Showing papers on "Link-state routing protocol published in 2020"

A hybrid secure routing and monitoring mechanism in IoT-based wireless sensor networks

Abstract: Internet of Things (IoT) has advanced its pervasiveness across the globe for the development of smart networks. It is aimed to deploy network edge that enables smart services and computation for the IoT devices. In addition, this deployment would not only improve the user experience but also provide service resiliency in case of any catastrophes. In IoT applications, the edge computing exploits distributed architecture and closeness of end-users to provide faster response and better quality of service. However, the security concern is majorly addressed to resist the vulnerability of attacks (VoA). Existing methodologies deal only with static wireless sensor web to deduce the intrusions in which the sensor nodes are deployed in a uniform manner to retain the constancy. Since the sensor nodes are constantly being in question through different transmission regions with several levels of velocities, selection of sensor monitoring nodes or guard nodes has become a challenging job in recent research. In addition, the adversaries are also moving from one location to another to explore its specific chores around the network. Thus, to provide flexible security, we propose a secure routing and monitoring protocol with multi-variant tuples using Two-Fish (TF) symmetric key approach to discover and prevent the adversaries in the global sensor network. The proposed approach is designed on the basis of the Authentication and Encryption Model (ATE). Using Eligibility Weight Function (EWF), the sensor guard nodes are selected and it is hidden with the help of complex symmetric key approach. A secure hybrid routing protocol is chosen to be built by inheriting the properties of both Multipath Optimized Link State Routing (OLSR) and Ad hoc On-Demand Multipath Distance Vector (AOMDV) protocols. The result of the proposed approach is shown that it has a high percentage of monitoring nodes in comparison with the existing routing schemes. Moreover, the proposed routing mechanism is resilient to multiple mobile adversaries; and hence it ensures multipath delivery.

Performance Analysis of Routing Protocols for UAV Communication Networks

Abstract: The design of routing protocol is an important and key problem in unmanned aerial vehicle (UAV) communication networks. In low altitude environment, UAV information transmission is a complex task. It is an important scientific challenge to design a routing protocol that can provide efficient and reliable node to node packet transmission. This paper develops a more realistic simulation environment based on OPNET 14.5, and performs performance tests and comparisons on four classic routing protocols: Ad Hoc on demand distance vector (AODV), dynamic source routing (DSR), optimized link state routing (OLSR), and geographic routing protocol (GRP). The performance parameters such as network delay, traffic received, data dropped and throughput are compared and analyzed. The experimental results indicate that different routing protocols can be adapted to different UAV communication network scenarios. Therefore, the quantitative results can provide pertinent reference for choosing the best routing protocol in different scenarios.

MCLMR: A Multicriteria Based Multipath Routing in the Mobile Ad Hoc Networks

Abstract: In Mobile Ad hoc Networks (MANETs), nodes’ mobility, traffic congestion, and link quality estimation of the intermediate nodes are very crucial factors for establishing a reliable forwarding path between a source and destination node pairs. The unpredictable movement of nodes and random data traffic flow at a single node can cause congestion and network topology instability, which significantly lowers the performance of the ad hoc network. Indeed, the above-highlighted issues can be mitigated by implementing a more reliable mobility-centric, contention, and link quality-aware routing protocol for efficient data transmissions in a mobile network. This paper proposes a routing strategy called Mobility, Contention window, and Link quality sensitive multipath Routing (MCLMR) in MANETs, which considers the nodes mobility, contention window size, and link quality estimated value of the intermediate nodes in the optimal route selection. Also, Technique for Order of Preference by Similarity to Ideal Solution; a multicriteria decision-making technique, which provides weights according to node mobility, contention window size, and link quality estimated values, is also employed for the selection of intermediate nodes, whereas the Expected Number of Transmissions metric is used to minimize the effect of control message storm. The extensive simulations results prove that the proposed MCLMR routing scheme outperforms the conventional Multipath Optimized Link State Routing (MP-OLSR) and MP-OLSRv2 routing schemes in terms of network throughput, end-to-end delay, energy consumption, and packets loss ratio.

