WO2001028149A1

WO2001028149A1 - System and method for enabling simultaneous multi-channel digital communications with multiple customer premises devices over a shared communication link

Info

Publication number: WO2001028149A1
Application number: PCT/US2000/028330
Authority: WO
Inventors: Alan Albert Jones; Benjamin Elie Isaac; Kenneth Henry Oehrig; David Warren Loar; Forrest James Brown; Todd Bedros Smith
Original assignee: Sharegate Inc.
Priority date: 1999-10-14
Filing date: 2000-10-13
Publication date: 2001-04-19
Also published as: WO2001028164A1; AU1087501A; AU7879300A

Abstract

A communication system includes a host device (20) and a plurality of peripheral node interface circuits (PNIs) (22) coupled to the shared communicatin link (16). The host device transmits and receives digital information over the link (16) using a plurality of first communication channels. Each PNI is associated with a particular first communication channel and receives or transmits digital information from or to the host device over the first channel. A device (18) may be coupled to each PNI for receiving or transmitting analog information from or to the PNI.

Description

SYSTEM AND METHOD FOR ENABLING SIMULTANEOUS MULTICHANNEL DIGITAL COMMUNICATIONS WITH MULTIPLE CUSTOMER PREMISES DEVICES OVER A SHARED COMMUNICATION LINK by

Forrest J. Brown, Benjamin E. Isaac, Alan A. Jones, David W. Loar, Kenneth H. Oehrig, Edward S. Samuels, and Todd B. Smith

Cross-Reference to Related Applications

Embodiments of the present invention claim priority from U.S. Provisional Patent Application Serial No. 60/159,378, filed October 14, 1999, and are related to a U.S. utility patent application entitled "System and Method for Enabling

Simultaneous Multi-Channel Analog Communications with Multiple Customer Premises Devices Over a Shared Communication Link," attorney docket No. 080632/0111, filed October 13, 2000, a U.S. provisional patent application entitled "Synthetic Delay Line for Mitigating the Effects of Quarter-Wave Shorts Caused by Branched Wiring on Communications Over a Shared Communication

Link," attorney docket no. 080632/0117, filed October 13, 2000, and U.S. Utility Patent Application Serial No. 09/137,074, filed August 20, 1998, which is a continuation-in-part of U.S. Patent No. 5,737,400. The contents of each of these applications are incorporated by reference herein.

Background of the Invention

1. Field of the Invention

The present invention relates, generally, to a customer premises communication system and, in preferred embodiments, to such systems and processes for enabling simultaneous multi-channel digital communications with multiple customer premises devices over a shared communication link.

2. Description of Related Art

In conventional household telephone systems, a two-wire twisted pair telephone line is used to bring a single analog audio communication channel into the home to provide Plain Old Telephone Service (POTS). Additional channels may be added by connecting additional twisted pair telephone lines into the home. Within the home, each channel may be connected to multiple telephone extensions by connecting multiple telephones to the twisted pair telephone line corresponding to that channel.

Subsequent innovations enable special telephone jacks to be coupled to household AC power wiring for providing telephone capability where no conventional telephone jacks exist. Communication between a main communication module and the special telephone jacks occurs through signaling over the AC power wiring. However, such systems do not add multiple independent telephones, but merely add extensions to an existing single telephone channel. In households where POTS satisfies the communication needs of its residents, the above-described methods of providing telephone service are usually sufficient.

At the other extreme, businesses having a need for large numbers of independent telephone lines cannot practically or efficiently run additional twisted pair telephone into their premises for each desired channel. In many organizations using more than just a few telephone lines, calls are delivered by specialized switching equipment, often located on the organization's premises. Calls are carried to the switching equipment from the telephone company via special high capacity circuits such as Tl lines. These circuits are time division multiplexed (TDM) to support 24 individual telephone signals, with each signal occupying a specific time slot in each TDM frame. The Tl line is connected to the on-premises switching equipment such as a private branch exchange (PBX) , which reconstructs the individual telephone signals and makes them available to standard telephone devices.

A PBX could connect the 24 reconstructed telephone signals directly to 24 individual telephones, but this would be an inefficient use of the corresponding telephone lines because the telephone circuits are idle most of the time. To maximize the usefulness of Tl delivery, on-premises switching equipment typically connects the telephone devices to a circuit only when a call is present. To do this, the switching equipment is provided with a method for determining which telephone is to be connected to a particular call. For incoming calls, for example, a caller might be prompted to enter an extension. For outgoing calls, the caller might have to enter a selected digit (e.g. , "8" or "9") to request an available circuit (i.e., a line for placing an outgoing call, referred to as an "outside line"). While such call connection activity is basic, it requires a significant amount of logic devices. Accordingly, many telephone switches are implemented using relatively large and powerful computers or processing devices.

For some organizations, customer contact via telephone is the primary business activity. For example, a customer support unit might have dozens of technicians available to answer calls, or a catalog sales company might have a hundred order entry clerks answering the telephone. In such organizations, the switching equipment makes more sophisticated routing decisions than simply ascertaining an extension, as described above. These kinds of telephone switches are called automatic call distributors or ACDs, and the organizations using them are known as call centers. The primary task of the ACD is to minimize the time between the arrival of an incoming call, and the call being answered by an agent. In addition, an ACD can route calls to different groups of agents, depending on the incoming line, the time of day, or other conditions. An ACD might also prompt the caller for information and then use this information to further refine the ACD routing decision. Moreover, in a call center environment, the number of idle lines (i.e. , trunks) is intended to be minimized. Most call centers consequently have a high ratio of trunks to agents.

The systems described above represent the extremes of telephone service. Homes may be satisfactorily provided with telephone service through one or two telephone lines, while large businesses may use Tl lines and PBX equipment to meet their telephone service needs. However, these extremes may not be sufficient for modern households or small offices and home offices (SOHOs), where multiple computers, independent telephones, facsimile machines, and the like may be present within the premises. With the advent of digital subscriber line (DSL) technology, it is now possible to receive multiple channels of digital information over a single twisted pair telephone line. Thus, the ability to receive multiple independent telephone channels over a single two-wire twisted pair telephone line is now a reality. However, conventional systems for distributing multiple independent telephone lines within the home or office require the use of dedicated telephone wiring that must be installed on the premises. For example, conventional systems employ a main communication module, which includes multiple RJ-11 telephone jacks. Each independent telephone line must plug directly into one of the RJ-11 telephone jacks.

More recently, attempts have been made to operate multiple independent telephones over non-dedicated standard two-wire household telephone wiring by transmitting digitized voice data in accordance with the Home Phone Network Alliance (HomePNA) data transmission standard. The digital data is then reconverted to analog voice signals at the receive (telephone) end. Such products are analogous to recently developed voice-over Internet Protocol (voIP) telephony products that are capable of converting a telephone call to digital data using a special telephone, and transmitting the data over a standard non-dedicated lOBase-T twistedpair network connection. However, such systems consume bandwidth and thus interfere with the simultaneous communication of other digital data, such as computer-to-computer communications . A need therefore exists for a call processing device which can simultaneously receive DSL communications, POTS, and other information, and distribute this information to and from devices within the customer premises over a single twisted pair telephone line without interference, and without interfering with HomePNA or other communications that may also be present on the single twisted pair telephone line.

A need also exists for a call processing device for use at customer premises which distributes communications (e.g. , telephone calls, data transfers, appliance or other device commands and status signaling) to and from different types of customer premises equipment (CPE) and controllable devices via different media such as power lines, other network wiring, or wireless systems, using various types of communication protocols.

Summary of the Disclosure

Therefore, it is an advantage of embodiments of the present invention to provide a system and method for simultaneously receiving DSL communications, POTS, and other information, and distributing this information to and from devices within the customer premises over a single twisted pair telephone line without interference, and without interfering with HomePNA or other communications that may also be present on the single twisted pair telephone line.

It is a further advantage of embodiments of the present invention to implement the aforementioned system and method in a manner that utilizes existing twisted pair household telephone wiring and thereby minimizes the need for rewiring customer premises.

