Group Management in Mobile Ad Hoc Networks

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Group Management in Mobile Ad Hoc Networks

• Revathi Ranganathan
• Preeti Venkateswaran

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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

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

• Military Applications
• Rescue Operations
• Virtual Classrooms

Mobile Ad hoc Networks
Solution
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System Description

• Terminals - Portable communication devices
  utilized by users.
• - Identified by a unique ID.
• - Rapid Mobility
• - Limited Battery Capacity
• - Short Transmission Range

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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.

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Signaling and Updates
VLR
G2
LA 1
LA 2
G1
G1 is moving
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Signaling and Updates (2/2)
VLR
G2
G1 changed LA and numerous updates are
necessary
G1
New LA
LA 2
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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

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Mobile Ad hoc Networks for Group Operations
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LA 1
LA 2
LA 4
LA 3
Geographical Area
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LA 1
LA 2
LA 4
LA 3
Geographical Area
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LA 1
LA 2
LA 4
LA 3
Geographical Area
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GL 6
FLN8
GL 7
GL 5
LA 1
FLN5
LA 2
FLN3
FLN6
GL 9
GL 8
GL 3
FLN2
FLN7
FLN11
T3
LA 4
FLN1
GL 1
LA 3
GL 2
T2
T1
FLN9
GL 10
GL 4
FLN4
FLN10
Geographical Area
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Each FLN contains a T-G Table. For example, let
us show the FLN1s Table.
GL 6
FLN8
GL 7
GL 5
FLN9
FLN5
FLN3
FLN6
GL 9
GL 8
GL 3
FLN2
FLN7
FLN11
T3
FLN1
GL 1
GL 2
T2
T1
FLN10
GL 10
GL 4
FLN4
Geographical Area
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GL 6

• Each SLN stores 2 Tables
• T-G Table
• G-N Table
• For example in case of LA 1 we have

GL 7
GL 5
LA 1
LA 2
LA 4
GL 9
GL 3
GL 8
FLN2
FLN11
LA 3
GL 2
T2
T1
GL 10
GL 4
FLN4
Geographical Area
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GL 6
Each TLN serves a Geographical Area and contains
a T-LA Table
GL 7
FLN8
GL 5
LA 1
LA 2
FLN3
LA 4
GL 9
GL 3
GL 8
FLN2
FLN11
T3
GL 1
LA 3
FLN10
GL 2
T2
T1
GL 10
FLN9
GL 4
FLN4
Geographical Area
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Group Joining
FLN1
Group Update Message
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Diff FLN Same LAThe Responsible Node of G1
and the new one are different but belong to the
same LA (same SLN)
TLN
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.
FL_User_Delete
SLN
FLN in N1
FLN in N2
SL_Group_Update
Group_Joining
G2
G1
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Diff FLN Diff LA The Responsible Node of G1
and G2 are in different LAs but in the same
Geographical Area.(same TLN)
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.
SL_User_Delete
TLN
TL_Group_Update
SLN
SLN
SL_Group_Update
FL_User_Delete
FLN in N1
FLN in N2
Group_Joining
G2
G1
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Group Location Updating(Required when a group
changes its Responsible Node)
Case 1 Change RN and not LA
GL
Node j
Beacon(Node_ID, LA_ID)
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.
Beacon(Node_ID, LA_ID)
Beacon(Node_ID, LA_ID)
Node i
Previous Responsible Node
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Group Location Updating(Required when a group
changes its Responsible Node)
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
Node j
GL
Change_RN
Node i
Previous Responsible Node
SLN
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Group Location Updating(Required when a group
changes its Responsible Node)
Case 1 Change RN and not LA
Node j
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
Node i
Previous Responsible Node
Update_RN_SLN
SLN
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Group Location Updating(Required when a group
changes its Responsible Node)
Case 1 Change RN and not LA
Node j
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
Node i
Add_Group_Users
Previous Responsible Node
SLN
Delete_Group_Users
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Group Location Updating(Required when a group
changes its Responsible Node)
Case 1 Change RN and not LA
Node j
GL
New Responsible Node
Previous Responsible Node
SLN
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Group Location Updating(Required when a group
changes its Responsible Node)
Case 2 Change RN and LA, but not GA
GL
Node j
TLN
Node i
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.
Nodes i SLN
Previous Responsible Node
Previous SLN
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Reference

• Spontaneous Group Management in Mobile Ad-Hoc
  Networks
• - LAURA GALLUCCIO, GIACOMO MORABITO and
  SERGIO PALAZZO

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Network Simulatorns-2.27
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What is ns?

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

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Architecture Object Oriented

• C
• - to implement protocols
• OTcl
• - to write simulation scripts

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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)

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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

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Simultion Components(contd..)

• Traffic Generator
• Source
• - An agent which is the originator of packets
• Sink
• - An agent which is the destination of these
  packets

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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

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Implementing mobile node by Extending standard
NS node
Node
Routing
MobileNode
CHANNEL