DSL modems with analog voice band support

There is provided a DSL modem for integrating an analog voice band with DSL bands over a telephone line, where the analog voice band consists of 0-4 kHz frequency range, and the DSL bands consist of frequencies beyond 4 kHz. The DSL modem comprises a splitter configured to receive a telephone line signal from the telephone line and split the telephone line signal into an analog voice band signal and a DSL bands signal; a voice module configured to receive the analog voice band signal, digitize the analog voice band signal to generate digitized voice band signal and packetize digitized voice band signal into packetized voice band signal; a DSL module configured to receive the DSL bands signal and retrieve packetized DSL bands signal from DSL bands signal; and a multiplexer configured to multiplex packetized voice band signal and packetized DSL bands signal to generate multiplexed voice-DSL packets.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to data and voice communications. More particularly, the present invention relates to DSL modems.

2. Background Art

Over the last several years, DSL (Digital Subscriber Line) service has experienced ever-increasing demand from the subscriber community. In addition, the need to support higher-bandwidth solutions such as on-demand video services has driven the need for the DSL technology to even a higher level of demand.

By way of introduction, DSL technology is a copper loop transmission technology that converts existing copper telephone wire into a high-speed data highway with broadband speeds. xDSL is a generic name for the various versions of DSL technologies, such as ADSL (Asymmetric DSL), HDSL (High bit-rate DSL), RADSL (Rate Adaptive DSL), etc. DSL technology achieves broadband speeds over the ordinary phone wire. Although traditional analog telephone conversations, faxes and modem transmissions are limited to a 3,400 hz analog voice channel with a maximum possible modem speed of 56 kbps, DSL transmits a broader range of frequencies over existing copper telephone wire to achieve speeds over 30 times faster than a 56k modem. This significant increase in speed is possible because DSL uses a dedicated secure copper wire circuit that does not go through analog telephone switching equipment and because digital data (not an analog signal) is being transmitted.

Traditional phone service, namely “Plain Old Telephone Service” or “POTS” connects a home or small business to a telephone company office over copper wires that are wound around each other and called twisted pair. Regular voice signals travel over phone lines at frequencies ranging from 0 kHz to 4 kHz. Standard modems or analog modems use the same range of frequencies as voice, and communicate data in analog form over phone lines.

In contrast, DSL uses frequencies between 25 kHz and 1 MHz. DSL is a technology that assumes digital data does not require change into analog form and back. Digital data is transmitted to a host computer directly as digital data and this allows the phone company to use a much wider bandwidth for transmitting data to the host computer. Meanwhile, the telephone signal can be separated into voice band frequencies of 0-4 kHz and DSL bands frequencies of higher than 4 kHz using a filter that is typically referred to as a splitter, so that the voice band may still be used to transmit an analog signal concurrently with using DSL bands.

FIG. 1illustrates conventional DSL system100for installation at homes or offices. As shown, DSL system100includes splitter105that receives telephone line signal102. Splitter105is a filter that splits telephone line signal102into voice band signal107that carries frequencies of 0-4 kHz and DSL bands signal109that carries DSL bands frequencies of higher than 4 kHz. As further shown inFIG. 1, voice band signal107is communicated between splitter105and telephone115, and DSL bands signal109is communicated between splitter105and DSL modem110.

A great drawback of conventional DSL system100is that it fails to integrate analog voice and DSL communications, so that it can support analog voice and DSL communications in a single device. Rather, conventional DSL system100requires the user to use telephone115in addition to computer120for answering incoming calls via voice band107.

A solution that present systems offer for having a fully integrated telephone usage from computer120is to include a VoIP (Voice over Internet Protocol) phone system in computer120. In other words, in addition to data, voice communication is also supported through DSL bands109. However, such solution requires expensive infrastructures, such as routers, cabling, VoIP phone equipment, VoIP-enabled APBX, etc., which are not economical for home and small office applications that already have conventional telephone equipment that utilize regular phone lines.

Accordingly, there is a need to overcome the drawbacks and deficiencies in the art by providing methods and systems that can offer more affordable and less complicated alternatives to conventional solutions for integrating analog voice communications and DSL modems.

SUMMARY OF THE INVENTION

There are provided systems and methods for providing DSL modems with analog voice band support, substantially as shown in and/or described in connection with at least one of the figures, as set forth more completely in the claims.

DETAILED DESCRIPTION OF THE INVENTION

Although the invention is described with respect to specific embodiments, the principles of the invention, as defined by the claims appended herein, can obviously be applied beyond the specifically described embodiments of the invention described herein. Moreover, in the description of the present invention, certain details have been left out in order to not obscure the inventive aspects of the invention. The details left out are within the knowledge of a person of ordinary skill in the art.

