Apparatus and method of coupling home network signals between an analog phone line and a digital bus

• US 6,836,546 B1
• Filed: 02/01/2000
• Issued: 12/28/2004
• Est. Priority Date: 11/03/1999
• Status: Expired due to Fees

• Current Assignee: GlobalFoundries, Inc.
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Willer, Bernd
• Primary Examiner(s): Tieu, Binh
• Assistant Examiner(s): Pham, Tuan
• Application Number:
  US09/495,122
• Time in Patent Office: 1,792 Days
• Field of Search: 379/387.01, 379/390.02, 379/392.01, 379/399.01, 379/413.02, 379/413.03, 375/76, 370/201, 370/271, 370/493, 370/521, 370/524
• US Class Current: 379/399.01
• CPC Class Codes: H04M 3/005 Interface circuits for subscriber lines current supply H04M19/00 and subgroups; supervisory, monitoring or testing arrangements H04M3/22 and subgroups; in key telephone systems H04M9/006

Abstract

An arrangement for implementing a network in an ISDN-based customer premises having a four-wire ISDN S0 bus. The ISDN-based customer premises includes a Network Termination Basic Access (NTBA) that interfaces between the residential customer premises and the public switched telephone network by mapping the two-wire ISDN signal onto the four-wire bus. A low pass filter is added to the two-wire send path to eliminate high frequency noise caused by harmonic reflections of the ISDN-based signals on the four-wire bus. Filters are also coupled between each ISDN device and the four-wire S0 bus, ensuring that the four-wire S0 bus is isolated from capacitive influences of the ISDN devices to optimize transmission of the higher frequency home network signals. The two-wire home network signals are also split by S0 transformers for transmission on the two-wire send path and the two-wire receive path of the four-wire S0 bus, effectively increasing the transmission wire radius for improved reception of the home network signals. A high pass filter is coupled between the four-wire S0 bus and analog telephone lines, enabling network stations coupled to the analog telephone lines to exchange home network signals with network stations coupled to the four-wire bus.

Claims

1. A method of implementing a local area network in a home telephone network having a connector, configured for sending and receiving ISDN-based signals to and from a public switched telephone network, and a four-wire bus including a two-wire send path and a two-wire receive path for sending and receiving the ISDN-based, signals, respectively, between the connector and connected ISDN terminal devices, the method comprising:

connecting a high pass filter between the four-wire bus and a two-wire analog telephone line configured for transmitting analog telephone signals; and

transmitting network data signals between a first network node coupled to the four wire bus and a second network node coupled to the two-wire analog telephone line.

2. The method of claim 1, further comprising isolating capacitive influences of each of the connected terminal devices from the two-wire send path by adding a common mode choke between each corresponding ISDN terminal device and the two-wire send path.

3. The method of claim 2, wherein the transmitting step includes:

coupling a first home network signal to a middle tap of a primary winding of a first S0 transformer coupled to the two-wire send path; and

coupling a second home network signal to the middle tap of the primary winding of a second S0 transformer coupled to the two-wire receive path.

4. The method of claim 3, further comprising receiving by the second network node the first and second home network signals, comprising:

receiving the first home network signal from the middle tap of the primary winding of a third S0 transformer coupled to the two-wire send path;

receiving the second home network signal from the middle tap of the primary winding of a fourth S0 transformer coupled to the two-wire receive path; and

passing the first and second home network signals through the high pass filter to the second network node via the two-wire telephone line.

5. The method of claim 4, wherein the transmitting step includes transmitting the first and second home network signals to the second network node across a distance of about 80 meters.

6. The method of claim 1, wherein the transmitting step includes:

coupling a first home network signal to a middle tap of a primary winding of a first S0 transformer coupled to the two-wire send path; and

coupling a second home network signal to the middle tap of the primary winding of a second S0 transformer coupled to the two-wire receive path.

7. The method of claim 6, further comprising receiving by the second network node the first and second home network signals, comprising:

receiving the first home network signal from the middle tap of the primary winding of a third S0 transformer coupled to the two-wire send path; and

receiving the second home network signal from the middle tap of the primary winding of a fourth S0 transformer coupled to the two-wire receive path; and

passing the first and second home network signals through the high pass filter to the second network node via the two-wire telephone line.

8. A computer network comprising:

a connector configured for sending and receiving ISDN-based signals to and from a public switched telephone network;

a four-wire bus having a two-wire send path and a two-wire receive path for sending and receiving the ISDN-based signals between the connector and ISDN terminal devices;

a low pass filter, coupled between the two-wire send path and the connector, for isolating capacitive influences of the connector from the two-wire send path and filtering ISDN harmonic signals occurring substantially at the frequencies of network data signals;

ISDN terminal filters, each configured for isolating capacitive influences of a corresponding one of the ISDN terminal devices from the two-wire send path;

first and second end stations configured for exchanging the network data signals at frequencies substantially higher than the ISDN-based signals via at least one of the two-wire send path and the two-wire receive path, the first end station coupled to at least one of the two-wire send path and the two-wire receive path and the second end station coupled to an analog telephone line; and

a high pass filter for coupling the four-wire bus to the analog telephone line, the second end station exchanging the network data signals via the analog telephone line and the four-wire bus.

9. The computer network of claim 8, further comprising first and second S0 transformers configured for coupling the first end station to the two-wire send path and the two-wire receive path, respectively, each of the first and second S0 transformers having a primary winding coupled to the corresponding two-wire path, each primary winding having a middle tap path configured for coupling to a corresponding network data signal differential input of the first end station.

10. The computer network of claim 9, further comprising third and fourth S0 transformers configured for coupling the high pass filter to the two-wire send path and the two-wire receive path, respectively, each of the third and fourth S0 transformers having the primary winding coupled to the corresponding two-wire path and having the middle tap path configured for coupling to a corresponding terminal end of the high pass filter.

11. The computer network of claim 10, wherein the first and second end stations exchanging the network data signals across the two-wire send path and the two-wire receive path have a transmission distance of about 80 meters.

12. The computer network of claim 8, wherein the four-wire bus is an internal S0 bus of a private branch exchange.