7/31/2019 Adhoc Internet

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MINIMIZING FORWARDING NODES IN WIRELESS AD HOC

NETWORK BROADCASTING FOR CONNECTING WIRELESS

NETWORKS WITH INTERNET

M.Murugesan Dr A.Krishnan

Abstract:

Prior to wireless networks, setting up a computer network often required running many cables

through walls and ceilings in order to deliver network access to all of the network-enableddevices in the building. With the advent of the Wireless Networks, network users are now able to

add devices that access the network with few or NO cables. An Ad-Hoc network uses a

connection between two or more devices without using an access point: the devices

communicate directly. An Ad-Hoc network is used in situations such as a quick data exchange a

because it is easy to set up and does not require an access point. Internet traffic will converge to

the nodes with direct internet connection, potentially congesting these nodes. A mobile ad hoc

network enables wireless communications between participating mobile nodes without the

assistance of any base station. When an ad hoc network is connected to the Internet, it is

important for the mobile nodes to detect available gateways providing access to the Internet.

Therefore, a gateway discovery mechanism is required

Two nodes that are out of one anothers transmission range need the support of

intermediate nodes which relay messages to set up a communication between each other.

Network wide broadcasting is a fundamental operation in ad hoc networks. In broadcasting, a

source node sends a message to all the other nodes in the network. Many data forwarding

operations (e.g., the route discovery process in on-demand routing protocols) involve the

broadcasting of packets, which incurs considerable collisions in ad hoc networks..The broadcast

operation, as a fundamental service in mobile ad hoc networks (MANETs), is prone to the

broadcast storm problem if forwarding nodes are not carefully designated. The objective of

reducing broadcast redundancy while still providing high delivery ratio is a major challenge in

MANETs. In this paper, we propose a simple reliable broadcast algorithm to find the gateway

node to connect with the internet, which takes advantage of broadcast redundancy to improve the

delivery ratio. Among the nodes within the transmission range of the sender, only selectedforwarding nodes retransmit the broadcast message. To provide full reliability for all forwarding

nodes ,the transmission of the forwarding nodes are received by the sender as the confirmation of

their reception of the packet. The non forwarding nodes send explicit ACK to the sender after

receiving the message from the sender1-hop neighbors of the sender do not acknowledge the

reception of the broadcast. If the sender does not detect all its forwarding nodes retransmissions,

it will resend the packet until the maximum number of retries is reached. The proposed broadcast

algorithm provides good broadcast delivery ratio with low overhead and minimum latency.