Post on 07-Jan-2016
description
GEOGRAPHIC ROUTING PROTOCOLS IN WIRELESS
SENSOR NETWORKS FOCUS ON REAL TIME ROUTING AND PROTOCOLS SUPPORTING MOBILITY
Imane BENKHELIFA
Research Associate, CERIST, Algeria
1st year PhD Student, USTHB, Algeria
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OUTLINE
Routing Protocols
Cliassification of Routing Protocols
Geographic Protocols
QoS Routing Protocols
MultiPath Protocols
Routing Protocols supporting Mobility
Routing Protocols with Localization Errors
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ROUTING PROTOCOL
Design Constraints for routing in WSN: Autonomy: nodes make decisions
Energy Efficiency: Prolonging network life time while maintaining a good grade of connectivity
Scalability: works with a large amount of nodes
Resilience: if some nodes stop operating, an alternative route should be discovered
Device heterogeneity: the use of nodes with different processors, transceivers, power units or sensing components
Mobility Adaptability: supports the mobility of nodes (sinks, events…)
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ROUTING PROTOCOL
Additional constraints for certain applications such as “Emergency Response”:
Stateless Architecture: it does not require routing table minimum memory
Soft Real-time: minimum delay
QoS Routing and Congestion Management : avoids congestion, re-routes packets, minimum control overhead
Traffic Load Balance: multi path, concurrent routes
Localized behavior: only delay changes will be sent to neighbors
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OUTLINE
Routing Protocols
Cliassification of Routing Protocols
Geographic Protocols
QoS Routing Protocols
MultiPath Protocols
Routing Protocols supporting Mobility
Routing Protocols with Localization Errors
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CLASSIFICATIONRouting
Network Structure
Flat
DD,SPIN,RR,MCFA
Hierarchic
TEEN,LEACH,TTDD
Geographic
SPEED,GOAFR,GEER
Protocol operations
Negociation
SPIN
Query
DD,Rumor
QoS
SAR,SPEED,MMSPEED
Multi-Path
Braided, N to 1
Coherence
Rumor
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OUTLINE
Routing Protocols
Cliassification of Routing Protocols
Geographic Protocols
QoS Routing Protocols
MultiPath Protocols
Routing Protocols supporting Mobility
Routing Protocols with Localization Errors
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GEOGRAPHIC ROUTING IN WSN
Motivations of Using Geographic Routing Approach in WSNs
Simplicity: simple calculations
Stateless: memory conservation
Autonomy: nodes make decisions
Energy Efficiency: prolonging network life time while maintaining a good grade of connectivity
Scalability: works with a large amount of nodes
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GEOGRAPHIC ROUTING IN WSN
Forwarding techniques in geographic routing are: Compass routing(C), GRS(G), MFR(M) and NFP(N)
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GEOGRAPHIC ROUTING IN WSN
Greedy Algorithms: choosing among neighbors the nearest to the sink (the Euclidian distance is a metric of choosing), the process repeats until the packet reaches the final destination,
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GEOGRAPHIC ROUTING IN WSN
Drawback: if the current holder has no neighbors closer to the destination than itself !!!!!
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GEOGRAPHIC ROUTING IN WSN GAF (Geographic Adaptive Fidelity):
Forms a virtual grid of the covered area Three node states: Discovery, Active and Sleep Each node associates itself with a cell in the grid based on its
location Nodes associated with the same cell are equivalent Some nodes in an area are kept sleeping to conserve energy Nodes change state from sleeping to active for load balancing
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GEOGRAPHIC ROUTING IN WSN
GAF Advantages: Increase the lifetime of the network significantly Considered to be hierarchical protocol
Each sub-region is a cluster Representative node is a cluster head
GAF Disadvantages: Does not perform any data aggregation Not very scalable Overhead of forming the grid Only the active nodes sense and report data data
accuracy is not very high
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OUTLINE
Routing Protocols
Cliassification of Routing Protocols
Geographic Protocols
QoS Routing Protocols
MultiPath Protocols
Routing Protocols supporting Mobility
Routing Protocols with Localization Errors
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QOS ROUTING PROTOCOLS IN WSN
Motivations of Using QoS Routing Approach in WSNs
Ensure Quality of Service in terms of :
Delay Bandwith Energy Load Balancing
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QOS ROUTING PROTOCOLS IN WSN
SPEED:
Aims to reduce the End-to-End deadline miss ratio
Supposes that E2E Deadlines are proportional to the distance between the source and the destination using feed-back control
Guarantees deadline by maintaining a packet delivery speed across the network.
