How 5G supports current Telco Business Models
f you’re following 5G developments you’ll be interested in this overview of how 5G helps to effectively deliver ever-increasing amounts of capacity in support of current and evolving telco business models.
Telcos face significant financial challenges in delivering huge amounts of additional capacity across their networks. This is however a fundamental and ongoing requirement that enables their primary business models. The way in which capacity can be increased is effectively limited to four options:
- Increase the number of base stations
- Increase the spectrum deployed on those base stations
- Use the spectrum / radio resources more efficiently / effectively
- Offload onto technologies like WiFi or Fixed Access
Option 1 is costly but fully under the control of the telco. Options 2-4 are all better choices financially but require wider industry development in order to be available for individual telcos.
With 4G, capacity can be deployed very efficiently within relatively narrow bands of licenced UHF spectrum, but “more data to more users, means more base stations”. 5G changes that equation dramatically, bringing the necessary industry development to realistically enable options 2-4, and even optimise option 1!
Firstly, in large cities and towns customers are now usually much closer to the existing base stations than they were previously. Secondly, a well-planned and relatively high capacity 4G network generally already exists, with good coverage and high reliability. This means we can deploy 5G very differently to how we deployed 4G.
4G was designed to support a “worst-case” scenario of a relatively large cell in an urban area. Here the radio environment is very difficult but the configuration of the radio interface minimised interference issues. However that configuration in turn limited us to the parts of the spectrum currently used for LTE (~700MHz – 2.6GHz).
Bring on 5G …
5G - ACCESS TO MORE SPECTRUM
For 5G we have been much more flexible. Different radio interface configurations, or numerologies, allow for optimal support for a much wider range of cell types and frequencies. This includes lower spectrum bands at 700Mhz, right the way up to millimetre wave bands, in Europe ~ 26GHz.
This means we can deploy 5G in much the same way as LTE, or make use of much higher frequencies in support of smaller cells. At higher frequencies, there is a LOT of additional spectrum available.
Additionally, because high-frequency cells are small they can be deployed as part of a full-coverage multi-frequency, layered architecture. Any high frequency 5G cells can be deployed in support of isolated pockets of high-capacity. Isolation means interference between cells is minimised and telcos and operators can realistically share huge chunks of unlicensed spectrum.
And don’t forget we still have 4G, so we don’t need to provide full coverage with 5G so long as we ensure 4G and 5G work together.
5G - GREATER EFFICIENCY
Higher frequencies require smaller antennas. This means we need to use antenna arrays rather than just single antennas in order to effectively transmit or receive enough energy to operate. In fact, at millimetre wave frequencies, or even at mid-band (3.4GHz – 3.8GHz), very large antenna arrays are feasible; 64Transmit / 64Receive are already deployed, and 256 are feasible.
It is the antenna arrays, when used with advanced antenna techniques, that give us much of the additional spectral efficiency. Using constructive and destructive interference, antennas can beam-form or build a bubble of energy around a mobile device, in both cases significantly increasing the efficiency.
5G - OFFLOADING
Offloading is also a focus of 5G and made possible by much tighter integration of non-3GPP technology, e.g. Wi-Fi or Fixed Access, not least in terms of security. Mobile devices can be directed by the cellular 5G, or 4G, network to select and connect via an alternative access method.
In 5G this is potentially feasible even in roaming scenarios and as part of a public network. There are some mechanisms already standardised to allow this to happen, but a lot of work still needs to be done if this is to go mainstream.
5G - DEPLOYING MORE BASE STATIONS
Even if we are still required to deploy more base stations, which we are, 5G also helps with this part of the equation. At lower frequencies, co-location with 4G is very much feasible and the preferred option. This is effectively a way of using 5G spectrum to boost a base station with additional 5G-allocated spectrum.
For high-frequency millimetre wave, small-cell deployments, the picture changes. Small base stations can be deployed in line of site of larger macro-cellular base stations. They will self-backhaul using part of the cellular spectrum to connect directly to the macro-cell site, and then through any existing fibre to the core of the network.
Optionally, small cells may also be made up of distributed radio units that have a centralised processing unit co-located with the macro-cell. This is a feature that has been standardised with 5G.
Both of these features minimise functionality in the small-cell “distributed units” and enable rapid and cost-effective small cell deployment.
So, as you can see, 5G helps to successfully deliver progressive amounts of capacity in support of both current and evolving telco business models. It will require initial investment but in the long-run the capacity equation in 5G is no longer overwhelmingly about the number of base stations.
This article is the first in a series of how 5G supports new and evolving business models. As you may realise, some concepts have been very much simplified, details have been omitted, I’ve ignored 2G and 3G and said nothing of how 5G can also support new use cases and new business models – I’ll leave that to another time!