Link State Aware Dynamic Routing and Spectrum Allocation Strategy in Elastic Optical Networks

Abstract: Compared with traditional wavelength division optical network, elastic optical network (EON) divides the network spectrum into smaller spectrum slots to improve the spectrum utilization, but the high-quality spectrum division also complicates the routing and spectrum allocation (RSA) problem. Various strategies are proposed for reducing the RSA complexity and improving system traffic bearing capacity. However, previous RSA strategies do not consider the changing physical layer impairments that will also impact signal quality and even lead to violation of quality of transmission (QoT), the data cannot be transmitted correctly if the link state is degraded. Therefore, cross-layer optimization is desired, which means that different layer information is taken into account in the RSA strategy. In this paper, we propose a new link state-aware (LSA) RSA strategy to guarantee the QoT requirements under different link states. At first, the link state is evaluated based on chromatic dispersion (CD) and optical signal-to-noise ratio (OSNR), and a LightGBM model is exploited for CD and OSNR estimation. In LSA-RSA strategy, the link state is considered as a metric for qualified routing paths finding, and the link capacity is calculated based on the link state and used in spectrum allocation. Simulation results show that the average CD and OSNR estimation errors of the LightGBM model are 0.28ps/nm and 0.68dB, respectively. Under different link states and traffic loads, the LSA-RSA strategy can reduce traffic failure probability by more than 20%, and traffic load can increase 40Erlang when the bandwidth blocking probability equals 10%.

Multipoint Relaying Versus Chain-Branch-Leaf Clustering Performance in Optimized Link State Routing-Based Vehicular Ad Hoc Networks

Abstract: Routing protocols for vehicular ad hoc networks resort to clustering in order to optimize network performance. Concerning the optimized link state routing protocol and the plethora of its derivatives, the multipoint relaying (MPR) technique has proven its efficiency as an accurate clustering scheme over the last two decades. However, it has been emphasized recently that the MPR technique, which was originally designed for open areas, does not benefit from the particular configuration of road sections, which are intrinsically spatially constrained. A clustering scheme exploiting this particularity, namely chain-branch-leaf (CBL), has been introduced in order to enhance the flooding of broadcast traffic, including that related to routing operations. In this paper, both MPR and CBL are evaluated through MATLAB simulation over several scenarios based on realistic road configurations and traffic generated with SUMO simulator. The results show that CBL actually reduces the number of nodes acting as relays (cluster-heads) in the network, thus decreasing the routing traffic related to creation and retransmission of topology control messages. Also, they show that, with CBL, the nodes chosen as relays remain longer in this role, thus favoring the overall network stability, and that most of the nodes remain attached longer to the same relay than with the MPR technique.

Beamforming-Constrained Swarm UAS Networking Routing

Abstract: With the evolution of 5G cellular communication, beamforming is mature for the implementation on a large scale. The development of cellular networking provides a great opportunity for swarm UAS. Concurrently, the advantages of swarm UAS can provide immense improvement to the advance of industrial and residential implementations.However, the nature of the antenna array constrains beam-forming in a limited space which is rarely mentioned in networking routing researches. In this paper, regarding the constrained steering space, we proposed a novel algorithm,Optimized Ad-hoc On-demand Distance Vector (OAODV),which aims to improve the capacity of beamforming on swarm UAS networking. With the adjustable searching space, OAODV can achieve better latency, overhead, and link generation than the conventional algorithms of Ad-hoc On-demand Distance Vector (AODV) and Optimized Link State Routing (OLSR). Compared with AODV and OLSR, OAODV can reduce 35.07% and 68.93%of average overhead, and decrease 47.73% and 11.55%of average latency respectively. Further, we leverage Ant Colony Optimization(ACO) to enhance OAODV, and the ACO enabled OAODV can achieve better throughput and fewer hops with reduction of overhead. The proposed algorithms show the promising capacity to improve swarm UAS networking.

Routing With Traffic Awareness and Link Preference in Internet of Vehicles

Abstract: Considering the high mobility and uneven distribution of vehicles, an efficient routing protocol should avoid that the sent packets are forwarded within road segments with ultra-low density or serious data congestion in vehicular networks. To this end, in this paper, we propose a Traffic aware and Link Quality sensitive Routing Protocol (TLRP) for urban Internet of Vehicles (IoV). First, we design a novel routing metric, i.e., Link Transmission Quality (LTQ), to account for the impact of the number, quality and relative positions of communication links along a routing path on the network performance. Then, to adapt to the dynamic characteristics of IoV, a road weight evaluation scheme is presented to assess each road segment using the real-time traffic and link information quantified by the LTQ. Next, the path with the lowest aggregated weight is selected as the routing candidate. Extensive simulations demonstrate that our proposed protocol achieves significant performance improvements compared to the state-of-the-art protocol MM-GPSR, the typical junction-based scheme E-GyTAR, and the classic connectivity-based routing iCAR, in terms of packet delivery ratio and average transmission delay.