It is a further advantage of embodiments of the present invention to implement the aforementioned system and method utilizing digital communications to increase noise immunity. It is a further advantage of embodiments of the present invention to implement the aforementioned system and method in devices that are capable of changing communication frequencies (channels) .

It is a further advantage of embodiments of the present invention to implement the aforementioned system and method in devices that need not be placed outside, thereby reducing physical robustness and durability requirements, and need not be installed by professional installers, thereby minimizing the number of truck rolls and installation and maintenance costs.

It is a further advantage of embodiments of the present invention to provide a system and method for distributing communications (e.g., telephone calls, data transfers, appliance or other device commands and status signaling) to and from different types of CPE and controllable devices via different media such as power lines, fiber optic links, coaxial cable, wireless links, and other network wiring, using various types of communication protocols.

These and other advantages are accomplished according to a system for communicating with multiple devices over a shared communication link within a premises. The system includes a host device and a plurality of peripheral node interface circuits (PNIs) couplable to the shared communication link. The host device transmits and receives digital information over the shared communication link using a plurality of first communication channels. Each PNI is associated with a particular first communication channel and receives digital information from the host device over that first communication channel, and transmits digital information to the host device over that first communication channel. A device may be coupled to each PNI for receiving analog information from the PNI, and for transmitting analog information to the PNI.

These and other objects, features, and advantages of embodiments of the invention will be apparent to those skilled in the art from the following detailed description of embodiments of the invention, when read with the drawings and appended claims.

Brief Description of the Drawings

FIG. 1 illustrates a simplified block diagram of a customer premises communication system according to an embodiment of the present invention. FIG. 2 illustrates the frequency spectra of the communication platforms that may be present on the internal communication link according to a preferred embodiment of the present invention.

FIG. 3 illustrates a block diagram of a customer premises communication system for communicating signals over an internal communication link according to an embodiment of the present invention.

FIG. 4 illustrates a block diagram of an example interface circuit within the host device according to an embodiment of the present invention.

FIG. 5 illustrates a spreadsheet of the frequency plan according to preferred embodiments of the present invention. FIG. 6 illustrates a block diagram of an example transmitter and receiver within a PNI according to an embodiment of the present invention.

FIG. 6a illustrates the communication of packets of data across the data communication channels and a virtual control channel superimposed over the data communication channels according to an embodiment of the present invention. FIG. 7 illustrates the frequency spectra of the communication platforms that may be present on the internal communication link, and the suck-out that results from ties-ins having a length of about 100-200 feet, according to a preferred embodiment of the present invention.

FIG. 8 is a circuit diagram of a delay line added to the distal end of each internal communication link tie-in that is connected to a PNI according to an embodiment of the present invention. FIG. 9 illustrates a block diagram of a customer premises communication system for communicating signals over AC power wiring according to an embodiment of the present invention.

Detailed Description of Preferred Embodiments In the following description of preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the preferred embodiments of the present invention.

FIG. 1 illustrates a customer premises communication system according to an embodiment of the present invention. In FIG. 1, a telephone company central office (telco CO) 14 is connected to a customer premises 10 via an external communication link 12. In preferred embodiments, the external communication link 12 comprises a twisted pair (TP) telephone line. However, in alternative embodiments the external communication link 12 can comprise other types of communication media (e.g. , Tl line, coaxial cable, fiber optic cable, satellite feeds from communications satellites, and the like), and can support protocols and services such as a digital subscriber line (i.e. , xDSL), Internet Protocol (IP) transmissions, POTS, and the like. The customer premises 10 can be, for example, a residence, home office, or business (e.g., a small business) that is provided with one or more internal communication links 16 such as a TP telephone line, an AC power line, a fiber optic link, coaxial cable, a wireless link, and the like. In accordance with the present invention, a number of devices 18 (e.g. telephones, personal computers (PCs), facsimile machines, appliances, and the like) can share one of the internal communication links 16 by coupling to the internal communication link 16 through a corresponding peripheral node interface (PNI) 22. In alternative embodiments, the PNI 22 may be incorporated as part of the device 18. The PNIs 22 may be specifically configured to accept a particular type of device 18, or may be adaptable to accept different types of devices 18. For example, a PNI 22 configured to accept a telephone may provide AC power, battery power, ringing, voice amplification, and the like, such that the telephone will appear to be a normal POTS telephone to the user. Any telephone jack in the premises can be connected to a PNI, and one telephone can be connected to each PNI. Each telephone connected to a PNI may have its own telephone number and operate essentially as an independent phone line. It should be understood that although the descriptions given herein may primarily refer to the devices 18 as telephones and the internal communication link 16 as a TP telephone line for purposes of illustration only, it should be understood that other devices and other types of internal communication links may also be employed without departing from the scope of the present invention. Generally speaking, embodiments of the present invention cover the transmission of digital data over the external communication link to multiple PNIs connected to a common internal communication link. Instead of communicating narrowband FM analog signals, embodiments of the present invention communicate wideband FM frequency shift key (FSK) modulated digital signals. The transmission of digital data has several advantages over the transmission of analog data. Analog data requires periodic amplification and is subject to noise and other interference prevalent in exterior and premises telephone wiring. By communicating information digitally over as much of the communication path as possible, many of the potential noise sources can be eliminated. In FIG. 1, a host device 20 is coupled to the external communication link 12 and the internal communication link 16, and enables communications to be transferred between the external communication link 12 and the internal communication link 16. For example, the external communication link 12 may carry POTS and DSL transmissions for communicating regular audio telephone signals and high speed internet access, respectively. The host device 20 and the PNIs 22 operate in accordance with the present invention to allow multiple telephones, facsimile machines, modems, computers, and the like to communicate independently with respect to each other over a single twisted pair (TP) telephone line 16. With the advent of ADSL and other emerging standards for DSL and IP communication, the present invention is advantageous in fulfilling the need for businesses (e.g. , call centers), and homes (e.g., personal telephone use and home office use) to use the existing telephone wiring for multiple device communication. The host device 20 and the PNIs 22 of the present invention are also advantageous because they are simple, reliable, scalable, and inexpensive. Although in preferred embodiments the host device 20 resides within the premises, in alternative embodiments the host device 20 may reside outside the premises. Within the host device 20 is an interface circuit 152. The interface circuit

152 communicates with the PNIs 22 through a bi-directional link. In embodiments of the present invention, digital signals transmitted by the PNIs 22 and received by the interface circuit 152 are decoded, converted to DSL protocols, and then applied as DSL signals to the external communication link 12. FIG. 2 illustrates the frequency spectra of communication platforms that may be present on the internal communication link 16 according to a preferred embodiment of the present invention. First, some existing communication standards will be described. As indicated in FIG. 2, POTS communication occurs from about 0 to 4 kHz, while ADSL communication occurs in a frequency band from about 25 kHz to 1 MHz. HomePNA II communication, which can be viewed as a half-duplex

Ethernet, occurs in a frequency band from about 4.5 MHz to about 9.5 MHz. The HomePNA frequency band may be used to enable computers to communicate with each other over the twisted pair telephone lines. However, unlike full duplex communications where computers can simultaneously transmit and receive, with HomePNA a computer can transmit and receive communications, but cannot transmit and receive simultaneously.

In preferred embodiments of the present invention, communication between the host device 20 and the PNIs 22 preferably occurs in a frequency range that does not interfere with the frequency spectra allocated to known communication platforms such as POTS, ADSL, and HomePNA. FIG. 2 illustrates that the ADSL frequency spectrum ends at about 1 MHz, and that the frequency spectrum for HomePNA II starts at about 4.5 MHz, leaving a frequency range from about 1 to 4 MHz in which to implement communications between the host device 20 and the PNIs 22. In preferred embodiments, 2.95 MHz was chosen as an approximate midpoint in the available frequency range, and two frequency bands on either side of that 2.95 MHz midpoint were chosen to transmit and receive signals. Thus, in preferred embodiments, a frequency band between about 2 to 2.6 MHz was chosen for transmitting signals from the PNIs 22 to the interface circuit 152. Similarly, a frequency band between about 3.3 to 3.9 MHz was chosen for transmitting signals from the interface circuit 152 to the PNIs 22.

