Top PDF A Comparison of the TCP Variants Performance over different Routing Protocols on Mobile Ad Hoc Networks

The experiments were conducting using the ns-2 network simulator[13], developed at the University of California at Berkeley, with the wireless extensions provided by the CMU Monarch Project. The radio model is based on the Lucent Technologies WaveLAN 802.11 product, providing a 2 Mbps transmission rate and transmission range of 250 m. The link layer modeled is the Distributed Coordination Function (DCF) of the IEEE 802.11 wireless LAN standard. In this simulation 25 mobile nodes moved in an area of 500m x 500m for a period of 500 seconds. Random Waypoint (RW) mobility pattern was generated using the setdest tool which is a part of the ns-2 distribution. The maximum speed Vmax was set to 0, 1, 2, 5 and 10 m/sec to generate different movement patterns for same mobility model. The traffic pattern was generated by the cbrgen tool that is part of the ns-2 distribution. The traffic consisted of 1, 2, 5, 10 and 15 FTP connections. The source destination pairs were chosen at random. The data rate used was 8 packets/sec, window size 32 and the packet size was 512 bytes. The three thresholds α, and are set to be 1, 3 and 1, and parameter p in slow start phase is set to be 1/8 as default.

Due to high mobility of nodes in the network it is quite often difficult to set the right priority for the forwarding nodes. Generating candidate lists based on metrics like hop count, expected transmission count may not lead to optimal paths for the data packet. Using blind opportunistic forwarding for better performance may lead to enormous routing overhead. In order to improve the performance a new class of opportunistic routing protocols were found out which used various statistical measures and learning tools to identify the list of potential forwarders and to prioritize them. A number of Probabilistic Opportunistic Routing protocols [43-51] were proposed to improve the quality of service in highly mobile ad hoc networks. Encounter Based Routing, (EBR) [48] is of the popular and widely used protocol in this category. EBR protocol was proposed to decrease the number of duplicate transmissions in the network. EBR establishes an upper limit for the duplicate packets generated for transmission of a data packet in the network to limit the number of duplicate packets.EBR measures the number of encounters each node is having with the other nodes in the network. This encounter value forms the basis of assignment of priority for the forwarding nodes in the network. Nodes with more number of encounters are assumed to have better probability of data delivery at the destination node and are selected as the best forwarder over the other nodes. The major advantage of EBR is that it reduced the number of duplicate transmissions in the network and increased bandwidth and reduced the delay in transmissions. The major drawback of this protocol was that it could not increase the delivery rate in the network.

Fig.2: Mobile Ad-hoc Network II. ROUTING PROTOCOL A routing protocol specifies how routers communicate with each others. The routing protocols for ad hoc networks have been classified into three categories: Table-driven protocols, On-demand protocols and Hybrid routing protocols [4]. They are differing from each other on the way they obtain the routing information. The table driven protocols usually maintain the routing table of the whole network and all nodes continuously updates the routing table from dynamically changing topology of the network. Whereas the on-demand protocols only try to keep routes whenever it is required [5]. Whenever a node wants to send a data packet from source to destination, it requests for route discovery process. The route remains valid till the destination is reachable or until the route is no longer needed. A third category is also there which combines both table driven and on-demand protocol. In the routing, all the routing protocols have to follow must two basic functions first is selection of shortest path known as route between sources to destination and second is provide the delivery to right destination. From the exits routing protocol we have chosen to analyze the performance of AODV and DSDV routing protocols in MANET and WSN.

