A LOW LATENCY MAC PROTOCOL WITH REDUCED HANDSHAKING FOR PROVISIONING SPATIAL FAIRNESS IN UNDERWATER SENSOR
NETWORK
By
Md. Abir Hossain
MASTER OF SCIENCE IN
INFORMATION AND COMMUNICATION TECHNOLOGY
INSTITUTE OF INFORMATION AND COMMUNICATION TECHNOLOGY BANGLADESH UNIVERSITY OF ENGINEERING AND TECHNOLOGY
Dedication
THIS THESIS IS DEDICATED TO
MY PARENTS AND
MY BELOVED WIFE
Contents
Declaration ii
Dedication iii
List of Tables vii
List of Figures ix
List of Abbreviation x
List of symbols xi
Acknowledgment xii
Abstract xiii
1 Introduction 1
1.1 Spatial-Temporal Uncertainty . . . .. . . 1
1.2 Spatial Unfairness . . . .. . . . 3
1.3 Motivation . . . .. . . .. . . . 3
1.3 Research Objectives . . . 4
1.4 Outline of Methodology . . . 4
1.5 Organization of Thesis . . . .. . . .. . . . 5
1.6 Summary . . . 6
2 Basics and Literature Review 7 2.1 Typical Underwater Wireless Sensor Node. . . 7
2.2 Underwater MAC protocols Classification . . . 8
2.3 General Characteristics of Underwater Wireless Sensor Network . . . 9
2.4 Underwater Wireless Sensor Network Architecture. . . . . 10
2.5 Underwater Sensing Applications. . . 11
2.6 Research Challenges in Underwater Wireless Sensor Network. . . 12
2.7 MAC Protocol Responsibility . . . ………. 14
2.8 Underwater wireless Sensor Network MAC protocols . . . 14
2.8.1 Spatially Fair MAC(SF-MAC) Protocol . . . 14
2.8.2 RET-MAC Protocol . . . 16
2.8.3 Receiver Oriented Sleep Scheduling(ROSS) MAC Protocol .. . . 17
2.8.4 Location Aware Routing Protocol(LARP) . . . 19
2.8.5 Multi-Hop-Enabled Energy-E_cient MAC Protocol . . . 20
2.8.6 Multi-Receiver(MR-MAC) MAC Protocol . . . 23
2.8.6.1 Channel Reservation Phase . . . 23
2.8.6.2 Data Transmission Phase . . . 24
2.9 Summary . . . 25
3 Proposed MAC Protocol Design 3.1 Introduction . . . 26
3.2 Major Observation of Existing SF-MAC protocol . . . 26
3.2.1 Closer Nodes to Receiver are Deprived . . . 26
3.2.2 RTS collision in RTS contention Period . . . .. . . 28
3.2.3 Collision scenario of SF-MAC . . . .. . . .. . . . 28
3.2.3.1 Collision scenario due to data exchange within 2Dmax timing range in SF-MAC . . . .. . . .. . . 28
3.2.3.2 Collision scenario due to short backoff by intermediate node in SF-MAC . . . 29
3.2.3.3 Collision scenario with the ACK packet in SF-MAC . . . 30
3.3 Proposed MAC Protocol Design . . . 31
3.3.1 RTS Collision Avoidance Mechanism . . . 32
3.3.2 Incoming RTS Traffic Partition . . . 34
3.3.3 Propagation Delay Utilization Methodology . . . 35
3.3.4 Data Collision Avoidance Mechanism . . . 35
3.3.5 Final Aggregated MAC Protocol Timing Diagram . . . 37
3.3.6 Operational Flowchart . . . 40
3.4 Summary . . . 40
4 Simulation Results 41
4.1 Introduction . . . 41
4.2 Proposed Protocol Implemented in OMNeT++ . . . 41
4.2.1 Simulated Network in OMNeT++ . . . 41
4.2.2 Simulation Parameters in OMNeT++ . . . 42
4.3 Simulation Results . . . 42
4.3.1 Average RTS collision . . . 43
4.3.1.1 Average RTS Collision with Varying Number of Nodes . . . . 43
4.3.1.2 Average RTS Collision with Varying Sensing Range . . . 44
4.3.2 Success Rate of Sending CTS . . . 45
4.3.2.1 Success Rate of Sending CTS with Varying Sensor Nodes . . . 45
4.3.2.2 Success Rate of Sending CTS with Varying Sensing Range . . . 46
4.3.3 Latency . . . 47
4.3.3.1 Average Latency Per Packet with varying Number of Nodes 47 4.3.3.2 Average Latency Per Packet with varying Sensing Range of Nodes 48 4.3.3.3 Average Latency Per Packet with varying Inter-Arrival Time of Node 49 4.3.4 Handshaking cycle . . . 50
4.3.4.1 Total Number of Control Packet with Varying Number of Nodes 50 4.3.4.2 Total Number of Control Packet with Varying Sensing range of Nodes 52 4.3.4.3 Total Number of Control Packet with Varying Inter-Arrival Time of Nodes 53 4.3.5 Fairness Index . . . 54
4.3.5.1 Fairness Analysis with Varying Number of Nodes. . . 54
4.3.5.2 Fairness Analysis with Varying Sensing Range of Nodes . . . 55
4.3.5.3 Fairness Analysis with Varying Inter-Arrival Time of Nodes 56 4.3.6 Throughput . . . 57
4.3.6.1 Average Data Packet Receive with Varying Number of
Nodes 58
