In one telephone network, traffic load in one day (24 hour) very varies. This variation very ascertained especially by location or area factor where the telephone network exist and observation time (morning, midday, night, holiday, workday, etc).
Generally, for time interval midnight until six o’clock, network utilization is very low because is a rest time (sleep). Traffic peak is occurring in midday (ten o’clock until eleven o’clock) and after lunch period (fifteen o’clock until sixteen o’clock) because office hour bustle. Between seventeen o’clock until nineteen o’clock traffic relative low because on the way time period from work place to home. Domestic call peak generally occur after nineteen o’clock, after telephone costumer to stay in home and possibility of charge reduction from local telecommunication service provider.
As long as holiday or feast day (holy day), traffic form usually different. Generally, traffic peak occur around nine o’clock, at the same moment before telephone users leaving their home to go and next traffic peak is afternoon when they already to go home.
In one day, high traffic in 60 minute time interval, is called busy hour. 1-hour (60 minute) period between ten o’clock until eleven 0’clock, is busy hour. Because busy hour can varies between one central with another central depend on location and local community, then to calculating this fluctuation factor in switching network plan, CCITT already broken down into three busy hour type, there is:
- Busy Hour, 1-hour continuous period that part of observation time interval, which the traffic volume or total call is higher.
- Peak Busy Hour, busy hour each day or 1 hour every day where high traffic usually varies day to day, or total day.
- Time Consistent Busy Hour, 1-hour period in every day, where the traffic volume average or higher total call in time interval in several day observations.
From several calls on one time period, usually not exactly all can success until shaping conversation connection. Several conditions, such as busy line, no answer from telephone that called, and blocking in trunk group or switching central, got to cause failure to build up that connection. One calls is believed success if already the answer from customer that called. Comparison between total call that success to all call, known as CCR (Call Completion Rate). Where as total call on busy hour known as BBHCA (Busy Hour Call Attempts), the important parameter to ascertain central process capacity.
The other parameter that usually used in traffic calculations is BHCR (Busy Hour Calling Rate), which definition as total call average by one customer (telephone) as long as in busy hour.