Performance Optimization of MANET Networks through Routing Protocol Analysis

Abstract: A Mobile Ad Hoc Network (MANET) protocol requires proper settings to perform data transmission optimally. To overcome this problem, it is necessary to select the correct routing protocol and use the routing protocol’s default parameter values. This study examined the effect of route request parameters, such as RREQ_RETRIES and MAX_RREQ_TIMOUT, on the Ad Hoc On-demand Distance Vector (AODV) protocol, which was then compared with the default AODV performance Optimized Link State Routing (OLSR) protocols. The performance metrics used for measuring performance were Packet Delivery Ratio (PDR), throughput, delay, packet loss, energy consumption, and routing overhead. The results show that the OLSR protocol has a smaller delay than the AODV protocol, while in other measurements, the AODV protocol is better than OLSR. By reducing the combination value of RREQ_RETRIES, MAX_RREQ_TIMEOUT in AODV routing to (2, 10 s) and (3, 5 s), the protocol’s performance can be improved. The two combinations result in an average increase in throughput performance of 3.09%, a decrease in delay of 17.7%, a decrease in packet loss of 27.15%, and an increase in PDR of 4.8%. For variations in the speed of movement of nodes, 20 m/s has the best performance, while 5 m/s has the worst performance.

Performance Analysis of Routing Protocols AODV, OLSR and DSDV on MANET using NS3

Abstract: Wireless Sensor Networks (WSN) have been widely used to process the monitoring of earth physical phenomena remotely. The result of data sensing in a certain area is transmitting to the server by routing these data via the adjacent nodes between sensor nodes and the server. The changing of physical phenomena will be monitored periodically in a server based on the receiving data from sensor nodes. Mobile Ad Hoc Network (MANET) is a flexible network topology that could be installed in disaster areas with a lack of infrastructure. This topology strongly supports the WSN system in sensor data transmitting. In this paper, we analyze the performance of 3 common MANET routing protocols, i.e. Ad Hoc On-demand Distance Vector (AODV), Dynamic Source Distance Vector (DSDV), and Optimized Link State Routing (OLSR). The three protocols have been examined by simulation using Network Simulator 3 (NS3) with 4 examination parameters, namely Packet Delivery Ratio (PDR), received data throughput, the percentage of packet loss, and transmitting delay. The result of the simulation shows that OLSR has better performance in the aforementioned parameter with the values 97,198%, 19,6399 Kbps, 2,802%, and 0,842 msec respectively based on the number of nodes provides.

Unmanned Aerial Vehicles Routing Formation Using Fisheye State Routing for Flying Ad-hoc Networks

Abstract: Flying Ad-hoc Networks creates rapid topology changes that causes routing problems between Unmanned Aerial Vehicle and ground base station. Mobile Ad-hoc networks and Vehicular Ad-hoc network protocols are conventionally adopted to overcome routing issues. But Still, they do not fully address the routing problem in Flying Ad-hoc Networks. In this paper, Fisheye state routing protocol is implemented and evaluated to fully overcome routing issues in a Flying Ad-hoc Network and fully utilize the limited resource of Unmanned Aerial Vehicles. Performance evaluation is measured in terms of throughput, average end-to-end delay, packet drop analysis as congestion measure with Ad-Hoc On-Demand Distance Vector (AODV), Distance Sequence Distance Vector (DSDV), Optimized Link State Routing (OLSR), Temporary Ordered Routing Protocol (TORA) and Dynamic Source Routing (DSR). Fisheye state routing protocol showed promising results regarding throughput, packet drop rate, and average end-to-end delay compared with traditional protocols. Moreover, with the suggested improvement of the parameters, network lifetime is increased, and resources harvesting becomes under control.

