telecommunications Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than tha ...

, busy-hour call attempts (BHCA) is a

teletraffic engineering Teletraffic engineering, telecommunications traffic engineering, or just traffic engineering when in context, is the application of transportation traffic engineering theory to telecommunications. Teletraffic engineers use their knowledge of sta ...

measurement used to evaluate and plan capacity for

telephone network A telephone network is a telecommunications network that connects telephones, which allows telephone calls between two or more parties, as well as newer features such as fax and internet. The idea was revolutionized in the 1920s, as more and more ...

s. BHCA is the number of

telephone call A telephone call is a connection over a telephone network between the called party and the calling party. First telephone call The first telephone call was made on March 10, 1876, by Alexander Graham Bell. Bell demonstrated his ability to " ...

s attempted at the sliding 60-minute period during which occurs the maximum total

traffic load Traffic comprises pedestrians, vehicles, ridden or herded animals, trains, and other conveyances that use public ways (roads) for travel and transportation. Traffic laws govern and regulate traffic, while rules of the road include traffic ...

in a given 24-hour period (BHCA), and the higher the BHCA, the higher the stress on the network processors. BHCA is not to be confused with busy hour call completion (BHCC) which measures the throughput capacity of the network. If a bottleneck in the network exists with a capacity lower than the estimated BHCA, then congestion will occur resulting in many failed calls and customer dissatisfaction. BHCA is usually used when planning telephone switching capacities and frequently goes side by side with the Erlang unit capacity calculation. As an example, a telephone exchange with a capacity of one million BHCA is estimated to handle 250,000 subscribers. The overall calculation is more complex however, and involves accounting for available circuits, desired blocking rates, and Erlang capacity allocated to each subscriber.

Determination

The busy hour is determined by fitting a horizontal

line segment In geometry, a line segment is a part of a straight line that is bounded by two distinct end points, and contains every point on the line that is between its endpoints. The length of a line segment is given by the Euclidean distance between ...

equivalent to one hour under the traffic load curve about the peak load point. If the service

time Time is the continued sequence of existence and events that occurs in an apparently irreversible succession from the past, through the present, into the future. It is a component quantity of various measurements used to sequence events, t ...

interval is less than 60 minutes, the busy hour is the 60-minute interval that contains the service timer interval. In cases where more than one busy hour occurs in a 24-hour period, ''i.e.,'' when saturation occurs, the busy hour or hours most applicable to the particular situation are used.

Determination

References

See also