India needs more mid-band spectrum to support 5G growth

Spectrum is a limited, natural and key resource. It has global importance. Adequate access to spectrum is the key for the expansion of mobile coverage. Spectrum has to be managed properly to allow equitable access among different users and services without causing harmful interference from one another as well as enabling and promoting new technologies. Right balance is required between regulatory requirements of spectrum to provide certainty to protect the consumers of spectrum and need to ensure flexibility for the development of new technology use cases. Spectrum management is an important tool with the government to optimise the use of this finite public resource.

After the Supreme Court verdict in 2012, the spectrum allocation is through the auction route only to the users in our country. The 5G spectrum auction was concluded successfully in the month of August 2022, and out of 7.2 GHz of spectrum put for auction, 71 per cent of spectrum was acquired by the TSPs (Telecom Service Providers) in low, medium and high bands to suit the requirements of their various 5G use cases. Unlike 4G, 5G uses a broader frequency spectrum, ensuring faster data speeds and capacity.

Various frequency bands in 5G

Low Band: 600-900 MHz, provides deep indoor coverage in urban areas and is suitable for rural coverage. In this band speed and capacity are less and latency is high and is used by legacy technologies and 5G

Lower mid- bands 1.5 GHz - 2.6 GHz, basic capacity layer, used by legacy technologies and 5G

Upper mid bands: 3.5 GHz, 4.8 GHz, 6GHz, city- wide speed coverage layer, used by 5G only

High band (millimetre wave band): 26 GHz, provides high speed and capacity, suitable for super high capacity hot-spots and has low latency but range is less, used by 5G only

WRC (World Radio Communication Conference) - 2023

WRC-23 will be conducted from November 20, 2023 to December 1223 at Dubai. This conference is going to focus on the mid band of the 5G spectrum. DOT is working out our strategy for the meeting by conducting various studies and deliberations. It is fully committed to get additional spectrum for 5G services.

The advantage of mid band for 5G

In the low band coverage is more. In the high band capacity is more. The advantage of mid band is that it is a balance between coverage and capacity.

5G roll out in our country

India has one of the fastest roll out of 5G networks with the roll out of 2.7 lakh 5G sites within 9 months. The roll out will be completed by 23-24. We need more mid band spectrum in 5G as 5G services expand.

Mid band spectrum needs

The vision for 5G is that it should provide the 100 Mbits/sec down link and 50 Mbits/sec up link user experience data rate at anytime, anywhere, while ‘on the move’ . As per studies conducted in 36 cities all over the world, 5G services need 2 GHz band width of mid band spectrum.

Why 2GHZ of mid band spectrum is required for 5G?

1. Densely populated cities need, on an average, a total of 2GHz mid-band spectrum.

2. IMT (International Mobile Telecommunications) 2020 requirements (for 5G networks, devices and services) will be at risk with less spectrum and significantly more base stations would be needed without sufficient spectrum assignments.

3. Additional base stations will generate 1.8-2 times higher carbon footprint.

4. There will be higher demand for Fixed Wireless Access (FWA) for high speed internet services due to high costs involved in laying fibre for FTTH (Fibre to the Home) service). The additional spectrum in mid- bands will allow each cell site to support 3.5 to 6 times more homes with 5G FWA.

The right candidate to source this additional mid band spectrum of 2GHz is 6GHz band.

Features of the 6 GHz band

1. Globally allocated to the mobile service on a primary basis

2. Good balance between coverage and capacity

3. The band is currently underutilised.

4. Can support large contiguous blocks (700 MHz from 6425 to 7125 MHz). Contiguous large blocks give clear benefits. Large bandwidth reduces the cost per bit. A 100 MHz contiguous block is more efficient than 50+ 50 MHz. A large block in one band is more cost efficient than smaller blocks in multiple bands.

5. Existing support gives economies of scale

6. Wide industry support: High priority band for most mobile operators and vendors. 3GPP has started standardisation work in the 6GHz range.

7. Demand driven by Fixed Wireless Access, smart cities and mobile broadband

6GHz band: Cost-benefit analysis

Unlicensed use across the whole 6GHz band was not the most beneficial in any scenario.

The most benefit to society comes from assigning between 700-1200 MHz of 6 GHz spectrum to lienced 5G.

6GHz development principle

Technical barriers: There are no technical barriers in developing and commercialising 6GHz IMT solutions. Device and infrastructure solutions can operate in this band, just like any other band.

Ecosystem readiness: Key players in device component and network infra ecosystem are ready to develop 6GHz IMT products in line with customer demand.

Development triggers: The main trigger for the commencement of product development will be operator demand, driven by WRC-23 and national regulator decisions.

Development timeline From the start of development, players expect that they could have solutions ready in 6 to 12 months.

Roll out timeline: With the development of 6GHz radio, it is inferred that its behaviour is exactly the same as 3.5 GHz radio. By the end of the current decade commercial roll out of the 6GHz network by MNOs will take place. Vendors, chipset manufacturers and operators are showing interest in 6GHz radio. Prototyping and simulation testing were completed in 2021. 3GPP Rel.17 specification for upper band (NR band 104) i.e 6425 MHz-7125 MHz was completed in 2022. IMT specifications of this band will be carried out at WARC 23.

Spectrum Management for 5G Private Networks

Three approaches are followed globally for the spectrum management of 5G private networks:

1. Set aside spectrum: Assigning a range of spectrum to be exclusively licenced to industry users.

2. Spectrum sharing framework: Enabling several users to access spectrum simultaneously. Sharing may be based on geography or time.

3. Licence conditions for public mobile operators: Enabling or requiring mobile operators to deploy private networks or lease spectrum for this purpose.

In different countries different approaches are followed. Among the three approaches, the third approach is considered as the best with respect to efficient use of spectrum, productivity and economic costs. This approach is used in most of the countries (including India and Finland) and it stimulates cooperation between 5G Service Providers and enterprises.

In India deployment of Captive Non Public Networks (CNPNs) by the TSPs using 5G technology has gained momentum. The details are as follows.

1. HPE (Hewlett-Packard Enterprises) and Cisco are in talks with Indian TSPs to deploy private networks

2. Airtel and Tech Mahindra will deploy private 5G network at Mahindra's auto manufacturing unit in Chakan

3. JIO is likely to setup private 5G network for first Tesla factory in India

4. Maruti Suzuki is in talks with TSPs for setting up a 5G smart factory

5. BSNL has tie- ups with TCIL, Amaantya and Echelon Edge for setting up CNPNs. BSNL 5G spectrum will be used for these captive wireless networks and these companies will act as System Integrators.

Way Forward

5G is not evolution but revolution. It will contribute $1 trillion to the global economy by 2030. But if adequate spectrum is not provided, its contribution will be less by 40 per cent. 5G services need more spectrum in mid-band (2 GHZ bandwidth). This additional spectrum required will come mainly from 6GHz. Whatever spectrum the 5G operators have acquired now in India, will not be sufficient by the end of the decade when they expand 5G footprints. Hope more spectrum, especially in the mid band, will be made available to them.

Apart from making more spectrum available for 5G services, efficient 5G technologies should be invented to improve spectral efficiency, that is to pack more data (bits) per unit bandwidth (Hz).

(The author is retired Advisor, Department of Telecommunications (DOT), Government of India)