Multiplex communications – Pathfinding or routing – Combined circuit switching and packet switching
Reexamination Certificate
1997-04-21
2001-02-20
Marcelo, Melvin (Department: 2739)
Multiplex communications
Pathfinding or routing
Combined circuit switching and packet switching
C370S356000
Reexamination Certificate
active
06192045
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to computer data transmission and more particularly to the transmission of setup data over the Public Switched Telephone Network (PSTN) between geographically distant computers.
BACKGROUND OF THE INVENTION
The need to exchange data between computers has never been greater. For example, new demands on traditional Point-of-Sale applications require immediate (near real time) sales data to be transmitted from retail stores to their central office. Electronic Data Interchange (EDI)'s goal of paperless electronic commerce between customers and suppliers requires that computers be able to exchange order and payment information 24 hours a day. And multinational corporations with offices around the world need to be able to exchange files, send faxes, and conduct voice and multimedia sessions with employees at any time of day for minimal cost.
Existing methods for exchanging data (including fax and voice) between two geographically distant computers or fax machines utilize (1) dial-up point-to-point connections over the Public Switched Telephone Network (PSTN); (2) dedicated transmission connections (also known as private lines or leased lines); and (3) dial-up data network connections, like the Internet. Method 1 requires one computer to initiate a data exchange with the other by using the PSTN to establish a long distance phone call during which the two computers exchange data. This Method 1 is cost effective for weekly or monthly exchanges of small amounts of data. However, it is undesirable for lengthy data transfers, due to the toll time charges associated with long-distance phone calls.
Method 2 utilizes dedicated transmission lines between two computers for exchanging data. For frequent exchanges of large amounts of data, Method 2 is more cost effective than Method 1 but typically requires a fixed monthly payment for the dedicated transmission line, regardless of the amount of data exchanged. As with Method 1, the computers are able to exchange data at any time, although dedicated transmission lines do not incur the overhead or delay associated with Method 1.
Method 3, using dial-up data networks, like the Internet, to transfer data, improves upon Methods 1 and 2 since there are (typically) no long-distance fees associated with connecting to the Internet. Another benefit is that Internet Service Providers (ISP) provide access to the Internet at rates significantly lower than the rates for dedicated transmission lines.
For two computers to exchange data over the Internet at any time, they must be connected to the Internet 24 hours a day or connected at predetermined times, or use a person at one computer to place a telephone call to a person at the other computer to tell him/her to become connected with the Internet. Unfortunately, when the data transferred is infrequent and/or small in size, the cost of 24-hour connection to the Internet can be greater than the costs associated with a direct point-to-point connection over the PSTN between the two computers. And connecting at predetermined times precludes the transmission of real-time or near real-time data and does not provide any flexibility, for example, if heavy data traffic slows the communication.
A more cost effective method would combine the best features of Methods 1 and 3 to allow data transfers over the Internet, but not require that both computers maintain a 24-hour connection to the Internet or rely on a predetermined connection schedule. It would be ideal if there were a way that both computers would automatically, without human intervention, be able to connect to the Internet only when data exchange is required so that connect-time charges would be kept to a minimum.
SUMMARY OF THE INVENTION
The present invention seeks to minimize the costs of exchanging data over geographically separate computers and fax (facsimile) machines. It provides such cost savings by enabling two computers to use dial-up data networks (“network”), like the Internet, to exchange data and enabling them to dynamically connect to the Internet only when there is a need to transfer data by using a “callback” mechanism. At all other times, the computers are not connected to the network.
When one computer (the “originating” computer) determines the need to exchange data with another computer (the “receiving” computer) it uses a preconfigured mapping table to obtain the phone number associated with the receiving computer. The originating computer connects to the PSTN via a modem and dials the receiving computer's phone number, allowing the receiving computer to receive several ring pulses. The originating computer then terminates the unanswered phone call and proceeds to dial a phone number to establish a dial-up connection to the data network associated with the receiving computer. Once connected, it establishes a connection with the receiving computer. The receiving computer, by this time, has dialed up and been connected to the same data network. All of these steps are programmed in the two computers and are performed without human intervention.
When the receiving computer detects an incoming phone call on its modem, it extracts the Automatic calling Number Identification (ANI) information. ANI is generated by the local exchange carrier using in-band signaling to transmit information, between the ring pulses, such as the calling party's phone number and name. This is not a standard feature for phone service. A monthly fee is normally levied to allow the receiving party to obtain ANI information. Consequently, the receiving computer must arrange with its local telephone company for ANI service.
The receiving computer uses the originating computer's phone number, contained in the ANI information, to determine how to respond to the incoming, and as yet, unanswered phone call. If the receiving computer does not “recognize” the phone number as one from a list of originating computers' phone numbers, it can answer the phone call. This allows the computer to respond appropriately to normal phone call requests to establish a point-to-point dial-up connection for data transfer or to answer an incoming fax, or to allow an individual to answer a voice call.
If the receiving computer recognizes the phone number (it is on the list) it does not answer the phone call. The incoming phone call is then terminated, by the originating computer, preferably after two rings. The receiving computer records, in its memory, an identification of the originating computer and the data network associated with the obtained ANI information. It dials a phone number to its Internet Service Provider to establish a dial-up connection to the data network. The receiving computer is connected with the originating computer through the data network. If the network is the Internet one computer is connected to the other using the identification of the IP address. When the computers have finished exchanging data, they disconnect.
This novel use of ANI, using it to synchronize two computers to become simultaneously connected to the same dial-up data network, provides a clear advantage over a 24-hour connection, since connect-time charges are accrued only when data is exchanged—once data transfer has been completed the computers disconnect from the network. Similarly, the receiving computer's use of ANI to determine when to dial-out results in reduced connect-time charges (compared to not using ANI and dialing-out with each incoming phone call). Also, ANI allows the receiving computer to connect to different data networks based on the originating computer—a system that did not use ANI would not be able to distinguish between originating computers and would always call the same data network. Finally, ANI provides the capability for non-callback-type calls to be processed conventionally, i.e., allows the establishment of a normal point-to-point dial-up connection, fax reception, or voice call (for shared phone lines).
In areas that do not have ANI support, and for incoming calls that do not convey ANI informat
Libove Joel
Williams C. Wyatt
Gerber Eliot S.
Marcelo Melvin
LandOfFree
Method and system for minimizing connect-time charges... 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 system for minimizing connect-time charges..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and system for minimizing connect-time charges... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2615180