Content for  TS 22.261  Word version:  20.0.0

5G introduces the opportunity to design a system to be optimized for supporting diverse UEs and services. While support for IoT is provided by EPS, there is room for improvement in efficient resource utilization that can be designed into a 5G system whereas they are not easily retrofitted into an existing system. Some of the underlying principles of the potential service and network operation requirements associated with efficient configuration, deployment, and use of UEs in the 5G network include bulk provisioning, resource efficient access, optimization for UE originated data transfer, and efficiencies based on the reduced needs related to mobility management for stationary UEs and UEs with restricted range of movement. As sensors and monitoring UEs are deployed more extensively, the need to support UEs that send data packages ranging in size from a small status update in a few bits to streaming video increases. A similar need exists for smart phones with widely varying amounts of data. Specifically, to support short data bursts, the network should be able to operate in a mode where there is no need for a lengthy and high overhead signalling procedure before and after small amounts of data are sent. The system will, as a result, avoid both a negative impact to battery life for the UE and wasting signalling resources. For small form factor UEs it will be challenging to have more than 1 antenna due to the inability to get good isolation between multiple antennas. Thus, these UEs need to meet the expected performance in a 5G network with only one antenna. Cloud applications like cloud robotics perform computation in the network rather than in a UE, which requires the system to have high data rate in the uplink and very low round trip latency. Supposed that high density cloud robotics will be deployed in the future, the 5G system need to optimize the resource efficiency for such scenario. Additional resource efficiencies will contribute to meeting the various KPIs defined for 5G. Control plane resource efficiencies can be achieved by optimizing and minimizing signalling overhead, particularly for small data transmissions. Mechanisms for minimizing user plane resources utilization include in-network caching and application in a Service Hosting Environment closer to the end user. These optimization efforts contribute to achieving lower latency and higher reliability. Diverse mobility management related resource efficiencies are covered in clause 6.2. Security related resource efficiencies are covered in clause 8.8.

5G is designed to meet diverse services with different and enhanced performances (e.g. high throughput, low latency and massive connections) and data traffic model (e.g. IP data traffic, non-IP data traffic, short data bursts and high throughput data transmissions). User plane should be more efficient for 5G to support differentiated requirements. On one hand, a Service Hosting Environment located inside of operator's network can offer Hosted Services closer to the end user to meet localization requirement like low latency, low bandwidth pressure. These Hosted Services contain applications provided by operators and/or trusted 3rd parties. On the other hand, user plane paths can be selected or changed to improve the user experience or reduce the bandwidth pressure, when a UE or application changes location during an active communication, or due to operational needs in the service hosting environment (e.g. based on usage information). The 5G network can also support multiple wireless backhaul connections (e.g. satellites and/or terrestrial), and efficiently route and/or bundle traffic among them.

Based on operator policy, application needs, or both, the 5G system shall support an efficient user plane path between UEs attached to the same network, modifying the path as needed when the UE moves during an active communication. The 5G network shall enable a Service Hosting Environment provided by operator. Based on operator policy, the 5G network shall be able to support routing of data traffic between a UE attached to the network and an application in a Service Hosting Environment for specific services, modifying the path as needed when the UE moves during an active communication. Based on operator policy, application needs, or both, the 5G system shall support an efficient user plane path, modifying the path as needed when the UE moves or application changes location, between a UE in an active communication and:

• an application in a Service Hosting Environment; or
• an application server located outside the operator's network; or
• an application server located in a customer premises network or personal IoT network.

The 5G network shall maintain user experience (e.g. QoS, QoE) when a UE in an active communication moves from a location served by a Service Hosting Environment to:

• another location served by a different Service Hosting Environment; or
• another location served by an application server located outside the operator's network; or
• another location served by an application server located in a customer premises network or personal IoT network, and vice versa.

The 5G network shall maintain user experience (e.g. QoS, QoE) when an application for a UE moves as follows:

• within a Service Hosting Environment; or
• from a Service Hosting Environment to another Service Hosting Environment; or
• from a Service Hosting Environment to an application server located place outside the operator's network; or
• from a Service Hosting Environment to an application server located in a customer premises network or personal IoT network, and vice versa.

The 5G network shall be able to interact with applications in a Service Hosting Environment for efficient network resource utilization and offloading data traffic to the most suitable Service Hosting Environment, e.g. close to the UE's point of attachment to the access network or based on usage information. The 5G network shall support configurations of the Service Hosting Environment in the network (e.g. access network, core network), that provide application access close to the UE's point of attachment to the access network. The 5G system shall support mechanisms to enable a UE to access the closest Service Hosting Environment for a specific hosted application or service. The 5G network shall enable instantiation of applications for a UE in a Service Hosting Environment close to the UE's point of attachment to the access network. The 5G system shall be able to suspend or stop application instances in a Service Hosting Environment. Based on operator policy, the 5G system shall provide a mechanism such that one type of traffic (from a specific application or service) to/from a UE can be offloaded close to the UE's point of attachment to the access network, while not impacting other traffic type to/from that same UE. Satellite access related efficient user plane requirements are covered in clause 6.46.6. The 5G System shall enable the discovery of a suitable Hosted Service.

