Multihop Relay Reselection Using PC5 Reuse for Session Continuity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing technologies lack effective relay reselection procedures for maintaining session continuity in multi-hop UE-to-Network relay environments, particularly in scenarios involving link failure or degradation.
Innovation Solution
Implement relay reselection procedures where a UE-to-Network relay or an intermediate relay can establish a new end-to-end connection by reusing existing PC5 connections with child or parent relays, updating IP addresses, and communicating traffic over alternative multihop paths to maintain connectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If relay reselection procedures are implemented to maintain session continuity during link failure or degradation, then service reliability for remote UEs is improved, but system complexity increases due to additional signaling and path management requirements
Solution Approach 1:
The patent establishes end-to-end connections and allocates IP addresses for remote UEs in advance before link failures occur. The U2N relay pre-configures multihop paths through intermediate relays, so that when link failure or degradation is detected, the relay reselection can immediately switch to a pre-established alternative path without disrupting the remote UE's service session.
Solution Approach 2:
The patent introduces intermediate relays as mediators between the remote UE and the U2N relay. These intermediate relays forward traffic and signaling messages along the multihop path, enabling flexible path selection and relay reselection. When a link fails, the U2N relay can select different intermediate relays to form an alternative path, maintaining session continuity without direct intervention from the remote UE.
2Reliability
If alternative multihop paths are established for relay reselection, then connectivity reliability is improved, but signaling overhead increases due to path information exchange and connection management
Solution Approach 1:
The patent merges the relay reselection signaling with existing connection management procedures. The U2N relay uses the same PC5 connection to communicate with intermediate relays for both initial path establishment and relay reselection. Request messages, accept messages, and IP address information are all transmitted over the existing PC5 connection, consolidating multiple signaling functions into a single communication channel and reducing overall signaling overhead.
Solution Approach 2:
The patent reuses the existing PC5 connection between the U2N relay and intermediate relays for relay reselection instead of establishing new connections. The same communication interface and protocol stack are copied and reused for both initial connection setup and relay reselection procedures, eliminating redundant signaling and reducing overhead.
3Reliability
If IP address reuse is implemented during relay reselection, then session continuity is improved, but connection management complexity increases due to path-to-IP address mapping requirements
Solution Approach 1:
The patent implements feedback mechanisms where the U2N relay monitors the quality of links between intermediate relays and continuously evaluates alternative paths. When link degradation or failure is detected, the relay uses stored path information and IP address mappings to quickly select an alternative path and switch traffic routing. The system maintains a mapping between available paths and IP addresses of remote UEs, enabling rapid relay reselection while maintaining session continuity.
Data Source
AI summary
Procedures, methods, architectures, apparatuses, systems, devices, and computer program products for relay reselection in a wireless communication network. A remote user equipment (UE) may establish a multihop connection to a network via one or more intermediate relays and a UE-to-network (U2N) relay. When relay reselection is triggered, an intermediate relay or the U2N relay may check whether there is an existing connection (e.g., a mapping for traffic forwarding exists) for the remote UE. For example, the intermediate relay may decide to reuse the existing connection to the U2N relay for a new path to the remote UE. An IP address of the remote UE may be signaled to other intermediate relays along the new path.