Ignacio Rodriguez Larrad

• Ph.D. Wireless Communications
• Ramon y Cajal Research Fellow at University of Oviedo

5G cellular networks are now a reality and promise to improve key performance indicators (KPIs), such as Gbps data rates and latencies in the order of milliseconds. While some of these KPIs are achievable in urban scenarios, rural areas often face challenging connectivity conditions due to the lack of terrestrial network (TN) infrastructure. To sol...

In this article, we propose a distributed synchronization solution to achieve decentralized coordination in a system of collaborative robots. This is done by leveraging cloud-based computing and 5G technology to exchange causal ordering messages between the robots, eliminating the need for centralized control entities or programmable logic controll...

Real-time locating systems (RTLSs) have proven to be a practical and effective solution for monitoring positions/status of humans and other entities in industrial environments, ensuring safe and efficient automated operations, by responding in real-time to unexpected events, such as the proximity of human workers to autonomous mobile robots (AMRs)....

Industrial environments constitute a challenge in terms of radio propagation due to the presence of machinery and the mobility of the different agents, especially at mmWave bands. This paper presents an experimental evaluation of a FR2 5G network deployed in an operational factory scenario at 26 GHz. The experimental characterization, performed wit...

This work presents the analysis of a measurement campaign performed in a realistic two-hall industrial environment for FR2 band. In order to provide secure, reliable and high available Machine-to-Machine communications in the mmWave band for Industrial Internet of Things mobile applications, a study of the physical propagation channel must be carri...

Indoor positioning systems are essential in the industrial domain for optimized production and safe operation of mobile elements, such as mobile robots, especially in the presence of static machinery and human operators. In this paper, we assess the performance of a commercial UWB radio-based positioning system deployed in a realistic industrial sc...

Directional measurements of over 2600 links in four distinct factories at 28 GHz are used to formulate the path gain and azimuth gain models to allow reliable 90% coverage estimates. A simple theoretical model of path gain, dependent on ceiling and clutter heights, is found to represent path gain across the four factories with 4.4 dB root-mean-squa...

Evaluations of different technologies and solutions for indoor localization exist but only a few are aimed at the industrial context. In this paper, we compare and analyze two prominent solutions based on Ultra Wide Band Radio (Pozyx) and Ultrasound (GoT), both installed in an industrial manufacturing laboratory. The comparison comprises a static a...

Wireless technology is envisioned to be a major enabler of flexible industrial deployments, allowing agile installations and mobility of production elements. However, for industrial IoT (IIoT) use-cases, reliability and service availability remain as key concerns for wide adoption. To enhance wireless link reliability, we propose in this paper a Se...

Data-driven agriculture and Internet of Farming (IoF) require reliable communication systems. Nowadays, only some of the key use cases demanded by the agricultural industry verticals get support from multiple state of the art wireless technologies such as 4G, Wi-Fi, or Low Power Wide Area Network (LPWAN) technologies, combined with satellite and cl...

The fourth industrial revolution, or Industry 4.0 (I4.0), makes use of wireless technologies together with other industrial Internet-of-Things (IIoT) technologies, cyber–physical systems (CPS), and edge computing to enable the optimization and the faster re-configuration of industrial production processes. As I4.0 deployments are ramping up, the pr...

This paper investigates the impact of wireless communication in manufacturing systems. By using a digital twin representation of a real production line, a production throughput evaluation is performed for various configurations considering different wireless control communication schemes over Wi-Fi, 4G LTE and 5G NR. The results show that operating...

This article presents an overview of current Industry 4.0 applied research topics, addressed from both the industrial production and wireless communication points of view. A roadmap toward achieving the more advanced industrial manufacturing visions and concepts, such as “swarm production” (nonlinear and fully decentralized production) is defined,...

5G and beyond sees an ever increasing density of connected things. As not all devices are coordinated, there are limited opportunities to mitigate interference. As such, it is crucial to characterize the interference in order to understand its impact on coding, waveform and receiver design. While a number of theoretical models have been developed f...

The continuous proliferation of applications requiring wireless connectivity will eventually result in latency and reliability requirements beyond what is achievable with current technologies. Such applications can for example include industrial control at the sensor-actuator level, intra-vehicle communication , fast closed loop control in intra-bo...

The upcoming 5th generation (5G) wireless technology application areas bring new communication performance requirements, mainly in terms of reliability and latency, but also in terms of radio planning, where further detailed characterization of the wireless channel is needed. To address these demands, we developed an agile multi-node multi-antenna...

One of the 5G use cases, known as ultra-reliable communication (URC), is expected to support very low packet error rate on the order of 10 −5 with a 1 ms latency. In an industrial scenario, this would make possible replacing wired connections with wireless for controlling critical processes. Industrial environments with large metallic machinery and...

In this paper, we investigate the suitability of the propagation models ITU-R 526, Okumura Hata, COST Hata models and Standard Propagation Model (SPM) to predict the path loss in open-pit mines. The models are evaluated by comparing the predicted data with measurements obtained in two operational iron-ore mining complexes in Brazil. Additionally, a...

The ITU-R 1 has recently published a new Recommendation giving a method for the estimation of building entry loss at frequencies between 100 MHz and 100 GHz. This paper describes the derivation and form of the new model and highlights work that remains to be done in this area.

