Cell Reselection in Heterogeneous Networks Using Squal and Srxlev
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems where LTE coexists with GSM, UMTS, and CDMA2000, the ping-pong effect occurs due to inter-RAT cell reselection based on different criteria, leading to unnecessary cell reselections.
Innovation Solution
A method for user equipment to perform cell reselection in LTE systems by checking SIB parameters for Squal-based cell reselection, using Squal measurements if the target RAT supports it and is of a higher or equal version, or falling back to Srxlev measurements if not, ensuring consistent reselection criteria across heterogeneous networks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If inter-RAT cell reselection is performed based on different criteria (Srxlev for older RATs, Squal for LTE), then mobility support between heterogeneous networks is enabled, but ping-pong effect occurs due to inconsistent reselection criteria
Solution Approach 1:
The patent changes the measurement parameter from Srxlev (receive level) to Squal (quality) based on the UE's capability and the target RAT's version. When a UE supports Squal-based measurements and the target RAT version is equal to or higher than the UE's version, the patent applies Squal for cell reselection decisions. This parameter change ensures consistent quality-based reselection across heterogeneous networks, preventing ping-pong effects caused by inconsistent criteria.
2Reliability
If Squal-based cell reselection is used for all RATs, then consistent reselection criteria are achieved, but compatibility with older RATs that do not support Squal is lost
Solution Approach 1:
The patent dynamically selects the reselection measurement type (Squal or Srxlev) based on the target RAT's version and the UE's capability. The selection is not static but adapts to the specific scenario: if the target RAT version is equal to or higher than the UE's version and Squal is supported, then Squal is used; otherwise, Srxlev is used. This dynamic approach ensures both consistency where applicable and compatibility where required.
Solution Approach 2:
The patent changes the measurement parameter from Srxlev to Squal based on the target RAT's version and UE capability. This conditional parameter change allows the system to use the more reliable Squal metric when compatible, while falling back to Srxlev for older RATs that don't support it, thus achieving both consistency and compatibility.
3Adaptability or versatility
If multiple measurement parameters (Srxlev and Squal) are supported for different RATs, then flexibility in cell reselection is improved, but device complexity increases
Solution Approach 1:
The patent implements dynamic selection logic that automatically chooses between Squal and Srxlev based on the target RAT's version and the UE's capability. This dynamic decision-making process, while adding some complexity, is systematic and rule-based, allowing the UE to support multiple parameters without requiring complex manual configuration or intervention.
Data Source
AI summary
The present disclosure provides a method for cell reselection in a wireless communication system in which various radio access technologies (RATs) coexist with each other. In a wireless communication system in which heterogeneous networks coexist with each other, the method of cell reselection between heterogeneous networks for a user equipment may include: receiving a system information block (SIB) containing cell reselection parameters from a corresponding base station; checking whether cell reselection parameters based on a cell selection quality value (Squal) are configured in the received SIB; and performing, when cell reselection parameter based on Squal are not configured, cell reselection based on a cell selection receive level value (Srxlev). The present disclosure may prevent the user equipment from performing unnecessary cell reselection.