Finally P. Agrawal et al  proposed a technique for detecting chain of cooperating malicious nodes (blackandgrayhole nodes) inadhoc network. In this technique initially a backbone network of strong nodes (capable of tuning its antenna to short (normal) as well as to long ranges) is established over the adhoc network. Each strong node is assumed to be a trustful one. These trustful strong nodes detect the regular nodes (having low power antenna) if they act maliciously. With the assistance of the backbone network of strong nodes, the source and the destination nodes carry out an end-to-end checking to determine whether the data packets have reached the destination or not. If the checking results in a failure then the backbone network initiates a protocol for detecting the malicious nodes. For detecting malicious node strong node associated with source node broadcast a find chain message to the network containing the id of the node replied to RREQ. On receiving find chain message strong node associated with destination node Initialize a list GrayHole Chain to contain the id of the node replied to RREQ. It then instructs all the neighbors of that node to vote for the next node to which it is forwarding packets. If the next node id is null then the node is a blackhole node. Then the grayholeremoval process is terminated and a broadcast message is sent across the network to alert all other nodes about the nodes in GrayHole Chain to be considered as malicious. Else strong node will elect the next node to which replied to RREQ is forwarding the packets based on reported reference counts. Then again broadcast the find chain message containing the id of the elected node. The main disadvantages of this algorithm are the difference between the regular node and backbone node in the network in terms of power, antenna range which makes it unsuitable for all types ofmobileadhoc network. Also it is not proved that backbone network is optimal in terms of minimality and coverage. Algorithm will fail if the intruder attacks strong nodes because it violates the assumption that strong nodes are always trusted node.
The blackhole nodes are simulated in appropriate positions by making suitable modifications listed previously. The density ofblackhole nodes is also varied from 1% to 5% of the total nodes. The nodes move with a maximum velocity of 200 m sec −1 in a 1000×1000 sq.m simulated geographic area. Communication between a pair of nodes use Constant Bit Rate (CBR) type of application and the number of simultaneous communications is varied from low to high, in order to verify the operation of the proposed IDS in various traffic cases. Two-ray ground model is used to approximate the channel behaviour. Single path AODV establishes the path from the different sources to various destinations. The simulation scenarios of MANETs are carried out in the network simulator ns2.
A mobilead-hoc network is an autonomous network that consists of nodes which communicate with each other with wireless channel. Due to its dynamic nature and mobility of nodes, mobileadhocnetworks are more vulnerable to security attack than conventional wired and wireless networks. One of the principal routing protocols AODV used in MANETs. The security of AODV protocol is influence by the particular type ofattack called BlackHoleattack. In a blackholeattack, a malicious node injects a faked route reply claiming to have the shortest and freshest route to the destination. However, when the data packets arrive, the malicious node discards them. To preventing blackholeattack, this paper presents RBS (Reference Broadcast Synchronization) & Relative velocity distance method for clock synchronization process inMobilead-hoc Network for removalofcooperativeblackhole node. This paper evaluates the performance in NS2 network simulator and our analysis indicates that this method is very suitable to remove blackholeattack.
We now explain the grayholeattack on MANETs. The grayholeattack has two stages. In the first stage, a attacker exploits the AODV protocol to advertise itself as having a valid route to a destination node, with the intention of intercepting packets, even though the route is spurious. In the second stage, the node drops the intercepted packets with a certain probability. This attack is harder to detect than the blackholeattack where the attacker drops the received data packets with certainly. A grayhole may display its attacker behavior in different ways. It may drop packets coming from (or destined to) certain specific node(s) in the network while forwarding all the packets for other nodes. Another type ofgrayhole node may behave maliciously for some time duration by dropping packets but may switch to normal behavior later. A grayhole may also display a behavior which is a combination of the above two, thereby making its detection even more difficult (Pradip et al, 2010)
The GrayHoleattack has two phases. Initially, a malicious node exploits the AODV protocol to advertise itself as having a valid route to a destination node, with the intention of intercepting packets, even though the route is spurious. Next, the node drops the intercepted packets with a certain probability. This attack is more difficult to detect than the blackHoleattack where the malicious node drops the received data packets with certainty. A GrayHole may exhibit its malicious behavior in various techniques. It simply drops packets coming from (or destined to) certain specific node(s) in the network while forwarding all the packets for other nodes. Another type ofGrayHoleattack is a node behaves maliciously for some particular time duration by dropping packets but may switch to normal behavior later. A GrayHole may also exhibit a behavior which is a combination of the above two, thereby making its detection even more difficult.
