Abstract:
The Internet of Things (IoT) is an emerging paradigm that enables many beneficial and
prospective application areas, such as smart metering, smart homes, smart industries, and smart
city architectures, to name but a few. These application areas typically comprise end nodes and
gateways that are often interconnected by low power wide area network (LPWAN) technologies,
which provide low power consumption rates to elongate the battery lifetimes of end nodes, low
IoT device development/purchasing costs, long transmission range, and increased scalability, albeit
at low data rates. However, most LPWAN technologies are often confronted with a number of
physical (PHY) layer challenges, including increased interference, spectral inefficiency, and/or low
data rates for which cognitive radio (CR), being a predominantly PHY layer solution, suffices as a
potential solution. Consequently, in this article, we survey the potentials of integrating CR in LPWAN
for IoT-based applications. First, we present and discuss a detailed list of different state-of-the-art
LPWAN technologies; we summarize the most recent LPWAN standardization bodies, alliances,
and consortia while emphasizing their disposition towards the integration of CR in LPWAN.We then
highlight the concept of CR in LPWAN via a PHY-layer front-end model and discuss the benefits of
CR-LPWAN for IoT applications. A number of research challenges and future directions are also
presented. This article aims to provide a unique and holistic overview of CR in LPWAN with the
intention of emphasizing its potential benefits.
