LTE VoIP Semi-Persistent Scheduling Activation via ROHC State
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Solution Overview
Problem
Current communication systems, particularly in LTE and HSPA networks, lack a mechanism for activating and deactivating semi-persistent scheduling (SPS) for VoIP services, leading to inefficiencies due to the absence of defined triggering conditions and mechanisms for uplink and downlink SPS based on the state of the eNB ROHC decompressor and compressor.
Innovation Solution
A method is introduced to determine the operational state of the header compressor or decompressor, triggering changes in persistent scheduling modes by activating or deactivating uplink and downlink SPS during talk periods or silence periods based on transitions between different operational states, such as from a first order to a second order state or from a static to a full context state, and de-allocating resource blocks as needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If semi-persistent scheduling is activated for VoIP services, then resource allocation efficiency is improved, but system complexity increases due to lack of defined activation and deactivation mechanisms
Solution Approach 1:
The patent applies parameter changes by monitoring the operational state parameters of the ROHC compressor (such as context state, packet size, header compression ratio) and transitioning between different scheduling modes (dynamic scheduling vs. semi-persistent scheduling) based on these parameter thresholds. This resolves the contradiction by providing clear parameter-based triggers for SPS activation/deactivation, improving resource efficiency while maintaining manageable system complexity through defined state transition criteria.
2Adaptability or versatility
If dynamic scheduling is used for each VoIP packet, then adaptability to traffic conditions is improved, but overhead increases due to continuous PDCCH resource allocation
Solution Approach 1:
The patent implements periodic action by transitioning to semi-persistent scheduling where resource allocations are made periodically rather than dynamically for every packet. Once SPS is activated based on initial traffic analysis, the system uses pre-configured resource allocations for subsequent packets during active voice sessions, significantly reducing PDCCH overhead. The system periodically re-evaluates traffic conditions to determine whether to maintain SPS or revert to dynamic scheduling, thus balancing overhead reduction with traffic adaptability.
3Quantity of substance
If semi-persistent scheduling is deactivated, then resource overhead is reduced, but resource allocation efficiency deteriorates during active voice sessions
Solution Approach 1:
The patent employs feedback mechanisms by continuously monitoring the operational state of the ROHC compressor and decompressor, including context state transitions, packet size variations, and voice activity detection. This feedback information is used to make intelligent decisions about SPS activation and deactivation timing. The system activates SPS when compression efficiency improves and traffic patterns stabilize, and deactivates when context is lost or traffic becomes unpredictable, thus minimizing overhead while maintaining high resource allocation efficiency during beneficial periods.
Data Source
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AI summary
A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus determines an operational state of a header compressor or a header decompressor by determining a transition between different operational states associated with the header compressor and/or by determining a transition between different operational states associated with the header decompressor. A persistent scheduling mode is changed in response to a change in the operational state of the header compressor. The persistent scheduling mode may be changed by activating uplink persistent scheduling when the operational state of the header compressor changes from a first order state to a second order state, and/or by deactivating the uplink persistent scheduling when the operational state of the header compressor exits the second order state.