Spectrum management and regulations have a direct impact on 5G commercialization and service provision.
Given the large-scale investment in new nationwide networks that is required for 5G, there is still a need for operators to have exclusive access to spectrum for 5G, as has been the case for 3G and 4G. This is of critical importance to avoid undermining investment certainty due to the lack of guarantee concerning spectrum quality which will inevitably translate into unpredictable quality of experience for end users.
At the same time appropriate incentives, including reasonable spectrum pricing, will play a fundamental role in maintaining the flourishing development trend in the mobile industry while promoting rapid 5G deployment.
Spectrum assignment for specific mobile technologies (e.g. 2G, 3G and 4G), and in some countries for specific services (e.g. voice, data, broadband access), can no longer keep up with the speed of market demand for new network capabilities and for new services with enhanced performance.
The principle of service and technology neutrality is a best practice that has been followed by many countries, including the most advanced markets. Such an approach has allowed operators to swiftly respond to the changes in market demands with tangible benefits for end users.
The 5G duplexing mode will develop towards more flexibility to provide the 5G network with better adaption to service requirements from the spectrum perspective.
5G networks and devices will embrace many new features, exploiting the latest technical innovations. Some innovations provide an opportunity for regulators to adjust regulations for more efficient and flexible spectrum utilisation.
An important feature of the 3GPP Release 15 standard resides in the ability for LTE and 5G-NR to co-exist and share the same low frequency bands without having to fully free those bands from LTE use. In the initial stage of 5G deployment, the new bands likely to be made available for 5G are higher in frequency (e.g. C-band) and support less sub-frames for uplink than most existing 2G/3G/4G bands. Such bands will therefore have more uplink coverage limitations compared to existing bands.
With the uplink spectrum sharing between LTE and 5G-NR, transmissions across 5G-NR uplinks and downlinks can occur at higher frequency bands (e.g. C-band), while the 5G-NR uplink can also exploit spectrum resources in lower frequency bands that the operator has been using for LTE (e.g. 700, 800, 900, 1800 and 2100 MHz). This scheme allows improved uplink coverage at higher frequencies leading to a considerably faster and more cost efficient 5G-NR deployment with more efficient and flexible use of all spectrum assets.
Massive MIMO is a key 5G feature which uses the beamforming technique to focus signals on each user, thereby increasing data rates, and reducing interference. It adopts large-scale antenna arrays that can control the width and tilt, both vertical and horizontal, for 3D beamforming. With the application of massive MIMO, regulatory masks should be revised to support the statistical nature of massive MIMO antenna systems, and spectrum regulation management should be enhanced taking into account time, spatial and direction domains.
Network synchronisation has been successfully implemented in 4G TDD networks ensuring efficient use of spectrum resources by avoiding guard bands between operators’ assignments. Similarly, inter-operator synchronisation and alignment of uplink/downlink transmissions (slot and frame synchronization) is also necessary for efficient deployment of 5G-NR networks in unpaired assignments. Therefore, regulation should facilitate the potential for networks’ synchronization in 5G to make the best use of the valuable spectrum resources.
Duplex flexibility is another important feature in 3GPP 5G standardisation providing flexible and dynamic use of paired and unpaired frequencies. The duplex flexibility will allow smooth adaptation to the service requirements by allowing the DL spectrum resource to be used for UL transmission and vice versa. The general concept of this fully flexible radio interface design will be introduced in 3GPP Release 15 specifications. The related band definition is likely to be part of Release 16 specifications.
Given the expected regulatory implications, the analysis at regulatory side should start in the near future in order to prepare regulatory frameworks when the duplex flexibility feature becomes available.
.In those cases where the incumbent services may not be cleared or migrated to other frequency bands, least restrictive provisions should be added to ensure sharing and coexistence.