Digital communication system with programming information by way of the B channel

Abstract: Digital communication system, for example ISDN or ESPABX, comprising at least one exchange (1) and at least one user station (2), which exchange communicates with the user station by at least a D channel and a B channel, a service station (3) being connected to the exchange, each user station comprising a processor (21) in which, for example, the telephone number (DNR directory number) of the service station is stored, the programming information available at the service station being transmitted to the user station over the B channel.

Description: The invention relates to a digital communication system, for example ISDN or ISPABX, comprising at least one exchange and at least one telephone terminal, the exchange communicating with the telephone terminal by way of at least a D channel and a B channel. Such a system is known from the article "Digital ISDN terminal Development" by P.B. Hesdahl and S. van der Velde in PTR Philips Telecommunication and data Systems Review, September 1990, No. 3, pp. 2-10. In digital communication systems such as ISDN (Integrated Services Digital Networks) and ISPABX (Integrated Services Private Automatic Exchanges), the connected telephone terminals are customarily programmed from the exchange. In that case the user need not program the telephone terminal himself. A simple example of this relates to a telephone terminal comprising a display device on which the name of the calling person is displayed before the telephone connection itself is established. Together with the detection signals the exchange thereto sends the telephone number and the name of the calling person to the called person by way of the D channel. The speech signals are then led over the B channel. Needless to observe that also different type of programming information may be applied to the user by the exchange. For example, the exchange may define which user facilities are assigned to each user. The exchange may also remotely program various facilities such as names, numbers, etc. under function keys of the keyboard in the telephone terminal. Even remote adjustment of the baud rate, parity and the number of stop bits of a data port in the telephone terminal is feasible in this manner. A disadvantage of such a system is that such programming information is to correspond to the type of exchange used because signal transmission by way of the D channel depends on the type of exchange used. In addition, the load of the exchange is increased according as the programming information becomes more extensive. It is an object of the invention to obviate these drawbacks. For this purpose, the communication system according to the invention is characterized, in that that a service station is provided connected to the exchange, the digital communication system comprises means for transmitting programming information available in the service station to the telephone terminal over the B channel, and in that the telephone terminal is arranged for storing the programming information in its processor. Advantages of the invention are that the sending of programming information no longer depends on the type of exchange used and that the exchange no longer needs to have a large capacity. Furthermore, the speed at which the programming information is transmitted may, in essence, be increased, because the capacity of the B channel is generally larger than that of the D channel. It is observed that the document "Zwei Kanäle - doppelter Nutzen" by Peter Conrad in NET Nachrichten Elektronik und Telematik, May 1991, No. 5 pp. 203-206 discloses a system in which software is automatically downloaded from a server to a plurality of PC's via the telephone network. In this document, it is not disclosed to send programming information to a telephone terminal and to use a dedicated server for that instead of the exchange in order to reduce the load of the exchange. The invention will be further explained hereinafter with reference to the drawing Figure showing a communication system according to the invention. The communication system according to the invention comprises an exchange 1, one or a plurality of telephone terminals 2 and a service station 3. Each telephone terminal 2 is connected in known fashion to the exchange 1 by way of a D channel for detection/service signals and by way of two B channels for speech and/or data signals. The D channel customarily has a capacity of 16 Kbit/s and each B channel 64 Kbit/s. The system according to the present invention is arranged, so that the programming information for the telephone terminal 2, which information is stored in the service station 3, is transmitted to the telephone terminal 2 by the B channel. This may basically be effected in two ways. In the first embodiment of the system the (micro)processor 21 installed in the telephone terminal 2 has stored the telephone number (DNR directory number) of the service station 3. The processor 21 independently sends out a call to the service station for gaining access to the information stored therein. Once a connection between the telephone terminal and the service station has been established, the service station sends the desired programming information by the B channel along the exchange. The connection then relates to a so-called end to end protocol and does not load the capacity of the exchange. In the case where the telephone terminal relates to a telephone set comprising a processor and a picture screen, the desired programming information may be formed by a name belonging to a specific telephone number. The exchange sends by the D channel only the telephone number of the person who calls the telephone terminal. The processor searches in its memory the name belonging to that number and displays this name on the picture screen before the receiver is lifted off the hook and the connection is established. If the memory does not yet contain this name, the processor (afterwards) independently calls the service station via the exchange in order to obtain as yet the desired combination of name and telephone number via the B channel. For avoiding a new telephone terminal, whose processor knows only few name-number combinations, independently sending out a call to the service station subsequent to each call and for avoiding the exchange being overloaded at peak hours, calls from the telephone terminal may be bundled. It is also possible to program a telephone terminal in such a way that only at night, when the exchange is loaded to a minor degree, calls to the service station are made by the telephone terminal. In a second embodiment of the system not the telephone terminal places a call but the service station does. The service station then consecutively calls all the telephone terminals connected to the exchange and supplies them with the information desired by them. In this case it is essential that each processor in the telephone terminals should have stored in its memory the telephone number of the service station and can thus detect that the service station is calling. The processor then avoids a speech or data call being detected and leads the data to the processor itself by the B channel, if so required, by adapting the baud rate. In the case of above example of combinations of names and telephone numbers, a service station may thus update the telephone lists desired by the various telephone terminals. In another example an operator at the service station may remote-transmit telephone terminal setting data by way of the B channel. In this manner the setting of various telephone terminals may be performed from one central location, whereas each telephone terminal receives its own specific setting data. The operator concerned may perform the setting activities via an ISPABX system within a company but also via an ISDN system to which large groups of users are connected.

Claims: Digital communication system comprising at least one exchange and at least one telephone terminal comprising a processor (21), the exchange being arranged for communicating with the telephone terminal by way of at least a D channel and a B channel, the B channel having a larger bandwidth than the D channel, characterized in that a service station (3) is provided connected to the exchange (1), the digital communication system comprises means for transmitting programming information available in the service station to the telephone terminal over the B channel, and in that the telephone terminal is arranged for storing the programming information in its processor (21). Digital communication system as claimed in Claim 1, characterized in that the processor (21) is arranged for automatically calling the service station (3) for requesting programming information from the service station. Digital communication system as claimed in Claim 2, characterized in that the processor (21) is arranged for bundling various requests for programming information and sends them to the service station (3) by means of a single telephone call. Digital communication system as claimed in Claim 2 or 3, characterized in that the processor (21) is arranged for sending out requests for programming information at predetermined instants when the system has a small load. Digital communication system as claimed in Claim 1, characterized in that the service station (3) is arranged for calling each telephone terminal (2) for sending specific programming information to each telephone terminal via the B channel. Digital communication system as claimed in Claim 5, characterized in that each telephone terminal (2) is arranged for recognizing any call from the service station (3). Digital communication system as claimed in Claim 6, characterized in that the telephone terminal is arranged for leading the programming information to the processor (21) via the B channel without detecting any speech or data call. Digital communication system as claimed in Claim 7, characterized in that the telephone terminal is arranged for adapting the data in the B channel are led to the processor (21) by way of an adaptation of the baud rate. Digital communication system as claimed in one of the Claims 5 to 8, characterized in that the service station (3) comprises means so that a service station operator can adjust each telephone terminal (2) by adjusting data over the B channel along the exchange.

Inventors: HESDAHL PIET BERNARD, KLIK CORNELIS MACHIEL, HESDAHL, PIET BERNARD, KLIK, CORNELIS MACHIEL
Applicants: KONINKL PHILIPS ELECTRONICS NV, KONINKLIJKE PHILIPS ELECTRONICS N.V.
Application year: 1992
Main classification: H04Q11
IPC codes: H04Q11, H04M3