Abstract- Mobileadhocnetworks have attracted attention lately as a means of providing continuous network connectivity to mobile computing devices regardless of physical location. An adhoc network is a collection of nodes that donot need to rely on a predefined infrastructure to keep the network connected. Such network may be interconnected to fixed network and serve as access network for mobile nodes. Hoiver the wireless neture adhoc network introduce new requiremnets to the effects that link breakage due to obility has on TCP performance. Through simulation, i show that TCP throughput drops significantly when nodes move, due to TCP’s inability to recognize the difference betien link failure and congestion. i examine the performance of the TCP protocol for bulkdata transfers inmobileadhocnetworks (MANETs). i vary the number of TCP connections and compare the performances of three recently proposed on-demand (AODV and DSR) and adaptive proactive (ADV) routing algorithms.
Like the RREQ, a RREP is only processed on first sighting and is discarded unless it has a greater destination sequence number than the previous RREP or the same destination sequence number but a smaller hop-count. The route expiration time is the time after which the route is considered to have expired and a new route discovery process must be undertaken. Source node sends packets via the first path it hears about. If it receives a later RREP which has either fresher information or a shorter hop-count, it swaps to that, discarding the original route information. When an active route link breaks, a Route Error (RERR) packet, with sequence number incremented from the corresponding RREP and hop-count of 1, is sent by the upstream node of the broken link to source node. Upon receipt of a RERR, source node initiates a new route discovery process if it still has packets to send to destination.
Wireless adhocnetworks, also called MobileAdHocNetworks (MANETs) are collections of autonomous mobile nodes or terminals that communicate with each other by forming a multi-hop wireless radio network. Each node in a MANET can act as both a host and a router to receive and forward packets and it can randomly move around, leave the network or switch off. Network wide broadcasting is a fundamental operation inadhocnetworks. In broadcasting, a source node sends a message to all the other nodes in the network. The advantage is that one packet can be received by all neighbors; the disadvantage is that it interferes with the sending and receiving of other transmissions, creating exposed terminal problem, that is, an outgoing transmission collides with an incoming transmission and hidden terminal problem that is, two incoming transmissions collide with each other. In general, broadcasting refers to a process of transmitting a packet so that each node in a network receives a copy
In the lowest ID clustering algorithm , a node with the lowest ID is chosen as a clusterhead. Each node is provided with a unique ID and it periodically broadcasts the list of its neighbor’s IDs, including itself. A node which only hears nodes with ID higher than itself is a clusterhead (CH). The lowest ID node that a node hears is its clusterhead, unless the lowest ID specifically gives up its role as a clusterhead when a node with a lower ID enters into the same cluster. This is a simple algorithm and the process of cluster formation is very fast. Also, the rate of change of clusterhead is low and hence the system performance is better in terms of throughput. On the other hand, the number of clusters may become undesirably high due to which the packet delivery delay may become excessive. Moreover, clusterheads with smaller IDs suffer from the battery drainage, resulting in short lifetime of the system. Figure 3 shows a schematic of the result of using lowest ID clustering. There are 11 nodes with unique IDs, which form a connected graph. After the Lowest-ID clustering algorithm is executed, three clusters are formed, as depicted by the dotted circles. The black colored balls inside each cluster represent the clusterheads (1, 5 and 3 in figure 5). The striped balls (6 and 7) that are within the communication range of two or more different clusters represent the gateway nodes and the empty balls are the member nodes.
