JPS6342244A - Multiple address communication system - Google Patents

Abstract

PURPOSE:To decrease the capacity of a reverse direction transmission line, and to remarkably contrive the improvement of the utilization efficiency of a communication channel, by sharing a slot for sending out a retransmission request signal, by plural receiving stations. CONSTITUTION:Retransmission request signals corresponding to data bursts 1, 2,..., (n) on a forward transmission line are synchronized by the synchronization control circuit 35 of a receiving station 22 so as to be sent out to slots 1, 2,..., (n). Therefore, in a transmitting station, by only detecting the existence of the retransmission request signal, for instance, in the slot 1, it is known that said existence is requesting the retransmission of the data burst 1. Also, even if retransmission request signals are sent out almost simultaneously from plural receiving stations 22, and a collision occurs, it can be known that the retransmission is requested from at least one or more stations. In accordance with this retransmission request, the transmitting station executes the retransmission to a receiving station.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention provides a broadcast communication system that can efficiently utilize communication channels in an iM communication system in which the communication medium itself has a communication capability. 1. (Prior art) In the satellite communication system 6, there is a
′、′＼ wa、/L′ information iwo cho (・」、
The relevant i''n -ノ)~
Inside (: rizendenode,,':shin) i4 ni onecho:・
ㅅ” Believed, Ma #-C8 4. A, /CD (Capr
ier 5enqo Multipla Aeees
n wit,b Co11is-inn J',',)
ot, Cctior+) method, etc. LΔN(]f, ro
eal AλeaNcsemiyoyk) 1+ for the system
Even if it is, the sending J\mail from the end of the transmission is 1. Information I6d
:The power stored in the system concerned is 5 terminals of all 7 units, and the terminal station Oq, so it can be received from 1 to 3? -(OU-Uni, it's a system where the communication @ medium itself has circularity.'
7'T, multiple receiving stations from one transmitting M station...5, same...
When a message is transmitted = δ, the destination is a broadcast address with the receiving station as the destination, or a predetermined destination with the receiving station included in the group. By adding a group address to the message, it is possible to simultaneously deliver the message to multiple receiving stations.

However, in order to perform the error recovery of Metsu (-11~J, PETAGLI Showa Meso7~J), the receiving station must be the transmitting station... The direction communication channel is 8/)
. For example, in the Ail satellite communication system, a satellite line 1〆it#-number is assigned to each receiving station.
MuXtlpla Aeeonb) Tie A on the line
+' Assign slot 11: ,? It is necessary to physically allocate a third-class reverse direction communication path, and the LAN
In the :/ system, it was also necessary to logically allocate the reverse internal communication, such as sending retransmission request No. 01 to the transmitting station for each receiving station using the bucket transmission method. Unfortunately, with the conventional technology, it is not possible to increase the efficiency of communication channel use. A/N/Z: The weight of the 8 reverse internal channels in the entire system increases in proportion to the number of 8 receiving stations, and the disadvantage is that the efficiency of communication channel use is particularly low in systems with a large number of receiving stations. was there.

This invention improves the above-mentioned drawbacks of the conventional method.
The purpose of the present invention is to provide a broadcast communication system that uses a single communication channel with high efficiency.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a means for detecting errors in the information (Pl' signal) sent to the receiving station from the transmitting station, and a means for detecting errors in the iμ error. dl-, corresponding to the information signal 17. Determine the means for transmitting all retransmission request signals to the transmitting station on the backward transmission line & (h-fil) node commonly used by multiple receiving stations. 2. A means for detecting the presence or absence of a retransmission request signal on the reverse transmission path at the transmitting station, and a means activated by the detection of the presence of the signal to retransmit the information signal corresponding to the retransmission request signal. It is characterized by all the features 1 to ζ.

(Function) Errors in the 10H signal sent from the transmitting station to multiple receiving stations (error detection means of each receiving station) (Thus, detection 1.,,i
When iA error is detected, the retransmission request signal sending means of each receiving station transmits the signal to a slot determined on the reverse transmission path corresponding to the information signal and commonly used by a plurality of receiving stations. A retransmission request number M is sent to the station. Errors detected by multiple receiving stations for the same information signal 1 to fr,
In this case, multiple receiving stations will send retransmission requests (ff) to the same slot on the reverse transmission path at the same time, and these retransmission request signals will collide on the reverse transmission path. However, at the transmitting station, the means for detecting the presence or absence of a retransmission request signal fully detects whether at least one receiving station has transmitted a retransmission request signal, and if it is detected, information corresponding to the retransmission request signal is transmitted. Since the signal is retransmitted, even if retransmission request signals collide on the reverse transmission path, retransmission will be performed.

Therefore, according to the present invention, it is possible for a plurality of receiving stations to share a slot for transmitting a retransmission request signal,
Since there is no need to secure a reverse direction transmission path for sending retransmission request signals for each receiving station, it is possible to dramatically reduce the capacity of the reverse direction transmission path and greatly improve the overall communication path utilization efficiency. Become.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram of a broadcast communication system using a satellite as a first embodiment of the present invention. This system includes one transmitting station 21 and multiple receiving stations 22a, 22b.
, ..., 22n. The information signal to be broadcast from the transmitting station 21 to the plurality of receiving stations 22 a + 22 b *..., 22n is sent toward the communication satellite 23 as a signal having a frequency fl. This signal is frequency-converted by the communication satellite 23 and sent back to the ground as a signal having a frequency f1'.

