EDN’s 5G Standards watch begins
The complexity of 5G is such that despite the anticipation of its eventual arrival in 2019 – a year sooner than originally planned – the standards have yet to be formed. This has created a sense of urgency and frantic activity to have a workable standard before the end of 2017 so that IC development can begin in earnest, and systems can be developed in 2018 and deployed in 2019.
That said, there are many 5G-like trial deployments underway globally as operators struggle to balance increasing user demand and the need to be seen as being ahead of the game. Trials help evaluate the ability of their networks to cope, while providing valuable experience and data on what it’ll take to meet 5G requirements. Whatever sharable information is gleaned from these trials also informs the decision-making as to what 5G will eventually comprise, which falls to the Third-Generation Partnership Program (3GPP) (Figure 1).
Figure 1 The 3GPP’s members are global and it breaks down 5G technical developments into three segments: RAN, SA, and CT. (source: Samsung Electronics)
Despite the 3GPP’s long history in developing cellular-type standards, the difficulty of formulating 5G standards arises from the technical goals of 5G itself, as well as the need to consider the concerns of the many stakeholders, and applications beyond classic cellular (3G/4G). These include Wi-Fi, the Internet of Things (IoT), broadcast radio, and of course automotive and autonomous vehicles, and critical communication needs.
The standards’ formulation is also happening at a time of rapid change toward a more abstracted, software-defined core Internet, to accommodate network function virtualization (NFV), greater quality-of-service requirements, and heightened security concerns.
As a result of the overall complexity, the development of standards has been broken into two phases. It is Phase 1 that is scheduled to be defined before the end of 2017 (Figure 2).
Figure 2 Some parts of what will eventually be 5G will be formulated by the end of 2017, as Phase 1. ICs and equipment based on Phase 1 can then begin development, even as work on Phase 2 continues into 2018. (source: Samsung Electronics)
Work on Phase 2 will begin right before then, in late 2017, and will run into 2018. 5G Standards Watch will be detailing the elements of Phase 1 and 2 as they become clearer.
The goals of 5G
Though the standards work continues frenetically, its amorphous state means that in some ways it’s more useful to outline the requirements and goals of 5G, before getting into the state of the standards.
The most obvious goal is increased overall throughput for each user – up to 1 Gbit/s. Of course, the download rate depends upon user density, so for users in a metropolitan area, 5G should be able to deliver hundreds of megabits/s.
The trick is to optimize spectral efficiency such that data rates can be maintained with greater coverage and with thousands of users and IoT nodes connected simultaneously. This spectral efficiency can be improved in many ways, including higher orders of modulation, the use multiuser multiple-input, multiple output (MU-MIMO) antenna arrays on both basestations and handsets, as well as beamforming techniques that ensure maximum throughput on a per-user basis and carrier-aggregation techniques that make maximum use of available bands. With wide swaths of spectrum being assigned to 5G, the ability to pick bands and aggregate them for optimum throughput, while complex, is also a fundamental part of 5G. In the U.S., the FCC in 2016 assigned spectrum in the 28, 37, and 39 GHz (millimeter-wave) bands.
Low latency and smooth handoffs
In the context of IoT and automotive, current 3G and 4G networks generally have latencies of 50 ms. This is insufficient for IoT sensor and actuator nodes that may be monitoring and controlling a critical piece of equipment, including vehicles. The goal of 5G is to get this latency down to 0.5 ms or less (without a high-reliability requirement). With high reliability (being defined as 10-5 for a 32-byte packet), that latency at the user plane rises to 1 ms.
Vehicle-to-vehicle and vehicle-to-infrastructure (V2X) applications need the low-latency promise of 5G, along with smooth transitions for both user handsets and effective machine-to-machine communications. For this, the 3GPP is looking at greater Wi-Fi and cellular network integration for 5G.
Operators like their LTE licensed spectrum as it helps them deliver the best user experience, and to date have used unlicensed LTE spectrum or Wi-Fi networks as an off-load option when cellular networks reach their limits. 5G will support standalone unlicensed access.
However, as with any technical standard, 5G runs the risk of succumbing to mission creep. In the case of 5G, the access network is being asked to also accommodate fixed wireless (such as those used for high-speed backhaul where wired access is not possible or economically feasible), as well as optical networks and even non-terrestrial networks, from drones to airplanes to satellites.
There is much to be done, but in the months and years between now and 5G’s deployments, EDN’s 5G Standards Watch blog will be keeping you up to date on what’s important as the standards and technologies – from the edge to the core – evolve, gel, and evolve again. We will track the 3GPP and well as the work of operators, equipment, and IC vendors as they work to both preempt and add to the standards work. We will also track the global regulatory evolution as governments work to pave the way for the innovation to come. Your suggestions, comments, and insights are welcome.
—Patrick Mannion has a long association with EDN, EE Times, and other publications, and currently leads an independent content engineering firm specializing in technology analysis, editorial & media services.