The drawings in the present application and their accompanying detailed description are directed to merely example embodiments of the invention. To maintain brevity, other embodiments of the invention which use the principles of the present invention are not specifically described in the present application and are not specifically illustrated by the present drawings. It should be borne in mind that, unless noted otherwise, like or corresponding elements among the figures may be indicated by like or corresponding reference numerals.

FIG. 2is a block diagram illustrating DSL system200, according to one embodiment of the present invention. In the embodiment ofFIG. 2, splitter205is a filter located outside of DSL modem210for splitting telephone line signal202into voice band signal207that carries frequencies of 0-4 kHz and DSL bands signal209that carries DSL bands frequencies of higher than 4 kHz. As further shown inFIG. 2, voice band signal207is communicated between splitter205and telephone215, and DSL bands signal209is communicated between splitter205and DSL modem210. Also, voice band signal207is communicated between splitter205and voice module230of DSL modem210. In operation, splitter205receives telephone line signal202over the twisted pair of copper wires (not shown) from the Central Office (CO) via RJ-11 connection203or phone line jack. After splitting telephone line signal202into voice band signal207and DSL bands signal209, voice band signal207is communicated to telephone215via RJ-11 connection206and DSL bands signal209is communicated to DSL modem210via RJ-11 connection204and RJ-11 connection241. In contrast to conventional DSL systems, voice band signal207is also communicated to DSL modem210via RJ-11 connection204and RJ-11 connection208.

As shown inFIG. 2, DSL modem210includes voice module230, DSL module240and multiplexer/demultiplexer250. DSL module240operates similar to conventional DSL modem110for processing DSL bands signal209to retrieve the data embedded in DSL bands signal209, e.g. data packetized according to Internet Protocol (IP) format, and to send the IP DSL data packets to multiplexer/demultiplexer250. Voice module230also receives voice band signal207and digitizes voice band signal207using a codec or analog-to-digital converter (not shown) to generate digital samples of voice band signal207. Voice module230then packetizes digital samples of voice band signal207using the IP format and transmits IP voice packets to multiplexer/demultiplexer250. Multiplexer/demultiplexer250multiplexes IP DSL data packets and IP voice packets and sends multiplexed IP voice-DSL packets to host or computer220over communication line212via RJ-45 connection213or computer line jack. Computer220includes application software or hardware modules (not shown) that can demultiplex IP voice-DSL packets to separate IP voice packets and IP DSL data packets. Computer220is also capable of processing the IP voice packets to extract caller identification information from the IP voice packets, as known in the art, and further convert the IP voice packets to an analog voice signal using a codec or digital-to-analog converter (not shown) for playing by a speaker. According to this embodiment, computer220may alert the user about the incoming call and/or display the caller identification number of the incoming call and determine whether the user would like to answer or reject the incoming call. For example, computer220may include a look-up table including caller identification numbers, names, photos, etc., such that when the caller identification number is extracted from the voice signal, it can be displayed on the screen in a pop-up window. Further, if the user is unavailable or rejects the incoming call, computer220may function as an answering machine and record a message. Generally, computer220may also function as a recording device and record voice communications in the voice band. The incoming call may be answered by telephone215, or voice module230may include additional data access arrangement (DAA) circuitry for answering the incoming call by taking the telephone line off-hook.

If the incoming call is answered, computer220also receives user's analog voice signal via a computer microphone and digitizes user's analog voice signal using a codec or analog-to-digital converter (not shown) to generate digital samples of user's analog voice signal. Computer220then packetizes digital samples of user's analog voice signal using the IP format and multiplexes IP voice packets with user's IP DSL data packets and sends multiplexed IP voice-DSL packets to DSL modem210over communication line212via RJ-45 connection213. Multiplexer/demultiplexer250of DSL modem210receives the multiplexed IP voice-DSL packets over communication line212and demultiplexes IP voice-DSL packets to separate IP voice packets and IP DSL data packets. Multiplexer/demultiplexer250then routs IP voice packets to voice modules230and routs IP DSL data packets to DSL module240for further processing. Next, voice module230depacketizes IP voice packets to obtain digitized voice samples and converts the digitized voice samples to an analog voice signal using a codec or digital-to-analog converter (not shown) for transmission over telephone line signal202through voice band signal207via RJ-11 connection208and RJ-11 connection206. Also, DSL module240processes data within the IP DSL data packets similar to conventional DSL modem110and transmits the DSL data over telephone line signal202through DSL bands signal209via RJ-11 connection241and RJ-11 connection204.

