JPH0824397B2 - Subscriber line multiplexer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is particularly suitable for efficiently transmitting a plurality of types of information signals such as voice, data, and images between a switchboard and a subscriber terminal. Multiplex transmission apparatus. The application of this device is not limited to public communication networks, but can be applied to general communication networks.

[Conventional technology]

When a plurality of different types of information, such as voice, digital data, image information, etc., are transmitted to a subscriber, these are multiplexed by a method such as time division multiplexing or wavelength multiplexing and transmitted by one subscriber line. I often do it. Conventionally, there are many examples of transmission of such multiple signals, and typical examples are ICC 84, procedure, and
1145 to 1149 (ICC'84, Proceedings, pp1145-11
There is a transmission system shown in 49). The outline of the technical contents will be described with reference to FIG. The three kinds of information signals a, b, c pass from the trunk lines 11, 11 ', 11 "through the exchange a22, the exchange b22', and the exchange c22", respectively, by the different intra-station transmission lines 23, 23 ', 23 " The signal is input to the subscriber line terminal station 24. The subscriber line terminal station 24 time-division-multiplexes each signal and sends it to the subscriber line 15. The sent signal is sent by the subscriber line terminal device 26 which is a peripheral node. After receiving and separating each signal, they are transmitted to the terminal a17, terminal b17 'and terminal c17 ", respectively.

[Problems to be solved by the invention]

In the transmission system as shown in FIG. 6, the frame of the time division multiplexed signal transmitted by the subscriber line 15 is fixed in a predetermined format. For this reason, it is difficult to newly add information other than the predetermined type of information. Further, in the case of performing multiple access with one of the exchanges and transmitting a larger amount of information, it is necessary to secure a corresponding portion in advance in the signal frame transmitted through the subscriber line 15. is there. An example of the frame structure of such a time division multiplexed signal is shown in FIG.

F271 is a frame signal and time slots a272, b27
5 and c276 correspond to information a, b and c, respectively, and a ₁ 273,
Reference numeral a ₂ 274 is a time slot required to multiplex the information a, and 277 is a spare time slot for future expansion. That is, in the conventional subscriber line transmission system, it is necessary to always secure a transmission capacity capable of simultaneously transmitting all information signals.

However, it is impossible to always transmit such a large amount of information from the capability of the network side. In such a subscriber transmission system, most of the signals that are in an empty state are transmitted, which is inefficient. Furthermore, it is very uneconomical to prepare the bandwidth for new information transmission expected to occur in the future.

The same applies to the intra-station transmission lines 23, 23 ', 23 "from the respective exchanges 22, 22', 22" to the subscriber line terminal 24.

An object of the present invention is to solve the above problems and to provide a subscriber line multiplexer which can efficiently use a subscriber line and an intra-station transmission line.

[Means for Solving the Problems] In order to achieve the above-mentioned object, in the present invention, for example, as shown in FIG. 1, a plurality of exchanges 12, 12 ', 12 "and a subscriber accommodating the plurality of exchanges are provided. A subscriber line terminal station 14, intra-station transmission lines 131 to 134 connecting the subscriber line terminal station and the exchange, a plurality of subscriber terminals 17, 17'17 ″, and a plurality of subscriber terminals for a home extension line.
A subscriber line terminating device 16 accommodated via 18-18 ″ and a subscriber line 15 as a bidirectional transmission line connecting the subscriber line terminating device and the subscriber line terminal are provided. Then, at least the subscriber line 15 is included in the time division multiplexed signal transmission line so that the subscriber line 15 is connected between the plurality of subscriber terminals 17, 17 ', 17 "and the plurality of exchanges 12, 12', 12". In the subscriber line multiplexer for transmitting information signals, the exchanges 12, 12 ', 12 "are connected to the intra-station transmission lines 131, 13".
2, 133 and 134 are connected in series to the subscriber line terminal station 14, and the subscriber line terminating device 16 to the exchanges 12 to 12 ″ side including the serially connected exchanges and intra-station transmission lines. Is used as a loop time-division multiplexed signal transmission line, and for the time-division multiplexed transmission of information signals, the subscriber line terminating device 16 uses the multiplexed signal configuration of the time-division multiplexed signals. Means for variably setting according to the call generated from the subscriber terminal, that is, in the case of calling from the terminal, for example, in multiplexing and transmitting the information signal,
At least means for allocating a time slot corresponding to a used band, that is, setting of a multiplexed signal structure, indicating which time slot to which time slot in the time division multiplexed frame is to be used for transmission of the information signal of the terminal shall be provided. . As a result, for example, as shown in (1) and (2) of FIG. 2, the multiplexed signal according to the call from the terminal, such as (1) in some cases and (2) in some cases. The subscriber line terminating device 16 rewrites the configuration information.

