Interoffice callback arrangement
US4166929A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 17, 1978 |
| Grant date | Sep 4, 1979 |
| Priority date | — |
| Expiry date | Feb 17, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q3/54533
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A telephone switching system is disclosed with facilities for processing interoffice callback information over a common channel interoffice signaling system (4) between program controlled call processors (21, 34) in call originating and terminating offices (1, 2) upon encountering a called station busy condition. The terminating office call processor (34) is equipped to examine the busy-idle status of the called station (5) by consulting its supervisory memory (46) and by directed called station line scanning and then to enable an automatic call retry only after it is determined that the called station has become idle. Each of the call processors (21, 34) includes an originating register-callback register (47) for storing callback information comprising the calling and called station identities originating office identity, a callback code dialed from a calling station (3), a mark to specify the callback mode of register operation, a line recheck time delay and a time limit on the callback service. Automatic callback is effected in one arrangement by transferring the callback information from the originating to terminating office, ascertaining when the called station becomes idle, a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.