You have raised an excellent question.
Short answer: You will need a separation. From experience with GSM/3G/Wireline/etc.. I always have a separation.
An Erlang is a unit of telecommunications traffic measurement and it
basically represents the continuous use of one Voice circuit / connection.
Erlang has it’s connection with the early days of Voice Telephony services.
Lets look at a quick example. If a group of user made 30 calls in one hour, and each call had an
average call duration of 5 minutes, then the number of Erlangs this represents is worked out as follows:-
Minutes of traffic in the hour = number of calls x duration
Minutes of traffic in the hour = 30 x 5 = 150
Hours of traffic in the hour = 150 / 60 = 2.5
Traffic figure= 2.5 Erlangs
For blocking we can use ErlangB – this is another topic.
For your case I would have a separation of Voice and Data.
-Erlangs (or mErlangs) can be used for your GSM/3G/4G Voice.
-Number of SMSs/MMSs Hour for SMS/MMS services. Information can be derived from your
SMS-SC / MMS-SC.
-Data (Mobile Broadband and PCRF): Use the information from your SCP (Diameter Requests)
Please let me know if you need any further information.
VBR/ Wallis Dudhnath