4.3.6.2 Average Data Packet Receive with Varying Sensing Range 59
4.3.6.3 Normalized Throughput with varying Number of Nodes 59 4.3.6.4 Normalized Throughput with Varying Sensing Range 60 4.4 Summary . . . 61
5 Conclusion and Future Work 62
5.1 Conclusion . . . 62 5.2 Future Work . . . 63 .
List of Tables
4.1 Simulation parameters in OMNeT++ . . . 43
List of Figures
1.1 Transmit at the same time but no collision at receiving end. . . 1
1.2 Transmit at different time but collide at receiver. . . 2
2.1 Typical Underwater wireless sensor node . . . 8
2.2 Underwater MAC protocols classification . . . 9
2.3 Typical Underwater wireless sensor network architecture . . . 11
2.4 SF-MAC protocol timing diagram . . . 15
2.5 RET-MAC protocol timing diagram . . . 17
2.6 ROSS nodes start time calculation . . . .. . . 18
2.7 Leaf node to Base station data transfer procedure . . . 18
2.8 Node S broadcasts \Destination Location" request . . . 19
2.9 Node A replies to Node S . . . 20 2.10 Network topology in MHEE protocol . . . 21
2.11 Medium access control (MAC) mechanism of the proposed protocol. . . 22
2.12 Timing diagram of MR-MAC protocol. . . 23
3.1 Closer nodes to receiver are deprived . . . 27
3.2 RTS collision in RTS contention Period . . . 27
3.3 Node C's data collide with terminal node A's RTS within 2Dmax timing range . . . 29
3.4 Node A's Data packet collide due to short back o_ of node C . . . 30
3.5 Receiver R's ACK packet collide with intermediate node B's RTS . . . 31
3.6 Proposed MAC protocol network topology . . . 31
3.7 Operational flowchart of RTS collision avoidance algorithm . . . 33
3.8 Incoming RTS traffic partition based on propagation delay . . . . . 34
3.9 Propagation delay utilization methodology . . . ……… 35
3.10 Operational flowchart of data collision avoidance algorithm . . . 37
3.11 Dual data packet receives from two regions with delay difference . . . 38
3.12 Proposed-MAC overview . . . 38
3.13 Operational flowchart of the Proposed MAC protocol . . . .. . . 39
4.1 Simulated Network in OMNeT++ . . . 42
4.2 Average RTS collision rate with varying number of nodes with simulation time 100s and packet length 512B with link rate 8kb/s. . . 44
4.3 Average RTS collision rate with varying sensing range with simulation time 100s and packet length 512B with link rate 8kb/s. . . 45
4.4 Success rate of CTS comparison with varying number of nodes . . . 46
4.5 Success rate of CTS comparison with varying transmission range of nodes 47 4.6 Average latency per packet with varying number of nodes . . . ………. 48 4.7 Average latency per packet with varying Sensing range of nodes . . . 49
4.8 Average latency per packet with varying Inter-Arrival Time of nodes 50 4.9 Total control packet required to transmit per packet with varying number of nodes 51 4.10 Total control packet required to transmit per packet with varying sensing range of nodes 52 4.11 Total control packet required to transmit per Unit Data packet with varying Inter-Arrival Time of nodes . . . 53
4.12 Fairness index with Varying number of nodes . . . 55
4.13 Fairness index with varying sensing range of nodes . . . 56
4.14 Fairness index with Varying inter-arrival time of nodes . . . 57
4.15 Average data packet receives with varying number of nodes with simulation time 100s and packet length 512B with link rate 8kb/s. . . 58
4.16 Average data packet receives with varying transmission range of nodes with simulation time 100s and packet length 512B with link rate 8kb/s. 59 4.17 Normalize throughput comparison with varying number of nodes . . . 60
4.18 Normalize throughput comparison varying sensing range of nodes. . 61
List of Abbreviations
UASN Underwater Acoustic Sensor Network
WSN Wireless Sensor Network
AUVs Autonomous Underwater Vehicles
FCFS First Come First Serve
MAC Medium Access Control
MHEE Multi-Hop-Enabled Energy-E_cient
SF-MAC Spatially Fair Medium Access Control
RET-MAC Response to the Earliest Transmitter Medium Access Control RTS CP Request to Send Contention Period
ROSS Receiver Oriented Sleep Scheduling
TDMA Time Division Multiple Access
