PARTNER FEATURE: Year 2020 marks the acceleration of 5G rollout on much larger scales in many more countries, more and more operators are sought for the fastest way of 5G deployment based on spectrum used by legacy technologies. Operators want to make the best use of the performance characteristics of each band to attune with their business strategy while coexistence with all the technologies of legacy spectrum deployed in the network. 5G can definitely benefit from leveraging much higher frequency bands with larger bandwidth, like band n78 or even mmWave bands, than 4G, but it is not always necessarily the fastest way and/or the most cost-efficient way to deploy 5G in the initial stage on a large scale. It is therefore reasonable and sometimes optimal for 5G to utilize sub3GHz bands which are already in use by 2G, 3G and 4G. Spectrum re-farming from FDD to 5G is obvious an easy option but not the best option due to the light load of 5G initial stage. To ensure legacy users’ voice service experience, a dedicated bandwidth is required to be reserved for 2G or 3G, which will not make the best use of spectrum. How to make full use of spectrum with fast 5G deployment and offer legacy UE’s voice service experience in an efficient way is a challenge posed to global operators, and that’s exactly why ZTE SuperDSS comes into being, which enables triple-RAT dynamic spectrum sharing within a carrier within limited FDD spectrum.

What’s SuperDSS?

SuperDSS is the industry unique 2G/4G/5G and 3G/4G/5G DSS (Dynamic Spectrum Sharing) solution, enabling quick 5G roll-out while offering smooth transition of legacy voice service over one same carrier, maximizing the spectrum return on investment. It is also the unique innovative spectrum sharing solution of Magic Radio Pro in 5G era when enabling 5G with legacy FDD spectrum.

Taking 20MHz bandwidth at 2.1GHz band as an example, without SuperDSS, the operator would have to allocate 5MHz for UMTS to provide legacy 3G voice service, 10MHz for FDD LTE and another 5MHz spectrum to 5G as there will only be a minimal number of 5G users at the initial stage of 5G. Even 4/5G DSS is introduced, 4G/5G DSS can only be performed in 15MHz bandwidth rather than 20MHz as 5MHz is used to meet the requirement of 3G users’ voice service. While with ZTE SuperDSS, 3G, 4G and 5G can share all of the 20MHz bandwidth dynamically, and the UMTS bandwidth can be adjusted according to service requirements, which helps operator to deploy 5G and maintain legacy UE’s voice service experience in a fast and agile way.

SuperDSS implements simultaneous 2G or 3G, 4G and 5G dynamic sharing in the same band, that is, 2G or 3G occupies bandwidth based on traffic load, the left bandwidth can be shared by 4G and 5G with delicate scheduling algorithm to avoid clashing of each other. In each millisecond, based on the understanding and analysis of 4G and 5G control channels characteristic, these control channels can be scheduled in such a smart way to achieve minimum interference to each other, whereas 4G and 5G service channels are allocated based on frequency division method, consequently, 4G and 5G required resource will be adjusted to adapt an optimal performance with less spectrum waste, higher ROI of spectrum and better user experience with available 5G services and legacy UE’s voice service experience.

Why SuperDSS?

The first 5G launch in market is with no doubt important for operators as first launch means first wave 5G users market share and higher user stickiness while involving in the first round competition and maintaining legacy UE’s voice service experience simultaneously are also of great importance, as there are still a lot of subscribers who use voice services with legacy GSM and/or UMTS terminals. This is what is going on in the field network every day. It requires the operators to keep at least one UMTS carrier or GSM frequency to guarantee legacy service user experience, so it would not be an optimal way of spectrum utilization to enable just 4G and 5G DSS without any offering of capacity for 2G and/or 3G.

ZTE’s unique SuperDSS supports 2G/4G/5G or 3G/4G/5G full dynamic sharing at the same time over 1800MHz or 2100MHz band, for use of spectrum also by 2G or 3G on demand while giving as many spectrum resources as possible for LTE and NR, which offers both legacy UE’s voice service and 5G service with optimal balance.

In Asia market, the auction of new spectrum, such as n78 just started in some areas. The fastest and best way to have the first 5G launch is to take use of legacy FDD spectrum, while these bands are generally carrying 2G or 3G voice service. With SuperDSS, 5G can be enabled on legacy FDD spectrum without additional spectrum introduction cost, and simultaneously legacy UE’s voice services experience are guaranteed.

In Europe market, 5G network coverage is operators’ common concern as it is hard to provide a continuous coverage at the initial 5G deployment stage, and in some markets, 2G or 3G is difficult to be shut down due to legacy voice service, so SuperDSS can not only empower 5G users a continuous user experience based on legacy FDD network but also taking care of legacy UE’s voice service experience.

Powerful SuperDSS Shaping Future Network

ZTE Magic Radio Pro solution is the industry’s most comprehensive multi-RAT dynamic spectrum sharing solution, supporting up to seven scenarios with five radio technologies (GSM, UMTS, LTE, NB-IoT and NR). As a leader of innovation in this field, ZTE has accumulated rich experiences in multi-RAT dynamic spectrum sharing since 2014, with the development of 5G, ZTE further explores the spectrum sharing possibilities and capabilities with SuperDSS. Based on global success cases of spectrum sharing among FDD modes, ZTE is able to help operators to improve user experience and market competitiveness, offer a fast transition solution from 4G to 5G with guaranteed legacy UE’s voice service experience and optimize TCO with improved spectrum ROI.

With AI technology on the way, AI based scheduling mechanism can further facilitate network performance and user experience together with SuperDSS dynamic spectrum sharing scenario in the future.