Download mMOM: Efficient Mobile Multicast Support Based on the Mobility of

mMOM: Efficient Mobile
Multicast Support Based
on the Mobility
of Mobile Hosts
YUNGOO HUH and CHEEHA KIM
Presented by
Kiran Kumar Bankupally
Agenda
Terminology
 Introduction
 Some implementation details
 mMOM: mobility based MObile
Multicast support
 Performance Evaluation
 Conclusions

Introduction
Necessity
 What is multicasting?

• sender sends a single datagram to the
multicast address, and the routers take
care of making copies and sending them
to all receivers that have registered
their interest in data from that sender.
• One way streaming media

Mobile IP!!!!
Mobile IP


Mobile IP is a Protocol that allows
mobile device users to move from
one network to another while
maintaining a permanent IP address
A Mobile IP consists of
• HA-Home Agent
• FA-Foreign Agent
Cont..

Home Agent
• stores information about mobile nodes
whose permanent address is in the
home agent's network

Foreign Agent
• stores information about mobile nodes
visiting its network care-of addresses,
which are used by Mobile IP
More on Mobile IP
Mobile IP protocol defines the following:
 an authenticated registration procedure by which
a mobile node informs its home agent of its careof-address
 an extension to ICMP Router Discovery, which
allows mobile nodes to discover prospective
home agents and foreign agents
 the rules for routing packets to and from mobile
nodes, including the specification of one
mandatory tunneling mechanism and several
optional tunneling mechanisms.
Mobile IP & multicast

Two types of multicasting
• Remote Subscription
• Bidirectional Tunneling

Relating this to the course.
Remote Subscription

MH moves to a foreign network, it
subscribes to the multicast group on
the foreign network.
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 Tunneling

When MH is away from its home
network, a bi-directional tunnel
between its HA and FA is set up.
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
mMoM
Mobility based mobile multicast
support
 Uses Registration Process
 FA maintains List of MH registrations

The 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 Evaluation
Analytical Model
 Analytical Results

Our Part

Assumptions
• 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….
• 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 Structure
Final 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……

The limiting Probabilities are!!!!!

Substituting that in the equation above
gives you
Where 0 < a, b < n+ 1


The 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 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.
Representation
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!!!!!!!
Equations

Thus the number of MHs in the FA is
given by
And then
these set of
equations
were given
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…

expected number of tunneling paths
to FA (nd)
Analytical Results

Assumptions
• Departure Rate (μ)=1
• ratio of the mobility rate to the reregistration 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
Conclusion

Improved efficiency in terms of
optimal delivery path and frequency
of multicast tree reconfiguration
Future Work

how to handle the co-located careof-address approach in mMOM