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© MiMOMax 2013 Four Wire Audio
Interface Manual
2.6
L
ATENCY
End-to-end latency is a combination of audio processing plus Radio Unit latency which is
dependent on Radio Unit RF bandwidth and modulation settings.
Latency introduced by the Radio Units is dependent on the applied RF parameters. As an
example radios with settings of 25 kHz and 16 QAM would provide an additional latency of
6ms. For a complete list please refer to the ‘MiMOMax Radio Installation and Operation
Guide’.
Four Wire Audio interface unit Latency
(As would be achieved by direct connection between two Four Wire Audio interface units).
Audio latency
:
< 6ms (end-to-end audio delay for active channel)
E&M latency
:
< 6ms (end-to-end delay for change of state)
Data latency
:
< 1ms (end-to-end data delay)
Note:
E&M Latency includes a de-bounce delay of 5ms where the E-Lead signal must be in
a steady state for 5ms for that state to be recognised. Therefore audio will not be passed until
the transition from inactive to active is recognised. Similarly audio will continue to be passed
until the transition from active to inactive is recognised.
Adding the FWA interfaces and Radio Units latency figures will give an overall end-to-end
latency.
As an example FWA interfaces connected to Radio Units set to 25 kHz and 16 QAM would
provide the following.
Audio latency
:
12 ms or better.
EIA232 latency
:
7 ms or better (NOTE: independent of interface word
timings).
For Radio Units set up with Power on Demand (M-PoD) additional start up delays will be
experienced as the Air Interface is brought up. For further details please refer to the
‘MiMOMax Radio Installation and Operation Guide’.
