Post on 11-Jan-2016
transcript
CuMPE:
CLUSTER-MANAGEMENT AND POWER EFFICIENT PROTOCOL FOR WIRELESS SE
NSOR NETWORKS
ITRE’05Information Technology: Research and Education
Shen Ben Ho and Xiao Su
Department of Computer Engineering, San Jose State University, San Jose, CA 951
92
Outline
Introduction Related work CuMPE Protocol
ROUTING IN CuMPE MAC SCHEDULING IN CuMPE
Simulation Conclusions
Introduction – background
Important issues in data gathering Low power consumption
Limited power supply Low transmission delay
Large number of sensor nodes
Introduction – motivation
Routing and MAC protocols should be power efficient Should organize nodes in a way that
the Message transmission delay is small
Related work - HIT
Hybrid Indirect Transmissions (HIT) for Data Gathering in Wireless Micro Sensor Networks with Biomedical Applications (CCW 2003)
Related work - HIT
Closest node to i d(u, H) < d(i, H) d(i, u) < d(i, H).
Parallel transmissions The drawback
distance advertisement messages cover the entire cluster
CuMPE - overview
Cluster head election Route set-up TDMA scheduling Data transfer
ROUTING IN CuMPE Cluster head election Route set-up
find routing trees with minimum transmission cost
reduce the energy used
Cluster head election
Depending on requirements from application
Four ways can be used to select cluster head: Random Node ID Residential energy Connectivity or geography location
Route set-up
Finds the path to the cluster head with minimum cost Phase one: Cluster Head
Advertisement Phase two: Path setup
Cluster Head Advertisement
Advertisement (fixed signal strength) Type: DISCOVERY Cost: 0
Any node receiving this packet knows the ID of cluster head the signal strength of the packet.
CH
a
db
fh
g
e
c
Path setup Updated message (fixed signal strength)
Type: DISCOVERY Cost: (cost to cluster head)
Any node receiving the updated information packet knows node ID of the sender (probably upstream node) cost from the sender to the cluster head cost to the sender.
CH
a
db
fh
g
e
c
Path setup
The node receives update message The New cost Compares current cost
High : ignore Low : the sender become the new upstream node
CH
a
db
fh
g
e
c
Cost(c,b)+Cost(b,CH)<Cost(c,CH)
Cost(d,b)+Cost(b,CH)>Cost(d,CH)
Path setup
CH
a
db
fh
g
e
c
MAC SCHEDULING IN CuMPE Use TDMA to schedule nodes for
transmission Reduce overall delays of message
transmission Blocking Nodes Critical Path
Blocking Nodes
G blocks nodes H to L
Node X block node Y : d( X, uX) > d( X, uY)
Critical Path Critical path : the path that involves the longest
delay to transmit messages from leaf nodes to the root.
the delay depends on the height of the path the number of downstream nodes along the path.
TDMA scheduling
There are four phases in this step Upstream node notice Sending downstream node list and
downstream-blocking node list Schedule setup Schedule broadcast
Upstream Node Notice
The message Type: UpStream Upstream: ID of the upstream neighbor
Any node that hears this message will put the sender downstream node list (its own ID) downstream-blocking node list.
A
C
D
B
F
H
G
E
Downstream node list: D
Downstream node list: H GDownstream-blocking node list :D
Sending Downstream Node List and Downstream-Blocking Node List
A
C
D
B
F
H
G
E
Schedule setup
The protocol assigns the time slot reverselyi.e., assigns the last time slot first
The protocol checks if any blocking node is assigned to that time slot.
A
C B
Schedule setup
Nodes with an asterisk on right are in the queue.
C B
B E F
Schedule setup
Node D blocks the downstream nodes of C and E (i.e., nodes E, F, G, and H),
The algorithm shifts node F to the next free slot
B E F
F
E F D
Schedule setup
Choose to delay the blocked node results in a shorter overall delay
Slot 1
Slot 2
Slot 3
Slot 4
Slot 5
Slot 6
Slot7
B A
H I J K L
G C D E F
Slot 1
Slot 2
Slot 3
Slot 4
Slot 5
Slot 6
Slot7 Slot8
Slot9
Slot10
Slot11
B A
H I J K L
G C D E F
Schedule setup
Finished TDMA scheduling all the nodes in the queue are leaf nodes have no downstream nodes
E F D
F D G H
G
Schedule Broadcast The cluster head sends the TDMA schedule
information to the cluster members. The message has the following fields
Type: Timeslot Time slot: the time slot assigned.
A
C
D
B
F
H
G
E1
2
2
34
45
Simulation
Network: diameter of 1000 meters 100 nodes Cluster heads : 5% node Initial energy of node : 25 joules Packet size :100 bits The route is recomputed every 100
rounds of data gathering
Simulation- Lifetime
Simulation- Average Delay
Conclusion
CuMPE consists of a routing and a TDMA scheduling algorithm has longer life time has shorter transmission delay