As we all move forward and new technologies emerge with exciting applications, they will all depend greatly on the signal coverage and availability from next generation wireless networks.  With the emerging 5G NR networks expected to be built from 2020 and beyond, new enhanced mobile broadband (eMBB) connections will need to provide data rates at 50, 100, or even 300 Mbps.  While the theoretical data rates for 5G boast higher speeds, those speeds are not expected to be available due to coverage issues and carriers throttling the speeds to better share the capacity of the networks.

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With the three bands available, the data rates will vary depending upon which band you can access.  Not all bands will be deployed everywhere.  The band plans will vary by country as well.  Many countries have yet to fully define what frequencies they will use in each band.  In general terms, these three 5G bands are:

Low-band spectrum is currently being used for 2G, 3G and 4G services for voice, MBB services and Internet of Things (IoT).  Newly allocated spectrum for mobile networks include the 600 MHz and 700 MHz bands.  These bands are ideal for wide-area and outside-in coverage as well as for deep indoor coverage, typically required for eMBB and voice services.

Mid-band spectrum is currently used for 2G, 3G and 4G services.  New spectrum has been widely allocated in the 3.5 GHz band, with more spectrum planned to be made available in the 1.5 GHz (L-band) and 5 GHz (unlicensed) bands.  Bandwidths of 50 megahertz to 100 megahertz per network will enable high-capacity and low-latency networks ideal for 5G use cases such as enhanced MBB (eMBB) and Ultra Reliable Low Latency Communications (URLLC), for critical IoT applications.  With better wide-area and indoor coverage than high-band spectrum, the mid-band spectrum is an optimal compromise between coverage, quality, throughput, capacity and latency. Combining the mid-band spectrum with low-band spectrum leads to exceptional network improvements in terms of capacity and efficiency.

High-band spectrum clearly provides the anticipated leap in data speed, capacity, quality and low latency promised by 5G.  New spectrum bands are typically in the range 24 GHz to 50 GHz, with contiguous bandwidths of more than 100 megahertz per network.  The high-band provides a significant opportunity for very high throughput services for eMBB, localized deployments and low latency use cases, e.g. industrial IoT, venues, etc, both for indoor and outdoor deployments. Fixed wireless access (FWA) will also benefit from these higher bands in terms of capacity. For wider-area coverage, combinations with low-band and mid-band are essential.

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How fast will 5G networks be?  Tests indicate that speeds will jump nearly 10 times faster than the current 4G LTE networks.  Others in the industry claim that connections will be 30-50 times faster.  The numbers vary greatly, and only time will tell what changes 5G will bring about.  The speed is a result of new spectrum that offers broadband carriers operating with higher orders of modulation.  The three bands are defined as follows:

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But before various mobile wireless providers begin making promises about their coverage and network speeds, there is one key issue facing any speculative 5G network – it requires new radio systems composed of transmitters, antennas, and cabling.

Why are new radio systems needed?  In a nutshell, 5G networks will be operated on higher frequencies than current consumer networks.  The higher frequency signal provides speed, but signals do not reach as far and are more easily hindered by line-of-sight issues.  Thus, a significant amount of resources are required to decide where new transmitters should be built.

Rather then guessing or simply installing these new radios at the existing 4G cell sites. the smart approach is to prepare computer generated models of the coverage in a software tool to predict what the coverage will look like if the new 5G site is to be implemented.  Older RF prediction software tools used for other radio systems will not work for 5G since the technical parameters are so dramatically different compared to previous radio solutions.  Examples of the technical differences include: ultra low latency, beamforming, 8×8 MIMO, higher order modulation at 1024 QAM, different band frequencies, different characterization of the RF signals as a result of the frequency and how they interact with obstructions, and much more.

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Ray-Tracing Propagation Model

Compared with traditional 3G/4G networks, 5G networks will be more complex.  With the emergence of Massive MIMO and beam forming technologies, multipath modelling is of greater importance.

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However, due to the lack of multipath information at a high level of granularity, the accuracy of network planning is hard to guarantee.  Therefore, a ray-tracing propagation model established upon high-precision electronic maps and multipath modelling plays an irreplaceable role in 5G wireless network planning.  The beam-based ray-tracing propagation model includes the following types of features.

  • Direct radiation: The transmitter and receiver are not affected by tall buildings or dense vegetation in the first Fresnel zone.  The direct radiation power constitutes the main power source of the received signals.  The power of the signals reflected by grounds or walls can be ignored.
  • Reflection: When reflection occurs, the incident ray, reflection ray, and reflection point are in the same plane.  The angle between the incident ray and the reflection point is equal to the angle between the reflection ray and the normal line of the reflection point.  The ray-tracing reflection model is established based on the preceding description.
  • Diffraction: The condition of diffraction concurrence is related to the wavelength of the electromagnetic wave and the size of the obstacle edge.  Diffraction can bring great propagation power in sub-6 GHz bands.  However, when the frequency band is 10 GHz or higher, the number of edges that can produce diffraction is reduced, and so is the resulting power generated by diffraction.
  • Signal transmission: The transmission and reflection of electromagnetic waves occur at the junction of two kinds of media.  The transmission energy is related to the dielectric constant and permeability of the penetrated material.
  • Combined paths (diffraction after reflection and reflection after diffraction): The transmission mode of multiple paths combined cannot be marginalized.  It is also a potential candidate power propagation method that can be used for the ray-tracing propagation model.  The ray-tracing propagation model can automatically identify the preceding electromagnetic wave propagation paths based on the high-precision electronic map and the position of the receiver.  This can lead to higher accuracy during network planning.

