Multicasting routing protocols in ad hoc

We construct paper in six part, first introduction, second multicast overview, third protocols, forth multicasting and different routing, fifth conclusion, and finally references.. Ad ho

Multicasting Routing Protocols in Ad hoc Networks Ahmad Ghasemi1, Mostafa Abdollahi2, Ali Amirhamidi3 and Asadollah Salimi Dehkodi4

1,2,3,4

Department of Electrical Engineering, Boroujen Branch, Islamic Azad University, Boroujen, Iran

ahmadqassemi@gmail.com , Mostafa.Abdollahi.Bastaki@gmail.com , ali_amirhamidi@yahoo.com ,

asad_salimy@yahoo.com

Abstract

In mobile ad hoc networks (MANETs) for good performance must be considered as energy

consumption, protocols in different layers, etc In this paper we try to investigate and compare

different methods for multicasting routing protocols in ad hoc networks to provide guidelines for the

engineers that work with ad hoc and sensor networks

Keywords: mobile ad hoc networks, multicasting, routing, Tree approach, Mesh approach

1 Introduction

A mobile ad hoc network (MANET) represents a system of wireless mobile nodes that can

freely and dynamically self-organize into arbitrary and temporary network topologies without

the presence of any fixed communication infrastructure Reliable routing and robustness of the

network are two important issues for MANETs In this paper we try to investigate and compare

different methods for multicasting routing protocols in ad hoc networks to provide guidelines

for engineers that work with ad hoc and sensor networks

We construct paper in six part, first introduction, second multicast overview, third protocols,

forth multicasting and different routing, fifth conclusion, and finally references

2 Multicast overview

Multicast is the delivery of information to a group of destinations , in figure 1 show

broadcast, multicast and unicast, pictorially

(a) (b) (c)

Figure 1 a) broadcast, b) multicast, and c) unicast

A multicast application can be characterized as one of three types: I) on e to many, II) many

to many, III) many to one, that show in figure 2, pictorially

(a) (b) (c)

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3 Protocols

Protocols are classified into three categories based on how route the members of group is

created, i.e

I) Tree approaches

a) Source-based

b) Core-based

II) Mesh approaches

III) Hybrid approaches

Now we overview this categories

Source-based tree approach: in this approach between each source and eac h receiver to reach

all addresses of nodes construct a tree, e.g see figure 3

Figure 3 Construct a tree between source and receiver in source-based tree approach

This approach have some advantages and disadvantages, that it’s advantages are I) const ruct

optimal path from source to receiver that minimizes delay, II) good for small number of sender,

and it’s disadvantages are I) inefficient in high mobility networks, II) inefficient in large

networks

Core-based tree approach: in this approach between all source and all receiver to reach all

addresses of nodes construct only a tree, e.g see figure 4

Figure 4 Construct only a tree for all sources in core-based tree approach

This approach have some advantages and disadvantages, that it’s advantage are I) good for

many sender with low bandwidth, and it’s disadvantages are I) construct sub -optimal path from

source to receiver, II) extra delay

In total for tree approaches we see that I) a packet traverses each hop and node in a tree at

most once, II) very simple routing decisions at each node and III) tree structure built

representing shortest paths amongst nodes, and a loop -free data distribution structure

Mesh-based approach: in this approach may have multiple routes to reach a destination while

the tree-based protocols maintain only one path [1], then outperform tree -based proposals due to

availability of alternative paths And in this approach due to redundant forwarding consumes

more bandwidth and the probability of collisions is higher when a larger number of packets are

generated

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Hybrid approach: hybridbased ad hoc multicast routing protocols combine of both tree

-based and mesh based approaches and overcome their shortcomings Examples of a hybrid

protocol is TORA [2], Zone Routing Protocol (ZRP) [3]

There are other categories based on structure (or structure -based) which have been used in

some literatures that is:

a) Tree-based

b) Mesh-based

4 Multicasting and different routing

Some important problems must be considered in multicasting in MANETs, as nodes may join

or leave the multicast group anytime, and in traditional networks, often the physical topology

does not change, whereas in MANETs the physical topology can change

Several new protocols have been proposed for multicasting in MANETs that are classified

into two categories:

