JPH02246653A - Composite ncu type isdn terminal equipment - Google Patents

Abstract

PURPOSE:To increase number of terminal equipments to a maximum number able logically to be connected to a point S/T interface by enabling plural network control unit NCU sections to be connected to a single driver receiver section. CONSTITUTION:Each NCU section of an ISDN terminal equipment 56k (plural equipments in i-set) desiring to acquire access right to a D-channel sends a D-bit to a D-channel of a frame. D-bit to be sent is assigned specifically to the NCU section and a network terminator 52 receiving the plural D bits are set to E bits in a frame on an outgoing S/T point interface 54D as it is and returned to the ISDN terminal equipment. In the ISDN terminal equipment 56k making transmission compares the returned E bits with the sent D bits and the ISDN terminal equipment being dissident stops the transmission of the D bits, Thus, number of terminal equipments up to a maximum number able logically to be connected is increased.

Description

[Detailed Description of the Invention] [Summary] The output of each network control unit is connected to one unipolar-bipolar conversion circuit section connected to the S/T point interface, and the output of the bipolar-unipolar conversion circuit section is connected to the S/T point interface. With regard to the ISDN terminal equipment connected to the input of each network control unit, the multi-drop format to the ISDN S/T point interface is aimed at achieving maximum utilization of the ISDN channel that can be formed at the S/T point interface. one unipolar-to-bibo conversion circuit whose output is connected to the bipolar upstream S/T point interface, and whose input is connected to the S/]' point interface to the 371-point interface; and one bibolar-unibolar converter circuit connected to each unipolar input of the plurality of network control unit sections, the plurality of network control unit sections and one bibolar unipolar conversion circuit connected to each unipolar input of the plurality of network control unit sections. Network control unit I/Part 1
an OR circuit for connecting each of the Nivola outputs to the input of the one unipolar-bipolar conversion circuit;
The unipolar inputs of the plurality of network control units are connected to the outputs of the bipolar-unipolar conversion circuits.

[Industrial application field]

In the present invention, the output of each network control unit is connected to one unipolar-bipolar conversion circuit (driver) unit connected to a 371-point interface, and the output of the bipolar-unipolar conversion circuit (receiver) unit is connected to each network control unit. Connect two ISDN terminals to the input of the unit.

The data communication speed of rsDN terminal devices connected to the 371-point interface of ISDN (Integrated Digital Services Network) is a maximum of 64 Kbps, which is 6 to 20 times the data communication speed of data devices that communicate via existing analog lines. ISDN terminal equipment enables dramatically high-speed data communication. This...
In communication using such a high communication speed line (channel), if the amount of data is the same, the data transfer can be completed in a shorter time than in the case of a conventional low communication speed line. Multiple ISDs to take advantage of this
N terminal devices are connected to the same S/T point interface in a multi-point (multi-drop) manner in order to use the line economically.

[Conventional technology]

FIG. 9 shows a conventional multi-domain single tap connection system.

In this figure, an S/T point interface 54 formed on the terminal side of a network termination device 52 connected to an ISDN exchange 50 and a plurality of ISDN terminal devices 56a (i=1
．． 2. ,,. , 8) are multi-point connected.

Each ISDN terminal device 56 consists of the following components. S/T point interface driver/receiver unit 6oi connected to S/T point interface 54,
, 11 control units]・C and below, N CU (Netiv
ork Control IJnit). ]
section 62□, C0DEC section 648, telephone circuit section 661, handset section 6th 1, communication speed matching (rate adaptation) section 70. and an R point interface section 728. R point interface section 72. There are various types of data terminal devices 80. is connected. Further, reference number 51 in the figure is a U point interface.

In this ISDN home system communication, ISDN
When communicating between a terminal device and a partner ISDN terminal device via the ISDN (-), in response to a call made via one 800 section 62 of the originating ISDN terminal device, the terminating ISDN@ By setting the D channel (communication bus) with the terminal device, both ISDN
B channel (64Kp) formed between terminal devices)
Communication between the two TSDN terminal devices begins via the TSDN terminal. In this communication as well, each TSDN terminal device 56. is one 800
Part 62. The circuit configuration is such that the communication can be performed under connection control.

