KR950003716B1 - Terminal adapter of tip/ring and v-party interface - Google Patents

Abstract

The method gives the ISDN service by connecting the modem, G3, FAX, and PC to the ISDN terminal. The device includes a V-series signal converter (1) which converts the TTL signal to the V-interface signal, a speed matching unit (2) which receives the information from data line, a tip/ring terminating unit (3) which gives the tip/ring interface function, a codec and filter unit (4) which has the gain adjust function, a S-transceiver (5) which gives the internal reference clock, a DTMF signal decoder (6) which outputs the decoding data, and a state recognition and controller (7) which specifies the action modes.

Description

Terminal adapters for tip / ring and V-series interfaces

1 is a diagram of a subscriber-to-network connection in ISDN.

2 is a hierarchical structure diagram of a subscriber-to-network protocol.

3 is a block diagram of the present invention.

The present invention provides a tip / ring adapter for connecting a terminal (eg, telephone, modem, G3 FAX, etc.) having an tip / ring interface to an ISDN to an ISDN, and a terminal having a V-series interface (eg, a PC, a dummy terminal). Etc.) to a terminal adapter that connects to ISDN.

In ISDN, basic subscriber-to-network access method sets 2B + D by setting B channel (64Kbps) used for information transmission and D channel used for transmission of signal information and packet information for circuit switching using existing subscriber line. Figure 1 shows a basic connection configuration between subscriber and network in a manner of exchanging channel information with a subscriber station in an exchange period. In FIG. 1, the ISDN terminal 1 is connected to the ISDN 3 via the subscriber access device 2 according to the connection standard of the S reference point according to the CCITT recommendation, and the non-ISDN terminal 4 is connected to the terminal adapter 5 ( It is connected to the subscriber access device 2 via a TA-Terminal Adapter. Figure 2 shows the hierarchical structure of the subscriber-to-network protocol. The signal information for circuit switching is transmitted on the D channel, and layer 1 maintains bit synchronization and frame synchronization at the access point of each device to form a channel for information transmission of the upper layer, and transmits (receives) a signal. Layer 2 is a data link processing function for organizing messages of higher layers into frames and transmitting them without error to frame ordering, error detection, and recovery functions. Layer 3 is information related to setting up and clearing calls. Perform the processing function. After all, the ISDN terminal 1 and the terminal adapter 5 connected to the S reference point should basically perform layer 1, layer 2, and layer 3 functions according to the CCITT Recommendation for circuit switching, and have a call processing function as a higher layer. .

In the process of expanding and distributing ISDN step by step, it should be possible to provide ISDN services to terminals with existing non-ISDN access standards (R reference points). For this purpose, the terminal adapter uses the electrical and functional characteristics and protocols of R reference points as the S reference points. It should be able to convert into electrical and functional characteristics and protocols.

An object of the present invention is to implement a terminal adapter that is capable of providing ISDN services to non-ISDN terminals by connecting modems, G3 faxes, PCs, and the like, which are generally widely used.

In order to achieve the above object, the present invention provides a tip / ring interface connection function, V-series interface connection function, S reference point connection function, status display function, operation mode setting function, ISDN subscriber-to-network protocol (layer 1, layer 2). It also provides a terminal adapter with layer 3) processing and call control functions.

Hereinafter, with reference to the accompanying drawings will be described an embodiment according to the present invention;

3 is a block diagram of the present invention.

The V-series signal converting unit 1 converts an electrical signal of the V interface into a TTL signal, connects it to the speed matching unit 2, and converts a TTL signal of the speed matching unit 2 into an electrical characteristic of the V interface. The terminal adapter replaces only the V-series signal conversion unit 1 according to the type of the V interface, and the hardware modification can be completed by mounting the associated connector. The interconnection signals of the V interface implemented in the terminal adapter are shown in Table 1.

TABLE 1

Definition of V Interface Interconnect Signal

The speed matching section 2 recognizes the conversion of the interconnection signal of the V interface, or informs the central control section 8 when the information is received from the data line, so that it can be converted to the ISDN subscriber-to-network protocol. In addition, when the call is established, the low speed data of the V interface is transmitted to the B channel (64Kbps) and the rate adaptation function is performed according to the related recommendations to maintain the message synchronization. The speed matching consists of three stages: the data of the first V interface is converted into a constant multiple of 600 baud, the frame is composed of a second multiple of 8 Kbps, and then converted to a third 64 Kbps rate.

