The role of mmWave in 5G backhaul solutions

2nd March 2021 by Neill Young

As 5G rollouts intensify, backhaul innovation is becoming a crucial way to support the higher bandwidth, denser networks and low latency applications expected of 5G in both public and private networks.

In the past, as bandwidth has increased with successive generations of mobile networks, backhaul has had to keep pace and overcome the major challenges of availability, capacity, cost, and reach. Now, as 5G network capabilities and services are rolled out, backhaul faces two additional challenges: meeting low latency requirements for advanced applications and the ultra-dense nature of the network.

5G backhaul will naturally need to support hundreds of gigabits of traffic to and from the core network. Current backhaul, designed for previous generations of mobile technology is likely to struggle to meet the capacity, availability, latency, and cost-efficiency requirements, and so new innovation is needed.

A wireless backhaul solution

Now more than ever, a wireless solution will be the obvious choice for backhaul. The traditional bands for wireless backhaul between 6 GHz and 42 GHz served well for 4G but they will struggle to meet the higher data rates and increased capacity of 5G. One way to overcome the additional backhaul bandwidth challenges is to move higher up the spectrum into mmWave bands – the 14 GHz available between 57 GHz and 71 GHz are particularly well suited for this.

For backhaul requirements, mmWave equipment is ideally suited because of its capability and ease of deployment. Instead of digging up roads to create trenches for fibre optic cables, which can be expensive, take a long time to complete and are often bad for the environment, mmWave small cells can be easily mounted on existing infrastructure.

To create the coverage and bandwidth one would expect from a 5G network, small cell base stations can be placed throughout a city on lamp posts, in buildings or even on public transport.

In complex urban environments, it can often be impossible to lay new fibre exactly where it is needed without causing disruption, so compromises in the position of these small cells have to be made. Wireless nodes can often be placed at the best locations without having to compromise, meaning that with smart network planning the coverage and throughput results the network needs for the applications it supports will be much more easily achieved.

Overcoming challenges

As well as having to meet high expectations around performance, there are other perceived challenges of 5G backhaul:

  • Transmitting data at speed: The low latency of fibre networks to transmit data back and forth at pace, without delay, will need to be matched. High-performance mmWave easily meets that quality of service for users and can further improve their experiences.
  • Security: Another challenge is ensuring safe and secure transfer of data between points. Low-latency, highly secure wireless backhaul is already commonly used in today’s public safety and utility networks. The use of low-latency transmission technology and encryption means that wireless transmission can be more secure and reliable than fibre, with an additional benefit being that it cannot be unintentionally damaged by building works or extreme weather events.
  • Reach: Deploying networks of any kind is more difficult in rural areas where connection points have greater distances in between them. That being said, mmWave small cells are able to connect over long distances and so can be deployed wherever and whenever, and their flexibility means they can be installed over much greater areas with less expense and less disruption than fibre.

Benefits of mmWave for backhaul

Keeping the backhaul network completely separate from customer facing networks means that network operators are able to maximise their return on investments in both spectrum and network infrastructure. Expensive licenced spectrum is best reserved solely for customer access, and not relied upon for integrated backhaul. It makes little economic sense to use expensive licensed spectrum for both backhaul and customer access as network performance will be compromised leading to potentially poor returns on investment.

Instead, operators should consider taking advantage of the unlicensed spectrum for backhaul requirements. There is no cost for using the spectrum, and technologically mmWave will provide higher bandwidth and lower latency for backhaul – a win win. In turn this means that the licenced spectrum can be reserved exclusively for those all-important customer devices, rather than competing with backhaul for resources, to ensure excellent performance.

Additionally, in a typical 5G network deployment, there will likely be multiple small cells over a wide area to increase network capacity. Some of these small cells may be a considerable distance from the control point, and having high bandwidth wireless backhaul in place means that congestion on the network is much less likely to occur, particularly as data from different sites is aggregated together. Utilising integrated backhaul means that congestion and thus poorer overall network performance is much more likely.

Taking these factors into consideration, mmWave wireless technology provides the optimum solution to meet the increasing demands for 5G and next-generation communications.

If you are interested in learning more about our high bandwidth, multi-gigabit 5G networking equipment and how mmWave technology can be applied to meet your connectivity needs, get in touch with us today.