Two sets of Philips Avent Video Baby Monitors can operate independently in the same area without any interference. Each set of baby monitors will automatically take the channel for each baby unit and parent unit.
It is important to note that using two devices are not possible if you are only using one parent unit with two baby units.
Note: If there is any connection interference while using the two devices, the baby monitors may be too close to other devices that are interfering on the same frequency because of the wireless connection. Other devices can include smartphones, tablets, laptop, or even microwaves. Try different locations or turn off other devices and test again.