Ensuring Reliable and Stable Communications in Mobile Ad-Hoc Networks

Quality of service (QoS) and security have been considered as two competent units to govern and administer end-to-end traffic across network. A mobile ad hoc network (MANET) is a type of wireless communication, every node can act as a router or base station. Secure QoS-based routing is an important problem in MANET. A hierarchical key ranking (HKR) model is presented here for secure group communications in MANETs. To enhance the security, one-to-one random mapping is performed using hash-based message authentication code (HashMAC). Due to the dynamic nature and topological changes in MANET, group safeguarding is efficiently accomplished. For secure group communication and efficient QoS routing in MANET, a sector key (SK) is shared among group members to encrypt group messages which is obtained using secured message authenticated code (SMAC). The primary design is to include the group members in sector to vigorously contribute to the security of the multicast group, as a result dropping the communication and calculating load on the source. Experimental evaluation is done to estimate the performance of the proposed secure QoS routing and communication using hierarchical key ranking [SRHKR] in MANET in terms of delivery rate, security level, delay.

Cognition capability has been seen by researchers as the way forward for the design of next generation of Mobile Ad Hoc Networks (MANETs). The reason why a cognitive paradigm would be more suited to a MANET is because MANETs are highly dynamic networks. The topology may change very frequently during the operation of a MANET. Traffic patterns in MANETs can vary from time to time depending on the need of the users. The size of a MANET and node density is also very dynamic and may change without any predictable pattern. In a MANET environment, most of these parameters may change very rapidly and keeping track of them manually would be very difficult. Previous studies have shown that the performance of a certain routing approach in MANETs is dependent on the size of the network and node density. The choice of whether to use a reactive or proactive routing approach comes down to the network size parameter. Static or offline approaches to fine tune a MANET to achieve certain performance goals is hence not very productive as a lot of these parameters keep changing during the course of operation of MANETs. Similarly, the performance of MANETs would improve greatly if the MAC layer entity could operate in a more flexible manner. In this paper we propose a cognitive MANET design that will ensure that all these dynamic parameters are automatically monitored and decisions are based on the current status of these parameters.

Now a days, mobile users like to use their own consumer electronic devices anywhere and at anytime to access multimedia data. Consumer electronic devices have evolved depending on user needs. Users want to use compact and portable devices such as cellular phones, laptop computers, Personal Digital Assistants (PDAs), etc. anywhere and at anytime to download multimedia data or to access realtime traffic. The mobile Ad Hoc networks have several salient characteristics, such as Dynamic topologies, Bandwidth-constrained, Variable capacity links, Energy-constrained operation and Limited physical security. Due to these features, mobile Ad Hoc networks are particularly vulnerable to denial of service attacks launched through compromised node. The communication in mobile AdHoc networks comprises of two phases, the route discovery and the data transmission. In a hostile environment, adversarial nodes can try to disrupt communication in both the two phases. However, consumer electronic devices generally operate on limited battery power and therefore are vulnerable to security threats like data flooding attacks. Flooding attack is a novel and powerful attack against on-demand Ad Hoc routing protocols. At present, FAP (Flooding Attack Prevention) is the single scheme proposed to resist such attack. But it may not give quality of service. In this paper, we present a Period Based Defense mechanism against data flooding attack in wireless AdHoc network. This is the new technique to defend the flooding attack. This scheme is based on the periods and uses a blacklist to efficiently prevent the data flooding attack. The main aim of this paper is to enhance the throughput of burst traffic. As a result of which, many data packets are forwarded at a high rate for the whole duration. The simulation results show that the proposed scheme enhances the throughput of burst traffic.

