some typical routing protocols in mobile ad hoc networks

Some Typical Routing Protocols in

Mobile Ad Hoc NetworksAdvanced Networking Course

Mehdi SadriJamshid Esmaeilnejad

Spring 2012

Classification

Zone Based Hierarchical Routing Protocols

1. The Zone Routing Protocol (ZRP)2. The Hybrid Ad hoc Routing Protocol (HARP)3. The Zone-based Hierarchical Link State Routing

(ZHLS)

Zone Based Hierarchical Routing Protocols

The Zone Routing Protocol (ZRP)

• The First hybrid routing protocol.• HRP motivations:

o Reduce control overhead of proactive routing protocols

o Decrease latency caused by route search operations in reactive approaches


Partitioning into zones....• Network is divided into routing zones.• Given node N:

nodes within hop distance at most d => N's routing zone.

• Peripheral nodes: nodes which are exactly d hops away from N.


Routing ...

• Different routing approaches are exploited.• Inter-zone : Inter-zone Routing Protocol (IERP)• Intra-zone : Intra-zone Routing Protocol (IARP)


Routing Example ...

The Hybrid Ad hoc Routing Protocol (HARP)

• Similar to ZRP : different routing approaches use in different levels of zone hierarchy (Intra and Inter zone routing).

• Similar to ZRP :o Intra-zone routing : existing proactive schemeo Inter-zone routing : existing reactive scheme


Distributed Dynamic Routing (DDR)

1. Nodes periodically exchange topology messages.2. A forest is constructed from the network topology in

a distributed way.3. Each tree in the forest becomes a zone.


Gateway nodes ...

Nodes which are in different zones but are within the direct transmission range are defined as gateway nodes.


Distributed Dynamic Routing (DDR)

The Zone-based Hierarchical Link State routing (ZHLS)

• Another hybrid routing protocol• Nodes are assumed to know their physical location

with assistance from a location system like GPS• Network is partitioned into non-overlapping zones

based on geographical information.


• Hierarchical addressing structure which contains node ID and zone ID

• Two-level network topology a. node level : node level LSP (broadcasted in each

zone)b. zone level : zone level LSP (broadcasted by zone

gateways when a virtual link is broken or created)


Routing ...

1. A wants to send a packet to B.2. if B is in the same zone, A knows B3. if not, the gateways of A's zone ask neighbors.4. Each node which receives a location request checks

its intra-zone routing table and returns the address or forwards to other neighbors.


Routing (Example)

Cluster-based routing protocols

• The Clusterhead Gateway Switch Routing (CGSR)

• The Hierarchical State Routing

• Cluster Based Routing Protocol (CBRP)

• Comparison of cluster based hierarchical routing protocols presented

Clusterhead Gateway Switch Routing (CGSR)

• CGSR is a hierarchical routing protocol.• Cluster Structure

o Provides Effective Membership and Traffic Management. Performance Improvement

• Similar Proactive routing mechanism as DSDV (Destination-Sequenced Distance-Vector Routing (DSDV) is a table-driven routing scheme for ad hoc mobile networks based on the Bellman-Ford algorithm.)

Routing Information Collection, Update and Distribution

+Cluster Construction and Cluster Head Selection

CGSR (cont.)

• Mobile nodes are aggregated into clusters.

• A clusterhead is elected for each cluster.

• Gateway nodes are responsible for communication between two or more clusterhead.

• Nodes maintain a cluster member table that maps each node to its respective clusterhead.

CGSR (cont.)

• A node broadcasts its cluster member table periodically.

• After receiving broadcasts from other nodes, a node updates its cluster member table.

• Each node maintains a routing table that determines the next hop to reach other clusters.

• Dynamic Networko Performance Degradation

Frequent elections of a Clusterhead.

• Least Cluster Change (LCC) algorithmo Two clusterheads merging into one.o A node being out of the coverage of all current

clusters.

CGSR (cont.)

