PARTNER INTERVIEW: Ahead of MWC19 Los Angeles, Mobile World Live (MWL) caught up with experts from Ceragon Networks to discover how operators can adapt their infrastructure to provide the ultimate 5G experience.

MWL: What fronthaul, midhaul and backhaul challenges does 5G provide for operators compared to previous network technologies and how can these be best addressed?
Ceragon Networks (CN): While previous generations of mobile network technology represented single steps forward, 5G signifies multiple moves in several directions simultaneously and provides significant operational and technical challenges.

Advanced applications including VR, AR, industrial IoT, consumer IoT and smart city deployments will need improved reliability, reduced latency, and massive jumps on data rates compared to even advanced LTE networks. They will need to be light-years ahead of standards delivered by 3G.

But how can operators provide the almost limitless connectivity, high reliability and low latency required to supply these services? The answer starts with adopting the right network architecture and the latest backhaul, midhaul and fronthaul systems.

Capacity requirements are likely to be up to 100-times higher than in previous network technologies, requiring massive network densification efforts. 5G RAN, 5G backhaul and 5G core must all be designed to live up to the promise of the ultimate mobile experience.

To do this 5G networks must utilize new frequency bands, wider channels and advanced capacity-boosting technologies.

Fresh mindset
Backhaul infrastructure in modern networks will be required to connect a greater number of sites with higher capacity while accommodating macro-cells, small-cells, cloud-RAN and distributed RAN topologies.

Traditional wireless backhaul solutions, which combine a radio unit with a networking unit, have a severe flexibility issue as they cannot be broken down into independent components. This gives them little chance of meeting the demands of an advanced 5G network.

To deliver the required capacity, a functional split between the baseband and radio will be needed, with the division of a baseband unit into elements comprising a: Control Unit, Data Unit and Radio Unit. This will facilitate virtualization and reduce capacity requirements placed on the fronthaul. It also adds a new level of flexibility into operator networks.

Further complicating matters, many of the most demanding and critical functions will need to be performed in dense urban areas, regions where deploying infrastructure has always proved challenging.

To meet these requirements quickly and cost efficiently, radio units should be connected primarily using wireless technology in the smallest possible footprint. This limits the need to access fiber and cuts red tape.

Which technologies can operators utilize to ensure they make the most of their 5G spectrum assets?
Massive MIMO has been the talk of the industry for some time, but in 5G it is a cornerstone technology, which provides a vast improvement in operator use of spectrum assets. This, together with advancements brought by use of 5G New Radio standards, already provides spectrum efficiency improvements compared to technologies used previously.

In addition to adopting updated network architecture and innovations such as multicore technology, operators can enhance their use of existing assets through operational advances including the use of the latest automation and service orchestration technology.

These features will allow effective maintenance and open the way for the use of techniques such as network slicing and segment routing.

What are the key considerations in the design of wireless backhaul strategies for 5G networks?
By focusing on the use of wireless technologies rather than reliance on access to high capacity fiber, operators can increase the pace of rollout while keeping costs in check.

The massive increase in capacity needed for 5G applications not only requires technological innovation but a greater number of physical sites – the acquisition of which can be a problematic and expensive headache.

By selecting the most appropriate solutions, though, operators can drastically reduce time to market. One example of how operators can ease deployment issues is by selecting all-outdoor wireless backhaul systems rather than split mount configurations.

Outdoor units
An all-outdoor wireless backhaul unit can cut the time for deployment of new sites in half by eliminating the need for indoor rack space. The lack of a need for shelter makes site allocation and acquisition simpler, faster and more cost-effective.

With the node covering both radio and networking in a single box there are fewer parts. Having no indoor elements also eliminates the need for power consumption associated with cooling and air conditioning units seen in split configurations, leading to significant Opex savings.

Addition of modern multicore technology into these units can also offer multicarrier connectivity in a single box, increasing capacity in an easily upgradable solution.

Many applications cited as key 5G services require extremely low latency and high bandwidth, what are the main considerations to ensure these use cases deliver on expectation?
Automation, service orchestration techniques such as network slicing and the adoption of innovations such as Multiaccess Edge Computing will aid operators in meeting the specific expectations of many verticals frequently cited as 5G opportunities.

By being able to segment and open parts of the network, operators are able to serve the needs of specific sectors, with some relying on high capacity and others on low latency, without necessarily needing both.

5G, in many cases, will require the coexistence of multiple services over the same network. Each service will need to be guaranteed at a defined minimum quality regardless of the status of other uses of the network. Achieving this will need comprehensive service orchestration measures and techniques like network slicing and segment routing.

What is the potential of new frequency bands to deliver the huge capacity requirements expected of 5G technology?
Various countries are already beginning the processes of opening-up bands above E-band for wireless technologies. These will allow rapid increases on the 20Gb/s able to be achieved over the air on E band.

To enable operators to take full advantage of these developments infrastructure companies including Ceragon Networks are already working on techniques to use these frequencies to deliver speeds of 100Gb/s or more.

As W-band and D-band are opened-up, operators will be able to potentially access higher rates and increase their business opportunities into vertical sectors with a higher requirement than currently available.

When regulators begin allowing use of these ultra-high frequency bands, operators that have adopted easily upgradable and advanced infrastructure will be the ones best placed to take full advantage.