Content for TR 22.835 Word version: 18.2.0

1… 5… 5.3… 5.4… 5.7… 5.8… 5.9… 5.10… 5.12… 6…

6 Consolidated Potential Requirements p. 35

Following are consolidated potential requirements.

n of the VPLMNs the UE is authorised to register to in order to use specific network slices.

Table 6-1: Consolidated Potential Requirements

CPR #	Consolidated Potential Requirement	Original PR #
CPR-001	For a UE authorized to access multiple network slices of one operator which cannot be simultaneously used by the UE (e.g. due to radio frequency restrictions), the 5G system shall be able to support the UE to access the most suitable network slice in minimum time (e.g. based on the location of the UE, ongoing applications, UE capability, frequency configured for the network slice).	[PR.5.3.6-1]
CPR-002	For a UE authorized to access to multiple network slices of one operator which cannot be simultaneously used by the UE (e.g. due to radio frequency restrictions), the 5G system shall minimize service interruption time when the UE changes the access from one network slice to another network slice. (e.g. based on changes of active applications).	[PR.5.3.6-2]
CPR-003	5G system shall minimize signaling exchange and service interruption time for a network slice, e.g. when restrictions related to radio resources change (e.g., frequencies, RATs).	[PR.5.4.6-1]
CPR-004	For a roaming UE activating a service/application requiring a network slice not offered by the serving network but available in the area from other network(s), the HPLMN shall be able to provide the UE with prioritization information of the VPLMNs with which the UE may register for the network slice.	[PR.5.5.6-1]
CPR-005	The 5G system shall be able to generate charging information regarding the used radio resources e.g. used frequency bands.	[PR.5.11.6-1]
CPR-006	The 5G system shall be able to minimize power consumption of a UE (e.g. reduce unnecessary cell measurements), in an area where no authorized network slice is available.	[PR.5.1.6-1]
CPR-007	When a UE moves out of the service area of a network slice for an active application, the 5G system shall be able to minimize impact on the active applications (e.g., providing early notification). NOTE 1: Various methods can be used to detect whether the UE moves toward the border area and to notify the UE.	[PR.5.2.6-1]
CPR-008	The 5G system shall support a mechanism for a UE to select and access network slice(s) based on UE capability, ongoing application, radio resources assigned to the slice, and policy (e.g., application preference).	[PR.5.8.6-1]
CPR-009	The 5G system shall support a mechanism to optimize resources of network slices (e.g., due to operator deploying different frequency to offer different network slices) based on network slice usage patterns and policy (e.g., application preference) of a UE or group of UEs.	[PR.5.8.6-2]
CPR-010	For traffic pertaining to a network slice offered via a relay node, 5G system shall use only radio resources (e.g. frequency band) allowed for the network slice. NOTE 2: Allowed radio resources (e.g., frequency band) may be different for direct network connections (between UE and NG-RAN) than for backhaul connections (between the relay node and the NG-RAN).	[PR.5.13.6-1]
CPR-011	For UEs that have the ability to obtain service from more than one VPLMN simultaneously, the following requirements apply: When a roaming UE with a single PLMN subscription requires simultaneous access to multiple network slices and the network slices are not available in a single VPLMN, the 5G system shall enable the UE to: be registered to more than one VPLMN simultaneously; and use network slices from more than one VPLMN simultaneously The HPLMN shall be able to authorise a roaming UE with a single PLMN subscription to be registered to more than one VPLMN simultaneously in order to access network slices of those VPLMNs. The HPLMN shall be able to provide a UE with permission and prioritisation information of the VPLMNs the UE is authorised to register to in order to use specific network slices. NOTE 3: The above requirements assume certain UE capabilities, e.g. the ability to be connected to more than one PLMN simultaneously.	[PR.5.6.6-1]

7 Conclusions and Recommendations p. 37

This document analyses a number of use cases to enhance the support of network slice. The resulting potential requirements have been consolidated in clause 6.

It is recommended that the consolidated potential requirements identified in this TR are considered as the basis of normative requirements in order to better serve the communication services.

A Consideration for different type of frequency p. 38

Frequency band defined in 3GPP can be classified into FDD frequency and TDD frequency as shown in Table 5.2-1 of TS 38.101-1 and TS 38.101-2. In case of TDD system, the same frequency is used for both UL and DL. However, in case of FDD system, UL frequency is different from DL frequency. Thus, when radio resource restriction scenario is discussed, care should be taken by considering these variations e.g. frequency used for both DL/ UL, UL only or DL only.

In addition, 5G system introduces further flexibility in using frequency band. For example, SUL (Supplementary UL) and SDL (Supplementary DL) are frequency band either defined only in DL or only in UL, as described in annex B of TS 38.300. This spectrum is used to assist other frequency band, e.g. when base frequency band lacks coverage in either DL or UL, then SUL or SDL can be used to replace the base frequency band. If the SUL and/or SDL band is restricted for a certain network slice, some UEs may experience reduced coverage for the network slice.

Aspects related to carrier aggregation also needs to be considered similarly, because it is used to support QoS requirement by using different combination of DL bands and UL bands, e.g. using three DL bands together with one UL bands to boost downlink data rate. If allowed network slices differs for different frequency bands, then operation of CA also needs to take this into account for a network slice.