The success of 5G for both mobile and fixed wireless access will be built on deployment in wide contiguous blocks of spectrum. 5G extends the catalogue of applicable frequency bands compared to previous cellular network generations, bringing together new spectrum and the re-use of existing mobile bands to support a wide range of applications, industries and geographical locations. But what are these bands, and what role to they play in delivering a complete 5G experience? JOE BARRET looks into this.

In its latest 5G Spectrum Snapshot published in September 2020, GSA recorded 207 operators with licences issued for 5G bands worldwide, between them they hold more than 310 licences to use 5G spectrum bands. This clearly shows that operators are looking at multiple bands when it comes to deploying new 5G services.

Access to spectrum

Access to a broad range of spectrum resources is one of the main growth drivers for the deployment of mobile broadband, the Internet of Things (IoT), and fixed wireless access (FWA) services; conversely limited spectrum availability can be a restrictive factor for the expansion of services into new markets and industries. Different 5G spectrum frequency bands also offer a range of attributes in terms of coverage and capacity.

Telecom regulators around the world are recognising that a broad range of low- to mid- to high-band spectrum needs to be made available for mobile services. Even with delays caused by the disruption due to the Covid-19 pandemic, GSA research suggests there are still over 30 auctions/assignments possible before the end of 2020, including 20 expected to assign parts of the C-Band spectrum in the range 3.3 – 4.2 GHz and 18 planning to assign spectrum at 700 MHz.

With access to all three spectrum ranges critical to enabling outdoor and indoor coverage needs to be fully met, the mobile ecosystem of regulators, operators and vendors are working hard to deliver the complete set of mass-market 5G services through a sustainable business model that delivers the best socio-economic value.

High-band

5G millimetre wave (mmWave) spectrum offers large amounts of bandwidth to support far greater capacity, faster downloads and more subscribers. It is ideally suitable for high data throughput applications such as video communication, high-quality video streaming and applications such as virtual and augmented reality. This high-band spectrum is also suited to local area hot-spot coverage and supports in-building where data usage is highest and the greatest throughput is required.

At WRC-19, global spectrum regulators identified several mmWave frequency bands for 5G IMT, with around 17 GHz of spectrum for 5G in the 26, 40, 45, 47 and 66 GHz ranges identified for IMT, globally or regionally. This decision, which GSA welcomed, paved the way for governments and regulators around the world to make frequency bands available for ultra-fast 5G services in hotspots and home broadband environments by relying on a global ecosystem.

As mmWave spectrum becomes available, so operators are showing significant interest, with 127 operators identified by GSA as investing in 5G using spectrum between 24250 MHz and 29500 MHz, and bands n257, n258, n261 being a particular focus of investment. The momentum in this area is similarly being reflected in growing device activity; by end of August 2020 GSA had identified 32 devices (commercial and pre-commercial) with announced support for Band 257, n258 or n261; 17 of which were phones, and eight were CPE devices.

Mid-band

5G mid-band spectrum was agreed as part of the ITU WRC-19 process and included agreement on making available the 3300–4200 MHz frequency range. Often referred to as C-band spectrum for 5G, this mid-band spectrum range offers an optimal balance between coverage and capacity.

Medium Frequencies, operating above 2 GHz, provide the best compromise between capacity and coverage, meeting a large portion of the 5G/IMT-2020 requirements. The 5G mid-band spectrum range has the additional merit of offering the largest contiguous bandwidth available for IMT below 6 GHz.

As of end August 2020, GSA’s NTS database showed C-band spectrum has been a key early focus of investment by operators. 178 operators were investing in this mid-band spectrum (3300-4200 MHz), with 82 of those known to be actively deploying networks using Band n77 or Band n78.

C-band spectrum is already well supported with devices; while only 36 of the commercially available devices (18.9% of them) are understood to support services operating in mmWave spectrum, 88.9 per cent of the commercially available devices are known to support sub-6 GHz spectrum. By August GSA had catalogued 178 announced 5G devices positioned as supporting Band n78 or Band n77. The majority (117) of those were phones, followed by non-industrial CPE at 27 devices, with modules making up the next largest category at 23 announced devices.

Low-band

Low-band spectrum is important for expanding 5G NR coverage in all urban/suburban/rural deployment scenarios, ensuring service continuity across different geographies, enhancing service quality in indoor environments, and helping to close the digital divide.

Lower Frequencies ensure wide area coverage and fundamentally complement higher frequencies ensuring consistent wide area services, including deep in-building coverage. 5G services can also theoretically be deployed across many of the same sub-2 GHz spectrum ranges as LTE.

As of May 2020, GSA had identified 40 countries/territories that had announced formal (date-specified) plans for allocating 5G-suitable frequencies below 1 GHz before the end of 2022, including technology-neutral licences or licences for mobile broadband services. Of these, 35 of those are planning to auction/allocate spectrum at 700 MHz.

As 2G or 3G networks are decommissioned and countries/territories award new tranches of spectrum in the low band range more operators will deploy 5G at these frequencies to benefit from the coverage advantages this band offers.

Looking forward to the 5G future at WRC-23

At WRC-19, looking forward to the WRC-23 conference, national administrations agreed to study additional spectrum opportunities in the mid-band frequencies between 3.3 and 10.5 GHz, as well as spectrum below 1 GHz. The aim being to help enable 5G services to be more widely deployed geographically, including rural areas, as well as meet the anticipated increased traffic needs of population centres in the latter half of this decade.

GSA plays an active role throughout the four-year cycle of the ITU’s World Radiocommunication Conference. The outcomes of which pave the way for governments and regulators around the world to harmonise frequency bands for ultra-fast IMT/5G services, supporting an expanded global ecosystem and healthy market competition.

Today, the GSA Spectrum Group, of over 135 specialists from GSA Member companies, is undertaking industry technical and advocacy work as part of the preparations for WRC-23, where access to additional spectrum is a key topic to support future market growth. GSA is continuing to work with national regulators and administrators to harmonise global spectrum across low, mid- and high-band frequencies to ensure mobile services can meet the expanding services both industry and consumers are expecting in the coming years.

• Barrett is President, Global mobile Suppliers Association