Tech-invite3GPPspecsSIPRFCs
Overview21222324252627282931323334353637384‑5x

Content for  TR 22.835  Word version:  18.0.0

Top   Top   Up   Prev   Next
1…   5…   5.4…   5.8…   5.11…

 

5.8  Use case for application-based preference

5.8.1  Description

Applications using Network Slice(s) offered on different radio resources may be used differently in location and time. This brings motivation for the 5G System to support a mechanism to establish and manage a preference ordering among subscribed applications/services for use in cell (re)selection.
Application preference could be set by the user or derived based on the user's application usage pattern. Application preference information in the network can be overridden by application activation, such that activating an application with a lower preference order may trigger a change in serving network slice (assuming no other application is also active on that slice) and cell (re)selection if the newly activated application requires a different radio resource.
Up

5.8.2  Pre-conditions

Slice M & Slice N are two slices provided by the same Operator. Services from Slice M are provided over frequency band FR1 and services from slice N are provided over frequency band FR2.
Slice M provides VPN and streaming services while slice N provides VPN and AR/VR-Gaming services. The UE's shown in the illustration have subscriptions to applications provided by both the slices M and N. The key difference in network slice selection lies in the application preference order used by each UE.
Rama and Krishna work in different companies at the same location (e.g., an office building). Rama has a WFH (Work from Home) option which he can use frequently while Krishna does not have a WFH option from his company but may be allowed WFH in rare situations. Both their homes are located in the same service area. Rama likes to use his AR/VR-Game application during office-breaks while at the office. Krishna mostly uses his streaming service during office-breaks while at the office. Both use their streaming service application most after office hours when at home.
  • Rama (UE1) and Krishna (UE2) have subscriptions to applications VPN, AR/VR-Game and a streaming service.
  • Rama has his preference profiles set in the following order:
Rama's UE Application Preference Profile Setting
Profile Time of Day, Day Location Preference-1 Preference-2 Preference-3
Work Profile9-5 Work Day SettingOfficeVPNAR/VR-GameStreaming service
Rest of the Time/DaysAnyStreaming ServiceAR/VR-GameVPN
WFH Profile9-5 WFH Day SettingHomeVPNStreaming ServiceAR/VR-Game
Rest of the Time/DaysAnyStreaming ServiceAR/VR-GameVPN
Default ProfileAnyAnyStreaming ServiceAR/VR-GameVPN
 
  • Krishna does not have his preference pre-set, however it is established by the 5G System based on his usage pattern in below order:
Krishna's Application Preference Setting derived by 5G System
Time of Day Location Preference-1 Preference-2 Preference-3
9-5 Work DaysOfficeVPNStreaming ServiceAR/VR-Game
Rest of the Time/DaysAnyStreaming ServiceVPNAR/VR-Game
Up

5.8.3  Service FlowsWord‑p. 23
For a normal working day at the office, Rama's UE selects slice M and Krishna's UE selects slice N based on their preferences.
(not reproduced yet)
Figure 5.8.3-1: Applications preferred network slices for Rama and Krishna during Workdays (Working Hours)
Up
Both return to their homes after office hours. Both Rama's UE and Krishna's UE select slice M based on their preferences.
(not reproduced yet)
Figure 5.8.3-2: Applications preferred network slices for Rama and Krishna during Evenings (off-Working Hours)
Up
During a WFH Day for Rama, he changes his profile setting to use 'WFH Profile'. While Krishna goes to office as usual. Rama's UE stays on slice M instead of switching to Slice N while Krishna's UE selects slice M as usual at the office.
(not reproduced yet)
Figure 5.8.3-3: WFH Scenario for Rama and normal work day for Krishna.
Up
Once, both Rama and Krishna meet at a conference and become friends. Rama invites Krishna to join him to play an AR/VR game during office-breaks. Krishna accepts the invitation and subsequently starts playing the AR/VR game during office-breaks instead of watching his streaming service. Initiating the AR/VR-Gaming application triggers Krishna's UE to use the least preferred application during his office breaks and causes it to (re)select a cell offering Slice N
(not reproduced yet)
Figure 5.8.3-4: Slice Switch Triggered for Krishna due to AR/VR-Game usage
Up
The 5G System now derives/updates the new preference for Krishna based on AR/VR-Game Usage during office breaks.
Krishna's Preference Setting derived by 5G System
Time of Day Location Preference-1 Preference-2 Preference-3
9-5 Work DaysOfficeVPNAR/VR-GameStreaming Service
Rest of the Time/DaysAnyStreaming ServiceVPNAR/VR-Game
Up

5.8.4  Post-conditionsWord‑p. 26
Both Rama and Krishna are able to access their preferred application(s) in a timely and efficient manner.

