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Narrowband Internet of Things (NB-IoT) is a cellular-based technology standardized by the Third Generation Partnership Project (3GPP) in Release-13 with the primary focus to support low-power, low-data rate, and delay-tolerant applications. The main contributions of this article are: (a) we describe the architecture of NB-IoT and its evolution in further 3GPP Releases and (b) we develop a semi-Markov based energy-saving model for the NB-IoT device. Different from the other existing approaches which focus on the optimization of power consumption of the NB-IoT device, we propose the addition of a novel Auxiliary State to the conventional NB-IoT Discontinuous Reception (DRX) mechanism. This state facilitates the reduction in energy consumption of the NB-IoT device, especially in case of small data transmission. The performance of the proposed scheme is analyzed in terms of power saving factor and average delay experienced by the device for varying eDRX timer, PSM timer, DRX cycle duration, and DRX active duration values. The proposed model is also evaluated for different arrival rates of the data packets and thresholds on the number of data packets.In this study, we claim that the newly introduced Auxiliary State improves the power saving of the NB-IoT user on the arrival of very small data packets. Numerical results show that the power saving factor increases up to 97.1% and 98.25% by varying the eDRX timer and PSM timer, respectively.

Vehicular communication plays a crucial role in improving road safety and maintaining traffic efficiency through the exchange of safety messages. Besides road safety, it can also be used to support other nonsafety features such as infotainment services, traffic management, parking assistance, and so on. In this article, we explore a hybrid long term evolution vehicle‐to‐everything architecture where we use both vehicle‐to‐infrastructure (V2I) and vehicle‐to‐vehicle (V2V) communication to simultaneously provide high throughput for infotainment services and maintain high reliability and low transmission delay for the safety messages. To this end, we propose V2I and V2V resource allocation algorithms which support a strict allocation priority for the safety messages over the nonsafety messages. We evaluate the performance of the proposed algorithms by extensive simulations using OMNeT++, INET, and SimuLTE softwares and analyze the simulation data using MATLAB software. The simulation results indicate that, as compared with using only V2I communication, the proposed algorithms decrease the end‐to‐end delay (∼23%, on average) of the safety messages with little degradation (< 10%, on average) in throughput of the background traffic. We compare our proposed algorithms with the existing algorithms and find that the proposed algorithms show a performance gain of 36.5% and 45% in terms of end‐to‐end latency and packet reception ratio, respectively.