Tuomo Hänninen

On the coverage of LPWANs: range evaluation and channel attenuation model for LoRa technology

In addition to long battery life and low cost, coverage is one of the most critical performance metrics for the low power wide area networks (LPWAN). In this work we study the coverage of the recently developed LoRa LPWAN technology via real-life measurements. The experiments were conducted in the city of Oulu, Finland, using the commercially available equipment. The measurements were executed for cases when a node located on ground (attached on the roof rack of a car) or on water (attached to the radio mast of a boat) reporting their data to a base station. For a node operating in the 868 MHz ISM band using 14 dBm transmit power and the maximum spreading factor, we have observed the maximum communication range of over 15 km on ground and close to 30 km on water. Besides the actual measurements, in the paper we also present a channel attenuation model derived from the measurement data. The model can be used to estimate the path loss in 868 MHz ISM band in an area similar to Oulu, Finland.

Cognitive Radio Trial Environment: First Live Authorized Shared Access-Based Spectrum-Sharing Demonstration

Cognitive radio system (CRS) technology can help respond to the growing mobile traffic demand by improving network resource usage and gaining access to new shared spectrum bands. This article presents a cognitive radio trial environment (CORE) consisting of cognitive engines (CEs) to control different radio systems [e.g., long-term evolution (LTE) and wireless open-access research platform (WARP)-based networks]. Load balancing and authorized shared access (ASA) are demonstrated using the trial environment with promising results. The ASA-based spectrum sharing trial is presented for the first time with a real-life mobile network accessing a shared spectrum band under a licensed shared access (LSA) regime. Cognitive decision making brings intelligence to the usage of the radio and network resources and, at best, increases considerably end users? quality of service (QoS) compared to the standard systems, as shown for QoS-based offloading.

Extensible modular wireless sensor and actuator network and IoT platform with plug&play module connection

Efficiency and flexibility are among the key requirements for Wireless Sensor and Actuator Networks (WSAN) of Internet of Things (IoT) era. In this work we present and demonstrate a novel WSAN and IoT platform. The new nodes are constructed by stacking together the different hardware modules encapsulating power sources, processing units, wired and wireless transceivers, sensors and actuators, or sets of those. Once a node is built, its processing unit can automatically identify all the connected hardware modules, obtain required software modules and tune nodes operation accounting for its structure, available resources and active applications.

Demo: Modular Multi-radio Wireless Sensor Platform for IoT Trials with Plug&Play Module Connection

In the paper we present and demonstrate the modular prototyping platform designed for trialing the Internet of Things (IoT) applications. The new devices are constructed by stacking together the various hardware modules encapsulating power sources, processing units, wired and wireless transceivers, sensors and actuators, or sets of those. The main processing unit automatically identifies all the attached modules and adjusts own operation accordingly. The demo will showcase how the platform can be used for building up multi-radio technology enabled wireless devices which will automatically form a heterogeneous wireless sensor and actuator network (WSAN). The possible use case scenarios and the ongoing research activities around the platform will be highlighted as well.

Implementation of spectrum sensing on wireless open-access research platform

Opportunistic spectrum usage is one application of the so called cognitive communication systems that enables efficient spectrum usage in future wireless communication systems. One of the key features in opportunistic spectrum usage is a spectrum opportunity estimation method. Energy detection has the benefit that knowledge about the licensed users is not required. In this paper, energy detection method called the localization algorithm based on double-thresholding (LAD) is implemented on the wireless open-access research platform (WARP). The simulation measurements proved that the implementation was done correctly. Results included important information of consumed FPGA resources and processing latencies for the LAD method implementation.

Field trial of the 3.5 GHz citizens broadband radio service governed by a spectrum access system (SAS)

In this paper, we describe a spectrum access system (SAS) based Citizens Broadband Radio Service (CBRS) field trial using a live LTE network in the 3.5 GHz band. The latest WInnForum specification guided the implementation of the relevant protocols for SAS operation. Here, we evaluate the performance of a CBRS field trial by using one of the most important performance indicators in a spectrum sharing scenario — the evacuation time. It indicates how rapidly the secondary user relinquishes the shared spectrum band to the primary user. Following the applied protocols, we measure and analyze the time scales for the evacuation and frequency change procedures in a field trial environment. Our work shows that the set time limits for the protection of primary users against interference are realistic when using commercially available mobile networks and equipment. Finally, utilizing knowledge of the latest base station models, we propose ways to reduce the evacuation and reconfiguration time by up to 70%.

