Mobile Ad Hoc Network of Simulation Framework Based on OPNETAteeq AteeqPresentation

What is Adhoc• Wireless connection.• Short-term, temp connection between computers and devices.• Locates in two or more wireless net adapters• No access points• Used for a specific purpose, such as sharing documents during a

meeting or playing multiplayer computer games.

What is Adhoc

Mobile Adhoc Network• Knows as MANET.• Distributed system. • Composed of wireless nodes which can freely move and build

up any network topology.• Continuously self-configuring.• Infrastructure-less.

Characteristics of Ad Hoc• Nodes are equal.• No central control node.• Self organized.• Dynamic topology.• Multi-hop routing.• Nodes have 2 main functions categories:• Ordinary mobile terminals functions.• Packet Forwarding.

Characteristics of Ad Hoc – Self organizing• Self-organizing Network known as SON• It’s an “Automation technology” designed to make the

planning, configuration, management, optimization and healing of mobile radio access networks simpler and faster.

• Plug and Play - new nodes shall automatically be configured and integrated into the network.

Characteristics of Ad Hoc – Multi-hop routing• Routing is the process of deciding where to send signals in a

network. • Multi-hop routing involves sending signals through multiple

stops instead of one long pathway.

Characteristics of Ad Hoc – Packet forwarding• Packet forwarding is the relaying of packets from one network

node to another by nodes in the network.

Adhoc applications• Where to use Adhoc?• used in some spots where network equipment can not or can not

conveniently be built up, and in some other places where automatic network

• Ad hoc in military• Ad hoc units are created during unpredictable situations, when

the cooperation between different units is suddenly needed for fast action.

• Emergency and temp usage.• Personal usage.

Adhoc applications - Military

Adhoc applications - Personal

Adhoc applications - Emergency

Adhoc applications – Cellular network• Enlarge cellular mobile communicating system's coverage.• Balance operations in two neighbor districts.• Improve the statistics' efficiency at the edge of one district.

Adhoc usage – General view

Adhoc Routing Methods• Two routing methods:• Table-driven routing• Source demand routing

Table driven routing• Named: active routing.• Each note needs to maintain one or more routing table to save

accordant routing information all net.• Nodes are grouped through periodic broadcast routing

information • Nodes change router information, find available routers, and

select the shortest route in the preposition of link cost metric.

Source demand routing• A node does not need to maintain any route that is going to

other nodes.• The only necessity is that source node start the routing and

find out the process in order to set up a routing. • Once a routing is established, some kind of routing

maintenance does the maintenance job, until every node sent from source node in every route is not available, or is not in need any more.

Source demand routing

Adhoc routing protocols• The major problem for establishing an Ad Hoc network is to

explore a perfect routing protocol.• Ad hoc routing protocols• DSDV (Destination Sequenced Distance Vector)• TORA (Temporally-Ordered Routing Algorithm)• DSR (Dynamic Source Routing)• AODV (Ad Hoc On-Demand Distance Vector)• MAC (Media Access Control)

Destination Sequenced Distance Vector

• Table Driven• Each entry in the routing table contains a sequence number• The sequence numbers are generally even if a link is in use

else, an odd number is used. • The number is generated by the destination, and the sender

needs to send out the next update with this number. • Routing information is distributed between nodes by sending

full dumps infrequently and smaller incremental updates more frequently.

Destination Sequenced Distance Vector

Destination Next Hop Number of Hops

Sequence Number Install Time

A A 0 A 46 001000

B B 1 B 36 001200

C B 2 C 28 001500

Naturally the table contains description of all possible paths reachable by node A, along with the next hop, number of hops and sequence number.

