Major breakthrough on mmWave propagation and channel modeling

Understanding radio propagation in the mmWave frequency range is vital for the development of 5G. Ericsson Research experts, in partnership with European researchers in the mmMAGIC project, have performed extensive mmWave channel measurements and modeling for a multitude of scenarios. Let’s look at our key achievements.

Present cellular communications systems utilize frequencies below 6 GHz. The frequency range 24-86 GHz – which is subject for allocation within International Mobile Telecommunication 2020 (IMT-2020) spectrum at the World Radiocommunication Conference 2019 – is however mainly in the mmWave range. Compared with below 6 GHz, loss in radio signal due to absorption in materials or blockage by buildings, vegetation, vehicles, and humans is expected to be substantially different in the mmWave range. Moreover, important radio channel characteristics such as multi-path delay spread and directional spread have previously been poorly understood in the mmWave range.

To overcome this knowledge gap, the mmMAGIC project (co-funded by the European Commission’s H2020 program) has undertaken a major effort in the area of propagation research with extensive measurement campaigns performed over 2-80 GHz for a multitude of different indoor and outdoor scenarios. In addition, researchers have performed simulation campaigns in selected popular environments and frequencies to provide a large data set of propagation channels for the purpose of channel modelling. Overall, 54 single-frequency equivalent campaigns have been conducted. An overview of these measurements and simulations is depicted in figure below.

Requirements for channel measurements

The assessment of any frequency dependency over the measured range is key in the development of 5G mobile communications and spectrum allocation. To ensure comparability between channel measurements at different frequencies, a set of important requirements have been established:

  • Equal measurement bandwidth
  • Equal antenna pattern, either physical or synthesized
  • Equal dynamic range for analysis both in delay and angle domains
  • Equal angle resolution (for example, array size equal in terms of number of lambda)
  • Same environment and same antenna locations

The measurement data in the mmMAGIC project has been thoroughly analyzed assuring that the above requirements were fulfilled.

Key results and contributions in channel modeling

Based on channel measurements and thorough analysis, the key characteristics of mmWave propagation can now be largely understood. All details are publicly available in the project’s final report Measurement Results and Final mmMAGIC Channel Models. The key results have, to a large extent, already been incorporated into propagation models in 3GPP and ITU-R, as listed below:

  1. Extensive high quality measurement data contributed to 3GPP 5G channel modeling.
  2. Measurements and modeling of building penetration loss used as substantial input to 3GPP and ITU-R models.
  3. A substantially improved blockage model adopted by ITU-R.
  4. Addition of ground reflection added to ITU-R IMT2020 channel model.

Thorough statistical analysis (determining confidence ranges shown in the figure) of frequency dependency of delay spread and angle spread, with no significant frequency dependency observed, in contrast to the less thorough result of the 3GPP modelling effort.

Indoor measurement of angle spread in line of sight (LOS) and non-line of sight (NLOS)
Indoor measurement of angle spread in line of sight (LOS) and non-line of sight (NLOS)
Frequency dependence of RMS delay spread of the 3GPP and mmMAGIC channel models. The confidence ranges of the mmMAGIC model are indicated with dashed lines.
Frequency dependence of RMS delay spread of the 3GPP and mmMAGIC channel models. The confidence ranges of the mmMAGIC model are indicated with dashed lines.

 

mmMAGIC project

The mmMAGIC consortium comprises of 18 organizations in Europe (Samsung, Ericsson, Huawei, Nokia, Alcatel-Lucent, Intel, Orange, Telefonica, Keysight Technologies, Rhode & Schwarz, HHI, CEA-Leti, Imdea Networks, Bristol University, Chalmers University, TU Dresden, Qamcom, Aatlo University). For details on the mmWave radio interface design, please visit the project webpage.

Author: Ali Zaidi

Towards future challenges for SATCOM-On-The-Move systems

telxperts telecom trainings

b1SATCOM-On-The-Move (SOTM) stands for Satellite Communication on the move, a mobile satellite technology, which is mostly used for military purposes. A vehicle mounted with SATCOM antenna can access satellite or space station even when it is moving. This is an important part of military warfare. There are a number of benefits of deploying this communication technology. Some of the key benefits of SOTM are: it guarantees the effectiveness of warfare, lethality, and survivability. These key benefits have made SOTM a fundamental defense communication system. Initially, it was only used by US military for defense purposes. Later on, it surfaced as a commercial commodity. Hence, commercial satellite industry emerged as a new sector. Figure 1 illustrates a mobile vehicle using satellite technology used in military agencies.

What are the applications of SATCOM on the Move Systems?

When a satellite revolves over the equator of the Earth, it can transmit signals to the extremes of both north and south of a longitude. In summary, when a satellite is hovering along any one longitude of the earth, the station on earth can receive data signals from any point on the ground.   Undoubtedly, with SOTM the defense technology has taken a leap.

What are the future challenges faced by the SOTM Technology?

b2However, there are some potential challenges faced by this technology. Challenges can be based on weight, size, Radio frequency, Protocols of the networking, data rate, and above all vehicle platform dynamics. On the basis of the technical specifications, there are different types of SOTM devices. Portability of the device is the most vital challenge faced by the manufacturers of the SATCOM-enabled products for vehicles. The lighter the device, more acceptability it will get.   Another challenge faced by SOTM is the outage of the radio frequency used for operating and connecting the device for a time period. Interruption can be caused due to bad weather conditions and lack of connectivity inside the tunnels. However, if SOTM device is powerful enough, it can resume operation once you are out of the obtrusion.

Telxperts provides intensive learning to SOTM systems, latest technologies and performance in this training course. This training course focuses on SATCOM services, SOTM fundamentals, techniques, Orbital and spectrum consideration for SOTM and Satellite Communication Evolution to Protected Satellite Communication.


About Author:

Dr. Hafiz Yasar Lateef – one of the founding members of TelXperts – has several years of experience on Satellite Communication and SOTM. He is a Member of IEEE Communications Society and frequently features as a keynote speaker at various international conferences and workshops. His expertise encompass Satellite Communication, Satellite communication on the move, Voice over LTE (VoLTE), 5G, Internet of Things, Big Data Analytics, LTE radio network planning and optimization, Small cells & DAS planning & Optimization, Self-Organizing Networks (SON) and Green cellular networks. Dr. Hafiz Yasar Lateef’s Biography has been featured on Bristol Who’s Who famous personalities registry for his excellent research work in the field of Telecommunication. His work on the areas of MIMO techniques for wireless networks, Green Cellular Networks and Self-Organizing cellular networks have already found their way into telecommunication standards. He has authored and co-authored numerous international journals and conference papers in the field of LTE/LTE-Advanced wireless networks.

Dr. Yasar holds a Doctorate degree in the field of Telecommunications from University of Leeds, UK. He has participated in various international projects on future wireless networks in collaboration with ZTE Corporation, Texas A&M, Politecnico Di Torino Italy, King’s College London, CTTC Spain and CCSR University of Surrey. In the past, he held various roles at ZTE Corporation, University of Leeds, UK, University of Bedfordshire, UK, Qatar University, QMIC and Texas A&M, Curtin University, Australia.