KR20010057403A - ADSL modem using of USB port - Google Patents

Abstract

PURPOSE: An ADSL(Asymmetric Digital Subscriber Bus) modem using a UBS(Universal Serial Bus) port is provided to directly connect a PC which supports a USB port without installing an additional card in a PC using a USB port for a portion to which an ADSL mode physical hierarchy is connected. CONSTITUTION: A USB(Universal Serial Bus) support controller(40) supports a USB and a controller supported by a UTOPIA(Universal Test and Operation Physical for ATM) interface. A bootable flash and DRAM are provided in a memory block(50) of a controller(40) or thereby downloading a program at an initial stage and processing the data. The ADSL system DSP(35) controls the functions that an address and data pass between the ADSL chip sets in an interface and framer(34), an analog front end(32) and a coder DMT(Discrete Multi-Tone) processor(33) based on the connection of a control signal namely, read/write/reset signals. The analog front end(32) includes an ADSL chip set and digital and analog signals for thereby connecting the digital and analog signals. The interface and framer(33) perform an ADSL framing, FEC, interleave functions, and the core DMT signal processor supports a trellis coding/decoding in the transmission and receiving path and performs an IFFT/FFT. filtering and echo cancellation functions.

Description

ADSL modem using of USB port

The present invention relates to an Asymmetric Digital Subscriber Line (ADSL) modem using a Universal Serial Bus (hereinafter referred to as a USB) port, and in particular, a personal computer (hereinafter referred to as a PC). It is related to ADSL modem using USB port that allows USB port of) to be directly used in ADSL modem.

In general, ADSL system is a system that provides telephone service, video on demand (VOD) at the same time through the existing telephone line, the transmission rate of the downstream transmitted from the telephone company to the user from the user It is a system that realizes a higher speed than the upstream of upstream traffic to a telephone station, so that the downlink speed and the upstream speed are asymmetric.

Hereinafter, the general ADSL system will be described.

1 is a block diagram of a general ADSL system, in which the ADSL system 2 is connected to a broadband public network through an ATM switch 1, an International Signaling Point (ISP), a server, and the Internet. Send / receive bidirectional data. Thus, the ADSL system 2 is controlled and managed by the ADSL network management system to interface the bidirectional data of the broadband public network to the ATM switch 1.

The POTS splitter 3 multiplexes the data from the public switched telephone network (PSTN) and the data through the ATM switching network to the ADSL system 2. In addition, the data from the ADSL system 20 separates the data of the public payphone from the ADSL data.

Thus, the POTS separation unit 3 transmits the data of the general public telephone to the public telephone 4 from the transmitted data, and transmits the ADSL data and control signals to the PCs 6 and 8 through the external ADSL modems 5 and 7. To send.

Hereinafter, the ADSL modem according to the prior art will be described. 2 is a view showing the configuration of an ADSL modem according to the prior art.

As shown in FIG. 2, the ADSL modem includes a processor 11 for performing signal processing of the ADSL modem 5 to match the POTS separation unit 3 and the PC 6 shown in FIG. 1, and a POTS. Receives a DMT (Discrete Multi-Tone) modulated signal transmitted from the separation unit 3 and transmits it to the ATM cell conversion unit 13, and transmits the signal transmitted from the ATM cell conversion unit 13 to the POTS separation unit 3. DMT transmitter / receiver 12, ATM cell converter 13 for converting signals transmitted from DMT transmitter / receiver 12 into ATM cells, ATM cell converter 13 and ATM adaptation layer device ( 15) Signals between the UTOPIA interface unit 14 and the UTOPIA interface unit 14 and the ATM physical layer device 16, which interface between the UTOPIA (Universal Test and Operation Physical for ATM) method, are connected to each other by the SAR (Segmentation And Resembly) method. ATM adaptation layer device (15) and ATM cell transmitted from ATM adaptation layer device (15) are transmitted to PC (6) by physical transmission path. And it is configured to include a physical layer ATM device 16 for receiving ATM cells from the PC (6).

