JPS5975730A - Synchronizing signal priority type random access transmitter - Google Patents

Abstract

PURPOSE:To access aperiodically generated data at random in a free time which is generated specifically by providing a time slot monitor, detector which monitors its output and detects the in-use mode of transmission timing, and access control circuit which sends out an aperiodic signal burst. CONSTITUTION:The time slot monitor 60 discriminates whether a signal is present or not by the detector 600 and the discrimination value is inputted to a shift register 601. A transmission timing detector 61 detects the transmission timing of time slots by a reference signal generator 6100, switch 6101 which allows the output of a time slot sweeper 602 to pass only when the output of the generator 6100 is ''1'', smoothing circuit 6120, and discriminator 6103 which discriminates the output of smoothing circuit. Then, whether a transmission period is periodic or not used is known from each output at a terminal 101. An access control circuit 70 stores transmission data in a buffer memory 701 temporarily from an input terminal 102 and then reads and sends it to a modulator according to the output of a transmission timing oscillator 702 which generates a transmission timing signal corresponding to idle timing by the detector 61.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a random access transmission system that coexists with a distributed processing adaptive time division multiplex transmission system.

In traditional communication networks, the switching function that connects each other and the multiplex transmission function that connects each switching function were clearly separated. In such a situation, mutual communication begins only after an exclusive communication line is established between the terminals desiring connection. That is, a line setting procedure (call processing) is always required prior to communication. If the information sent and received between terminals is in the form of telephone voice, fax, file transmission, etc., and the transmitted information is regularly and continuously transmitted for a considerable period of time, this call processing will not reduce the transmission efficiency. .

In recent years, in the information processing field, there has been a growing trend toward distributed processing based on computer networks, and there has been a demand for efficient data transmission between computers or between terminals and computers, which occurs non-periodically. Conventionally, this problem has been dealt with by providing random access networks exclusively for computer networks. However, the expectations placed on data communications by society are not satisfied by the proliferation of these two exclusive networks, and new transmission media that can more organically and flexibly integrate and accommodate each network are being sought. It will be done. Since such transmission media are strongly required to have wide-area and general-purpose characteristics from an economic standpoint, they are not compatible with traditional circuit-switched signals that dislike delays between transmission and reception and have poor delay correction and absorption functions. coexistence is expected.

One way to satisfy the above contradictory demands is to give priority to signals suitable for circuit switching, such as voice, and use regularly occurring idle time to randomly access non-periodically generated data. It may be possible to treat it with technology.

SUMMARY OF THE INVENTION An object of the present invention is to provide a periodic signal priority type random access transmitter that embodies the related new transmission medium.

The invention consists of a frame 1. having 5 time slots. A periodic signal transmitting station that transmits its own burst signal every arbitrary frame using an evening/rm slot arbitrarily selected by each station based on In a time division transmission system in which a non-periodic signal sending station is mixed, a time slot monitor detects the presence or absence of a signal in each time slot in a received frame signal; for each of the five time slots. A transmission timing detector that observes the time slot monitor output at all permissible transmission timings and detects whether the transmission timing is unused, used periodically, or used aperiodically. and: an access control circuit that transmits an aperiodic signal burst using a time slot other than the periodically used transmission timing. .

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1(a) shows a transmission signal time series of a conventionally used time division multiplex multiple reef access (TDMA) system. The same transmission signal pattern is repeated in units of a fixed rate indicated by Tf in the figure. In other words, stations A and B periodically send out their own burst signals at the same position in the frame.

FIG. 1(b) shows a burst of a multi-period ', I' DMA signal. The signal of station A transmits its own burst for each frame as in Fig. 1(a), but the signal of station B,
Station C sends its own burst every 2 Frenos. That is, 13. This means that station C is transmitting its own burst at twice the frequency of station A. For general ゛, n frame 1,
It is possible to send out X self-bursts every time, and it is possible to send out self-bursts to station A at n times the period. In this case, by observing only a few frames, it appears that each time slot is being used at irregular intervals.
It is very easy to identify whether periodic time slots are used or not.

Figure 2 shows the usage status of the 6 time slots in a frame, as shown in Figure 1 (b), simply averaged for each frame. Since it is being sent, the average value is 1, and slots 3 and 4 are 13.
,' Since station C transmits every two frames, the average value is 0.
．． 5 is shown. In such a simple average, the first
Although it is known that one time slot is used every time, it is unclear how the third and fourth time slots are used. In order to solve this problem, a reference signal as shown in FIG. 3 is used.

The reference signal 7 in FIG. 3 becomes 1 in odd frames. The waveform and reference signal 8 are waveforms that become 1 in even frames.

When reference signal 7 is applied to the frame signal in Figure 1(b) and the fourth time slot (burst of station C) is observed, it is immediately clear from Figure 4(a) that it is unused in this period. I understand. Similarly, when reference signal 8 is applied to the frame signal in Figure 1(b) and the third time slot (burst of station B) is observed, it is found from Figure 4(b) that it is unused in this cycle. is similarly understood. Also, if we average the usage status of each time slot (1 when used, O when not used) only when the reference signal is 1, if a burst with the same period as the reference signal appears in a time slot, Its average output is always 1. As a result, by comparing the received signal with the reference signal that is equal to a certain transmission period as shown in Figure 3, it is possible to determine whether it is empty or in use at that transmission period. I understand. When the previous average output reaches a value between O and 1, it can be seen that it is the beginning or end of a periodic signal, or the reception of a random periodic signal.

