Internet of things

Summary

The Internet of things (IoT) describes devices with sensors, processing ability, software and other technologies that connect and exchange data with other devices and systems over the Internet or other communications networks. The Internet of things encompasses electronics, communication and computer science engineering. Internet of things has been considered a misnomer because devices do not need to be connected to the public internet, they only need to be connected to a network, and be individually addressable. The field has evolved due to the convergence of multiple technologies, including ubiquitous computing, commodity sensors, and increasingly powerful embedded systems, as well as machine learning. Older fields of embedded systems, wireless sensor networks, control systems, automation (including home and building automation), independently and collectively enable the Internet of things. In the consumer market, IoT technology is most synonymous with "smart home" products, incl

Official source

https://en.wikipedia.org/wiki/Internet_of_things

About this result

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Related publications (62)

Related publications

Related people (4)

Related people

Related units (6)

Related units

Related concepts (139)

Related concepts

Related courses (54)

Related courses

Related lectures (77)

Related lectures

An Open-Source LoRa Physical Layer Prototype on GNU Radio

Orion Afisiadis, Alexios Konstantinos Balatsoukas Stimming, Andreas Peter Burg, Paul Angelin Antoine Mayoraz, Joachim Tobias Tapparel

LoRa is the proprietary physical layer (PHY) of LoRaWAN, which is a popular Internet-of-Things (IoT) protocol enabling low-power devices to communicate over long ranges. A number of reverse engineering attempts have been published in the last few years that helped to reveal many of the LoRa PHY details. In this work, we describe our standard-compatible LoRa PHY software-defined radio (SDR) prototype based on GNU Radio. We show how this SDR prototype can be used to develop and evaluate receiver algorithms for LoRa. As an example, we describe the sampling time offset and the carrier frequency offset estimation and compensation blocks. We experimentally evaluate the error rate of LoRa, both for the uncoded and the coded cases, to illustrate that our publicly available open-source implementation is a solid basis for further research.

IEEE2020

A Low-Complexity LoRa Synchronization Algorithm Robust to Sampling Time Offsets

Orion Afisiadis, Mathieu Pierre Xhonneux

LoRaWAN is nowadays one of the most popular protocols for low-power Internet of Things communications. Although its physical layer, namely LoRa, has been thoroughly studied in the literature, aspects related to the synchronization of LoRa receivers have received little attention so far. The estimation and correction of carrier frequency and sampling time offsets (STOs) are, however, crucial to attain the low sensitivity levels offered by the LoRa spread-spectrum modulation. The goal of this article is to build a low-complexity, yet efficient synchronization algorithm capable of correcting both offsets. To this end, a complete analytical model of a LoRa signal corrupted by these offsets is first derived. Using this model, we propose a new estimator for the STO. We also show that the estimations of the carrier frequency and the STOs cannot be performed independently. Therefore, to avoid a complex joint estimation of both offsets, an iterative low-complexity synchronization algorithm is proposed. To reach a packet error rate of 10(-3), performance evaluations show that the proposed receiver requires only 1 or 2 dB higher signal-to-noise ratio than a theoretical perfectly synchronized receiver, while incurring a very low computational overhead.

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2022

, ,

LoRaWAN is a low-power wireless technology that provides long-range connectivity to battery-powered Internet of Things (IoT) devices. To minimize the energy consumption of the IoT nodes, LoRaWAN networks use for the uplink a pure non-slotted ALOHA multiple access scheme. Since the devices are not synchronized in time, collisions between uplink packets are the main source of errors when the number of nodes becomes important. To improve the reliability of dense LoRaWAN networks, we propose in this paper a successive interference cancellation LoRa receiver capable of decoding frames from two colliding users. The proposed two-user detector leverages the bit-interleaved coded modulation scheme of LoRa to improve the detection and cancellation of the strongest interfering user. We show that in the presence of two interfering users, the usage of a low coding-rate and iterative soft-detection are essential to attain error rates sufficiently close to the single-user scenario. Using network-level simulations, we subsequently evaluate the gains of our proposed two-user receiver in a realistic LoRaWAN network. To this end, we build advanced models of the studied receivers using Monte-Carlo simulations at the physical layer. For an overall packet error rate of 1%, simulation results indicate that a LoRaWAN network employing our two-user detector may serve 4.7 times more devices than a network with only a single-user receiver at the gateway.

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2021