The PC 6 has an ATM communication interface card 21 that matches the ADSL modem 5 as described above.

The operation of the ADSL modem according to the prior art having such a configuration will be briefly described.

First, the DMT modulation signal is received from the POTS separation unit 3 at the DMT signal transmission / reception unit 12 and transmitted to the ATM cell conversion unit 13, and the ATM cell conversion unit 13 converts the DMT modulation signal into an ATM cell. Then, it interfaces with the UTOPIA method and transmits it to the ATM adaptation layer device 15. The ATM adaptive layer device 15 transmits the ATM cell to the ATM physical layer device 16 in a SAR manner, and the ATM physical layer device 16 transfers the ATM cell to the ATM 6 of the PC 6 as a physical transmission path. Transfer to the interface card 21. Thus, the PC 60 should be provided with an ATM communication interface card 21 for interfacing with the ADSL modem 5.

3 is a diagram illustrating an ADSL communication protocol stack for providing an ADSL service through a general buck ADSL modem.

First, the communication protocol of the ADSL network operator, that is, a telephone station equipped with an ADSL exchanger, is an Ethernet for communicating with the Internet using the Ethernet method, and TCP / IP (Trasport Control Protocol / Internetworking), which is a protocol for the network as the upper layer of the Ethernet. Protocol), LANE or PPP (Local Area Network Emulation or Point to Point Protocol), which is a communication protocol using a telephone line between a telephone company and an ADSL modem as a lower layer of TCP / IP, and AAL 5, an ATM network protocol, as a lower layer of LANE or PPP. And ASL 5 lower layer, which is composed of ADSL which is a protocol for ADSL service.

For ATM users, the ADSL modem and PC each contain the ATM 25 protocol for ATM communication between the ADSL modem and the user's PC. Therefore, PC through ATM communication should be equipped with ATM communication interface card to perform ATM 25 protocol.

In addition, for Ethernet users, the ADSL modem and the PC each include an Ethernet protocol for Ethernet communication between the ADSL modem and the user's PC. So a PC for Ethernet users should have a LAN card to run the Ethernet protocol.

As a result, the ADSL system according to the prior art mainly transmits ATM cells or frames based on the ATM physical layer and Ethernet. Based on ATM25, ADSL is a key technology to reduce the difference between ADSL transmission rate and ATM25 interface transmission.

In case of sending ATM cell, ATM card should be attached inside the PC. Existing ATM card is troublesome to install and occupy the inside of PC, and there is a problem that ATM card price is expensive.

In addition, Ethernet subscriber modem is more complicated than ATM25 model because it needs to perform protocol conversion function, and Ethernet processes packet through AAL 5 because it basically operates in Best Offset method.

Unlike the ATM25 model, the subscriber modem becomes the ATM service end point and communicates with the CPE through the Ethernet protocol. Ethernet cards are much cheaper than ATM cards, but they are also cumbersome to install and occupy a place inside the PC.

In the case of an ADSL modem, the internal serial communication controller must have an Ethernet or ATM interface. In this case, a separate Ethernet transceiver or ATM25 transceiver is required and the price is expensive.

Accordingly, the present invention has been made in order to solve the above problems according to the prior art, the object of the present invention is to use the USB port to the part connected to the ADSL modem physical layer without the need to enter the card in a separate PC USB port It provides an ADSL modem using a USB port so that it can be directly connected to a supported PC.

Another object of the present invention is to provide an inexpensive ADSL modem by implementing an ADSL modem without the need for an Ethernet card or an ATM card to be put in a separate PC using a simple USB transceiver.

ADSL modem using a USB port according to the present invention for achieving the above object is a USB transceiver that supports full speed 12Mbps using input and output digital data transmitted and received via a cable connected to a PC that supports the USB port ( In order to be able to physically process data using a transceiver, the controller supports up to 12Mbps USB and connects to a Master having 4 USB end points. Controllers that support both slaves are suitable. In Master mode, it can be used as ADSL's own loop back board to know if there is a problem with the modem. In Slave mode, the PC becomes a master to connect with the ADSL modem.

