Description
Objective: The objective of this activity is to design, develop and test a 5G system to support upper layer Access Traffic Switching, Steering and Splitting (ATSSS) mechanisms relating a User Equipment (UE) data session across dual terrestrial and satellite 5G access, as well as over dual 5G satellite access.Targeted Improvements:- Enable dual 3GPP access- Significant part reduction - Network and device centric system- Enable 5G Core Network with an embedded application function (AF) for traffic related policy deduction- Optimisation of multipath transmission protocols.Description: Convergence of multiple radio access technologies such as terrestrial 5G and satellite bearers, is one of the key enablers in providing a diverse set of features to 5G and Beyond 5G (B5G) network users. Multi access (MA) connectivity can offer network resilience, seamless connectivity, traffic offloading, and bonding thus improving user experience and service reliability, essential features for critical, emergency response and vehicular communications. Currently, MA connectivity is mainly achieved through intelligent routing devices; that is proprietary Software Defined Wide Area Network (SD-WAN) developments, built on top of proprietary hardware platforms and deployed in addition to the existing end user devices and Core network infrastructure. This implies an additional layer of complexity on the hybrid connectivity fabric, which currentlymakes it impractical and costly. The introduction of MA-PDU (Multi access Protocol Data Unit) by 3GPP (Third Generation PartnershipProject) in Release 16, and its enhancement as part of Release 17, challenges this issue, by enabling the so-called Access Traffic Steering-Switching-Splitting (ATSSS) feature, in which both 3GPP access (e.g., 5G access) and non-3GPP radio access technologies (RATs) can be used simultaneously. In the current studies, the satellite element is considered as a non 3GPP RAT. However, the integration of satellite access into 3GPP release 17 specifications dictates the development of novel ATSSS solutions where both terrestrialand satellite bearers, implement 5G (3GPP compliant) Access. Therefore, the proposed activity will develop and test a novel 5G system to support upper layer ATSSS mechanisms relating a UE data session across two or more 3GPP RATs, namely dual terrestrial and satellite 5G access or dual 5G satellite access over LEO and GEO links. The main tasks to be delivered are the following:1) Architectural adaptations to 5G Core Network and 5G User Equipment to support ATSSS enabled 5G terrestrial-satellite access;2) Implement the Performance Measurement Function (PMF), both at UE and core network side;3) Develop a 5G Core Application Function (AF) to deduce ATSSS decision policies;4) Compare and optimise upper- and lower-layer multipath transmission protocols (ATSSS-LL, MPTCP, MPDCCP).The results and lessons learnt of this work, will provide inputs to the 3GPP relative standardisation working groups that are currently scoping the subject as part of System Architecture (SA), services and requirements working group - (SA1). The activity will seek synergies with ARTES SPL 5G deliverables and testbeds related to the subject.