Before long, 5G will be in the early stages of commercial reality. From a technology perspective, 5G is adding significant complexity for operators: more spectrum, more frequency bands and more transmission points, while providing new services and serving new markets. And there is significant commercial pressure to have 5G available as early as possible.

A recent survey and report conducted by the Telecommunications Industry Association (TIA), in conjunction with Tolaga Research and InterDigitial, outlined a number of key network operator concerns and how they plan to address various aspects of 5G. Upon review of this research, the following six issues emerge as those that are worth following closely. These issues, and how they play out over the next few years, will influence a considerable amount of the future of 5G.

Trials, testing and deployment

Looking back to an earlier generation of wireless technology, a 4G Radio Access Network (RAN) could only connect to a 4G core network. It had to operate as a stand alone network, separate from the 3G networks it was replacing. However, the transition to 5G will be different because the 5G RAN can be deployed (in early phases at least) within an evolved 4G network. This will speed up testing and trials of the RAN side of the network, in particular. Standalone 5G networks will definitely happen eventually, but, in early phases, 5G New Radio can be deployed as assistive technology to existing 4G networks. This will help operators spread their infrastructure investment out over time, which is an attractive quality considering the scale and scope expected for full-scale 5G deployments. In addition, data and experience from the trials and testing can be used to help inform deployment decisions and save resources for other more costly aspects of 5G network operations in the long run.

Global rollouts

There will be a lot of competitive pressure to demonstrate both capability and feasibility in the early, pre-standard phases of the 5G technology cycle. Some of this will be on display (in limited ways) as early as next year at the South Korean Winter Olympics. Other major sporting events in the next several years (2018 Australian Commonwealth Games, and the 2020 Summer Olympics in Japan) will serve as test-beds for 5G demonstrations and small-scale deployments. Testing at these sporting events will demonstrate to the international community some of the real-world capabilities of the 5G technology. It’s likely that some first-mover advantage may go to those regions where these early pre-standard deployments take place, simply because those operators will be among the world’s first to work with large-scale, live deployments outside a laboratory setting.

Spectrum issues

There are three main parts to this topic, which are all interrelated.

First, there’s some uncertainty about how to exploit new frequency bands (particularly at higher frequencies), which is a big issue that will be addressed with technology. Most deployments will certainly utilize spectrum below 6 Ghz, where traditional operators are familiar with the technical issues, and where they know how network propagation works. But 5G networks will also exploit spectrum above 6 Ghz — up into the 25-50 GHz range, and in some cases even beyond that. There are significant challenges at those frequency ranges, and existing mobile operators have limited experience working in them.

Second, there will naturally be differences in regional spectrum assignments and auctions that may occur. We will likely see inconsistencies across different regions, and the need to support different frequency bands and band combinations will ultimately impact device complexity and cost.

Finally, the opportunistic use of unlicensed spectrum is seen as an attractive means by operators to boost their capacity beyond licensed spectrum in order to meet the 5G data needs. The extra capacity, however, does come with its own set of new challenges, such as co-existence with others, and operators will need to learn how to integrate and optimize the unlicensed spectrum in their 5G networks.

Network densification and small cells

Using higher frequency bands means more density is required in the network – more transmission points, more basestations, and smaller cells— which will add significant requirements especially for transport and backhaul networks. The backhaul and transport issues created by this level of network densification will become a significant challenge, not only from a technology standpoint, but from a business standpoint as well.

On the technology side, the optimal approach is to have highly capable fiber optic backhaul connections in order to achieve the best results in terms of bandwidth, latency, and reliability. But in many cases, it may be more practical, cost effective or even necessary to use wireless technologies such as millimeter wave as backhaul solutions. On the business side, operators will have to find more partners — building owners, municipal governments, utility companies — to allow them to deploy these increasingly dense networks.

Use cases

Thus far, many use cases have gotten a great deal of the press coverage around 5G. In early phases of 5G, several of these use cases will be the most likely to emerge: enhanced mobile broadband, connected vehicles, sports/fitness wearables, smart cities, and the like. These use cases will be introduced over time, as customer demand grows. Their propagation will vary somewhat depending on the needs of the particular operator, region, and user base. Some will move more quickly than others due to external factors like demand, user density, and regulations. Others will take more time to come to maturity. It will be important for network operators to be closely attuned to the needs and desires of their customers and to address the capabilities of their networks accordingly.

Network slicing and virtualization

5G networks are going to be more complex than the 4G and 3G networks that preceded them, for all the reasons we’ve listed above, and more. This means that one of the key challenges for operators is going to be making sure their network is always optimized while running smoothly and cost effectively. There are some different network slicing and virtualization technologies coming into play in this area, which will give operators a lot more flexibility in terms of running their core networks more efficiently. The process of network slicing is very attractive in this context because it allows the operators to be far more flexible in allocating resources to different services as needs change over time. Rather than dedicated resources going to a specific service in a more traditional “hardware” approach, a virtualized and sliced “software-defined” network can scale up and down dynamically. This will be one of the most important aspects differentiating next-generation core networks.

While there is much industry focus around 5G, these issues show that there still remains a broad, and sometimes diverging, range of opinions and strategies amongst different operators when it comes to 5G. The one thing that seems clear across the board, however, is the overall excitement towards 5G and its potential opportunities. For operators to make the 5G dream a reality, addressing these issues will be key before 5G’s rollout in 2020.

 

Chris Cave is Director of R&D at InterDigital, a mobile technology research and development company that provides wireless technologies for mobile devices, networks, and services worldwide.