LTE Coverage-Extension Mode for MTC Devices

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Solution Overview

Problem

Long-term Evolution (LTE) networks face significant overhead and latency issues when supporting coverage-limited Machine Type Communications (MTC) devices, particularly in scenarios like smart metering where devices are installed in basements or shielded locations, leading to substantial penetration loss and increased transmission times.

Innovation Solution

Implementing a coverage-extension mode during low-traffic periods, allowing MTC devices to access the system with reduced system information and skipping certain steps in the connection procedure, such as random access and RRC configuration, while maintaining previous configurations for previously connected UEs, and using new channels or repetitions only when necessary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional LTE connection procedures are used for coverage-limited MTC devices, then connection reliability is improved, but overhead and latency increase significantly

Engineering Contradiction:

Improveconnection reliabilityVSAvoidlatency

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The network pre-configures and stores RRC configuration information for coverage-limited MTC devices before they need to connect. When a device needs to establish a connection, it can retrieve the pre-configured parameters immediately without undergoing the full RRC configuration procedure, thereby reducing latency while maintaining connection reliability through proven configuration parameters.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The connection procedure is segmented into essential steps only. Coverage-limited MTC devices skip non-essential steps such as random access and full RRC configuration, proceeding directly to data transmission using pre-configured parameters. This segmentation reduces overhead and latency while maintaining the critical functions needed for reliable connection.

Inventive Principle:

Principle #1Segmentation

2Reliability

If conventional LTE connection procedures are used for coverage-limited MTC devices, then connection reliability is improved, but system overhead increases

Engineering Contradiction:

Improveconnection reliabilityVSAvoidsystem overhead

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The invention extracts and removes non-essential steps from the conventional LTE connection procedure for coverage-limited MTC devices. Specifically, the random access procedure and full RRC configuration steps are taken out, leaving only the essential data transmission steps. This reduces system overhead in terms of signaling messages and processing resources while maintaining connection reliability through pre-configured parameters.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of performing the complete connection procedure, the system applies partial action by executing only the necessary steps for MTC devices. The random access and RRC configuration steps are omitted, and devices jump directly to data transmission using pre-configured parameters. This partial execution reduces overhead while providing sufficient functionality for MTC applications.

Inventive Principle:

Principle #16Partial or excessive action

3Area of stationary object

If transmission power is increased to extend coverage, then coverage range is improved, but energy consumption increases

Engineering Contradiction:

Improvecoverage rangeVSAvoidenergy consumption

Core Design Contradiction:

Area of stationary objectVSUse of energy by moving object

Solution Approach 1:

RRC configuration parameters including transmission power settings are pre-configured and stored in the network before MTC devices need to connect. This allows coverage-limited devices to use optimized power levels determined in advance, avoiding the need to continuously increase power to extend coverage, thereby reducing energy consumption while maintaining extended coverage capability.

Inventive Principle:

Principle #10Preliminary action

4Reliability

If random access and RRC configuration steps are included in connection procedure, then connection reliability is improved, but latency and overhead increase

Engineering Contradiction:

Improveconnection reliabilityVSAvoidlatency

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

RRC configuration information is pre-configured and stored in the network before MTC devices need to connect. When a device needs to establish a connection, it retrieves the pre-configured parameters immediately without undergoing the full RRC configuration procedure, thereby reducing latency while maintaining connection reliability through proven configuration parameters.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentEP3020229B1Operating coverage-limited devices

Publication Date: 2020.08.05 NOKIA SOLUTIONS & NETWORKS OY

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AI summary

A method and apparatus can be configured to operate a node in a first mode (210) to support one or more user equipment. The method can also include operating the node in a second mode (220) to support one or more user equipment. The coverage of the second mode is enhanced compared to the coverage of the first mode.