Random Access Channel Resource Allocation for MTC UEs

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Solution Overview

Problem

Machine Type Communication (MTC) User Equipment (UE) in LTE/LTE-A systems face challenges in accessing the system due to performance degradation and reduced coverage, especially in environments with penetration loss, necessitating improvements in Physical Random Access Channel (PRACH) and related message processes to ensure reliable access.

Innovation Solution

A method and system for allocating random access channel resources, including configuration of random access channel information through downlink channels, division of MTC UEs into coverage improvement levels, and allocation of time-frequency resources based on these levels to enhance uplink and downlink coverage, using techniques like time division multiplexing (TDM) and frequency division multiplexing (FDM), and configuring random access sequences and retransmissions accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If MTC terminals use low-cost configuration (reducing receiving antennas, baseband processing bandwidth, peak rate), then device cost is reduced, but coverage performance and access quality deteriorate

Engineering Contradiction:

Improvedevice costVSAvoidcoverage performance

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent segments MTC terminals into different groups based on their coverage requirements and channel conditions. By dividing terminals into multiple groups, the system can allocate different PRACH resources to each group, allowing low-cost terminals to access the network reliably without requiring all terminals to have high-performance configurations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by allocating different PRACH configuration parameters (such as different time-frequency resources, different preamble formats, different root sequence indices) to different terminal groups based on their specific coverage needs. This allows each terminal group to use PRACH resources optimized for their local conditions rather than using a uniform configuration for all terminals.

Inventive Principle:

Principle #3Local quality

2Adaptability or versatility

If MTC terminals are located in challenging environments (basement, corner with penetration loss), then device portability and deployment flexibility are improved, but access quality and coverage are reduced

Engineering Contradiction:

Improvedeployment flexibilityVSAvoidaccess quality

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent changes PRACH parameters dynamically based on terminal location and channel conditions. Different PRACH configurations (time resources, frequency resources, preamble formats, root sequence indices) are allocated to terminals in different environments. This allows terminals in challenging locations like basements or corners to use PRACH resources with parameters optimized for their specific propagation conditions, maintaining access quality despite environmental challenges.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If multiple UEs send random access sequences on the same time-frequency resources, then resource utilization efficiency is improved, but random access contention increases

Engineering Contradiction:

Improveresource utilization efficiencyVSAvoidrandom access success rate

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent segments the random access process by allocating different PRACH resources to different terminal groups. This segmentation reduces the number of terminals competing for the same resources, thereby reducing contention while still allowing multiple terminals to share the overall PRACH resources efficiently. Each group experiences reduced contention within its allocated resources.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of having all terminals compete for the same PRACH resources (traditional approach), the patent inverts the approach by having the network allocate different PRACH resources to different terminal groups. This inversion of the resource allocation strategy reduces contention while maintaining efficient resource utilization across the system.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentEP3051897B1Method and system for allocating random access channel resource

Publication Date: 2020.04.01 ZTE CORP

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AI summary

Disclosed are a method and system for allocating random access channel resources, wherein the method includes the following steps: a first node sending random access channel configuration information through a downlink channel, wherein the information includes at least configuration information of a random access channel allocated to a second node. The present invention relates to the field of mobile communication. The technical solution according to the embodiment of the present invention is applicable to a machine type communication (MTC) system, thereby solving the problem of an MTC user equipment (UE) receiving a random access response message, and achieving a receiving configuration of the random access response message in an improvement design.