Content-Based Routing in Mobile Ad Hoc Networks Milenko Petrovic, Vinod Muthusamy, Hans-Arno...
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Transcript of Content-Based Routing in Mobile Ad Hoc Networks Milenko Petrovic, Vinod Muthusamy, Hans-Arno...
Content-Based Routing in Mobile Ad Hoc Networks
Milenko Petrovic, Vinod Muthusamy, Hans-Arno Jacobsen
University of Toronto
July 18, 2005
MobiQuitous 2005San Diego, CA
July 18, 2005 (MobiQuitous ’05) Content-Based Routing in MANET 2
Mobile Ad Hoc Networks Mobile Ad Hoc Network
Autonomous system of wireless mobile routers Characteristics
Varying bandwidth, latency, connectivity Mobile nodes, and highly dynamic topology
Applications Interactive games, location based advertising, mobile auctions,
financial services, selective information dissemination Communication primitives
Unicast Broadcast Multicast
July 18, 2005 (MobiQuitous ’05) Content-Based Routing in MANET 3
Content Based Routing in MANET Content Based Routing (a.k.a. publish/subscribe)
Unicast, multicast, broadcast No addresses loose coupling Supports large number of fine-grained groups
Expressive group membership
Applications Stock updates Mobile games Accident information dissemination
July 18, 2005 (MobiQuitous ’05) Content-Based Routing in MANET 4
Agenda
Background: Publish/Subscribe Model Wired distributed algorithm Benefits
Content-Based Routing Protocols Evaluation
Conclusions
July 18, 2005 (MobiQuitous ’05) Content-Based Routing in MANET 5
Publish/Subscribe Model
Publisher Publisher
Subscriber Subscriber
Subscriptions
Publications
NotificationNotification
IBM=84
MSFT=27 INTC=19 JNJ=58ORCL=12
HON=24
AMGN=58
Stock marketsNYSE
NASDAQTSX
Subscriptions:IBM > 85ORCL < 10JNJ > 60
BrokerNetwork
July 18, 2005 (MobiQuitous ’05) Content-Based Routing in MANET 6
Distributed Publish/Subscribe Advertisements
flooded Create ad tree
Subscriptions propagate along reverse ad path Create multicast
tree
Publications propagate along reverse sub path
PublisherSubscriber Subscriber
. . .. . .
Advertisements Subscriptions Publications
July 18, 2005 (MobiQuitous ’05) Content-Based Routing in MANET 7
Publish/Subscribe Benefits Simple interface
Decoupling of producers and consumers of data Address
Content-based routing Anonymity
Platform Space Time Representation (semantic)
Efficient data dissemination (scalability) Push model Multicast
July 18, 2005 (MobiQuitous ’05) Content-Based Routing in MANET 8
Content Based Routing in MANET Challenges
Highly dynamic network Fault tolerance, reliability
CBR (Content-Based Routing) Based on wired pub/sub protocols
FT-CBR (Fault-Tolerant CBR) Adapt to node mobility
RAFT-CBR (Reliable And Fault-Tolerant CBR) Guaranteed delivery
July 18, 2005 (MobiQuitous ’05) Content-Based Routing in MANET 9
CBR Protocol
Based on distributed pub/sub protocols Broadcast ads
Build connectivity graph Unicast subs
Setup multicast route
Soft state Beacon ads and subs Passive route repairs
P
S
Advertisements
Subscriptions
Publications
July 18, 2005 (MobiQuitous ’05) Content-Based Routing in MANET 10
Protocol Optimizations
Covering optimization Common in pub/sub systems Quench subsumed subscriptions
Most Covering (MC) optimization Forward subscription toward
existing multicast tree Tradeoff route length for
transmission and storage Builds more stable multicast
trees
P
Subscriptions
S1 S2
BS3
July 18, 2005 (MobiQuitous ’05) Content-Based Routing in MANET 11
FT-CBR Protocol
Routes broken due to node mobility
Hop by hop reliability
Proactive route repairs Hop by hop ACK of
messages On unack’d message
Expanding ring search to find destination node
P
S
Publication Acknowledgement
July 18, 2005 (MobiQuitous ’05) Content-Based Routing in MANET 12
