Field of the Invention
The present invention generally relates to an apparatus and method for enabling a plurality telephone services that can be utilized simultaneously on a single telephone line.
Presently, telephone companies can offer only one set of services to any and all POTS-type devices on each wire pair at the premise, because current POTS service requires one (1) line per service. This is because device types are mutually exclusive, and consequently only one device type can utilize the service line at any one time. A further limitation exists for the telephones, such that all extensions are connected to the same conversation. Presently, if multiple services are desired, an additional line is required for each additional service. This is most evident in situations such as a second loop for a fax machine or a xe2x80x9cteen linexe2x80x9d to separate parent telephone calls from those of children in a household. There are added costs for each additional line.
Also, telephone companies today cannot command any additional service revenue from the usage of extra phones, modems, and fax operations on a single line. Until now, telephone companies could not offer any extra beneficial service to the premise. Accordingly, there is a need to develop an apparatus and method to transmit a plurality of data signals in parallel with multiple analog plain old telephone services (POTS) signals, thereby providing multiple plain old telephone type services on a single telephone line.
With such an apparatus and method for enabling simultaneous multiple telephone-type services on a single telephone line, the telephone companies can offer numerous sets of services to any and/or all POTS-type devices on each wire pair at the premise.
To achieve the advantages and novel features, the present invention is generally directed to a data communications apparatus and method that allows an user to utilize, simultaneously, multiple telephone-type services to any and/or all POTS-type devices on each wire pair at the premise. The present invention provides the ability to add separately addressable POTS devices on a single service loop. This can be accomplished in a multitude of ways: first, by the use of a multipoint protocol, or second, by frequency division multiplexing (FDM), or third, by using time division multiplexing (TDM).
One embodiment of the present invention accomplishes this by using a multipoint protocol and providing each device with a unique device ID that is separately addressable.
Another embodiment of the present invention accomplishes this by using the frequency division multiplexing (FDM) method, which utilizes a device that assigns an available frequency range, within the bandwidth of the communication medium, for each device that is separately addressable.
Further, another embodiment of the present invention accomplishes this by using a time division multiplexing (TDM) method. This method utilizes a form of multiplexing in which transmission time is broken into segments, wherein each segment carries one element of one signal for each device that is separately addressable.
The modem apparatus used in this embodiment includes a memory containing a plurality of program routine sequences and a processor that performs the selected program routine sequences to enable simultaneous multiple access techniques. Suitable modems for this purpose include the modem described in commonly assigned and co-pending U.S. Patent Application entitled xe2x80x9cAPPARATUS AND METHOD FOR COMMUNICATING VOICE AND DATA BETWEEN A CUSTOMER PREMISES AND A CENTRAL OFFICExe2x80x9d, Ser. No. 08/962,796 now U.S. Pat. No. 6,061,392, filed on, Nov. 3, 1997 herein incorporated by reference, and the modem described in commonly assigned and co-pending U.S. Patent Application entitled xe2x80x9cAPPARATUS AND METHOD FOR A MULTIPOINT DSL MODEMxe2x80x9d, Ser. No. 09/031,226 filed on, Feb. 26, 1998, herein incorporated by reference.
Furthermore, the modem apparatus used in this embodiment utilizes a technique that encodes analog signals continuously utilizing variable level quadrature modulation to produce two independent analog signals for transmission over an analog communication channel such as a telephone line. This is based on a variation of the technique originally described in a commonly assigned U.S. Pat. No. 5,081,647, entitled xe2x80x9cCommunication of a Voice Signal Via Continuous Quadrature Amplitude Modulator,xe2x80x9d herein incorporated by reference.