KR20000067240A - Method for managing power in asymmetrical data transmitting apparatus using adsl - Google Patents

Abstract

PURPOSE: A method for managing a power in an asymmetric data transmission apparatus using an asymmetric subscriber line is provided to decrease an average consumption power of an ADSL(Asymmetric Digital Subscriber Line) by not providing the power to a corresponding block of the ADSL in which its operation is unnecessary in a sleep state. CONSTITUTION: If a sleep state is requested in a normal operation mode, a sleep mode state is performed. A transmitting block of an ADSL modem related to a pilot tone transmission for maintaining a loop and a receiving block of the ADSL modem related to a receipt of a normal operation mode return signal are enabled, and other blocks are disabled. If a normal operation mode return request is received in the sleep mode, and all blocks of the ADSL modem are enabled to return the normal operation mode state.

Description

Power management method in asymmetric data transmission apparatus using asymmetric subscriber line {METHOD FOR MANAGING POWER IN ASYMMETRICAL DATA TRANSMITTING APPARATUS USING ADSL}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission apparatus for connecting a high speed data network to a subscriber line at the request of a subscriber. In particular, the present invention relates to asymmetric data transmission using an asymmetric digital subscriber line (hereinafter referred to as "ADSL"). A method for power management in an apparatus.

ADSL is a transmission technology that enables high speed downstream transmission and low speed upstream transmission using a frequency band higher than a voice signal frequency band by using a conventional telephone subscriber line. Downlink transmission means transmission from the network to the subscriber, and uplink transmission means transmission from the subscriber to the network.

The asymmetric data transmission apparatus using the ADSL connects a high-speed data network to a telephone subscriber line according to a subscriber's request. Accordingly, subscribers can receive services such as video on demand and the Internet through subscriber lines.

The above-mentioned asymmetric data transmission apparatus is typically an asymmetric data local station (hereinafter abbreviated as "local station") connected to each subscriber line one by one, and an asymmetric data mother station (hereinafter referred to as "master station device") connected between a high speed data network and a subscriber line. Abbreviated as ". Such a mother station device and a local station communicate using a frequency band higher than a voice signal frequency band. The mother station apparatus includes a subscriber modem unit for modulating and demodulating signals transmitted between the high speed data network and the local station apparatus, and one subscriber modem unit is fixedly allocated and used for each subscriber line. In addition, the subscriber modem unit separates the voice signal and the analog signal of the corresponding subscriber line so that the voice signal is transmitted to the telephone exchange side, and the analog signal is provided with a voice signal splitter which cuts off the telephone exchange side. The voice signal is a signal for a telephone call, and the analog signal is a data signal transmitted with a high speed data network.

On the other hand, ADSL modem or U-ADSL (Universal-ADSL) modem can always use existing voice-band apprication, such as telephone / fax, on the same telephone line (hereinafter called "ALWAYS-ON" mode). Can be operated. Thus, subscribers are as if they are using a local area network (LAN) at home. In this case, the service fee is a monthly subscription, so depending on the subscriber, the modem may be turned on throughout the month. However, the existing modem is not considered for the separate power management, so the user has to turn off and on the modem from time to time.

Accordingly, an object of the present invention is to provide a power management method for reducing the average power consumption of the ADSL digital modem.

In accordance with the above object, the present invention provides a power management method in an asymmetric data transmission apparatus using an asymmetric subscriber line and transmitting data using a discrete multitone modulation and demodulation scheme, wherein a sleep request signal is received in a normal operation mode. Asymmetrical subscriber line associated with the process of proceeding to the sleep mode and receiving the normal operation mode return signal for requesting to return to the normal operation mode and the transmission block of the asymmetric subscriber line modem related to pilot tone transmission for loop maintenance in the sleep mode state. Enabling each receiving block of the modem and disabling the remaining blocks; and upon receiving the normal operation mode return signal, enable all blocks of the modem on the asymmetrical subscriber line and return to the normal operation mode. Characterized in that made.

1 is a view showing an ADSL network configuration,

2 is a functional block diagram of an ADSL modem;

3 is a detailed block diagram of an ADSL modem for better understanding of power management according to an embodiment of the present invention;

4 is a mode transition state diagram in the U-ADSL modem for explaining an embodiment of the present invention;

5 is a diagram illustrating a pilot tone state of each signal;

6 is a conceptual control flowchart of a power management method of an ADSL modem according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that like elements and like parts in the figures are denoted by the same reference numerals or the same reference numerals wherever possible. In addition, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

1 is a diagram showing an ADSL network configuration, Figure 2 is a functional block diagram of an ADSL modem.