That is, the ADSL modem using the USB port according to the present invention is characterized in that in the ADSL system having a POTS, DMT signal processing means for receiving a DMT modulated signal transmitted through the POTS and converts the received DMT modulated signal into an ATM cell. and; Utopia interfacing means for interfacing the ATM cell converted by the DMT signal processing means in a utopia manner; USB support control means for converting the signal interfacing in the utopia interfacing means into data of a serial communication method, and then outputting the data through a USB bus; And a USB transmission means for transmitting a signal transmitted through the USB bus from the USB support control means to a USB port attached to the PC.

1 is a block diagram showing a general ADSL system;

2 is a view showing the configuration of an ADSL modem according to the prior art;

3 is a diagram illustrating a stack of an ADSL communication protocol for performing an ADSL service through a general ADSL modem;

4 is a view showing the configuration of an ADSL modem using a USB port according to the present invention.

FIG. 5 is a diagram illustrating a connection configuration of a management bus and a utopia bus shown in FIG. 4;

6 is a view showing in detail the connection configuration of the USB support controller and the USB transceiver shown in FIG.

<Explanation of symbols for main parts of drawing>

31: Driver / Receiver 32: Analog Front End

33 coder DMT signal processor 34 interface and framer

35: ADSL system DSP 40: USB support controller

50: memory block 60: USB transceiver

60: USB port 70: PC

Hereinafter, an ADSL modem using a USB port according to the present invention will be described in detail with reference to the accompanying drawings.

First, an important feature of the ADSL system is that it can provide high-speed digital services at the same time without interfering with analog telephone service on the existing twisted pair copper network. It is a technology that increases bandwidth so that multimedia information such as voice, traffic, and video can be simultaneously transmitted while using existing telephone lines, and has been in the spotlight as a service network that can deliver multimedia information to subscribers without incurring network installation costs. Thus, new services can be created that can be provided to telephone subscribers such as high speed internet, online access and telecommuting, and VOD. In addition, there is no need to install a new line, so it is possible to implement the service more economically and faster than using other systems.

4 is a diagram illustrating a configuration of an ADSL modem supported by USB according to the present invention.

In the present invention as shown in FIG. 4, the ADSL modem supporting USB should be connected to a PC 80 that supports USB externally, and an internal microprocessor supporting a USB serial communication controller should be used. Then, the USB transceiver 60 is a passage for data transmission and reception through all the USB port 70.

The USB support controller 40 is a controller in which USB is supported and a Utopia interface is supported.

In the memory block 50 around the controller 40, a flash flash and a DRAM are initially downloaded to process a data.

ADSL system DSP 35 is passed through the interface and framer 34, analog front end 32, and coder DMT processor 33, the address and data between the ADSL chipset, each control signal, that is, read / write / Reset (Read / Write / Reset) is connected to control.

Analog front end 32 has both the digital and analog of the ADSL chipset has the effect of connecting the digital and analog.

The interface and framer 33 perform ADSL framing, FEC, and interleaving functions, and the core DMT signal processor 33 supports Trellis coding / decoding in the transmission and reception paths. IFFT / FFT, filtering and echo cancellation are performed.

FIG. 5 is a diagram illustrating a connection configuration between a management bus and a utopia bus shown in FIG. 4.

When the ADSL chipset sends out RX and TX cell available signals, the USB support controller 40 sends out TX and RX enable signals. Data transfer begins at 40) by sending it to the ADSL chipset.

Meanwhile, in the case of RX, data transmission is started by sending a SOC (Start Of Cell) signal from the ADSL chipset to the USB support controller 40. At this time, data is transmitted and received in synchronization with the RX and TX clock signals sent from the USB support controller 40.

