EP-4478639-B1 - WIRELESS TERMINAL APPARATUS, FIRE ALARM

EP4478639B1EP 4478639 B1EP4478639 B1EP 4478639B1EP-4478639-B1

Inventors

SUGAWARA, TAKAYUKI
NAGAI, SHOJI
AOYAMA, KEIICHI
MORINO, MAKOTO
HAKATA, Shogo
MIYAKE, TAKAAKI
OOUCHIDA, Hiroshi

Dates

Publication Date: 20260513
Application Date: 20240611

Claims (4)

A wireless terminal apparatus (200) comprising: a communication unit (210) that performs a transmission operation for transmitting a notification signal to a communication target apparatus (100) and a reception operation for receiving a response signal transmitted from the communication target apparatus (100) receiving the notification signal; and a battery (220) for causing the communication unit (210) to operate, wherein the communication unit (210) performs a retransmission operation for retransmitting the notification signal and the reception operation when the communication unit (212) fails to receive the response signal, and wherein the communication unit (210) is configured such that: 1) when a number of times of failure to receive the response signal reaches a specified number of times, the communication unit (210) continues to retransmit the notification signal but stops the reception operation; or 2) the communication unit (210) performs a combination of the retransmission operation and the reception operation up to a first number of times provided that a number of times of failure to receive the response signal so far has not reached a specified number of times, and the communication unit (210) changes the first number of times to a second number of times smaller than the first number of times when a number of times of failure to receive the response signal reaches a specified number of times.
The wireless terminal apparatus (200) according to claim 1, wherein the communication unit (210) performs the transmission operation and the reception operation periodically, wherein the communication unit (210) performs the retransmission operation and the reception operation when the communication unit (210) fails to receive the response signal in response to the notification signal transmitted periodically provided that the number of times of failure to receive the response signal so far has not reached the specified number of times, and wherein the communication unit (210) performs the retransmission operation and stops the reception operation when the communication unit (210) fails to receive the response signal in response to the notification signal transmitted periodically provided that the number of times of failure to receive the response signal so far has reached the specified number of times.
The wireless terminal apparatus (200) according to claim 2, wherein the specified number of times to determine to stop the reception operation is defined as a first specified number of times, and a second specified number of times larger than the first specified number of times is also defined, and wherein the communication unit (210) also stops the transmission operation when the number of times of failure to receive the response signal reaches the second specified number of times.
The wireless terminal apparatus (200) according to claim 3, further comprising: a user operation unit (218) that receives a user operation from outside, wherein the user operation (218) resumes at least one of the transmission operation or the reception operation when the user operation unit (218) receives the user operation.

Description

[TECHNICAL FIELD] The present disclosure relates to communication technology and, particularly to a wireless terminal apparatus and a fire alarm that receive a response to a signal when the signal is transmitted. [BACKGROUND ART] An alarm system for detecting an abnormality such as heat and smoke generated in a room, etc. includes a plurality of alarms. The alarm system performs an alarm operation in conjunction with each other by bidirectional communication between a plurality of alarms. In the alarm system, a confirmation is made to see whether any abnormality has occurred, by periodically exchanging signals between a plurality of alarms during monitoring. To reduce the power consumed in periodic transmission in which signals are periodically exchanged between a plurality of alarms during monitoring, a communication abnormality is confirmed when a signal cannot be received over a certain period of time (see, for example, Patent Literature 1). Document "ALICE: Autonomous Link-based Cell Scheduling for TSCH", (KIM SEOHYANG ET AL, 2019 18TH ACM/IEEE INTERNATIONAL CONFERENCE ON INFORMATION PROCESSING IN SENSOR NETWORKS, pages 121-132) discloses an autonomous link-based cell scheduling scheme. US 2014/122956 A1 discloses a message retransmission apparatus. [RELATED-ART LITERATURE] [PATENT LITERATURE] [Patent Literature 1] JP2012-88957 [SUMMARY OF INVENTION] [TECHNICAL PROBLEM] In an alarm system capable of bidirectional communication, a plurality of battery-powered alarms (fire alarms) are, for example, connected to a gateway driven by a power supply, and the gateway performs wireless communication with each fire alarm. In the aforementioned periodic transmission, the fire alarm periodically transmits a notification signal (status notification signal) to the gateway, and the gateway that receives the notification signal transmits a response signal to the fire alarm. When the fire alarm does not receive the response signal from the gateway that the notification signal is sent to, the fire alarm retransmits the notification signal. When retransmission of the notification signal is repeated, the power consumption of the fire alarm will increase, and the battery life will be shortened. When retransmission of the notification signal is stopped to reduce the power consumption, on the other hand, the reliability of the alarm system will decrease. The present disclosure addresses the issue described above, and a purpose thereof is to provide a technology that suppresses a decrease in reliability while reducing the power consumption at the same time. [SOLUTION TO PROBLEM] A wireless terminal apparatus according to the present invention is defined in independent claim 1. Preferred embodiments are defined in dependent claims 2 to 4. [ADVANTAGEOUS EFFECTS OF INVENTION] According to the present disclosure, it is possible to suppress a decrease in reliability while reducing the power consumption at the same time. [BRIEF DESCRIPTION OF THE DRAWINGS] Embodiments will now be described by way of examples only, with reference to the accompanying drawings which are meant to be exemplary, not limiting and wherein like elements are numbered alike in several Figures in which: Fig. 1 shows a configuration of an alarm system according to exemplary embodiment 1;Fig. 2 shows a configuration of the fire alarm of Fig. 1;Figs. 3A-3B show an outline of an operation of the alarm system of Fig. 1;Figs. 4A-4B show an outline of another operation of the alarm system of Fig. 1;Fig. 5 is a flowchart showing steps of an operation performed by the fire alarm of Fig. 2;Fig. 6 shows an outline of an operation in the alarm system according to exemplary embodiment 2;Fig. 7 shows an outline of an operation in the alarm system according to exemplary embodiment 3; andFig. 8 shows an outline of an operation in the alarm system according to exemplary embodiment 4. [DESCRIPTION OF EMBODIMENTS] (Exemplary embodiment 1) A brief summary will be given before describing the present disclosure in specific details. The embodiment relates to an alarm system provided in a facility such as a multi-unit apartment building, an independent housing, an office, and a hospital. In the alarm system, a plurality of fire alarms are connected to a gateway. The gateway performs wireless communication with each fire alarm. When the fire alarm detects an outbreak of a fire, the fire alarm transmits a result of detection to the gateway. When the result of detection is received, the gateway selects one or more fire alarms that should output an alarm and transmits an instruction to output an alarm to the one or more selected fire alarms. The fire alarm outputs an alarm when the fire alarm receives the instruction to output an alarm. In order to confirm whether an abnormality has occurred in such an alarm system, the fire alarm periodically transmits a notification signal to the gateway, as described above, and the gateway receiving the notification signal transmits a response signal