Turning toFIG. 3, a block diagram of DSL system300is illustrated, according to another embodiment of the present invention. In the embodiment ofFIG. 3, splitter305is a filter located inside of DSL modem310for splitting telephone line signal302into voice band signal307that carries frequencies of 0-4 kHz and DSL bands signal309that carries DSL bands frequencies of higher than 4 kHz. As further shown inFIG. 3, voice band signal307is communicated between splitter305and telephone315, and DSL bands signal309is communicated between splitter305and DSL module340. Also, voice band signal307is communicated between splitter305and voice module330.

The operation of DSL modem310is now described in conjunction withFIG. 4, which illustrates communication method400for communicating information by DSL modem310to computer320, according to one embodiment of the present invention. At step405, DSL modem310receives telephone line signal302over the twisted pair of copper wires (not shown) from the CO via RJ-11 connection303. At step410, splitter305receives telephone line signal302and splits telephone line signal302into voice band signal307and DSL bands signal309, where voice band signal307is communicated to telephone315via RJ-11 connection308and to voice module330. Next, at step415, DSL module340operates similar to conventional DSL modem110and processes DSL bands signal309to retrieve the data embedded in DSL bands signal309, e.g. data packetized according to Internet Protocol (IP) format, and to send the IP DSL data packets to multiplexer/demultiplexer350.

At step420, voice module330receives voice band signal307and digitizes voice band signal307using a codec or analog-to-digital converter (not shown) to generate digital samples of voice band signal307. Voice module330then packetizes digital samples of voice band signal307using the IP format and transmits IP voice packets to multiplexer/demultiplexer350. At this point, in step425, multiplexer/demultiplexer350multiplexes IP DSL data packets and IP voice packets. Next, at step430, multiplexer/demultiplexer350sends multiplexed IP voice-DSL packets to host or computer320over communication line312via RJ-45 connection313. At step435, computer320demultiplexes IP voice-DSL packets to separate IP voice packets and IP DSL data packets. In one embodiment, computer220processes the IP voice packets and extracts caller identification information from the IP voice packets, as known in the art. Further, at step440, computer320converts the IP voice packets to an analog voice signal using a codec or digital-to-analog converter (not shown) for playing by a speaker. For example, computer320may alert the user about the incoming call and/or display the caller identification number of the incoming call to determine whether the user would like to answer or reject the incoming call. Also, computer320may include a look-up table including caller identification numbers, names, photos, etc., such that when the caller identification is extracted from the voice signal, it can be displayed on the screen in a pop-up window. Further, if the user is unavailable or rejects the incoming call, computer320may function as an answering machine and record a message. Generally, computer320may also function as a recording device and record voice communications in the voice band. The incoming call may be answered by telephone315, or voice module330may include additional data access arrangement (DAA) circuitry for answering the incoming call by taking the telephone line off-hook.

Now, turning toFIG. 5, it illustrates communication method500for communicating information from computer320to DSL modem310, and processing by DSL modem310, according to one embodiment of the present invention. If computer320answers the incoming call, at step505, computer320receives user's analog voice signal via a computer microphone and, at step510, computer320digitizes user's analog voice signal using a codec or analog-to-digital converter (not shown) to generate digital samples of user's analog voice signal. Next, at step515, computer320packetizes digital samples of user's analog voice signal using the IP format. At step520, computer320multiplexes IP voice packets with user's IP DSL data packets and sends multiplexed IP voice-DSL packets to DSL modem310over communication line312via RJ-45 connection313. At step525, multiplexer/demultiplexer350of DSL modem310receives the multiplexed IP voice-DSL packets over communication line312and, at step530, demultiplexes IP voice-DSL packets to separate IP voice packets and IP DSL data packets and routs IP voice packets to voice modules330and IP DSL data packets to DSL module340for further processing. At step535, voice module330depacketizes IP voice packets to obtain digitized voice samples and converts the digitized voice samples to an analog voice signal using a codec or digital-to-analog converter (not shown) for transmission over telephone line signal302through voice band signal307via RJ-11 connection303, at step540. Also, at step545, DSL module340processes data within the IP DSL data packets similar to conventional DSL modem110and, at step550, transmits the DSL data over telephone line signal302through DSL bands signal309via RJ-11 connection303.

Thus, various embodiments of the present invention, as described above, can integrate analog voice communications and DSL modems, and offer many advantages and applications. For example, in a small office environment, an insurance agent may receive analog voice calls via its broadband DSL modem and obtain caller identification information to access internal or online database based on caller identification information to provide faster quotes and improve customer service. Similarly, stock broker terminals may receive analog voice calls via their broadband DSL modems and obtain caller identification information to access customer records based on caller identification information for stock transactions. Also, an application for the integrated analog voice line and DSL modems may be found in the medical industry, where a nurse help line may receive analog voice calls via a broadband DSL modem and obtain caller identification information to access patient's records based on caller identification information to provide medical assistance.