Analytical Modeling and Experimental Validation of NB-IoT Device Energy Consumption

The recent standardization of 3GPP Narrowband Internet of Things (NB-IoT) paves the way to support low-power wide-area (LPWA) use cases in cellular networks. NB-IoT design goals are extended coverage, low power and low cost devices, and massive connections. As a new radio access technology, it is necessary to analyze the possibilities NB-IoT provides to support different traffic and coverage needs. In this paper, we propose and validate an NB-IoT energy consumption model. The analytical model is based on a Markov chain. For the validation, an experimental setup is used to measure the energy consumption of two commercial NB-IoT user equipments (UEs) connected to a base station emulator. The evaluation is done considering three test cases. The comparison of the model and measurements is done in terms of the estimated battery lifetime and the latency needed to finish the control plane procedure. The conducted evaluation shows the analytical model performs well, obtaining a maximum relative error of the battery lifetime estimation between the model and the measurements of 21% for an assumed interarrival time (IAT) of 6 min.This work was supported in part by the Spanish Ministry of Economy and Competitiveness and the European Regional Development Fund under Project TEC2016-76795-C6-4-R and in part by the H2020 European Project TRIANGLE under Grant 688712

A Modelling and Experimental Framework for Battery Lifetime Estimation in NB-IoT and LTE-M

To enable large-scale Internet of Things (IoT) deployment, Low-power wide-area networking (LPWAN) has attracted a lot of research attention with the design objectives of low-power consumption, wide-area coverage, and low cost. In particular, long battery lifetime is central to these technologies since many of the IoT devices will be deployed in hard-toaccess locations. Prediction of the battery lifetime depends on the accurate modelling of power consumption. This paper presents detailed power consumption models for two cellular IoT technologies: Narrowband Internet of Things (NB-IoT) and Long Term Evolution for Machines (LTE-M). A comprehensive power consumption model based on User Equipment (UE) states and procedures for device battery lifetime estimation is presented. An IoT device power measurement testbed has been setup and the proposed model has been validated via measurements with different coverage scenarios and traffic configurations, achieving the modelling inaccuracy within 5%. The resulting estimated battery lifetime is promising, showing that the 10-year battery lifetime requirement specified by 3GPP can be met with proper configuration of traffic profile, transmission, and network parameters.Comment: submitted to IEEE Internet of Things Journal, 12 pages, 10 figure

A Survey on Long-Range Wide-Area Network Technology Optimizations

Long-Range Wide-Area Network (LoRaWAN) enables flexible long-range service communications with low power consumption which is suitable for many IoT applications. The densification of LoRaWAN, which is needed to meet a wide range of IoT networking requirements, poses further challenges. For instance, the deployment of gateways and IoT devices are widely deployed in urban areas, which leads to interference caused by concurrent transmissions on the same channel. In this context, it is crucial to understand aspects such as the coexistence of IoT devices and applications, resource allocation, Media Access Control (MAC) layer, network planning, and mobility support, that directly affect LoRaWAN’s performance.We present a systematic review of state-of-the-art works for LoRaWAN optimization solutions for IoT networking operations. We focus on five aspects that directly affect the performance of LoRaWAN. These specific aspects are directly associated with the challenges of densification of LoRaWAN. Based on the literature analysis, we present a taxonomy covering five aspects related to LoRaWAN optimizations for efficient IoT networks. Finally, we identify key research challenges and open issues in LoRaWAN optimizations for IoT networking operations that must be further studied in the future

Dissecting Energy Consumption of NB-IoT Devices Empirically

3GPP has recently introduced NB-IoT, a new mobile communication standard offering a robust and energy efficient connectivity option to the rapidly expanding market of Internet of Things (IoT) devices. To unleash its full potential, end-devices are expected to work in a plug and play fashion, with zero or minimal parameters configuration, still exhibiting excellent energy efficiency. We perform the most comprehensive set of empirical measurements with commercial IoT devices and different operators to date, quantifying the impact of several parameters to energy consumption. Our campaign proves that parameters setting does impact energy consumption, so proper configuration is necessary. We shed light on this aspect by first illustrating how the nominal standard operational modes map into real current consumption patterns of NB-IoT devices. Further, we investigate which device reported metadata metrics better reflect performance and implement an algorithm to automatically identify device state in current time series logs. Then, we provide a measurement-driven analysis of the energy consumption and network performance of two popular NB-IoT boards under different parameter configurations and with two major western European operators. We observed that energy consumption is mostly affected by the paging interval in Connected state, set by the base station. However, not all operators correctly implement such settings. Furthermore, under the default configuration, energy consumption in not strongly affected by packet size nor by signal quality, unless it is extremely bad. Our observations indicate that simple modifications to the default parameters settings can yield great energy savings.Comment: 18 pages, 25 figures, IEEE journal format, all Figures recreated for better readability, new section with results summar