MR-MAC Multi-Receiver Medium Access Control
ATR Ask-To-Receive packet
TNI Target Node Information
MSP Main Schedule Packet
SP Schedule Packet
DTS Distributed Tactical Surveillance
IDS Intrusion Detection System
RSSI Received Signal Strength Indicator
ISI Inter-Symbol Interference
WSN Wireless Sensor Network
ACK Acknowledgement
RTS Request To Send
CTS Clear To Send
LARP Location Aware Routing Protocol
NED Network Description Language
List of symbols
ts(m) Start time of node m ts(e) Start time of node set e
Xe(m) Serial number of m in the receiving sequence of e
C(m) The number of children of m
Le(m) Link delay from m to e
Tp Time needed to send/receive a data packet
T TDMA slot time for ROSS protocol
Dmax Maximum propagation delay
Nodepd[max] Maximum propagation delay among selected nodes
Pdelay[node] Node's self-propagation delay to receiver
CC[node] Contention count for a node Backoff[node] Backoff of a sensor node
A PD Average propagation delay
Pd2 Propagation delay of terminal nodes Pd1 Propagation delay of closer region nodes
M Size of data packet
t Time to transfer the packets in seconds
R Link rate in kbps
N:T Normalized Throughput
Acknowledgment
I would like to express my sincere and heartiest gratitude to my honorable thesis supervisor Dr. Mohammad Shah Alam, Associate Professor, Institute of Information and Communication Technology (IICT), Bangladesh University of Engineering and Technology (BUET), Dhaka for his continuous motivation, guidance and keen encouragement which helped me throughout the time of my research work. I also express my gratitude to my classmates who helped me in different aspects of the research work.
I would like to thank all the members of the board of examiners for their precious time in understanding my work and their insightful comments. I would like to thank to all of my friends and colleagues for their cooperation. Last but not least, I am grateful to my parents and wife for their continuous support and motivation.
Abstract
Underwater acoustic sensor network (UASN) is composed of different number of sensors and moving vehicles which are distributed over a long range area to perform collective monitoring. Underwater acoustic channel, characterized by long propagation delay and low data rate, suffers from space time uncertainty causing spatial unfairness in UASN. A sender node which sends its request to send (RTS) at earlier time may not always be allowed to send its data packets earlier due to its long propagation delay. In UASN, usually a receiver node allows a sender node to transmit based on the earliest reception of its RTS packet which eventually deprives the terminal nodes with earlier transmission time, thereby creating spatial unfairness problem. In order to solve the problem, existing Medium Access Control (MAC) protocols allow the sender node which initiates its RTS packet at the earliest time. However, by allowing earliest RTS transmitter, existing MAC protocols create another kind of unfairness among the closer neighbor nodes. In this research work, a spatially fair MAC protocol is proposed in which a receiving node divides all its neighbor nodes into two groups based on average propagation delay of all of its neighbor nodes. The receiver then permits one prospective sender node from each group based on the earliest transmission time within a group. Receiver node, by employing a collision avoidance algorithm which exploits the benefit of propagation delay mapping of all its neighbor nodes, ensures that the two transmitted data packet will not collide at receiver's end. Otherwise, only a single sender node with the earliest transmission time within two groups is allowed to transmit. A simulation model based on OMNeT++ is developed to compare the performance of the proposed MAC protocol.
Simulation results show that the proposed scheme achieves better performance in terms of latency, handshaking, fairness, network throughput, average RTS collision and clear to send (CTS) success rate compared to the contemporary SF-MAC and RET-MAC protocol.
