The first formal specifications for 5G technology from 3GPP will define New Radio technology, and will be ready in June 2018, despite a request from an influential group of operators for a slightly different timeline.
3GPP, the body that consolidates and defines specifications for mobile technology into standards authorities, has released its workplan for Release-15 (R15) – showing how specifications for a New Radio interface, in frequencies both below and above 6GHz, will be taken forward.The body said that it hopes to start defining the next generation architecture in December 2016, and then the 5G New Radio in March 2017. Standards will be frozen in June 2018.
The announcement followed a meeting held in Busan from 13-16 June, 2016. At that meeting there was pressure from a significant group of operators and vendors to reschedule the working progress of the Release, to make sure that those that rush to release 5G early do not jeopardise forwards-compatibility in the standards. The group wanted to make sure that 3GPP could move to avoid technology fragmentation as operators move to rollout technology before specifications have been finalised and standardised.
A submission from this group noted that there is a “Large risk that competitive pressures will lead to others adopting “non-standard” 5G deployments” by 2018. However, the group said it was vital that the 3GPP “stays focussed” on meeting the original goals of 5G New Radio. To do this it said that 3GPP must evaluate and document how forwards compatibility can be achieved before it starts working on detailed specifications.
This group’s proposal was that specification work on the New Radio specification be phased, with nonstandalone operation – 5G with LTE as the control plane anchor to the core network – completed by December 2017. Standalone operation could then be completed by September 2018.
However, 3GPP said that specifications for standalone and non-standalone options would instead be frozen by June 2018.
As its working groups do that, they will define two options for New Radio architecture – one that keeps the control plane anchored in the current LTE network, and another that includes control and user plane solely in 5G, thereby enabling 5G radio to be deployed as a standalone.
At the June meeting in Busan, Deutsche Telekom summarised the possible architecture options that take into account LTE Radio in its Release 15 version (ie a very advanced LTE) and also Next Generation Radio (5G). Plus any architecture would have to provide aggregation of both technologies in two variants. Any architecture must also incorporate the existing LTE core network (EPC) and a next generation core (NGCN).
This combination results in 12 options. These are:
1. Standalone LTE, connected to the EPC. Simply the current situation.
2. Standalone New Radio connected to the NGCN
3. Non-standalone v1A New Radio connected to the LTE network, and then onwards to the EPC.
3a Nonstandalone v2: A new radio with a direct interface (1A) to the EPC, alongside an “LTE assisted” link.
4. A version that connects the LTE network to the Next Gen core network, via the New Radio network.
4a A version that connects the LTE network directly to the Next Gen Core and also via the NR.
5. A version that connects the LTE network directly and only to the NGCN.
6. A standalone NR version that provides a sole and direct link between the NR and the EPC
7 A version that connects the New Radio to the NGCN via the LTE network
7a A version that is like 7 but includes a simultaneous direct NR-to-NGCN link.
8. An architecture that connects LTE to EPC via the New Radio
8a An architecture that combines a direct LTE-EPC interface with version 8.
In other words there are 11 new options for designing the architecture for a new radio and new core network.The 3GPP has said that its SA2 (System Architecture) group should look to deliver options 2,4,5 and 7, and it should be clear by March 2017 if it will be able to do that.
– R15 will be the first 3GPP release to include specifications for 5G technology, and is set to be “frozen” (ie. completed) in June 2018.
– The specs will formalise “anchored” (control plane remains in LTE) and “standalone” (the new radio contains its own control plane) operation.
– 3GPP has laid out the steps it will take to get to that point over the next two years.
– R13, which was frozen in March 2016, and R14, add only technology to the LTE-A progression path, now known as LTE-A PRO.
– A group of vendors and operators submitted a proposal for a rescheduling
* (Vodafone, AT&T, China Mobile, China Unicom, KDDI, NTT DOCOMO, SouthernLINC, Sprint, Telus, Acer, Ericsson, Hitachi, HTC, Huawei, Intel, ITRI, Mediatek, Mitsubishi Electric, Nokia, Qualcomm, Sony)