5G is the next generation of mobile and wireless broadband technology, capable of ultra-fast speeds, low latency and excellent reliability. Spectrum access will be key to bring in the new technology. To deliver affordable, high quality mobile broadband services, operators require fair access to sufficient radio spectrum in a timely manner. “It is something regulators and governments need to get right if they want to be at the forefront of 5G innovation,” says Jawad Abbassi, head of MENA, GSMA.
A multi-layer spectrum approach is required to address the wide range of usage scenarios and requirements of 5G, according to a position paper on 5G Spectrum published by Huawei at the 8th Global Mobile Broadband (MBB) Forum in November, 2017. The "Coverage and Capacity Layer" relies on the 2 to 6 GHz range (e.g. the C-band, 3.3-4.2 and 4.4-5.0 GHz) to deliver the best compromise between capacity and coverage. This layer will emerge as the world's first band for the much anticipated commercial deployment of 5G. The "Coverage Layer" exploits the spectrum below 2 GHz (e.g. 700 MHz) providing wide-area and deep indoor coverage. The "Super Data Layer" relies on the spectrum above 6 GHz (e.g. 24.25-29.5 and 37-43.5 GHz) to address specific use cases requiring extremely large capacity and high data rates.
How significant is spectrum sharing in the way forward? There is significant potential for the coexistence of 5G and other wireless services in higher frequency bands above 24 GHz, says Abbassi. “The sharing studies done ahead of WRC-19 have already highlighted this potential.” Spectrum sharing unlocks more spectrum, unravels new deployment scenarios and increases spectrum utilisation.
According to Huawei, 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.
Recently, Qualcomm Technologies demonstrated advanced 5G technologies for the next phase of the global 5G NR standard being developed by 3GPP. Among the demonstrations, Qualcomm Technologies showcased a live over-the-air demonstration of 5G NR spectrum sharing technologies. The use of 5G spectrum sharing technologies is expected to bring higher levels of mobile broadband performance to unlicensed and shared spectrum, as well as play an important role in extending 5G into new types of deployments such as private networks for industrial IoT.
In addition to access to the right spectrum, something which is equally crucial is how the available spectrum is utilised in the best possible manner. According to Abbassi, the key to effective utilisation of available spectrum is for regulators to develop an investment friendly framework that gives operators the ability to make the most of available spectrum. “For example, the rise in the cost of access to spectrum for mobile operators is a threat to mobile broadband growth – especially 5G. Regulatory certainty is also needed for mobile networks to flourish.”
With Massive MIMO, operators now have a powerful new tool to boost capacity using their existing spectrum. Data from several hundred Massive MIMO commercial test sites shows that the technology increases spectrum efficiency dozens of times, which will in turn allow operators to lease fewer spectrums. Moreover, it almost doubles outdoor coverage. At the pre-MWC briefing in London, Huawei revealed that a full series of scenario-based Massive MIMO AAU (MM AAU) products would be released at the MWC 2018. These products accommodate various 5G deployment scenarios and make operators ready for 5G in advance based on 4G networks. Zhou Yuefeng, Huawei Wireless Network chief marketing officer, said: "Massive MIMO is one of the important air interface technologies of 5G and is the core technology to differentiate 4G and 5G networks. The rational planning and deployment of MM AAUs are crucial.”
Huawei's Massive MIMO products have seen large-scale deployment in over 40 countries, such as Japan, China, Spain, UK, and Saudi Arabia. As early as 2016, Huawei worked with SoftBank to test TDD Massive MIMO and multi-carrier aggregation using the 40 MHz bandwidth on the 3.5 GHz band, achieving a downlink throughput of over 1 Gbps. Meanwhile, performance testing of Huawei FDD Massive MIMO have been conducted on more than 10 commercial networks in countries such as China, Thailand, Turkey, and Kuwait. The network capacity is four to five times higher than that of the live network. It is estimated that Huawei FDD Massive MIMO will begin large-scale commercial deployment in 2018 through to 2019.
Towards the end of 2017, Verizon, Ericsson and Qualcomm Technologies completed a successful FDD Massive MIMO trial with a fully compatible customer device. Niklas Heuveldop, Head of Market Area North America, Ericsson, said: “Advanced Antenna Systems and Massive MIMO are key technology enablers for 5G, and 4G LTE service providers and end users will also benefit from the superior capacity and network performance these technologies enable. The latest trial is another important step in the collaboration we have with Verizon and Qualcomm Technologies to further evolve 4G and prepare the network for 5G.”
Each new generation of mobile technology brings new efficiency, but consumer demand for mobile data is increasing at an amazing rate. So, at the end of the day, significant new widely harmonised mobile spectrum is needed to ensure services meet future expectations and deliver the full range capabilities, Abbasi notes.
According to Huawei, a globally harmonised spectrum framework for 5G will enable economies of scale, facilitating cross-border coordination and roaming for end users. “Consistent spectrum release timelines and harmonisation measures are key enablers for the success of 5G.
Licences offering exclusive use of nationally available bandwidth remain the main and preferred authorisation model for accessing 5G spectrum, bringing certainty for investments, predictable network performance and quality for end-user connectivity.”
Since IMT networks are providing the platform to serve a growing number of vertical industries, Huawei believes regulations should not add constraints to the introduction of such platforms (e.g. NB-IoT, C-V2X, IMT for trunking and PPDR, etc.). “Regulators should also consider facilitating forward-looking strategies to support the convergence between TV broadcasting networks and IMT systems.”
And then, success isn’t just about allocating new spectrum bands. The GSMA calls on governments and regulators to prioritise mobile broadband services – above revenue maximisation – when awarding new frequencies. High spectrum prices threaten affordable, high quality mobile broadband services whether for 5G or other generations.