FIG. 5 is a diagram showing actually necessary reference signal groups. In the figure, 40 is for every frame period, 41 and 42 are the same as reference signals 7 and 8 in FIG. It changes to

FIG. 6 is a block diagram of an embodiment of a time slot monitor 60 that detects the presence or absence of a signal on each time slot, and a transmission timing detector 61 that detects the period in which each time slot is used. FIG.

A received signal is applied from an input terminal 100, and an input power detector 600 identifies the presence or absence of a signal on a time slot. This identification value is inputted into the shift register 601 one after another in the time thrower 1 period, and after this operation is completed for one frame, the usage status of each time slot is determined by the contents of the shift register 601.
It can be observed individually through the 02 switch.

Transmission timing detection for an arbitrary time slot is
Reference signal generator 61 that generates the reference signal shown in FIG.
00, the time slot sweeper 6 only when the output is 1
A switch 6101 that passes the output of 02, and a smoothing circuit (low-frequency F wave device) 6102 that averages the output of the switch.
, determine whether the circuit output is 0, 1, or an intermediate value.
This is performed by a discriminator 6103 that identifies by value. The same blocks as block 610 are prepared only for the types of reference signals, and are composed of the same components except that the waveforms generated by the reference signal generators of each block are different. When each output of the output terminal 101 is 1, it indicates that the sending cycle is used periodically, and when it is 0, it indicates that it is not used.

Note that in order to monitor all time slots at the same time, a transmitting timing detector 61 is provided for each time slot, or a smoother (low-frequency P wave detector) 610 in block 610 is provided.
2 are prepared as many as the number of time slot nodes, and are switched in a time division manner in synchronization with the time slot sweeper 602, and the time slot sweepers 6102 and 2 are sequentially switched within the time period in which the smoother 6102 is connected to the discriminator 6103. It is necessary to read the identification value for.

FIG. 7 is a diagram showing a process diagram of an embodiment of the present invention.

In the figure, 80 is an antenna, and 90 is a circulator for branching input and output to the antenna. 60 is a time slot monitor, and 61 is a sending timing detector, each of which is the same as in FIG. 70 is an access control circuit, and the transmission data is stored in the buffer memory 701 from the input terminal 102. Depending on the output,
It is read out and fed to the modulator.

As described above, according to the present invention, each station independently determines the empty transmission timing, not only in the TDMA system in which a self-burst is sent out for several frames in the outgoing direction, but also in multi-period TDMA system that allows bursts to be sent out every n frames. It is possible to detect this and send out an aperiodic signal without interfering with periodic signals.

According to the access control procedure presented in this paper, priority is given to periodic signals, so there is a possibility that all time slots will be occupied by the same signal. For this reason, when a certain transmission cycle is used exclusively for non-periodic signals, there is a possibility that other stations do not recognize it as a periodic signal, so the transmission signals at both ends are stabilized in anticipation of receiving disturbances. After that, it is necessary to complete the call setup.

[Brief explanation of the drawing]

FIG. 1(a) is a diagram illustrating a frame structure used in conventional time division multiplex transmission. FIG. 1(1)) is a diagram for explaining a frame structure used in multi-period time division multiplex transmission that allows burst transmission every 11 frames. Figure 2 is a conceptual diagram obtained by simply averaging the usage status of each time slot in the frame of ML diagram (b), and Figure 3 is a conceptual diagram for observing the usage status of time slots divided into odd and even frames. The figure which shows the example of the reference signal used for. Figures 4 (a) and (b) show how the time slot usage status of the time division multiplexed transmission signal in Figure 1 (b) is observed divided into odd and even frames using the reference signal in Figure 3. Diagram showing. FIG. 5 is a diagram showing an example of a general reference signal. FIG. 6 is a block diagram of a time slot monitor and a sending timing detector. In the figure, 6θ is a time slot monitor, and 61 is a sending timing detector. FIG. 7 is a block diagram of an embodiment of the present invention. In the figure, 60 is a time slot monitor, 6 is a sending timing detector, and 7o is an access control circuit. Figure 1 '1. ．． ．． (b) Figure Z--.址 S Group IJ Dou 4 [So (C Li (l)) Bone θ Figure + 7 En

Claims (1)

[Claims] A periodic signal transmitting station that transmits its own burst signal every arbitrary frame using a time slot arbitrarily selected by each station based on a 71 norm having five time slots, and a signal of the periodic signal transmitting station. In a time-division transmission system in which signal sending stations coexist, the time to detect the presence or absence of a signal in each time slot of a received frame signal. Slot monitor; monitors the time slot monitor output at all permissible transmission timings for each of the five time slots 1111 L, and determines whether the transmission timing is unused, used periodically, or non-periodically; and an access control circuit that transmits the aperiodic signal burst using a time slot other than the periodically used transmission timing. A periodic signal priority type random access transmitter.