SUL Carrier Switching for Wireless Uplink Interruption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems, the performance degradation of uplink communication due to the power disparity between user equipment (UE) and base stations leads to reduced cell coverage, especially at the edge of cells, necessitating the use of supplementary uplink (SUL) with lower frequencies to enhance communication reliability.
Innovation Solution
A method and apparatus that register a user terminal using a normal uplink (NUL) carrier, receive configuration information for an SUL carrier, and switch to it when NUL configuration information is not received for a specified period, performing a random access channel (RACH) procedure using the SUL carrier to maintain communication integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If normal uplink (NUL) carrier is used for uplink communication, then transmission speed and data rate are improved, but cell coverage and communication reliability deteriorate at cell edge due to power disparity
Solution Approach 1:
The uplink carrier is segmented into two types: NUL carrier for high-speed data transmission and SUL carrier for extended coverage. The system divides the uplink frequency resources into normal uplink frequencies (e.g., 3.5 GHz) for speed and supplementary uplink frequencies (e.g., 1.8 GHz) for coverage, allowing UE to select appropriate carrier based on channel conditions
Solution Approach 2:
The system changes the frequency parameter of the uplink carrier dynamically. When channel conditions are good, NUL carrier at higher frequency is used for speed. When channel conditions deteriorate (e.g., at cell edge), the system switches to SUL carrier at lower frequency to improve coverage and reliability, thus changing the operating frequency parameter based on channel quality
2Reliability
If SUL carrier is used to extend cell coverage, then communication reliability is improved, but transmission speed and data rate deteriorate due to lower frequency
Solution Approach 1:
The system dynamically switches between NUL and SUL carriers based on real-time channel conditions and UE location. The network configures both carriers for UE and dynamically selects which carrier to use for uplink transmission, making the system adaptive to changing conditions rather than static
3Reliability
If UE switches to SUL carrier when NUL configuration information is unavailable, then connection loss is reduced, but device complexity increases due to carrier management
Solution Approach 1:
The network performs preliminary configuration by providing both NUL and SUL carrier parameters to UE in advance through RRC signaling. This preliminary action prepares UE with all necessary information before actual carrier switching is needed, reducing the complexity of real-time decision-making at UE
Solution Approach 2:
The system implements feedback mechanisms where UE monitors NUL configuration information reception status and channel conditions, then provides feedback to the network. Based on this feedback, the network adjusts carrier configuration and switching decisions, creating a closed-loop control system that manages complexity through coordinated interaction
Data Source
AI summary
A method for enhancing communication interruption using supplementary uplink (SUL) in a wireless communication system includes: registering a user terminal at a cell using a normal uplink (NUL) carrier; receiving configuration information of a SUL carrier from the cell; identifying whether uplink configuration information on the NUL carrier is not received for a specified period of time; based on the uplink configuration information on the NUL carrier not being received for the specified period of time, setting the SUL carrier to be used as an uplink carrier; and performing a random access channel (RACH) procedure using the SUL carrier.