Establishing an interim, non-standalone mode for 5G New Radio (NSA 5GNR) has helped ensure that the communications industry is working toward a single, global standard for 5G. By anchoring 5GNR implementations to LTE for the control plane and core network, operator trials and early commercial deployments can take place within a future-proof standards framework.
While not immediately apparent, there are also benefits from NSA 5GNR for operators planning to launch 5G from 2020 onward, although Ovum has not found any evidence that those operators are rushing to bring forward their launch schedules. In the medium term, only standalone 5G can support the full range of use cases envisioned for 5G.
Why non-standalone 5GNR is important
5G Insights October 2017
5G: essential for the Fourth Industrial Revolution
Standards body 3GPP agreed in March this year to accelerate its work on a non-standalone mode for 5GNR as applied to enhanced mobile broadband use cases. Industry pressure was already building to set an early date for the standardization of NSA following an earlier decision by 3GPP to prioritize this area of its work to avoid the risk of fragmentation around 5G. With operators in North America and Asia forging ahead with early deployment of pre-standard 5G networks, urgency was building around the need for a single, global 5G standard.
The decision to accelerate NSA 5GNR was supported by a large group of operators and vendors including AT&T, Ericsson, NTT DoCoMo, Qualcomm, SK Telecom, and Vodafone, on the basis that it would facilitate large-scale trials and early deployments of standards-based 5G technology sooner than might otherwise have been the case.
NSA 5GNR is an intermediate step in 5G standardization that allows for the introduction of a new 5G radio interface, with its associated benefits in terms of enhanced data rates, but using an existing LTE evolved packet core network as an anchor. Under the configuration adopted for accelerated NSA 5GNR, control plane functionality continues to be routed through the LTE network, while the data plane either runs on the LTE network or connects through a separate interface directly from the EPC to the 5GNR.
The decision to accelerate work on the non-standalone 5GNR standard means it will be completed by the end of 2017, and the standard finalized by March 2018, with commercial equipment expected to be available by late 2018 or early 2019. This is six months ahead of standalone 5GNR, work on which will be finalized by end-2018, at which point both non-standalone and standalone 5GNR will be incorporated into 3GPP Release 15. Standalone 5GNR will use the new 5G core network architecture as part of a fully autonomous 5G radio and core network.
The accelerated timeline for NSA 5GNR will serve to increase the certainty around plans that some operators have to prepare the 5G technology for deployment in time for specific large-scale events, such as the Tokyo Summer Olympics in 2020.
Initial 5G deployments will support enhanced MBB
Because it reuses elements of the LTE radio and core network, the benefits of NSA 5GNR will be limited to eMBB and fixed wireless broadband services. Only with the introduction of a 5G core network will support for network slicing and new use cases such as critical communications and IoT be possible. This will not be addressed until at least Phase 2 of 5G standardization.
By being an extension of the existing mobile data model, eMBB does not represent such a major step for operators when compared with some of the more complex architectures envisioned for 5G and needed to support additional use cases. It therefore represents a relatively straightforward migration path from LTE, while also helping to meet the major and most immediate challenges facing operators, such as the explosion in data traffic driven by the growing use of video.
Nokia believes that the early availability of 5G specifications will give greater certainty to operators. Coupled with the early release and global momentum behind new 5G spectrum, such as the 3.5GHz band, larger trials are likely to take place earlier than anticipated a year ago, the vendor says.
The consensus at the 5G World event in London during June was that the industry is broadly aligned behind the new 3GPP standards timelines for 3GPP Release 15. The higher speeds and greater capacity offered by 5G will go a long way to help justify the launch business case as they will allow operators to add capacity for mobile broadband services at a time when new spectrum will be needed to meet rapidly growing mobile broadband usage.
Even so, in the medium term, industry opinion sees support for use cases other than eMBB as fundamental to 5G success. Nokia regards critical communications, massive IoT, and the capability to address vertical markets as among the most transformative aspects of 5G, along with enabling cloud-optimized networks and a data center-type model along the lines of that developed by web-scale players. For this reason, the vendor believes the market will move to a standalone model with a 5G core after an initial phase.
New use cases such as critical communications and IoT will become available sometime after the completion of Phase 2 of 5G standardization (3GPP Release 16) in 2020, and will bring a number of significant new capabilities to the network, such as extremely low latency and error-free transmission. These use cases will require radical changes to the network through the introduction of new architectures such as a common core, network virtualization and cloud, redistribution of resources through the introduction of small cells and edge computing, the introduction of techniques such as network slicing, and major investment in network coverage and in areas such as transport and backhaul. Many of these technologies are as yet largely unproven and will take time to implement.
Most operators are not changing their plans
Ovum has found little evidence so far to suggest that operators are changing their 5G launch plans following the NSA 5GNR acceleration agreement. In a survey carried out among operators following 3GPP’s March announcement, it was apparent that the majority of respondents who were aware of the change (43%) have not altered their planned 5G launch dates as a result. A further 35% had not yet fully examined the non-standalone proposal, or were unaware of it.
However, by virtue of the impetus it will provide to the overall 5G commercial market, Ovum believes that NSA 5GNR could still have an effect in the medium term, and although most operators will wait until after Phase 2 in 2020 to go commercial, they might do so faster post-2020 due to NSA 5GNR.
Julian Bright is senior analyst at Ovum
This article first appeared in Telecom Asia 5G Insights October 2017 Edition