6 - Current vulnerabilities, challenges and attacks on routing protocols for mobile ad hoc network: a review

Wireless Sensor Networks (WSN) utilizes more nodes to forward messages and information from source node to destination node and these nodes are battery-powered devices. Thus, Energy saving is always vital role of Routing Protocols which need to maximize the lifetime of WSN. Mobile ad hoc networks (MANET) are self-starting and self-constructing multichip wireless networks in which, the assembly of the system deviates vigorously. This is mainly due to the mobility of the nodes. The nodes in the network not only act as hosts but also as routers that route data from other nodes in network. MANETs require an efficient routing protocol that achieves the quality of service (QoS) mechanism. They are not considering the mobility as one constraint for those problems. Because, mobility of nodes causes frequent link failures and high error rates, so it makes difficult to maintain the desired QoS in the network. To overcome those problems, we propose mobility aware routing protocol for MANET using hybrid optimization (MARP-HO) algorithm, which maximizes the QoS in data transmission. The proposed routing protocol comprises of two phases. The clustering process consists of cluster formation and cluster head (CH) selection. First, the energy efficient clustering is done by improved animal migration optimization (IAMO) algorithm. Then, we gather multiple constraints are energy consumption, received signal strength, mobility and cooperative rate from each cluster member. The gathered constraints used to compute the node cost of each cluster member, here the highest cost node act as CH of cluster. Second, we compute routing path between source–destination using improved ant colony optimization (IACO) algorithm. The proposed MARP-HO routing protocol is compared with existing state-of-art routing protocols in terms of energy consumption, delivery ratio, loss ratio, link stability, delay, network lifetime, number of dead nodes and throughput.

In the last two decades, Multi-Cast schemes in mobile ad-hoc networks have been widely studied and lots of research results have been put into use and changed our everyday life. However, packet loss for Multi-Cast schemes in mobile ad-hoc networks has not been well studied yet. The influence of node density and relay schemes on packet loss is not clear. Thus, we study the packet loss problem for Multi-Cast schemes in MANETs in this paper. First, we present a general Multi-Cast probabilistic model to get a better understanding of the packet loss problem. Second, based on the general model and Chernoff Bounds, we prove that the up'er bound of the general packet loss for Multi-Cast is Ω(me <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">- 2</sup> ), where n is the node number and m denotes number of hops. Thus we can conclude that large node density decreases the packet loss rate by exponential factor, and bigger hops increase packet loss rate linearly. In addition, we present a reliable Multi-Cast protocol(RMP). Through an ACK Aware Tree to complete packet acknowledgement and repair host selection, RMP is able to minimize the impact of packet loss on the Multi-Cast throughput in the simulation.

Background:AMobileAdHocNetwork (MANET) consistsofmany independentnodes that operate over awireless topology with numerous Quality of Service (QoS) requirements. So, a robust routing protocol that also provides QoS parameters to its different range of applications is needed. Various network parameters like node density, node mobility, field size etc. also effects the QoS parameters of MANETs. Methods: The traditional reactive routing protocols do not have any backup route in case of a node failure and hence are not effective for MANETs. Ad Hoc on Demand Distance Vector Backup Routing (AODV BR) protocol performs better than traditional routing protocols but is not effective when the backup route fails. So, to counter this problem, the authors had proposed AODV nth BR that keeps on providing backup routes when multiple nodes fail and hence successfully transfers the data to the destination. The nodes for backup routing are selected based on their distance from the failed node and energy efficiency. Results: In this paper, the performance of AODV nth BR has been compared with AODV, DSR and AODV BR protocol under varying node density (nodes 20, 60,100) and node mobility conditions (5m/s, 20m/s, 50m/s). The values for Packet Delivery Fraction (PDF) for 60 nodes at speed 20m/s in case of AODV nth BR protocol after 6000 rounds is 0.3054. Comparatively, value of AODV BR is 0.2664, AODV is 0.1936 and DSR is 0.1056. QoS performance is measured in terms of end to end delay, packet delivery fraction and lifetime of devices and it has been shown through simulated results that AODV nth BR protocol gives better output than traditional routing protocols. Conclusion: From the simulated results explained in detail in the paper, it has been observed that route after link breakage is found to be best with AODV nth BR protocol and this can be clearly seen in the QoS parameters obtained.Keywords: AODV BR, AODV nth BR, MANETs, Node Density, Node Mobility

