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 Solution Mobile Ad 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 1LA 2 G2 G1 G1 is moving VLR

Signaling and Updates (2/2) New LALA 2 G2 G1 G1 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 3 LA 4

Geographical Area LA 1 LA 2 LA 3 LA 4

Geographical Area LA 1 LA 2 LA 3 LA 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 10 T1 T2 T3 LA 1 LA 2 LA 3 LA 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 IDGroup ID T1G1 T2G1 T3G1 T1 T2 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 10 T1 T2 LA 1 LA 2 LA 3 LA 4 FLN3 SLN 2’ FLN5 SLN 1 FLN6 SLN 3 FLN7 SLN 4 FLN10 SLN 4’ FLN11 Each SLN stores 2 Tables: T-G Table G-N Table For example in case of LA 1 we have: Group IDNode ID G6FLN5 TerminalGroup T4G6 T5G6 T6G6 T7G6

Geographical Area FLN2 FLN4 GL 2 GL 3 GL 1 GL 4 GL 5 GL 6 GL 7 GL 8 GL 9 GL 10 T1 T2 T3 LA 1 LA 2 LA 3 LA 4 FLN3 FLN5 SLN 1 FLN8 FLN6 SLN 3 FLN9 FLN7 SLN 4 FLN10 FLN11 FLN1 SLN2 TLN 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 N 1 G1G1 G2G2 Upon receiving the Group_Joining, the FLN in N 2 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 N 1. Accordingly this FLN deletes T in its T-G Table. SLN TLN FLN in N 2 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 N 1 G1G1 G2G2 SLN TLN FLN in N 2 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 N 2 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 G 1. Accordingly the SLN contacts the FLN of G 1 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)

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 New Responsible 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 Node Previous 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 i SLN TLN

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

Network Simulator ns-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