ENERGY AWARE FAULT TOLERANT DATA DISSEMINATION IN SENSOR NETWORKS

By:

PRAJWAL PANCHMAHALKAR

NISHANTH REDDY KOMMIDI

Wireless Sensor Network (WSN) consists of spatially distributed autonomous sensors which cooperatively pass their data through the network to a main location

This work is motivated by SPMS (Shortest Path Minded SPIN) protocol

INTRODUCTION

Although SPMS was successful in achieving better latency and low power consumption compared to the SPIN protocol, it lacks in the following areas:

Energy at the nodes is not considered: Relay nodes have additional overhead as they have to relay the

data between source and destination If a node in shortest path fails and the SCONE is not in the

range of the node sending the request then there is no solution provided.◦ But the aim of SPMS was fault tolerance !

PROBLEM

We assume that the communication overhead is higher than the storage overhead

ASSUMPTIONS

We discuss the failure cases of SPMS to provide a solution for the SPMS protocol

Here each node has the information of its neighbors zone along with its own zone

A Node also maintains the routing table to each of its neighbors. Motivated from SPIN and SPMS protocols

DESIGN of Energy Aware SPMS

DESIGN OVERVIEW

Destination

Cost Via

B 1 -

C 1 -

D 2 C

A B

C

D

E

F

E

F

A

Routing Table of Neighbor B

Routing Table of A

DESIGN IMPLEMENTATION

Relay nodes (we call smart relay) are aware of its own residual energy and the energy it can spend the current communication

Smart relays, when they get a REQ from a destination node estimates the cost in relaying the data and calculates the Energy,

Er = Ep – (Erec + Et)

Where, Er = Energy expected to remain after relaying

Ep = Energy present at current time

Erec = Energy spent in receiving the data from the source

Et = Energy spent in transmitting the data to the destination

DESIGN IMPLEMENTATION

Relay nodes then set a 3 energy bits in it’s REQ while sending to the secondary relay node. We call it En-bit

This bit is a product which has the information of how much battery energy will be left in the relay node after the relay of data along with the cost.

The secondary relay node based on the En-bit will go into a waiting state which will be inversely proportional to En-bit

Trw α 1/En –bit◦ Trw - Waiting time for the smart relay node.

Meanwhile the nodes present in the zone of the relay node which over hears the REQ also analyze the En-bit and calculate their own En-bit if they have both the destination and secondary relay node in their routing table and sends to secondary relay node

ENERGY AWARE FAILURE FREE CASE - Scenario

destination

source

Relay nodes

Nodes in zone of relay nodes

A

B C

D

E

F

ENERGY AWARE FAILURE FREE CASE – Data transfer

destination

source

Relay nodes

Nodes in zone of relay nodes

REQ

A

B C

D

E

F

Node C calculates the energy it will be left with after the relaying

ENERGY AWARE FAILURE FREE CASE – Data transfer

destination

source

Relay nodes

Nodes in zone of relay nodes

A

B C

D

E

F

REQ

overhear

overhear

REQ – Contains En-Bit

ENERGY AWARE FAILURE FREE CASE – Data transfer

destination

source

Relay nodes

Nodes in zone of relay nodes

A

B C

D

E

F

Trw Are B and D in my zone ?Calculate En-bit and is it higher than C ?

ENERGY AWARE FAILURE FREE CASE – Data transfer

destination

source

Relay nodes

Nodes in zone of relay nodes

A

B C

D

E

F

F – has High En-bit

REQ REQ

ENERGY AWARE FAILURE FREE CASE – Data transfer

destination

source

Relay nodes

Nodes in zone of relay nodes

A

B C

D

E

F

F – has High En-bit

ADVDAT

SNIP

DAT

ENERGY AWARE NODE FAILURE CASE - Scenario

destination

source

Relay nodes

Nodes in zone of relay nodes

A

B C

D

E

F

Works similar to energy aware case where nodes in the zone of C – E and

F take up