Multicast communication in mobile adhoc networks is challenging due to its inherent characteristics of infrastructure-less architecture with lack of central authority, limited resources such as bandwidth, time, energy and power. Many emerging commercial and military applications require secure multicast communication in adhoc environments. Moreover, mobile nodes are often power constrained so that energy conservation is also an important issue on multicast key distribution. This paper evaluates the energy conservation of a new approach of multicast key distribution called cluster based multicast tree algorithm with multicast destination sequenced distance vector routing protocol to provide reliable and efficient energy conservation of multicast key distribution. Simulation results in NS2 accurately predict the performance of proposed scheme in terms of energy consumption and end to end delay rate under varying network conditions.KeywordsMobile Adhoc NetworksMulticastKey DistributionEnergy conservation

Problem statement: In Mobile Ad hoc Networks (MANET) routing protocols, we require a network-level or link layer security. Since without appropriate security provisions, the MANETs is subjected to attacks like network traffic, replay transmissions, manipulate packet headers and redirect routing messages. In order to address these needs, a policy based network management system that provides the capability to express network requirements is required. Approach: In this study, we propose a policy based scheme for combined data security which focuses mainly on three policies: Integrity, authentication and Confidentiality. For providing security not only to data, but also for routing information, we calculate the trust indexes of the nodes and the route is selected according to the trust value which improves integrity. Then in order to provide authentication, we propose a Distributed Certificate Authority (DCA) technique in which multiple DCA is required to construct a certificate. Next we propose an RSA based novel encryption mechanism in order to provide Confidentiality among the nodes. Thus, the desired level of security is provided by the system based on the policy of the user by executing the corresponding security modules. Results: By simulation results, we show that this scheme provides a combined data security in MANETs and can be used efficiently. Conclusion: Our proposed combined data security policy provides complete protection for the data in MANET communications.

Flow control, end-to-end (EED) delay, throughput, and energy consumptions are important factors of real-time and multimedia communication in mobile ad-hoc networks (MANET’s). It has a characteristic of the dynamic flow of data communication among the various users without using wired technologies. Due to this dynamic structure of MANNETS, most of its energy is consumed in route searching and packet retransmission. In addition, a problem of energy consumption may also occur due to network congestion and traffic flow control. In general, UDP is used for real-time communication but this protocol is unable to control the traffic flow properly. Therefore, a new protocol is developed for this purpose called datagram congestion control protocol (DCCP) used in those networks, which has an increasing number of multimedia traffic, and real-time flow. In this research work, major performance metrics with the issue of power usage of the TFRC and TCP like DCCP protocols are evaluated.

A MANET (Mobile Ad-Hoc Network) is composed of mobile, autonomous, wireless nodes that could be connected at network edges to that of fixed wired internet. The ad-hoc network does not need infrastructures that are required for other wireless networks. The term infrastructure includes need of base stations, routers etc. The network execution ought to be supported up by protecting collaboration among various nodes and it is finished by essential mechanisms. In further, most proficient routing protocols are utilized to route the packets to the destination from the source by the method of routing process. In MANET, there are various kinds of routing protocols and every one of them is associated with systematic circumstances. This paper focuses on designing a new routing protocol which considering minimum number of nodes for routing and select optimal route. This protocol also concentrates clustering as well as security considerations in order to provide tenable and proficiency routing.