First, referring to FIG. 1, the ADSL modem 2 of the mother station apparatus is connected to the broadband data network 6, and the ADSL modem 4 of the local station apparatus is connected to the subscriber station 8. Since ADSL does not use the frequency band used in the existing telephone network, it can be used simultaneously with the telephone. For this purpose, as shown in FIG. 1, the ADSL modems 2 and 4 on the mother station side and the local station side have ports. The separator 10 and 12 are included. The PSTN telephone network 14 is connected to the other end of the port separator 10 of the mother station apparatus side, and the port telephone 16 is connected to the port separator 12 of the local station side. The port separators 10 and 12 separate a frequency band used by the telephone network. The ADSL modems 2 and 4 of the mother station and the slave station are connected by twisted pair telephone lines 18.

FIG. 2 schematically shows the functional blocks of the ADSL modems 2 and 4 on the mother station apparatus and the host apparatus side shown in FIG. The ADSL modem shown in FIG. 2 is an ADSL modem 4 on the local device side, and includes a port separator 12, a block 20 including a D / A, A / D converter, a concentrator, and a channel separator, and a transmitter 22. , A receiver 24, a multiplexer 26, and a demultiplexer 28. It should be understood that the host station side ADSL modem 2 has a symmetrical structure with the ADSL modem 4 of the host station side.

Meanwhile, as the use of the Internet is becoming more common, the demand for high-speed modems is increasing. The U-ADSL digital modem is a modem capable of high-speed data transmission of up to 1.5Mbps (about 27 times that of an existing analog modem) by using frequency-dividing Discrete MultiTone (DMT) modulation and demodulation technology. The standardized DMT method uses 256 tones each of which is 4.3125 kHz wide downstream. United States Patent No. 5,673,290 (ADSL COMPATIBLE DISCRETE MUTITONE APPARATUS), invented by inventor John Cioffi and issued on September 30, 1997, discloses a DMT transmission technique.

When connecting to the Internet using a U-ADSL digital modem, a sleep state may occur frequently in which no data comes in for a certain period of time between data transmission and reception. Therefore, the U-ADSL standard specifies sleep mode as an option. In this sleep mode, data transmission is interrupted and loop timing is maintained from the home station (telephone station) ADSL modem to the local station (subscriber) ADSL modem. Only pilot tones are transmitted.

In the embodiment of the present invention, it is intended to minimize the average power consumption of the system by making the most of the optional sleep state as described above. Especially in portable devices such as notebook PCs (Personal Computors), low power design is a must.

3 is a detailed block diagram of an ADSL modem for better understanding of power management according to an embodiment of the present invention.

Referring to FIG. 3, the transmitter 30 of the ADSL modem configuration includes a QAM encoder (Quadrature Amplitude Modulation encoder) 32, a tone generator 34, a multiplexer 36, an IFFT (Inverse Fast Fourier Transformer) 38, and a PAR. It includes a reduction unit (Peak to Average power Ratio reduction) 40, an interpolation filter (42), a digital to analog converter (DAC) 44, and a band pass filter (BPF) 46. The receiver 50 includes a BPF 52, an analog to digital converter (ADC) 54, a decimation filter 56, a time domain EQualizer 58, a fast fourier transform 60, and an FEQ. (Frequency domain EQualizer; 62), and a QAM decoder 64.

4 is a mode transition state diagram in a U-ADSL modem for explaining an embodiment of the present invention, a full-on mode state, a fast-retrain mode state, and a sleep mode. It is divided into states.

5 is a diagram illustrating a pilot tone state of each signal. In FIG. 5, the number on the x-axis indicates the number of times the pilot tone corresponding to the corresponding signal is present in the DMT. The C-SLEEP signal is a signal transmitted from the master station to the own station to bring the local station into sleep mode. The C-RECOV signal is used to return the local station in the sleep mode to the normal operation mode. Signal transmitted from the device to the local station. And the R-SLEEP signal is a signal transmitted from the local station to the mother station device to enter the sleep mode state, and the R-RECOV signal is used to return the mother station device in the sleep mode state to the normal operation mode state. Signal transmitted from the local station to the mother station.

Hereinafter, an operation according to an embodiment of the present invention will be described in detail with reference to FIGS. 3 to 5.

As shown in FIG. 4, when the C-SLEEP signal is transmitted from the mother station apparatus or the R-SLEEP signal is transmitted from the local station apparatus in the normal operation mode (FULL-ON), the local station apparatus receives the C-SLEEP signal. The ADSL modem on the mother station side receiving the ADSL modem or the R-SLEEP signal of the modem enters the sleep mode. In sleep mode, only the pilot timing is transmitted from the ADSL modem on the host station side to the own station to maintain only the loop timing. When the wake-up R-RECOV / C-RECOV signal is received in the sleep state, the mother station or the local station returns to the normal operation mode within 1 second through the fast retrain mode. Goes.

