing updates have to traverse SDN border nodes to reach neighboring sub-domains. This allows the central controller to modify how sub-domains view one another, which in turn allows to steer inter-sub-domain traffic. The degree of dynamic control against simplicity of OSPF can be trade off by adjusting the size of the sub-domains. This paper explains the technical requirements, presents a novel scheme for balanced topology partitioning, and provides the models for common network management tasks. Our performance evaluation shows that - already in its minimum configuration with two sub-domains - SDN Partitioning provides significant improvements in all respects compared to legacy routing protocols, whereas smaller sub-domains provide network control capabilities comparable to full SDN deployment.

Optimizing restoration with segment routing

Abstract: Segment routing is a new proposed routing mechanism for simplified and flexible path control in IP/MPLS networks. It builds on existing network routing and connection management protocols and one of its important features is the automatic rerouting of connections upon failure. Re-routing can be done with available restoration mechanisms including IGP-based rerouting and fast reroute with loop-free alternates. This is particularly attractive for use in Software Defined Networks (SDN) because the central controller need only be involved at connection set-up time and failures are handled automatically in a distributed manner. A significant challenge in restoration optimization in segment routed networks is the centralized determination of connections primary paths so as to enable the best sharing of restoration bandwidth over non-simultaneous network failures. We formulate this problem as a linear programming problem and develop an efficient primal-dual algorithm for the solution. We also develop a simple randomized rounding scheme for cases when there are additional constraints on segment routing. We demonstrate the significant capacity benefits achievable from this optimized restoration with segment routing.

GCA:Global Congestion Awareness for Load Balance in Networks-on-Chip

Abstract: As modern CMPs scale to ever increasing core counts, Networks-on-Chip (NoCs) are emerging as an interconnection fabric, enabling communication between components. While NoCs provide high and scalable bandwidth, current routing algorithms, such as dimension-ordered routing, suffer from poor load balance, leading to reduced throughput and high latencies. Improving load balance, hence, is critical in future CMP designs where increased latency leads to wasted power and energy waiting for outstanding requests to resolve. Adaptive routing is a known technique to improve load balance, however, prior adaptive routing techniques either use local or regionally-aggregated information to form their routing decisions. This paper proposes a new, light-weight, adaptive routing algorithm for on-chip routers based on global link state and congestion information, Global Congestion Awareness (GCA). GCA uses a simple, low-complexity route calculation unit, to calculate paths to their destination without the myopia of local decisions, nor the aggregation of unrelated status information, found in prior designs. In particular GCA outperforms local adaptive routing by 26 percent, Regional Congestion Awareness (RCA) by 15 percent, and a recent competing adaptive routing algorithm, DAR, by 8 percent on average on realistic workloads.

SCMon: Leveraging segment routing to improve network monitoring

Abstract: To guarantee correct operation of their networks, operators have to promptly detect and diagnose data-plane issues, like broken interface cards or link failures. Networks are becoming more complex, with a growing number of Equal Cost MultiPath (ECMP) and link bundles. Hence, some data-plane problems (e.g. silent packet dropping at one router) can hardly be detected with control-plane protocols or simple monitoring tools like ping or traceroute. In this paper, we propose a new technique, called SCMon, that enables continuous monitoring of the data-plane, in order to track the health of all routers and links. SCMon leverages the recently proposed Segment Routing (SR) architecture to monitor the entire network with a single box (and no additional monitoring protocol). In particular, SCMon uses SR to (i) force monitoring probes to travel over cycles; and (ii) test parallel links and bundles at a per-link granularity. We present original algorithms to compute cycles that cover all network links with a limited number of SR segments. Further, we prototype and evaluate SCMon both with simulations and Linux-based emulations. Our experiments show that SCMon quickly detects and precisely pinpoints data-plane problems, with a limited overhead.

Logical router with multiple routing components

Abstract: Some embodiments provide a method for implementing a logical router in a network. The method receives a definition of a logical router for implementation on a set of network elements. The method defines several routing components for the logical router. Each of the defined routing components includes a separate set of routes and separate set of logical interfaces. The method implements the several routing components in the network. In some embodiments, the several routing components include one distributed routing component and several centralized routing components.

PIS: A Multi-Dimensional Routing Protocol for Socially-Aware Networking

Abstract: Socially-aware networking is an emerging paradigm for intermittently connected networks consisting of mobile users with social relationships and characteristics. In this setting, humans are the main carriers of mobile devices. Hence, their connections, social features, and behaviors can be exploited to improve the performance of data forwarding protocols. In this paper, we first explore the impact of three social features, namely physical proximity, user interests, and social relationship on users’ daily routines. Then, we propose a multi-dimensional routing protocol called Proximity-Interest-Social (PIS) protocol in which the three different social dimensions are integrated into a unified distance function in order to select optimal intermediate data carriers. PIS protocol utilizes a time slot management mechanism to discover users’ movement similarities in different time periods during a day. We compare the performance of PIS to Epidemic, PROPHET, and SimBet routing protocols using SIGCOMM09 and INFOCOM06 data sets. The experiment results show that PIS outperforms other benchmark routing protocols with the highest data delivery ratio with a low communication overhead.

