In-band full-duplex medium access control design for heterogeneous wireless LAN
Alim et al. EURASIP Journal on Wireless Communications and
Networking
In-band full-duplex medium access control design for heterogeneous wireless LAN
Md. Abdul Alim 0 1
Makoto Kobayashi 1
Shunsuke Saruwatari 1
Takashi Watanabe 1
0 ECE Discipline, Khulna University , Khulna , Bangladesh
1 Department of Information Networking, Graduate School of Information Science and Technology, Osaka University , Osaka , Japan
Full-duplex (FD) wireless communication is evolving into a practical technique, and many studies are being conducting in this area, especially regarding the physical layer. However, to exploit FD benefit successfully, efficient medium access control (MAC) protocols are crucial as well as physical layer advances. Numerous FD-MAC protocols have been proposed, but these MAC protocols cannot address all the issues encountered in this area. In addition, many half-duplex (HD) capable devices are present in existing wireless local area networks (WLANs), so there is an urgent need to integrate FD clients and HD clients in the same WLAN. We refer to this type of WLAN as a heterogeneous WLAN (Het-WLAN). In this paper, we propose an FD-MAC for Het-WLAN, which considers all possible types of FD transmissions. Our proposed FD-MAC protocol suppresses inter-user interference. Simulation results demonstrated that a significant throughput gain (about 96%) could be achieved by using our proposed FD-MAC compared with traditional HD communications. Moreover, our proposed MAC obtained better performance (average throughput gain of about 11%) compared with another existing FD-MAC design. In addition, probability analysis suggested that the total probability of FD transmissions increased rapidly as the WLAN approached saturation conditions.
Full-duplex; MAC protocol; Het-WLAN; FD-MAC
1 Introduction
In general, traditional radio transceivers cannot
transmit and receive simultaneously using the same frequency
band because of self-interference at the receiver end.
However, recent technological advances in antenna design
and radio frequency interference cancellation techniques
can reduce self-interference by up to 110 dB [1]. Similar
studies have also been conducted regarding the physical
layer by [2–4]. The latest technologies for self-interference
cancellation allow us to transmit and receive signals
simultaneously using the same frequency, which is known
as in-band full-duplex (IBFD) communication [5].
However, a suitable medium access control (MAC) is crucial
to exploit the full advantages of IBFD technology in
wireless local area networks (WLANs) because the current
IEEE standard MAC protocols do not support IBFD
communications. IBFD is one of the techniques with the
greatest potential for supporting the huge traffic demands
in the near future, and researchers are attracted to IBFD
because it can increase the spectral efficiency without
requiring any additional frequency resources [5]. IBFD
can also double the ergodic capacity of a multiple-input
multiple-output system [1, 3].
IBFD wireless communication can be categorized as
bidirectional FD (BFD), three node FD (TNFD), or relay
FD (RFD) [5, 6]. BFD and TNFD are illustrated in Fig. 1.
Two nodes comprising the primary transmitter (PT) and
primary receiver (PR) transmit to and receive from each
other simultaneously (Fig. 1a) in BFD. TNFD can be
described as destination-based TNFD or source-based
TNFD. In destination-based TNFD, PT transmits a signal
to PR and PR also transmits a signal to another secondary
receiver (SR) while receiving data from PT (Fig. 1b). In
this case, PR also acts as a secondary transmitter (ST). In
source-based TNFD, PT transmits data to PR and ST also
transmits data to PT (Fig. 1c). In this case, PT also acts as
a SR. However, in RFD, a user terminal sends data to the
destination using a relaying node [5]. In this study, we
consider three modes of transmission, i.e., half-duplex (HD),
BFD, and TNFD.
© The Author(s). 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
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Fig. 1 a BFD, b destination-based TNFD, and c source-based TNFD
All of the user terminals or nodes in existing WLANs
are traditional HD capable. Therefore, it is not possible
to replace all of these HD nodes (HDNs) with FD nodes
(FDNs) overnight, so it is necessary to incorporate FDNs
in existing WLANs in a manner that allows HDNs and
FDNs to operate simultaneously. A WLAN that comprises
HDNs and FDNs is referred to as a heterogeneous WLAN
(Het-WLAN) because it has different types of clients or
nodes.
In this paper, we propose an FD-MAC for Het-WLAN,
which we call HFD-MAC. The basic structure of
HetWLAN is shown in Fig. 2, (...truncated)