The mobile nodes in MANET are located randomly and continuously changing their positions in network. Thus, the interconnections among mobile nodes are also changing frequently. Such networks are thus self-organizing and self- configuring and one does not require central management for configuration purpose. In MANET, all nodes can communication each other using the wireless links. Due to the characteristics of MANET like allowing access to servies anywhere, anytime ubiquitously without need of any physical devices or platform, it is mainly used in crisis management services, military areas, conference halls, classrooms, etc. Development of multimedia applications like video conferencing and video on demand is possible only because ofadhoc networking developments of MANETs.
The term MobileAdhocNetworks (MANETs) is used for the adhoc wireless local area networks (Adhoc WLAN) by the Internet Engineering Task Force (IETF) wherein the mobile nodes can communicate with each other directly without the requirement of support station . Due to their non dependence on the central communication point they can be quickly installed. MANETs can work either in isolation or as extension to a pre installed wired network . The MANETs can be used in the disaster situations such as earthquakes or hurricanes where infra structure facilities such as power and communication lines have been destroyed. They can also be used in planned military operations or in the battle field . Since, MANETs do not have centralized router that helps them in communication, therefore, each node has to act as a router, transmitter and receiver.
, , , , . According to our analysis, there are several difficult problems to reach the secure respect in these proposed AdHocnetworks protocols. First, it is the key distribution problem between nodes. Generally, the authors have all supposed that the nodes already shared a common key each other or obtained others' public keys in advance. Secondly, in the AdHocnetworks, the malicious node easily modifies the routing information or masks other nodes to forge routing information. How to protect the routing information and authenticate the identity is another difficult problem. In some papers, the authors do not particularly describe about their attack models, and not mention how much the influence degree is while the malicious nodes attack the network. Therefore, I need a secure scheme to solve these problems, and a completely attack scenarios analysis and simulation. I will propose a secure routing protocol for AdHoc network. Then, I will check this scheme whether it reaches our secure demand. At the same time, I will simulate two attack scenarios to this proposed scheme to verify the influence on AdHoc network.
The delay performance of wireless networks, however, has largely been an open problem. This problem is notoriously difficult even in the context of wire line networks, primarily because of the complex interactions in the network (e.g., superposition, routing, departure, etc.) that make its analysis amenable only in very special cases like the product form networks. The problem is further exacerbated by the mutual interference inherent in wireless networks which, complicates both the scheduling mechanisms and their analysis. Some novel analytical techniques to compute useful lower bound and delay estimates for wireless networks with single hop traffic were developed. However; the analysis is not directly applicable to multi-hop wireless network with multi hop flows, due to the difficulty in characterizing the departure process at intermediate links.
EncryptOnClick for AES Algorithm with 256 bit, Blowfish 2000 for Blowfish algorithm and Kryplite for DES algorithm. Based on the input which is distance and size, time that used to send data to receiver and throughput could be calculate. All of these calculation done in the MATLAB programming and the output produces time of data transfer. Based on the gained results the authors recommended choosing AES to achieve fast delivery of data and high throughput, and choosing Blowfish algorithm when larger size of data sending with smaller transmission rate. Kashani and Mahriyar in  analyzed video streaming characteristics inAdhocnetworks using several cryptography algorithms. The authors presented an application setup for secured video streaming inAdhocnetworks. Public key infrastructure approach was chosen to provide authentication at the network layer. They proposed a fully distributed certification authority (CA) for Optimized Link State Routing (OLSR) based Adhocnetworks. The initial assumption was that the network contains predefined special nodes called shareholders. Shareholders can generate partial signatures. A node joining the network, can obtain a certificate only if it receives at least k partial signatures form k different shareholders ,a shareholder offering service can be identified from the broadcasted HELLO messages. On the other hand, different cryptography schemes were implemented and analyzed in the study; RC4, 3DES, AES-128, AES-256, Salsa20-128 and Salsa20-256 and the time required to encrypt different sizes of data were adopted as a performance metric. The results showed that for RC4, 3DES, AES-128, AES-256, Salsa20-128 and Salsa20-256 took less than 1500 ms to encrypt the 1 MB binary file. 3DES consumes the largest encryption time followed by Salsa20-256, Salsa20-128, AES-256, AES-128 and RC4 respectively.