In the sleep mode, the tone of the C-SLEEP signal (ie, the 64th pilot tone (276KHz)) and the tone of the R-RECOV / C-RECOV signal (ie, the C-RECOV signal) as shown in FIG. Since the 64th and 68th pilot tones and the R-RECOV signal only need to transmit and receive the 20th and 64th pilot tones), the ADSL modem does not need to oversample the transmitted and received signals. Therefore, partial disabling of related blocks that do not require operation in the ADSL modem configuration enables operation in a low power mode.

A conceptual control flowchart of a power management method of an ADSL modem according to an embodiment of the present invention is shown in FIG. 6. Referring to FIG. 6, when the sleep request signal is received in the normal operation mode state (step 100) (step 102), the process proceeds to the sleep mode state (step 104). In the sleep mode, as shown in step 106, the ADSL modem transmission block associated with pilot tone transmission for loop maintenance and the ADSL modem reception block related to reception of the normal operation mode return signal for the normal operation mode return request are enabled. Place and disable the remaining blocks. When a request for returning to the normal operation mode in the sleep mode is maintained (step 108), all blocks of the ADSL modem are enabled, and the operation returns to the normal operation mode (step 100).

According to the embodiment of the present invention in the sleep mode described above, in the ADSL modem of the mother station, the remaining blocks excluding the parts related to pilot tone transmission and R-RECOV signal reception, that is, the QAM encoder 32 in FIG. The PAR reduction unit 40 and the interpolation filter 42 are disabled. The decimation filter 56, the TEQ 58, the FEQ 62, and the QAM decoder 64 are decoded in all the blocks except for the portion related to the reception of the C-RECOV signal in the ADSL modem of the local station. Enable it.

This will be described in more detail as follows. If there is no data transmitted or received on the channel for a certain period of time, the host controller on the host station side issues a sleep command to the ADSL modem. Accordingly, the tone generator 34 in the ADSL modem of the mother station generates a C-SLEEP signal as shown in FIG. Since the C-SLEEP signal is a tone signal of 276KHz, the PAR reduction in the PAR reduction unit 40 is not necessary, and the tone of the C-SLEEP signal in the ADSL modem of the local station is not oversampled using the interpolation filter 42. Can be detected. This fact was verified by the inventor's experiment. Therefore, in the sleep mode, the QAM encoder 32, the PAR reduction unit 40, and the interpolation filter 42 in the ADSL modem of the master station are disabled to reduce power consumption in the ADSL modem.

On the other hand, in the sleep mode, the receiving unit 50 of the local station side and the main station side ADSL modems only need to detect the C-RECOV / R-RECOV signal, thus eliminating the need for the decimation filter 56 and being a repetitive tone signal. TEQ 58 is also not used to reduce interference. Therefore, in the sleep mode, the decimation filter 56 and the TEQ 58 in the ADSL modem of the mother station and the local station are disabled to reduce power consumption in the ADSL modem.

The embodiment of the present invention performs power management not only in the sleep mode state but also in the idle state, the C-T0NE state, and the R-ACT-REQ state.

First, in the idle state, both the transmitting and receiving ends are turned off and only the command of the host controller is waiting. Therefore, both the transmitting clock and the receiving clock are turned off. The C-TONE state indicates that the ATU-C is not ready to communicate. At this time, only the transmitter clock is turned on and the receiver clock is turned off. The R-ACT-REQ state indicates that the ATU-R is ready to communicate with the ATU-C request. At this time, the transmitter clock is turned off and only the receiver clock is turned on. In C-QUIET1 / R-QUIET1, the clock of the transmitter is turned off.

The idle state, the C-TONE state, and the R-ACT-REQ state are prescribed by American National Standard Institute (TAN) T.4133.

In the above description of the present invention, specific embodiments have been described, but various modifications can be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be defined by the equivalent of claims and claims.

As described above, since the present invention does not supply power to the corresponding block in the ADSL modem, which is not necessary in the sleep state, the average power consumption of the ADSL digital modem can be reduced.

Claims (1)

A power management method in an asymmetric data transmission apparatus using asymmetric subscriber line and transmitting data using a discrete multitone modulation and demodulation scheme, When the sleep request signal is received in the normal operation mode, the process proceeds to the sleep mode; In the sleep mode, enable a transmission block of an asymmetric subscriber line modem related to pilot tone transmission for loop maintenance and a reception block of an asymmetric subscriber line modem related to receiving a normal operation mode return signal for requesting to return to normal operation mode. And rest of the rest of the blocks, And when the normal operation mode return signal is received, enabling all blocks of the asymmetric subscriber line modem and returning to the normal operation mode state.