Further, the subscriber line terminating device 16 exchanges signals with the subscriber terminal, so that it changes the multiplexed signal configuration information (this information is not shown, for example, in the frame signal 191 of FIG. 2). It is encoded and included as multiplexed signal configuration information, and more specifically, the multiplexed signal configuration information is, for example, information inserted in the overhead of a synchronous digital hierarchy transmission frame of the international standard ITU-T.) And a decoding means for decoding the time slots, and the time slots are variably distributed to the subscriber terminals according to the multiplexed signal configuration, or the signals from each subscriber terminal are variably assigned to predetermined time slots of the time division multiplexed signal. And a decoding control means for decoding the multiplexed signal configuration information, including a control means for inserting into the. On the other hand, each of the exchanges has a decoding means for decoding the time slot assignment information set by the subscriber line terminating device to be accessed by the own exchange and accessing a predetermined time slot, and from the subscriber terminal to the own exchange. And a decoding control means for decoding multiplexed signal configuration information, including control means for extracting the information signal from the predetermined time slot or inserting the information signal addressed to the subscriber terminal from the own exchange in the predetermined time slot.

The processing itself by the decoding control means is the same as the processing for a normal time division frame. In addition, the multiplexed signal configuration information is information that is exchanged in order to commonly recognize the time slot allocation state of the time division multiplexed signal in which a plurality of information signals are time division multiplexed.

In this case, the decryption control means performs processing so as to pass through the own exchange without accessing the time slot when the transmission information is decrypted so that the own exchange does not need to access it.

As another invention for achieving the above object, for example, as shown in FIG. 3, a means for separating the multiplexed signal configuration information is provided in the subscriber line terminal station 34, and the separation result is referred to as the loop transmission line. Is sent to the control device 38 via another intra-station transmission line 37, and the control device 38 decodes the multiplexed signal configuration information and sends the control signal to each exchange. By this, the extraction of the information signal from the predetermined time slot,
Alternatively, the information signal may be inserted into a predetermined time slot or the transmission information may be passed. In this case, there is an advantage that it is not necessary to equip each exchange with means for decoding the multiplexed signal configuration information.

In each of the above-mentioned configurations of the invention, all or some of the plurality of subscriber terminals may be configured to be connected to the subscriber line terminating device by a loop-type extension line or a bus-type extension line.

[Action]

The reason why the conventional subscriber transmission system is inefficient is that various information is transmitted even though the amount of information actually propagated through the subscriber line is limited by the call volume of the subscriber and the transmission capacity of the network. They had installed a subscriber line with a capacity large enough to carry all. In order to improve this efficiency, it is necessary to limit the subscriber line to a necessary and sufficient transmission capacity. In order to limit the transmission capacity and allow various kinds of information to be transmitted, the combination of the contents of the transmission signal may be made variable according to the request from the subscriber. Considering the case of transmitting various information by time division multiplexing, for example, the structure of the time division multiplexing frame may be changed according to the contents of the call each time a call from the subscriber occurs. In this way, the subscriber line can be used sufficiently efficiently.

