A multi-line ADSL modem (12) and network (10) whereby the multi-line ADSL modem (12) has connections to several ADSL modems (14) at a central office (CO) (16) through a master loop (18), shared loops (20, 22), and/or broadcast loops (84). The master loop (18) provides the basic connection between the multi-line ADSL modem (12) and the CO modem (14) at the central office (16) while maintaining regular telephone service. The shared loops allow the multi-line ADSL modem to share the transmission capacity with other modems. The multi-line ADSL modem is able to receive broadcast data from the central office where several loops are configured as a broadcast loop for downstream transmission only, but which can also be configured for upstream communication transmission only or in combination with downstream transmission to provide bi-directional broadband communications.

FIELD OF THE INVENTION

The present invention is generally related to communication networks, and more specifically to networks adapted to communicate over standard residential 2-wire phone lines including twisted pair loops adapted to support ADSL communications.

BACKGROUND OF THE INVENTION

Asymmetrical Digital Subscriber Lines (ADSL) is an ANSI standard identified as TI.413 issued in 1995 which presents the electrical characteristics of the ADSL signal as it should appear at a network interface. Generally, ADSL is a high-speed communication technology that allows one client modem, such as that at a remote terminal (RT), to be connected to only one central office (CO) modem through one twisted pair telephone line forming a loop. Typically, discrete multi-tone (DMT) modulation is the chosen line code technique standard in a typical ADSL system. Upstream communications, such as from RT to CO, and downstream communications, such as CO to RT, are divided from one another using frequency division multiplexing (FDM) or using echo canceling, allowing the frequency band for upstream communications to be shared with downstream communications thereby increasing the overall data rate over the loop.

Disadvantageously, the ADSL standard allows only one pair of modems (CO and RT) to communicate over the loop at the same time. The CO modem may send a downstream signal while simultaneously receiving an upstream signal from the RT, frame by frame. Similarly, the RT modem may receive the downstream communication from the CO modem and simultaneously send upstream communication signals to the CO modem.

Since the standardization of ADSL communications, there have been introduced varied implementations and customized uses of the ADSL technology, such as disclosed in commonly assigned U.S. Pat. No. 5,479,447 entitled “Method and Apparatus for Adaptive, Variable Bandwidth, High-Speed Data Transmission of a Multi-Carrier Signal over Digital Subscriber Lines, the teachings of this patent included herein by reference.

As technology evolves and the world becomes more connected including providing access to high-speed internet devices, digital TV (DTV), and even high-definition TV (HDTV), increased bandwidth will be required to connect such devices which may be located at a home or small office. Today, a single pair of twisted telephone line does not provide sufficient bandwidth to allow communications at the data rate required for some of these devices, which is about 20 Mbps for HDTV in the case of line conditioning. Although cable modems may be designed to reach up to 40 Mbps, there are many users that are required to share this data bandwidth. This means that the 40 Mbps is the burst data rate for one user, or the maximum data rate for all users.

There is desired a higher bandwidth modem and communication network that provides for a higher data rate access than that provided by conventional ADSL modems operating over a single loop of twisted pair of telephone wire. Such an improved higher data rate communication is desired to be compatible with ADSL standards, and which can support high speed communications suitable for the internet, digital TV, and even HDTV.

SUMMARY OF THE INVENTION

The present invention achieves technical advantages as an improved modem, communication network, and method of operation thereof that provides a much higher burst data rate than standard ADSL technology without increasing the number of telephone lines. A multi-line ADSL modem is provided that has connections to several ADSL modems at a central office (CO) through a master loop, as well as through shared loops and/or broadcast loops. The master loop provides the basic connection between the multi-line ADSL modem and the corresponding CO modem while maintaining regular telephone service. By accessing and using the additional shared loops, such as those serving other residential devices, the shared loop allows the multi-line modem, preferably a multi-line ADSL modem, to share the transmission capacity of the shared loop with other residential modems. Advantageously, the multi-line ADSL modem is able to receive high speed broadband broadcast data from the central office when several loops are configured as a broadcast loop such as for downstream transmission. Optionally, several loops can also be configured for broadband upstream communication if desired.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now toFIG. 1, there is illustrated generally at10a communication network having a single residential multi-line modem12serving a remote terminal13and adapted to communicate with a corresponding central office (CO) modem14serving a communications terminal15at a central office16via a master loop18comprising a conventional twisted pair telephone line. Advantageously, the multi-line modem (RT)12is also adapted to share adjacent loops20and22connected to the common central office16and serving other residential customers which may be served by a single line modem24, a multi-line modem12, or just a Plain-Old-Telephone-System (POTS) device26such as phone set or fax machine.

As shown inFIG. 1, the multi-line modem12is seen to be connected to the respective master loop18, while also being connected through a high-pass filter30to each of the shared loops20and22to separate out low frequency communications, such as voice communications, resident on the shared loops from the multi-line modem12. As shown inFIG. 1the multi-line terminal12is connected to two other shared loops20and22serving nearby residential customers which are primarily served by different respective CO modems14located at the same and common central office16. Although two additional shared loops are shown to be connected to the multi-line modem12, it is envisioned that only one shared loop, or more than two shared loops, may be connected thereto depending on the desired bandwidth to be available to a customer served by the multi-line modem12. As illustrated inFIG. 1, the bandwidth of the communication between a user of multi-line modem12is increased at least threefold to provide a significantly greater burst data rate over a single loop.

Preferably, the multi-line modem12, as well as the central office modems14are all capable of and adapted to communicate with each other in a format compatible with ADSL standards, as well as modifications thereto.

