Impact of access class barring in narrow band internet of things

Low-power wide-area network (LPWAN) is an important category of internet of things network topology. LPWAN connects a massive number of low-cost devices with low-power consumption and long coverage range. Narrow band internet of things (NB-IoT) is a Third Generation Partnership Project (3GPP) standard specifically designed for LPWAN. Owing to massive connectivity random access channel (RACH) of NB-IoT often gets overloaded. This potential problem needs to be addressed immediately. For controlling the RACH overload, 3GPP has introduced two access barring mechanisms in LTE, which are (i) access class barring and (ii) extended access barring (EAB). In NB-IoT only EAB mechanism has been adopted. In this study, the authors show through simulations that broadcasting of the access barring factor and barring time in system information block-2 can be used to improve the success probability and reduce the access delay of random access mechanism of NB-IoT for different traffic models.