The tip / ring end 3 is implemented to provide a terminal connected to the tip / ring interface with the same basic functions that a public telephone network provides to a terminal connected to a telephone line. That is, the tip / ring end 3 performs a power supply function, a hybrid function for separating a signal, and a function for recognizing an ON / OFF state of the handset. The audio signal of the tip / ring termination part 3 is connected to the codec and the filter part 4 (transmitted / received signal) and the DTMF (Dual Tone Multiple Frequency) signal analyzer 6 (received signal). The state is connected to the state recognition and the control unit 7.

The codec and filter unit 4 is controlled by the central control unit 8 through the S-transceiver 5 and converts the audio signal of the tip / ring end unit 3 into a digital signal to adjust the transmission / reception gain. Has the function. In addition, the subscriber-network protocol has a tone generation function because the terminal itself needs to generate a tone (eg, a ring tone, a busy tone, etc.).

The S-transceiver 5 maintains bit synchronization and frame synchronization at the S reference point, and supplies a network synchronization clock to the internal reference clock of the terminal adapter. The S-transceiver is connected to the speed matching section 2, the codec and the filter section 4 using two system buses to receive data of the V interface and the tip / ring interface into the B1 or B2 channel, and the central control section 8 ) Receives the D-channel signal information and multiplexes the B1, B2, and D-channels at the S reference point. Also, according to the related recommendation, the S-transceiver analyzes the E-bit information from the subscriber station (NTE) at the S reference point and occupies the D channel so that up to 8 ISDN units can be connected at the S reference point. Has the function to recover the transmission information.

The DTMF signal analysis section 6 interprets the frequency combinations as shown in Table 2 from the signals received at the tip / ring termination section 3 into digits, respectively, and the decoded data is transmitted to the state recognition and control section 7. .

TABLE 2

Decoding Value of DTMF Signal

The state recognition and control unit 7 is an input / output unit for recognizing the user's behavior information and displaying the call progress state to the user or setting the operation mode of the terminal adapter. LED driving, LCD display, and incoming ring It is implemented for the functions such as relay driving, receiving decoding information of keypad.

The central control unit 8 performs subscriber-to-network protocol and call control functions, transmits and receives signal information to the D channel through the HDLC controller of the S-transceiver, and controls the S-transceiver to activate / deactivate and inactivate It has a function of switching from a state to a low power consumption state.

As a preferred embodiment, the speed converter 2, the tip / ring termination 3, the codec and filter 4, and the S-transceiver 5 use PSB2110, PEB2160 and PEB2085 VLSI from Siemens, respectively. 8) and the state recognition and control unit 7 and the other V-series signal changing unit 1 is implemented by Motorola's MC145429, DTMF signal analysis unit 6 is Motorola's MT8880 and the processor is implemented by Intel's 80C188 VLSI device .

As described above, the present invention has an effect of providing ISDN services by connecting ISDN terminals, such as modems, G3, FAX, and PC, which are generally widely used, to ISDN.

Claims (1)

A V-series signal converter 1 for converting an electrical signal of the V interface into a TTL (Transistor-Transistor Losic) signal and converting the TTL signal into an electrical characteristic of the V interface; A speed matching section (2) for recognizing conversion of the interconnection signal of the V-series signal conversion section (1) or generating an interrupt when information is received from a data line; A tip / ring end portion 3 for providing a terminal connected to a tip / ring interface with the same basic functions that a public telephone network provides to a terminal connected to a telephone line; A codec and filter section 4, which converts the audio signal of the tip / ring termination section 3 into a digital signal and has a transmit / receive gain adjustment function; Is connected to the speed matching section 2, the cotec and the filter section 4; An S-transceiver 5 for maintaining bit synchronization and frame synchronization of the S reference point and supplying the network synchronization clock to the internal reference clock of the terminal adapter; A dual tone multiple frequency (DTMF) signal analysis unit 6 for interpreting a frequency combination from each signal received at the tip / ring end 3 and outputting decoded data; A state recognition and control unit (7) for receiving decoding data from the DTMF signal analysis unit (6), recognizing user behavior information, displaying a call progress state to a user, or setting an operation mode of a terminal adapter; And the state-recognition and control unit 7 and converts the subscriber-to-network protocol according to the interrupt of the speed matching unit 2 and performs a call control function to perform the S-transceiver 5 and the codec and the filter. Terminal adapter characterized in that it comprises a central control unit (8) for controlling the unit (4).