In the case of reception, before reassembly starts, the device driver 31 is used to reassemble ATM cell payloads from the USB support controller 40 to the CS-PDU. Memory Location, or buffers.

The starting address of each buffer used for reassembly must be stored as a free buffer queue in SRAM. All other data is initialized during the reassembly process. Next, the device driver enables the reception of the USB controller 40, and stores the ATM cell arriving on the Utopia bus of the USB controller 40 as the RX FIFO (First In First Out) of the SRAM. do. Here, the HEC bytes are removed and only 52 bytes are passed to the RX FIFO.

The USB support controller 40 loads a free buffer descriptor into a receive connection table.

The USB support controller 40 also fetches the free buffer descriptor from the free buffer queue, and then moves the buffer descriptor to the connection table. The free buffer descriptor points to the host memory location to reassemble the receive payload.

In addition, the USB support controller 40 is to transfer the 48-byte ATM cell payload to a specific free buffer location through the PCI bus master data transfer.

Then, in the case of transmission, the USB support controller 40 patches the cell payload from the waste memory when transmitting the cell. Once the cell payload is patched and formed into a complete ATM cell, it is stored in a Transmit Queue to provide a buffer for PCI latency. Once the CS-PDU is transmitted, the transmission status is generated.

The first step in the segmentation cycle is the device driver, which initializes the data structure.

Then, when the device driver turns on the transmitter and the transmitter is turned on, the USB support controller 40 starts the segmentation process while proceeding with the transmitter schedule table entry.

FIG. 6 is a detailed diagram illustrating a connection configuration of a USB support controller and a USB transceiver illustrated in FIG. 4.

When the USB support controller 40 gives a USBOE * signal, the USB transceiver 60 can transmit data on the bus. In a situation where the USBOE * is not activated, the USB transceiver 60 is in a state capable of receiving data. The USBSPEED signal is placed in full-speed mode to support up to 12Mbps in ADSL systems.

On the other hand, it was applied to ADSL broadband subscriber modem system but described and applied to any system that has one broadband access link such as VDSL and HDSL network access system as well as subscriber modem such as digital subscriber access equipment such as xDSL. With this possible technology, it is applied to a system that wants to configure a modem economically and simply and flexibly.

In addition, the modem for connecting to a PC having a USB port has an advantage that it can be easily implemented in any circuit if the USB support controller has a communication port supporting USB.

As described above, the ADSL modem using the USB port according to the present invention uses a USB port that is widely used in a modem that is commercially available as a structure considering the efficiency and economic efficiency of the system configuration as much as possible. Using the Utopia bus of the USB controller, the management bus of the ADSL chipset and the Utopia bus were interfaced with each other, and the function of interfacing with the USB transceiver was implemented using the USB bus of the USB controller.

In recent years, a PC with a USB port is easily available.If you use a cheap controller that supports Utopia mode and a USB interface, it is connected to the Utopia interface in the ADSL chipset, and a separate PC is used to transfer data to the PC through the USB port. The advantage is that there is no need for a card to go inside.

In addition, USB transceivers can be obtained at a much lower cost than ATM25-based or Ethernet-based ADSL, ie ATM25PHY and Ethernet transceivers that support Transmission Convergence (TC) and Physical Medium Dependent (PMD). There is no need for an ATM card or an Ethernet card to make it possible to configure an ADSL modem that is much simpler and cheaper.

In addition, there is an advantage that can be widely applied to the xDSL network subscriber modem card, such as AD, ADSL, VDSL, HDSL.

Claims (1)

In an ADSL system with POTS, DMT signal processing means for receiving a DMT modulated signal transmitted through the POTS and converting the received DMT modulated signal into an ATM cell; Utopia interfacing means for interfacing the ATM cell converted by the DMT signal processing means in a utopia manner; USB support control means for converting the signal interfacing in the utopia interfacing means into data of a serial communication method, and then outputting the data through a USB bus; And a USB transmission means for transmitting a signal transmitted through the USB bus from the USB support control means to a USB port attached to a PC.