Velocity = Distance (s,d) / required deadline
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QOS ROUTING PROTOCOLS IN WSN
SPEED:
The forwarding nodes are calculated from the neighbor nodes having to be at least k distance closer to the destination
If no speed matches, a neighborhood feed-back determines whether to drop the packet or to re-route it
S F DR
K
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OUTLINE
Routing Protocols
Cliassification of Routing Protocols
Geographic Protocols
QoS Routing Protocols
MultiPath Protocols
Routing Protocols supporting Mobility
Routing Protocols with Localization Errors
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MULTIPATH GEOGRAPHIC ROUTING IN WSN
Motivations of Using Multipath Routing Approach in WSNs
Reliability and Fault-Tolerance
Load Balancing and Bandwidth Aggregation
QoS Improvement
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MULTIPATH GEOGRAPHIC ROUTING IN WSN
MMSPEED (Multi path Multi SPEED): Introduces multiple speed levels (layers) to guarantee
timeliness packet delivery Each packet is assigned to a speed layer and then
placed in a queue High priority before low priority Source determines for each packet the speed regarding
the destination and its specific E2E deadline If an intermediate node perceives that this packet
cannot meet its specific deadline, the intermediate selects another speed layer
Reliability is guaranteed by controlling active paths and sending multiple copies
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MULTIPATH GEOGRAPHIC ROUTING IN WSN
MMSPEED (Multi path Multi SPEED):
A
B
C
D = distance A-C – distance B-C
distance
A-B
distance B-C destination
Geographic progress that can be made towards the destination by selecting node B as the next forwarder
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MULTIPATH GEOGRAPHIC ROUTING IN WSN
Challenges:
The main disadvantage lies in the cost of maintaining the paths.
This cost comprises in memory resources and network overhead so not suitable for networks critically by their reduced batteries.
However, they become necessary when reliability is a strong requirement
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OUTLINE
Routing Protocols
Cliassification of Routing Protocols
Geographic Protocols
QoS Routing Protocols
MultiPath Protocols
Routing Protocols supporting Mobility
Routing Protocols with Localization Errors
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ROUTING PROTOCOLS SUPPORTING MOBILITY IN WSN
Motivations of Using Routing Approach in WSNs with mobile sinks
Mobile sinks prolong the networks lifetime
Load Balancing and Bandwidth Aggregation
QoS Improvement
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ROUTING PROTOCOLS SUPPORTING MOBILITY IN WSN
TTDD (Two Tier Data Dissemination): Static sensors vs Mobile sinks Each active source creates a grid over the static
network with grid points acting as dissemination nodes. A mobile sink sends out a locally controlled flood that
discovers its nearest dissemination point.
D
S
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ROUTING PROTOCOLS SUPPORTING MOBILITY IN WSN
ALURP (Adaptive Local Update-based Routing Protocol): The adaptive area is constructed as the circle (VC, Dvc,sink).
DN
VC
Area B
Area A
DNA
DNB
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ROUTING PROTOCOLS SUPPORTING MOBILITY IN WSN
Problem: When the sink moves
toward the VC, the DN still keep the previous location of the sink and therefore will send the packet to a wrong place, because sink informs only the new area about its new location.
Solution:• Inform the former adaptive area but not the current
adaptive area to flush the topology information of the sink.
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ROUTING PROTOCOLS SUPPORTING MOBILITY IN WSN
ALURP Advantages:
Saves energy and keeps communication with sensors and sink thanks to the adaptive area.
The destination area can be expressed by its radius R.
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ROUTING PROTOCOLS SUPPORTING MOBILITY IN WSN
ALURP Drawbacks:
How to inform only the former adaptive area but not the current adaptive area ?????
