이동 애드혹 네트워크에서의 부하 균등화 및 공평성 지원 방법

Abstract—On demand routing protocols for ad hoc networks such as Ad Hoc On Demand Distance Vector (AODV) initiate a route discovery process when a route is needed by flooding the network with a route request packet. The route discovery process in such protocols depends on a simple flooding as a broadcast technique due to its simplicity. Simple flooding results in packet congestion, route request overhead and excessive collisions, namely broadcast storm problem. A number of routing techniques have been proposed to control the simple flooding technique. Ideally, the broadcast of route request or the route discovery process must be stopped as soon as the destination node is found. This will free the network from many redundant packets that may cause network collision and contention. In this paper, chasing packet technique is used with standard AODV routing protocol to end the fulfilled route requests. The chase packet is initiated by the source node and is broadcasted in parallel with route request packet. As soon as the destination is found the chase packet starts its work by trying to catch and discard the route request in early stages before it broadcasts further in the network. Performance evaluation is conducted using simulation to investigate the performance of the proposed scheme against the existing approach that uses chase packet technique such as Traffic Locality Route Discovery Algorithm with Chase (TLRDA-C). Results reveal that the proposed scheme minimizes end-to-end packet delays and achieves low routing request overhead.

The two ad-hoc routing protocols, Ad-hoc On demand Distance Vector (AODV) and Dynamic Source Routing (DSR) suffer a number of shortcomings. The main issues are longer path set up time in case of link failures, scalability problem because of routing overhead and etc. A combination of the two routing protocols called DOA (DSR over AODV) is used to overcome these issues. DOA is usually implemented using a model called Way Point Routing model in which the problem of position estimation errors occurs. This work enhances DOA with a new algorithm called Exponential Weighted Moving Average (EWMA) for on-line updating of nodal contact probability to minimize the possibilities of position estimation errors. In this work, new packet called Delay to Send (DTS) packets instead of NACK packets has been used in addition to RTS and CTS packets. Here DTS packets are to recover the delayed data within a certain time period instead of dropping the packet after final retransmission in case of delay due to unexpected traffic in packet delivery. A Simulation analysis is carried out to analyze the performance of DOA with EWMA compared to AODV and DSR. It proves that DOA with EWMA reduces the routing overhead by 80% and scalability problem that occurred in AODV and DSR.

Ad Hoc Routing with Distributed Ordered Sequences

Mobile Ad Hoc Networks (MANETs) pose challenges in terms of power control, due to their fixed transmission power, the mobility of nodes and a constantly changing topology. High levels of power are needed in wireless networks, particularly for routing. In order to address this problem, power aware routing protocols have been proposed, with the aim of maximising the lifetime of the network. This paper presents an enhancement to the Ad Hoc On Demand Distance Vector (AODV) protocol, by reducing transmission power, when a large number of other radios are within range. This protocol, called DP-AODV (Dynamic Power AODV) combines the hello packet mechanism and the power control mechanism in order to reduce interference between nodes and increase the throughput in the network, thus reducing the overall power consumption. A performance evaluation of this enhanced protocol is carried out in comparison with three standard routing protocols, Ad Hoc On Demand Distance Vector (AODV), Ad Hoc On Demand Multipath Distance Vector (AOMDV) and Dynamic Source Routing (DSR), using network simulator 2 (NS2). Keywords-MANET; Dynamic Power; Density; Mobility; Interference.

Mobile Ad hoc Network (MANET) is the cornerstone for the Internet of Things (IoT) and Vehicle to Everything (V2X) networks, its devices are remarkable of lightweight to be portable and free to join or disjoined the network. Therefore, one of the MANET routing types is reactive routing protocols. Reactive routing protocols set up the connection between devices either on-demand such as Ad Hoc On-demand Distance Vector (AODV) protocol or source routing such as Dynamic Source Routing (DSR) protocol. Reactive routing protocols increase routing overhead on discovering new routes. Thus routing overhead, and delay will increase. In this paper, the method of generating a fuzzy model is presented. Also, a tuned fuzzy stability model is introduced to handle the imprecision of routing decisions by the Fuzzy Stability model for Ad Hoc On-demand Distance Vector (FSAODV) and Fuzzy Stability model for Dynamic Source Routing (FSDSR). The results showed that FSAODV and FSDSR have outperformed the state of art protocols AODV and DSR respectively.

