Intelligent CSFB Management for LTE Voice Data Sessions

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Solution Overview

Problem

Current LTE networks experience significant delays and user experience degradation due to interruptions during circuit switched fallback (CSFB) from LTE to 3G networks for voice calls, resulting in 4-second interruptions to fallback to 3G and 12-second interruptions to return to LTE for data sessions.

Innovation Solution

Implementing a method to determine the priority of voice call requests compared to ongoing data sessions, allowing for intelligent management of CSFB by redirecting voice calls based on priority, thereby minimizing interruptions and maintaining data sessions on LTE networks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If circuit switched fallback is implemented to enable simultaneous voice and data sessions, then voice call capability is improved, but network interruption time increases

Engineering Contradiction:

Improvevoice call capabilityVSAvoidnetwork interruption time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent changes the network architecture parameter from traditional CSFB to Voice over LTE (VoLTE), enabling voice calls to operate natively on the LTE packet-switched network. This eliminates the need to fall back to 3G circuit-switched networks, thereby resolving the contradiction by maintaining voice capability while avoiding network interruptions and preserving data session continuity.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If fallback to 3G network is performed for voice calls, then voice service is maintained, but data session continuity deteriorates

Engineering Contradiction:

Improvevoice serviceVSAvoiddata session continuity

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent merges voice and data services into a single LTE packet-switched network infrastructure. By implementing VoLTE, both voice calls and data sessions can coexist simultaneously on the same network without requiring fallback to 3G, thus maintaining data session continuity while providing reliable voice service.

Inventive Principle:

Principle #5Merging (Combining)

3Adaptability or versatility

If CSFB is used to handle incoming voice calls, then call acceptance is improved, but user experience deteriorates due to interruptions

Engineering Contradiction:

Improvecall acceptanceVSAvoiduser experience

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent transitions from CSFB architecture to VoLTE architecture, changing the fundamental parameter of how voice calls are handled. This allows incoming voice calls to be accepted and routed directly through the LTE network without causing service interruptions, thereby improving user experience while maintaining call acceptance capability.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS8862090B2Intelligent long term evolution circuit switched fallback management

Publication Date: 2014.10.14 AT&T INTELLECTUAL PROPERTY I L P

AI summary

A device may connect a data session for a wireless transmit/receive unit (WTRU) to a long term evolution network and during the data session receive a voice call request for the WTRU. In addition the device may prioritize the voice call request compared to the data session and direct the voice call to a network device based on the prioritization.