Preferred embodiments of the present invention enable communications between the host device 20 and four PNIs 22, and thus there are actually four discrete channels of communication that occur within each of these frequency bands, corresponding to the four PNIs 22. Each frequency channel occupies a different frequency range. In other words, within the frequency range of about 2 to 2.6 MHz, there are four distinct frequency channels for PNI transmissions to the host device, and within the frequency range of about 3.3 to 3.9 MHz, there are four distinct frequency channels for host device transmissions to the PNIs. However, in alternative embodiments which enable simultaneous communications with a different number of PNIs, a different number of discrete channels of communication may exist within each frequency band. As noted above, FIG. 2 illustrates an exemplary preferred embodiment of the present invention, including the frequency bands chosen for communications between the host device 20 and four PNIs 22. It should be understood, however, that although in preferred embodiments communications between the host device 20 and the PNIs 22 occur between about 1 MHz to 4 MHz, in alternative embodiments the 4 MHz upper limit may be increased to overlap somewhat with HomePNA. The overlap is possible because embodiments of the present invention employ FM receivers that rely on a 20 dB capture point, and thus low energy amplitude modulated signals from HomePNA will not affect the FM receivers. In addition, in alternative embodiments the frequency bands may be changed to different frequencies. For example, although FIG. 2 illustrates that in preferred embodiments of the present invention a guard band 154 of about 700 kHz is used to separate the two frequency bands, in alternative embodiments the guard band could be changed or the frequency bands for transmitting and receiving could be changed. In further alternative embodiments, it is also possible to interleave the various transmit and receive frequencies.

In preferred embodiments of the present invention, the PNIs and the interface circuit are frequency agile and therefore adjustable over the entire frequency band from about 1 to 4 MHz. The transmit and receive frequencies for the PNIs are assigned through a low-speed control channel (explained in further detail below). Because the PNIs are frequency agile, each PNI is physically identical to every other PNI. One benefit to a frequency agile system is that communication channels can be moved away from short-wave radio broadcasts or other sources of interference. In alternative embodiments, however, the PNIs and interface circuit are tuned to a fixed transmit and receive frequency range.

FIG. 3 illustrates a customer premises communication system including a simplified block diagram of the host device 20 and a PNI 22 according to an embodiment of the present invention. As noted above, the external communication link 12 may contain voDSL, high-speed DSL Internet access, POTS, and other DSL- based communications.

In one example application of preferred embodiments of the present invention, within the telco CO 14 up to four channels of analog audio information 164 representing four telephone conversations may be received by a voDSL provider

166 and converted to voDSL data 168. The voDSL data 168 is then communicated over the exterior communications link 12 and is received by the host device 20. The voDSL data 168 (a form of ATM protocol data) is converted by a DSL modem 258 to digital ATM data. Processor 150 takes the digital ATM data and separates it into AAL5 protocol data (Internet/network data) and up to four channels of AAL2 protocol data (voice) 170. Each channel of AAL2 protocol data 170 is then used to modulate a carrier in an FSK transmitter 154 in the interface circuit 152 and generate a host transmit signal 216. Each host transmit signal 216 is then broadcast to the PNIs 22 over the interior communications link 16 at a transmit frequency corresponding to a particular channel. The communication of multiple telephone conversations over a single communication link is known as derived voice or distributed voice.

The host transmit signals 216 are then received by each PNI 22 through a transfer relay 228 (explained in further detail below) and delay line 234 (explained in further detail below). The host transmit signals are then filtered by a diplexer 252 and demodulated by an FSK receiver 160 tuned to a receive frequency unique to that PNI 22. The demodulated host transmit signal is then converted to analog audio information by a CODEC 162, passed through a station line interface circuit (SLIC) 230 (explained in further detail below) and the transfer relay 228, and finally sent to the telephone (device 18) connected to the PNI 22. Note that only the PNI 22 having an FSK receiver tuned to the proper channel will actually recover the analog audio information.

Continuing the present example, an overview of the return communication path from each telephone to the telco CO 14 will now be described. Again referring to FIG. 3, for each of up to four telephones, analog audio information 254 from a device 18 such as a telephone is received by a corresponding PNI 22, and passed through the transfer relay 228 and SLIC 230. The analog audio information is then converted to digital AA2 protocol data by CODEC 162, and the digital AA2 protocol data is used to modulate a carrier in an FSK transmitter 158 to generate a PNI transmit signal 298. The PNI transmit signal 298 is then filtered by diplexer 252, passed through delay line 234 and transfer relay 228, and broadcast to the host device 20 over the interior communications link 16. The PNI transmit signals 298 for each of the PNIs 22 are then received in the host device 20 by four FSK receivers 156, each FSK receiver tuned to a particular receive frequency, and demodulated into up to four separate channels of AAL2 protocol data 172. The AAL2 protocol data 172 is then converted by processor 150 into digital ATM data, converted by the DSL modem 258 into up to four voDSL signals 174, and communicated over the exterior communications link 12. The voDSL signals 174 are then received by the voDSL provider 166, where they are converted back to analog audio information.

FIG. 4 illustrates a block diagram of an example interface circuit 152 within the host device 20 according to an embodiment of the present invention. A description of the receive path will now be provided. A PNI transmit signal 298, which may include communications from multiple PNIs, is received by the host device 20 over the internal communication link 16. In preferred embodiments, up to four communication channels may be received from four PNIs, with carrier frequencies of 2 MHz, 2.2 MHz, 2.4 MHz, and 2.6 MHz, providing a channel separation of 200 kHz from the carrier frequencies of adjacent channels. It should be understood, however, that in alternative embodiments the carrier frequencies and channel separation may be different. The PNI transmit signal 298 is first filtered by a diplexer 180 which separates out the receive band frequencies to produce a host receive signal 182. The host receive signal 182 is then filtered by a pre-selector filter 186. The pre-selector filter 186 acts as an impedance-adaptive pre-selector, or a bandpass filter that performs impedance translation. In preferred embodiments, the pre-selector filter 186 has a narrow passband that covers the receive band frequencies, and has an impedance that is matched to the signal impedance (approximately 39 ohms) and is mismatched with respect to the noise impedance (approximately 200-250 ohms). The net result is an improvement is the noise margin. The filtered host receive signal is then amplified by a receive low noise amplifier (LNA) 184 to produce a buffered host receive signal 196.

The buffered host receive signal 196 is then communicated to four FSK receivers 156, one FSK receiver 156 for each communication channel. In preferred embodiments, each FSK receiver 156 includes two filters 306 for creating a bandpass filter with good selectivity (shape).

Each FSK receiver 156 receives a local oscillator (LO) frequency 192 from a local oscillator 194 (one for each channel). In preferred embodiments of the present invention, each local oscillator 194 is a phase-locked-loop (PLL) voltage-controlled oscillator (VCO) that generates LO frequencies 10.7 MHz greater than the center frequencies of the receive channels and thus, in the example of FIG. 4, four local oscillators 194 will generate LO frequencies of 12.7 MHz, 12.9 MHz, 13.1 MHz, and 13.3 MHz. In preferred frequency-agile embodiments, a processor 150, through control logic 292, may configure each local oscillator 194 to produce one of the above-identified frequencies by generating a receive channel select control signal 290. The receive channel select control signal 290 causes dividers 294 in the feedback path of the PLL VCO to change, which will cause the LO frequency 192 of the PLL VCO to change. In preferred embodiments, the dividers 294 are located in a programmable logic device (PLD) 296. The PLL VCO is phase-locked to a reference source 222 which, in preferred embodiments, generates a 32 MHz signal. It should be understood, however, that in alternative embodiments the reference source and mixing frequencies may be different to correspond with different channel frequencies. In preferred embodiments of the present invention, each FSK receiver 156 demodulates the buffered host receive signal 196 by subtracting the buffered host receive signal 196 from the LO frequency 192 to produce a modulated MHz IF signal. This IF signal is amplified, limited and sent to a detector, which detects the frequency shifts in the IF signal. The output of the detector is then passed through a differential amplifier configured as a digital slicer to produce demodulated digital AA2 protocol data 172. The AA2 protocol data 172 generated by each FSK receiver 156 is then communicated to the processor 150 through control logic 292.