A Resilient Routing Algorithm with Formal Reliability Analysis for Partially Connected 3D-NoCs

Abstract: 3D ICs can take advantage of a scalable communication platform, commonly referred to as the Networks-on-Chip (NoC). In the basic form of 3D-NoC, all routers are vertically connected. Partially connected 3D-NoC has emerged because of physical limitations of using vertical links. Routing is of great importance in such partially connected architectures. A high-performance, fault-tolerant and adaptive routing strategy with respect to the communication flow among the cores is crucial while freedom from livelock and deadlock has to be guaranteed. In this paper we introduce a new routing algorithm for partially connected 3D-NoCs. The routing algorithm is adaptive and tolerates the faults on vertical links as compared to the predesigned routing algorithms. Our results show a $40-50\%$ improvement in the fraction of intact inter-level communications when the fault tolerant algorithm is used. This routing algorithm is light-weight and has only one virtual channel along the $Y$ dimension.

Fault-Tolerant Networks-on-Chip Routing With Coarse and Fine-Grained Look-Ahead

Abstract: Fault tolerance and adaptive capabilities are challenges for modern networks-on-chip (NoC) due to the increase in physical defects in advanced manufacturing processes. Two novel adaptive routing algorithms, namely coarse and fine-grained (FG) look-ahead algorithms, are proposed in this paper to enhance 2-D mesh/torus NoC system fault-tolerant capabilities. These strategies use fault flag codes from neighboring nodes to obtain the status or conditions of real-time traffic in an NoC region, then calculate the path weights and choose the route to forward packets. This approach enables the router to minimize congestion for the adjacent connected channels and also to bypass a path with faulty channels by looking ahead at distant neighboring router paths. The novelty of the proposed routing algorithms is the weighted path selection strategies, which make near-optimal routing decisions to maintain the NoC system performance under high fault rates. Results show that the proposed routing algorithms can achieve performance improvement compared to other state of the art works under various traffic loads and high fault rates. The routing algorithm with FG look-ahead capability achieves a higher throughput compared with the coarse-grained approach under complex fault patterns. The hardware area/power overheads of both routing approaches are relatively low which does not prohibit scalability for large-scale NoC implementations.

Contact expectation based routing for delay tolerant networks

Abstract: In conventional networks, routing problem can be modeled as the design of an efficient source-to-destination route based on persistent end-to-end paths. However, in a delay tolerant network (DTN), nodes are intermittently connected and thus, the end-to-end paths will not always exist, in which routing is a challenging issue. Previous DTN routing protocols tend to make routing decision based on the nodes' contact information. In this paper, we observe that considering both the nodes' contact information and message property such as the time-to-live (TTL) would help to improve the performance. Embedded this idea, we first propose an expected encounter based routing protocol (EER) which distributes multiple replicas of a message proportionally between two encounters according to their expected encounter values. In case of a single replica of a message, EER makes the routing decision by comparing two encountering nodes' minimum expected meeting delays to destination. We further propose a community aware routing protocol (CAR) which takes advantages of the high contact frequency property of the nodes within the same community. We also propose the buffer management strategies corresponding for the two protocols. We conduct simulations to evaluate our proposed protocols and some existing ones on three metrics: delivery ratio, latency and goodput. The simulation results illustrate that our proposed EER and CAR protocols outperform other existing ones.

Time-shifted multilayer graph: A routing framework for bulk data transfer in optical circuit-switched networks with assistive storage

Abstract: Increasing bulk data transfers incur peak-hour bandwidth contention between bulky and short flows as well as between bulky flows. To mitigate this contention, storage is introduced into the forwarding path so that bulk data that are delay tolerant can be temporarily stored and forwarded at a later time. However, the storage introduces an additional complexity into the conventional routing process. What was a spatial resource allocation problem becomes a scheduling problem, in which both bandwidth and storage constraints must be considered and both spatial assignments and temporal arrangements must be performed. In this paper, we propose a routing framework for bulk data transfer in optical circuit-switched networks with assistive storage. This framework is based on a multilayer graph built from a set of snapshots (i.e., layers) of the dynamics in a network. By performing shortest path routing on the multilayer graph, "end-to-end" paths over time and space are found for requests, thus greatly simplifying the provisioning process. We study how the number of layers used for routing affects the network blocking performance and how traffic characteristics and link capacity affect the number of layers. We find that the majority of requests can be served with only one additional layer. A trade-off between computational complexity and blocking performance can be reached by limiting the number of layers used for routing. In our simulations, the request blocking probability is reduced from 13.5% to 0.9% by limiting routing to 11 layers. Request blocking is avoided when routing is allowed within 29 layers.

An Opportunistic Void Avoidance Routing Protocol for Underwater Sensor Networks

Abstract: An Underwater Sensor Network (UWSN) has many unique features that makes it different from terrestrial network. This includes lower bandwidth, longer propagation delay, dynamic topology, high error rate, and energy constraint. To overcome the limitations of such an environment, opportunistic routing has recently attracted much attention due to its ability to improve the performance of UWSNs in terms of packet delivery ratio and energy saving. With the aid of opportunistic data routing, underwater sensors can collaboratively route a packet towards the destination which is a more adequate approach for sparse and lossy channels. In this paper, we propose a new routing protocol, called Opportunistic Void Avoidance Routing (OVAR), to address the void problem and high bit error rate without relying on any positioning system. OVAR is able to efficiently bypass all kinds of void areas with the lowest possible cost (including energy and delay) while prioritising the group of candidate nodes with the highest packet advancement. Given the density of neighbours (sparse or dense), each forwarding node is able to hold a trade-off between packet advancement and energy consumption by adjusting the number of nodes in its forwarding set. OVAR is also able to select the forwarding set in any direction from the sender without including any hidden node. The results of our extensive simulation study show that OVAR outperforms other protocols in terms of packet delivery ratio, energy consumption, and average end-to-end delay.