Content for  TS 22.261  Word version:  19.4.0

Steering of roaming allows the HPLMN (or subscribed NPN) to steer a UE to a VPLMN or NPN on which the HPLMN (or subscribed NPN) wants the UE to register, when the UE registers on another VPLMN or NPN. This capability can be needed for reasons e.g. reselection to a higher priority PLMN, or NPNs, based on business arrangements.

The following set of requirements complement the requirements listed in clause 3.2.2.8 of TS 22.011. The 5G system shall support a mechanism for the HPLMN to control the timing when a UE registered on a VPLMN, in automatic mode (see clause 3.1 of TS 23.122) and currently in CONNECTED mode, enters IDLE mode and initiates higher priority PLMN selection based on the type of ongoing communication. The UE shall be able to delay conforming to steering of roaming control information from the HPLMN while it is engaged in priority service (e.g. emergency call, MPS session), or a service defined by HPLMN policy not to be interrupted (e.g. MMTEL voice/video call). The mechanism mentioned above in this clause shall be available to the HPLMN even if the VPLMN the UE is registered on is compliant to an earlier release of the 5G system. The 5G system shall support mechanisms to enable a credentials holder (e.g. HPLMN or subscribed standalone NPN) to send steering of roaming information to a UE for selecting standalone NPNs (e.g prioritized list of preferred NPNs).

A mobile network can fail to provide service in the event of a disaster (for example a fire.) The requirements listed in this clause provide the 5GS with the capability to mitigate interruption of service. UEs can obtain service in the event of a disaster, if there are PLMN operators prepared to offer service. The minimization of service interruption is constrained to a particular time and place. To reduce the impact to the 5G System and EPS of supporting Disaster Roaming, the potential congestion resulting from an influx or outflux of Disaster Inbound Roamers is taken into account. Scenarios where network failures render the network subject to a disaster unable to authenticate its subscribers are excluded.

The 3GPP system is expected to support various enhanced UAV scenarios, especially for a wide range of applications and scenarios by using low altitude UAVs in various commercial and government sectors.

The 3GPP system supports service requirements and KPIs related to command and control (C2), payload (e.g. camera) and the operation of radio access nodes on-board of UAVs. The associated requirements are described in TS 22.125.

Audio-Visual (AV) production includes television and radio studios, live news-gathering, sports events, music festivals, among others. Typically, numerous wireless devices such as microphones, in-ear monitoring systems or cameras are used in these scenarios. In the future, the wireless communication service for such devices are expected to be provided by a 5G system. AV production applications require a high degree of confidence, since they are related to the capturing and transmission of data at the beginning of a production chain. This differs drastically when compared to other multimedia services because the communication errors will be propagated to the entire audience that is consuming that content both live and on recorded media. Furthermore, the transmitted data is often post-processed with filters which could actually amplify defects that would be otherwise not noticed by humans. Therefore, these applications call for uncompressed or slightly compressed data, and very low probability of errors. These devices will also be used alongside existing technologies which have a high level of performance and so any new technologies will need to match or improve upon the existing workflows to drive adoption of the technology. The 3GPP system already plays an important role in the distribution of AV media content and services. Release 14 contains substantial enhancements to deliver TV services of various kinds, from linear TV programmes for mass audiences to custom-tailored on-demand services for mobile consumption. However, it is expected that also in the domain of AV content and service production, 3GPP systems will become an important tool for a market sector with steadily growing global revenues. There are several areas in which 3GPP networks can help to produce AV content and services in an efficient and flexible manner.

The 5G system supports the communication services for video, imaging and audio for professional applications. The associated requirements are described in TS 22.263.

The 5G system is expected to meet the service requirements for critical medical applications where critical medical applications denote medical devices and applications involved in the delivery of care for patient's survival. Additionally, as the medical industry undergoes a shift to value-based healthcare, where companies and healthcare providers have to move to business models based on providing clinical value with cost efficiency, the 5G system can help to adopt new and more efficient care delivery models in order to reduce administrative and supply costs. On this matter, 5G technology can especially have an important impact by:

• enabling superior monitoring capability means thus improving the effectiveness of preventive care,
• enabling shifting care location from hospitals to homes and other lower cost facilities,
• improving operating room planning, enabling streamlining equipment usage and simplifying operating theater implementation,
• Enhancing cooperation in critical situations between ambulance and hospital staff.