5.8.5  Existing features partly or fully covering the use case functionality

The 5G system shall allow the operator to assign a UE to a network slice, to move a UE from one network slice to another, and to remove a UE from a network slice based on subscription, UE capabilities, the access technology being used by the UE, operator's policies and services provided by the network slice.
Establishing UE usage patterns based on time/date/location is supported by TS 23.503.

5.8.6  Potential New Requirements needed to support the use case

[PR.5.8.6-1]
The 5G system shall support a mechanism for a UE to select and access network slice(s) based on UE capability, ongoing application, and policy (e.g., application preference).
[PR.5.8.6-2]
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.

5.9  Regionally different resources for network slices

5.9.1  Description

Installation of radio equipment needs a lot of work to be done. Thus, typically, even if an operator owns a certain radio frequency nationally, the operator may gradually deploy radio equipment one region by one region, expanding coverage gradually. As a result, even if some network slice, for example, such as a slice for IMS service is provided nationally, the used frequency band for that network slice may be different per different areas.

5.9.2  Pre-conditions

Figure 5.9.2-1 shows the use case scenario where network slices use different radio resources for different areas.
(not reproduced yet)
Figure 5.9.2-1: Initial condition
Up
In this figure, it is assumed that
  • Subscription and configuration:
    • UE A1 has a subscription to slice M.
    • UE A2, A3 and A4 have subscription to slice N.
  • Deployment:
    • F1 is used at all areas. F2 is available only at area around GB, e.g. in a highly populated area.
    • Due to high demand of applications related to Slice N, at area around GB, frequency F2 is dedicated to serve the network slice N, and F1 is dedicated to serve other network slices such as network slice M.

5.9.3  Service FlowsWord‑p. 27
Following is service flow for UE A1 and A2 which move from area GA to area GC:
  • UE A1 and A2 are serviced with network slices over F1 at area GA.
  • UE A1 continues to be serviced with network slice M over F1 toward area GB. Because F1 at area GB does not support slice N, the network moves the UE A2 to F2 to provide service continuity for network slice N from area near GD. While the frequency used for Slice N changes, the service interruption to applications over Slice N is minimized.
  • UE A1 continues to be serviced with network slice M over F1 toward area GC. UE A2 moves back to F1 to get network slice N from as the UE moves along from GB to GC. While the frequency used for Slice N changes, the interruption to application over Slice N is minimized.
Following is service flow for UE A3 which is stationary at area GD:
  • UE A3 is located at the boundary area where the used frequencies for a network slice N differ. To prevent unnecessary power consumption, service interruption and increased signaling, frequency change between F1 and F2 needs to be minimized, when the UE A3 is serviced with network slice N.
Following is a service flow for UE A4 which moves from area GA to area GB:
  • UE A4 is serviced with network slice N over F1 at area GA. When application ends, the user of UE A4 switches off the UE A4.
  • While the UE A4 is switched off, the user moves from the area GA to the area GB.
  • When the user arrives at the area GB, the user turns on the UE A4 and starts finds cells, beginning with F1 which is the last used frequency.
  • The UE A4 finds out that F1 does not support Slice N. In the end, the UE access cells on F2 and gets service for network slice N over F2 at area GB.
Up

5.9.4  Post-conditions

Following Figure 5.9.4-1 shows the status at the end of service flow.
(not reproduced yet)
Figure 5.9.4-1: End result
Up

5.9.5  Existing features partly or fully covering the use case functionality

Following are service requirements that can be drawn out of service description in previous sections and that can be supported with existing specifications:
  • 3GPP shall support the same network slice to be configured over different frequencies at different areas.
  • 3GPP shall support service continuity for a network slice at the boundary where radio resources configured for the network slice change, for a UE in Connected mode.
However, the existing specification does not yet provide specific means when the UE moves between different regions in Idle mode.
  • 3GPP shall support to minimize the time that takes for a UE to be able to access radio resource configured for a network slice when the used radio resources for the network slice change e.g. during mobility, power cycle.
Up

5.9.6  Potential New Requirements needed to support the use caseWord‑p. 28
Following new requirements can be derived from this use case:
[PR.5.9.6-1]
5G system shall support a mechanism to minimize service interruption for a UE when different radio resources are configured for a network slice in different geographical areas and when the UE crosses the geographic area boundaries.

