Synchronizing EUL and HSDPA Cell Change Procedures
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Solution Overview
Problem
The existing mobile communication systems face increased processing loads and excessive radio capacity usage due to separate control procedures and signal transmissions for cell changes in the EUL and HSDPA schemes, and the EUL scheme's physical control signal cannot be time-multiplexed on the HS-DPCCH, leading to quality deterioration in the HSDPA scheme.
Innovation Solution
The mobile communication system synchronizes cell change procedures between the EUL and HSDPA schemes, allowing the serving cells for a mobile station to be modified to the same cell based on received signal levels, and enables time-multiplexing of the EUL scheme's physical control signal on the HS-DPCCH.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate control procedures are implemented for cell changes in EUL and HSDPA schemes, then each scheme can be optimized independently, but the processing load increases and radio capacity is excessively used
Solution Approach 1:
The patent combines the cell change control procedures for EUL and HSDPA schemes into a unified process. The base station determines the serving cell for both EUL and HSDPA simultaneously based on uplink and downlink quality measurements, respectively. This merging eliminates the need for separate independent cell change procedures, thereby reducing processing load and control signal overhead while maintaining optimal performance for both schemes.
2Adaptability or versatility
If EUL scheme's physical control signal is transmitted separately, then it maintains independence, but HSDPA scheme quality deteriorates due to excessive radio capacity usage
Solution Approach 1:
The patent merges the transmission timing of EUL physical control signals with HSDPA downlink data transmission. The base station transmits EUL physical control signals and HSDPA downlink data in the same time slot, utilizing available radio capacity efficiently. This combined transmission approach prevents quality deterioration in HSDPA by avoiding excessive separate transmissions while maintaining the functional independence of EUL control signals.
3Productivity
If cell changes are synchronized between EUL and HSDPA, then control procedure load is reduced, but the system must coordinate multiple quality measurements and decisions
Solution Approach 1:
The base station performs preliminary measurements of both uplink quality (for EUL) and downlink quality (for HSDPA) continuously before cell change decisions are required. By having these measurements ready in advance, the system can make coordinated cell change decisions for both schemes simultaneously without complex real-time coordination, thereby reducing control procedure load while managing the complexity of multi-quality measurements.
Data Source
AI summary
The present invention relates to a mobile communication system which applies a high-speed downlink packet transmission scheme (HSDPA scheme) in a downlink and an enhanced uplink packet transmission scheme (EUL scheme) in a uplink between a mobile station and a base station. In the mobile communication system according to the present invention, a serving cell in the high-speed downlink packet transmission scheme for a specified mobile station and a serving cell in the enhanced uplink packet transmission scheme for the specified mobile station are modified so as to become the same cell.