In telecommunication, maximum user signaling rate is the maximum rate, in bits per second, at which binary information can be transferred in a given direction between users over the telecommunications system facilities dedicated to a particular information transfer transaction, under conditions of continuous transmission and no overhead information.

Note 1: For a single channel, the signaling rate is given by where SCSR is the single-channel signaling rate in bits per second, T is the minimum time interval in seconds for which each level must be maintained, and n is the number of significant conditions of modulation of the channel.

Note 2: In the case where an individual end-to-end telecommunications service is provided by parallel channels, the parallel-channel signaling rate is given by where PCSR is the total signaling rate for m channels, m is the number of parallel channels, Ti is the minimum interval between significant instants for the I-th channel, and ni is the number of significant conditions of modulation for the I-th channel.

Note 3: In the case where an end-to-end telecommunications service is provided by tandem channels, the end-to-end signaling rate is the lowest signaling rate among the component channels.

Source: from Federal Standard 1037C