mobile data gathering with space-division multiple access in wireless sensor networks miao zhao,...

Mobile Data Gathering with Space-Division Multiple Access in Wireless Sensor Networks

Miao Zhao, Ming Ma and Yuanyuan YangDepartment of Electrical and Computer Engineering, State

University of New York

IEEE INFOCOM 2008

Outline

Introduction

SDMA Technique

MDG-SDMA Problem

Heuristic Algorithms

Performance Evaluation

Conclusions

Introduction

Recent years have witnessed a surge of interest in efficient data gathering schemes in WSNs. Routing protocol

Distributed data compression Efficient transmission schedule Hierarchical infrastructure

Mobile data gathering Data MULEs (Data collector)

Introduction

Mobile data gathering (MDG) Radically solves the non-uniformity of energy consumption

among sensors. The mobile data collector works well not only in a fully

connected network, but also in a disconnected network.

SenCar (data mule)

Sensors

Sink

Introduction

The total time of a data gathering tour mainly consists of Data uploading time Moving time

SenCar (data mule)

Sensors

Sink

Introduction

This paper improve the performance of data gathering in WSNs by considering two critical factors: The mobility of Data MULE . Space-Division Multiple Access (SDMA) technique.

SenCar (data mule)

Sensors

Sink

SDMA Technique

The SenCar is the receiver equipped with multiple antenna Sensors are the senders each having a single antenna to upload

sensing data to the SenCar.

Maximum Matching Problem

Compatible

Matched Compatible Pair

Polling Point

Sensors

Assume that the SenCar is the receiver equipped with two antennas

MDG-SDMA Problem

Maximum Matching Problem Traveling Salesman Problem (TSP)

0

Matched Compatible Pair

Polling Point

MDG-SDMA Problem

Maximum Matching Problem Traveling Salesman Problem (TSP)

0 1 2 3 4 5 6

7 8 9 10 11 12 13

14 15 16 17 18 19 20

21 22 23 24 25 26 27

28 29 30 31 32 33 34 Matched Compatible Pair

Polling Point

Compatible

Heuristic Algorithms

Maximum Compatible Pair (MCP) Algorithm

Minimum Covering Spanning Tree (MCST) Algorithm

Revenue-Based (RB) Algorithm

Heuristic Algorithms

Maximum Compatible Pair (MCP) Algorithm

Heuristic Algorithms

Maximum Compatible Pair (MCP) Algorithm

1 2

43

12

3

45 6

7

8

9

10

Matched Compatible Pair

Polling Point

Selected Polling Point

Sensors

Heuristic Algorithms

Minimum Covering Spanning Tree (MCST) Algorithm

Heuristic Algorithms

Minimum Covering Spanning Tree (MCST) Algorithm

1 2

43

12

3

45 6

7

8

9

10

τ : the average cost of a polling point d : the distance between two adjacent polling points

τ1(P1)=0/4=0τ1(P2)= d/4τ1(P3)= d/4τ1(P4)=√2d/5.

τ2(P2)= d/2τ2(P3)= d/3τ2(P4)=√2d/5.

τ3(P2)= ∞τ3(P3)= d

d

dd2

d

i

ii n

d)(P

Heuristic Algorithms

Revenue-Based (RB) Algorithm

Heuristic Algorithms

Revenue-Based (RB) Algorithm

1 2

43

12

3

45 6

7

8

9

10

R(i)= −αω(i)+βτ(i) ,whereαandβare positive coefficients,

ω(i) is the maximum matching among the uncovered sensors in the neighbor set of Piτ(i) is the average cost of Pi as defined in the MCST algorithm.

ω1(P1)=2ω1(P2)=2ω1(P3)=1ω1(P4)=2

τ1(P1)=0τ1(P2)= d/4τ1(P3)= d/4τ1(P4)=√2d/5.

ω2(P2)=1ω2(P3)=1ω2(P4)=2

τ2(P2)= d/2τ2(P3)= d/τ2(P4)=√2d/5.

α=1 ,β=1

Performance Evaluation

There are a total of 20 sensors scattered over the 60m×60m square area 25 polling points are located at the intersections of grids and each one

is 15m apart from its adjacent neighbors in horizontal and vertical directions.

The authors set the radius of the coverage area of each polling point to 30m, which is also the transmission range of each sensor.

Performance Evaluation

Performance Evaluation

5

Performance Evaluation

Performance comparison among different MDG algorithms.

Performance Evaluation

Performance Evaluation

Conclusions

The authors have introduced a joint design of mobility and SDMA technique to data gathering in WSNs.

The authors formulated MDG-SDMA Problem.

The authors proposed three heuristic algorithms to provide practically good solutions to the problem.

Thanks for your attention!