Transcript ppt - MMLab

Ad Hoc Networking via Named Data
Michael Meisel, Vasileios Pappas, and Lixia Zhang
UCLA, IBM Research
MobiArch’10, September 24, 2010
2011. 3. 13
Shinhaeng Oh
([email protected])
1/22
CONTENTS
• Background
– Internet Protocol vs. Named Data
• Existing Solutions for mobile networks
– Ad-Hoc Networking over IP
– Limitation of IP-Routing
• New Direction for mobile networks
– NDN for Ad-Hoc Networking
– Design Example : LFBL
• Conclusion
2/22
Introduction
• TCP/IP and CCN Protocol Stacks
– Replace packets with Data Objects or Interests
– Replace Addresses with Names of Objects
3/22
Ad-Hoc Networking over IP
2
1
212.123.3.214
201.239.0.101
3
198.102.182.104
5
4
112.191.203.117
162.201.193.210
1. Each node is assigned an IP address
4/22
Ad-Hoc Networking over IP
2
1
212.123.3.214
201.239.0.101
3
198.102.182.104
5
4
112.191.203.117
162.201.193.210
2. Applications communicate by sending data to specific
destination addresses
5/22
Ad-Hoc Networking over IP
2
1
212.123.3.214
201.239.0.101
3
198.102.182.104
5
4
112.191.203.117
162.201.193.210
3. When node move, determine a single best path to the given
destination IP, and delivers data
6/22
Limitations of the IP-Routing (1)
• Difficult to assign IP addresses (moving nodes)
– IP addresses management is tightly controlled
– It requires infrastructure support (e.g. DHCP)
 ad-hoc networks need infrastructure-free !!
• In mobile, IP address is less meaningful
– Wired networks, IP represent topology location
– But, ad-hoc network do not have fixed location
– Temporary unique identifier for device is needed
SNU: 147.46.174.xx
MIT: 18.9.22.xx
7/22
NDN for Ad-Hoc Networking (1)
• Assign IP address to each nodes --No longer needs
– To forward interests & data packets,
– Nodes can use application data names directly
forward or broadcast
interest
interest
8/22
Limitations of the IP-Routing (2)
• Data is invisible in today’s IP-centric architecture
source
destination
– It’s sub-optimal delivery
• Accuracy of routing state maintained at each node
Overhead to keep this state consistent --tradeoff
– High node mobility
– Constant movement in the aggregate at a large network
9/22
NDN for Ad-Hoc Networking (2)
• Caching (traditional approach)
– Ideally, each cached object has to be retrieved in its
entirety from the same caching node.
– But, images & audios & videos cannot fit within one packet
– Transparent caching techniques work only in static network
• Caching (NDN)
– Intermediate node can forward to request node any part of
file
subsequent
request
10/22
Limitations of the IP-Routing (3)
• Receivers are in a better position to make forward
decision than senders
– In broadcast channel, nodes can hear the transmission
– To keep all neighbors’ movement and connectivity changes
will increase the routing table update overhead
11/22
NDN for Ad-Hoc Networking (3)
• Interest packets can be forwarded multiple path
– More than one direction returns the request data
– A node can evaluate which path gives the best performance
– Send future Interest for same data source in that direction
– Remove critical dependency on pre-computed single paths
12/22
Design Example: LFBL
• LFBL: Listen First, Broadcast Later
• Uses a variation of NDN’s 3-way exchange
– Name prefix announcements
Response
– Interest forwarding
– Data return
REQUEST
Name of application data
Response
13/22
Design Example: LFBL
• LFBL: Listen First, Broadcast Later
• Uses a variation of NDN’s 3-way exchange
– Name prefix announcements
– Interest forwarding
– Data return
ACK
Destination
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Design Example: LFBL
• LFBL: Listen First, Broadcast Later
• Uses a variation of NDN’s 3-way exchange
– Name prefix announcements
– Interest forwarding
– Data return
2
Destination
ACK
1
15/22
Design Example: LFBL
• LFBL: Listen First, Broadcast Later
• Uses a variation of NDN’s 3-way exchange
– Name prefix announcements
– Interest forwarding
– Data return
Destination
ACK
1
2
16/22
Design Example: LFBL
• LFBL: Listen First, Broadcast Later
• Uses a variation of NDN’s 3-way exchange
– Name prefix announcements
– Interest forwarding
– Data return
ACK
Destination
17/22
Design Example: LFBL
• LFBL: Listen First, Broadcast Later
• Uses a variation of NDN’s 3-way exchange
– Name prefix announcements
– Interest forwarding
– Data return
Destination
ACK
1
2
3
18/22
Design Example: LFBL
• LFBL: Listen First, Broadcast Later
• Uses a variation of NDN’s 3-way exchange
– Name prefix announcements
– Interest forwarding
– Data return
ACK
Destination
19/22
Performance Evaluation
• Implemented LFBL in QualNet network simulator
– Effect of % of mobile nodes
– Move at a fixed rate of 30m/s (random waypoint mobility)
various contents concurrently? 20/22
Conclusion
• Frequent changes in topology had a direct impact
on the performance of current protocols
• Designed a new forwarding protocol: LBFL
– For highly dynamic multi-hop wireless networks
– Distributed forwarding capability with essentially no routing
protocol
• Through named data networking approach,
– We can sketched out promising architectural direction to
develop effective and efficient solution for ad-hoc networks
21/22
QnA
22/22
Related Work: DSDV, AODV
• Destination-Sequenced Distance-Vector Routing
(DSDV) is a table-driven routing scheme for ad hoc
mobile networks based on Bellman-Ford algorithm
– Each entry in the routing table contains a sequence
number, they generally even if a link is present, odd used
• For example the routing table of Node A in Network
Destination
Next Hop
# of Hops
Seq. number
Install Time
A
A
0
A 46
001000
B
B
1
B 36
001200
C
B
2
C 28
001500