promise to offer high data rate over large areas to a large number of users where broadband is unavailable. This is the first industry wide standard that can be used for fixed wireless access with substantially higher bandwidth than most cellular networks [1], [2]. Development of this standard facilitates low cost equipment, ensure interoperability, and reduce investment risk for operators. In the recent years, IEEE 802.16 working group has developed a number of standards for WiMAX. The first standard IEEE 802.16 was published in 2001 and focused on the frequency range between 10 and 66 GHz and required line-of-sight (LOS) propagation between the sender and the receiver [3]. This reduces multipath distortion, thereby increases communication efficiency. Theoretically IEEE 802.16 can provide single channel data rates up to 75 Mbps on both the uplink and downlink. Providers could use multiple IEEE 802.16 channels for a single transmission to provide bandwidths of up to 350 Mbps [4]. However, because of LOS transmission, cost-effective deployment is not possible. Consequently, several versions came with new features and techniques. IEEE 802.16-2004, has been developed to expand the scope to licensed and license-exempt bands from 2 to 11 GHz. IEEE 802.16-2004 specifies the air interface, including the Media Access Control (MAC) of wireless access for fixed operation in metropolitan area networks. Support for portable/mobile devices is considered in IEEE 802.16e standard, which is published in December 2005. WiMAX networks consist of a central radio Base Station (BS) and a number of Subscriber Stations (SSs). In Mobile WiMAX network, BS (which is fixed) is connected to public network and can handle multiple sectors simultaneously and SSs are mobile.

Abstract — a mobile ad hoc network is a collection of autonomous mobile nodes that communicate with each other over wireless links. Such networks are expected to play increasingly important role in future civilian and military settings, being useful for providing communication support where no fixed infrastructure exists or the deployment of a fixed infrastructure is not economically profitable and movement of communicating parties is possible. However, since there is no stationary infrastructure such as base stations, mobile hosts need to operate as routers in order to maintain the information about the network connectivity. Therefore, a number of routing protocols have been proposed for ad hoc wireless networks. In this paper, we study and compare the performance of the following routing protocols AODV, DSR, and DSDV. For experimental purposes, we have considered three terrain area 900m x 700m, 1100 x 600m and 1400m x 900m and illustrate the performance of the routing protocol across two different parameters Average Throughput and Number of Dropped Packets. Our simulation result shows that both AODV and DSR are performing better as compared to DSDV. Performance of DSR is better among AODV, DSR and DSDV in case of average throughput and number of dropped packets for increasing speed with varying terrain range.

25 can react to network changes. Some protocols choose a single path from all available routes, that path information alone is stored in the routing table. In multipath, all available paths are stored in the routing table it causes higher throughput. It also supports multiplexing over multiple lines. A flat routing protocol [7] considers all routers as peers. In such routing all router would receive the same routing updates from all other routers. But in hierarchical routing protocol [8] there is some classification among routers. They may not receive same information; they only receive routing updates from other routers within their network also it keeps local traffic information. It reduces the bandwidth overhead required by the routing protocol and improves network performance. In distance vector routing [1], routing decisions are based on the distance of the remote destination in terms of the number of network layer hops that the packet will have to traverse. In link state routing [1], routing decisions based on messages received from other routers in the network that give information about the state of the links connected to them.

In Mobile Ad-Hoc Networks (MANETs), mobile devices are equipped with power (energy). In order to utilize this energy equipped devices efficiently for transmission of data packets, many energy aware routing strategies are followed. As a key note to these routing strategies, the energy aware performance metrics are analyzed on two routing protocols like Ad-Hoc On Demand Distance Vector Protocol (AODV) and Destination Sequenced Distance Vector Routing Protocol (DSDV). The comparison results prove that AODV protocol can be adopted for any routing strategy, in order to increase the performance of the network lifetime in comparison with DSDV.

Future mobile Ad hoc networks (MANETs) are expected to be based on all-IP architecture and be capable of carrying multitudinous real-time multimedia applications such as voice, video and data. It is very necessary for MANETs to have a reliable and efficient routing and quality of service (QoS) mechanism to support diverse applications which have variances and stringent requirements for delay, jitter, bandwidth, packet loss. Routing protocols such as AODV, AOMDV, DSR and OLSR use shortest path with the minimum hop count as the main metric for path selection, hence are not suitable for delay sensitive real time applications. To support such applications delay constrained routing protocols are employed. These Protocols makes path selection between source and destination based on the delay over the discovered links during routing discovery and routing table calculations. We propose a variation of a node-disjoint Multipath QoS Routing protocol called Cross Layer Delay aware Node Disjoint Multipath AODV (CLDM- AODV) based on delay constraint. It employs cross-layer communications between MAC and routing layers to achieve link and channel-awareness. It regularly updates the path status in terms of lowest delay incurred at each intermediate node. The performance of the proposed protocol is compared with single path AODV and NDMR protocols. Proposed CLDM-AODV is superior in terms of better packet delivery and reduced overhead between intermediate nodes.