• Forwarding a Packeto Node first checks both its cluster member table and

routing table.o Tries to find the nearest clusterhead along the

routing path.

The Hierarchical State Routing (HSR)• A multi-level cluster-

based hierarchical routing protocol.

• The clusterheads of low level clusters again organize themselves into upper level clusters, and so on.

HSR (cont.)

• Inside a cluster, nodes broadcast their link state information to all others.

• The clusterhead summarizes link state information of its cluster and sends the information to its neighboring clusterheads.

• Nodes in upper level hierarchical clusters flood the network topology information they have obtained to the nodes in the lower level clusters.

• A hierarchical address is assigned to every node. Hierarchical address reflects the network topology and provides enough information for packet deliveries in the network.

HSR (cont.)

• Nodes are also partitioned into logical subnetworks corresponding to different user groups.

• Each node has a logical address in the form of <subnet, host>.

• For each subnetwork, there is a location management server (LMS) which records the logical addresses of all nodes in the subnetwork.

• LMSs advertise their hierarchical addresses to the top level of hierarchical clusters.

• The routing information,which contains LMSs’ hierarchical addresses, is sent down to all LMSs.

HSR (cont.)

• Source node only knows the logical address of the destination node.o The source node first checks its LMS and tries to

find the hierarchical address of the destination’s LMS.

o The source sends the packet to the destination’s LMS.

o The destination’s LMS forwards the packet to the destination.

• Once the source knows the hierarchical address of the destination, it sends packets directly to the destination without consulting LMSs.

HSR (cont.)

In HSR, logical addresses reflect the group property of mobile nodes and hierarchical

addresses reflect their physical locations.

Combining these addressing schemes can improve adaptability of the routing algorithm.

Cluster Based Routing Protocol (CBRP)The clustering algorithm is performed when a node joins

the network.

• Node is "undecided" When joinso Sets a timer and broadcasts a Hello message.o A clusterhead receives the Hello message.o Replies with a triggered Hello message.o The “undecided” node changes its state to "member"

state.

o If the “undecided” node does not receive a message from a clusterhead before the local timer generates a timeout, it makes itself a clusterhead.

CBRP (cont.)

• In CBRP, every node maintains a neighbor table in which it stores the information about link states (uni-directional or bi-directional) and the state of its neighbors.

• A clusterhead keeps information of its neighboring clusters, which includes the clusterheads of neighboring clusters and gateway nodes connecting it to neighboring clusters.

Comparison of cluster based hierarchical routing protocols presented

Different clustering algorithmsDifferent clusterhead election algorithms

HSR:• Hierarchical addressing is used and the network may have a recursive

multi-level cluster structure.

• A location management mechanism is used to map the logical address to the physical address.

CGSR:• Every node keeps routing information for other nodes in both the cluster

member table and the routing table.CBRP:• A clusterhead maintains information about its members and its

neighboring clusterheads.

• Exploits the source routing scheme and the addresses of clusterheads along a route are recorded in the data packets.

Core-node based routing protocols

Landmark Ad hoc Routing (LANMAR)

• A modification Fisheye State Routing (FSR)• Aims to get better scalability• Belongs to non-uniform category


• Nodes are divided into logical predefined subsets : w.r.t. moving patterns

• Nodes in one subset are prone to move as a group

• One node becomes Landmark of the subset and is responsible to keep track of the subset


Routing ...

• Each node maintains :o topology information of its neighborso all the landmark nodes

• Similar to FSR, periodically nodes exchange:o Topology information to neighborso the distance vector of landmark nodes


Routing ...• Source wants to send message to destination

• if it is in the same subnet its address exists in source routing table

• if not, o dest. subnet is identified from dest. addresso message is forwarded toward dest. landmark uysing

the distance vector.


Snapshot ...

