Base Station Random Access Response Scheduling Using C-RNTI and RA-RNTI

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Solution Overview

Problem

Current random access response transmission in wireless communication systems faces inefficiencies due to the limitations of using either C-RNTI or RA-RNTI, where C-RNTI ensures reliability but occupies one resource block, while RA-RNTI allows shared usage but lacks retransmission capability and is time-consuming for address determination.

Innovation Solution

A wireless communication system that employs a scheduler in the base station device to determine whether to use C-RNTI or RA-RNTI for random access response transmission based on downlink traffic and the number of responses, optimizing resource allocation and enabling retransmissions by using identification information allocated for each mobile station device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If C-RNTI is used for random access response transmission, then reliability is improved through retransmission capability, but resource block occupancy increases and transmission efficiency decreases

Engineering Contradiction:
ImprovereliabilityVSAvoidtransmission efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies dynamics by making the identification information selection adaptive rather than fixed. The base station dynamically chooses between C-RNTI and RA-RNTI based on real-time conditions such as downlink traffic volume and the number of random access responses to be transmitted. This dynamic adaptation allows the system to optimize between reliability (using C-RNTI when needed) and transmission efficiency (using RA-RNTI when appropriate), resolving the contradiction between these two parameters.

Inventive Principle:
Principle #15Dynamics

2Productivity

If RA-RNTI is used for random access response transmission, then resource block sharing and transmission efficiency are improved, but retransmission capability is lost and reliability decreases

Engineering Contradiction:
Improvetransmission efficiencyVSAvoidreliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system dynamically adjusts the identification information selection based on downlink traffic conditions and the number of responses to be transmitted. When downlink traffic is light and few responses need transmission, RA-RNTI is used to maximize resource sharing and transmission efficiency. When traffic increases or reliability requirements rise, the system switches to C-RNTI, ensuring retransmission capability. This dynamic behavior resolves the contradiction between transmission efficiency and reliability.

Inventive Principle:
Principle #15Dynamics

3Reliability

If C-RNTI is used for random access response transmission, then retransmission capability is maintained, but the time required for address determination increases

Engineering Contradiction:
Improveretransmission capabilityVSAvoidaddress determination time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements dynamic selection of identification information based on the number of random access responses to be transmitted. When only one response needs to be sent, C-RNTI is used to maintain retransmission capability with acceptable time overhead. When multiple responses need transmission, the system switches to RA-RNTI to reduce address determination time and improve efficiency. This dynamic approach balances retransmission capability requirements with time constraints.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2159939B1Base station device, mobile station device, wireless communication system, program, random access response transmitting method, and random access response receiving method
Publication Date: 2018.01.31 SHARP KK
  • EP2159939B1 patent drawingFigure 1
  • EP2159939B1 patent drawingFigure 2
  • EP2159939B1 patent drawingFigure 3

AI summary

A base station device includes: a random access identification information storage that stores random access identification information and mobile station device identification information correlated with the random access identification information, the random access identification information being allocated by the base station device to the mobile station device, and the mobile station device identification information identifying the mobile station device; a random access receiver that receives random access identification information transmitted by the mobile station device performing random access; a scheduler that, if the random access identification information received is stored in the random access identification information storage while being correlated with the mobile station device identification information, determines whether to transmit random access response information that is a response to the random access corresponding to the random access identification information received by using the mobile station device identification information, or by using identification information having not been allocated to a specific mobile station device, the identification information being allocated for transmitting the response to the random access; and a transmitter that allocates and transmits the random access response information based on the determination by the scheduler.