Trust Routing Protocol Based on Cloud-Based Fuzzy Petri Net and Trust Entropy for Mobile Ad hoc Network

Abstract: The trust-based routing mechanisms are proposed to enhance the security of the mobile ad hoc network (MANET), which use the performance metrics of a node to evaluate the trust value of the node. However, some performance metrics are fuzzy, which are easier to be described qualitatively than to be expressed quantitatively. Therefore, the inability to quantitatively express these performance metrics leads to the inaccuracy in the calculation of the trust values of nodes. Meanwhile, some routing mechanisms add the path with the highest credibility to routing table without considering the hop counts of the route in route selection, which reduces quality of service (QoS) of the routing. Aiming at the above problems, firstly, we use cloud model to deal with the fuzziness of performance metrics. Specifically, a trust reasoning model based on cloud model and fuzzy Petri net (FPN) is presented to evaluate the credibility of nodes. Then we propose a routing algorithm based on trust entropy. Routes with the minimum trust entropy are selected to add to routing table. This routing algorithm can reflect the comprehensive effect of route hops and the trust values of nodes on routing selection, thus improving QoS in MANET. Finally, the TUE-OLSR protocol is established based on the trust entropy routing algorithm and the optimized link state routing (OLSR) protocol. What’s more, the effectiveness of TUE-OLSR protocol is verified by simulation experiments, which illustrate that TUE-OLSR protocol performs better than existing trust-based OLSR protocols in terms of packet delivery ratio and average latency.

On Modeling Optimizations and Enhancing Routing Protocols for Wireless Multihop Networks

Abstract: The contribution of this paper is two fold. It first analyses the flooding strategies for the Wireless Multihop Networks (WMNs) then it enhances the reactive and proactive routing protocols. For analysis purpose, we select four widely used flooding techniques for routing: i. traditional flooding, ii. Time-To-Live based Expanding Ring Search (TTL-based ERS) flooding scheme, iii. TTL-based Scope Routing (SR) flooding and iv. Multi-Point Relays (MPR) flooding. These techniques play a vital role and act as a backbone for routing protocols. Therefore, we compare efficiency of these techniques for six widely used routing protocols: Ad-hoc On-demand Distance Vector (AODV), Destination Sequenced Distance Vector (DSDV), Dynamic Source Routing (DSR), DYnamic MANET On-demand (DYMO), Fish-eye Scope Routing (FSR) and Optimized Link State Routing (OLSR). DSDV uses traditional flooding, AODV, DSR and DYMO use TTL-based ERS flooding, FSR uses TTL-based SR flooding and OLSR uses MPR flooding. This paper also presents mathematical models for flooding techniques and studies the affects of these techniques on their respective protocols in terms of energy and time consumption. This is done to measure the cost incurred by the routing protocols in the form of routing overhead and latencies. A novel contribution of this work is the enhancement in search set values and intervals of routing algorithms to improve the efficiency of selected existing protocols. A detailed comparison analysis of selected protocols with their default and enhanced routing algorithms in NS-2 is also a part of this work.

Link Reliability-Based Adaptive Routing for Multilevel Vehicular Networks

Abstract: In multilevel vehicular ad-hoc network (VANET) scenario, dynamic vehicles, complex node distribution and poor wireless channel environment deteriorate the reliability of routing protocols. However, for the key issues of relay selection, existing algorithms analyze the wireless link performance without considering the influence of dynamics and shadow fading on location from GPS, as well as channel condition and buffer queue, which would lead to inaccurate link characterization and maladaptive to network variation. In this paper, we establish a dynamic link reliability model to portray the link complexity of multilevel VANET scenario, and propose a link reliability-based adaptive routing algorithm (LRAR) to improve the transmission efficiency. Firstly, we propose a Kalman filter-based estimation approach to amend GPS original data for precise location of vehicles. Then, we define link reliability to quantify the wireless link performance, and establish a multilevel dynamic link model (MDLM) to evaluate it. Moreover, to accurately describe the complexity of wireless links, we integrate the corrected GPS data and characteristics of multilevel VANET including vehicle dynamics, distribution hierarchy and shadow fading into the modeling of link reliability. Considering the difference of link state among diverse vehicles, a maximum deviation algorithm is introduced to adaptively calculate the weight of each parameter in the modeling. Finally, we formulate the routing decision as a multi-attribute decision problem, and select the link with highest reliability as transmission path. Simulation results demonstrate that LRAR outperforms the existing routing algorithms in terms of average end-to-end delay and packet delivery ratio.

