Hands-On Experience with UWB : Angle of Arrival Accuracy Evaluation in Channel 9

This paper evaluates IEEE 802.15.4z standard- compliant NXP SR040 and SR150 chips in Angle of Arrival (AoA) capabilities in Channel 9 (7.737—8.237 GHz) of the Ultra-WideBand (UWB) spectrum. Due to the shorter wavelength, higher frequencies may encounter certain limitations when it comes to harsh environments, as more reflections and multipath propagation can occur. Furthermore, they also can be affected by their enclosure used to protect the electronics in such an environment, which needs to be taken into account during product design. This work presents the results of the evaluation measurement scenario relatable to real-life use cases and concludes potentially valuable insight important for consideration when creating a new UWB product. Besides a basic overview of the theoretical estimation of AoA by Time Difference of Arrival (TDoA) and Phase Difference of Arrival (PDoA), and the evaluation of the corresponding results, the main contribution is the repeatable topology considered for the conducted measurements. The presented results allow vendors to compare their solutions with the various radio chips or antenna configurations.acceptedVersionPeer reviewe

Performance Analysis of Different LoRaWAN Frequency Bands for mMTC Scenarios

The possibility of utilizing different frequencies for the LoRaWAN is a key component which, together with the other parameters, i.e., (i) bandwidth, (ii) spreading factor, (iii) coding rate, and (iv) transmission power, defines the communication performance. In this paper, we present the substantive im- provements for both the end devices and the radio access network (gateways) to enhance the data rates and decrease the communication latency. The implementation changes were made for the publicly available LoRaWAN module “signetlabdei” for Network Simulator 3. Utilizing the frequency 2.4GHz, the transmission time in the LoRaWAN network has improved by 80 % decreasing from 75 ms to 14 ms. The frequency 2.4 GHz for the EU region also showed the best performance due to the extended bandwidth (transmission success above 90%) in the case of the mMTC scenario with thousands of devices deployed. Together with the updated LoRaWAN module, the reported results are expected to serve as a building block for mMTC- oriented simulation scenarios.acceptedVersionPeer reviewe

LWM2M for Cellular IoT : Protocol Implementation and Performance Evaluation

With the growing number of IoT devices, numerous IoT protocols are being developed to provide the market with options based on product requirements. With the release of cellular IoT (CIoT) technologies in the Czech Republic, recently LTE Cat-M, the focus shifts towards not only satisfying the requirements of the device application but also minimizing the generated traffic and overall co-existence of many devices under one cell. It led to the modification of the existing and the creation of new IoT protocols designed to generate as little overhead traffic as possible while adopting the existing well- known communication schemes. Namely, the new UDP-based protocol for IoT, LWM2M strives to be the alternative to the well-established IoT protocols used outside of CIoT. This paper explains the communication principles and capabilities of the well-established IoT protocols with a heavy focus on the LWM2M protocol. Further, it describes difficulties during user implementation of the LWM2M protocol. Furthermore, two carefully designed scenarios are used to compare the differences among these protocols, focusing on generated overhead as it is subject to a fee paid to the network operators within the CIoT networks.Peer reviewe

Pitfalls of LPWA Power Consumption: Hands-On Design of Current Probe

The unique opportunities introduced by the emerging Industrial Internet of Things (IIoT) applications have accelerated the momentum of the massive Machine-Type Communications (mMTC) worldwide. As the number of already deployed Low-Power Wide-Area (LPWA) applications growth exponentially over the last decade, new open challenges started to be discussed across the industry sector. The most critical parameter of the LWPA devices in question is energy efficiency and the overall power consumption of designed end-devices. Therefore, the need for precise measurement of power consumption has attracted engineers’ attention as the unique communication parameters of the LPWA devices form the current consumption measurements challenging task. To facilitate accurate current measurements ranging between hundreds of nA and hundreds of µA, we propose a unique design of the current probe prototype. We then demonstrate the obtained results concerning the accuracy, measurement range switching, and sufficient sampling speed. All the measurements from the designed prototype are further compared with the industry-grade DC power analyzer Agilent N6705B.acceptedVersionPeer reviewe