IL113591A - Telecommunication repeater - Google Patents

Description

rr3i3"?u rniuipn ττιπ TELECOMMUNICATION REPEATER ECI TELECOM LTD.

C.20655 20655eci.re2 HB-9505 2/5/95 FIELD OF THE INVENTION The present invention relates to telephony in general and more particularly to access network equipment.

BACKGROUND OF THE INVENTION Various systems are known for providing telecommunication services to multiple subscribers over a single twisted pair of copper wires. Where access networks extend beyond a predetermined distance from a local exchange, repeaters are required both for regeneration of signals on the network and for providing energy required by subscriber units.

SUMMARY OF THE INVENTION The present invention seeks to provide an improved repeater which has a greater range than conventional telecommunications repeaters .

There is thus provided in accordance with a preferred embodiment of the present invention a telecommunications repeater including: at least first and second input ports receiving DC electrical power from a local exchange along at least first and second pairs of copper wires; at least one output port providing DC electrical power to remote subscriber equipment via at least a third pair of copper wires; an electrical interconnection between the first input port and the at least one output port for supplying the DC power directly from the first input port to the at least one output port; and a DC to DC converter fed by DC power from the second input port and providing additional DC power to the at least one output port, thereby to increase the DC voltage transmitted along the third pair of copper wires.

There is also provided in accordance with a preferred embodiment of the present invention an access network telecommunications system including: interface circuitry coupled to a telephone exchange; a plurality of pairs of copper wires coupled to the interface circuitry; remote subscriber equipment; and a telecommunications repeater including: at least first and second input ports receiving DC electrical power from the exchange along at least first and second pairs of the plurality of copper wires; at least one output port providing DC electrical power to the remote subscriber equipment via at least a third pair of copper wires; an electrical interconnection between the first input port and the at least one output port for supplying the DC power directly from the first input port to the at least one output port; and a DC to DC converter fed by DC power from the second input port and providing additional DC power to the at least one output port, thereby to increase the DC voltage transmitted along the third pair of copper wires.

Preferably, the at least first and second input ports include first and second input ports.

In accordance with a preferred embodiment of the present invention the at least one output port includes a single output port.

Preferably, the DC to DC converter includes an optocoupler.

In accordance with a preferred embodiment of the present invention, at least one of the first and second pairs of copper wires carries digital information signals.

" BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be understood and appreciated from the following detailed description, taken in conjunction with the drawings in which: Fig. 1 is a simplified illustration of a telecommunications access network system constructed and operative in accordance with a preferred embodiment of the present invention; Fig. 2 is a simplified illustration of part of the apparatus of Fig. 1; Fig. 3 is a detailed illustration of part of the apparatus of Fig. 2; Figs. 4A and 4B are detailed illustrations of another part of the apparatus of Fig. 2; Fig. 5 is a detailed illustration of yet another part of the apparatus of Fig. 2; and Figs. 6A and 6B are detailed illustrations of still another part of the apparatus of Fig. 2.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Reference is now made to Fig. 1, which is a simplified block diagram illustration of a telecommunications access network system constructed and operative in accordance with a preferred embodiment of the present invention. The system of Fig. 1 typically includes a conventional telephone exchange 10, to which are connected a multiplicity of exchange units 12.

The exchange units 12 are each operative to convert a multiplicity of telephone signals arriving from the telephone exchange 10 into a digital bitstream. This digital bit stream, which contains the digitally encoded telephone signals and corresponding signaling, is converted in the exchange unit 12 to a telecommunications signal, such as the 2B1Q line code as specified for standard transmission of Basic Rate ISDN or the HDSL - High bit rate Digital Subscriber Line.

Each exchange unit 12 provides two outputs of two respective twisted pairs of copper wires 14 and 16. The first twisted pair 14 typically carries a telecommunications signal as well as a DC voltage, while the second twisted pair 16 typically carries only a DC voltage.

In accordance with a preferred embodiment of the present invention, a repeater 20 is provided which receives two inputs over the respective twisted pairs 14 and 16 and provides an output along a third twisted pair of copper wires 22 to a remote unit 24. This third twisted pair of copper wires 22 preferably carries a telecommunications signal as well as a DC voltage.

The telecommunications signal produced by the exchange unit 12 comprises two signals: A first signal is transmitted from the exchange unit 12 to the remote unit 24 via repeater 20. A second signal is transmitted on the same line in the opposite direction using the echo cancellation technique as described in CCITT Recommendation 1-431.

It is a particular feature of the present invention that the repeater 20 includes at least first input port 30 and second input port 32 receiving DC electrical power from a local exchange unit 12 along at least first pair of copper wires 14 and second pair of copper wires 16, at least one output port 54 providing DC electrical power to remote subscriber equipment via at least a third pair of copper wires 22, an electrical interconnection between the first input port 50 and the at least one output port 54 for supplying the DC power directly from the first input port 50 to the at least one output port 54 and a DC to DC converter fed by DC power from the second input port 52 and providing additional DC power to the at least one output port, thereby to increase the DC voltage transmitted along the third pair of copper wires 22.

