Multiplex communications – Pathfinding or routing – Combined circuit switching and packet switching
Reexamination Certificate
1999-10-08
2003-09-16
Cangialosi, Salvatore (Department: 2661)
Multiplex communications
Pathfinding or routing
Combined circuit switching and packet switching
C370S466000
Reexamination Certificate
active
06621814
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to a method for transmitting voice data in data packets upon utilization of additional supplymentary service, wherein a terminal unit working in packet-based fashion transmits and receives voice data in data packets.
2. Description of the Prior Art
A data packet usually contains a plurality of data words with a predetermined plurality of bit places; for example, what are referred to as octettes having eight bit places. In general, octettes that belong to the data header can be distinguished in a data packet. For example, the destination of the data packet is indicated in the data of the data header. On the other hand, for example, data is also contained in the data header that determine the type of data packet. In addition to the data header, there are usually octettes that contain the payload information; for example, the voice data. Data words also are transmitted that form an end section of the data packet and contain, for example, a checksum for error recognition and error correction.
Standards for methods of transmitting voice data in data packets are prescribed, among other things, in the following ITU-T Recommendations (International Telecommunication Union-Telecommunication):
H.323, “Packet based multimedia communications systems”, 02/98;
H.450.1, “Generic functional protocol for the support of supplementary services in H.323”, Jan. 27, 1998;
H.450.2, “Call transfer supplementary service for H.323”, Jan. 27, 1998; and
H.450.3, “Call diversion supplementary service for H.323”, Jan. 27, 1998.
The basic concept for transmitting multimedia data in data packets is standardized in the Standard H.323. This basic concept, in particular, also applies to the transmission of voice data.
The Standard H.450.1 contains general definitions for the methods and signaling protocols for realizing additional supplymentary service in the connection between what are referred to as H.323 devices; i.e., devices that work according to the Standard H.323. The Standard H.405.1 thus forms the basis for the Standards H.450.2 and H.450.3 that are directed to individual supplymentary service.
The Standard H.450.2 contains definitions for the supplymentary service of “call transfer.” Given the supplementary service “call transfer ,” a calling A-subscriber first sets up a connection to a called B-subscriber. When the connection has been set up, the A-subscriber then calls a third C-subscriber and subsequently hangs up. After the A-subscriber has hung up, there is a connection between the B-subscriber and the C-subscriber.
The Standard H.450.3 contains definitions for the supplementary service “call division.” This supplementary service makes it possible for the call to be rerouted to some other terminal equipment before the setup of a connection.
According to the Standards H.450.2 and H.450.3, supplementary service usually are made available in the terminal equipment themselves. The terminal equipment is therefore constructed in a complex way and has an extensive program system. A central instance for the supplementary service usually is not required.
Traditional voice terminal equipment transmits the voice data in data channels. In the simplest case, a voice channel is formed by a line that is used only for a single connection. Analog or digital voice data is exchanged via the line without interruption by information for connection control. Usually, however, the voice data belonging to different connections is transmitted on a line in the time-division multiplex method. A time section for the transmission of the voice data is defined for each connection within time frames that follow one another in time.
Given traditional ISDN terminal equipment (Integrated Services Digital Network) and, in particular, given system telephones at private branch exchanges (PBS), there are a multitude of other, additional supplementary service; for example:
call waiting;
charge display;
three-party conference;
hold for inquiry;
negotiating;
blocking outgoing calls;
connection without dialing, what is referred to as baby call; and
call back when busy.
It is to be anticipated that standards will be prescribed little by little by the ITU for these additional supplementary service-these containing definitions for using the supplementary service given a transmission of voice data in data packets. However, several years will pass before such standards are defined. After the publication of binding standards, these must be converted into programs for the drive of H.323 terminal equipment so that another development time will have to be provided. Only after this can the user of H.323 terminal equipment employ all additional supplementary service that are already standard for the voice transmission in a voice channel given ISDN terminal equipment and system telephones. There is also a similar situation given other methods for the transmission of voice data in data packets.
An object of the present invention, therefore, is to specify simple methods for transmitting voice data in data packets with additional performance features wherein additional supplementary service can be used without great standardization, development or, respectively, programming outlay for terminal units. Further, electronic units and programs should be specified that serve for the implementation of the methods.
SUMMARY OF THE INVENTION
Accordingly, the present invention considers the fact that additional supplementary service have been present for a long time in switching equipment for circuit switching of voice connections in a circuit-switched telecommunication network; for example, in a network wherein voice data is transmitted in voice channels, such as in telecommunication systems of Siemens AG. Since the supplementary service are centrally performed in the switching equipment, the terminal equipment to be connected to the switching equipment is constructed comparatively simply. For example, the desire to use a supplementary service is signaled to the switching equipment from a telephone. In response thereto, the supplementary service of the switching equipment is activated. The switching equipment likewise sends signals to the telephone given employment of the supplementary service with which, for example, signal tones are generated or numerical sequences are sent to the telephone.
The present invention is also based on the perception that it is possible, with respect to the additional supplementary service, to forego the realization of the supplementary service in the terminal equipment for the transmission of voice data in data packets as in the case of terminal equipment for the transmission of voice data in the voice channel to be directly connected to the switching equipment; i.e., without an interface unit for the conversion of transmission signals. Terminal equipment that works in packet-based fashion thus also can be simply constructed because only measures for signaling between terminal equipment and exchange equipment have to be implemented in the terminal equipment. By contrast, no measures that relate to the actual supplementary service need be implemented in the terminal equipment.
In the inventive method, the terminal unit working in packet-based fashion is connected to the switching equipment with the assistance of an interface unit. The interface unit converts transmission signals coming from the switching equipment into transmission signals for the terminal unit, and converts transmission signals coming from the terminal unit into transmission signals for the switching equipment. During use of the additional supplementary service in the switching equipment for controlling the terminal equipment working in packet-based fashion, method steps are implemented in the inventive method that are to be implemented in the use of the additional supplementary service in the switching equipment for controlling terminal equipment connectable to the switching equipment without an interface unit for protocol conversion for the transmission of voice data in a voic
Coen Guy
Korpi Markku
Mueller Harald
Bell Boyd & Lloyd LLC
Cangialosi Salvatore
Siemens Aktiengesellschaft
LandOfFree
Method and apparatus for transmitting voice data in data... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for transmitting voice data in data..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for transmitting voice data in data... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3085376