On the other hand, considering the intra-station transmission path, the total amount of information propagating through these cannot exceed the transmission capacity of the subscriber line. Therefore, it is inefficient that each intra-station transmission line in the case of the conventional device must secure a transmission capacity corresponding to the maximum information amount. The cause is that the transmission lines within each station are wired in a star pattern (radial from the subscriber line terminal) with respect to the subscriber line terminal. Therefore, as in the present invention, if each switching exchange is connected in a loop with a transmission line and a part of the loop is used as a subscriber line, the transmission capacity of the intra-station transmission line to each exchange is added. Since it matches the transmission capacity of the main line, it is possible to completely eliminate the inefficient portion that has conventionally occurred in the intra-station transmission line.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention. The three types of information a, b, c are input to the corresponding exchange a12, exchange b12 ', and exchange c12 "from the trunk lines 11, 11', 11", respectively. Each exchange 12, 12 ', 12 "and subscriber line termination equipment
Reference numeral 16 is an intra-station transmission line 131, 132, 133, 134 and a subscriber line 15.
Are connected in a loop. The subscriber line terminal station 14 relays the signal from the exchange and the signal from the subscriber line terminating device. The subscriber line terminating device 16 has terminals 17, 17 ', 1
The time-division multiplexed signal structure of the loop transmission line is changed according to the call generated from 7 ″.

The configuration information of the time division frame, that is, the multiplexed signal configuration information set according to the call generated from each terminal 17, 17 ', 17 "is superimposed on the frame signal F191 as shown in FIG. Reference numeral 198 denotes a time slot set by the multiplexed signal structure, that is, depending on a call from the terminal, at some time, as shown in FIG. The signal structure is one, and the multiplexed signal structure is composed of the time slots of information b and c as shown in FIG.
As described above, the contents of the transmission path are rewritten and changed so as to have a multiplexed signal structure of a ₁ + a ₂ + a ₃ for the multiplex of the information a. When new information needs to be transmitted, it can be used as shown in FIG. 2 (5). Such multiplexed signal configuration information is sent to each exchange 12, 1 through a loop-shaped transmission line.
2 ', 12 ". In each of the exchanges 12, 12', 12", the above-mentioned multiplexed signal configuration information is decoded, and when there is a request for transmission of an information signal from the own exchange to the terminal, The information signal is multiplexed in a predetermined time slot of the time division multiplexed frame according to the multiplexed signal configuration information. When there is no request to the own exchange, the operation of multiplexing is not performed and the time division multiplexed signal is passed.

The signals multiplexed as described above are loop transmission lines (15,
131 to 134) to reach the subscriber line terminating device 16, where they are separated according to the multiplexed signal configuration information, and each terminal 17, 1
7 ', 17 ". On the other hand, the upstream information from the terminal which received the information signal is exchanged by the subscriber line terminating device 16 into a time division multiplexed frame on the loop transmission line (15, 131-134). Instead of the transmission information from, it is multiplexed.

In the present embodiment, the multiplexed signal configuration information is superimposed on the time division multiplexed frame and transmitted to each exchange, and each exchange directly decodes it, so that another multiplexed signal configuration controller is not required. There is.

Further, the multiplexed signal configuration information can be separately set for upstream and downstream. In that case, it becomes possible to cope with the transmission of upper and lower different speed information.

FIG. 3 is a block diagram showing another embodiment of the present invention.
The point that the multiplexed signal configuration information is superimposed on the frame signal in the subscriber line terminating device 36 is the same as in the embodiment of FIG. In this embodiment, the subscriber line terminal station 34 separates the multiplexed signal configuration information from the time division multiplexed frame, and the separated multiplexed signal configuration information is transmitted by the intra-station transmission line 37 different from the loop transmission lines 331 to 334. It is transmitted to the control device 38. The control device 38 decodes the multiplexed signal configuration information and controls each of the exchanges 32, 32 ', 32 "by using the intra-station transmission lines 39, 39', 39". Each exchange
32, 32 ', 32 "separate the information from the subscriber from a predetermined time slot of the time division multiplex frame by a control signal from the control device 38, and multiplex the information to the subscriber.