In this paper, a dynamic K-means algorithm to improve the routing process inMobileAd-Hocnetworks (MANETs) is presented. Mobilead-hocnetworks are a collocation ofmobile 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 inMobilead-hocnetworks.
The overhead of typical BSS (Basic Service Set) setup is too much expensive for both safety and non safety applications. A vehicle approaching a road side station that offers, suppose services like local information, it can hardly afford few seconds that are required in typical WLAN connection setup, because due to the dynamics of vehicle the total time it stay in the range will be too short then waiting for connection .Analyzing this factor WAVE standard introduced WBSS (WAVE BSS), which is the enhancement of BSS type. In WBSS environment, an STA forms a WBSS by first transmitting an on demand beacon. The WAVE station uses that demand beacon, which uses the well known beacon frame and needs not to be repeated every so often, to advertise a WAVE BSS unlike BSS. Upper layer mechanism above the IEEE 802.11 creates and consumes such advertisements. It contains all the necessary information need by the receiver station to understand the services offered in the WBSS in order to decide whether to join the WBSS and if needed configure itself into a member of the WBSS. In other words if station decides to join will need only WAVE advertisement for complete joining process with no further overhead.
A concise review of existing TCP variants and their appropriate algorithms are evaluated and define that which protocol is appropriate for the packets, for the utilization of link in the congestion network and the failure of the link causes the disorder inAd-hoc network because old TCP deals with each packet losses only due to jamming not from the failure of link. This review is achieved and analyzed from the variants of TCP for instance, TCP Tahoe; TCP Reno; TCP New Reno; TCP West-wood; TCP Lite; TCP Sack; TCP Fack and TCP Vegas. Some protocols demonstration their best uses and some shows bad responsiveness to network varying situations and utilization of the network. Even though there are used several protocols and mechanisms but not a single mechanism can be used that can reduces and eliminating the congestion and unreliable network’s nature. In solution for the network’s problems of TCP protocol, each variant of TCP has its specific advantages
networks. They progress in disseminated and contained method, and are capable to scrutinize and acclimatize to alterations in transfer prototypes. On the other hand, alterations in MANETs are greatly severe: Besides disparities in transfer, mutually topology and amount of nodes can alter incessantly. Additional complexities are created by the restricted realistic bandwidth of the common wireless means: even though the information speed of wireless transmission is elevated, algorithms utilized for medium access control, like IEEE 802.11 DCF (a large amount utilized universally in MANETs), produce a huge transparency mutually in provisions of manageable packets and delay, reducing the efficiently accessible bandwidth. Confronts of autonomic organizing are consequently more higher, and novel proposing is essential to assure still the fundamental network tasks.
Our main concern in this paper is to introduce a model that increases the MANET life time through load balancing multipath new technique representing parallism in sending data using 100% disjoint multiple paths (all selected paths sending data at the same time). We applied the load balancing concept to distribute data packets on the generated disjoint paths to solve the overloading problem and to prevent node starvation in next few sections. We will divide LBPRP proposed protocol into three parts, first part describe how can we select 100% disjoint paths (section 3.1), second part distributing traffic among paths to achieve load balancing in sending data (section 3.2) and if one of paths is broken we will use path maintenance in third step (section 3.3).
The Ad-Hoc On-Demand Distance Vector routing protocol is a r eactive routing protocol. AODV protocol is a combination of Dynamic Source Routing (DSR) and DSDV protocol . It is a distance vector routing protocol and is capable of both unicast and multicast routing . It will maintain the routes only between the nodes which need to communicate. The routing information will be maintained as routing tables in each node. A routing table entry expires if it has not been used or reactivated for pre- specified expiration time. When a source node wants to send the packet to a destination node then the entries in the routing table will check whether there is a current route to the destination node or not, if there is a route then the packets will transmit to destination node in that path . If don’t have any valid route, then the route discovery process will be initiated. For route discovery AODV is using Routing Request (RREQ), Routing Reply (RREP) Packets . The RREQ packet containing the source node IP address, source node current sequence number, the destination node sequence number and broadcast ID . The advantage of AODV is that it creates no extra traffic for communication along the existing link but requires more time to establish a connection. It is simple and doesn’t require much memory or calculation.