Group Management in Mobile Ad Hoc Networks Revathi Ranganathan

Preeti Venkateswaran

Mobile Ad hoc Networks

Wireless, self organising systems Co-operating nodes within communication

range form temporary networks Topology is dynamic de-centralised and ever

changing Nodes may move around arbitrarily

Scenarios

In the recent years several scenarios where users happen to move together have emerged. Examples:

Military Applications

Rescue Operations

Virtual Classrooms

SolutionMobileAd hoc

Networks

System Description

Terminals - Portable communication devices utilized by users.

- Identified by a unique ID.

- Rapid Mobility

- Limited Battery Capacity

- Short Transmission Range

System Description

Nodes - Communication devices usually hosted on trucks, tanks or laptops.

- provide a backbone for communications between terminals.

- Slow mobility. - High battery capacity. - Long transmission range.

Signaling and Updates

LA 1 LA 2

G2

G1G1 is moving

VLR

Signaling and Updates (2/2)

New LA LA 2

G2

G1G1 changed LA and numerous updates are necessary

VLR

Hierarchical Architecture

•We have implemented a three-level hierarchical location database architecture

•Reduces signaling overhead

Speeds up paging and locating terminals in spite of their potentially high mobility

Geographical Area

Mobile Ad hoc Networks for Group Operations

Geographical Area

LA 1

LA 2

LA 3LA 4

Geographical Area

LA 1

LA 2

LA 3LA 4

Geographical Area

LA 1

LA 2

LA 3LA 4

Geographical Area

FLN3

FLN2

FLN4

FLN1

FLN5

FLN6

FLN7

GL 2

GL 3

GL 1

GL 4

GL 5

GL 6 GL 7

GL 8 GL 9

GL 10T1T2

T3

LA 1

LA 2

LA 3LA 4

FLN8

FLN9

FLN10

FLN11

Geographical Area

FLN3

FLN2

FLN4

FLN1

FLN5

FLN6

FLN7

GL 2

GL 3

GL 1

GL 4

GL 5

GL 6 GL 7

GL 8 GL 9

GL 10

Each FLN contains a T-G Table.

For example, let us show the FLN1’s Table.

Terminal ID Group ID

T1 G1

T2 G1

T3 G1

T1T2

T3

FLN8

FLN10

FLN9

FLN11

Geographical Area

FLN2

FLN4

GL 2

GL 3

GL 4

GL 5

GL 6 GL 7

GL 8 GL 9

GL 10T1T2

LA 1

LA 2

LA 3

LA 4FLN3SLN 2’

FLN5SLN 1

FLN6SLN 3

FLN7SLN 4

FLN10SLN 4’FLN11

Each SLN stores 2 Tables:•T-G Table•G-N Table

For example in case of LA 1 we have:

Group ID Node ID

G6 FLN5

Terminal Group

T4 G6

T5 G6

T6 G6

T7 G6

Geographical Area

FLN2

FLN4

GL 2

GL 3

GL 1

GL 4

GL 5

GL 6 GL 7

GL 8 GL 9

GL 10T1T2

T3

LA 1

LA 2

LA 3

LA 4FLN3

FLN5SLN 1

FLN8

FLN6SLN 3

FLN9

FLN7SLN 4

FLN10

FLN11FLN1SLN2TLN

Each TLN serves a Geographical Area and contains a T-LA Table

Group Joining FLN1

Group Update Message

Diff FLN – Same LA

The Responsible Node of G1 and the new one are

different but belong to the same LA (same SLN)

FLN in N1

G1G2

Upon receiving the Group_Joining,

the FLN in N2

registers T in its T-G Table. Then it sends SL_Group_Update

to the SLN which updates its T-G Table

accordingly.The SLN sends then a FL_User_Delete to

the FLN in N1.Accordingly this FLN

deletes T in its T-G Table.

SLN

TLN

FLN in N2

SL_Group_Update

FL_User_Delete

Group_Joining

Diff FLN – Diff LA The Responsible Node of G1 and G2 are in different

LAs but in the same Geographical Area.(same TLN)

FLN in N1

G1G2

SLNTLN

FLN in N2

SL_Group_Update

Group_Joining

SLN

TL_Group_Update SL_User_Delete

FL_User_Delete

Initially the operations are the

same as in the previous case.

