A Review of Current Routing Protocols for Ad

A Review of Current Routing Protocols for Ad Hoc Mobile Wireless Networks Author: E. Royer and C. -K. Toh Source: IEEE Personal Communication April 1999, vol. 6, no. 2, page. 48~51 Date: 2002/12/12

Outline n n n Introduction Table-Driven Routing Source-Initiated On-Demand Routing Comparisons Application and Challenges Conclusion

Introduction n Current variations of mobile wireless networks q Infrastructured network q Infrastructureless mobile network (Ad Hoc) n Existing Ad Hoc routing protocols q limitation of these networks n n n q High power consumption Low bandwidth High error rates Categorized as n n Table-driven Source-initiated (demand-driven)

Ad Hoc Routing Protocols Ad hoc routing protocols Source-initiated On-demand Table-driven DSDV CGSR WRP AODV DSR LMR ABR TORA SSR

Table-Driven Routing Protocols n n n Destination-Sequenced Distance-Vector Routing (DSDV) Clusterhead Gateway Switch Routing (CGSR) The Wireless Routing Protocol (WRP)

Destination-Sequenced Distance-Vector Routing n n n Based on Bellman-Ford algorithm Every mobile station maintains a routing table that lists all available destinations. The stations periodically transmit their routing tables to their immediate neighbors.

Movement in DSDV MH 4 forwarding table 1. update table 2. advertise changes 3 4 2 1 5 8 6 7 1

MH 4 forwarding table (updated) Destination Next Hop Metric Sequence Number Install Flag Stable_data MH 1 MH 6 3 S 561_MH 1 T 810_MH 4 M Ptrl_MH 1 MH 2 1 S 128_MH 2 T 001_MH 4 Ptrl_MH 2 MH 3 MH 2 2 S 564_MH 3 T 001_MH 4 Ptrl_MH 3 MH 4 0 S 710_MH 4 T 001_MH 4 Ptrl_MH 4 … MH 4 advertised table (updated) Destination Metric Sequence Number MH 4 0 S 820_MH 4 MH 1 3 S 516_MH 1 MH 2 1 S 238_MH 2 MH 3 2 S 674_MH 3 MH 5 2 S 502_MH 5 MH 6 1 S 186_MH 6 MH 7 2 S 238_MH 7 MH 8 3 S 160_MH 8

Clusterhead Gateway Switch Routing n Cluster member table q n The mobile nodes are aggregated into clusters and a cluster-head is elected. q n n Using DSDV algorithm. Least Cluster Change (LCC) algorithm A cluster-head control a group of ad hoc nodes. A gateway is a node that is in the communication range of two or more clusterheads.

CGSR Example 12 6 11 5 4 7 10 8 2 1 9 3 Internal node Gateway Cluster-head

The Wireless Routing Protocol n n A table-based distance-vector routing protocol Each node maintains q q Distance table Routing table Link-Cost table Message Retransmission List (MRL) table

Source-Initiated On-Demand Routing Protocols n n n Ad Hoc On-Demand Distance Vector Routing Dynamic Source Routing Temporally Ordered Routing Algorithm Associativity-Based Routing Signal Stability Routing

Ad Hoc On-Demand Distance Vector Routing n Route discovery q q n Route Request (RREQ) Route Reply (RREP) Route maintenance q q Hello messages Failure notification message

Ad Hoc On-Demand Distance Vector Routing (cont. ) Destination N 2 N 8 N 5 Source N 1 N 4 N 7 N 3 N 6

Ad Hoc On-Demand Distance Vector Routing (cont. ) Destination N 2 N 8 N 5 Source N 1 N 4 N 7 N 3 N 6

Dynamic Source Routing n Route discovery q q n Route request Route reply Route maintenance q Route error packets

Dynamic Source Routing N 1 -N 2 Destination N 2 N 1 -N 2 -N 5 Source N 8 N 5 N 1 N 1 -N 3 -N 4 N 1 -N 3 -N 4 -N 7 N 1 N 1 -N 3 -N 4 -N 6 N 3 N 1 -N 3 -N 4 N 6

Dynamic Source Routing N 2 N 1 -N 2 -N 5 -N 8 Source Destination N 1 -N 2 -N 5 -N 8 N 5 N 1 N 4 N 7 N 3 N 6 N 8

Temporally Ordered Routing Algorithm n Route creation q n Route maintenance q n Directed acyclic graph (DAG) New reference level Route erasure q Clear packet

Temporally Ordered Routing Algorithm (cont. ) Source Ad hoc node Height metric Destination

Temporally Ordered Routing Algorithm (cont. ) B A E G F (1) B C D E B A G F Link reversal C D E (4) G F (2) C D E (3) A D A B C G F Link failure

Associativity-Based Routing n Route discovery q q n Route reconstruction q q n Broadcast Query (BQ) Await-Reply (BQ-Reply) Route notification (RN) Localized query (LQ) Route deletion q Route delete (RD)

Associativity-Based Routing (cont. ) SRC BQ DEST SRC RN[1] Route maintenance for a source move

Associativity-Based Routing (cont. ) DEST LQ[H] SRC H=3 DEST RN[0] Route maintenance for a destination move

Signal Stability Routing n Route discovery q q n Route maintenance q n Beacon to each neighboring node Static Routing Protocol (SRP) Dynamic Routing Protocol (DRP) Route failed q Error message

Comparisons of Table-driven Protocols Parameters DSDV CGSR WRP Time complexity (link addition/failure) O(d) O(h)-routing tree Routing philosophy Flat Hierarchical Flat* Loop free Yes Yes Multicast capability No No**(separate) No Number of required tables Two Four Frequency of update transmissions Periodically and as needed Updates transmitted to Neighbors and cluster head Neighbors Utilizes hello messages Yes No Yes Critical nodes No Yes (cluster head) No

Comparisons of On-Demand Protocols Performance parameters AODV DSR TORA ABR SSR Time complexity (initialization) O(2 d) O(d+z) Time complexity (postfailure) O(2 d) or 0* O(2 d) O(l+z) Communication complexity (initialization) O(2 N) O(N+y) Communication complexity (postfailure) O(2 N) O(2 x) O(x+y) Routing philosophy Flat Flat Loop-free Yes Yes Yes Multicast capability Yes No No**(LAM) No No Beaconing requirements No No No Yes Multiple route possibilities No Yes No No Routes maintained in Route table Route cache Route table Route reconfiguration methodology Erase route; notify source Link reversal; route repair Localized broadcast query Erase route; notify source Routing metric Freshest and shortest path Associativity and shortest path and others*** Associativity and stability

Comparisons (cont. ) n ADOV VS. DSR q q Overhead of DSR is potentially larger than ADOV (carry information) Symmetric & Asymmetric Single route & Multiple routes DSR is not scalable to large networks

Comparisons (cont. ) n TORA (link reversal) q q Best suited for networks with large dense populations of nodes Multiple routes Fewer route rebuilding With LAM algorithm to provide multicast capability (GPS)

Comparisons (cont. ) n ABR q q q n Aggregated associativity ticks Guarantee to be free of packet duplicate Beacon SSR q q Signal strength and location stability not necessarily shortest in hop count Intermediate can’t reply (long delay)

Applications and Challenges n Application q q q n Military (non-fixed) Conference/meeting/lectures Emergency Challenges q q q Multicast (dynamic multicast-tree ) Qo. S support (MAC layer) Power-aware routing (handheld devices) Location aided routing (analogous ABR) security, service discovery, internet protocol operability.

Conclusion n n Classification Table-driven & On-demand Provide several routing scheme According Advantage & disadvantage to choose protocol and implement network Many challenge need to be met