Relay Selection for Multicast Broadcast Service in 5G Sidelink
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current 3GPP technical specifications lack a mechanism to combine multicast broadcast services (MBS) with sidelink relay in 5G/NR mobile communication systems, limiting the ability of remote user equipment outside a base station's coverage to receive MBS data effectively.
Innovation Solution
A communication method that involves selecting a suitable relay user equipment to transfer MBS data from a base station to a remote user equipment, including steps such as receiving interest information, establishing or resuming an RRC connection, and performing handover processing to ensure seamless data transfer even when the relay user equipment changes cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a remote user equipment outside base station coverage attempts to receive MBS data directly, then the base station coverage area is limited, but the remote user equipment cannot receive MBS data reliably
Solution Approach 1:
The patent introduces a relay user equipment as an intermediary node between the base station and remote user equipment. The relay UE receives MBS data from the base station via Uu interface and forwards it to the remote UE via sidelink, enabling reliable MBS data reception for users outside direct base station coverage while maintaining multicast efficiency.
2Adaptability or versatility
If multiple relay user equipments are available for MBS data transfer, then the selection process becomes complex, but the remote user equipment needs to select the most suitable relay
Solution Approach 1:
The patent implements a feedback mechanism where the remote user equipment sends interest information to candidate relay UEs, and relay UEs respond with their capability status regarding the desired MBS session. This structured feedback exchange enables the remote UE to identify suitable relay UEs without requiring complex evaluation of all possible relays.
3Speed
If the relay user equipment changes cells during MBS data transfer, then the data transfer continuity is disrupted, but the relay user equipment needs to perform handover
Solution Approach 1:
The patent implements preliminary actions before handover by causing the remote user equipment to transmit measurement reports to the base station when handover of the relay UE is determined. The base station then performs handover of the remote UE before the relay UE handover, ensuring seamless data transfer continuity across cell boundaries.
4Use of energy by moving object
If the relay user equipment is in RRC idle or inactive state, then the connection establishment overhead is reduced, but the relay cannot receive MBS data from base station
Solution Approach 1:
The patent implements dynamic state transitions where the relay user equipment transitions from RRC idle or inactive state to RRC connected state upon receiving interest information from a remote UE. This dynamic adaptation allows the relay to maintain low power consumption when not needed while ensuring full MBS data reception capability when required.
Data Source
AI summary
A communication method for transmitting multicast broadcast service (MBS) data belonging to an MBS session from a base station to a remote user equipment via a relay user equipment, the method including a step of selecting, by a remote user equipment, a relay user equipment configured to transfer a desired MBS session in preference to a relay user equipment configured not to transfer the desired MBS session, the remote user equipment being interested in receiving the desired MBS session, and a step of receiving, by the remote user equipment, MBS data belonging to the desired MBS session from a base station via the selected relay user equipment.