The tactile and multi-modal communication service can be applied in multiple fields, e.g. industry, robotics and telepresence, virtual reality, augmented reality, healthcare, road traffic, serious gaming, education, culture and smart grid . These services support applications enabling input from more than one sources and/or output to more than one destinations to convey information more effectively. As Figure 6.43.1-1 illustrates, the input and output can be different modalities including:
Information received by sensors about the environment, e.g. brightness, temperature, humidity, etc.;
Haptic data: can be feelings when touching a surface (e.g., pressure, texture, vibration, temperature), or kinaesthetic senses (e.g. gravity, pull forces, sense of position awareness).
For immersive multi-modal VR applications, synchronization between different media components is critical in order to avoid having a negative impact on the user experience (i.e. viewers detecting lack of synchronization), particularly when the synchronization threshold between two or more modalities is less than the latency KPI for the application. Example synchronization thresholds  are summarised in Table 6.43.1-1.
The 5G system shall enable an authorized 3rd party to provide policy(ies) for flows associated with an application. The policy may contain e.g. the set of UEs and data flows, the expected QoS handling and associated triggering events, other coordination information.
The 5G system shall support a means to apply 3rd party provided policy(ies) for flows associated with an application. The policy may contain e.g. the set of UEs and data flows, the expected QoS handling and associated triggering events, other coordination information.
Roaming value-added services (RVAS) form part of the roaming services ecosystem and have traditionally been provided by either the PLMN or outsourced to a fully trusted entity. The RVAS provider acting on behalf of the PLMN could be any trusted 3rd party. The RVAS described here are all RVAS enabled by the PLMN for 5GS roaming.
The "Welcome SMS" service sends a SMS to a roaming subscriber's UE when the UE is registered in a new network for the first time. The SMS typically follows a predefined template and is sent on behalf of the home operator and may contain relevant information related to the visited country, e.g., the cost to call home, how to reach the operator's customer service, local emergency services number, etc.
The "Steering of Roaming (SoR) during the registration procedure" service makes the home operator able to steer a user to a certain network during the registration procedure when the user tries to register to a new (non-preferred) network.
The "Subscription-based routing to a particular core network" service forwards the traffic from the HPLMN to a target PLMN. Some operators use more than one PLMN ID, e.g., multi-national operators. Due to certain business and operational demands, it might be necessary to route traffic of a certain customer segment, typically from a certain IMSI range of USIMs, of a PLMN to another PLMN and to further handle the subscriber there. This means the UE is not handled by the "real" HPLMN (according to MNC and MCC) but by some alternative PLMN.
This subscription-based routing enables the case where several national subsidiaries of a multi-national operator offer various services for different customer segments but for operational efficiency the actual service for a certain group is provided by only one dedicated network.
The 5G system shall be able to support mechanisms for the HPLMN to provide a notification, including equipment and subscription identifiers, to a trusted application server when a UE successfully registers in a VPLMN. In response to the notification, the trusted application server can indicate specific actions to the HPLMN (e.g., send an SMS to the UE).
The 5G system shall be able to support a mechanism such that all traffic pertaining to UEs of specific subscribers which is sent to the HPLMN is forwarded to a target PLMN, e.g., to enable further handling of those UEs by the target PLMN. The forwarding mechanism shall minimize traffic in the HPLMN, e.g., by using efficient means to forward traffic from selected UEs.
In the roaming ecosystem, a roaming services provider provides the technical and commercial means to facilitate the deployment and operation of roaming services between a client operator and a set of selected connected operators.
The roaming services provider handles the technical implementation of the roaming relations in a scalable and operationally efficient way.
With a roaming services provider present in the roaming ecosystem, operators can choose not to establish a bilateral direct agreement with specific operators. A trusted relation exists between the involved operator and the roaming services provider.
Roaming services providers, according to their role and responsibilities, assume financial and technical liability to apply all necessary controls and access to all communications.
Among other functionalities, a roaming services provider needs to:
Process identifiers and potentially other information transmitted in signalling messages between PLMNs in a secure manner.
Be able to modify, add or delete information that is relevant to their role, respecting what is contractually agreed in service level agreements (SLAs) and enforced technically.
Isolate the individual operator signalling flows from each other
Report on the detection of and mitigation of security breaches.
The 5G system shall allow roaming services to be provided by a roaming services provider in charge of managing roaming agreements, by mediating between two or more PLMNs, while maintaining the privacy and 5G security of any information transmitted between the home and the serving PLMN.
The 5G system shall allow a roaming services provider to be a trusted entity for either a home PLMN, a visited PLMN or both.
The 5G system shall allow a roaming services provider to accept or reject registration attempts, on behalf of the involved PLMNs, based on the roaming agreements.
The 5G system shall allow a roaming services provider to identify the origin and destination PLMN, and to verify the authenticity, of every transmitted message.
The 5G system shall allow the Roaming services provider to be able to originate and modify messages as per contractually agreed SLAs.
The 5G system shall allow the involved PLMNs to be able to identify the origin of any message generated by the roaming services providers as well as to identify any modification made to the exchanged messages by the roaming services providers.