November 10, 2016
I noted a few observations while attending the Oct. 4, 2016, 5G Americas Analyst Forum in Addison, Texas, where carriers, including AT&T Mobility, T-Mobile USA and Sprint, engaged industry analysts on many 5G topics.
For context, the industry remains fixated on capacity: how to scale to support 11 GB in 2019 from 4 GB monthly usage. This is fueling the drive toward millimeter-wave communications, which has become synonymous with 5G. (Millimeter wave denotes frequencies above 30 GHz. However, the term became common to use for microwave spectrum in the 28 GHz band, or even for any spectrum above 6 GHz.) Although the access network remains the focus, this is taking away attention from other, more important issues, not the least of which are the use cases and applications that will generate revenue. This could lead to future disappointments; that is, the access network for 5G will be late in coming.
Long Life for LTE
A few reasons lead me to this conclusion. First, LTE and its evolution have a long life, as mobile network operators have stated. We can safely say that LTE will be around 15 years from now, if not even longer. This gives LTE deployments a 20-year life cycle, which is reasonable to expect, considering the success LTE has achieved.
The improvement in spectral efficiency that 5G will bring in sub-6-GHz bands is not substantial enough to warrant a rip-and-replace strategy. Most sub-6-GHz spectrum will use LTE, leaving little room for nascent 5G technology to take hold in that spectrum. 5G’s peak capacity enhancement is attained primarily though carrier aggregation that LTE supports and through antenna multiplicity that will have limited applicability in sub-6-GHz bands.
LTE has been making good strides in reducing latency (only a few x’s from 5G requirements). The improvements 5G bring are embedded deeper into the standard and focus on optimizing features and functions available in LTE. In other words, 5G will have no business case in sub-6-GHz bands in the near future.
Second, two critical aspects are underestimated in millimeter-wave access: devices and transport. The first aspect would flesh out the true use case of 5G: Is it mobile or fixed? Is it for indoor or outdoor deployments? (If it is for fixed applications, even if it is anchored by a mobile network, why should it be called 5G?)
Embedding millimeter-wave technologies into mobile devices is no simple feat, especially considering the antenna requirements necessary to achieve range. Requirements for outdoor access are technically challenging. There are differing views on channel stability and performance that affect service as well as the planning and deployment of millimeter-wave sites — an aspect that’s largely been ignored. Additionally, the ecosystem that’s required to drive down the cost of millimeter-wave deployments will be missing. Markets expressing interest in millimeter-wave technology — the United States, Japan and Korea — are not harmonized and alone are unlikely to generate sufficient scale to achieve necessary cost targets. (Could there be a case to roll 802.11ad, a 60-GHz short-range Wi-Fi, into 5G?). Interestingly, vendors who see access infrastructure capex spending slowing down will be keen to have millimeter-wave base station for carriers to test, but investment on silicon for devices will need much justification. This is a space to watch in the future.
5G Carrier Panel
In relation to the transport network, this issue transcends meeting the performance requirements of the access network to include design characteristics and architecture of the transport network. Fiber will be required for millimeter-wave transport, which means access nodes will have limited deployments to where fiber-optic cable access exists (the same issue as that of small cells). Designing for peak capacity, as is the practice today, will result in high asset underutilization. As a result, 5G will be expensive to plan and deploy in parts of the network that traditionally assume most capital expenditures: devices, access and transport.
The evolution of 5G is one on a long road that will have many twists, turns and unexpected results. There are even greater issues, mainly focused on the business models of carriers, that will need to adapt to 5G. All these elements make 5G unlike any of the previous technologies.
Frank Rayal, is a partner at Xona Partners, a boutique advisory firm specialized in telecom, media and technology, and a market development expert and technologist with more than two decades of experience working with wireless ecosystem players. Visit www.frankrayal.com.