Again referring to FIG. 4, a description of the transmit path will now be provided. In preferred embodiments of the present invention, there are four FSK transmitters 154 in each interface circuit 152, one FSK transmitter for each channel. Within each FSK transmitter 154 is a PLL VCO 210. In preferred frequency-agile embodiments, a processor 150, through control logic 292, may configure each PLL VCO 210 to produce a unique host transmit frequency by generating a transmit channel select control signal 300. The transmit channel select control signal 300 causes dividers 304 in the feedback path of the PLL VCO 210 to change, which will cause the transmit frequency of the PLL VCO 210 to change. In preferred embodiments, the host transmit frequencies are 3.3 MHz, 3.5 MHz, 3.7 MHz, and 3.9 MHz, providing a channel separation of 200 kHz from the center frequencies of adjacent channels. In further preferred embodiments, the dividers 304 are located in a programmable logic device (PLD) 296. The PLL VCO is phase-locked to a reference source 222 which, in preferred embodiments, generates a 32 MHz signal. It should be understood, however, that in alternative embodiments the reference source and LO frequencies may be different to correspond with different channel frequencies.

In preferred embodiments of the present invention, one channel of AAL2 protocol data 170 from processor 150 is communicated to each PLL VCO 210 within each FSK transmitter 154, through control logic 292. In preferred embodiments, the host transmit frequency is modulated by adding the digital pulses of the AAL2 protocol data 170 to the correction voltage (VT) 302 of the PLL VCO 210. In alternative embodiments not illustrated in FIG. 4, the digital pulses of the AAL2 protocol data 170 are used to toggle the least significant bits of the dividers 304, which causes a modulation of the host transmit frequency.

Each of the modulated host transmit frequencies is then amplified by an amplifier 212 and summed together through resistors 214 to produce a composite host transmit signal 216. The host transmit signal 216 is then filtered by the diplexer

180, and then transmitted to the PNIs over the internal communication link 16. It should be understood that the FSK modulation indicated in FIG. 4 is merely exemplary, and that in alternative embodiments other modulation techniques may be used. It should also be noted that the overall frequency plan of the transmitter 154 and receiver 156 of FIG. 4 according to preferred embodiments of the present invention, including the selection of a 32 MHz reference source 222, was designed to provide channel spacings of 200 kHz and produce local oscillator frequencies that could be divided down and phase-locked to a single reference source. In addition, the frequency plan of FIG. 4 is designed to accommodate a four PNI communication system. However, in alternative embodiments designed to accommodate a number of PNIs other than four, the frequency plan would be different.

For example, because of the bandwidth required for voice communications, ADSL can support up to 16 voDSL channels for 16 telephones. However, if more than 4 voDSL channels are in simultaneous use, ADSL Internet service will have to cut back. The tradeoff between telephone service and Internet service is one of limited bandwidth resources. Thus, if 16 telephones are in simultaneous use, there would be no ADSL Internet access capability. Nevertheless, 16 telephone capability may be a practical application for businesses that have multiple ADSL lines coming into their offices. One ADSL line may be used for Internet access and the other

ADSL line may be used to provide 16 telephone voDSL capability.

The 16 telephone limitation described above is for full telephone service, which communicates at a rate of 64 kilobytes per second. However, because voice data may be compressed, various compression techniques may be used wherein only 32 or 16 kilobytes are necessary to communicate voice data. Thus, alternative embodiments of the present invention may actually go beyond even 16 PNI capability. FIG. 4 (not including the specific frequency plan shown in FIG. 4) is therefore generally applicable to systems which have other than four PNI channel capability, except that there would be a different number of receivers and transmitters than indicated in FIG. 4.

It should be further understood that even with the transmitter and receiver design of FIG. 4, which only supports four simultaneous PNI communication channels, it is possible to connect more than four PNIs and four telephones to the internal communication link within the premises. However, once four channels are in use, the remaining telephones will be inoperable. For example, if four people are talking on four separate telephones, the other telephones would simply receive busy signals.

FIG. 5 is a spreadsheet illustrating the frequency plan according to preferred embodiments of the present invention, wherein the second harmonic of the transmit frequencies and the second harmonic of the receive frequencies do not interfere with the transmit frequencies and the receive frequencies. The combination of having 200 kHz channel spacing and maintaining a single reference oscillator frequency also eliminates the interference that would occur if multiple oscillators were employed at different frequencies, all beating against each other.

The circuitry of a PNI will now be described. Referring again to FIG. 3, each PNI 22 includes a first RJ-11 connector (not shown in FIG. 3) for connecting to the internal communication link 16, and a second RJ-11 connector (not shown in

FIG. 3) for connecting to a device 18 (e.g. telephone). Through these connectors, the internal communication link 16 and the telephone are connected to a transfer relay 228. Under normal conditions, the PNI 22 receives power for its electronics from the household AC power source, and power and transmit/receive signals are provided to the telephone through the PNI 22. However, during AC power outages, the PNI 22 becomes inoperable, and the transfer relay 228 automatically connects the telephone to the internal communication link 16 to draw power from the external communication link (regular telephone wiring) and provide POTS.

In addition, within the PNI 22 is a station line interface circuit (SLIC) 230 coupled to the CODEC 162. The SLIC 230 is a standard telephone interface chip that is well-known to those skilled in the art, and converts from two-wire telephone wiring to four- wire telephone wiring, rings the telephone, determines when the telephone is on-hook or off-hook, and the like.

FIG. 6 illustrates a block diagram of an example FSK transmitter 158 and FSK receiver 160 within a PNI 22 according to an embodiment of the present invention. The circuit of FIG. 6 is similar to the interface circuit of FIG. 4, except that the receive frequencies of FIG. 4 become the transmit frequencies in FIG. 6, and the transmit frequencies of FIG. 4 become the receive frequencies in FIG. 6. In addition, in FIG. 6, each PNI, although frequency-agile in preferred embodiments, is tuned to a particular transmit and receive frequency, so there is only one local oscillator 328, one FSK receiver 160, one PLL VCO 308, and one FSK transmitter

158 in FIG. 6.

A description of the receive path will now be provided. A host transmit signal 216 is received by the PNI 22 over the internal communication link 16. In preferred embodiments, the host transmit signal 216 may contain up to four communication channels with carrier frequencies of 3.3 MHz, 3.5 MHz, 3.7 MHz, and 3.9 MHz, providing a channel separation of 200 kHz from the carrier frequencies of adjacent channels. It should be understood, however, that in alternative embodiments the carrier frequencies and channel separation may be different. The host transmit signal 216 is first filtered by a diplexer 252 which separates out the receive band frequencies to produce a PNI receive signal 330. The PNI receive signal 330 is then filtered by a pre-selector filter 332. The pre-selector filter 332 acts as an impedance-adaptive pre-selector, or a bandpass filter that performs impedance translation. In preferred embodiments, the pre-selector filter 332 has a narrow passband that covers the receive band frequencies, and has an impedance that is matched to the signal impedance (approximately 39 ohms) and is mismatched with respect to the noise impedance (approximately 200-250 ohms). The net result is an improvement is the noise margin. The filtered PNI receive signal is then amplified by a receive low noise amplifier (LNA) 334 to produce a buffered PNI receive signal 336. The buffered PNI receive signal 336 is then communicated to an FSK receiver 160. In preferred embodiments, the FSK receiver 160 includes two filters 338 for creating a bandpass filter with good selectivity (shape).

