Dynamic Uplink Control Channel Assignment for Radio Resource Efficiency

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Solution Overview

Problem

The existing method for assigning dedicated control channels in the uplink of a radio communication system results in inefficient use of radio resources, as channels are allocated even during periods when control signals are not used, leading to waste.

Innovation Solution

The proposed solution involves optimizing channel assignment based on the type of uplink control signal, using a combination of contention-based common control channels, pre-assigned-type shared control channels, and data channels, ensuring channels are allocated only during active communication periods and associating control channels with data channels for efficient resource utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a dedicated control channel is assigned to each user terminal during connection, then collision-free control signal transmission is achieved, but radio resource use efficiency deteriorates due to continuous allocation even when control signals are not transmitted

Engineering Contradiction:
Improvecontrol signal transmission reliabilityVSAvoidradio resource waste
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The control channel assignment is made dynamic rather than static. The base station determines whether to assign a dedicated control channel based on real-time transmission needs. When a user terminal has data to transmit, a dedicated control channel is assigned; when no transmission is needed, the assignment is released. This dynamic adjustment resolves the contradiction between ensuring reliable collision-free transmission and avoiding radio resource waste during idle periods.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the parameter of channel assignment from a fixed state (always assigned during connection) to a variable state (assigned only when needed). The base station monitors the transmission status of user terminals and adjusts the control channel assignment parameter accordingly, assigning dedicated channels only when control signals need to be transmitted, thereby eliminating waste while maintaining reliability when needed.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If dedicated control channels are continuously assigned during connection periods, then control signal transmission is ensured, but channel utilization efficiency deteriorates due to idle allocation periods

Engineering Contradiction:
Improvecontrol signal transmission assuranceVSAvoidchannel utilization efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The control channel assignment operates dynamically based on actual transmission requirements. The base station monitors whether user terminals have data to transmit and adjusts channel assignments in real-time. This dynamic approach ensures that control channels are allocated only during periods when control signals need to be transmitted, thereby improving channel utilization efficiency while maintaining transmission assurance when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system extracts the control channel assignment from the continuous connection period and isolates it to only the periods when control signals are actually transmitted. By separating the channel allocation from the entire connection duration and limiting it to active transmission periods only, the system improves channel utilization efficiency while preserving the reliability of control signal transmission when required.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If dedicated control channels are assigned to all connected users, then collision avoidance is achieved, but radio resource waste increases during periods without control signal transmission

Engineering Contradiction:
Improvecollision-free transmissionVSAvoidradio resource waste
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The system implements dynamic control channel assignment where the base station determines allocation based on actual transmission needs. When multiple users are connected but none have control signals to transmit, no dedicated channels are assigned. When users do have data to transmit, dedicated control channels are assigned to prevent collisions. This dynamic approach eliminates radio resource waste during idle periods while maintaining collision-free transmission when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The channel assignment parameter changes from a static always-assigned state to a variable state based on transmission activity. The base station monitors the data transmission status of connected users and adjusts the control channel assignment parameter accordingly, allocating dedicated channels only to users who have data to transmit, thereby preventing both collision and radio resource waste.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP1892975B2Channel assignment method, radio communication system, base station apparatus and user terminal
Publication Date: 2018.01.31 NTT DOCOMO INC
  • EP1892975B2 patent drawingFigure 1
  • EP1892975B2 patent drawingFigure 2
  • EP1892975B2 patent drawingFigure 3

AI summary

In a radio communication system, a user terminal transmits a reservation packet to a base station using a common control channel (1), and the base station assigns an uplink data channel to the user terminal according to the reservation packet, and assigns a first shared control channel (2b) to the user terminal in association with the uplink data channel, and the mobile station transmits a control signal to the base station using the associated uplink shared control channel. According to status of radio communication, the base station may assign beforehand a second uplink shared control channel (2a) for which occupation by the user terminal is permitted only while the user terminal is performing communication.