Then, upon receiving the

SL_Group_Update, the SLN in N2

registers T in its T-G Table. Then it sends TL_Group_Update

to the TLN which updates its T-LA

Table accordingly.The TLN sends then a SL_User_Delete to

theSLN of G1.Accordingly the SLN contacts the FLN of

G1 to let it delete T as in the previous case.

Group Location Updating(Required when a group changes its Responsible Node)

Case 1: Change RN and not LA

Node j

Beacon(Node_ID, LA_ID)

Node i

The Head Nodes continuosly transmit a beacon signal. Each GL receives these beacons and calculates its distance from those.Then it selects as the new Responsible Node the one which is closest to it.

GL

Previous Responsible

Node

Beacon(Node_ID, LA_ID)

Beacon(Node_ID, LA_ID)

Group Location Updating(Required when a group changes its Responsible Node)

Node j

Node i

If GL recognizes that Node i is closest to it transmits to Node i a Change_RN message. Node i sends to the SLN an Update_RN_SLN message to the SLN. The SLN modifies its tables and sends to Node i a Add_Group_Users. In addition the SLN sends to the previous RN a Delete_Group_Users and then updates its own G-N Table.

GL

Previous Responsible

Node

Change_RN

SLN

Case 1: Change RN and not LA

Group Location Updating(Required when a group changes its Responsible Node)

Node j

Node i

GL

Previous Responsible

Node SLN

Update_RN_SLN

If GL recognizes that Node i is closest to it transmits to Node i a Change_RN message. Node i sends to the SLN an Update_RN_SLN message to the SLN. The SLN modifies its tables and sends to Node i a Add_Group_Users. In addition the SLN sends to the previous RN a Delete_Group_Users and then updates its own G-N Table.

Case 1: Change RN and not LA

Group Location Updating(Required when a group changes its Responsible Node)

Node j

Node i

GL

Previous Responsible

Node SLN

Add_Group_Users

Delete_Group_Users

If GL recognizes that Node i is closest to it transmits to Node i a Change_RN message. Node i sends to the SLN an Update_RN_SLN message to the SLN. The SLN modifies its tables and sends to Node i a Add_Group_Users. In addition, the SLN sends to the previous RN a Delete_Group_Users and then updates its own G-N Table.

Case 1: Change RN and not LA

Group Location Updating(Required when a group changes its Responsible Node)

Node j

NewResponsible

Node

GL

Previous Responsible

Node SLN

Case 1: Change RN and not LA

Group Location Updating(Required when a group changes its Responsible Node)

Node j

Node i

GL

Previous Responsible

NodePrevious

SLN

Case 2: Change RN and LA, but not GA

In addition to what was said before, the 2 SLNs must be also involved. Furthermore also the

T-LA Table in the TLN must be updated.

Node’s iSLN

TLN

Reference:

Spontaneous Group Management in Mobile Ad-Hoc Networks

- LAURA GALLUCCIO, GIACOMO MORABITO and SERGIO PALAZZO

Network Simulatorns-2.27

What is ns?

A discrete event packet-level simulator Targeted at networking research Wired and Wireless

Architecture: Object Oriented C++

- to implement protocols

OTcl

- to write simulation scripts

Simulation Components

Node

- Nodes are “hardware entities” in a network

Agent

- Agents are “software entities” which are on these nodes (eg: Tcp, Udp, DSDV, AODV etc)

Simultion Components(contd…..) Link

- Links connect nodes in wired networks.

- Links can be simplex and duplex Wireless networks do not have links between

the nodes (obviously!!)

- Nodes are connected to wireless channel

Simultion Components(contd…..) Traffic Generator Source

- An agent which is the originator of packets Sink

- An agent which is the destination of these packets

Simulating in ns-2.27

Create the event scheduler [ Turn on tracing ] Create network Setup routing Insert errors Create transport connection Create traffic Transmit application-level data

Implementing mobile node by Extending “standard” NS node

Node

ARP

Radio Propagation Model

MobileNode

LL

MAC

PHY

LL

CHANNEL

Routing