Abstract —The mobile ad hoc network (MANET) is nothing but the wireless connection of mobile nodes which provides the communication and mobility among wireless nodes without the need of any physical infrastructure or centralized devices such as access point or base station. The communication in MANET is done by routing protocols. There are different categories of routing protocols introduced with different goals and objectives for MANETs such as proactive routing protocols (e.g. DSDV), reactive routing protocols (e.g. ADOV), geographic routing protocols (e.g. GRP), hybrid routing protocols etc. There are two important research problems with such routing protocols to address such as efficient load balancing and energy efficiency. In this paper, we are focusing on evaluation and analysis of efficient load balancing protocol design for MANET. Inefficient load balancing technique results in increasing routing overhead, poor packet delivery ratio, and other Quality of Service (QoS) parameters. In literature, there are a number of different methods proposed for improving the performance of routing protocols by efficient load balancing among mobile nodes communication. However, most of the methods suffer from various limitations. In this paper, we propose a novel technique for improved the QoS performance of load balancing approach as well as increasing the network lifetime. Evaluation of Network lifetime is out of scope of this paper.

with packet delivery fraction and end-to-end delay, where AODV has the best all round performance. DSR is suitable for networks with moderate mobility rate. It has low overhead that makes it suitable for low bandwidth and low power network. Mobility kinds have been specified and implemented in [2] where the mobility of node affects total performance of the routing protocols. The research in [3] evaluate the performance of DSR routing protocol under CBR and TCP variants. Research in [4] integrated a discussion on protocols of dynamic source routing (DSR), ad-hoc on-demand distance vector (AODV), TORA and OLSR, regarding scalability and mobility, where OLSR was the most favorite proactive routing protocol, while AODV has been designated as the most effective on-demand protocol for MANET scenarios. The author in[5] also evaluate the performance of different TCP variants such as Tahoe, Reno, New reno and SACK under different node speeds and its effect on Throughput, End to end delay, FTP download response time and FTP upload response time. Also MANET TCP optimization has been investigated in many studies [6, 7]. Due to intolerance mechanisms of TCP in dealing with link failures, this leads to incapability of distinguishing the difference between network congestions and link failures in MANET. Many research addressed the TCP performance problems due to route failures in MANETs [8]. A study conducted in [9] regarding the Westwood, TCP Reno, and BIC-TCP demonstrated the superiority of Reno variant over the others. However it lacked in recognizing different realistic scenarios with one source of TCP traffic was simulated in this research. The research in [10] discussed the performance evaluations of Reno, Tahoe, New Reno and SACK in different MANET realistic scenarios under the conditions of fading, signal attenuation, and multipath. It was shown here that TCP Reno version overcame the other congestion control algorithms regarding throughput, congestion window, and goodput.

MANET (Mobile Ad-hoc network) forms a temporary network of wireless mobile nodes without any infrastructure where all nodes are allowed to move freely, configure themselves and interconnect with its neighbors to perform peer to peer communication and transmission. TCP (Transmission Control Protocol) offers reliable, oriented connection and mechanism of end to end delivery. This article provides the review and comparison of existing variants of TCP for instance: The TCP Tahoe, The TCP Reno, The TCP New Reno, The Lite, The Sack, The TCP Vegas, Westwood and The TCP Fack. TCP’s performance depends on the type of its variants due to missing of congestion control or improper activation procedures such as Slow Start, Fast Retransmission, and Congestion Avoidance, Retransmission, Fast Recovery, Selective Acknowledgement mechanism and Congestion Control. This analysis is essential to be aware about a better TCP implementation for a specific scenario and then nominated a suitable one.