Ad Hoc On-Demand Distance Vector

• Routing Protocol for MANET and other WLAN.• AODV is offering:• Quick adaptation to dynamic link conditions• Low processing and memory overhead• Low network utilization• Determines unicast routes to destinations within the ad hoc

network. • It uses destination sequence numbers to:• Ensure loop freedom at all times• Avoiding problems "counting to infinity"

Ad Hoc On-Demand Distance Vector

DSDV VS AODV• Both are table driven• DSDV send the update frequently• AODV send the update on demand• AODV make less load on the network• AODV make less congestion on the network

DSDV VS AODVDSDV AODV

Routes maintained through periodic and event triggered routing table exchanges

Reactive / On-demand

higher overhead Low in average – on demand

few nodes and many data sessions Sessions are on demand

Not efficient for large ad-hoc networks Scalable

Nodes need to maintain a complete list of routes

Maintains only active routes

MANET Modeling in OPNET• First Level - Net level:• Focus on the description of network topology.

• Second level: • Description of all kinds of node model consist of this network

topology.• Node model is like a multi-process stack.

• Third level:• Description of each process that composes the node model.

MANET Models• Two models:• Network model• Node model

• Network model• A network is composed of many mobile nodes• 0, I, 2 ... N-I nodes• Communicate through wireless link. • Network topology changes with moving the nodes.

MANET Models• Node model• Every node in the network is marked by a unique IP address.• All the nodes have the same node model to emphasize routing

realization. • Node model consists of the following factors:

• Source module• Application module• Routing module• Wireless- mac module,• Wlan-rx + wlan-tx module ( radio transmitters and receivers)• Sink module and mobility module.

Realization• Network is composed of 16 wireless mobile nodes• Area size: 1000m X 500m area. • All the nodes are equal• Nodes are distributed freely in this area. • Node model is including : • routing module• wireless-mac module• wlan-rx and wlan-tx module• process model, selected by mobility module

Realization• Realization can be found in the following parts:• Routing process model• Physical layer and link layer model• Mobile link model• Performance measurement and simulation results

Realization - Routing process model• Take the AODV (Ad-hoc On-demand Distance Vector) to

describe modeling and simulation of routing algorithm. • Routing algorithm does the exploration.

Realization - Routing process model

Realization - Physical layer and link layer model• Every node has one or more wireless network interface.• Interfaces are connected by physical channel.• When network interface send packets:• The interface transmits packet to a suitable physical channel

object.• The physical channel object calculates the delay from the sender

to other nodes, and arranges a packet for each node to receive events.

• The event informs the network interface, and then the first beta of a new packet reaches.

Realization - Physical layer and link layer model• for physical layer and MAC layer that we need, we take

frequency-hopping mode, BPSK modulation signal, fading channels as an example.• Frequency Hopping Spread Spectrum (FHSS) is a method of

transmitting radio signals by rapidly switching a carrier among many frequency channels

• Phase-shift keying (PSK) is a digital modulation scheme that conveys data by changing (modulating) the phase of a reference signal (the carrier wave).

• BPSK is stands for Binary Phase Shift Keying

Realization - Physical layer and link layer model

Realization – Mobile node model• A node can firstly find out a target node in the network.• The node moves to the target at a fixed pace which is fixed

stochastically. • When this node reaches the target node, it will pause for

waiting time, and calculate the next target.• location of node i: Fi = I xi - yi I• Relative distance of all nodes :• When node move: • Total distances: • Mobility factor:

Realization – Mobile node model

Realization – Mobile node model• Random waypoint model is a random model for the

movement of mobile users, and how their location and acceleration change over time.

• It’s the most popular mobility models to evaluate mobile ad hoc network (MANET) routing protocols, because of its simplicity and wide availability.

Realization – Mobile node model

Realization – Mobile node model

Performance measurement and simulation results• Statistics calculated includes:• Delay • Throughout• Efficiency• Overhead

Realization - Performance measurement and simulation results• Delay and mobility• When network topology changes, the routing changes or finds a

new one, so definitely the transmitting time will be longer.

Realization - Performance measurement and simulation results• Throughout and mobility• Because the node moves frequently brings changes in network

topology, so the network need more time to find the routing, and fight for channel.

• Efficiency and mobility• Because a node's frequent movement will cause interruption and

packet loss.

Realization - Performance measurement and simulation results

• Efficiency, overhead and norm• There we take four schemes to compare: None, MAC, Hello, and

Hello + MAC. Obviously, application of management of local connectivity

Realization - Performance measurement and simulation results

The End