Mobile Ad-hoc Networks (MANETs) features such as open medium, dynamic topology, lack of centralised management and lack of infrastructure expose them to a number of security attacks. Black hole attack is one type of attack that is more common in MANET reactive routing protocols such as Ad-hoc On-demand Distance Vector (AODV) and Dynamic Source Routing (DSR). Black hole attack takes advantage of route discovery process in reactive routing protocols. In this type of attack, a malicious node misleads other nodes in the network by pretending to have the shortest and updated route to a target node whose packets it wants to interrupt. It then redirects all packets destined to a target node to itself and discards them instead of forwarding. This paper analyses the performance of AODV and DSR when attacked by black hole, by varying the mobility of the nodes in the network. The analysis is carried out by simulating scenarios of AODV based MANET and DSR based MANET using Network Simulator 2 (NS-2) and introducing the black hole attack in each of the scenarios. The different scenarios are generated by changing the mobility of the nodes. The performance metrics that are used to do the analysis are throughput, packet delivery ratio and end-to-end delay. The simulation results show that the performance of both AODV and DSR degrades in the presence of black hole attack. Throughput and packet delivery ratio decrease when the network is attacked by black hole because the malicious node absorbs or discards some of the packets. End-to-end delay is also reduced in the presence of a black hole attack because a malicious node pretends to have a valid route to destination without checking the routing table, and therefore shortens the route discovery process. The results also show that throughput decreases slightly when mobility of the nodes is increased in the network. The increase in the speed of the nodes decreases both end-to-end delay and packet delivery ratio.

This paper conduct a comprehensive simulation study on the behavior of TCP-friendly Rate Control (TFRC) protocol over Ad-Hoc On Demand Vector (AODV) routing protocol and Dynamic Source Routing (DSR) protocol. The aim are first, to measure the performance of TFRC in terms of throughput, delay and jitter. The second objective is to identify which Mobile Ad-Hoc Network (MANET) routing protocols work well with TFRC. We conduct the experiment by sending multimedia streaming traffic carried by TFRC over AODV and DSR respectively. Random-Waypoint mobility model is used for both experiments. Results obtained shows that in average TFRC over AODV has more throughput and less delay as compared with TFRC over DSR. However, in terms of jitter, TFRC over DSR gives better result.

Recently mobile ad-hoc networks (MANET) have found widespread applications. In this infrastructure-less networks the routes have to be refreshed often due to mobility of nodes which also acting as routers. Many ad-hoc routing protocols have been proposed, of which on-demand routing protocols are very popular. To meet the scarce of network resources, the need of the time is to develop a protocol which makes efficient use of resources. In this paper we propose a mobility adaptive cross layer design to enhance the performance of ad-hoc on-demand distance vector (AODV) routing protocol by establishing stable routes. The adaptive decision making according to the speed of mobile nodes on route request (RREQ) packet forwarding results in stable routes. Comparing with the basic AODV protocol, the new cross layer algorithm has better performance as shown with the simulation results obtained using the network simulator, GloMoSim.

Vehicular Ad Hoc Networks (VANET) are key to realizing Intelligent Transportation Systems (ITS). Although VANETs belong to the class of Mobile Ad Hoc Networks (MANET), and there are numerous routing protocols for MANETs, none of these protocols are applicable for VANETs. In particular, VANETs are highly dynamic due to high speed mobility of vehicles and traditional routing algorithms for MANETs cannot deal with such dynamicity of network nodes. Several comparative studies have suggested AODV (Ad hoc On-Demand Distance Vector), a well known MANET protocol that is adaptive to dynamic changes in network and makes efficient utilization of network resources, to be the best candidate for dealing with VANETs. However, verbatim adoption of AODV is not an efficient routing solution for VANETs. Recent works therefore proposed various modifications and/or additions to AODV to make it suitable for VANETs. It is particularly important to control congestion in VANETs by efficiently dealing with the AODV "Route Request" (RREQ) packets. In this paper, we propose Pro-AODV (Proactive AODV), a protocol that uses information from the AODV routing table to minimize congestion in VANETs, yet sustains other performance metrics at acceptable levels. The novelty and elegance in Pro-AODV comes from the fact that it does not require the execution of any additional logic, it is sufficient to know only the size of the routing table at each node.

Mobile Ad-hoc Networks (MANETs) operate without infrastructure where nodes can move randomly. Therefore, routing in MANETs is a challenging task. In this paper we evaluate the performance of three important MANET routing protocols: Ad hoc On-Demand Distance Vector (AODV), Dynamic Source Routing (DSR) and Optimized Link State Routing (OLSR) when employed to forward scalable video contents. AODV and DSR are reactive protocols in that routing paths are established once needed. On the other hand, OLSR is a proactive routing protocol where routing information is exchanged and maintained continuously. The goal of the performance evaluation in this study is to assess the performance of AODV, DSR and OLSR in communicating scalable video contents. In the simulation part of this paper, a real video sequence is communicated where the characteristics and quality of the video decoded at receiver nodes are evaluated. NS2 along with extensions and other evaluation frameworks have been used to assess the performance of the MANET routing protocols when used for scalable video communication. The framework allows starting from a raw video that is encoded, packetized, transmitted through a network topology and collected at receiver to be decoded, played, and evaluated. Delay and timing constraints are taken into consideration when decoding the received video packets.

