Various communication systems may benefit from an improved signaling protocol. For example, communication systems may benefit from an improved network support for a single frequency network transmission using an Ethernet switch. A method includes receiving a message at an access point in a single frequency network from a network entity through a data switch. The message comprises an indication of at least one of a downlink physical channel or an uplink physical channel. The method also includes transmitting a request for a signal characteristic through the at least one downlink physical channel to a user equipment. In addition, the method includes receiving the signal characteristic through the at least one uplink physical channel from the user equipment. Further, the method includes transmitting a response message through the data switch from the access point to the network entity indicating the signal characteristic.