Improving aerial image transmission quality using trajectory-aided OLSR in flying ad hoc networks

Abstract: UAVs have been widely used in various applications. Auto coordination of multiple UAVs through AI or mission planning software can provide significant improvements in many applications, including battlefield reconnaissance, topographical mapping, and search and rescue missions. Under such circumstances, the trajectory information is known for a set amount of time, and the system’s performance relies on the network between UAVs and their base. Here, a new protocol is proposed that takes the trajectory of UAVs as a known factor and uses it to improve optimized link state routing (OLSR). In this protocol, Q-learning is adopted to find the best route for the system. Additionally, a packet forwarding arrangement is described that addresses the common problem of deteriorating image quality often faced by UAVs. The simulation results show significant improvements over OLSR and GPSR under a sparsely distributed scenario, with the packet delivery ratio improved by over 30% and over 40 s reduction in the end-to-end delay.

A new position based routing algorithm for vehicular ad hoc networks

Abstract: The main requirement to make safer journey in VANET environment is minimum delay with high packet delivery rate. This ensures that all data packets are received with minimal delay to prevent any accident. This paper presents a new algorithm for VANET class routing protocol that covers sparse and coarse region of vehicles. It takes the advantage of road layout to improve the performance of routing in VANETs. The proposed algorithm uses real-time GPS tracking system to obtain traffic information for creating road based paths from source node to destination node. The optimize forwarding is used to figure out the forwarding node along the road pattern that form the path to deliver the data packets. The results shows that proposed algorithm obtain better results considering the various simulation parameters.

Towards Developing Enhanced Cluster-Based QoS-Aware Routing in MANET

Abstract: Creating dynamic communication infrastructures between mobile devices and satisfying the desires for time-sensitive multimedia applications have introduced new challenges in the design of protocols for mobile ad hoc networks. In this paper, to stream time-sensitive applications using mobile ad hoc network (MANET), we have selected the Optimal Link State Routing (OLSR) protocol. However, the protocol has high overhead because each node selects a set of multipoint relay (MPR) nodes. Therefore, we have proposed quality of service (QoS) supporting the MPR selection approach and a new lower maintenance clustering approach for minimizing the overhead of the network. As a result, the proposed approach showed a better result in the average end-to-end delay, packet delivery ratio, routing load, and throughput.

Total energy consumption analysis in wireless Mobile ad hoc network with varying mobile nodes

Abstract: The energy protocols that have a mechanisms of shortest path routing considered predominant in the networking scenarios. The interesting matter in the routing protocols designing deal with mobile ad hoc network (MANET) must have an energy efficient network for better network performances. The Performances of such routing protocols that can be assessed will be focused on many metrics like delay, throughput, and packet delivery. MANET is a distribution network, having no infrastructure and network decentralization. There routing protocols are utilized for detecting paths among mobile nodes to simplify network communication. The performance comparison of three protocols are Optimized Link State Routing (OLSR), the second is Ad hoc On-Demand Distance Vector (AODV), while the third is Dynamic Source Routing (DSR) routing protocols concerning to average energy consumption and mobile node numbers are described thoroughly by NS-3 simulator. The nodes number is changing between 10 and 25 nodes, with various mobility models. The performance analysis shows that the suggested protocols are superior in relations to the energy consumption for networking data transmission and the performance of the wireless network can be improved greatly.

Efficient Deployment with Throughput Maximization for UAVs Communication Networks.

Abstract: The article presents a throughput maximization approach for UAV assisted ground networks. Throughput maximization involves minimizing delay and packet loss through UAV trajectory optimization, reinforcing the congested nodes and transmission channels. The aggressive reinforcement policy is achieved by characterizing nodes, links, and overall topology through delay, loss, throughput, and distance. A position-aware graph neural network (GNN) is used for characterization, prediction, and dynamic UAV trajectory enhancement. To establish correctness, the proposed approach is validated against optimized link state routing (OLSR) driven UAV assisted ground networks. The proposed approach considerably outperforms the classical approach by demonstrating significant gains in throughput and packet delivery ratio with notable decrements in delay and packet loss. The performance analysis of the proposed approach against software-defined UAVs (U-S) and UAVs as base stations (U-B) verifies the consistency and gains in average throughput while minimizing delay and packet loss. The scalability test of the proposed approach is performed by varying data rates and the number of UAVs.