The FSK receiver 160 receives a local oscillator (LO) frequency 340 from a local oscillator 328. In preferred embodiments of the present invention, the local oscillator 328 is a phase-locked-loop (PLL) voltage-controlled oscillator (VCO) that generates LO frequencies 10.7 MHz greater than the center frequencies of the receive channels and thus, in the example of FIG. 6, the local oscillator 328 will generate LO frequencies of 14 MHz, 14.2 MHz, 14.4 MHz, and 14.6 MHz. In preferred frequency-agile embodiments, control logic 310 will configure local oscillator 328 to produce one of the above-identified frequencies by generating a receive channel select control signal 288. The receive channel select control signal 288 causes dividers 340 in the feedback path of the PLL VCO to change, which will cause the LO frequency 340 of the PLL VCO to change. In preferred embodiments, the dividers 340 are located in a programmable logic device (PLD) 316. The PLL

VCO is phase-locked to a reference source 318 which, in preferred embodiments, generates a 32 MHz signal. It should be understood, however, that in alternative embodiments the reference source and mixing frequencies may be different to correspond with different channel frequencies. In preferred embodiments of the present invention, each FSK receiver 160 demodulates the buffered PNI receive signal 336 by subtracting the buffered PNI receive signal 336 from the LO frequency 340 to produce a modulated MHz IF signal. This IF signal is amplified, limited and sent to a detector, which detects the frequency shifts in the IF signal. The output of the detector is then passed through a differential amplifier configured as a digital slicer to produce demodulated digital AA2 protocol data 342. The AA2 protocol data 342 generated by the FSK receiver 160 is then communicated to the CODEC 162 through control logic 310.

A description of the transmit path will now be provided. In embodiments of the present invention, there is one FSK transmitter 158 in each PNI 22. Within the FSK transmitter 158 is a PLL VCO 308. In preferred frequency-agile embodiments, control logic 310 may configure each PLL VCO 308 to produce a unique PNI transmit frequency by generating a transmit channel select control signal 312. The transmit channel select control signal 312 causes dividers 314 in the feedback path of the PLL VCO 308 to change, which will cause the host transmit frequency of the PLL VCO 308 to change. In preferred embodiments, the host transmit frequencies are 2 MHz, 2.2 MHz, 2.4 MHz, and 2.6 MHz, providing a channel separation of 200 kHz from the center frequencies of adjacent channels. In further preferred embodiments, the dividers 314 are located in a programmable logic device (PLD) 316. The PLL VCO 308 is phase-locked to a reference source 318 which, in preferred embodiments, generates a 32 MHz signal. It should be understood, however, that in alternative embodiments the reference source and LO frequencies may be different to correspond with different channel frequencies.

Referring again to FIG. 3, in preferred embodiments of the present invention, analog audio information 254 from a device 18 such as a telephone is received by a corresponding PNI 22, and passed through the transfer relay 228 and SLIC 230. The analog audio information is then converted to digital AA2 protocol data by CODEC 162. Referring now to FIG. 6, the AAL2 protocol data 320 is communicated to the PLL VCO 308 through control logic 310. In preferred embodiments, the PNI transmit frequency is modulated by adding the digital pulses of the AAL2 protocol data 320 to the correction voltage (VT) 322 of the PLL VCO 308. In alternative embodiments not illustrated in FIG. 6, the digital pulses of the AAL2 protocol data 320 are used to toggle the least significant bits of the dividers 314, which causes a modulation of the host transmit frequency.

The modulated PNI transmit frequency is then attenuated by a pad 324 and amplified by an amplifier 326 to produce a PNI transmit signal 298. The PNI transmit signal 298 is then filtered by the diplexer 252 and transmitted to the host device 20 over the internal communication link 16.

It should be understood that the FSK modulation indicated in FIG. 6 is merely exemplary, and that in alternative embodiments other modulation techniques may be used. It should also be noted that the overall frequency plan of the FSK transmitter 158 and FSK receiver 160 of FIG. 6 according to preferred embodiments of the present invention, including the selection of a 32 MHz reference source 318, was designed to provide channel spacings of 200 kHz and produce local oscillator frequencies that could be divided down and phase-locked to a single reference source. In addition, it should be understood that the local oscillator, transmit, and receive frequencies indicated on FIG. 6 are merely exemplary, and that in alternative embodiments other frequencies may be used. In addition, the frequency plan of FIG. 6 is designed to accommodate a four channel communication system. However, in alternative embodiments designed to accommodate a number of channels other than four, the frequency plan would be different.

In preferred embodiments of the present invention, the host device assigns frequency channels as links to PNIs are established, and thus keeps track of which channels are free, and which have already been assigned. Once all four frequency channels are being used, a busy signal would be returned to a caller who is trying to access the premises telephone system. In preferred embodiments, control information, including channel selection information, is passed between the host device and PNIs across a low-speed virtual control channel.

FIG. 6a illustrates the digital communication stream occurring in four host transmit communication channels 344, including a low-speed virtual control channel superimposed over the four communication channels according to embodiments of the present invention. It should be understood, however, that FIG. 6a is merely exemplary, and that other communication formats and timing may be employed without departing from the scope of the present invention. In order to transmit voice, an 8 kHz sampling rate and 8 bits of data per sample is generally required, and thus 64 kilobytes of data per second are required. In one embodiment of the present invention, 44 bytes of data are transmitted in a single packet in about 5.5 milliseconds, or approximately one byte every 125 microseconds. In embodiments of the present invention two-bytes of control information 346 are transmitted for every 44 bytes of data. This control information is being transmitted over every channel at all times, even when a particular channel is idle. Multiple bytes of control information may be required to form a single control word. This continuous stream of control information comprises a low-speed virtual control channel. It should be understood, however, that the timing of the four channels 344 is not synchronized, so the control information and data information in the various communication channels may be staggered. Within each control word is information identifying a targeted PNI for the control word. Because the control information is continuously being transmitted over all channels, all PNIs will continuously be reading the control information. When the control logic (see reference character 286 in FIG. 6) within a PNI detects that it is the target of a control word, the PNI will respond to the control word. For example, the PNI may be directed to change to another channel, upon which the control logic 286 will send control signals to the PLD which will cause the VCOs to change frequency.

Similarly, the PNIs may communicate two-byte control information over the PNI transmit communication channels. Control information from the PNIs may include heartbeating, which would inform the host device that the PNI is alive but idle. The PNI might also communicate information indicating which channel it is currently tuned to. In this manner, the host device can determine which channels are in use, and which are idle. In embodiments of the present invention illustrated in FIG. 6a, each byte starts out with a start bit 348 followed by eight bits of data 350. Following the eight bits of data is a control bit 352 which identifies whether this particular byte is a virtual control channel byte or a data byte. However, it should again be understood that FIG. 6a is only exemplary, and that many other formats are possible. Referring again to FIG. 3, it is readily apparent that the internal communication link 16 within a typical home or business will not be a single line, but will rather contain multiple tie-ins or branches. Furthermore, these tie-ins are not of uniform length because of the variety of placements of telephone jacks within the premises. In addition, in preferred embodiments the internal communication link 16 comprises a twisted pair which, by itself, would have an impedance of about 75 ohms. However, the branches in the internal communication link 16 create impedance mismatches, which in turn create quarter-wave signal nulls or "suck- outs" as high as -60 dB at certain frequencies. Signals being communicated over the internal communication link 16 at those frequencies may be severely attenuated. For example, if a tie-in created a suck-out at 3.3 MHz, and a PNI receive frequency is centered at 3.3 MHz, that channel may not be properly received by the PNI. More generally, in preferred embodiments of the present invention wherein communications between the host device 20 and the PNIs 22 occur within the 1 to 4 MHz band, any suck-outs that exist between 1 and 4 MHz may cause problems.

