Ad-Hoc Networks Seminar
Abstract: Wireless ad hoc networks (also referred to as packet radio networks and multi-hop radio networks) consist of mobile nodes communicating over a shared wireless channel. Contrary to cellular networks, where the nodes are restricted to communicate with a set of carefully placed base stations, in wireless ad hoc networks there are no base stations; any two nodes are allowed to communicate directly if they are close enough, and nodes must use multi-hop routing to deliver their packets to distant destinations. The lack of wired infrastructure, the nature of the wireless channel, and the mobility of the nodes create many challenging problems in the link, network, and higher layers of the network protocol stack. On the other hand, the lack of wired infrastructure and their topology make these networks ideal for many applications, from personal area networks, to search and rescue operations, to massive networks of millions of sensors. It is therefore expected that, once all the technological issues are solved, wireless ad hoc networks will become an integral part of our society's communication network infrastructure.
1.1 Ad hoc networks
Recent advances in portable computing and wireless technologies are opening up exciting possibilities for the future of wireless mobile networking. A mobile ad hoc network (MANET) is an autonomous system of mobile hosts connected by wireless links. Mobile networks can be classified into infrastructure networks and mobile ad hoc networks according to their dependence on fixed infrastructures. In an infrastructure mobile network, mobile nodes have wired access points (or base stations) within their transmission range. The access points compose the backbone for an infrastructure network. In contrast, mobile ad hoc networks are autonomously self-organized networks without infrastructure support. In a mobile ad hoc network, nodes move arbitrarily, therefore the network may experiences rapid and unpredictable topology changes. Additionally, because nodes in a mobile ad hoc network normally have limited transmission ranges, some nodes cannot communicate directly with each other. Hence, routing paths in mobile ad hoc networks potentially contain multiple hops, and every node in mobile ad hoc networks has the responsibility to act as a router.
Mobile ad hoc networks originated from the DARPA Packet Radio Network (PRNet) and SURAN project. Being independent on pre-established infrastructure, mobile ad hoc networks have advantages such as rapid and ease of deployment, improved flexibility and reduced costs.
Multicasting is the transmission of datagrams to a group of hosts identified by a single destination address and hence is intended for group-oriented computing. In MANETs, multicasting can support a variety of applications such as conferences, meetings, lecturers, traffic control, search and rescue, disaster recovery, and automated battlefield. In ad hoc networks, each host must act as a router since routes are mostly multihop.
Figure 1-1 shows an example of using MANET to hold conference meeting in a company. A group of mobile device users set up a meeting outside their normal office environment where the business network infrastructure is missing. The mobile devices automatically construct a mobile ad hoc network through wireless links and communicate with one another. The figure shows topology of the network and the available wireless links at a certain time. Suppose Susan wants to send data to Jerry. According to the network topology, Jerry’s PDA is not in the immediate radio transmission range of Susan’s laptop. The routing software on Susan’s laptop finds a route Susan
Ad Hoc NetworksorWireless LAN
Types of Wireless Networks
Infrastructure based (Cellular Network).
Infrastructure less Network (Ad hoc
What is Ad Hoc Network ?
Characteristics of an Ad-hoc network
Collection of mobile nodes forming a temporary network
Network topology changes frequently and
No centralized administration or standard
Host is also function as router
A route between two nodes is found by sending an Route Request
Route Request builds a source route on every path through the network
First Route Request to arrive is accepted; target responds on that path and tells initiator what the source route is
Source route is used on subsequent data traffic
Creating wireless Ad Hoc network in window xp
To create a new ad hoc network open Control Panel then Network Connections, or right click on the wireless icon in the system tray (by the clock).
Click open network connection.
Click on the Wireless Network tab then the add button.
A new window will appear. Give your network a name, and check the two boxes near the bottom.
Connecting the Ad Hoc NEtwork
Open Network Connections (via Control Panel or the wireless icon) and select View Wireless Networks. The following window will appear.
You should see the ad hoc network as a computer-to-computer network. You may have to refresh the list.
Click on Change advanced settings. On the new window, click on the Wireless Networks tab, then advanced.
Set your tcp/ip i.e. 192.168.0.12
Set other nodes tcp/ip
The two tcp/ip should be different.
Open “run” from start button.
Type “ping” (ping 184.108.40.206) and the other nodes tcp/ip.
If it provides reply, you are connected to the node and can share your data with other node.