1. Edinburgh Napier University
An Energy-Efficiency Routing Scheme Based on Clusters with a Mobile Sink for WSNs
Edinburgh Napier University
Xiaodong Liu and Qi Liu
Conference Date: June 18

2. Background 01
Routing Scheme 02
CONTENTS
Results 03
Conclusion 04

3. Background WSN Part one: Overview
WSN: large-scale, self-organization and multi-hops network
Sensor nodes: small and cheap
Application: military, healthcare, environmental, traffic and civilian
Challenge: energy-efficiency, network lifetime, rate of packets delivered

4. The optimal routing is determined through our scheme
Background
WSN
Part two: Routing Introduction 01
traditional methods
single hop; serious energy consumption 02
layered approaches
multi-hops; the network life; energy-efficiency
sink: a significant breakthrough
Our scheme: energy-efficiency routing algorithm, multi-hops, Random deployment.
The optimal routing is determined through our scheme

5. Routing Scheme System Model Part one: Basic Assumption
1. sensor nodes: randomly deployed in a regular rectangle network
2. each node: the unique identifier
3. the sink and the BS: energy consumption can be ignored
4. the relay node and major node: unique
5. first round: the energy of the whole nodes is enough

6. Routing Scheme System Model Part two: Network Model
G=<V, K>: randomly deployed WSN
V represents the each node and K represents the weight between two adjacent nodes
k(i, j) represent the distance between the node i and its adjacent node j
Network partition
The whole network is divided into several regions on the basis of the regulation

7. Routing Scheme System Model Part three: Energy Model
the first radio energy model

8. Routing Scheme Scheme Design Part one: Network Partition
the number of the regions is determined by the 5% of the sensor nodes, formula is as

9. Routing Scheme Scheme Design Part two: Mobile Strategy of the Sink
1. The sink moves at the fixed speed along the predetermined routing in the deployed sensor networks.
2. The sink will sojourn at position near the relay node and collects the data from the source after the relay node is determined.
Part three: Selection of Relay Node
first stage: the nodes of the distance inside r0 are selected between the sink and its adjacent nodes with the RSSI
second stage: the maximum residual energy node is selected as the relay node among these nodes according to the first stage

10. Routing Scheme Scheme Design Part four: Selection of Major Node
Selection of major node is on the basics of the residual energy and the identifier of node
First, the node which near to the center of the region can be regarded as the major node;
Second, it needs to compare the residual energy and the identifier with neighbors for selecting the most suitable major node.
If the residual energy of neighbor nodes is less than the node, then it continues to compare with other adjacent nodes until all the nodes are involved in the comparison

11. Routing Scheme Scheme Design Part five: Routing Determining
1. calculating the distance between the source and neighbor node to determine which node is the nearest to the source according to the signal strength of RSSI, then adding the identifier of the node that is nearest to the source into the routing table;
2. according to 1, the node also calculate the distance between the node and adjacent nodes to judge which node is closest to the node, then adding the identifier of new node in to the routing table;
3. considering the new node according to 2, the node sends the packet to the new node which concludes the latest hop count, the distance and the routing table;
4. repeating 2 and 3, until taking the all node on the direction of the relay node into account.

12. Routing Scheme Scheme Design Part six: Data Transmission
1. when the region which the sink sojourns at and the region that the source located is the same, The aggregated data is transmitted from the major node to the relay node along the routing, finally the data is transmitted to the sink by the relay node;
2. when the region which the sink sojourns at and the region that the source located is not the same, but the two regions are adjacent. There are two kinds ways of next data transmission which are:
-----with major node: the major node directly transmits the aggregated data to the major node of the region which the relay node locates in.
-----without major node: the relay node directly collects the data from the major node.

13. Routing Scheme Scheme Design Part six: Data Transmission
3. when the region which the sink sojourns at and the region that the source located is not the same, but the two regions are not adjacent.
-----First, the major node of these regions collects the data from the source and aggregates them together for the each region.
-----Then the aggregated data is transmitted from the first major node to the major node of the last hop region which the relay node located.
-----Finally, the sink collects the aggregated data according to 2.

14. Results Testing Environment
the number of sensor nodes is set to 500, and other parameters is shown on the Table

15. Results
Performance Evaluation
Part one: Comparison of Residual Energy

16. Results Performance Evaluation
Part two: Comparison of Packet Delivered successfully

17. Conclusion 1
Compared with other routing schemes, our proposed scheme has the less energy consumption.
The energy-efficiency routing scheme based on clusters with a mobile sink for WSNs is proposed, which consist of six parts. 2
But there are still some shortcomings:
it is not enough for conducting the evaluation in an ideal environment where the several factors and many parameters are ignored .
In the future, we will try our best to take these factors into account for the further research.

18. THANKS