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.