A Comparative Study on Routing Protocols: RIP, OSPF and EIGRP and Their Analysis Using GNS-3

Abstract: On the Internet, the routing of a data packet is the most important process. A routing protocol specifies the way to a router so that it can be connected to the internetworks with the help of a protocol called an Internet protocol. Internet applications make use of many routing protocols like RIPvl, RIPv2, OSPF, EIGRP, IGRP, etc. Each routing protocols have their own methods of routing a packet. This paper presents a basic comparative study of RIP, OSPF, and EIGRP protocols. The RIP makes use of a distance vector algorithm to choose the best path for a packet, OSPF makes use of a link state algorithm to decide the best path for a packet and EIGRP makes use of diffusing update algorithms to decide a path for a packet. In this paper, we are comparing and analyzing the performance of routing protocols such as RIP, OSPF, and EIGRP to decide the best protocol for routing packets.

A Routing Algorithm Based on Link State Information for LEO Satellite Networks

Abstract: Low earth orbit (LEO) satellite networks can provide global coverage, low-latency services to users. The satellite networks are multi-hop networks, and the dynamic characteristics of the networks bring great challenges to design efficient routing algorithms. In this paper, we proposed an improved routing algorithm based on inter-satellite link(ISL) state information and it is on-board autonomous control. The routing algorithm is divided into three phases, namely topology establishment phase, routing calculation phase and link failure response phase. Satellites make routing decisions for each hop based on the link state information with neighbor satellites and the network topology. The simulation results show that our routing algorithm has significant advantages in delivery ratio and end-to-end delay.

A Dual-Connectivity Mobility Link Service for Producer Mobility in the Named Data Networking.

Abstract: With the exponential growth of Cyber-Physical Systems (CPSs) technologies, the Internet of Things (IoT) infrastructure has evolved from built-in static infrastructure to a flexible structure applicable to various mobile environments. In this Internet of Mobile Things (IoMT) environment, each IoT device could operate simultaneously as a provider and consumer of information, and could provide new services through the exchange of such information. Named Data Networking (NDN), which could request data by content name rather than location (IP address), is suitable for such mobile IoT environments. However, in the current Named Data Networking (NDN) specification, producer mobility is one of the major problems in need of remedy. Previously proposed schemes for producer mobility use an anchor to hide the producer’s movement from consumers. As a result, they require a special anchor node and a signaling procedure to track the current locations of contents. A few anchorless schemes have also been proposed, but they still require mobility signaling and all NDN routers on the signaling path must understand the meaning of the signaling. We therefore propose an anchorless producer mobility scheme for the NDN. This scheme uses a dual-connectivity strategy that can be expressed as a soft handover. Whenever a producer changes its NDN Access Router (NAR), the new mobility link service located on the mobile producer’s old NDN face repairs the old link so that the connectivity with the pNAR can be maintained for a while. The old NDN face is removed after the new location information on the contents of the producer is disseminated over the NDN network by the Named-data Link State Routing Protocol (NLSR) routing protocol at the nNAR. The new mobility link service decouples connection and transaction to hide the collapse of the link. Therefore, the NDN’s mobility procedure could be simplified as the handover is defined as transaction completion as opposed to a breakdown of links. The proposed scheme prevents the routing information from being abruptly outdated due to producer mobility. Our simulation results show seamless handover when the producer changes its default access router.

Dual-Channel-Based Mobile Ad Hoc Network Routing Technique for Indoor Disaster Environment

Abstract: The existing network infrastructure may not work well in a disaster environment caused by a fire or an earthquake. Instead of relying on the existing infrastructure, communicating through a mobile ad hoc network (MANET) is recommended because MANET can configure a network without an infrastructured communication system. In addition, firefighters conducting emergency activities in harsh environments surrounded by flames and smoke need a communication system to assist their rapid firefighting operations. Existing work is not suitable for indoor firefighter communications because they did not consider the indoor disaster environment well. In this proposed scheme, dual channels (i.e., 2.4 GHz and sub-GHz bands) are used for an efficient routing table configuration. Data frame and HELLO message are exchanged through the 2.4 GHz band, while the neighbor list of each node is exchanged through the sub-GHz band. Each node can configure the routing table based on the exchanged neighbor list. A performance evaluation is conducted to compare the proposed technique with enhanced versions of optimized link state routing (OLSR) and destination-sequenced distance vector routing (DSDV). The results show that the proposed scheme outperforms the other two MANET routing algorithms (i.e., OLSR-mod and DSDV-mod) in terms of the packet delivery ratio (PDR), end-to-end delay, and initial routing table configuration time approximately 27.8%, 4.7%, and 166.7%, respectively.

