Independent Uplink Downlink Handover in LTE Heterogeneous Networks
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Solution Overview
Problem
Current LTE technology faces challenges in optimizing mobility operations, particularly in heterogeneous networks, where handover processes between different cell types (e.g., macro and remote radio heads) are not efficiently decoupled, leading to potential disruptions in communication links and suboptimal resource management.
Innovation Solution
A method is introduced to perform handovers of communication links independently for downlink (DL) and uplink (UL) in LTE networks, allowing for decoupled DL and UL handovers, and optimizing transmit power and timing settings during handovers to maintain continuous connectivity and data integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If coupled handover is used for both uplink and downlink, then handover process is simple and unified, but mobility optimization in heterogeneous networks is limited and disruptions occur
Solution Approach 1:
The patent segments the handover process into independent uplink handover and downlink handover procedures. The UE can perform UL handover to a different cell than DL handover, allowing separate optimization of each link based on independent channel conditions, which resolves the contradiction by enabling efficient mobility while maintaining link continuity through independent control of each communication direction.
2Adaptability or versatility
If independent DL and UL handovers are implemented, then mobility optimization and resource management improve, but handover process complexity increases
Solution Approach 1:
The patent implements dynamic handover configuration where the network can independently control UL and DL handover parameters based on real-time network conditions. The eNodeB can configure different handover conditions, thresholds, and target cells for UL and DL separately, providing adaptability while managing complexity through centralized network control rather than distributed UE decision-making.
Solution Approach 2:
The patent uses preliminary configuration of handover parameters and candidate target cells by the network before actual handover execution. The eNodeB pre-configures UL and DL handover conditions, power control parameters, and timing advance settings, which simplifies the actual handover execution phase while maintaining high adaptability through pre-computed optimization parameters.
3Productivity
If traditional handover is used in heterogeneous networks, then network configuration is simple, but resource management becomes suboptimal and disruptions increase
Solution Approach 1:
The patent applies local quality optimization by allowing different handover parameters, power control settings, and timing configurations for UL and DL based on local channel conditions. The network can optimize handover behavior specifically for each link type (uplink or downlink) based on local network conditions, cell load, and channel quality, achieving superior resource management while handling complexity through localized parameter adjustment rather than global reconfiguration.
Data Source
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AI summary
A method, an apparatus, and a computer program product for wireless communication are provided. In an aspect, the apparatus establishes a first and/or second communication link with at least a first cell. The first communication link may be for receiving transmissions and the second communication link may be for sending transmissions. The apparatus performs a handover of one of the first and second communication links to at least a second cell. The apparatus determines a value of a parameter after the handover is performed based on a value of the parameter prior to the handover. In another aspect, the apparatus establishes a first and/or second communication link with at least a first cell. The first communication link may be for receiving transmissions and the second communication link may be for sending transmissions. In such aspect, a virtual cell ID is reconfigured for one of the first and second communication links.