Uplink Switching for Dual Connectivity Mobile Stations
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Solution Overview
Problem
In LTE communication systems, dual connectivity scenarios pose challenges for mobile stations that are not capable of simultaneous uplink transmissions to multiple base stations, leading to inefficiencies in subframe utilization and potential collisions, which affect communication quality and throughput.
Innovation Solution
The method involves coordinating uplink transmissions in the time domain by defining specific subframes for communication with each base station, using an uplink transmission pattern to determine usable subframes for each communication link, and employing a retransmission protocol like HARQ to manage data transfer effectively, even when dual uplink is not supported.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a mobile station is configured for dual connectivity with multiple base stations, then communication capacity and network coverage are improved, but subframe collision and transmission coordination complexity increase when the mobile station cannot perform simultaneous uplink transmissions
Solution Approach 1:
The uplink subframes are segmented and assigned to different base stations through uplink transmission patterns. Each base station is configured with specific subframes for uplink reception, preventing simultaneous uplink transmission conflicts. The network side divides the uplink resource timeline into distinct segments for each connection, allowing dual connectivity without requiring simultaneous transmission capability at the mobile station.
2Reliability
If uplink transmission patterns are configured for each base station, then subframe collision is reduced, but signaling overhead and configuration complexity increase
Solution Approach 1:
Multiple uplink transmission patterns for different base stations are merged into a single composite uplink transmission pattern. The network side combines the subframe allocation information for both base stations into one unified pattern that the mobile station can process. This reduces the number of separate signaling messages required while maintaining the collision avoidance benefits of individual patterns.
3Productivity
If the mobile station supports dual uplink transmission, then uplink throughput is improved, but device capability requirements and power consumption increase
Solution Approach 1:
The system dynamically adapts to the mobile station's transmission capability. When dual uplink is not supported, the network configures separate subframes for each base station, and the mobile station transmits sequentially in different time slots. This dynamic time-division approach allows the system to maintain dual connectivity benefits without requiring the mobile station to simultaneously transmit on both uplinks, thereby reducing power consumption and hardware requirements.
Data Source
AI summary
The invention relates to a method for configuring subframes for uplink/downlink communication for a mobile station (UE) not supporting dual uplink but located in a communication system supporting dual connectivity. The UE is connected simultaneously to two base stations via a respective communication link. An uplink transmission pattern is determined, defining whether subframes are usable for uplink communication to the first or second base station or for switching the uplink communication between the two communication links. Based on the determined uplink transmission pattern, and further based on configuration of the mobile station for supporting dual reception or not, a downlink reception is derived for downlink communication between the two base stations and the mobile station, the downlink reception pattern defining whether the subframes are usable for downlink communication from the first or second base station or for switching the downlink communication between the two communication links.