Performance Optimization of Priority Assisted CSMA/CA Mechanism of 802.15.6 under Saturation Regime.
Due to the recent development in the field of Wireless Sensor Networks (WSNs), the Wireless Body Area Networks (WBANs) have become a major area of interest for the developers and researchers. Human body exhibits postural mobility due to which distance variation occurs and the status of connections amongst sensors change time to time. One of the major requirements of WBAN is to prolong the network lifetime without compromising on other performance measures, i.e., delay, throughput and bandwidth efficiency. Node prioritization is one of the possible solutions to obtain optimum performance in WBAN. IEEE 802.15.6 CSMA/CA standard splits the nodes with different user priorities based on Contention Window (CW) size. Smaller CW size is assigned to higher priority nodes. This standard helps to reduce delay, however, it is not energy efficient. In this paper, we propose a hybrid node prioritization scheme based on IEEE 802.15.6 CSMA/CA to reduce energy consumption and maximize network lifetime. In this scheme, optimum performance is achieved by node prioritization based on CW size as well as power in respective user priority. Our proposed scheme reduces the average back off time for channel access due to CW based prioritization. Additionally, power based prioritization for a respective user priority helps to minimize required number of retransmissions. Furthermore, we also compare our scheme with IEEE 802.15.6 CSMA/CA standard (CW assisted node prioritization) and power assisted node prioritization under postural mobility in WBAN. Mathematical expressions are derived to determine the accurate analytical model for throughput, delay, bandwidth efficiency, energy consumption and life time for each node prioritization scheme. With the intention of analytical model validation, we have performed the simulations in OMNET++/MIXIM framework. Analytical and simulation results show that our proposed hybrid node prioritization scheme outperforms other node prioritization schemes in terms of average network delay, average throughput, average bandwidth efficiency and network lifetime.
COMSATS Institute of Information Technology, Islamabad 44000, Pakistan. mustafa.shakir@comsats.edu.pk.
Mustafa
M
Shakir
COMSATS Institute of Information Technology, Islamabad 44000, Pakistan. obaid.rehman@comsats.edu.pk.
Obaid Ur
OU
Rehman
COMSATS Institute of Information Technology, Islamabad 44000, Pakistan. muddasir1994@yahoo.com.
Mudassir
M
Rahim
Biomedical Technology Department, College of Applied Medical Sciences, King Saud University, Riyadh 11633, Saudi Arabia. nabil@ksu.edu.sa.
Nabil
N
Alrajeh
CIS, Higher Colleges of Technology, Fujairah, P.O. Box 4114, United Arab Emirates. zahoor.khan@dal.ca.|Department of Engineering Maths and Internetworking, Dalhousie University, Halifax, NS B3J 4R2, Canada. zahoor.khan@dal.ca.
Zahoor Ali
ZA
Khan
COMSATS Institute of Information Technology, Islamabad 44000, Pakistan. mahmoodashraf@comsats.edu.pk.
Mahmood Ashraf
MA
Khan
COMSATS Institute of Information Technology, Islamabad 44000, Pakistan. ianiaz@comsats.edu.pk.
Iftikhar Azim
IA
Niaz
COMSATS Institute of Information Technology, Islamabad 44000, Pakistan. nadeemjavaid@comsats.edu.pk.
Nadeem
N
Javaid
CSMA/CA; IEEE 802.15.6; WBAN; energy efficiency; network lifetime; node prioritization