A&D AND TM-2657P Instruction Manual page 46

For good wireless communication
Warning
Do not use in the vicinity of cell phones. This could cause malfunction.
NOTE
Ensure wireless device is within view of the monitor. Wireless range is affected by
building structure and obstructions. Specifically, reinforced concrete can cause
wireless interference.
For the Bluetooth connection, do not use the monitor around wireless LAN, other
wireless applications and the devices that radiate electromagnetic waves such as
microwave ovens, or in location with many obstructions or other environment subject to
weaker radio wave signals.
There is a possibility that the wireless connection may break up frequently, the
communication speed may fall to an extremely low level, or a communication error
occurs.
If the monitor is used near a wireless IEEE802.11g/b/n LAN device, both devices may
generate a radio interference which could decrease wireless speed or break the
wireless connection. In this case, change the location of use or stop using immediately.
If the monitor cannot normally transmit data near a radio or broadcast station, please
change the location.
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