According to the configuration of the present embodiment, it is not necessary for each of the exchanges 32, 32 ', 32 "to decode the multiplexed signal configuration information, so that the configuration can be simplified.

FIG. 4 is a block diagram showing still another embodiment of the present invention. Network Unit A16 _A is coupled to the switch a12, exchange b12 'by the loop type transmission line consisting of a subscriber line 15 _A and the station transmission path _{131 A, 133 A, 134 A} . Further, the subscriber line terminating device B16 includes the subscriber line 15 and the intra-station transmission lines 131, 13
The switch a1 has a loop transmission line composed of 2, 133, and 134.
2, the exchange b12 'and the exchange c12 "are connected. The subscriber _A by the subscriber line terminating device A16A is connected to the information a and the information b.
Is a subscriber who needs but does not need the information c.

According to this embodiment, the same transmission system can be applied to subscribers who do not need the information c for the time being, and the transmission path can be used efficiently. Further, there is an advantage that it is possible to omit a part of the intra-station transmission path without affecting other parts. Further, there is an advantage that it is possible to easily deal with the case where the subscriber newly needs the information c.

FIG. 5 is a block diagram showing another embodiment of the present invention. In the case of this embodiment, the subscriber has two terminals related to the information a. The two terminals 17a and 17a 'are
Subscriber line terminator 1 connected in a loop by premises line 18 _A
Connected to 6.

According to this embodiment, when the subscriber side is seen from the exchange a12, the terminal a17a and the terminal a'17a 'can be regarded as the same terminal requesting the dual connection. Therefore, the subscriber line terminating device 16 It has the advantage that no changes are required in the station side. Further, the terminal side interface of the subscriber line terminating device 16 is also an interface that is originally compatible with multiple access, and it is easy to connect two terminals a and a '.

In each of the embodiments described above, the case where the multiplexed signal configuration information is superimposed on the frame signal of the time division multiplexed frame has been described. This can be transmitted using another common line signaling channel without being superimposed on the frame signal.

In each of the above embodiments, the case where the exchange is connected has been described. The same effect can be obtained when this is used as a different type of station device such as a packet multiplexing device or a video selection device, or a combination thereof.

Further, in each of the above embodiments, the case where three types of exchanges are connected has been shown. It goes without saying that the same effect will be produced when this is further increased.

In the embodiment shown in FIG. 5, two terminals a and a'are connected to the subscriber line terminating device 16 via the loop extension 18 _A , but this is a bus (bus line) type transmission line. Even if the terminal a and the terminal a'are respectively connected to the bus from the subscriber line terminating device 16, the same effect as in FIG. 5 can be produced.

〔The invention's effect〕

According to the present invention, in a subscriber transmission system for transmitting a plurality of types of information, the subscriber line terminating device and various exchanges are connected by a loop-shaped transmission line, and its transmission capacity is set to a level sufficient for normal use. By limiting and setting the time-division multiplexed signal structure propagating through the loop transmission line variably according to the call from the subscriber terminal, the subscriber line and the intra-station transmission line can be provided with a necessary and sufficient transmission capacity. It becomes possible to configure, and in the past, it was necessary to have a subscriber line transmission capacity capable of transmitting all kinds of information at the same time, and in the normal use, most of them including the intra-station transmission line were not used. The same function can be realized with a small-capacity transmission line, which has a great effect on the economicization and efficiency of the transmission system.

Furthermore, even if new information transmission becomes necessary, it can be added simply by incorporating a new information station into a part of the loop-shaped transmission line, and a highly scalable multiplexing transmission device can be configured. There is also an effect.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention, FIG. 2 is a diagram showing an example of the configuration of a time division multiplexed signal frame used in the embodiment of the present invention, FIG. 3, FIG. 4 and FIG. FIG. 6 is a block diagram of another embodiment of the present invention, FIG. 6 is a block diagram of a conventional example, and FIG. 7 is a diagram showing a configuration example of the time division multiplexing frame.

