Opinion: The RF Path to 5G

The rise of smart devices is largely what drove the wireless operators’ rapid implementation of 4G LTE networks in many regions. Dealing with the demand for data has been central to mobile operators’ strategies over the last number of years, they have worked not only to provide data-hungry subscribers with the bandwidth they need, but also to guard the profit margins demanded by their shareholders.

5G is being talked about in much the same way that 4G was in the second part of the 2000s. As such, players across the wireless industry are now moving forward in attempts to influence and define what 5G will be. Fundamental technical definitions of 5G are emerging amidst thoughts about what it will need to deliver.

M2M connections will add to the data load put onto wireless networks, and will further push the need for more capacity.

The rollout of any new generation of mobile network is never as simple as flicking a switch. While much of the current discussion around 5G is about its definition, the fact of the matter is that it cannot happen until plans are in place for how it can happen in the network. Like all grand designs, obstacles need to be overcome in order to arrive at the desired end point.

Like others, CommScope’s fundamental viewpoint in regards to 5G is that it will be a “network of networks.” The ongoing cell densification involving macro sites, indoor areas, metro cells and small cells must continue in order to deliver 5G speeds and capacity, however they get defined. This densification adds ever more complexity to wireless networks and demands ever more sophisticated infrastructure solutions.

5G will require adding more spectrum which must be accounted for in the network equipment that will also support existing 3G and 4G networks. Managing multiple frequency bands in shared site equipment is an art form in itself. New access network techniques such as Massive MIMO are required to deliver a 5G experience. Sophisticated RF beamforming and interference mitigation technologies will need to be developed to achieve the goals of 5G.

Advanced self-organizing network (SON) capabilities in addition to core network architecture changes will be needed. The new core network architecture will take advantage of new networking paradigms such as Network Function Virtualization (NFV) and Software Defined Networking (SDN). Operators will utilize these and powerful analytic tools for the core network in order to automatically optimize their networks.

5G is often linked together in conversation with the concept of the Internet of Things (IoT). In the IoT concept, a multitude of sensors, meters and other machines will connect wirelessly to the Internet to create more value and efficiency across a host of applications. These machine to machine (M2M) connections will add to the data load put onto wireless networks, and will further push the need for more capacity.

Fundamental technical definitions of 5G are emerging amidst thoughts about what it will need to deliver.

An open question regarding IoT networks will be how much capacity these connected things require. It is unlikely that connected parking meters will hog as much bandwidth as a person streaming video wirelessly, for example. Current scenarios for IoT applications are mostly connection-oriented, which will not drive a lot of data, but some of them will affect latency requirements.

For example, the collision avoidance systems in connected automobiles are a driver for one millisecond latency. Who knows what other applications will come along to drive bandwidth needs in addition to lower latency? The exact network use cases for the IoT will need to be defined in order to finalize the 5G architectural requirements.

If 5G is really going to deliver speeds that are up to 1,000 times faster than the 4G we use today, it needs to utilize the spectrum it will travel over more effectively. Like the journeys to 3G and 4G, the RF path will be critical to the arrival at ‘Destination 5G,’ as will be the need for a high signal-to-noise ratio (SNR) to ensure a robust data service. This ratio has become increasingly important as the demands for high speed data increase.

New multi-antenna technologies, such as Massive MIMO systems, are considered the most likely candidates to improve spectral efficiency in 5G networks. Implementing MIMO with large scale antenna arrays, typically with 64 or more transceiver elements, is expected to increase the capacity of a cell well beyond what is achievable today. Large scale antenna systems become more practical in terms of size at higher frequencies, where the wavelengths become shorter. These antennas are likely to be an important technology in spectrum bands above 2GHz and in TDD spectrum where handset feedback is not needed.

As with each of the G’s before it, no one can say with certainty what 5G will be until it is defined and standardized by the ITU-Telecommunication Standardization Sector. One thing is for certain, and has also been proven by cellular history, when it is established as a standard we will be ready to exploit whatever it enables us to produce, deliver and consume. We’re excited by the possibilities of what this could entail.