Video-based services (e.g. live streaming, VR) and personal data storage applications have been instrumental for the massive growth in mobile broadband traffic. Subject to service agreement between the operator and the content provider, the information of content and content itself can be aware by operator. In-network content caching provided by the operator, a third-party or both, can improve user experience, reduce backhaul resource usage and utilize radio resource efficiently. The operation of in-network caching includes flexible management of the location of the content cache within the network and efficient delivery of content to and from the appropriate content caching application. Examples of services are the delivery of popular video content from a content caching application via broadcast, and secure storage of a user's personal data or files using a distributed caching application. Such a service could also provide a student with a wireless backpack, where students can resume their work through the same or a different UE at any time, with very fast response times from the network.

The 5G system shall enable efficient delivery of content from a content caching application under the control of the operator (e.g. a cache located close to the UE). The 5G system shall support a content caching application in a UE under the control of the operator. The 5G system shall support configurations of content caching applications in the network (e.g. access network, core network), that provide content close to the UE. Based on operator policy, the 5G system shall support an efficient mechanism for selection of a content caching application (e.g. minimize utilization of radio, backhaul resources and/or application resource) for delivery of the cached content to the UE. The 5G system shall support a mechanism for the operator to manage content distribution across content caching applications. The 5G system shall support delivery of cached content from a content caching application via the broadcast/multicast service. For a 5G system with satellite access, the following requirement applies:

• A 5G system with satellite access shall be able to optimise the delivery of content from a content caching application by taking advantage of satellites in supporting ubiquitous service, as well as broadcasting/multicasting on very large to global coverages.

The 5G network will support many commercial services (e.g. medical) and regional or national regulatory services (e.g. MPS, Emergency, Public Safety) with requirements for priority treatment. Some of these services share common QoS characteristics such as latency and packet loss rate but can have different priority requirements. For example, UAV control and air traffic control can have stringent latency and reliability requirements but not necessarily the same priority requirements. In addition, voice-based services for MPS and Emergency share common QoS characteristics as applicable for normal public voice communications yet can have different priority requirements. The 5G network will need to support mechanisms that enable the decoupling of the priority of a particular communication from the associated QoS characteristics such as latency and reliability to allow flexibility to support different priority services (that need to be configurable to meet operator needs, consistent with operator policies and corresponding national and regional regulatory policies). The network needs to support flexible means to make priority decisions based on the state of the network (e.g. during disaster events and network congestion) recognizing that the priority needs can change during a crisis. The priority of any service can be different for a user of that service based on operational needs and regional or national regulations. Therefore, the 5G system should allow a flexible means to prioritise and enforce prioritisation among the services (e.g. MPS, Emergency, medical, Public Safety) and among the users of these services. The traffic prioritisation can be enforced by adjusting resource utilization or pre-empting lower priority traffic. The network must offer means to provide the required QoS (e.g. reliability, latency, and bandwidth) for a service and the ability to prioritize resources when necessary to meet the service requirements. Existing QoS and policy frameworks handle latency and improve reliability by traffic engineering. In order to support 5G service requirements, it is necessary for the 5G network to offer QoS and policy control for reliable communication with latency required for a service and enable the resource adaptations as necessary. The network needs to allow multiple services to coexist, including multiple priority services (e.g. Emergency, MPS and MCS) and must provide means to prevent a single service from consuming or monopolizing all available network resources, or impacting the QoS (e.g. availability) of other services competing for resources on the same network under specific network conditions. For example, it is necessary to prevent certain services (e.g. citizen-to-authority Emergency) sessions from monopolizing all available resources during events such as disaster, emergency, and DDoS attacks from impacting the availability of other priority services such as MPS and MCS. Also, as 5G network is expected to operate in a heterogeneous environment with multiple access technologies, multiple types of UE, etc., it should support a harmonised QoS and policy framework that applies to multiple accesses. Further, for QoS control in EPS only covers RAN and core network, but for 5G network E2E QoS (e.g. RAN, backhaul, core network, network to network interconnect) is needed to achieve the 5G user experience (e.g. ultra-low latency, ultra-high bandwidth).

The 5G system shall allow flexible mechanisms to establish and enforce priority policies among the different services (e.g. MPS, Emergency, medical, Public Safety) and users. The 5G system shall be able to provide the required QoS (e.g. reliability, end-to-end latency, and bandwidth) for a service and support prioritization of resources when necessary for that service. The 5G system shall enable the network operator to define and statically configure a maximum resource assignment for a specific service that can be adjusted based on the network state (e.g. during congestion, disaster, emergency and DDoS events) subject to regional or national regulatory and operator policies. The 5G system shall allow decoupling of the priority of a particular communication from the associated QoS characteristics such as end-to-end latency and reliability. The 5G system shall be able to support a harmonised QoS and policy framework applicable to multiple accesses. The 5G system shall be able to support E2E (e.g. UE to UE) QoS for a service. The 5G system shall be able to support QoS for applications in a Service Hosting Environment. A 5G system with multiple access technologies shall be able to select the combination of access technologies to serve an UE on the basis of the targeted priority, pre-emption, QoS parameters and access technology availability. The 5G system shall support a mechanism to determine suitable QoS parameters for traffic over a satellite backhaul, based e.g. on the latency and bandwidth of the specific backhaul .