cRetor: An SDN-Based Routing Scheme for Data Centers With Regular Topologies

Abstract: The blooming of cloud computing leads to the rapid expansion of data center networks (DCN) Conventional link state routing algorithms like OSPF are widely adopted in data center networks, however, those routing algorithms bring great control overheads and long convergence time Recently, topology-aware routing methods are considered to be efficient especially in data center networks with regular topologies Lots of topology-aware routing methods (eg, Fat-Tree and BCube) have been proposed for specific data center network topologies This paper first proposes a formalized method to describe regular topologies and a regular Topology Description Language (TPDL) based on this method TPDL is well designed to accurately define regular network topologies in a clear way leveraging their regularities Based on the Software-Defined Networking (SDN) technology, this paper also proposes a novel topology-aware routing scheme: cRetor (controller-side REgular TOpology Routing scheme) Different from other topology-aware routing methods, cRetor is a TPDL-based general routing method, which means it is expected to work on different kinds of regular topologies In this scheme, TDPL files are used as a priori knowledge to build an initial topology in the SDN controllers, which eliminates the process of topology discovery via Link Layer Discovery Protocol (LLDP) and hence relieves the bandwidth and processing burdens on controllers Besides, we also apply the A-star algorithm to SDN controllers to speed up the routing selection, where TPDL's distance formulas act as the heuristic function The experimental results show that cRetor outperforms LLDP-based SDN, OSPF and DCell in routing calculation performance, convergence speed, routing overheads and fault tolerance

A Novel Framework for Resource Discovery and Self-Configuration in Software Defined Wireless Mesh Networks

Abstract: A novel framework is proposed for software defined wireless mesh networks involving mobile switches and controllers operating under in-band control in order to self-configure depending on the network dynamics. Besides the addition/removal of nodes (including switches and controllers) to/from the network in real-time, the problem becomes more challenging for switches to select an appropriate controller from multiple physical controllers. Therefore, first we design a resource discovery scheme to address the dynamic addition and removal of nodes with a software defined optimized link state routing (SD-OLSR) protocol. Apart from resource discovery, SD-OLSR captures the network dynamism and provides a global network view to the controller. Further, two controller handoff schemes, controller-initiated handoff (CIH) and switch-initiated handoff (SIH), are designed for switches to efficiently handover to a suitable controller. The framework and handoff schemes are tested using a software defined wireless mesh network testbed involving mobile switches and controllers operating under in-band control. The results show that SIH performs better in terms of SDN control overhead and PacketIn-FlowMod delay, while CIH outperforms SIH in terms of the number of handoffs and controller handoff time. A fair trade-off between the number of handoffs and the desired performance metric can be achieved by tuning the handoff threshold in both CIH and SIH schemes. As an added benefit, our framework provides better load sharing among the controllers in terms of flow-rule requests.

A hybrid link protection scheme for ensuring network service availability in link-state routing networks

Abstract: The internet is playing an increasingly crucial role in both personal and business activities. In addition, with the emergence of real-time, delay sensitive and mission-critical applications, stringent network availability requirement is put forward for internet service providers (ISPs). However, commonly deployed intradomain link-state routing protocols react to link failures by globally exchanging link state advertisements and recalculating routing table, inevitably causing significant forwarding discontinuity after a failure. Therefore, the loop-free criterion (LFC) approach has been widely deployed by many ISPs for coping with the single network component failure scenario in large internet backbones. The success of LFC lies in its inherent simplicity, but this comes at the expense of letting certain failure scenarios go unprotected. To achieve full failure coverage with LFC without incurring significant extra overhead, we propose a novel link protection scheme, hybrid link protection (HLP), to achieve failure resilient routing. Compared to previous schemes, HLP ensures high network availability in a more efficient way. HLP is implemented in two stages. Stage one provides an efficient LFC based method (MNP-e). The complexity of the algorithm is less than that of Dijkstra's algorithm and can provide the similar network availability with LFC. Stage two provides backup path protection (BPP) based on MNP-e, where only a minimum number of links need to be protected, using special paths and packet headers, to meet the network availability requirement. We evaluate these algorithms in a wide spread of relevant topologies, both real and synthetic, and the results reveal that HLP can achieve high network availability without introducing conspicuous overhead. HLP not only needs around 10% time of that of full protection, but also provides full protection capabilities that full protection provide.