Mobile Ad hoc Network (MANET) is a collection of mobile nodes in which the wireless links are frequently broken down due to mobility and dynamic infrastructure. Routing is a significant issue and challenge in ad hoc networks. Many routing protocols have been proposed like OLSR, AODV so far to improve the routing performance and reliability. In this paper, we describe the Optimized Link State Routing Protocol (OLSR) and the Ad hoc On-Demand Distance Vector (AODV). We evaluate their performance through exhaustive simulations using the Network Simulator 2 (ns2) by varying conditions (node mobility, network density). Keywords - MANET; OLSR; AODV; ns2.

An adhoc network is a collection of nodes that do not need to rely on a predefined infrastructure to stablish and maintain pending on there capacity with respect to cpu, memory and battery. With the proliferation of mobile computing devices, the demand for continuous network connectivity regardless of physical location has spurred interest in the use of mobile ad hoc networks. A mobile ad hoc network is a network in which a group of mobile computing devices communicate among themselves using wireless radios, without the aid of a fixed networking infrastructure. Their use is being proposed as an extension to the Internet, but they can be used anywhere that a fixed infrastructure does not exist, or is not desirable. the congestion control mechanism of TCP reacts adversely to packet losses due to temporarily broken routes in wireless networks. So, i propose a simple heuristic, called fixed RTO, to distinguish betien route loss and network congestion and thereby improve the performance of the routing algorithms. The TCP protocol has been extensively tuned to give good performance at the transport layer in the traditional wired network environment. Hoiver, TCP in its present form is not ill-suited for mobile ad hoc networks (MANETs) where packet loss due to broken routes can result in the counterproductive invocation of TCP’s congestion control mechanisms.

fluctuations in route updates, DSDV employs a "settling time" data, which is used to predict the time when route becomes stable. In DSDV, broken link may be detected by the layer-2 protocol [2], or it may instead be inferred if no broadcasts have been received for a while from a former neighboring node. In this paper the performance comparison between three routing protocols, namely AODV (Ad hoc On Demand Distance Vector), DSDV (Destination Sequenced Distance Vector) and the Improvement of DSDV (I-DSDV). While all routing protocols use sequence numbers to prevent routing loops and to ensure the freshness of routing information, AODV and DSDV differ drastically in the fact that they belong to two different routing families [3]. Namely, AODV is a reactive protocol (routes are only generated on demand, in order to reduce routing loads), and DSDV is a proactive protocol (with frequent updates of routing tables regardless of need).

Mobile Ad-Hoc Network (MANET) is a collection of wireless mobile hosts forming a temporary network without the aid of any stand-alone infrastructure or centralized administration. Mobile Ad-hoc networks are self-organizing and self-configuring multihop wireless networks where, the structure of the network changes dynamically. This is mainly due to the mobility of nodes. The Nodes in the network not only acts as hosts but also as routers that route data to or from other nodes in network. In mobile ad-hoc networks a routing procedure is always needed to find a path so as to forward the packets appropriately between the source and the destination. The main aim of any ad-hoc network routing protocol is to meet the challenges of the dynamically changing topology and establish a correct and an efficient communication path between any two nodes with minimum routing overhead and bandwidth consumption. The design problem of such a routing protocol is not simple since an ad hoc environment introduces new challenges that are not present in fixed networks. A number of routing protocols have been proposed for this purpose like Ad Hoc On Demand Distance Vector (AODV), Dynamic Source Routing (DSR), Destination- Sequenced Distance Vector (DSDV). In this paper, we study and compare the performance of the following three routing protocols AODV, DSR and DSDV.