The 371-point interface used for communication as described above is an ISDN that can be connected to it depending on the electrical conditions (for example, the level and waveform of the signal handled).
There is a limit to the number of terminals installed at a maximum of eight. However, when looking at the 2B+D channel formed as described above on the 371-point interface from a logical condition, the channel cannot be used simultaneously or when the channel is used simultaneously by multiple ISDN terminal devices in packet communication. Considering the format of the signal flowing through the channel, it is configured to allow up to 254 calls.

[Problems to be Solved by the Invention] However, the above-mentioned conventional ISDN terminal device has one 0NCU
The following problem arises because it is configured with only a section.

In other words, calls (telephone calls) that can be controlled by one NCU unit at the same time.
and a number of data communication terminal devices are accommodated in the ISDN terminal device, and the ISDN terminal device can only be connected to the S/T point interface in such a way that the electrical conditions of the S/T point interface are satisfied. There wasn't. For example, if an ISDN terminal device accommodates one telephone and one data communication terminal device, one S/T point interface can accommodate only a maximum of eight telephones and eight data communication terminal devices. Unable to connect.

Also, when performing high-speed packet data communication on an rsDNi terminal device, even if the ISDN terminal device accommodates two data communication terminal devices, one B channel for one data communication terminal device is used. Control (NC
UIIJ control), and at that time, the S/T point interface has a circuit configuration that does not allow communication using the other B channel and D channel, even if they are empty. Ta.

Also, one ISDN terminal device has multiple N
There is also a connection to the S/T point interface of the CU section, but this requires the installation of a switch or the like that requires complicated control. As the number of affiliated terminals increases, it becomes necessary to change the control, etc.

The present invention was created in view of such problems, and is
The object of the present invention is to provide a composite NCU type ISDN terminal device that can make maximum use of the SDN channel that can be formed at the T-point interface.

[Means to solve the problem]

FIG. 1 shows a block diagram of the principle of the present invention. As shown in this figure, the present invention provides a unipolar-to-bipolar converter whose output is connected to a bipolar upstream S/7 point interface 54U for multi-drop connection to an ISDN S/T point interface 54. Circuit L (i=
1.2. . . n), and one bipolar device whose input is connected to the bipolar downlink S/T point interface of the S/T point interface 54 and whose output is connected to each unipolar input of the plurality of network control unit sections 62. A plurality of network control unit (NCU) sections 628, (j=1.
2, . . . , n) and the plurality of network control unit units 62 . an OR circuit 61 connecting each of the unipolar outputs to the input of the one unipolar-bipolar conversion circuit 2;
, and are configured.

[For production]

Each network control unit section 62. The unipolar outputs of , are sent to the unipolar-bipolar conversion circuit 2,
Since the output of the unipolar-bipolar conversion circuit 2 is connected to the unipolar input of each network control unit section 628j, the S/T point interface 5
The number of terminal devices can be increased up to the maximum number that can be logically connected to 4. Its increase does not require complex control.

■SDN because a simple OR connection in the network control unit is sufficient
Expandability can be provided to the terminal device.

〔Example〕

FIG. 2 shows an embodiment of the invention. In this figure, the same components as those in FIG. 9 showing the conventional method include:
The same reference numbers will be given and the description will be replaced. 62i+.
62tt is the N00 section 62! shown in FIG. is the same as 61 connects each of the transmission outputs of these NCU units 6L+ and 62tz to an S/T point interface driver/receiver unit 60. This is an OR circuit for connecting to the drive input of. SZT point interface driver/receiver section 60
The received output of 1 is N00 section 6 2z1. The characteristic part of the present invention is configured by being connected in parallel to each of the 62 bit receiving inputs. Details of this characteristic part are shown in FIG.

In FIG. 3, OR circuit 61.1 is connected to NCU section 62i.
, 6252 each H pulse drive output 63rd.