Wireless sensor network (WSN) with several sensors is used to group measurements of certain physical quantities or environmental conditions, including sound, temperature, pressure, vibration, motion, or pollution, at various locations and ranges. In WSNs, several protocols address the issue of routing. Sensor nodes in WSN usually have limited energy resources and storage capacities. Therefore, the issue of energy usage in sensors and protocols is very important. This paper analyzes and compares the quality of service (QoS) performances of three important routing protocols of the mobile ad-hoc network (MANET) including Ad-hoc on-demand distance vector (AODV), dynamic source routing (DSR), and destination sequenced distance vector (DSDV), in a smart building case study. The QoS evaluation metrics include residual energy of nodes, instant throughput (IT), average throughput (AT), packet delivery ratio (PDR), packet loss ratio (PLR), and route discovery latency (RDL) based on IEEE 802.15.4 MAC protocol standard. The simulation is carried out using NS2, and the WSN has 16 fixed and 4 mobility nodes with different speeds and paths. The simulation results illustrate that average throughput in AODV is 1.985118 (kbps), however, the figures for DSR and DSDV are 1.977780 and 1.720700 (kbps), respectively. PDR, also, in DSR stands at 1.0, but the figures for AODV and DSDV are lower with the range of 0.999572 and 0.997930, respectively. Overall, The DSR protocol provides a better performance compared to AODV and DSDV routing protocols in terms of PLR and PDR. Also, AODV has better efficiency in RDL and AT compared to other assumed protocols.

In this work, we compare a recently proposed routing protocol, the multi-parent hierarchical (MPH) protocol, with two well-known protocols, the ad hoc on-demand distance vector (AODV) and dynamic source routing (DSR). For this purpose, we have developed a simulator, which faithfully reifies the workings of a given protocol, considering a fixed, reconfigurable ad hoc network given by the number and location of participants, and general network conditions. We consider a scenario that can be found in a large number of wireless sensor network applications, a single sink node that collects all of the information generated by the sensors. The metrics used to compare the protocols were the number of packet retransmissions, carrier sense multiple access (CSMA) inner loop retries, the number of nodes answering the queries from the coordinator (sink) node and the energy consumption. We tested the network under ordinary (without attacks) conditions (and combinations thereof) and when it is subject to different types of jamming attacks (in particular, random and reactive jamming attacks), considering several positions for the jammer. Our results report that MPH has a greater ability to tolerate such attacks than DSR and AODV, since it minimizes and encapsulates the network segment under attack. The self-configuring capabilities of MPH derived from a combination of a proactive routes update, on a periodic-time basis, and a reactive behavior provide higher resilience while offering a better performance (overhead and energy consumption) than AODV and DSR, as shown in our simulation results.

The use of dominating-set neighbor elimination as an integral part of the distribution of route requests using the ad hoc on-demand distance vector (AODV) protocol as an example of on-demand routing protocols is investigated. We use detailed simulations to show that simply applying dominant pruning (DP) to the distribution of route requests in AODV results in pruning too many route requests in the presence of mobility and cross-traffic. Accordingly, we introduce several heuristics to compensate the effects of DP and show that the resulting AODV with dominating set heuristics (AODV-DS) has comparable or better delivery ratio, network load, and packet latency than the conventional AODV. AODV-DS exhibits over 70% savings on RREQ traffic than conventional AODV, and in some situations, AODV-DS may have a lower control overhead using Hello packets than conventional AODV without Helios.

Hybrid Wireless Mesh Networks (HWMNs) based on the IEEE 802.11 are being increasingly deployed as a varied network of Mobile Ad-hoc Network (MANET) to provide users with extended coverage for wireless Internet access. HWAN, however, has a problem of too wide broadcasting of the Route Request (RREQ) in the route discovery of the Ad hoc Ondemand Distance Vector (AODV) protocol. In this paper, to enhance the performance of the AODV protocol, we have transformed it into a multipath protocol and proposed a new protocol that overcomes disadvantage of AODV by composing the neighbor table for overloaded RREQ. The neighbor table is provided in the form of metric using several items including the bandwidth. This can bring the localization effect of the nodes and we can expect a performance improvement by preventing an overloaded RREQ. Through the simulation, we could confirm better performance in packet loss rate, throughput, packet delivery ratio and routing overhead than the DSR protocol and AODV protocol.

In this paper, we efficiently adapt the prominent Ad hoc On-demand Distance Vector (AODV) routing protocol with a reactive Local Link Repair (AODV-LR) for effective deployment in Mobile Ad hoc Sensor Networks (MASNETs) with restricted power and bandwidth. We introduce two replacement mechanisms to the local repair phase of the AODV. Our new approaches are self-repairing AODV algorithms called Reactive Self-repairing AODV (AODV-RSR) and Pre-emptive Self-repairing AODV (AODV-PSR). These two algorithms are able to find an alternative route to a failing link without depending only on broadcasting Route Request (RREQ) packets. Experimental results show that the new algorithms achieve better performance than the AODV-LR and Self-repair Algorithm (SRAODV) by obtaining lower packet delay, higher packet delivery ratio and lower control message overhead.