DN may excessively consume energy, because source always sends data to the DN instead of the sink, which can be a bottleneck !!!!!!
If the destination area is too small and sink changes frequently its position too much of energy consumption by sensors to update routes !!!!!
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ROUTING PROTOCOLS SUPPORTING MOBILITY IN WSN
Energy-Efficient Routing in MWSN using Mobility Prediction: Mobile sink estimates and tracks its state (location,
velocity, acceleration) from noisy measurements with a kalman filter.
The source predicts the location of the mobile sink
The state of the predictor is updated by receiving STATE-UPDATE from the mobile sink.
The STATE-UPDATE is only sent when the Euclidean norm of the error between the predicted state and the estimated state by Kalman Filter exceeds a pre-defined threshold.
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ROUTING PROTOCOLS SUPPORTING MOBILITY IN WSN
The STATE-UPDATE and DATA messages are forwarded in a multi hop fashion
Uses greedy forwarding.
ELASTIC:
A
-A node uses greedy forwarding-The mobile sink broadcasts its new position every 1 m -Each node listens to the transmission of his successor and detects the change of the sink position and changes it for its next transmission- The process repeats until the source node
B
ROUTING PROTOCOLS SUPPORTING MOBILITY IN WSN
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OUTLINE
Routing Protocols
Cliassification of Routing Protocols
Geographic Protocols
QoS Routing Protocols
MultiPath Protocols
Routing Protocols supporting Mobility
Routing Protocols with Localization Errors
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ROUTING PROTOCOLS WITH LOCALIZATION ERRORS
Motivations of Using Routing protocols with Localization Errors
Nodes’ positions are not always accurate
If the packet contains a wrong position , the packet will not reach its destination
QoS Improvement by introducing localization errors in routing decisions
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ROUTING PROTOCOLS WITH LOCALIZATION ERRORS
ELLIPSE The region is defined by an ellipse source position, sink
position, distance between them, an ellipse factor “ l ”. All nodes in the ellipse region and those who receive
msg, forward it with a probability “ p ”. Neighbors of source and sink always forward msg even if
they are out of the ellipse.
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ROUTING PROTOCOLS WITH LOCALIZATION ERRORS
ELLIPSEAssumptions:
probability “p ” defines a sub-set of nodes which will relay msg towards destination
before deployment, all the sensors know the ellipse factor and destination position
before sending , the source includes its position (xs, ys)
when sensor “u” receives a msg, it checks whether it is inside the ellipse by the following formula:
Dsu + Dud <= l.d where l: ellipse factor, d: distance between source and sink
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ROUTING PROTOCOLS WITH LOCALIZATION ERRORS
Localization error management in ELLIPSE:
When the source is not accurately located, because it’s an important parameter to define the ellipse: all neighbors of the source have to forward msg (to relay nodes) even if they are outside the ellipse.
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ROUTING PROTOCOLS WITH LOCALIZATION ERRORS
Localization error management in ELLIPSE:
Problem: to how many hops?? If h=1 all 1-hop neighbors are relay nodes
Solution: the minimal number of hops to reach sensors close to S is the ceiling of [/r]. To avoid dropping msg: h>= [/r] +1
Problem: when the node’s position is not accurate, because it cannot determine if it is inside the ellipse it cannot determine if it is a relay node.
Solution: each potential relay node can calculate its probability to be inside the ellipse PA= AA / ²A….where AA is the intersection of the circle of A and the ellipse
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ROUTING PROTOCOLS WITH LOCALIZATION ERRORS
Summary: Managing Localization error leads to significant energy
consumption Suitable to mobile network because there’s no need to
know neighbors position
Drawbacks: Does not focus on the broadcasting strategy inside the
ellipse !!! Why choosing Ellipse as a region and not other region
form???
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SUMMARY
Protocol Category
Greedy Forwarding Geographic
GAF Geographic
SPEED QoS-based
MMSPEED MultiPath-based & QoS-based
TTDD, ALURP, EERMP, ELASTIC Geographic supporting Mobility
ELLIPSE Geographic with localization error
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