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3D Coverage Prediction

In the future, more and more traffic will occur indoors.  Therefore, 3D planning and simulation technologies are crucial to 5G network construction.  Some manufacturers, such as Huawei has developed the 3D coverage prediction function to extend the simulation range from a traditional 2D plane to a 3D space.  Multiple coverage indicators on different floors can be displayed.

  • 3D space modeling: Use an electronic map providing important information for large structures (location, silhouette, and height) to construct a 3D model.
  • 3D propagation model: 3D simulation and 2D outdoor simulation differ greatly in terms of the radio signal propagation environment.  Therefore, the traditional propagation models coverage prediction result provided by legacy RF propagation modelling tools cannot be used and the modeling of radio signal penetration and transceiver height need to be established.
  • 3D prediction: signal level, interference, signal quality, throughput and others of the pilot as well as the traffic channels can be predicted in 3D scenarios.

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The timely rollout of 5G networks will become increasingly important to achieve the productivity benefits desired by industrial policy, as well as dealing with digital divide issues.  The contribution of this article is the quantification of the cost, coverage and rollout implications of 5G based on different policy options.  Indeed, as the rollout of telecommunications infrastructure is inherently spatial and temporal, this is a necessary exploit and one that is becoming increasingly valuable considering the geographical disparities in provision that have arisen in the rollout of previous generations.

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Further research needs to focus on refining the costs of both spectrum and infrastructure deployment (including exploring backhaul costs), calibration of investment levels against coverage obligations, and the rollout of 5G in relation to competition, pricing and take-up.  Indeed, greater refinement and exploration of the time lag taken for rollout between different levels of capital expenditure would help decision-making processes involving both operators and government.  Moreover, sensitivity analysis is one key tool that can help to identify the cost boundaries which have the largest impact on telecommunications coverage and capacity, and should be explored in future work.  While the focus here was on network coverage, the increased spectral efficiency gains of 5G is an area of future uncertainty that requires analysis.


References:

Ericsson. (2019). Spectrum Strategies. Telefonaktiebolaget LM Ericsson. Retrieved on October 10, 2019 from, https://www.ericsson.com/en/networks/trending/hot-topics/5g-spectrum-strategies-to-maximize-all-bands

Huawei. (2019). Huawei 5G Wireless Network Planning Solution White Paper. Huawei Technologies Co. Ltd. Retrieved on October 20, 2019 from, https://www-file.huawei.com/-/media/corporate/pdf/white%20paper/2018/5g_wireless_network_planing_solution_en.pdf?la=en-ch

Oughton, E., & Frias, Z. (2018). The cost, coverage and rollout implications of 5G infrastructure in Britain. Science Direct. Retrieved on October 20, 2019 from, https://doi.org/10.1016/j.telpol.2017.07.009

Walker, E. (2019). This is how you use 3D maps to build better 5G networks. Disqus. Retrieved on October 20, 2019 from, https://360.here.com/infosys-and-here-to-improve-5g-costs


About the Author:

Michael Martin has more than 35 years of experience in systems design for broadband networks, optical fibre, wireless, and digital communications technologies.

He is a business and technology consultant. Over the past 15 years with IBM, he has worked in the GBS Global Center of Competency for Energy and Utilities and the GTS Global Center of Excellence for Energy and Utilities. He is a founding partner and President of MICAN Communications and before that was President of Comlink Systems Limited and Ensat Broadcast Services, Inc., both divisions of Cygnal Technologies Corporation (CYN: TSX).

Martin currently serves on the Board of Directors for TeraGo Inc (TGO: TSX) and previously served on the Board of Directors for Avante Logixx Inc. (XX: TSX.V). 

He has served as a Member, SCC ISO-IEC JTC 1/SC-41 – Internet of Things and related technologies, ISO – International Organization for Standardization, and as a member of the NIST SP 500-325 Fog Computing Conceptual Model, National Institute of Standards and Technology.

He served on the Board of Governors of the University of Ontario Institute of Technology (UOIT) [now OntarioTech University] and on the Board of Advisers of five different Colleges in Ontario.  For 16 years he served on the Board of the Society of Motion Picture and Television Engineers (SMPTE), Toronto Section. 

He holds three master’s degrees, in business (MBA), communication (MA), and education (MEd). As well, he has three undergraduate diplomas and five certifications in business, computer programming, internetworking, project management, media, photography, and communication technology. He has earned 15 badges in next generation MOOC continuous education in IoT, Cloud, AI and Cognitive systems, Blockchain, Agile, Big Data, Design Thinking, Security, and more.