Referring now toFIG. 2, there is illustrated in more detail communication network10illustrating a frequency splitter32being provided for each standard user having both a customer premise network34and having a telephone set, voice-band modem or ISDN terminal36. Advantageously, a frequency splitter38is provided to service the multi-line modem12. Splitter38has a low pass filter40and high pass filter42servicing and connected to the master loop18, whereby the low frequency signals are separated out by the low pass filter40to the telephone set, voice-band modem, or ISDN terminal36, and the high pass filter42splitting the high frequency signals to the multi-line modem12. An additional high pass filter44is provided in splitter38to separate out the high frequency signals of each of the shared loops20and22for communication to the multi-line modem12. The high pass filters42and44provide the high frequency components of both the master loop18as well as the shared loops20and22such that they are all available via the multi-line modem12to the high data rate customer premise network shown at46.

A corresponding splitter50is provided at the central office16at the opposing end of the respective loop to separate the low frequency signals via a low pass filter52to a narrowband network54, and the high frequency signals via a high pass filter56to a broadband network58. The combination of the splitters50and the corresponding splitters32and38direct the broadband network communications over the respective loops to the customer premise networks, with the communications of the narrowband networks communications being directed to the terminals36. Advantageously, the high pass filters42and44separate out the low frequency voice band signals from the shared loop signals for minimum interference. The shared loops may be configured to serve a single line modem, or a multi-line modem, or simply a POTS device such as a phone set or fax machine. The respective high pass filters for the respective modem minimize the interference between the voice band signals and the ADSL band signals.

The multi-line modem12advantageously shares one or more other loops serving other customer terminals, without causing interference with the respective voice band signals, such that the improved customer premise network46served by the multi-line modem12achieves a significantly higher data transmission rate than that achievable with only one twisted pair of conductors forming the master loop18.

Referring now toFIG. 3, there is depicted a single-user model60of the multi-line ADSL system with the multi-line modem12connected to the master loop18, as well as to the shared loops20and22as shown inFIG. 2. The master loop is shown to be connected to a respective ATU-C modem14, and is adapted to simultaneously time share one or more of the adjacent loops20and22serving other terminals located in close proximity to modem12to achieve the significantly higher data rate, such as 40 Mbps or more. According to the present invention, the shared loops20and22may be configured, such as at the multi-line modem12, so as to provide only downstream communications from the respective CO modems14to the multi-line modem12. Optionally, the communications may be set up for bi-directional broadband communications to facilitate expanded bandwidth communications for both upstream and downstream communications.

Referring now toFIG. 4, a multi-user model of a multi-line ADSL system is shown at70. Each of the multi-line ATU-R modems12are seen to be connected to and communicate over a respective master loop18, and at the same time each of these multi-line modems12is configured to share one or more loops serving other modems24for achieving a higher data rate. The shared loops may be configured to provide to modem12downstream communications only, or providing both upstream and downstream bi-directional broadband communications. The master loop18is always set up and configured for both upstream and downstream communications.

The shared loops can be configured to share information in frames, known as time division, using different tones, known as frequency division, or using different codes known as code division. As shown, there are multiple multi-line modems12connected to share common shared loops in the multi-user mode.

Referring now toFIG. 5, a broadcast model of a multi-line ADSL system80is shown. Each multi-line ATU-R modem12is seen to be connected to a respective master loop18, and at the same time configured to time share one or more of the other adjacent loops shown at20for achieving a higher data rate than that achievable by communicating ADSL standard signals over just one loop. The shared loops20may be configured for downstream communications only, or to facilitate both upstream and downstream communications. The master loop18is typically set up for upstream and downstream communications all the time. Again, the shared loops can be shared in frames, (time division), tones (frequency division), or code division such as that similar to CDMA technology used in wireless networks. On the other hand, a broadcast service system82can integrate several shared loops into a broadcast service system and integrate several shared loops into a broadcast loop84. Each of the multi-line modems12can receive the broadcast data from the broadcast loop84with or without a master loop connected to the dedicated modems12.

In summary, the present invention achieves technical advantages as an improved multi-line modem and network, and method of using the same, whereby the improved modem communicates over both a master loop and adjacent shared loops to achieve significantly higher data rates so as to facilitate use of high data rate devices including internet communications, digital video and HDTV communication signals. No additional loops are required to be installed as a multitude of twisted pair conductor loops are already installed providing communications between the central office (CO) and the plurality of adjacent customers served by a common central office. The present invention takes advantage of the ADSL standard communications which are well suited for communication over these twisted pair loops. The multi-line modem12is specifically configured to share the adjacent shared loops and handle the bi-directional communications as a transceiver between the loops and the customer premise network. The multi-line modem12has appropriate hardware and/or software to split high data rate upstream communications from the served customer premise network to the appropriate loops providing a higher bandwidth than that provided by a single loop. Likewise, the multi-line modem12is adapted to combine the received downstream communications from each of the respective loops to form a single high data rate signal which is provided to the served customer premise network46. Again, communications over each of the loops is configures to be compatible with ADSL standards, while the communication signal provide to the customer premise network may be configures to be compatible with any number of standards including high definition television (HDTV), digital video and high speed internet access. The present invention is a low cost high bandwidth network which does not require the installation of any additional loops or the upgrade thereof while achieving a high data rate communication network.

Though the invention has been described with respect to a specific preferred embodiment, many variations and modifications will become apparent to those skilled in the art upon reading the present application. It is therefore the intention that the appended claims be interpreted as broadly as possible in view of the prior art to include all such variations and modifications.