Proximity Join using Bluetooth and ultrasound

Proximity Join is a feature that lets end users use the Teams app on a desktop or mobile device to invite or nudge a Microsoft Teams Room into a Teams meeting. The Teams Room doesn't need to be invited to the meeting to be joined using proximity join. Proximity join is also a requirement to enable Room Remote functionality. This feature uses wireless technologies that can be individually turned on or off based on the requirements of the environment:

• Bluetooth
• Ultrasound (Ultrasonic)

The end user experience is the same using either Bluetooth or ultrasound for Proximity Join. If they're both turned on, they operate together to provide improved accuracy. A Teams Room that is found using ultrasound on is always put at the top of the list of nearby rooms in the meeting's prejoin screen (under the room audio option). Teams Rooms that are found using Bluetooth are listed after the rooms that have ultrasound turned on.

When a user's laptop or mobile device brings a Teams Rooms in using Proximity Join or if Proximity Join detects a user is joining while in a Teams Room which is already in the same meeting, the user's video won't appear on the room's display, and the room's video stream is hidden on the personal device meeting stage. Users can override the automatic hiding behavior by using the pin or spotlight functionality of Teams Meetings.

Proximity Join nudges from a desktop or mobile client must come from a user within the same tenant or from a trusted external organization. Users not covered by these scenarios won't see the Teams Room available for proximity join.

Proximity join doesn't require a direct network connection between a user personal devices and the Teams Rooms device, all communication takes place through Microsoft Teams.

Bluetooth

Bluetooth is a short range wireless technology in which compatible devices can use it to communicate. However, this signal can penetrate through walls. Rooms discovered through Bluetooth are sorted by signal strength in descending order, and it includes all Teams Rooms both in use and not in use. This is because the Bluetooth signal isn't paused when Microsoft Teams Room has joined a meeting.

Bluetooth must be enabled on both the Teams Rooms device and on the client desktop/mobile endpoint in order for proximity to function.

For information on the security of Bluetooth Proximity Join see Teams Rooms Security.

Ultrasound

Ultrasound signaling is available on Microsoft Teams Rooms on Windows (from compatible consoles) and can be used to along with Bluetooth for more accurate proximity join logic.

The Proximity Join using ultrasound works by emitting an ultrasonic (19.5 kHz - 21.5 kHz) signal from the Teams Room console that isn't audible to humans. It's more accurate than Bluetooth because at reasonable volume, it won't penetrate through walls but the signal is paused when the Microsoft Teams Room is either in a meeting or HDMI ingest is active. For example, you walk into a conference room with ultrasound turned on the Teams Rooms console, and you want to join your meeting to the Teams Room, you see it in the meeting's prejoin screen in the list of available rooms because those rooms are sorted and listed at the top of the screen. This lets someone select the exact Teams Rooms console and conference room they want to use for their meeting.

Ultrasound supported devices

Administration and settings

There are multiple ways and tools you can use to manage Proximity Join settings for Microsoft Teams Rooms.