LTE Frequency Priority Management for VoLTE Message Delivery

Solution Overview

Problem

In LTE networks, Voice over LTE (VoLTE) user equipment (UE) may miss data messages when idling on a different frequency, as the initial frequency selection priority is used for data transmission, leading to missed messages until they are resent over a wider range of frequencies.

Innovation Solution

The LTE wireless access system processes a user Identifier (ID) to select a new frequency band selection priority for UE, transferring a connection release message indicating this new priority, allowing the UE to idle on a different frequency band for a specified time period before reverting to the initial priority, ensuring data messages are routed correctly based on the current frequency band selection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If VoLTE UEs use a different frequency selection priority during idle mode to avoid interference, then communication reliability is improved, but data message delivery fails because the network uses the initial frequency priority to route messages

Engineering Contradiction:

Improvecommunication reliabilityVSAvoiddata message delivery

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The network performs preliminary actions by storing the alternative frequency priority information and timing details before the UE enters idle mode. When the UE returns, the network has already prepared the correct frequency routing information, ensuring messages are delivered on the correct frequency without requiring the UE to be present during the priority switching decision

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary mechanism where the network stores and manages the mapping between UEs and their alternative frequency priorities. This intermediary storage allows the network to recall the correct frequency priority when routing data to UEs returning from idle mode, bridging the gap between the UE's current frequency and the network's routing decisions

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If the network uses the initial frequency selection priority to route data messages to idle UEs, then message routing is simplified, but VoLTE UEs may miss messages when idling on a different frequency

Engineering Contradiction:

Improvemessage routingVSAvoidmessage delivery

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The network performs preliminary actions by storing the alternative frequency priority information and timing details before the UE enters idle mode. When the UE returns, the network has already prepared the correct frequency routing information, ensuring messages are delivered on the correct frequency without requiring the UE to be present during the priority switching decision

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary mechanism where the network stores and manages the mapping between UEs and their alternative frequency priorities. This intermediary storage allows the network to recall the correct frequency priority when routing data to UEs returning from idle mode, bridging the gap between the UE's current frequency and the network's routing decisions

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If VoLTE UEs revert to initial frequency selection priority after a time period, then frequency selection flexibility is improved, but message delivery fails during the transition period when UEs are on different frequencies

Engineering Contradiction:

Improvefrequency selection flexibilityVSAvoidmessage delivery delay

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The network performs preliminary actions by storing the alternative frequency priority information and timing details before the UE enters idle mode. When the UE returns, the network has already prepared the correct frequency routing information, ensuring messages are delivered on the correct frequency without requiring the UE to be present during the priority switching decision

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements feedback mechanisms where the network tracks the idle mode status and frequency priority changes of UEs. This feedback allows the network to dynamically adjust message routing based on the UE's current frequency priority state, preventing message loss during transitions and reducing delivery delays

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS9706538B1Frequency priority based message transfer in long term evolution (LTE) systems

Publication Date: 2017.07.11 T MOBILE INNOVATIONS LLC

AI summary

A Long Term Evolution (LTE) wireless access system transfers wireless data to User Equipment (UE) over a first frequency band based on an initial frequency band selection priority. The LTE wireless access system processes a user Identifier (ID) associated with the UE to select a new frequency band selection priority for the UE. The LTE wireless access system transfers a connection release message to the UE indicating the new frequency band selection priority for the UE. The LTE wireless access system receives a data message for the UE and identifies a second frequency band for the UE based on the new frequency band selection priority. The LTE wireless access system transfers the data message to the UE over the second frequency band.