A mobile ad hoc network (MANET) poses significant challenges such as route failure and end-to-end delay due to the decentralized nature of mobile ad hoc wireless networks, mobility of devices, and resource constraints. Motivated by this, in this work, a new routing protocol by implementing intelligent reflecting surfaces (IRSs) in MANET, called MRIRS, is proposed. The developed MRIRS investigates the role of IRS as an intermediate node which helps not only for multi-flow multi-path routing even in non-line-of-sight (NLoS) scenarios but also supports delay minimization in the route discovery phase and helps with interference-avoiding channel assignment to the primary users (PUs). Comparison in terms of packet delivery ratio (PDR) and end-to-end delay (PD) averaged on 40 topologies based on the same source and destination pair with 3 flows shows that MRIRS has an 8% improvement in PDR and 800 msec improvement in PD. In environments with 8 m/s average node speed, MRIRS shows 114.88 kbps improvement in terms of throughput where 15.97% link failure is recorded on average. In environments with 16 m/s, link failure is around 24% where it is almost 98% for other routing protocols.

Wireless networking is an emerging technology that allows users to access information and services regardless of their geographic position. Further, the development of ubiquitous mobile computing devices has also raised increasing demand in sharing streaming video and audio in various applications like video conferencing, video chat, etc. along with simple file transfers. A community Internet Engineering Task Force [1] is already working on development of several routing protocols for mobile ad hoc networks. However, the performance of each routing protocol is different from each other in different scenarios. Hence, the main investigation done in this paper is of the discrete feature and routing in MANET. The main issue of MANET is the breakage of link at certain moment and re-generation of link at certain state as it consists of routers which are mobile in nature i.e. are independent to roam in an arbitrary motion. Considering the above real time applications, this paper focuses on performance analysis of routing protocols based on their node density and traffic pattern for a fixed size campus area. This paper evaluates four routing protocols i.e. AODV, DSR, OLSR and TORA protocols for wireless mobile ad-hoc networks based on performance for different node density for real-time traffics. The performance metrics are taken as delay, network load and throughput. The comparison analysis is carried out about these protocols, and in the last the conclusion is presented to determine the better routing protocols for particular scenarios. All the experimental set up and simulations is done using OPNET v14.5 Simulator.

Ad Hoc wireless networks are different from traditional cellular networks which have many striking features for effective communication that are much absent in ad hoc wireless networks. The basic objective of effective communication is to pass the information from source to destination with the view on energy consumption, reliability, security, cost factor and so on. Energy efficient routing plays a primary role to sustain the Mobile Ad hoc NETwork (MANET) that defined as the kind of wireless networks that make use of multi-hop wireless links with possessing the dynamic capability of functioning without the back of any fixed infrastructure and each node must act as a router and data packet forwarder. Moreover batteries used by MANETs have limited power and so restricted processing power, which in turn confines services and applications that can be supported by each node. So, Energy management is inevitable in MANET. Here; the ultimate focus is on the role of energy factor and in parallel on all other relevant factors are concentrated at integrated approach for offering valuable communication between every node in the MANET.

In mobile ad hoc networks (MANETs), the efficient energy-efficient cluster head selection (EECHS) is a significant issue. When an appropriate cluster head (CH) is chosen, MANETs'''' energy efficiency improves. Clusters are built in MANETs to facilitate communication between nodes. The EECHS problem has been addressed using a variety of clustering strategies, including distributed clustering and cluster-based routing. However, these approaches require high overhead and complexity, leading to suboptimal performance. Therefore, it is necessary to develop an algorithm that can select the best CH to facilitate efficient energy-efficient communication in MANETs. In this regard, the Firefly Algorithm (FA) has been proposed as an effective approach to solving the EECHS problem. FA is a type of swarm intelligence-based meta-heuristics algorithm inspired by the behavior of fireflies. FA is a simple and efficient optimization method that can be used to select the best CH in MANETs. The method has a number of benefits, including enhanced convergence rate and local search functionality. FA is also computationally effective and can adapt to shifting network conditions. This essay offers a thorough evaluation of the literature on the use of FA in MANETs to address the EECHS. Along with comparisons of their performances, a thorough examination of the suggested methodologies and algorithms is offered. Last but not least, various difficulties and potential research paths pertaining to the usage of the FA are explored.