Abstract A loopback testing system for an asynchronously operating fully duplex data transmission path comprising proximate and remote stations, a proximate-to-remote data transmission channel for transmitting data to the remote station at a relatively high maximum data transmission rate, and a remote-to-proximate data transmission channel for transmitting data to the proximate station at a relatively low maximum data transmission rate. A test-waveform generator applies to the proximate station, for transmission along the proximate-to-remote channel, a test waveform presenting a data transmission rate at least approximately equal to the aforementioned higher maximum data transmission rate. A loopback circuit at the remote station receives the thusly transmitted test waveform and reapplies it at the remote station for transmission back to the proximate station along the remote-to-proximate channel. However, the loopback circuit includes a digital frequency divider which reduces the waveform-element transmission rate presented by the test waveform to such a level that the waveform-element duration of the test waveform, as transmitted back to the proximate station, at least approximately corresponds to the aforementioned lower maximum data transmission rate.
In combination with an asynchronously operating fully duplex data transmission path comprising a first and a second station, a first data transmission channel for transmitting data from the first to the second station at a respective first maximum data transmission rate, and a second data transmission channel for transmitting data from the second to the first station at a respective second maximum data transmission rate, the first maximum data transmission rate being at least several times higher than the second maximum data transmission rate, a novel testing system which comprises: means applying to the first station a test waveform for transmission to the second station along said first data transmission channel, the test waveform presenting a data transmission rate at least approximately equal to said first maximum data transmission rate; loopback means at the second station connected to receive the test waveform and applying a return waveform to the second station for transmission to the first station along said second data transmission channel, the loopback means including a binary frequency divider for reducing the waveform-element transmission rate of the test waveform to such a level that the waveform-element duration of the test waveform transmitted back along said second channel at least approximately corresponds to said second maximum data transmission rate.
Claim 2
Dependent Claim
210 words
In combination with an asynchronously operating fully duplex data transmission path comprising a first and a second station, a first data transmission channel for transmitting data from the first to the second station at a respective first maximum data transmission rate, and a second data transmission channel for transmitting data from the second to the first station at a respective second maximum data transmission rate, the first maximum data transmission rate being at least several times higher than the second maximum data transmission rate, a novel testing system which comprises: means applying to the first station a test waveform for transmission to the second station along said first data transmission channel, the test waveform presenting a data transmission rate at least approximately equal to said first maximum data transmission rate; loopback means at the second station connected to receive the test waveform and applying a return waveform to the second station for transmission to the first station along said second data transmission channel, the loopback means including a binary frequency divider for reducing the waveform-element transmission rate of the test waveform to such a level that the waveform-element duration of the test waveform transmitted back along said second channel at least approximately corresponds to said second maximum data transmission rate.