Remote unit 24, coupled to each twisted pair 22, is in turn connected to a number of telecommunications subscribers 26. The remote unit receives the telecommunications signals and converts them back to a multiplicity of telephone signals which are interfaced with ordinary telephone sets 26.

Reference is now made to Fig. 2 is a simplified illustration of part of the apparatus of Fig. 1. Fig. 2 provides a more detailed illustration of the repeater unit 20. It is seen that the telecommunications signals and DC voltages received over twisted pairs 14 from exchange unit 12 are received at a splitter 28, which is operative to strip off the DC and direct it to a repeater power supply unit 30, which also receives a separate DC input from exchange unit 12 over twisted pair 16.

The telecommunications signals are supplied to a telecom signal repeater 32, which receives power from the repeater power supply unit 30 and provides an amplified telecommunications signal output to a combiner 34, which receives a DC input from repeater power supply unit 30 and provides a combined DC voltage and telecommunications signal via twisted pair 22 to remote unit 24.

Reference is now made to Fig. 3, which is a detailed illustration of the repeater power supply unit 30, forming part of the apparatus of Fig. 2. The repeater power supply unit 30 comprises a rectifier bridge 40 which receives a DC voltage from splitter 28 and is coupled to a main switching power supply 60 including a FET 42, a transformer 44, a switching power supply control and drive circuit 46, and a local voltages regulator 48.

The local voltages regulator 19 provides a control output via an optocoupler transmitter 50 to switching power supply control and drive circuitry 46, via an optocoupler receiver 52 associated therewith.

A complementary power supply regulator 54 is associated with the main switching power supply 60 and receives a DC input from a rectifier bridge 56, which in turn receives DC voltage via twisted pair 16 from the exchange unit 12.

Complementary power supply regulator 54 is operative to provide a DC voltage output to combiner 34 (Fig. 2). Regulator 54 combines the voltages received via twisted pairs 14 and 16 to provide the necessary voltage required along twisted pair 22.

Figs. 4A and 4B together form a partial electrical schematic of part of the circuitry of Fig. 3 including inter alia rectifier bridge 40, switching power supply control and drive circuitry 46, and part of transformer 44. The electrical schematic is believed to be self-explanatory and therefore, for the sake of conciseness, no additional description is provided herein.

Fig. 5 is a partial electrical schematic of another part of the circuitry of Fig. 3 including inter alia local voltages regulator 48 and part of transformer 44. The electrical schematic is believed to be self-explanatory and therefore, for the sake of conciseness, no additional description is provided herein.

Figs. 6A and 6B together form a partial electrical schematic of part of the circuitry of Fig. 3 including inter alia complementary power supply regulator 54 and part of transformer 44. The electrical schematic is believed to be self-explanatory and therefore, for the sake of conciseness, no additional description is provided herein.

It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the invention is defined only by the claims which follow:

Claims (8)

C L A I M S

1. A telecommunications repeater comprising: at least first and second input ports receiving DC electrical power from a local exchange along at least first and second pairs of copper wires; at least one output port providing DC electrical power to remote subscriber equipment via at least a third pair of copper wires; an electrical interconnection between said first input port and said at least one output port for supplying said DC power directly from said first input port to said at least one output port; and a DC to DC converter fed by DC power from said second input port and providing additional DC power to said at least one output port, thereby to increase the DC voltage transmitted along said third pair of copper wires.

2. An access network telecommunications system comprising: interface circuitry coupled to a telephone exchange; a plurality of pairs of copper wires coupled to said interface circuitry; remote subscriber equipment; and a telecommunications repeater comprising: at least first and second input ports receiving DC electrical power from said exchange along at least first and second pairs of said plurality of copper wires; at least one output port providing DC electrical power to said remote subscriber equipment via at least a third pair of copper wires; an electrical interconnection between said first input port and said at least one output port for supplying said DC power directly from said first input port to said at least one output port; and a DC to DC converter fed by DC power from said second input port and providing additional DC power to said at least one output port, thereby to increase the DC voltage transmitted along said third pair of copper wires.

3. Apparatus according to either of the preceding claims and wherein said at least first and second input ports comprise first and second input ports.

4. Apparatus according to any of the preceding claims and wherein said at least one output port comprises a single output port.

5. Apparatus according to any of the preceding claims and wherein said DC to DC converter comprises an optocoupler.

6. Apparatus according to any of the preceding claims and wherein at least one of said first and second pairs of copper wires carries digital information signals.

7. Apparatus according to any of the preceding claims, substantially as shown and described hereinabove.

8. Apparatus according to any of the preceding claims, substantially as illustrated in any of the drawings. For the Applicants, Sanford T. Colb & Co. Advocates & Patent Attorneys C: 20655 HB-9505