Autonomous Fast Return Mechanism for Wireless RAT Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless communications systems experience long delay times when switching between different radio access technologies (RATs), such as switching from 4G to 3G/2G, which degrades user experience and communication performance.
Innovation Solution
A communications apparatus and method that utilizes an autonomous fast return (AFR) mechanism, involving a processor-controlled RF and baseband signal processing device to maintain an AFR list of cell selection/reselection parameters, switch between RATs, establish and release connections, and perform cell selection or redirection procedures to quickly return to a preferred RAT.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a communications apparatus switches between different RATs using conventional procedures, then compatibility with existing systems is maintained, but long delay time occurs during switching
Solution Approach 1:
The patent applies preliminary action by pre-collecting and storing cell selection/reselection parameters of the first RAT in an AFR list before switching to the second RAT. When the connection is released, the apparatus can immediately perform cell selection or redirection using the pre-stored parameters, avoiding time-consuming parameter collection during the return process. This resolves the contradiction by preparing necessary information in advance, enabling fast return while maintaining system compatibility.
2Reliability
If general cell reselection procedures are performed to return to the original RAT, then proper cell selection is ensured, but time-consuming operations increase the delay
Solution Approach 1:
The patent segments the cell selection process by dividing parameters into two categories: essential parameters stored in the AFR list for immediate use, and optional parameters that can be collected later. This segmentation allows the apparatus to perform a simplified cell selection using pre-stored essential parameters, achieving both speed and reliability. The segmented approach resolves the contradiction by separating time-critical operations from less time-sensitive operations.
Solution Approach 2:
The patent uses copying by storing copies of cell selection/reselection parameters in the AFR list before switching RATs. These parameter copies enable the apparatus to perform cell selection without retrieving original parameters from the network during the return process. This copying mechanism resolves the contradiction by having ready-made parameter copies that ensure accurate cell selection while eliminating time-consuming parameter retrieval operations.
3Stability of the object's composition
If the apparatus maintains connection with the second RAT for extended period, then connection stability is improved, but the ability to quickly return to preferred RAT is reduced
Solution Approach 1:
The patent applies preliminary action by pre-collecting cell selection parameters of the first RAT and storing them in the AFR list during the connection phase. This preliminary preparation ensures that when the connection needs to be released, the apparatus can immediately initiate fast return procedures using the pre-stored parameters. This resolves the contradiction by preparing return parameters in advance, allowing the apparatus to maintain stable connection when needed while enabling rapid return when required.
Data Source
AI summary
A communications apparatus includes an RF signal processing device, a baseband signal processing device and a processor. The processor controls operations of the RF signal processing device and the baseband signal processing device, camps on a first cell of a first RAT, collects cell selection/reselection parameters of one or more frequencies of the first RAT in an autonomous fast return (AFR) list, switches from the first RAT to the second RAT to camp on a second cell of the second RAT, establishes a connection with a peer communications apparatus via the second cell, receives a connection release message or a channel release message from the second cell to release the connection, and switches from the second RAT to the first RAT by performing a cell selection procedure or a redirection procedure according to the AFR list to camp on a third cell of the first RAT.