The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 05, 1985
Filed:
Jun. 27, 1983
Joseph M Bensadon, Germantown, MD (US);
Norman F Brickman, Potomac, MD (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A system is disclosed to provide X.21 in-band call establishment signaling in the data path of a data communication system by utilizing a data port, digital switch and telephone signaling call processor in a satellite communications controller. The system includes an X.21 signaling protocol between a DTE and the satellite communications controller on the terrestrial side and allows self-switched digital data port functions in lieu of associated voice port and line functions as practiced in the prior art. An important aspect is that the signaling rate is the same as the line data rate. The data port goes through three generalized states during a normal call process. The first general state is idle, the second general state is the signaling state and the third general state is the data transfer state. At the start of the signaling state, the E input to the call processor is activated for the appropriate port. Call establishment signals are then processed through the digital switch and an X.21 adapter to the system's control processor. In the third data transfer state, the call establishment signaling has been completed and all data bits go through the digital switch and are transmitted to the digital interface. At the end of the call the data port goes back to the first, idle state. The significant overall feature of the system is the provision for X.21 in-band signaling on the terrestrial side of the satellite communications controller so that a digital data port can accept X.21 in-band call processing type signals. The digital data port detects the call processing type signals with the X.21 protocol and passes them on to the X.21 adapter in the satellite communications controller.