Mechanisms for improving throughput and energy efficiency of Bluetooth Low Energy for multi node environment

Bluetooth Low Energy (BLE) is a recently developed energy-efficient short-range radio communication technology, which is nowa- days vastly becoming more and more popular. The technology aims to provide an energy-efficient low-cost wireless communication mechanism for a wide range of resource-limited consumer electronic devices and applications. In this paper we focus on the networking aspects of the tech- nology. First, we overview fundamentals of BLE communication technology, discuss its capabilities and limitations, and compare BLE with state-of-the-art technologies. Furthermore, we identify and discuss two scenarios, for which standard BLE communication mechanisms show poor performance and propose two mechanisms capable of improving throughput and energy efficiency of BLE communication in multi node environment. The efficiency of the proposed mechanisms is proved via network level simulations, which are executed using the developed BLE simulation tool. The results of the simulations are reported and discussed. We believe that the presented results might be of some interest not only for academic researchers but also for practicing engineers.

A channel allocation algorithm for Citizens Broadband Radio Service/Spectrum Access System

Recently, the Federal Communications Commission has proposed to create Citizens Broadband Radio Service (CBRS) with the three-tier spectrum sharing system to release more spectrum for the mobile broadband usage in the United States. At the moment, the Wireless Innovation Forum is involved in defining the operational and functional requirements for this framework based on [1], and also in standardizations. Evidently, the successful operation of this system depends on efficient channel allocation algorithms. In this paper, we consider the CBRS with the three-tier spectrum sharing system. A set of CBRS users, i.e., Priority Access License (PAL) and General Authorized Access (GAA) users are located in an area, which is divided into multiple census tracts. The PAL and GAA users request frequency channels from the spectrum access system (SAS). The role of the SAS is to allocate channels to these two types of users while providing interference protection to the incumbent users. For this setup, we consider the problem of channel allocation for PAL and GAA users. The objective is to allocate channels for these two types of users, while considering the channel allocation rules proposed in [1]. For this problem, we propose a channel allocation algorithm to be used by the SAS. The proposed algorithm allocates channels to the CBRS users in two steps: 1) allocate channels to the PAL users and 2) allocate channel to the GAA users. Numerically, we show that the proposed algorithm is able to allocate channels while satisfying the rules proposed in [1]. More importantly, this research provides new insights on investigating channel allocation algorithms in CBRS/SAS.

Minimum Separation Distance Calculations for Incumbent Protection in LSA

In this paper, we consider minimum separation distance calculations from the perspective of a real-life Licensed Shared Access (LSA) system in the 2.3 GHz band in Europe. In the LSA system, an LTE network shares spectrum resources with incumbent users, such as programme making and special events (PMSE) users, which need to be protected from harmful interference. Plenty of potential resources are available, in case the incumbent activity is occasional or localized. The sharing scenario requires realistic separation distances to be calculated to protect the incumbents. The minimum separation distances were calculated using methods presented in the ECC report on compatibility studies on 2.3 GHz band, but by using the parameters from the real-life LSA test network. With this work, we bridge the gap between theoretical research for incumbent protection and practical LSA deployment. In the process of defining new separation distances, discrepancies were found in the original example calculations.

Live demonstration: Modular multi-radio wireless sensor platform with plug&play modules connection

Summary form only given. The demo will present to the audience the new flexible research and development platform for Wireless Sensor and Actuator Networks (WSANs) and Internet of Things (IoT). The devices are built out of the hardware modules which are connected together in Plug&Play manner. The software modules are selected and optimized accounting for each nodes structure. The platform enables wide variety of system-level experiments for future WSANs and heterogeneous communication systems.