mMOM: Efficient Mobile Multicast Support Based

on the Mobilityof Mobile Hosts

YUNGOO HUH and CHEEHA KIMPresented by

Kiran Kumar Bankupally

AgendaAgenda

TerminologyTerminology IntroductionIntroduction Some implementation detailsSome implementation details mMOM: mobility based MObile mMOM: mobility based MObile

Multicast supportMulticast support Performance EvaluationPerformance Evaluation ConclusionsConclusions

IntroductionIntroduction

Necessity Necessity What is multicasting?What is multicasting?

• sender sends a single datagram to the sender sends a single datagram to the multicast address, and the routers take multicast address, and the routers take care of making copies and sending them care of making copies and sending them to all receivers that have registered to all receivers that have registered their interest in data from that sender.their interest in data from that sender.

• One way streaming mediaOne way streaming media Mobile IP!!!!Mobile IP!!!!

Mobile IPMobile IP

Mobile IP is a Protocol that allows Mobile IP is a Protocol that allows mobile device users to move from mobile device users to move from one network to another while one network to another while maintaining a permanent IP addressmaintaining a permanent IP address

A Mobile IP consists ofA Mobile IP consists of• HA-Home AgentHA-Home Agent• FA-Foreign AgentFA-Foreign Agent

Cont..Cont..

Home AgentHome Agent• stores information about mobile nodes stores information about mobile nodes

whose permanent address is in the whose permanent address is in the home agent's networkhome agent's network

Foreign AgentForeign Agent• stores information about mobile nodes stores information about mobile nodes

visiting its network care-of addresses, visiting its network care-of addresses, which are used by Mobile IP which are used by Mobile IP

More on Mobile IPMore on Mobile IP

Mobile IP protocol defines the following:Mobile IP protocol defines the following: an authenticated registration procedure by which an authenticated registration procedure by which

a mobile node informs its home agent of its care-a mobile node informs its home agent of its care-of-address of-address

an extension to ICMP Router Discovery, which an extension to ICMP Router Discovery, which allows mobile nodes to discover prospective allows mobile nodes to discover prospective home agents and foreign agentshome agents and foreign agents

the rules for routing packets to and from mobile the rules for routing packets to and from mobile nodes, including the specification of one nodes, including the specification of one mandatory tunneling mechanism and several mandatory tunneling mechanism and several optional tunneling mechanisms. optional tunneling mechanisms.

Mobile IP & multicastMobile IP & multicast

Two types of multicastingTwo types of multicasting• Remote SubscriptionRemote Subscription• Bidirectional TunnelingBidirectional Tunneling

Relating this to the course.Relating this to the course.

Remote SubscriptionRemote Subscription

MH moves to a foreign network, it subscribes to the multicast group on the foreign network.

Cont…..Cont…..

Advantages:-• option is simple and provides optimal

routing efficiency Disadvantages:-

• will overload the multicast routers for multicast tree management

• suffer from packet losses at roaming, owing to the set-up time associated with multicast subscription (later it was rectified)

Bi directional TunnelingBi directional Tunneling

When MH is away from its home network, a bi-directional tunnel between its HA and FA is set up.

Cont…..Cont…..

Advantages:-• guarantees multicast packet delivery

against roaming • handles the mobility of both the source

and recipients Disadvantages:-

• the routing path for packet delivery may be far from optimality

• tunnel convergence problem can occur

mMoMmMoM

Mobility based mobile multicast Mobility based mobile multicast supportsupport

Uses Registration ProcessUses Registration Process FA maintains List of MH registrationsFA maintains List of MH registrations

The ProcessThe Process

MH moves first to a foreign network, a bi-directional tunnel to its HA is set up in mMOM as the BT option

If MH does not switch its foreign network, it must perform re-registration to its HA via the FA again before the expiration of its lifetime

Implies Temporal Locality in FA Network

Performance EvaluationPerformance Evaluation

Analytical ModelAnalytical Model Analytical ResultsAnalytical Results

Our PartOur Part

AssumptionsAssumptions• single multicast group with one source• source is a fixed host and other

members of the multicast group are MHs.

• Group membership does not change dynamically and there are M MHs belonging to the multicast group

• each network has only one FA

Cont….Cont….

• MH’s re-registration time and residence time in FA are exponential random variables with parameters τ and μ, respectively.

• Networks are homogenous and are distributed in n × n matrix with each node has exactly four neighbors.

• MH is assumed to move to one of four directions randomly with equal probability

Our network StructureOur network Structure

Final AssumptionFinal Assumption

• the interarrival time of MHs at a FA is exponentially distributed with mean rate λ.

λ = μ/(n2 − 1)(first proof)

Markov chain describing the behavior of MH under the n × n homogenous networks

Here we go……Here we go……

The limiting Probabilities are!!!!!The limiting Probabilities are!!!!!

Substituting that in the equation above Substituting that in the equation above gives yougives you

Where 0 < a, b < n+ 1

The given diagram reduces toThe given diagram reduces to

Markov chain for describing the arrival rate of single MH to FA positioning (a, b) under the n × n homogenous networks.

Back to the problemBack to the problem

Each state is represented by (α, β)

• α indicates the number of MH serviced by the FA,

• β is either 0 (denoting that the FA is not involved in

the multicast service) 1 (denoting that the FA is already in the

multicast service)

Markov chain describing the behavior of FA under mMOM.

RepresentationRepresentation

Markov chain describing the behavior of FA under mMOM.

By assuming

Now the equations reduce to

the probability Pk in nothing but the steady state probability in M/M/∞//M model shown!!!!!!!

EquationsEquations

Thus the number of MHs in the FA isThus the number of MHs in the FA is

given bygiven by

And then these set of equations were given

More……More……

multicast tree management overhead (Em)• number of join and leave operations per

unit time, the overhead in RS, BT, MoM, and mMOM can be expressed as follows

And more…And more…

expected number of tunneling paths to FA (nd)

Analytical ResultsAnalytical Results

AssumptionsAssumptions• Departure Rate (Departure Rate (μ)=1=1• ratio of the mobility rate to the re-

registration rate (MRR)MRR= μ/τ

The tree management overhead

The expected number of tunneling paths

The tree management overhead

The expected number of tunneling paths in FA

The total cost CT

ConclusionConclusion

Improved efficiency in terms of optimal delivery path and frequency of multicast tree reconfiguration

Future WorkFuture Work

how to handle the co-located care-of-address approach in mMOM