An alert device includes electronic circuitry and at least a first antenna. The circuitry is designed for sending out a first signal, for wireless communication with at least a first hand held communication device, and at least a second signal for wireless communication with at least a second hand held communication device. The second signal differs from the first signal, preferably in at least one of transmitting energy, transmitting frequency, coding and pulse length. The device includes a switch for switching between: a first mode in which only the first signal is transmitted and a second mode wherein the first and second signal are transmitted; or a first mode wherein only the first signal is transmitted and a second mode wherein only the second signal is transmitted.

An alert device includes electronic circuitry and at least a first antenna. The circuitry is designed for sending out a first signal, for wireless communication with at least a first hand held communication device, and at least a second signal for wireless communication with at least a second hand held communication device. The second signal differs from the first signal, preferably in at least one of transmitting energy, transmitting frequency, coding and pulse length. The device includes a switch for switching between: a first mode in which only the first signal is transmitted and a second mode wherein the first and second signal are transmitted; or a first mode wherein only the first signal is transmitted and a second mode wherein only the second signal is transmitted.

Doorbells can send data to each other to enable a first doorbell user to warn a second doorbell user regarding a suspicious visitor. A first user can indicate a first trait of a visitor via a first remote computing device. The first user can create a user group to enable the members of the user group to use their doorbells to take pictures of suspicious visitors and to send the pictures of the suspicious visitors to other members of the user group.

Doorbell systems can include a speaker and a visitor detection system that includes at least one of a button, a camera, and a motion detector. Doorbell systems can be configured to detect an identity of a visitor via facial recognition, initiate a communication session with a remote computing device, and send the identity to the remote computing device via the first communication session.

A controller doorbell circuit includes a first terminal of a button wired to a first terminal of a transformer, a second terminal of the transformer wired to an input transformer terminal of a controller wired to a battery power source and coupled in signal communication to a mobile device, a transformer terminal of a signaling device wired to an output transformer terminal of the controller, and a second terminal of the button and an alarm terminal of the signaling device wired to an alarm terminal of the controller. The controller opens disabling the controller doorbell circuit disabling the signaling device from sounding an alarm when the button is pressed, in response to a first signal from the mobile device. The controller closes enabling the controller doorbell circuit enabling the signaling device to sound the alarm when the button is pressed, in response to a second signal from the mobile device.

Systems and methods for volume control over intercom trunk lines. One example method includes receiving, from a first keypanel coupled to a first intercom, a call request identifying a remote keypanel coupled to a second intercom. The method includes transmitting a trunk request based on the call request and receiving a trunk setup message. The method includes activating a first crosspoint to provide a two-way audio connection between the first and second intercom devices. The method includes applying a trunk gain value to the first crosspoint based on the remote keypanel and transmitting, with an audio gain based on the trunk gain value, an audio stream received from the first keypanel. The method includes receiving, from the second intercom, a gain adjustment value associated with the first keypanel and the remote keypanel and applying an adjusted trunk gain value to the first crosspoint based on the gain adjustment value.

Systems and methods for volume control over intercom trunk lines. One example method includes receiving, from a first keypanel coupled to a first intercom, a call request identifying a remote keypanel coupled to a second intercom. The method includes transmitting a trunk request based on the call request and receiving a trunk setup message. The method includes activating a first crosspoint to provide a two-way audio connection between the first and second intercom devices. The method includes applying a trunk gain value to the first crosspoint based on the remote keypanel and transmitting, with an audio gain based on the trunk gain value, an audio stream received from the first keypanel. The method includes receiving, from the second intercom, a gain adjustment value associated with the first keypanel and the remote keypanel and applying an adjusted trunk gain value to the first crosspoint based on the gain adjustment value.

Devices, methods, and systems for mass notification are described herein. One method includes receiving, by an operator station, a selection associated with a particular paging group of a fire network associated with a facility, receiving an audio message by the operator station, and communicating the audio message to the particular paging group according to the selection.

A doorbell system can include a doorbell and a chime. The chime can emit a notification sound in response to a visitor pressing a button of the doorbell. Electrical switches can be electrically coupled between the doorbell and the chime to control the flow of electricity to the chime. In some embodiments, the switches prevent the chime from emitting notification sounds.

A method of detecting and responding to a visitor to a smart home environment via an electronic greeting system of the smart home environment, including determining that a visitor is approaching an entryway of the smart home environment; initiating a facial recognition operation while the visitor is approaching the entryway; initiating an observation window in response to the determination that a visitor is approaching the entryway; obtaining context information from one or more sensors of the smart home environment during the observation window; and at the end of the time window, initiating a response to the detected approach of the visitor based on the context information and/or an outcome of the facial recognition operation.