CBSD Frequency Transition Management for CBRS Service Continuity
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Solution Overview
Problem
Current CBRS architectures lack mechanisms for maintaining service continuity during frequency changes, leading to disruptions and long delays in re-attachment of Consumer Premises Equipment (CPE) to the Citizens Broadband Radio Service Device (CBSD) due to the SAS's inability to associate CPE with CBSD/eNB effectively.
Innovation Solution
The method involves communicating data between CBSD/xNB and attached CPE to cause the CPE to wait a prescribed period before re-attaching, using the SAS-designated new channel for direct re-attachment, thereby minimizing disruption and maintaining service continuity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the SAS reassigns frequency carriers to CBSD/xNB, then spectrum utilization and adaptability are improved, but service continuity deteriorates due to CPE re-attachment delays
Solution Approach 1:
The system performs preliminary actions by notifying CPE of upcoming frequency changes before they occur. The CPE is provided with advance information about the new frequency and timing, allowing it to prepare for the transition. This preliminary notification enables the CPE to switch frequencies proactively rather than reactively, maintaining service continuity during spectrum reassignment.
Solution Approach 2:
The system implements feedback mechanisms where the CBSD/xNB communicates frequency change information back to the CPE. This feedback loop allows the CPE to receive real-time or near-real-time information about frequency reassignments, enabling it to adjust its frequency tuning and re-attachment timing accordingly, thus maintaining reliable service during dynamic spectrum management.
2Measurement precision
If the CPE performs full band scans to detect CBSD/xNB, then frequency detection accuracy is improved, but re-attachment time increases significantly
Solution Approach 1:
The CBSD/xNB provides preliminary information to the CPE about the new frequency assignment before the CPE needs to re-attach. This advance notification eliminates the need for the CPE to perform exhaustive full band scans, as it already knows which frequency to tune to. The CPE can directly transition to the specified frequency, achieving both accurate frequency detection and minimal re-attachment time.
Solution Approach 2:
The system extracts only the necessary frequency information from the full spectrum and communicates it directly to the CPE. Instead of requiring the CPE to search through the entire frequency band, the system provides the specific frequency assignment information, allowing the CPE to jump directly to the correct frequency without unnecessary scanning, thus reducing re-attachment time while maintaining detection accuracy.
3Productivity
If the SAS manages frequency assignments centrally, then spectrum allocation efficiency is improved, but system complexity increases due to CPE-CBSD association management
Solution Approach 1:
The CBSD/xNB acts as an intermediary between the SAS and the CPE in frequency management. The SAS provides high-level frequency assignment directives to the CBSD/xNB, which then handles the specific communication with the CPE regarding frequency changes. This intermediary role simplifies the SAS's burden by delegating association management tasks to the CBSD/xNB, maintaining efficient centralised spectrum allocation while reducing overall system complexity.
Data Source
AI summary
Methods and apparatus for managing frequency reassignment within wireless access nodes so as to minimize data session disruption. In one embodiment, the frequency reassignments occur within a quasi-licensed system utilizing 3.5 GHz CBRS (Citizens Broadband Radio Service) spectrum, and a reassignment of wireless spectrum that mitigates disruption or loss of continuity to existing data sessions of users of devices associated with a CBSD/xNB is provided via notification of the associated devices (e.g., Category B Consumer Premises Equipment or CPE, such as an FWA) of the reassignment by the CBSD/xNB. In one variant, the associated devices are instructed by the CBSD/xNB to invoke a “wait and re-establish” protocol that obviates a full frequency band rescan in favor of a designated target frequency provided to the CBSD/xNB by the cognizant SAS or DP.