TY - JOUR
T1 - Spectrum Sharing for Massive Access in Ultra-Narrowband IoT Systems
AU - Hattab, Ghaith
AU - Popovski, Petar
AU - Cabric, Danijela
PY - 2021
Y1 - 2021
N2 - Ultra-narrowband (UNB) communications has become a signature feature for many emerging low-power wide-area (LPWA) networks. Specifically, using extremely narrowband signals helps the network connect more Internet-of-things (IoT) devices within a given band. It also improves robustness to interference, extending the coverage of the network. In this article, we study the coexistence capability of UNB networks and their scalability to enable massive access. To this end, we develop a stochastic geometry framework to analyze and model UNB networks on a large scale. The framework captures the unique characteristics of UNB communications, including the asynchronous time-frequency access, signal repetition, and the absence of base station (BS) association. Closed-form expressions of the transmission success probability and network connection density are presented for several UNB protocols. We further discuss multiband access for UNB networks, proposing a low-complexity protocol. Our analysis reveals several insights on the geographical diversity achieved when devices do not connect to a single BS, the optimal number of signal repetitions, and how to utilize multiple bands without increasing the complexity of BSs. Simulation results are provided to validate the analysis, and they show that UNB communications enables a single BS to connect thousands of devices even when the spectrum is shared with other networks.
AB - Ultra-narrowband (UNB) communications has become a signature feature for many emerging low-power wide-area (LPWA) networks. Specifically, using extremely narrowband signals helps the network connect more Internet-of-things (IoT) devices within a given band. It also improves robustness to interference, extending the coverage of the network. In this article, we study the coexistence capability of UNB networks and their scalability to enable massive access. To this end, we develop a stochastic geometry framework to analyze and model UNB networks on a large scale. The framework captures the unique characteristics of UNB communications, including the asynchronous time-frequency access, signal repetition, and the absence of base station (BS) association. Closed-form expressions of the transmission success probability and network connection density are presented for several UNB protocols. We further discuss multiband access for UNB networks, proposing a low-complexity protocol. Our analysis reveals several insights on the geographical diversity achieved when devices do not connect to a single BS, the optimal number of signal repetitions, and how to utilize multiple bands without increasing the complexity of BSs. Simulation results are provided to validate the analysis, and they show that UNB communications enables a single BS to connect thousands of devices even when the spectrum is shared with other networks.
KW - Internet of Things
KW - LPWA
KW - massive access
KW - spectrum sharing
KW - stochastic geometry
KW - success probability
KW - transmission capacity
KW - ultra-narrowband
UR - http://www.scopus.com/inward/record.url?scp=85090228823&partnerID=8YFLogxK
U2 - 10.1109/JSAC.2020.3018797
DO - 10.1109/JSAC.2020.3018797
M3 - Journal article
SN - 0733-8716
VL - 39
SP - 866
EP - 880
JO - I E E E Journal on Selected Areas in Communications
JF - I E E E Journal on Selected Areas in Communications
IS - 3
M1 - 9180037
ER -