Integrating Mobile Ad Hoc Networks with the Internet Based on OLSR

Abstract: Although a standalone and isolated mobile ad hoc network (MANET) is practical in many scenarios, integration with the Internet is much more advantageous. The integration of a MANET with the Internet provides MANET users with Internet access and hence increases the scope of the MANET application. In addition, the Internet can benefit from this integration by an extension of the network coverage area. However, the integration of heterogeneous networks raises many issues. To overcome the incompatibilities between different architectures, gateways are used. This paper proposes a lightweight integration scheme for a MANET and the wider Internet, based on the optimized link state routing (OLSR). OLSR routing messages are reengineered and optimized to meet the needs of integration without involving additional routing messages for gateway discovery. The compulsory registration of a MANET node with a gateway node in a traditional integration is not required in the proposed approach, meaning that nodes can move freely within the local MANET with no disruption in the connection to another node in the external network. The proposed system is evaluated using the OMNET++ network simulator and is compared to another existing system. The simulation results demonstrate the validity of the proposed approach.

The Routing Protocol Efficiency of Named Data Network

Abstract: An efficient routing protocol is needed in transmitting data on the network, especially on Named Data Network. This means that the routing mechanism must be made in such a way that the data transmission rate is close to the transmission link rate. This study investigates the effect of a geographic-based routing protocol compared to the link state from an efficiency point of view. The system model is built to see the effect of link bitrate, path stretch, packet header, and packet size on the efficiency of the routing protocol in sending data. From the mathematical model, Link State routing is outperformed geographic routing protocol for 24% on average.

3DEOR: an opportunity routing protocol using evidence theory appropriate for 3D urban environments in VANETs

Abstract: The vehicular ad hoc network (VANET) is a promising technology to improve the comfort and safety of passengers, roads and urban traffic. Applications applied to VANETs require efficient routing protocols. Urban environments include tunnels, subways, overpasses, and multilevel highways, which indicate the multilevel information environment and specific conditions of radio channel dissemination. In this paper proposed a three-dimensional (3D) evidence theory based, opportunistic routing protocol, called 3DEOR, which address the above issues using a new hybrid criterion called PAL. The PAL criterion includes three metrics of packet delivery probability to compensate for unreliable dissemination environments, packet advancement appropriated to 3D environments to reduce the number of hop counts and level to improve link connectivity. Prioritise the relay set members based on the new criteria to select the best relay node. In cases where there is no certainty, the evidence theory can be a good choice for combining the three metrics of the PAL criterion. The simulation results show the superiority of the proposed protocol over the 3D link state aware geographic opportunistic (3DLSGO) and 3D greedy perimeter stateless routing (3DGPSR) protocols in network performance indices such as packet delivery rate, end-to-end delay and average hop count.

Improved proactive routing protocol considering node density using game theory in dense networks

Abstract: In mobile ad hoc networks, network nodes cooperate by packet forwarding from the source to the destination. As the networks become denser, more control packets are forwarded, thus consuming more bandwidth and may cause packet loss. Recently, game theory has been applied to address several problems in mobile ad hoc networks like energy efficiency. In this paper, we apply game theory to reduce the control packets in dense networks. We choose a proactive routing protocol, Optimized Link State Routing (OLSR) protocol. We consider two strategies in this method: willingness_always and willingness_never to reduce the multipoint relay (MPR) ratio in dense networks. Thus, nodes with less influence on other nodes are excluded from nomination as MPRs. Simulations were used to confirm the efficiency of using our improved method. The results show that the MPR ratio was significantly reduced, and packet delivery ratio was increased compared to the conventional protocol.