Cellular Scheduler for Delay-Tolerant and Sensitive Session Coexistence

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Solution Overview

Problem

Existing Machine-Type Communication (MTC) systems face challenges in coexisting delay-tolerant and delay-sensitive sessions, as hard-slicing reduces system capacity and soft-slicing complicates resource management, making it difficult to guarantee quality of service for critical communications while supporting massive connectivity.

Innovation Solution

A scheduler in a cellular communications system identifies available resources and determines link adaptation parameters for delay-tolerant transmissions to enable delay-sensitive communications by predicting puncturing probabilities, allowing for resource reassignment and adaptive link adaptation to prioritize delay-critical sessions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hard-slicing is used to reserve frequency resources for C-MTC service, then reliability of C-MTC communication is improved, but system capacity is reduced

Engineering Contradiction:
Improvereliability of C-MTC communicationVSAvoidsystem capacity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent implements dynamic resource allocation where the network node determines puncturing probabilities for delay-tolerant transmissions based on current system conditions. Resources are dynamically reassigned from delay-tolerant to delay-sensitive sessions when needed, allowing the system to adapt between hard-slicing (high reliability) and soft-slicing (high capacity) modes based on real-time traffic demands and service requirements.

Inventive Principle:
Principle #15Dynamics

2Productivity

If soft-slicing is used to share frequency resources dynamically, then system capacity is improved, but quality of service guarantee for C-MTC becomes difficult

Engineering Contradiction:
Improvesystem capacityVSAvoidquality of service guarantee for C-MTC
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The network node performs preliminary determination of puncturing probabilities for delay-tolerant transmissions before actual resource allocation. By predicting the likelihood of puncturing in advance, the system can pre-adjust link adaptation parameters and prepare appropriate redundancy levels, ensuring that even when resources are dynamically reassigned to delay-sensitive traffic, the quality of service for delay-tolerant sessions remains acceptable.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes link adaptation parameters (such as modulation and coding schemes, redundancy levels) based on determined puncturing probabilities. When puncturing probability is high, more robust parameters are selected to maintain reliable communication despite potential resource reassignment. This dynamic parameter adjustment allows soft-slicing to function while maintaining quality of service guarantees for delay-tolerant C-MTC communications.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If M-MTC transmissions are scheduled over most frequency resources with long transmission intervals, then coverage is improved, but resource availability for C-MTC sessions is reduced

Engineering Contradiction:
Improvecoverage for M-MTCVSAvoidresource availability duration for C-MTC
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system dynamically determines puncturing probabilities for M-MTC transmissions based on the presence and requirements of C-MTC sessions. When C-MTC traffic is detected, the network node can increase the puncturing probability for scheduled M-MTC resources, allowing rapid reassignment to time-critical C-MTC sessions. This dynamic approach enables M-MTC to maintain coverage through repetition while ensuring C-MTC can access resources immediately when needed.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3284297B1Improved coexistence of delay-tolerant and delay-sensitive sessions
Publication Date: 2019.12.18 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3284297B1 patent drawingFigure 1
  • EP3284297B1 patent drawingFigure 2
  • EP3284297B1 patent drawingFigure 3

AI summary

A method of operation of a scheduler implemented in a network node of a cellular communications system comprises scheduling one or more delay- tolerant transmissions by one or more respective wireless devices in a subframe. Scheduling the one or more delay-tolerant transmissions by the one or more respective wireless devices comprises, for each wireless device: identifying a plurality of available resources in a subframe; for each available resource of the plurality of available resources in the subframe, determining one or more link adaptation parameters for the wireless device for the available resource based on information representing a statistical model of predicted puncturing of delay- tolerant transmissions using the available resource in order to enable transmission of delay-sensitive transmissions; and selecting one of the plurality of available resources in the subframe for the delay-tolerant transmission of the wireless device based on at least one of the one or more link adaptation parameters.