ITU R.21:1996
ITU R.21:1996 9600 Bit/s Modem Standardized For Use In The Telegraph Tdm System This Recommendation gives a definition of a modem for using in telegraph TDM systems.
Table of Contents
1Scope2Normativereferences
3Linesignalstructure
4Requirementstoreceivedsignalsfrequencytolerance
5Transmittedpowerlevels
6Modulationmethodandsignalspacediagram
7Datasignallingandmodulationrates
8Receivedsignalconditions
9Interchangecircuits
10Synchronization
11Specialmeasuresforraisingmodemimmunity
12TestingFacilities