In traffic engineering, the busiest 60-minute period of the day, ideally as determined by empirical traffic studies. See also traffic engineering.
The one hour of the day that a telephone system handles the most calls. Most internal PBXs and even the telco systems are not designed to handle 100% of the calls during the busy hour. The actual busy hour changes over time depending on the habits of the population. For example, the Internet has caused the busy hour to be later in the evening when people come home from work and start surfing the Web. See BHCA.