As illustrated in FIG. 7, suck-outs resulting from ties-ins having a length of about 100-200 feet occur at about 1.1 MHz (see dotted line and reference character 232 in FIG. 7), which is in a frequency band above the 1 MHz upper end of the

ADSL band, yet below the approximately 1.5 MHz lower end of communications between the host device 20 and the PNIs 22. Thus, preferred embodiments of the present invention move these suckouts to about 1.1 MHz by adding a delay element to the distal end of each tie-in connected to a PNI. In preferred embodiments illustrated in FIG. 8, each delay element 234 is a delay line comprised of five capacitors and eight inductors. However, in alternative embodiments, other combinations of capacitors and inductors may be used, and more generally, other types of delay lines or other synthetic line-lengthening circuits capable of passing telephone currents may also be used. In addition, the delay element 234 may comprise an approximately 100-foot length of telephone wire. In preferred embodiments, the delay element 234 is placed within each PNI 22, as illustrated in FIG. 3, and acts as the equivalent of an approximate 100-foot extension to the existing telephone line physical wiring. The net effect of the additional length created by the delay line is to push all of the suck-outs down to about 1.1 MHz, and out of the frequency bands of interest. Note, however, that in alternative embodiments, the delay element 234 may be designed to push the suck-outs to other non- interfering frequencies. More generally, the delay element 234 will be designed to push the suck-outs to a non-interfering frequency, regardless of the selection of transmit and receive frequencies. It should be understood that standard telephone service (POTS) will be unaffected by embodiments of the present invention. As illustrated in FIG. 3, POTS signals 262 are communicated through the telco CO 14 and are passed directly from the exterior communication link 12 to the interior communication link 16 without any processing by the host device 20. One or more telephones 280 connected directly to the interior communication link 20 can receive the standard telephone service.

The descriptions of embodiments of the present invention provided above focused on the communication of voice data. However, in another example application of preferred embodiments of the present invention illustrated in FIG. 3, DSL Internet data 256 is communicated through the telco CO 14 and is received by the host device 20 over the exterior communications link 12. The DSL Internet data 256 (ATM protocol data running on DSL) is converted by the DSL modem 258 to digital ATM data. Processor 150 takes the digital ATM data and separates out

AAL5 protocol data (Internet/network data) from AAL2 protocol data (voice). The Internet/network data is then sent to a HomePNA/Ethernet Interface 264, which physically connects the Internet/network data to the interior communications link 16 and an Ethernet port 266. PCs connected to Ethernet port 266 through an Ethernet Local Area Network (LAN), or PCs connected to the interior communications link

16 through a Network Interface Card (NIT) (see reference character 282) may then receive the Internet/network data.

In the return path, PCs connected to Ethernet port 266 or the interior communications link 16 may send AAL2 protocol Internet/network data through the HomePNA/Ethernet Interface 264 to the processor 150, where it is converted into digital ATM protocol data, converted by the ADSL modem 258 into DSL Internet data 256, and communicated over the exterior communications link 12. The DSL Internet data 256 is then converted to HTTP protocol data by a DSL provider 268 and communicated over the Internet. It should be understood that PCs connected to an Ethernet LAN coupled to the Ethernet port 266 may communicate with each other over the Ethernet using Ethernet protocols without using the host device 20, and PCs connected to the interior communications link 16 through a NIT may communicate with each other over the interior communications link 16 using HomePNA protocols without using the host device 20. Additionally, PCs coupled to the Ethernet LAN through the

Ethernet port 266 may communicate with PCs coupled to the interior communications link 16 through the HomePNA/Ethernet Interface 264 in the host device 20. A PC may also be connected directly to the host device 20 through RS- 232 connector 260, where it may communicate with PCs coupled to the interior communications link 16 through the HomePNA/Ethernet Interface 264, or may communicate with PCs coupled to the Ethernet LAN through the Ethernet port 266. Although the previous discussion focused on the communication and distribution of information over standard twisted pair telephone wiring (the exterior communications link 12 and the interior communications link 16), the host device 20 according to alternative embodiments of the present invention may receive data from sources other than telephone wiring. For example, FIG. 3 illustrates that the host device 20 may, as an alternative to, or in addition to the ADSL modem 258, include a cable modem 270 or satellite modem 272 to receive data over standard cable TV wiring or over satellite audio/video broadcasts and convert the data to digital ATM protocol data, where it can be further processed by the host device 20 as described above.

Furthermore, the host device 20 may, as an alternative to telephone wiring, communicate with and control other devices and systems (e.g. telephones, computers, appliances, audio/video equipment, security systems, lighting control systems, environment control systems such as heating and air conditioning, and the like) through customer premise AC power lines, wireless communications, or the like. For example, in alternative embodiments of the present invention the FSK transmitters and receivers in the host device 20 and PNIs 22 could be modified to add amplifiers and antennas which would enable voice communications using wireless techniques well-understood by those skilled in the art. Furthermore, NITs could be easily modified to add wireless FM transmitters and receivers which would enable data communications between PCs and the host device using wireless techniques well-understood by those skilled in the art.

In addition, the host device 20 may be adapted to communicate with PNIs over existing AC power wiring. At frequencies of less than 100 Hz, the impedance of AC power wiring is essentially zero. At a few hundred kHz, the impedance begins to rise rapidly because AC power wiring is single-ended. However, from around 25 kHz to about 250 kHz the impedance is essentially constant at about 10 ohms. By matching load and line impedances, signals can be communicated over the AC power wiring (on one side of an isolation transformer) within a frequency band of about 25 kHz to 250 kHz with little loss.

Therefore, in alternative embodiments of the present invention illustrated in FIG. 9, the host device 20 interface circuit 152 is transformer coupled to the AC power wiring rather than the interior communication link 16. FM transmit signals are communicated over the AC power wiring between the host device and PNIs transformer coupled to the AC power wiring. The host device interface circuit 152 is similar to that shown in FIG. 4, except that the transmitter and receiver components would be selected to account for transmit and receive frequencies preferably in the range of 25 kHz to 250 kHz. In addition, the PNI circuit diagram is similar to that shown in FIG. 6, except that the transmitter and receiver components would be selected to account for transmit and receive frequencies preferably in the range of 25 kHz to 250 kHz. Because of the utility of communicating signals over AC power wiring, power line control standards such as CEBus (see, e.g., the CEBus standard EIA-600) or X-10 (see, e.g., the X-10 Technical Specification) have been developed. Thus, in preferred embodiments, the transmit and receive frequencies of the host device and PNIs would be selected to avoid the frequency bands utilized by CEBus and X-10 (e.g. approximately 38 kHz for CEBus, 120 kHz for X-10).

Control modules for transmitting CEBus or X-10 compatible control signals over a transformer-coupled AC power line have been developed and are commercially available. Corresponding interface modules that plug into the AC power line, receive control signals from the control modules, and control electronics connected to the interface modules have also been developed and are commercially available. The host device and processor of embodiments of the present invention can be readily adapted by those skilled in the art to interface with, and control, the control module of existing power line control systems.

For example, in an alternative embodiment of the present invention illustrated in FIG. 3, CEBus control data from a user's remote Web browser is converted to

DSL Internet data 256 by a DSL provider 268, and then communicated through the telco CO 14 over the exterior communications link 12 to the host device 20. The DSL Internet data 256 (ATM protocol data running on DSL) is converted by the DSL modem 258 to digital ATM data. Processor 150 takes the digital ATM data and separates out CEBus protocol data. The CEBus protocol data is then sent to a

CEBus Interface 274, which converts the CEBus protocol data to CEBus control signals and transmits these control signals over the transformer-coupled AC power wiring 276. Devices 284 connected to the AC power wiring 276 through a CEBus interface module 278 may then receive and respond to the CEBus control signals. A similar communication path would be employed for X-10 devices.

In the return path, control or feedback signals from the CEBus interface modules 278 would be received by the CEBus Interface 274 and forwarded to the processor 150, which would convert the CEBus protocol data to digital ATM data. The digital ATM protocol data would be converted by the ADSL modem 258 to DSL Internet data 256 and transmitted over the exterior communication link 12. The DSL Internet data 256 is received by the DSL provider 268 and converted to HTTP for communication over the Internet to a user Web browser or organizational Web server (such as in an appliance company's service department).

Therefore, embodiments of the present invention provide a system and method for simultaneously receiving DSL communications, POTS, and other information, and distributing this information to and from devices within the customer premises over a single twisted pair telephone line without interference, and without interfering with HPNA or other protocol communications that may also be present on the single twisted pair telephone line. Embodiments of the present invention also utilize digital communications to increase noise immunity, and enable the changing of communication frequencies (channels). In addition, embodiments of the present invention utilize existing twisted pair household telephone wiring, which minimizes the need for rewiring household telephone lines. Furthermore, the aforementioned system and method may be implemented in devices that need not be placed outside, thereby reducing physical robustness and durability requirements, and need not be installed by professional installers, thereby minimizing the number of truck rolls and installation and maintenance costs. Furthermore, embodiments of the present invention also provide a system and method for distributing communications (e.g. , telephone calls, data transfers, appliance or other device commands and status signaling) to and from different types of customer premises equipment (CPE) and controllable devices via different media such as power lines, fiber optic links, coaxial cable, wireless links, and other network wiring, using various types of communication protocols.

