DRX-Aligned Access for Low-Power D2D Devices

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Solution Overview

Problem

In device-to-device (D2D) communication, low-capability devices face high power consumption and performance issues due to complex random access processes when accessing high-capability devices, leading to short working times and resource conflicts.

Innovation Solution

Implementing a method where low-capability devices access high-capability devices during predetermined moments aligned with the discontinuous reception (DRX) cycle of the high-capability device, reducing frequent wake-ups and allowing multiple devices to access simultaneously, thereby reducing power consumption and conserving network resources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the second device accesses the first device using the random access manner (contention-based or non-contention based), then the second device can establish network connection, but power consumption of the second device is high and working time is short

Engineering Contradiction:
Improvenetwork connection establishmentVSAvoidpower consumption of second device
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The network side device pre-configures access configuration information including predetermined moments and access resources for the second device. This preliminary configuration allows the second device to access the first device at predetermined moments without performing complex random access procedures, thereby reducing power consumption while ensuring reliable network connection establishment.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If the first device frequently wakes up to wait for access from the second device, then the second device can access the first device, but power consumption of the first device increases

Engineering Contradiction:
Improveaccess availabilityVSAvoidpower consumption of first device
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The system implements periodic access at predetermined moments that are aligned with the DRX cycle of the first device. The second device is configured to access the first device at these predetermined moments, allowing the first device to remain in low-power state between periods while ensuring access availability when needed.

Inventive Principle:
Principle #19Periodic action

3Adaptability or versatility

If multiple second devices access the first device simultaneously using random access, then network resource scheduling is required, but this increases system complexity and resource overhead

Engineering Contradiction:
Improvemulti-device access capabilityVSAvoidnetwork scheduling complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system segments the access process by dividing multiple second devices into different access groups, with each group assigned to specific predetermined moments and access resources. This segmentation allows multiple devices to access simultaneously without requiring complex centralized scheduling, as each device independently follows its assigned access pattern.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3358885B1User access device and user equipment
Publication Date: 2021.02.03 HUAWEI TECH CO LTD
  • EP3358885B1 patent drawingFigure 1~2
  • EP3358885B1 patent drawingFigure 3~4B
  • EP3358885B1 patent drawingFigure 5~6

AI summary

Embodiments of the present invention provide a user access method and user equipment. A second device communicates with a first device at a predetermined moment so as to access the first device, where the predetermined moment is determined according to a DRX cycle of the first device. In this process, the predetermined moment is determined according to the DRX cycle of the first device, and the second device communicates with the first device at the predetermined moment so as to access the first device, so that the second device accesses the first device.