Abstract: A communication system call transfer arrangement is disclosed which relies on the establishment of two system access buttons on every telephone served by the system. The system access buttons are operational to originate a call to any station in the system over any idle link. A call on either access line can be added to any other currently active line on the telephone set. The system access buttons at all the stations operate such that an incoming intercom call will terminate on eitherbutton, and calls can be originated from the station by using either button. For call transfer purposes the system access lines are arranged such that when the station passes a call via the access line to another station and then goes on-hook, the system access lines become idle and are available for use by the station even while the transferred call is in progress.

Abstract: There is disclosed a communication system arrangement whereby the efficiency with which pooled facilities are used can be increased by reducing the number of lines that are dedicated to the pool. This is accomplished by making available to the pool, on a priority basis, lines that have been installed for other purposes, such as, for example, conference lines and private two-way lines. The system is arranged such that dedicated pooled lines have a higher priority than other lines which are available to the pool on a decreasing priority basis. In addition, each pooled set of lines at each station is given a visual indication using the system available lamp to indicate whether an idle line remains in the pool. This arrangement allows each station user to determine, without unnecessary seizure attempts, whether or not an available line exists in the pool.