Connect 63.2 to each H pulse drive driver 90, -1.
)L″, OR circuit 61., BAN(2 (J part 62.l, 6
21. Each ■, pulse drive output 65□, 65i, ・L
Pulse drive driver 92. Connect to. The output of the H pulse reception I/ceiver 9G is output from the Ncu section 62i, 62i.
2 each H pulse reception human power 67. ．． ．． 61=6L pulse receiver 1 noceiver connected in parallel to z 90. i! H pulse drive driver, 928 is ■3 pulse drive driver, 94
, is the transmitting transformer 1.100. is the receiving transformer, 9G,
is I (pulse reception 1 noceiver, 1) 88 is ■-pulse reception 1/ceiver, and these components 90° to 100. are the S/T point interface driver/1 noceiver section 60 in FIG. Consists of .9Oa, 92
i, 94i are unipolar-bipolar conversion circuits 2.i and 94i in FIG. Corresponds to 2.96. . 9Fi, , 100 correspond to the bibolar conversion circuit 4 of FIG.

The transmission transformer 94. The uplink bibo signal (S/T point j two signal) UST output from the uplink S/T point ink face 540 is transmitted to the network terminal device 52 -. A downlink bipolar signal (S
/ T point downstream signal) DST is the receiving transformer 100. is applied to. On the 9th, the output is from the NCU unit 62i, 62*
2, each of which receives the L pulses 69i+ and 69i2 in parallel.

The operation of the present invention in the above configuration will be explained below.

Each of the above-mentioned ISI': multiple ISDs of the IN terminal equipment
When a call is made from the N terminal device, 5° those ■SD
6. Before entering into the description of the process by which any one of the N terminal devices is granted access rights to the D channel, the S/7 point interface 54 is The frame structure (same as that of the conventional multi-point connection method) will be briefly explained. The frame structure is as shown in Fig. 4. 1) The B1 channel, B2 channel and A D channel is formed. Its Bl, B2 channels are 64 Kbps, and the D channel is 16 Khps. Then, F1/-
The F bit in the program is defined as an H pulse, the L bit next to the F bit is defined as an L pulse, and subsequent data is defined as a logic 11.
011 with a pulse 17, each subsequent logic ``0'' has an H pulse, the pulses are alternated, and when a logic ``1'' appears, there is no pulse j7. The frame is constructed in such a way that the D bit (?! number of bits) is named as a control bit specific to the 150 I device.
N terminal devices may be used at the same time, and if the state of simultaneous use continues, the control information will be destroyed [7], so D
The network termination device 52 that received the bit performs the following operations as shown in FIG.
The ISDN terminal device always compares the received E bit with the transmitted D bit,
Monitor the health of control information. If the comparison results in a non-coincidence, the configuration is such that transmission from the ISDNi terminal device is stopped. The transmission signal at the ISDN terminal equipment for each bit of the frame shown in FIG.
The timing of LSUST (see FIG. 3) is determined by DST sent from the network termination device 52. The DH (I (pulse drive signal) and DI, (■, pulse drive signal) are unipolar signals as shown in 1- in FIG. 6, and the UST (S/T upstream signal) is a bipolar signal, S of these signals DH,,DL,...,UST
/'r point 479'7e';<driver 90i, 92.
and transmission transformer 94. The operation timing is also
Figure 6 shows the number. The operation timing of such a transmission signal is determined by DST as described above, and the operation timing of the receiving transformer 100 to which this DST is applied and the receiving transformer 100. The output of is applied to the H pulse reception signal RH and the L pulse reception signal R.
The operation timing of the I (pulse receiver 96□ and L pulse receiver 9) which outputs L is as shown in FIG.

As described above, in response to the DST from the network termination device 52, access rights to the D channel formed between any of the ISDN terminal devices 56 and the network termination device 52 are granted to those multiple ISDN terminal devices 56 and the network termination device 52. Which of the ISDN terminals acquires the information is determined as follows. The control procedure is configured such that the above-mentioned system configuration preserves the conventional D channel access control procedure, so the D channel access control procedure in the present invention also follows the conventional D channel access control procedure. You can gain access to channels.

The above conservation is achieved using the unipolar disjunction (OR circuit 6
1. function) allows electrical characteristics of each NCU unit as seen from the S/T point interface to be
Same as the DN terminal device, and H pulse drive driver 9
The sending timing of each NCU unit to the 〇5 and L pulse drive driver 92□ is the same as before (Figs. 7, 4, and 6).
(See figure) Since it is determined by DST, there is no need to give special consideration to its transmission timing. ISDN
Which of the terminal devices acquires it is determined as follows.

