5G • 5G-Advanced (Rel-18)
Coordinated Sidelink Mode 2
Inter-UE Collaborative Resource Allocation for Autonomous V2X
Vehicles autonomously exchange preferred and non-preferred resource reservation sets, preventing hidden-node collisions without base station oversight.
Technical Explanation
In autonomous Sidelink Mode 2, vehicles select transmission slots without base station intervention, which causes packet collisions when two vehicles choose the same slot. Rel-18 Coordinated Mode 2 allows UE-A to broadcast a preferred or non-preferred resource set to UE-B, ensuring neighboring vehicles select mutually orthogonal transmission slots.
Key Functions
- Enables neighboring vehicles to coordinate autonomous spectrum slot selections
- Eliminates destructive packet collisions in dense intersections and highway jams
- Operates fully autonomously in remote rural areas lacking cellular network towers
- Dramatically improves V2X safety message reliability for emergency braking events
Specifications
3GPP TS 38.214, TS 38.331 (Rel-18)
Interfaces
PC5 (SCI Format 2-C)
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