5.10  Isolation of resource for network slice

5.10.1  Description

Due to various sources and ways to gain right to use specific frequency resources, even within a continuous frequency range, different blocks of frequency within the range can be restricted to different purposes.
Also, based on the requirements on the levels of isolation and security, access by a network slice beyond the authorized blocks should not occur, even if the frequency blocks are adjacent.

5.10.2  Pre-conditions

Figure 5.10.2-1 shows the use case scenario where frequency band are partitioned into multiple subbands.
(not reproduced yet)
Figure 5.10.2-1: Initial condition
Up
In this figure, it is assumed that
  • Subscription:
    • UE A1 and A4 have subscription to slice M, and this slice M is optimized e.g. for IoT type of application.
    • UE A2 and A4 have subscription to slice N, and this slice N is optimized e.g. for eMBB type of application.
    • UE A3 has subscription to slice O, and this slice O is optimized e.g. for URLLC. The users or application providers request isolation of radio resources used for this network slice.
  • Deployment:
    • The cell is configured to use frequency band which is from F1 to F2.
    • The frequency band is sub-divided into three subbands. The allocated frequency for the first subband spans from F1 to Fa. The allocated frequency for the second subband spans from Fa to Fb. The allocated frequency for the third subband spans from Fb to F2.
    • The first subband is used for slice O. The second subband is used for slice N. The third subband is used for slice M. in addition, third subband can be used for common procedure, e.g. SIB.
Up

5.10.3  Service FlowsWord‑p. 29
Following is service flow for UE A1, A2, A3 and A4:
  • After power-on, UE A1, A2, A3 and A4 camp on a cell, where the subscribed slices can be provided. Because the UEs are accessing the same cell supporting at least one of the subscribed network slices, there is no need for the UEs to move to other cells.
  • When applications start, UE A1 transmits and receives data over Slice M, which is restricted to subband 3.
  • When applications start, UE A2 transmits and receives data over Slice N, which is restricted to subband 2.
  • When applications start, UE A3 transmits and receives data over Slice O, which is restricted to subband 1.
  • When applications start, UE A4 transmits and receives data. For traffic configured to use Slice M, the transmission and reception is performed using radio resources within subband 3. For traffic configured to use Slice N, the transmission and reception is performed within radio resources within subband 2. Due to isolation requirement or service agreement for the network slice, traffic for Slice M is not transported over subband 2. Similarly, traffic for Slice N is not transported over subband 3.
  • As demands for the network slice changes according to the number of UEs for the network slice or time of the day, the network adjusts the allowed frequency range of each network slice. There is no recognized impact to the user experience.
Up

5.10.4  Post-conditions

Following Figure 5.10.4-1 shows the status at the end of service flow.
For the transport of user traffic, each UE may use different part of frequencies of the cells, which corresponds to the configured frequency range for each network slice.
(not reproduced yet)
Figure 5.10.4-1: End result
Up

5.10.5  Existing features partly or fully covering the use case functionality

Following service requirements are already supported by current specifications:
  • 3GPP system shall provide means to support flexibility in configuring the allowed or restricted radio resources for a network slice.
  • 3GPP system shall support for a network slice to use specific portion of the radio resources (e.g. frequency range) within a cell.
  • 3GPP system shall be able to allow or disallow user traffic for a network slice to be multiplex with the user traffic for other network slice, based on the security and isolation requirement of the network slice.
BWP (Bandwidth Part) operation defined in TS38.300 [4] does not provide a UE with the support for providing different network slices on different frequency bands, when the UE is authorized to use multiple network slices.
Up

5.10.6  Potential New Requirements needed to support the use caseWord‑p. 30
Following new requirements can be derived from this use case:
[PR.5.10.6-1]
5G system shall be able to minimize service interruption when configured radio resource (e.g. frequency range) for a network slice changes.


Up   Top   ToC