The 5G system shall support the communication services for critical medical applications. The associated requirements are described:

• in TS 22.104 for the requirements related to controlling both local or remote robotic diagnosis or surgery systems,
• In TS 22.263 for the requirements related to high quality medical imaging and augmented reality systems located in hybrid operating rooms, in remote healthcare facilities or ambulances,
• In clause 7.5 of TS 22.261 for the requirements on the support of tele-diagnosis or tele-monitoring systems,
• In clauses 6.10, 8.2 and 8.9 of TS 22.261 for the requirements on the security of medical data that fulfil regulatory requirements.

In order to support enhancement of service function chaining for 5G networks beyond the requirements for FMSS in TS 22.101, the network operator defines service function chaining policies for service function chaining to steer the traffic associated to the application and its users on per UE basis to appropriate ordered service functions. A service function chain for 5G networks contains service functions such as firewall functions, NAT, antimalware, parental control, DDoS protection, TCP proxies, load balancers, KPI monitoring, and video optimization, etc.

The following requirements apply for supporting enhancement of service function chaining for 5G networks:

• The network operator shall be able to define and modify service function chaining policies for steering traffic on per application per UE basis through required service function chaining with ordered service functions to improve the user's QoE.
• Service functions chaining policies shall be able to distinguish between upstream and downstream traffic.
• The coexistence of traffic with and without service function chaining shall be supported.
• Service function chaining shall provide suitable means for authorized third parties to request a chain of service functions provided by the network operator based on operator's service function chaining policies.
• In case of roaming, the HPLMN shall be able to apply traffic steering policies and service function chaining polices for home routed traffic.
• In case of roaming with local breakout, the HPLMN shall be able to provide the traffic steering policies and service function chaining policies to the VPLMN providing local breakout with support of service function chaining.
• Service function chaining shall support deployments where the Hosted Services are provided by the operator and deployments where the Hosted Services are provided by a third party.

 

• The service function management shall allow the operator to create, modify, and delete a service function based on operator's service function chaining policies.
• The service function management shall allow the operator to create, configure, and control a chain of service functions per application and its users on per UE basis based on operator's policy or request from third parties.
• The service function management shall be able to manage service function chaining for deployments where the Hosted Services are provided by the operator and for deployments where the Hosted Services are provided by a third party.

5G systems rely on reference precision timing signals for network synchronization in order to operate. These synchronization references are generated by Primary reference Time Clocks that typically get the timing reference from GNSS receivers and in order to meet the relevant synchronization requirements also during failure conditions, the synchronization network designs typically include means to address potential degradation of the GNSS signal performance. Some deployment of 5G involve applications that themselves can be sensitive to any degradation of the timing signal. In such cases it is beneficial for the 5G system to be enhanced to act as a backup for loss of their GNSS references. In some implementations, timing resiliency enhancements to the 5G system can work in collaboration with different types of time sources (e.g., atomic clock, time service delivered over the fibre) to provide a robust time synchronization. 5G as a consumer of time synchronization benefits from timing resiliency which enables the support of many critical services within the 5G network even during the event of a loss or degradation of the primary GNSS reference timing. Additionally, for time critical services (e.g. financial sector or smart grid), the 5G system can operate in collaboration with or as backup to other timing solutions. A base of clock synchronization requirements when 5G is providing a time signal, if it is deployed in conjunction with an IEEE TSN network or if it is providing support for IEEE 1588 related protocols, is included in clause 5.6 of TS 22.104. The enhancements in this clause build on this to add timing resiliency to the 5G system enabling its use as a replacement or backup for other timing sources.

The 5G system shall support enhanced timing resiliency in collaboration with different types of time sources (e.g., GNSS, TBS/MBS [33] [34], Sync over Fiber [34]) to provide a robust time synchronization. The 5G system shall be able to maintain accurate time synchronization as appropriate for the supported applications in the event of degradation or loss of the primary timing reference (e.g., GNSS).

The 5G system shall be able to support mechanisms to monitor for timing source failure (e.g., GNSS). The 5G system shall be able to detect when reference timing signals (e.g., from GNSS or other timing source) are no longer viable for network time synchronization. The 5G system shall support a mechanism to determine if there is degradation of the 5G time synchronization. The 5G system shall be able to support mechanisms to indicate to devices (e.g., UEs, applications) that there is an alternate time source available for use (e.g., 5G system internal holdover capability, atomic clock, Sync over Fiber, TBS, GNSS), taking into account the holdover capability of the devices. The 5G system shall be able to detect when a timing source fails or is restored for network time synchronization. The 5G system shall support mechanisms to monitor different time sources and adopt the most appropriate. The 5G system shall support a mechanism to report timing errors such as divergence from UTC and time sync degradation to UEs and 3rd party applications.

The 5G system shall support a mechanism for a 3rd party application to request resilient timing with specific KPIs (e.g., accuracy, interval, coverage area).