Ms. Priyanka Chavda FYMCA, [08MCA04]

 

Introduction to Ad-hoc networking:

Ad-Hoc Networking is a kind of wireless networking which is a self-configuring network of mobile routers connected by wireless links. The network is Ad-Hoc because each node is willing to forward data for other nodes, and so the determination of which nodes forward data is made dynamically based on the network connectivity.The term ad hoc network can also refer to an independent basic service set (IBSS).Connections are possible over multiple nodes (multihop ad-hoc network).Mobile ad-hoc networks became a popular subject for research as laptops introduced. Mobile communication in wirefree environment. The connection is established for the duration of one session and requires no base station. Devices may search for target nodes that are out of range by flooding the network with broadcasts that are forwarded by each node.Access point manages communication among other nodes.Mobile ad-hoc networking known to be ”MANET”. Routing protocols provides stable connections even if nodes are moving around.Sony’s Play station Portable uses ad-hoc connections for wireless multi-player gaming.New networks can be constructed by the combination of computation, communication and reputation.

Components of Ad-hoc Networking

1. Public switched telephone network (PSTN)
   Traditional landline network that mobile wireless systems connect with to complete calls.
2. Mobile Telephone Switching Office (MTSO) The central switch that controls the entire operation of a    cellular system.
   It is a sophisticated computer that monitors all cellular calls, tracks the location of all cellular-equipped    vehicles traveling in the system, arranges handoffs, keeps track of billing information, etc.
3. Cellular Base Station (cell site)
   The transmission and reception equipment, including the base station antenna, which connects a cellular    phone to the network. Also called a cell site.
4. Mobile subscriber unit (MSU)
   Mobile subscriber unit uses Mobile Identification Number (MIN) which uniquely identifies a mobile unit    within a wireless carrier's network.

Ad-hoc routing protocol

It controls how nodes come to agree which way to route packet which contains the control information, error detection and user data between computing devices in a mobile ad-hoc network.” Packet radio” network (PRNETS) is digital data transmission used to link computers through packet switching between network nodes, which allows multiple virtual circuits to coexist on a single radio channel.” Service discovery” enables users, network devices and applications to seek out and find other user, network devices and applications, in a friendly and easy way. Protocol used is “Service Location Protocol”(SLP). Mechanism named OLSR (Optimized Link State Routing) protocol is used to response the client’s services.

Manet Working:

Each mobile uses a separate temporary radio channel to talk to the cellsite.The cellsite talks to many mobile at once, using one channel per mobile.Channels use a pair of frequencies for communication (forward link to reverse link).Radio energy dissipates over distance so mobile must stay near base station to maintain communication.The cellular radio equipment (base station) can communicate with mobiles as long as they are within range.These protocols fall into two categories:

Re-active routing protocols:
Pro-active routing protocols:

Does not take initiative for finding routes
Establishes routes “on demand” by flooding a query. Pros and cons:
Does not use bandwidth except when needed (when finding a route).
Much network overhead in the flooding process when querying for routes.
Initial delay in traffic.

Routes are set up based on continuous control Traffic.All routes are maintained all the time. Constant overhead created by control traffic.Routes are always available

Benefits of ad-hoc networking:

Rapidly deployable, self-configuring. No need for existing infrastructure.Wireless links. Nodes are mobiles and topology can be very dynamic.Manet can be standalone network or it can be connected to external network (Internet).

Domains where ad-hoc networking are used:

Ad-hoc connectivity between two wireless devices

If both computers have wireless capabilities, then a connection can be setup to connect them through the air. This type of wireless networking is also known as "Adhoc connection"

An assumption is made that you have already installed the wireless adapters or cards on the computers and they are working well. For the sake of simplicity, the two computers will be called node1 and node2 respectively.