Claims

What is claimed is:

1. A system for communicating with multiple devices over an interior communication link, the system comprising: a host device couplable to the interior communication link for transmitting and receiving digital information over the interior communication link using a plurality of first communication channels; and a plurality of peripheral node interface circuits (PNIs) couplable to the interior communication link, each PNI for receiving digital information from the host device over a particular first communication channel, and for transmitting digital information to the host device over that first communication channel.

2. A system as recited in claim 1, wherein the digital information is digital voice data.

3. A system as recited in claim 1, wherein a device may be coupled to each PNI for receiving analog information from the PNI, and for transmitting analog information to the PNI.

4. A system as recited in claim 3, wherein the device is a telephone.

5. A system as recited in claim 1 : each first communication channel comprising a first FM communication channel having a unique host transmit frequency and host receive frequency; the host device having a plurality of host transmitter and receiver pairs, each host transmitter for modulating the host transmit frequency of a particular first FM communication channel with digital information to generate a host transmit signal, and each host receiver for demodulating a PNI transmit signal modulated by digital information at the host receive frequency of that first FM communication channel; and each PNI having a PNI receiver tuned to the host transmit frequency of a particular first FM communication channel for demodulating the host transmit signal transmitted over that first FM communication channel, and a PNI transmitter tuned to the host receive frequency of that first FM communication channel for modulating the PNI transmit signal transmitted over that first FM communication channel.

6. A system as recited in claim 5, wherein the plurality of host transmitter and receiver pairs in the host device are frequency agile, and the PNI receiver and PNI transmitter in each PNI are frequency agile.

7. A system as recited in claim 6: the digital information for communication over each first FM communication channel comprising an alternating serial stream of control bytes and data packets, one or more control bytes comprising a control word, the control words being communicated at any one period of time over any of the first FM communication channels is identical; and each PNI having control logic including a processor for interpreting the control words; wherein each PNI can be tuned to a particular first FM communication channel according to the interpreted control words.

8. A system as recited in claim 5, wherein FSK modulation is employed by the host device and the plurality of PNIs.

9. A system as recited in claim 5, wherein the interior communication link is a twisted pair telephone line.

10. A system as recited in claim 9, the host transmit and host receive frequencies of the plurality of first FM communication channels occurring outside a frequency range occupied by POTS, ADSL, or HomePNA.

11. A system as recited in claim 9, the host transmit and host receive frequencies of the plurality of first FM communication channels occurring in a frequency range between about 1 MHz to about 5 MHz.

12. A system as recited in claim 9: the host receive frequencies of the plurality of first FM communication channels occurring in a frequency range between about 2 MHz to about 2.6 MHz; and the host transmit frequencies of the plurality of first FM communication channels occurring in a frequency range between about 3.3 MHz to about 3.9 MHz.

13. A system as recited in claim 5: the host device including a host reference source and a host receiver PLL VCO for each host receiver, each host receiver PLL VCO coupled and locked to the host reference source for generating a host local oscillator frequency; each host receiver coupled to one host receiver PLL VCO for demodulating the PNI transmit signal using the host local oscillator frequency; and each host transmitter including a host transmitter PLL VCO coupled and locked to the host reference source for generating the host transmit frequency, and coupled for modulating the host transmit frequency with digital information to be transmitted over the shared communication link, the modulated host transmit frequency comprising the host transmit signal.

14. A system as recited in claim 13, wherein the digital information is added to a correction voltage of the host transmitter PLL VCO to modulate the host transmit frequency.

15. A system as recited in claim 13, wherein the digital information modifies a feedback divider in the host transmitter PLL VCO to modulate the host transmit frequency.

16. A system as recited in claim 13, further including four first FM communication channels; wherein the host reference source is 32 MHz, the host receive frequencies of the four first FM communication channels are 2 MHz, 2.2 MHz, 2.4 MHz, and 2.6 MHz, the host transmit frequencies of the four first FM communication channels are 3.3 MHz, 3.5 MHz, 3.7 MHz, and 3.9 MHz, and the host local oscillator frequencies of the four receive PLL VCOs are 12.7 MHz, 12.9 MHz, 13.1 MHz, and 13.3 MHz.

17. A system as recited in claim 13, each PNI further including: a PNI reference source and a PNI receiver PLL VCO, the PNI receiver PLL VCO coupled and locked to the PNI reference source for generating a PNI local oscillator frequency; a PNI receiver coupled to the PNI receiver PLL VCO for demodulating the host transmit signal using the PNI local oscillator frequency; and a PNI transmitter PLL VCO coupled and locked to the PNI reference source for generating the host receive frequency, and coupled for modulating the host receive frequency with digital information to be transmitted over the shared communication link, the modulated host receive frequency comprising the PNI transmit signal.

18. A system as recited in claim 16, wherein the digital information is added to a correction voltage of the PNI transmitter PLL VCO to modulate the host receive frequency.

19. A system as recited in claim 17, wherein the digital information modifies a feedback divider in the PNI transmitter PLL VCO to modulate the host receive frequency.

20. A system as recited in claim 17, further including four first FM communication channels; wherein the PNI reference source is 32 MHz, the host receive frequencies of the four first FM communication channels are 2 MHz, 2.2 MHz, 2.4 MHz, and 2.6

MHz, the host transmit frequencies of the four first FM communication channels are 3.3 MHz, 3.5 MHz, 3.7 MHz, and 3.9 MHz, and the PNI local oscillator frequencies of the four receive PLL VCOs are 14 MHz, 14.2 MHz, 14.4 MHz, and

14.6 MHz.

21. A system as recited in claim 5, wherein the shared communication link is AC power wiring transformer-coupled to the host device.

22. A system as recited in claim 21, the host transmit and host receive frequencies of the plurality of first FM communication channels occurring in a frequency range outside a frequency range occupied by CEBus or X-10.

23. A system as recited in claim 21, the host transmit and host receive frequencies of the plurality of first FM communication channels occurring in a frequency range between about 25 kHz to about 250 kHz.

24. A system as recited in claim 5, the host device couplable to an external communication link for transmitting and receiving digital information over the external communication link using a plurality of second communication channels.

25. A system as recited in claim 24, wherein the external communication link is a twisted pair telephone line.

26. A system as recited in claim 24, wherein the digital information transmitted and received over the external communication link is communicated according to DSL or voDSL protocols.

27. A system as recited in claim 24, wherein the external communication link is a coaxial cable.

28. A system as recited in claim 24, wherein the external communication link is a wireless communication link.

29. A system as recited in claim 26, the host device further including: a DSL modem coupled to the external communication link for converting

DSL data received over the external communication link to incoming ATM data, and for converting outgoing ATM data to be transmitted over the external communication link to DSL data; and a processor coupled to the DSL modem for separating out incoming voice data from the incoming ATM data, and for converting outgoing voice data to outgoing ATM data; wherein the processor is coupled for communicating the incoming voice data to the plurality of host transmitter and receiver pairs for transmission over the internal communication link, and for receiving outgoing voice data from the plurality of transmitter and receiver pairs.

30. A system as recited in claim 29, the processor for separating out incoming Internet/network data from the incoming ATM data, and for converting outgoing Internet/network data to outgoing ATM data; wherein the processor is further coupled for communicating the incoming Internet/network data to PCs coupled to the internal communication link, an Ethernet LAN, or an RS-232 connector, and for receiving outgoing Internet/network data from the PCs coupled to the internal communication link, an Ethernet LAN, or an RS-232 connector.

31. A system as recited in claim 29, the processor for separating out incoming AC power line control data from the incoming ATM data, and for converting outgoing AC power line control data to outgoing ATM data; wherein the processor is further transformer-coupled for communicating the incoming AC power line control data to devices coupled to an AC power line, and for receiving outgoing AC power line control data from the devices coupled to the AC power line.