I) Table-driven or proactive

a) AMRoute b) CAMP/WRP II) On-demand or reactive

a) AMRIS b) ODMRP Now we overview this categories

Ad hoc Multicast Routing (AMRoute): this routing use tree approach for multicast data

forwarding, and use unicast tunnels to provide connections between multicast group members

In this each group has at least one logical core [4]

Mesh creation in AMRoute: first each group member declares itself as a core for it’s own

group of size one, then each core periodically floods JOIN-REQs to discover other disjoint

mesh segments, see figure 5

Figure 5 Each core periodically floods JOIN-REQs to discover other disjoint mesh segments

When a member node receives a JOIN-REQ from a core, it replies with a JOIN-ACK and

marks that node as a mesh neighbor, then the node that receives a JOIN-ACK also marks the

sender of the packet as it’s mesh neighbor, see figure 6

Figure 6 A member node receives a JOIN-REQ from a core, it replies with a JOIN-ACK

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After the mesh creation, each core periodically transmits TREE-CREATE packets to mesh

neighbors in order to build a shared tree, when a member node receives non-duplicate

TREE-CREATE from one of its mesh links, it forwards the packet to all other mesh links If duplicate

TREE-CREATE are received, a TREE-CREATE-NAK is sent back along the incoming link

The node receiving a TREE-CREATE-NAK marks the link as mesh link instead of tree link

The nodes wishing to leave the group send the JOIN-NAK to the neighbors and do not

forward any data packets for the group

Characteristics of AMRoute:

a) Usage of virtual mesh links to establish the multicast tree

b) Nonmembers do not forward data packets

The major disadvantage of AMRoute: it suffers from temporary loops and creates non

-optimal trees when mobility is present [4]

Ad hoc Multicast Routing Protocol utilizing Increasing ID -number (AMRIS): this routing use

tree approach for multicast data forwarding, and it is on-demand protocol In this dynamically

assign an ID-number to each node in each multicast session [5]

Some phrases that use in this routing, Sid: is Smallest -ID and is usually a source that initiates

a multicast session, that is selected among set of senders, and msm-id: is multicast session

member ID

Initiates a multicast session in AMRIS: Sid initiates a multicast session by broadcasting a

NEW-SESSION massage, then all receivers generate their own msm-id based on the value

found in NEW-SESSION message, then rebroadcast NEW-SESSION with its msm-id, see figure

7

Figure 7 Initiates a multicast session in AMRIS

Join the tree in AMRIS: if the requesting node X has a neighbor who is already on the tree,

JOIN-REQ is unicasted to that neighbor Y, then neighbor Y will send back JOIN -ACK to

confirm new X is its child If the neighbors are not on the tree, but have smaller msm-id

I) X send JOIN-REQ to one of the neighbor Y

II) After receiving a JOIN-REQ, neighbor Y sends out its own JOIN-REQ

III) If the parent node Y can successfully join the tree, then it sends a JOIN -ACK to X,

otherwise it will sends a JOIN-NAK to X, see figure 8

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Figure 8 Join the tree in AMRIS if the neighbors are not on the tree

If a node is unable to find any potential parent node, it executes a branch reconstruction (BR)

process to rejoin the tree [5]

Characteristics of AMRIS:

Advantages: I) not have a loop, II) detects link disconnection by a beaconing mechanism

then locally repaired, and III) simplicity of this routing

Disadvantages: I) waste of bandwidth, II) slow rejoin scheme [5]

On-Demand Multicast Routing Protocol (ODMRP): this routing requires cooperation of

nodes wishing to send data to the multicast group to construct the multicast mesh

In ODMRP, when sources have data to send, but do not have routing or membership

information, periodically floods a join data packet throughout the network, then periodic

transmissions are used to update the routes, see figure 9

Figure 9 Periodically floods a join data packet throughput the network in ODMRP

Where blue circle represent multicast group member

Reverse path in ODMRP: receiver, broadcasts a Join Table (contains (sender S, next node N)

pairs) to all it’s neighbors, where next node N denotes the next node on the path from the group

member to the multicast sender S, see figure 10

Figure 10 Initialize reverse path in ODMRP

When node N becomes a forwarding group member, it transmits Join Table containing the

entry (S, M) where M is the next hop towards node S, see figure 11

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(a)

(b)

