Survey on Peer to Peer Data Dissemination over MANET

1
Survey on Peer to Peer Data Dissemination over
MANET

• Kun Chen
• Ying Jian

2
Motivation

• P2P VS Mobile Ad Hoc Network
• Similar
• Self-organization
• Decentralization
• Different
• Most P2P depend on application connections among
  peers, based on application
• Most MANET overlay dynamically formed among
  nodes, based on network topology

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Motivation

• Mapping
• P2P to Application layer
• Unicast with virtual broadcast
• Static nodes
• MANET to Network layer
• Physical broadcasting
• Dynamic nodes
• P2P over MANET!!

4
Our Idea

• Data dissemination in P2P over MANET
• Data routing Layer Discussion
• Broadcast over Broadcast
• Content-Driven over Broadcast
• Data delivery Transmission Discussion
• Synchronous VS Asynchronous
• Segmentation VS Full-packet

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Data Routing Layer Discussion

• Broadcast Over Broadcast
• Broadcast-Like MANET protocols (network layer)
• AODV (Unicast)
• MAODV (tree-based multicast)
• ODMRP (mesh-based multicast)

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AODV
Y
Z
S
E
F
B
C
M
L
J
A
G
H
D
K
I
N
Represents a node that has received RREQ for D
from S
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AODV
Y
Broadcast transmission
Z
S
E
F
B
C
M
L
J
A
G
H
D
K
I
N
Represents transmission of RREQ
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AODV
Y
Z
S
E
F
B
C
M
L
J
A
G
H
D
K
I
N
Represents links on Reverse Path
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Reverse Path Setup in AODV
Y
Z
S
E
F
B
C
M
L
J
A
G
H
D
K
I
N

• Node C receives RREQ from G and H, but does not
  forward
• it again, because node C has already forwarded
  RREQ once

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Reverse Path Setup in AODV
Y
Z
S
E
F
B
C
M
L
J
A
G
H
D
K
I
N
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Reverse Path Setup in AODV
Y
Z
S
E
F
B
C
M
L
J
A
G
H
D
K
I
N

• Node D does not forward RREQ, because node D
• is the intended target of the RREQ

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Forward Path Setup in AODV
Y
Z
S
E
F
B
C
M
L
J
A
G
H
D
K
I
N
Forward links are setup when RREP travels
along the reverse path Represents a link on the
forward path
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ODMRP
Join Query Join Reply
R
S
R
R
R
R
1. S floods a Join Query to entire network to
refresh membership. 2. Receiving node stores the
backward learning into routing table and
rebroadcasts the packet. 3. Finally when query
reaches a receiver creates a Join Reply and
broadcasts its to its neighbors. 4. Node
receiving the Join Reply checks whether the next
node id in Join Reply matches it own. If yes , it
is a part of the forwarding group, sets its
FG_FLAG and broadcasts its join reply built upon
matched entries. 5. Join Reply is propagated by
each forwarding group member until it reaches
source via a shortest path. 6. Routes from
sources to receivers builds a mesh of nodes
called forwarding group.
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ODMRP

• Route Table
• Forwarding Group Table

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Broadcast Over Broadcast
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Gnutella Protocol
Scenario Joining Gnutella Network
Gnutella Network

• The new node connects to a well known Anchor
  node.
• Then sends a PING message to discover other
  nodes.
• PONG messages are sent in reply from hosts
  offering new connections with the new node.
• Direct connections are then made to the newly
  discovered nodes.

New
PING
PING
PING
PONG
PING
PING
A
PING
PING
PONG
PING
PING
PING
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Gnutella Protocol
Scenario Searching for a File
Gnutella Network

• A node broadcasts its QUERY to all its peers who
  in turn broadcast to their peers.
• Nodes route QUERYHITs along the QUERY path back
  to the sender containing file location details.
• To download files a direct connection is made
  using details of the host in the QUERYHIT
  messages.

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Drawbacks for Broadcast Over Broadcast

• Inefficient
• Bandwidth consuming
• Complexity O(n2)
• Shortest path in P2P may not be shortest in MANET

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Data Routing Layer Discussion

• Content-Driven over Broadcast
• Nodes build content summary of their data
• Nodes disseminate content summary to appropriate
  peers
• A peer can use these summaries to determine which
  of its peer can provide its requested data

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Content-Driven routing and data dissemination

• When a peer receives a query, it search its local
  content, and also the stored content synopses of
  other peers
• If no match found in local content, the peer
  forwards the query to its immediate peers that
  may contain the requested object.
• Three ways to disseminates content synopses

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Content-Driven routing and data dissemination
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Three ways to disseminates content synopses

• node C propagates only its local synopsis to all
  peers one hop away

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Three ways to disseminates content synopses

• C propagates its local synopsis to selected
  immediate and remote peers.

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Three ways to disseminates content synopses

• C propagates both its local and stored remote
  synopses to selected immediate and remote peers

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Further discussion on Content-Driven protocol

• This protocol has some features of cross-layer
  data dissemination mechanism. Because it makes
  use of immediate peers
• It can make use of the knowledge from the
  physical network structure

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Data Dissemination Synchronous VS Asynchronous

• Synchronous Data Dissemination
• Mobile device will have worse resources than
  wired network
• Week connectivity can be enhanced by dynamic data
  routing or flooding
• Algorithms require connected available sender and
  receiver

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Data Dissemination Synchronous VS Asynchronous

• Asynchronous Data Dissemination
• In local ad hoc network, document can be
  available as long as it can be maintained by
  other neighbors
• Also available for those nodes which are
  currently offline
• Mobility can help transport information between
  different local ad hoc networks

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Data Dissemination Synchronous VS Asynchronous

• Asynchronous Data Dissemination Model
• Four Roles
• Proactive provider
• Reactive provider
• Proactive consumer
• Reactive consumer

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Example
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Data delivery Transmission Discussion

• Segmented data dissemination
• Traditionally, data(i.e. files, objects) are
  transmitted as a whole packet
• Full-packet data dissemination does not fit well
  in MANET environment.
• Solution get different pieces of the desired
  data from different peers.

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Segmented data dissemination

• Suppose we want to share a very popular data file
  D in the network.
• Scheme
• supplying peers that possess the entire data D.
  They periodically broadcast the pieces of D in
  their transmission range.
• Requesting peers Listen to the packet broadcast
  from different supplying peers

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Segmented data dissemination

• Scheme
• Both supplying and requesting peers will relay
  packets that they received
• A requesting peer becomes a supplying peer after
  it received all pieces of D

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Segmented data dissemination
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Segmented data dissemination

• Improved by exploiting Tornado Coding

Original Data
Segmented Data
Cut into n pieces
Segmented by Tornado Coding
encode into m pieces
Any k (gtn) pieces can restore the original data.
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Conclusion

• In this survey, we focus on data dissemination in
  P2P over MANET from two points of view
• Layer view data routing
• Broadcast over Broadcast
• Content-Driven over Broadcast
• Transmission view data delivery
• Synchronous VS Asynchronous
• Segmentation VS full-packet

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Thank you!

• Questions?