Each NCU unit of the ISDN terminal device 56k (i) that wants to obtain access to the D channel transmits the D bit to the D channel of the frame at the above-mentioned operation timing (see FIG. 6). (See Figures 8 and 5).

The transmitted D bit is uniquely assigned to the NCU section, and the network terminal device 52 that receives this D bit consisting of a plurality of bits directly transmits the D bit to the downstream S/T point as described above. It sets the E bit in the frame on the interface 54D and sends it back to the ISDN terminal device (see FIGS. 5 and 8).

In the ISDN terminal device 56 that transmitted the D bit,
The returned E bit and the transmitted D bit are compared. The ISDN terminal device (see ! in FIG. 8) that does not match stops sending the D bit. This decision to stop is determined based on a priority procedure (conventional method) predetermined for each ISDN terminal device. In this way, the ISDN terminal devices that are inconsistent sequentially stop sending the D bit.

And, in the end, only one ISDN terminal device (
(see C in FIG. 8) reaches a match of the D bit (wins and survives). The ISDN terminal device for which the D bits match acquires the right to access the D channel.

As mentioned above, in the process of acquiring such access rights, the terminal device connected to the NCU unit that has acquired this access right enters the communication control procedure according to the conventional method via the NCU unit and performs the required communication control procedure. communicate.

The above-mentioned access right acquisition processing is performed by N
An H pulse drive driver 90 and an L pulse drive driver 92 by the CU section. Since there is no limit to the number of NCU units for driving the S/T point interface, it is possible to handle access requests up to the maximum number (for example, 127 according to the above) that can be logically connected to the S/T point interface.

Further, in order to increase the number of terminal devices to the maximum number that can be logically connected, there is no need for any complicated control of the terminal devices by an exchange or the like. This is also I
Add extensibility to SDN terminal equipment.

〔Effect of the invention〕

As described above, according to the present invention, by making it possible to connect multiple NCU units to a single driver receiver unit, the number of terminal devices can be increased up to the maximum number that can be logically connected to the S/T point interface. can be increased. It does not require complicated control. This facilitates scalability of ISDN terminal equipment.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the principle of the present invention, Fig. 2 is a diagram showing an embodiment of the present invention, Fig. 3 is a detailed connection diagram of the NCU section and driver/receiver section, and Fig. 4 is the S/T point interface. Figure 5 is a diagram showing the relationship between the D bit and E bit flowing to the S/T point interface, Figure 6 is a diagram showing the driver operation timing of the S/T point interface, and Figure 7 is a diagram showing the driver operation timing of the S/T point interface. FIG. 8 is an explanatory diagram of D channel access control, and FIG. 9 is a diagram illustrating a conventional ISDN terminal device. 1 to 3, 2 is a unipolar-bipolar conversion circuit (H pulse drive driver 90a, L pulse drive driver 921, transformer 94.), 4 is a bipolar-unipolar conversion circuit (transformer 10).
0i, H pulse receiver 96i, L pulse receiver 98
．． ), 615 is an OR circuit, and 62i is an NCU section. Outer Mei no Oki J Kobu C172 Figure 1 f'&1J99b-)7i'-L-'t-r4r'ar
';: JA, XD, 19F5 Figure 3 S/T,! , 4n 22, 1st ^ 9 dorazu J4p 忰2 Imin 2' Fig. 6 Fig.

Claims (1)

[Claims] (1) 1 whose output is connected to the bipolar upstream S/T point interface (54U) in order to connect to the ISDN S/T point interface (54) in multi-drop format.
unipolar-bipolar conversion circuits (2_i) (i=
1, 2, . In an ISDN terminal device having one bipolar-unipolar conversion circuit (4_i) connected to each unipolar input, a plurality of network control unit (NCU) units (62_i_j) (
j=1, 2, . 61_i
), and the plurality of network control units (6_i) are connected to the output of the one bipolar-unipolar conversion circuit (4_i).
1. A composite NCU type ISDN terminal device, characterized in that unipolar inputs of 2_i_j) are connected to each other.