Ad Hoc Multicast Routing
Category of Ad Hoc Multicast
Routing Protocols
Underlying Data Delivery Structure
Flooding-Based
Tree-Based
Mesh-Based
Broadcast
AMRIS
CAMP
MCEDAR
MAODV
OMDRP
ADB
LAM
FGMP
AMROUTE
2
Hybrid-Based
Category of Ad Hoc Multicast
Routing Protocols
State Maintenance
Unconstrained
Stateless
Constrained
Tree-based scheme
DDM
AMROUTE
Mesh-based scheme
PBM
PAST-DM
LGT
POMA
3
Flooding - Broadcasting
Results in minimal state retention and high
reliability which makes it a viable candidate for
multicast protocols in very dynamic MANET.
Heavy-handed in terms of overhead
Obtains the best results in terms of reliable
delivery
Problem
Broadcast storm[12]
4
AMRIS: Ad Hoc Multicast Routing Protocol
Utilizing Increasing Id-Numbers
msm-id = Sid = 0
 On-demand
 Shared tree
X
Tree is rooted at special
node called Sid (Smallest
Id) : one of sources
increasing msm-id
(multicast session
member id, assigned
dynamically)
 Initiate a session
11
14
18
21
24
28
31
34
38
NEW-SESSION msg
(Sid’s msm-id, metrics)
 Join a session,
unicast JOIN-REQ to its
potential parent node
5
MAODV: Multicast Ad Hoc On-Demand
Distance Vector Protocol
 Based on unicast AODV
 Discovers multicast route
on-demand using a
broadcast route discovery
mechanism
 Route discovery
 RREQ
• To join a group,
• or to send to a group if no
route
6
ODMRP: On-demand Multicast Routing
Protocol
Mesh-based, soft state
Forwarding group: a subset of nodes forwards
the multicast packets
Join reply
receiver
source
Join query
receiver Join query
7
DDM: Differential Destinations Multicast
Explicit Header
All destinations are placed in the packet headers
Data Forwarding
Referring underlying unicast routing table
Two modes
Stateless
Soft state
Membership Management
Source controls multicast group membership
8
LGT: Location Guided Tree
 A small group multicast
schemes based on
packet encapulation
 Builds an overlay
multicast packet
distribution tree on top
of the underlying
unicast routing protocol
n2
n1
n3
S
n4
n5
n7
n6
Using the geometric
location information
without knowing the
global network topology
Construct a tree with
geometrically shorter
tree edges
n8
9
Outstanding Projects
UCLA Wireless Adaptive Mobility Laboratory
Computer Communication Research Group at
the University of California, Santa Cruz
Rice University Monarch Project
Wireless and Mobile Ad Hoc Networks at
University of Southern California
10
Geocasting
Geocast Region – A specified geographical area
A variant of the conventional multicasting
problem
Deliver Packets to a group of nodes in Geocast
Region.
The location information of all the nodes will be
known by GPS
Whenever one node in Geocast region receives
message from outside, it will flood it to all its
neighbors.
11
LBM: Location-based Multicast
Extend LAR for geocasting
Flooding approach
LBM Scheme 1
LBM Scheme 2
12
VDG: Voronoi Diagram based Geocasting
 To enhance the success rate
and decrease the hop count and
flooding rate of LBM
 Carve up the whole plane into
several Voronoi regions based
on the source and its neighbor
 Only neighbor nodes (B, E)
which are in the same Voronoi
region as the Geocast Region
will be selected to receive the
message from Source.
 VDG reduces the flooding rates
of LBM Scheme 1
13
PBM: Position Based Multicast
 Design Goal
 Minimize total hops to all destinations
 Minimize length of path to individual destination
 Sender has the knowledge (assumptions)
 Position of destination(s)
 Position of neighbor(s)
 It’s own position
 Greedy multicast forwarding
 Each destination exists at least one neighbor which is closer to
that destination than the forwarding node itself.
Minimize the expression
Greedy Multicast Forwarding
K: Forwarding node
N: Set of all neighbors of K
W: Set of all subsets of N
Z: Set of all destinations
d(x,y): distance between x and y
min mw d (m, z )
| w|

zZ
f ( w)  
 (1   )
|N|
 zZ d (k , z)
No. of neighbors that
packet is transmitted to
14
Remaining distance to all destinations
Energy Efficiency
 Power-Aware and Energy-Efficient Broadcast and
Multicast Infrastructure
Solution 1: Lifetime of a bottleneck node is improved by
reassigning its farthest children to other nodes in the tree
with the goal of improving the lifetime of the multicast
tree.
Solution 2: finding a tree with the least consumed power
becomes a conventional optimization problem on a graph
where the weighted link cost corresponds to the
transmission power required for transmitting a packet
between the two nodes of the link
 Energy Consumption from Retransmission at the
Data-Link Layer
Solution: maximizing sleep mode operation supported by
the lower level protocol
15