JPH0720098B2 - Multiplexing method for low-speed terminals in high-speed multiplex transmission equipment - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for multiplexing low speed terminals in a high speed multiplex transmission apparatus.

2. Description of the Related Art Conventionally, this type of multiplexing method for low-speed terminals has been carried out by the frame structure shown in FIG.

In FIG. 3, F in the frame is 1 bit representing the beginning of the frame, and T1 to Tn are, for example, 8 bits and 64 bits.
It is a time slot fixed to the transmission capacity in Kb / s.

Any one of the T1 to Tn time slots is used as 64 Kb / s1 channel, or one channel is compressed to 32 Kb / s and used as two channels, or one channel is 16 Kb / s. In this case, the low-speed data is multiplexed and transmitted by compressing it into four channels and multiplexing them into four channels for use.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the conventional multiplexing method, since time slots are fixed and assigned for each terminal transmission rate (b / s), time slots for low-speed data are dynamically assigned. There was a problem that I could not do it.

Therefore, an object of the present invention is to provide an excellent multiplexing method capable of dynamically allocating time slots for constant speed data.

Means for Solving the Problems In order to achieve the above object, the present invention provides time slot allocation information including low-speed data channel information by a common line signaling method in which a line connection information notification channel is the end of a time slot. The terminal information is dynamically exchanged and transmitted according to various transmission speeds by passing it between the high-speed multiplex transmission devices.

Effect According to the present invention, it is possible to identify which terminal uses which channel by the time slot allocation information of the line connection information notification channel. Therefore, in communication between high-speed multiplex transmission devices, it matches the attributes of the terminal such as the transmission speed. It is possible to perform such exchange transmission and dynamically allocate time slots for low-speed data.

Practical Example FIG. 1 is a block diagram showing a configuration example of a system suitable for carrying out the method of multiplexing low-speed terminals according to the present invention.
Is a switching transmission device such as a PBX or a multimedia multiplexing device, and high-speed multiplexing transmission devices 3 and 4 are connected in series to the switching transmission devices 1 and 2, respectively. It is connected by a high-speed multiplex interface 5 of 15 Mb / s or Mb / s.

Hereinafter, a transmission method for performing communication (exchange transmission of terminal information) between the exchange transmission devices 1 and 2 via the high-speed multiplex transmission devices 3 and 4 will be described.

The frame structure of low-speed terminal multiplexing applied in this embodiment is as shown in FIG.

In FIG. 2, F in the time division multiplex frame is 1 bit that sets the beginning of the frame, and T _{1 to} Tn are 64 Kb / s.
Unit time slot, t1 to tl are child time slots formed by dividing the 64 Kb / s unit time slot into the following units, and these child time slots t1 to tl are assigned as low-speed data channels. .

The “l” of the child time slot tl is the “number of channels that can be accommodated” in the table below.

This table displays the number of multiplexed channels according to the transmission rate for each terminal.

In addition, since the terminal transmission rate of 1200 b / s in the table is start / stop synchronization, the number of channels when sampling is performed at 9600 HZ is displayed as "the number of channels that can be accommodated" 5.

In addition, “bearer rate” in the table adds 2 bits of F bit which is the first bit of the envelope and S bit which is the last bit of the envelope to 6 bits of terminal information of D _{0 to} D ₅ , for example. do it, Is the speed for transmitting in the form of an envelope. Therefore, according to the example, the bearer rate is 8/6 times the terminal transmission rate (b / s).

Therefore, in FIG. 2, in a time slot of T1 to Tn in units of 64 Kb / s, for example, in the case of a data terminal having a terminal transmission rate of 9600 Kb / s, t1 to t5 child time slots (5 channels) Are assigned, and low-speed data is multiplexed and transmitted by the five channels (t1 to t5).

Also, nth (for example, if the interface is 1.5 Mb / s, n
= 24.2 Mb / s interface, n = 32) time slot (final time slot in the frame) is used as the line connection information notification channel (control information channel for signaling, etc.) Time slot allocation information including channel information,
That is, the time slot and child time slot number and channel attribute assigned to the channel of low speed data of 64 Kb / s or less or high speed data of 64 Kb / sxn are transferred between the high speed multiplex transmission devices 3 and 4. That is, mutual communication is performed as bucket communication using the HDLC (High Level Data Link Control) procedure.

The line connection information element includes a time slot number of T1 to Tn in units of 64 Kb / s, an attribute of the time slot, a child time slot number of t1 to tl used for the low speed data, and the like. (See Figure 2). The attributes are 64K / 48K / 9.
It represents a terminal transmission rate of 6K / 4.8K / 2.4K / 1.2Kb / s, and the multiplicity is 1/1/5/10/20/5, respectively (see the table above).

Therefore, the child time slot assigned to the low-speed data terminal is determined by the combination of the time slot number of 64 Kb / s unit and any one child time slot number of t1 to tl. The value of l is the multiplicity (the number of channels that can be accommodated).

Furthermore, a high-speed channel of 64 Kb / sxn can be assigned, and the attribute is 64 Kb / sxn.

Thus, according to the above embodiment, Tn time slot and tl child time slot, it is possible to dynamically allocate channels of various transmission rates from low speed data of 1200b / s to high speed data of 64Kb / sxn, The terminal information can be dynamically exchanged and transmitted according to the channel units.

Further, according to the above-mentioned embodiment, there is an extended effect that the communication information can be notified to the both communication control devices through the line connection information notification channel.

EFFECTS OF THE INVENTION As is apparent from the above-described embodiment, the present invention uses a time division multiplexed frame for a plurality of time slots of a certain terminal transmission rate unit and a terminal within each time slot of the terminal transmission rate unit in units smaller than that. The configuration is such that it can be divided into multiple child time slots according to the transmission rate, and the time slot allocation information that includes low-speed data channel information is provided by the common line signaling method in which the last time slot in the frame is the line connection information notification channel. Since it is designed to be transferred between high-speed multiplex transmission equipment, low-speed data time slots (channels) can be efficiently and dynamically allocated, and exchange transmission that matches terminal attributes can be performed in low-speed data channel units. It can be done dynamically.

Furthermore, the method of the present invention can flexibly cope with communication between high-speed multiplex transmission devices interconnected by a high-speed multiplex interface such as 1.5 Mb / s or 2 Mb / s.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of a system suitable for implementing the method of the present invention, FIG. 2 is a conceptual diagram showing a configuration example of a time division multiplex frame used in the method of the present invention, and FIG. It is a conceptual diagram which shows the structural example of the frame used. 1, 2 ... Exchange transmission device, 3, 4 ... High-speed multiplex transmission device, 5 ... High-speed multiplex interface, T1-Tn ... Time slot, t1-tl.

Claims (1)

[Claims] 1. When performing communication between exchange transmission devices connected to a pair of high-speed multiplex transmission devices interconnected by a high-speed multiplex interface, time division multiplex frames are transmitted at a plurality of times in a certain terminal transmission speed unit. The slot and each of its time slots are configured so that they can be divided into multiple child time slots according to the terminal transmission rate in units of the terminal transmission rate or less, and the last time slot in the frame is used as the line connection information notification channel. By the line signaling method, time slot allocation information including low-speed data channel information is transferred between the high-speed multiplex transmission devices, so that terminal information can be dynamically exchanged and transmitted according to various transmission speeds. A method for multiplexing low-speed terminals in a high-speed multiplex transmission device.