Half-Duplex Base Station Downlink Message Grouping

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Solution Overview

Problem

Bidirectional ultra-narrowband wireless communication systems face challenges in minimizing the duration for which base stations are unavailable for reception, especially when using half-duplex base stations that cannot receive and transmit simultaneously, leading to potential missed uplink messages.

Innovation Solution

The method involves determining overlap in listening windows of terminals to group downlink messages for transmission by a single base station, extending the listening window duration to at least five times the downlink message duration, and optimizing transmission windows to reduce toggling between reception and transmission modes, allowing for simultaneous or successive transmission of downlink messages at different center frequencies or bit rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If base stations transmit downlink messages within transmission windows, then downlink communication is enabled, but base stations cannot receive uplink messages during these windows

Engineering Contradiction:

Improvedownlink communication capabilityVSAvoiduplink message reception

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The system performs preliminary actions by having terminals transmit uplink messages before the base station enters transmission mode. The base station receives and stores uplink messages in advance, then transmits downlink messages in the predetermined transmission window. This sequencing ensures that uplink messages are captured before the base station becomes unavailable for reception.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The base station operates in periodic cycles, alternating between reception mode (for uplink messages) and transmission mode (for downlink messages). This periodic switching creates predictable transmission windows where downlink messages are sent, and reception windows where uplink messages are received, resolving the contradiction by making the unavailability periodic rather than continuous.

Inventive Principle:

Principle #19Periodic action

2Adaptability or versatility

If base stations frequently switch between reception and transmission modes, then bidirectional communication is supported, but the duration of unavailability for reception increases

Engineering Contradiction:

Improvebidirectional communicationVSAvoidreception unavailability duration

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The system merges multiple downlink messages into a single transmission window, allowing the base station to send multiple messages to different terminals simultaneously or in sequence within one unavailability period. This reduces the frequency of mode switching and minimizes the total time the base station is unavailable for reception.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The base station uses excessive action by allocating a transmission window that is longer than the minimum required for downlink message transmission. This excess capacity allows multiple downlink messages to be bundled together, reducing the number of separate transmission windows needed and thereby reducing overall reception unavailability.

Inventive Principle:

Principle #16Partial or excessive action

3Reliability

If terminals listen for downlink messages during extended listening windows, then downlink message reception reliability increases, but power consumption increases

Engineering Contradiction:

Improvedownlink message receptionVSAvoidterminal power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

Terminals perform preliminary actions by transmitting uplink messages and then entering a known listening window based on predetermined timing relationships. This allows terminals to know exactly when to activate their receivers, avoiding continuous listening and reducing power consumption while ensuring they are listening during the transmission window when downlink messages arrive.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Terminals use periodic action by activating their receivers only during predetermined listening windows and remaining in standby mode otherwise. This periodic activation pattern ensures reliable downlink message reception during the listening window while minimizing power consumption by keeping the receiver off during standby periods.

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS10333665B2Method and system for wireless communication between terminals and half-duplex base stations

Publication Date: 2019.06.25 UNABIZ SAS

AI summary

A wireless communication method between a plurality of terminals and an access network. The access network is configured to transmit downlink messages on a downlink in reply to uplink messages transmitted by the terminals. The access network includes a plurality of half-duplex base stations. Each terminal waiting for a downlink message in reply to a transmitted uplink message is configured to listen to the downlink in a listening window, the duration of which is at least five times that of the downlink message. The method includes the steps of determining if listening windows of terminals overlap. When an overlap allows the transmission of several downlink messages by a single base station, the downlink messages are transmitted grouped together in a single transmission window of the base station.