Several attacks, such as man-in-the-middle, black hole and DoS may target a MANET. Thus, the aforesaid assumption may lead to unpredicted consequences, namely, low network efficiency and high vulnerability to attacks. Trust management in MANETs is needed when participating nodes, without any previous interactions, desire to establish a network with an acceptable level of trust relationships among themselves. Trust management is also required in the collection and distribution of evidences to assess or maintain the levels of trust required for successful task completion. According to Denning [2], “Trust cannot be treated as a property of trusted systems but rather it is an assessment based on experience that is shared through networks of people.” As in real life, an entity has confidence on another entity without any previous experience in order to achieve their goals. These shared experiences lead to trust development and decays with time and frequency of interactions. The inherent freedom in self-organized mobile ad hoc networks introduces challenges for trust management. Some trust management models have been developed for wired networks but they are inapplicable to MANETs because of their dynamic topology and application scenario. In this paper, a trust management model is proposed for MANET with the objectives: a) to defend the network from any attacks from the malicious nodes and selfish nodes b) to improve the packet delivery ratio.

A Mobile Ad Hoc Networks (MANET) is a collection of mobile nodes that can communicate with each other using multi-hop wireless links without utilizing any fixed based- station infrastructure and centralized management. Each mobile node in the network acts as both a host generating flows or being destination of flows and a router forwarding flows directed to other nodes. With the popularity of ad hoc networks, many routing protocols have been designed for route discovery and route maintenance. They are mostly designed for best effort transmission without any guarantee of quality of transmissions. Some of the most famous routing protocols are Dynamic Source Routing (DSR), Ad hoc On Demand Distance Vector (AODV), Optimized Link State Routing protocol (OLSR), and Zone Routing Protocol (ZRP). In MAC layer, one of the most popular solutions is IEEE 802.11. At the same time, Quality of Service (QoS) models in ad hoc networks become more and more required because more and more real time and multimedia applications are implemented on the network. In MAC layer, IEEE 802.11e is a very popular issue discussed to set the priority to users. In routing layer, QoS are guaranteed in terms of data rate, delay, and jitter and so

A specific feature of the multiprocessor is the predictabil- ity of its performance. Packet based communication is used instead of simple time multiplexing, enabling a high band- width utilization. In Grünewald et al. (2005a) methods have been proposed to assign the protocol functions to processors and to estimate the resource consumption of the final map- ping. During the mapping either delay or energy consump- tion per packet can be minimized. An essential requirement for this methodology is that the upper bound for the latency of a packet can be calculated. As usual in NoCs, the packets are divided into data units of fixed size, called flits.

In this paper, a dynamic K-means algorithm to improve the routing process in Mobile Ad-Hoc networks (MANETs) is presented. Mobile ad-hoc networks are a collocation of mobile wireless nodes that can operate without using focal access points, pre-existing infrastructures, or a centralized management point. In MANETs, the quick motion of nodes modifies the topology of network. This feature of MANETS is lead to various problems in the routing process such as increase of the overhead massages and inefficient routing between nodes of network. A large variety of clustering methods have been developed for establishing an efficient routing process in MANETs. Routing is one of the crucial topics which are having significant impact on MANETs performance. The K-means algorithm is one of the effective clustering methods aimed to reduce routing difficulties related to bandwidth, throughput and power consumption. This paper proposed a new K-means clustering algorithm to find out optimal path from source node to destinations node in MANETs. The main goal of proposed approach which is called the dynamic K-means clustering methods is to solve the limitation of basic K-means method like permanent cluster head and fixed cluster members. The experimental results demonstrate that using dynamic K-means scheme enhance the performance of routing process in Mobile ad-hoc networks.

ZigBee is a communication protocol based on the IEEE 802.15.4 standard [3] for low rate energy efficient information exchange. The low power usage allows longer node life with small batteries and the mesh network topology provides high reliability (star and tree topology are also possible). The channel access can be obtained in two modes, i.e. non beacon and beacon mode. There are three types of devices: FFD (Fully Function Device), RFD (Reduced Function Device) and Network Coordinator (NC) that can be used in order to create a network for personal benefit of the users.