Investigation on Mutual Contention Bandwidth Request Mechanisms in Two-Hop Relay Network with ITU-R Path Loss Models

Table 2

Simulation parameters.

Parameters	Details
Multiple access	OFDMA
Duplexing	TDD
Frequency (GHz)	5.8
Frame duration (ms)	5
Symbol duration (us)	100.8
Number of subcarriers	2048
Number of subchannels	70
Usage mode	PUSC
Uplink subframe size (symbols)	12
Number of BS/RS/MS	1/3/75
BS coverage (km)	5
RS coverage (m)	300
Maximum hops	2
Pathloss model	Suburban fixed, vehicular, or outdoor to indoor and pedestrian
Multipath channel model	ITU Channel A
Ranging power step (mW)	0.25
Bandwidth request backoff start	2
Bandwidth request backoff end	4
Reservation timeout (contention)	16
Request retries	16
Application	Best effort (FTP and HTTP)
Efficiency mode	Physical layer enabled
Simulation platform	OPNET 14.5