5G will play a pivotal role in the digitization of the industrial sector and is expected to make the best use of every bit of spectrum available. In this light, this paper presents the results of an extensive measurement campaign in two iron-ore open-pit mining complexes, at the 700 MHz and 2.6 GHz bands, considering macro and small cell deployment...

In this paper we present the results of an extensive measurement campaign performed at two large iron ore mining centers in Brazil at the 2.6 GHz band. Although several studies focusing on radio propagation in underground mines have been published, measurement data and careful analyses for open-pit mines are still scarce. Our results aim at filling...

Long Term Evolution, the fourth generation of mobile communication technology, has been commercially deployed for about five years. Even though it is continuously updated through new releases, and with LTE Advanced Pro Release 13 being the latest one, the development of the fifth generation has been initiated. In this article, we measure how curren...

This letter presents an empirical multi-frequency outdoor-to-indoor path loss model. The model is based on measurements performed on the exact same set of scenarios for different frequency bands ranging from traditional cellular allocations below 6 GHz (0.8, 2, 3.5 and 5.2 GHz), up to cm-wave frequencies (10, 18 and 28 GHz). The model has applicabi...

Existing cellular technologies are rapidly coming to their performance limits. This is due not only to the growth in data traffic and in the number of connected terminals, but also because we are on the verge of new era, where everyone and everything will be connected, with more demanding and varied requirements that cannot be satisfied by current ne...

This paper compares three candidate large-scale propagation path loss models for use over the entire microwave and millimeter-wave (mmWave) radio spectrum: The alpha-beta-gamma (ABG) model, the close-in (CI) free-space reference distance model, and the CI model with a frequency-weighted path loss exponent (CIF). Each of these models has been recent...

The need for continuous safety improvements and increased operational efficiency is driving the mining industry through a transition toward automated operations. From a communications perspective, this transition introduces a new set of high-bandwidth business-critical and mission-critical applications that need to be met by the wireless network. T...

This paper compares three candidate large-scale propagation path loss models for use over the entire microwave and millimeter-wave (mmWave) radio spectrum: the alpha-beta-gamma (ABG) model, the close-in (CI) free space reference distance model, and the CI model with a frequency-weighted path loss exponent (CIF). Each of these models have been recen...

It is likely that 5G wireless systems will encompass frequencies from around 500 MHz all the way to around 100 GHz. To adequately assess the performance of 5G systems in these different bands, path loss (PL) models will need to be developed across this wide frequency range. The PL models can roughly be broken into two categories, ones that have som...

This paper presents and compares two candidate large-scale propagation path loss models, the alpha-beta-gamma (ABG) model and the close-in (CI) free space reference distance model, for the design of fifth generation (5G) wireless communication systems in urban micro- and macro-cellular scenarios. Comparisons are made using the data obtained from 20...

This paper presents key parameters including the line-of-sight (LOS) probability, large-scale path loss, and shadow fading models for the design of future fifth generation (5G) wireless communication systems in urban macro-cellular (UMa) scenarios, using the data obtained from propagation measurements at 38 GHz in Austin, US, and at 2, 10, 18, and...

The characteristics of the deployment scenario are fundamental elements in the performance evaluation of wireless networks inter-cell interference coordination (ICIC) schemes. The statistical validation of such concepts is typically achieved by means of system-level simulation campaigns where regular reference scenarios and stochastic channel model...

In real urban deployments, base station antennas are typically not placed in free space conditions. Therefore, the radiation pattern can be affected by mounting structures and nearby obstacles located in the proximity of the antenna (near-field), which are often not taken into consideration. Also the intrinsic propagation mechanisms of the urban en...

Energy-efficient buildings are gaining momentum in order to comply with the new energy regulations. Especially in northern cold countries, thick reinforced walls and energy-efficient windows composed of several layers of glass plus metal coating are becoming the de facto elements in modern building constructions, and it has been noticed that they c...

In this paper HSPA Release 6 femto and IEEE 802.11g WiFi indoor data solutions are investigated from an end user perspective. Femto and WiFi access points are deployed at typical locations in an urban environment and end user performance is measured. Three key performance indicators (KPI) were defined - downlink and uplink user data rates, latency...

WiFi is the prevalent wireless access technology in local area deployments and is expected to play a major role in a mobile operator's data offloading strategy. As a result, having simple tools that are able to assess the offloading potential of IEEE 802.11 networks is vital. In this paper, we propose a simple closed-form solution to calculate down...

Despite being a simple and commonly-applied radio optimization technique, the impact on practical network performance from base station antenna downtilt is not well understood. Most published studies based on empirical path loss models report tilt angles and performance gains that are far higher than practical experience suggests. We motivate in th...

The 3.5 GHz band is a strong candidate for future urban micro cell deployment with base station antennas located below rooftop. Compared to other frequency bands, propagation in the 3.5 GHz band is relatively unexplored for the micro cell deployment. This paper presents a measurement-based analysis of outdoor and outdoor-to-indoor propagation at 3....

Base station antenna downtilt is one of the most important parameters for optimizing a cellular network with tight frequency reuse. By downtilting, inter-site interference is reduced, which leads to an improved performance of the network. In this study we show that a simple geometrical-based extension to standard empirical path loss prediction mode...

Relay base stations are expected to play an important role in extending coverage for beyond 3G networks, such as LTE-A. However, the signal quality experienced on the backhaul link between the macro-cell and the relay node has a major impact on the performance of the multi-hop transmission. This paper presents a measurement-based study focusing on...