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