An Enhanced Selective Forwarding Scheme for realtime applications in MANETs

106. An Enhanced Selective Forwarding Scheme for realtime applications in MANETs 

ABSTRACT:

In MANETs, flooding-based route discovery is usually preferred in order to set up the route with reliability between transmission pair. However, this approach may cause a serious contention in transmission between adjacent nodes and a considerable amount of control packets. In addition, most of ad hoc routing protocols establish the route with minimum hop count. Consequently, the performance of ad hoc routing protocol is considerably affected by link (or route) duration since the network comprises the nodes with unrestricted mobility and constrained range in transmission. This paper proposes a novel routing algorithm that aims to i) minimize routing overhead in route discovery procedure, and ii) guarantee a reliable and fast packet delivery between source and destination, especially in providing real-time applications over MANETs. To achieve this objective, we introduce Relay Region within the transmission range of nodes in order to select optimal next relaying nodes for supporting specific application requirements in route discovery procedure. The proposed Relay Region is defined by the limited distance progress in transmission to next relaying node in order to maintain the established route for an arbitrary length of time (i.e., route duration) while meeting packet delivery reliability and delay constraints. The simulation results showed that the proposed scheme can significantly improve the performance of packet delivery ratio and packet delivery latency, reducing transmission redundancy in route discovery procedure.

EXISTING SYSTEM:

·        In  RPF and MSTF are the existing techniques in Packet forwarding mechanism in mobile ad hoc networks. In these techniques, the average no of hops taken by the system to identify the destination node is more. This creates overall delay in the system performance.

·        In RPF, the next SN to forward the search packet is chosen randomly from the list of unchecked SNs, while in MSTF, the packet traverses the SN nodes which are connected via a constructed minimal spanning tree (MST). For this, all SNs must send their routing tables to a randomly chosen SN at predetermined intervals (2 seconds in the simulations).       

PROPOSED SYSTEM:

• The idea behind this project Minimum Distance Packet Forwarding is to use routing table information for visiting nodes in the order of shortest distance (hop counts).
• The assumption that the set of nodes that hold the search information is known to all nodes in the wireless network, and to refer these nodes as the search nodes, or SNs.

HARDWARE SPECIFICATION

Processor Type                 :                  Pentium -IV

Speed                                :                  2.4 GHZ

Ram                                  :                  128 MB RAM

                  Hard disk                          :                  20 GB HD

SOFTWARE SPECIFICATION

                  Operating system     :  Windows - XP

Tools                        :  OMNET ++

OPERATING ALGORITHM

Step 1: On initialization, Search Nodes (SN) are formed randomly and each   SN aware of other SN position. SN maintains the detail of the Cache node and the application it holds.

Step 2: The Client Node which want to get any service (application) from external resource, before requesting the external resource it forward the request to its nearest Search Node.

Step 3: If the Search node could find the requested service in its detail then it    forward the request to its nearest Search Node. If the service found in any Search Node go to step 4 else Step 5.

Step 4: The Search Node forward the request to the Cache Node holding that service. The Cache node will reply with the requested service to  the  Client Node.

Step 5: The Final Search node will send the request to External resource and from which the reply for the service request is sent back the Client Node.

Step 6: The Client Node will get its requested service and it update the service detail which it got on its nearest Search node, so that it will be available for someother nodes on searching this service.

MODULES IN THIS PROJECT

                    This project consists of three modules :

i)                    Acquiring the required data to the client from the  search nodes.

ii)                   Desired Data accessing from internal network nodes and

iii)                 Data accessing from external network nodes .

Module 1:  Acquiring the required data to the client from the  search nodes

i)                    The client uses the information in the routing tables to send  its request to the nearest SN .

ii)                   If an SN does not have the requested data, it again  forwards the request to the nearest unvisited SN .

iii)                 This Process Should be repeated within the network , until the requested data found .

Module 2:  Desired Data accessing from internal network nodes

i)                    During the searching of data , if data match is occurred with the reference of the stored cached query , the request of the client is forwarded to the CN that stores the result .

ii)                   CN sends the result to the client whose address is found in the forwarded packet .

Module 3:   Data accessing from external network nodes

i)                    If no match is found in the SNs, then the request forwards to the data server via the access point .

ii)                   The server retrieves the request and sends the resultant data directly to the client node (i.e). particular SN.

REFERENCE:

Do-hyeon Lee, Jun-ho oh, Jae-il Jung, “An Enchanced Selective Forwarding Scheme for real time applications in MANETs”, IEEE 2011