Claims (4)

[Claims] 1. A plurality of exchanges, a subscriber line terminal station accommodating the plurality of exchanges, an intra-station transmission line connecting the subscriber line terminal station and the exchange, a plurality of subscriber terminals, and a plurality of subscriber terminals. Of the subscriber line as a bidirectional transmission line connecting the subscriber line terminating device and the subscriber line terminal station. In a subscriber line multiplexer that includes at least the subscriber line in a time division multiplexed signal transmission line and transmits information signals between the plurality of subscriber terminals and the plurality of exchanges, The exchange is connected in series to the subscriber line terminal through the intra-station transmission line, and the transmission line seen from the subscriber line terminating device to the exchange side including the exchange and the intra-station transmission line connected in series. Is a loop-shaped time-division multiplexed signal transmission line. For decentralized transmission, the subscriber line terminating device includes at least means for variably setting the multiplexed signal structure of the time division multiplexed signal according to a call generated from the subscriber terminal, and the multiplexed signal that changes. The configuration information is decoded and the time slots are variably distributed to the subscriber terminals according to the multiplexed signal configuration, or the signals from each subscriber terminal are variably assigned to the predetermined time slots of the time division multiplexed signal. And a decoding control means for inserting the multiplexed signal configuration information, wherein each exchange is set by the subscriber line terminating device,
The local exchange deciphers the time slot allocation information to be accessed and accesses the predetermined time slot, and extracts the information signal addressed to the local exchange from the subscriber terminal from the predetermined time slot or the local exchange in the predetermined time slot. A subscriber line multiplexer, comprising: decoding control means for inserting multiplexed signal configuration information into which an information signal addressed to a subscriber terminal is inserted. 2. The decryption control means in the exchange performs processing so as to pass through the own exchange without accessing a time slot when the transmission information is decrypted so as not to be accessed by the own exchange. The subscriber line multiplexer according to claim 1, characterized in that 3. A plurality of exchanges, a subscriber line terminal station accommodating the plurality of exchanges, an intra-station transmission line connecting the subscriber line terminal station and the exchange, a plurality of subscriber terminals, and the plurality of subscriber terminals. A subscriber line terminating device for accommodating the subscriber terminal of (1) through a premises line, and a subscriber line as a bidirectional transmission line connecting the subscriber line terminating device and the subscriber line terminal station. In a subscriber line multiplexer that includes at least the subscriber line in a time division multiplexed signal transmission line and transmits information signals between the plurality of subscriber terminals and the plurality of exchanges, The exchange is connected in series to the subscriber line terminal through the intra-station transmission line, and the transmission line seen from the subscriber line terminating device to the exchange side including the exchange and the intra-station transmission line connected in series. Is a loop-shaped time-division multiplexed signal transmission line. For decentralized transmission, the subscriber line terminating device includes at least means for variably setting the multiplexed signal structure of the time division multiplexed signal according to a call generated from the subscriber terminal, and the multiplexed signal that changes. Decoding control of multiplexed signal configuration information, in which time slots are variably distributed to subscriber terminals according to the configuration, or signals from each subscriber terminal are variably inserted into predetermined time slots of time division multiplexed signals. The subscriber line terminal station is provided with means for separating the multiplexed signal configuration information, and the result of this separation is sent to the control device via an intra-station transmission line other than the loop transmission line, The control device decodes the multiplexed signal configuration information and sends a control signal to each exchange, and each exchange receives an information signal from a predetermined time slot according to the control signal resulting from the above decoding. A subscriber line multiplexer, which performs sampling of information, insertion of an information signal into a predetermined time slot, or transmission processing of transmission information. 4. A plurality of subscriber terminals, all or a part of which are connected to the subscriber line terminating device by a loop-type extension line or a bus-type extension line. The subscriber line multiplexer according to any one of items 1 to 3.