MBSFN Subframe Handover Signaling for Cellular Delay Reduction
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Solution Overview
Problem
Current LTE handover procedures experience delays and failures, especially when user equipment transitions to small cells at high speeds, due to the need for minimizing handover delay and accommodating heterogeneous network mobility.
Innovation Solution
The technique involves transmitting handover-related signaling in Multicast Broadcast Single Frequency Network (MBSFN) subframes by the target node to reduce handover delay, allowing UE-specific information to be delivered directly to the user equipment before it transitions, thereby initiating the handover process earlier and reducing signaling overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If standard LTE handover procedure is used, then handover signaling is delivered through source node, but handover delay increases and handover failures occur
Solution Approach 1:
The patent introduces MBSFN subframes as an intermediary channel for direct handover signaling transmission from target node to UE. This mediator bypasses the traditional source node routing, enabling direct delivery of handover commands and reducing dependency on source node signaling paths, thereby reducing handover delay and improving success rate
Solution Approach 2:
The patent enables target node to transmit handover signaling in advance through MBSFN subframes before the UE actually needs to switch cells. By preparing and delivering handover commands proactively, the system reduces the reactive handover delay and allows UE to prepare for handover earlier, improving both speed and reliability
2Productivity
If handover signaling is transmitted through source node, then signaling protocol is standardized, but signaling overhead increases and handover delay increases
Solution Approach 1:
The patent extracts the handover signaling function from the traditional source node-mediated path and relocates it directly to the target node-to-UE communication channel via MBSFN subframes. This separation removes unnecessary intermediate signaling steps and reduces signaling overhead while accelerating handover execution
3Reliability
If mobility parameters are adjusted to compensate for UE speed, then handover reliability improves for high-speed UE, but system complexity increases and not all parameters can be adjusted fast enough
Solution Approach 1:
The patent enables the target node to autonomously transmit handover signaling directly to UE through MBSFN subframes without requiring complex coordinated adjustments of multiple mobility parameters across source and target nodes. This self-service approach simplifies the system by eliminating the need for intricate parameter tuning while maintaining reliability for high-speed scenarios
Data Source
AI summary
A method of handover signaling in a cellular communication system is disclosed. Prior to a user equipment (UE) undergoing a cell-to-cell transition, a target node transmits handover-related signaling in one or more Multicast Broadcast Single Frequency Network (M8SFN) subframes in order to reduce handover delay. The cellular communication system includes a source node configured to transfer a handover (HO) request to the target node. The (HO) request corresponds to a (UE) presently being served by the source node. The target node is configured to transmit (HO) information to the (UE) over at least one MBSFN subframe in response to the (HO) request.