The Core-Extraction Distributed Ad Hoc Routing (CEDAR)

• Another non-uniform routing protocol• A subset of nodes are identified as core

nodes• A distributed algorithm to select core nodes• The number of core nodes is kept small


• Choosing core nodes : guarantees o each node must be adjacent to at least one core

node => this core becomes its dominatoro each core node is at least 3 hops away from another

core node

• Neighboring nodes periodically exchange link state information to choose the cores

• Every core node determines paths to core node nearby using localized broadcasts


Link state information propagation ...• It is done only between core nodes• Propagation distance is a function of link

stability and bandwidth• Result : Core nodes know

a. local link state informationb. the state of stable and high bandwidth nodes far

away


Routing ...• S wants to send packet to D• S informs its dominator (SD)• SD finds a route in core network to D's

dominator (DD) - DSR like discovery process• Core nodes involved in the path build a route

from S to D

The Optimized Link State Routing protocol (OLSR)

• Proactive & Table-driven

• Link State Routingo Each node expands a spanning treeo Each node can obtain the whole network topology

• Utilizes a technique to reduce message floodingo MultiPoint Relaying (MPR)

OLSR (cont.)• Each node periodically floods status of its links.• Each node re-broadcasts link state information received from its neighbors.• Each node keeps track of link state information received from other nodes.• Each node uses above information to determine next hop to each

destination.

• Only selected neighbors (MultiPoint Relays, MPRs) retransmit messages• Select MPRs such that they cover all 2-hop neighbors• 2-hop neighbors taken from neighbors' HELLO messages

Comparison of CEDAR, OLSR and LANMAR

• In a core-node based routing protocol, the core-node extraction method is a key component.

• CEDAR,OLSR and LANMAR apply totally different approaches for core node extraction purpose.

• In LANMAR, the landmark nodes are application related and pre-defined according to their mobility pattern.

• In CEDAR, a minimal (or nearly minimal) set of core nodes is selected to cover the network according to a certain optimization algorithm.

• A node selects its MPR independently in OLSR.

References[1] Z. J. Haas. The Zone Routing Protocol (ZRP) for ad hoc networks, Internet

Draft, Nov. 1997.[2] M. Joa-Ng and I-Tai Lu, A peer-to-peer zone-based two-level link state

routing for mobile ad hoc networks,IEEE on Selected Areas inCommunications, vol. 17, no. 8, pp. 1415 1425, 1999.[3] Navid Nikaein, Christian Bonnet and Neda Nikaein, HARP - Hybrid Ad Hoc

Routing Protocol, in proceeding of IST 2001: International Symposium on Telecommunications, Iran/Tehran 2001.

[4] Mingliang Jiang, Jinyang Li and Y. C. Tay. Cluster Based Routing Protocol (CBRP), Internet draft,draft-ietf-manet-cbrp-spec-01.txt.

[5] C. C. Chiang, T. C. Tsai, W. Liu and M. Gerla, Routing in clustered multihop, mobile wireless networks with fading channel, The Next Millennium, The IEEE SICON, 1997.

[6] P. Jacquet, P. Muhlethaler, and A. Qayyum, Optimized Link State Routing Protocol, IETF MANET, Internet draft, 1998.

References[7] Z. J. Haas and M.R Pearlman, The Zone Routing Protocol (ZRP) for ad hoc

networks. IETF Internet draft , August 1998.[8] P. Sinha, R. Sivakumar and V. Bharghaven, CEDAR: a Core-Extraction

Distributed Ad hoc Routing algorithm. IEEE INFOCOM, March 1999. [9] A. Iwata, C.-C. Chiang, G. Pei, M. Gerla, and T.-W. Chen, Scalable routing

strategies for ad hoc wireless networks. IEEE Journal on Selected Areas in Communications, Special Issue on Ad-Hoc Networks, August 1999, p1369-p1379.

[10] G. Pei, M. Gerla, and X. Hong, LANMAR: Landmark routing for large scale wireless ad hoc networks with group mobility. In Proceedings of the ACM Symposium on Mobile Ad Hoc Networking and Computing (MOBIHOC), pages 11-18, 2000.

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