RAFT-CBR Protocol
End to end reliability Difficult to ensure in CBR
No ad or sub state maintained Reuse underlying unicast routing
protocol
Assume publisher is reliable and knows subscriber set Include (dest, seq) pair in each
publication
Subscribers send cumulative ACKs and selective NACKs
Hierarchical ACK propagation
1 2 3 4 5 6P S
1 3 4 5
PS1
2 5 6 S2
Difficulties of RAFT-CBR
S3 S1
P
S2
Publication Acknowledgement
July 18, 2005 (MobiQuitous ’05) Content-Based Routing in MANET 13
Evaluation Simulation Environment
ns-2 network simulator Implemented CBR protocols
Shopping district scenario Vendors advertise to shoppers in a shopping district Shoppers interested in nearby stores
Parameters 50 mobile nodes (subscribers) Stationary publisher
Random publications
Metrics Delivery ratio Delivery delay Message load
July 18, 2005 (MobiQuitous ’05) Content-Based Routing in MANET 14
Subscriber Scalability
Delivery ratio 75% for CBR, ~100% for FT-CBR
Delivery delay Little change
Little change in multicast tree depth No recovery mechanisms (CBR)
Message cost FT-CBR high due to expanding ring search
40
50
60
70
80
90
100
10 20 30 40 50
Del
iver
y R
atio
(%
)
Subscribers
CBRFT-CBR
RAFT-CBR 0
0.2
0.4
0.6
0.8
1
10 20 30 40 50
Del
ay (s
)
Subscribers
CBRFT-CBR
RAFT-CBR
0
10000
20000
30000
40000
50000
60000
70000
80000
10 20 30 40 50M
essa
ges
Subscribers
RoutingControl
SubscriptionsDataCBR
FT-CBRRAFT-CBR
July 18, 2005 (MobiQuitous ’05) Content-Based Routing in MANET 15
Effects of Optimizations
Covering and most-covering (MC) optimizations
MC improves delivery by 10% points … Benefits increase with more subscribers
... but increases delay and message load Costs diminish with larger multicast trees
Covering significantly reduces message load
0
0.005
0.01
0.015
0.02
0.025
0.03
0.035
0.04
0.045
0.05
10 20 30 40 50
Del
ay (s)
Subscribers
CBR CBR w/ MC
CBR w/o covering 40
50
60
70
80
90
100
10 20 30 40 50
Deliv
ery
Rat
io (%
)
Subscribers
CBR CBR w/ MC
CBR w/o covering
0
5000
10000
15000
20000
25000
30000
35000
40000
10 20 30 40 50M
essa
ges
Subscribers
RoutingControl
SubscriptionsDataCBR
CBR w/ MCCBR w/o covering
July 18, 2005 (MobiQuitous ’05) Content-Based Routing in MANET 16
Interest Locality
Vary number of subscribers with static interest Leads to less stable and larger multicast trees
MC optimization has largest impact Makes more stable (but longer) multicast trees
40
50
60
70
80
90
100
0 25 50 75 100
Del
iver
y R
atio
(%
)
Interest Locality (%)
CBR CBR w/ MC
CBR w/o covering
0
0.01
0.02
0.03
0.04
0.05
0.06
0 25 50 75 100
Del
ay (s)
Interest Locality (%)
CBR CBR w/ MC
CBR w/o covering 0
5000
10000
15000
20000
25000
30000
35000
40000
0 25 50 75 100M
essa
ges
Interest Locality (%)
RoutingControl
SubscriptionsDataCBR
CBR w/ MCCBR w/o covering
July 18, 2005 (MobiQuitous ’05) Content-Based Routing in MANET 17
Related Work
Little research into fully content-based pub/sub protocols in MANET
Wired CBR protocols Typically assume stable acyclic topologies
Multicast in MANET MAODV, DVMRP, ODMRP Group-based (not content-based)
Reliability protocols not applicable to content-based
July 18, 2005 (MobiQuitous ’05) Content-Based Routing in MANET 18
Conclusions Publish/Subscribe content based routing
Appropriate for mobile networks
No “best” protocol CBR: Low delay, message cost
Streaming media applications FT-CBR: Adapts to dynamic environments
High mobility applications RAFT-CBR: Reliable
Financial applications
Future work More protocols
Combine best of existing protocols More experiments
Mobile subscribers, realistic scenarios, etc.
July 18, 2005 (MobiQuitous ’05) Content-Based Routing in MANET 19
Content-Based Routing in Mobile Ad
Hoc Networks
Q&A
www.msrg.utoronto.ca