ON "node1"

Right-click "My Computer", click "Properties"
Click "Computer Name" Tab
Click "Change"
A window should pop-up. Specify a name for the computer.
Click "Workgroup" and specify a name. (We will call the computer DAD and the workgroup HOME)
Click OK
Click OK in the computer properties windows.
(You may have to restart the computer. If you are prompted to, do so) 

Configuring Wireless Adaptor

Go to Start > Control Panel > Network Connections > Network Connections

Right-click on your wireless adaptor, click "Properties"

Click "Configurations"

The options available in the configurations will widely vary between wireless adaptors, but the main things that that you want to make sure are:

The type of connection is set to Adhoc and not Infrastructure

The security settings are off (It may be called "B/G Protection", nevertheless, set this to "none" or "off"

On some occasions, you may come across something that says "SSID" with a textbox corresponding to it. In this entry, you can specify a name for your network. Let's just call it "Home" for now

After altering the configuration settings, click "OK" to save the changes, and click "OK" again in the wireless adaptor window to exit

Right-click again on your wireless adaptor, click "Properties"

Click the tab "Wireless Network"

Click "Add" under "Preferred Network"

In the new window, type in the same SSID key that you may have specified in step 3. Otherwise, let's call it "Home" for now. Under "Network Authentication", select the option "Open" in the dropdown menu. Having done that, select "Disabled" under "Data encryption". Lastly, place a tick for the option "This is a computer-to-computer (ad hoc) network, wireless access points are not used". Click "OK" to save.

Click "OK" to exit the wireless adaptor window

Configuring IP

Go to Start > Control Panel > Network Connections > Network Connections

Right-click on your wireless adaptor and click "Properties"

Under the heading "This connection uses the following items", click "Internet Protocol (TCP/IP)

Click "Properties"

A new window should pop up, click "Alternate Configuration"

Click "User configured" radio button

Here, you can specify the address. For computer node1, specify the IP as 192.168.0.2, subnet mask as 255.255.255.0, default gateway as 192.168.0.1. Under Preferred / Alternate DNS server, the values for Xtra are 202.27.158.40 and 202.27.156.72 respectively (the address may vary between ISPs). If you are unable to determine your ISP's Preferred / Alternate DNS server addresses, just surf on to OpenDNS for options available.

Click "OK"

Click "OK" under the LAN connection properties.

You are done for computer node1

ON "node2"

Right-click "My Computer", click "Properties"

Click "Computer Name" Tab

Click "Change"

A window should pop-up. Specify a name for the computer.

Click "Workgroup" and specify a name. (We will call the node2 and the workgroup HOME)

Click OK

Click OK in the computer properties windows.

(You may have to restart the computer. If you are prompted to, do so) 

Configuring Wireless Adaptor

Go to Start > Control Panel > Network Connections > Network Connections

Right-click on your wireless adaptor, click "Properties"

Click "Configurations"

The options available in the configurations will widely vary between wireless adaptors, but the main things that that you want to make sure are:

The type of connection is set to Adhoc and not Infrastructure

The security settings are off (It may be called "B/G Protection", nevertheless, set this to "none" or "off"

On some occasions, you may come across something that says "SSID" with a textbox corresponding to it. In this entry, you can specify a name for your network. Let's just call it "Home" for now

After altering the configuration settings, click "OK" to save the changes, and click "OK" again in the wireless adaptor window to exit

Right-click again on your wireless adaptor, click "Properties"

Click the tab "Wireless Network"

Click "Add" under "Preferred Network"

In the new window, type in the same SSID key that you may have specified in step 3. Otherwise, let's call it "Home" for now. Under "Network Authentication", select the option "Open" in the dropdown menu. Having done that, select "Disabled" under "Data encryption". Lastly, place a tick for the option "This is a computer-to-computer (ad hoc) network, wireless access points are not used". Click "OK" to save.

Click "OK" to exit the wireless adaptor window

Configuring IP

Go to Start > Control Panel > Network Connections > Network Connections

Right-click on your wireless adaptor and click "Properties"

Under the heading "This connection uses the following items", click "Internet Protocol (TCP/IP)

Click "Properties"

A new window should pop up, click "Alternate Configuration"

Click "User configured" radio button

Here, you can specify the address. For computer node1, specify the IP as 192.168.0.1, subnet mask as 255.255.255.0, default gateway as 192.168.0.2. Under Preferred / Alternate DNS server, the values for Xtra are 202.27.158.40 and 202.27.156.72 respectively (the address may vary between ISPs). If you are unable to determine your ISP's Preferred / Alternate DNS server addresses, just surf on to OpenDNS for options available.

Click "OK"

Click "OK" under the LAN connection properties.

You are done for computer node2

Connecting the computers together

On either node1 or node2, right-click the wireless adaptor icon displayed in the system tray.

Click "View Available Wireless Network"

Double-click on the wireless computer-to-computer network "HOME" in the screen displayed

After both computers have acquired an IP address, you are done!