Figure 11 Reverse path in ODMRP

Where F marks a forwarding group member [6]

Characteristics of ODMRP:

Advantages: I) a network equipped with ODMRP does not require a separate unicast

protocol, II) redundant path (when they exist) can help deliver data when the primary path

becomes disconnected

Disadvantages: I) this routing don’t have explicit join or leave procedure, II) if in networks

GPS is available, the cost and additional weight of GPS [7]

Core-Assisted Mesh Protocol (CAMP): this routing uses mesh instead of tree approach for

multicast data forwarding, and this method classifies nodes in the network as duplex or simplex

members, or non-members

Duplex members are full members of multicast mesh, and simplex members are used to

create one-way connections between only sender nodes and the rest of the multicast mesh [8]

In CAMP cores are used to limit the flow of JOIN REQUEST packets, and they don’t need to

be part of mesh of their group

Join the group in CAMP: first checked whether any of my neighbors is a member of group,

because only members of the group can reply with a JOIN-ACK, see figure 12

Figure 12 Difference between member and non-member

Otherwise, sender propagates a JOIN REQUEST towards one of cores and attempts to reach

a member router by an expanding ring search see figure 13

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Figure 13 Sender attempts to reach a member router

Reverse path in CAMP: receiver node reviews it’s packet cache, periodically And determine

whether it receiving data packets from those neighbors which are on the reverse shortest path to

the source If not, the node sends either a HEARTBEAT or a PUSH JOIN message towards the

source along the reverse shortest path, see figure 14

Figure 14 Reverse path from destination (D) to source (S)

Characteristics of CAMP:

Advantages: I) don’t have a loop (loop-free), II) it builds massive mesh with growth of the

members, and its disadvantage: strongly depends on the underlying unicast protocol to work

correctly in presence of router failure and network partition [9]

For comparison between routing protocols, we summarize characteristics of t hem in table 1

Table 1 Comparison between routing protocols

Configuration

Loop free

Depends on Unicast

Periodic

Control packet flood

Tree

No Yes Yes Yes

Mesh Yes

No Yes Yes

Mesh Yes Yes Yes

No

Tree Yes

No Yes Yes

As seen from the table I that CAMP don’t have control packet flood, and AMRoute suffers

from loops

5 Conclusions

Comparison between the protocols is presented, in which is shown that between different

protocols only AMRoute suffers from loops, and only CAMP don’t have control packet flood

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6 References

[1] A Pathan, M Manavar, M Rabbi, M Alam, C Hong, “NAMP: Neighbor Aware Multicast

Routing Protocol for Mobile Ad Hoc Networks”, The international Arab Journal of Information

Technology, vol 5, no 1, pp.102-107, Jan 2008

[2] L Lovasz, “On the Ratio of Optimal Integral and Functional Covers”, Discrete Mathematics, vol

13, pp.383-390, 1975

[3] Z J Haas, “The Zone Routing Protocols (ZRP) for ad hoc networks”, Internet Draft, Nov 1997

[4] C C Chiang, M Gerla, L Zhang, “Shared Tree Wireless Network Multicast”, In Proceeding(s) of

IEEE IC3N, pp.28-33,1997

[5] C W Wu, Y C Tay, “AMRIS: a multicast protocol for ad hoc wireless networks”, In

Proceeding(s) of IEEE MILCOM’99, Atlantic City, pp.25-29, Nov 1999

[6] S J Lee, W Su, M Gerla, “Ad hoc wireless multicast with mobility prediction”, In Proceeding(s)

of IEEE ICCCN99, Boston, MA, OCT, pp.4-9, 1999

[7] S J Lee, M Gerla, C C Chiang, “On Demand Multicast Routing Protocols”, In Proceeding(s) of

IEEE WCNC’99, New Orleans, pp 1298-1302, Sept 1999

[8] J J Garcia-Luna-Aceves, E L Madruga, “A Multicast Routing Protocol for Ad-Hoc Networks”,

In Proceeding(s) of IEEE INFOCOM’99, New York, pp 784-792, March 1999

[9] J J Garcia-Luna-Aceves, E L Madruga, “The Core-Assisted Mesh Procol”, IEEE Journal on

Selected Area in Communication, vol 17, no 8, pp.1380-1394, Aug 1999