32. A method for communicating with multiple devices over an interior communication link, the method comprising the steps of: transmitting and receiving digital information over the interior communication link through a plurality of first communication channels using a host device; and receiving digital information from the host device over the plurality of first communication channels and transmitting digital information to the host device over the plurality of first communication channels using a plurality of peripheral node interface circuits (PNIs), each PNI for receiving digital information from the host device and transmitting digital information to the host device over a unique first communication channel.

33. A method as recited in claim 32, the digital information comprising digital voice data.

34. A method as recited in claim 32, further including the step of communicating analog information from a PNI to a device coupled to that PNI, and receiving analog information into that PNI from the device.

35. A method as recited in claim 34, wherein the device is a telephone.

36. A method as recited in claim 32, further including the steps of: transmitting and receiving digital information over the internal communication link through a plurality of first FM communication channels, each first FM communication channel having a unique host transmit frequency and host receive frequency; modulating the host transmit frequencies of the plurality of first FM communication channels with digital information using a plurality of host transmitters to generate a plurality of host transmit signals, and demodulating a plurality of PNI transmit signals modulated by digital information at the host receive frequencies of the plurality of first FM communication channels using a plurality of host receivers; and demodulating the host transmit signals transmitted over the plurality of first FM communication channels using a plurality of PNI receivers tuned to the host transmit frequencies of the plurality of first FM communication channels, and modulating the plurality of PNI transmit signals transmitted over the plurality of first FM communication channels using a plurality of PNI transmitters tuned to the host receive frequencies of the plurality of first FM communication channels.

37. A method as recited in claim 36, further including the step of selectably tuning host transmitter and receiver pairs to a particular host transmit frequency and host receive frequency corresponding to a particular first FM communication channel, and selectably tuning the PNI receiver and PNI transmitter in each PNI to a particular host transmit frequency and host receive frequency corresponding to a particular first FM communication channel.

38. A method as recited in claim 37, further including the steps of: communicating the digital information over each first FM communication channel through an alternating serial stream of control bytes and data packets, one or more control bytes comprising a control word, the control words being communicated at any one period of time over any of the first FM communication channels being identical; interpreting the control words within each PNI; and tuning each PNI to a particular first FM communication channel according to the interpreted control words.

39. A method as recited in claim 36, wherein FSK modulation is employed by the host device and the plurality of PNIs.

40. A method as recited in claim 36, further including the step of transmitting and receiving digital information over a twisted pair telephone line.

41. A method as recited in claim 40, each first FM communication channel having a unique host transmit frequency and host receive frequency occurring outside a frequency range occupied by POTS, ADSL, or HomePNA.

42. A method as recited in claim 40, the host transmit and host receive frequencies of the plurality of first FM communication channels occurring in a frequency range between about 1 MHz to about 5 MHz.

43. A method as recited in claim 40: the host receive frequencies of the plurality of first FM communication channels occurring in a frequency range between about 2 MHz to about 2.6 MHz; and the host transmit frequencies of the plurality of first FM communication channels occurring in a frequency range between about 3.3 MHz to about 3.9 MHz.

44. A method as recited in claim 36, further including the steps of: locking a plurality of host receiver PLL VCOs to the host reference source for generating a plurality of host local oscillator frequencies; demodulating the plurality of PNI transmit signals using the plurality of host local oscillator frequencies; locking a plurality of host transmitter PLL VCOs to the host reference source for generating the plurality of host transmit frequencies; and modulating the plurality of host transmit frequencies with digital information to be transmitted over the shared communication link, the plurality of modulated host transmit frequencies comprising the plurality of host transmit signals.

45. A method as recited in claim 44, wherein the digital information is added to a correction voltage of the host transmitter PLL VCO to modulate the host transmit frequency.

46. A method as recited in claim 44, wherein the digital information modifies a feedback divider in the host transmitter PLL VCO to modulate the host transmit frequency.

47. A method as recited in claim 44, the plurality of first FM communication channels comprising four first FM communication channels; wherein the host reference source is 32 MHz, the host receive frequencies of the four first FM communication channels are 2 MHz, 2.2 MHz, 2.4 MHz, and 2.6 MHz, the host transmit frequencies of the four first FM communication channels are 3.3 MHz, 3.5 MHz, 3.7 MHz, and 3.9 MHz, and the host local oscillator frequencies of the four receive PLL VCOs are 12.7 MHz, 12.9 MHz, 13.1 MHz, and 13.3 MHz.

48. A method as recited in claim 44, wherein for each PNI, the method further includes the steps of: locking a PNI receiver PLL VCO to a PNI reference source for generating a PNI local oscillator frequency; demodulating a host transmit signal using the PNI local oscillator frequency; locking a PNI transmitter PLL VCO to the PNI reference source for generating a host receive frequency; and modulating the host receive frequency with digital information to be transmitted over the shared communication link, the modulated host receive frequency comprising the PNI transmit signal.

49. A method as recited in claim 48, wherein the digital information is added to a correction voltage of the PNI transmitter PLL VCO to modulate the host receive frequency.

50. A method as recited in claim 49, wherein the digital information modifies a feedback divider in the PNI transmitter PLL VCO to modulate the host receive frequency.

51. A method as recited in claim 48, the plurality of first FM communication channels comprising four first FM communication channels; wherein the PNI reference source is 32 MHz, the host receive frequencies of the four first FM communication channels are 2 MHz, 2.2 MHz, 2.4 MHz, and 2.6 MHz, the host transmit frequencies of the four first FM communication channels are 3.3 MHz, 3.5 MHz, 3.7 MHz, and 3.9 MHz, and the PNI local oscillator frequencies of the four receive PLL VCOs are 14 MHz, 14.2 MHz, 14.4 MHz, and 14.6 MHz.

52. A method as recited in claim 36, wherein the shared communication link is AC power wiring transformer-coupled to the host device.

53. A method as recited in claim 52, each first FM communication channel having a unique host transmit frequency and host receive frequency occurring outside a frequency range occupied by CEBus or X-10.

54. A system as recited in claim 52, the host transmit and host receive frequencies of the plurality of first FM communication channels occurring in a frequency range between about 25 kHz to about 250 kHz.

55. A method as recited in claim 36, further including the step of transmitting and receiving digital information over an external communication link through a plurality of second communication channels using the host device.

56. A method as recited in claim 55, wherein the external communication link is a twisted pair telephone line.

57. A method as recited in claim 55, wherein the digital information transmitted and received over the external communication link is communicated according to DSL or voDSL protocols.

58. A method as recited in claim 55, wherein the external communication link is a coaxial cable.

59. A method as recited in claim 55, wherein the external communication link is a wireless communication link.

60. A method as recited in claim 57, further including the steps of: converting incoming DSL data received over the external communication link to incoming ATM data; separating out incoming voice data from the incoming ATM data, and communicating the incoming voice data to the plurality of host transmitters for transmission over the internal communication link; and receiving outgoing voice data to be transmitted over the external communication link from the plurality of host receivers, converting the outgoing voice data to outgoing ATM data, converting the outgoing ATM data to outgoing DSL data, and communicating the outgoing DSL data over the external communication link.

61. A method as recited in claim 60, further including the steps of: separating out incoming Internet/network data from the incoming ATM data, and communicating the incoming Internet/network data to PCs coupled to the internal communication link, an Ethernet LAN, or an RS-232 connector; and receiving outgoing Internet/network data from the PCs coupled to the internal communication link, an Ethernet LAN, or an RS-232 connector, converting the outgoing Internet/network data to outgoing ATM data, converting the outgoing ATM data to outgoing DSL data, and communicating the outgoing DSL data over the external communication link.

62. A method as recited in claim 60, further including the steps of: separating out incoming AC power line control data from the incoming ATM data, and communicating the incoming AC power line control data to devices coupled to an AC power line; and receiving outgoing AC power line control data from the devices coupled to the AC power line, converting the outgoing AC power line control data to outgoing

ATM data, converting the outgoing ATM data to outgoing DSL data, and communicating the outgoing DSL data over the external communication link.