This signal is received by a plurality of receiving stations 22a, 22b, . . . , 22n, respectively, within the antenna beam of the communication satellite 23. When each receiving station detects an error in the received information signal, it transmits a retransmission request signal to the transmitting station as a signal having a frequency fl. This signal is sent back to the ground as a signal having a frequency f2' by the communication satellite 23, and is received by the transmitting station 21. Here, the communication satellite 23 only converts the frequency f1 to f1' and fl to f2', fl+fl' constitutes a forward transmission path from the transmitting station to the receiving station, and f2+f2' from the receiving station to It can be seen that this constitutes a reverse transmission path to the transmitting station.

FIG. 1 is a diagram showing the structure of the transmitted and received signals in this embodiment. FIG.

The information signal to be broadcast outputted from the terminal device 11 of the transmitting station 21 is stored in the buffer memory 12 and inputted to the encoder 13, where it is encoded at the receiving station 22 so that error detection is possible. The encoded information signal is input to the burst transmitting/receiving circuit 14, and is input as a burst signal to the modulation/demodulation circuit 16 and modulated by a synchronization control signal from the synchronization control circuit 15. The modulated signal is converted into a signal having a transmission frequency f1 by a frequency conversion circuit 17, and is transmitted from an antenna 18 toward a communication satellite 23.

On the other hand, retransmission request signals of frequency fl / from the receiving stations 22a, 22b, -22n are sent to the antenna 18. Frequency conversion circuit 17, modulation/demodulation circuit 16. Retransmission request signal presence/absence detection circuit 19 received by burst transmission/reception circuit 14
The presence or absence of a retransmission request signal is detected.

, the presence detection signal of the retransmission request signal is sent to the buffer memory 12.
, and the corresponding information signal is retransmitted.

At the receiving station 22, the information signal of frequency f1' from the transmitting station 21 is transmitted through an antenna 31, a frequency conversion circuit 32,
It is received by the modulation/demodulation circuit 33 and the burst transmission/reception circuit 34. The burst transmitting/receiving circuit 34 outputs synchronization information of the received signal from the transmitting station, and inputs it to the synchronization control circuit 35. Also.

A coded information signal is also output from the burst transmitting/receiving circuit 34, inputted to the error detection circuit 36, decoded here, stored in the buffer memory 37, reconstructed as an information signal, and outputted to the terminal device 1t38. . Further, the error detection information is input to the retransmission request signal generation circuit 39, and the retransmission request signal generated here is input to the burst transmission/reception circuit 34. After the re) transmission request signal is input to the modulation/demodulation circuit 33 and modulated by the synchronization control signal of the synchronization control circuit 35,
The frequency conversion circuit 32 converts the signal into a signal with a frequency fl, and the antenna 31 sends the signal to the communication satellite.

FIG. 3 shows the relationship between the data e burst on the forward transmission path and the retransmission request f (no. *=
Figure 1. +1 direction transfer j6 bet ten data bar
1. Beto1゜2,...,n('t''::d"IS request (No. 4 + d, shudder) i, ;X ry,,
)1.2. -, n is sent once to j,' 6: Communication, n29's synchronous control circuit 35 (by which j1 is sent If the station detects the presence of a retransmission request signal for example 1λ, γ1, . , 1, Vr, Nari, Power] almost simultaneously from multiple receiving stations 22! fr, Output request message (J is exported tl-3 similar j
Even in the event of an emergency, it will be possible to send 14 from at least one station and make 7ti between the top and the bottom of the rice. In response to the (Kirin J Tsu request), the transmitting station sends a
2) Inversion will be performed.

Here, the form tΔ2 of the Yasugi signal, e.g.
If the information signal is changed (reduced) → (・'C vs. 2 [, unmodulated A signal, J= : f'1. If it is being transmitted and received as
, f, the numbers may be removed. The amount of time of the non-modulated signal may be randomly set.

This, il is times -・) (% Q'l -Qfj, J
4m '21.4 out'7) -<',=t)
At the ICC 10, multiple receiving stations 22 receive tλ1 simultaneously (
τ, the retransmission request signal is #h-7'r,s, that is, a collision has occurred.

and 11. “C41, on the transmitting station side, none; Kumo =
- Wire M feed F/2'i<183 No.183's 1,000' exit is hr, one end and the hole are'L-n-fi).

P) Transmission request A8 address/frequency; <C modulated signal (zu・toll
, Men'5) Name, Rani/Da, Nohei River f modulation
O”ru (two, and)) Tadayashi plan 1. < ,
, 1m j books ,↓,tsuC
・j3 Random 'JIS 6' is 1 degree per hole.

fsu sending J deficiency:〉((To Shinzuki, Ii, Sugi Hengen in ”f
(',: L〆4・, Pigeon house: +'C is also a random signal, change place", 12s W'-' h Hino [Call interval is random (previous setting, it is lξ child bite 1, 2 6, re'
J:! '＜ '9 $1. 'l(K'Q t
, IHm * wQ I? ) and jo, ノ';-to combination r ■ Modulate with a random signal, and set the amount of time to (2) Jin and one suggestion! ,i3. Random Kokan: Jyusurut, and (down, each receiving Ai 8 stations 22m, Heiko, Pe request (J-i 3.
-F3 was randomly established for 7 people and 122 receiving stations, and from then on the same -f! 1-) (+3 may be sent to M-transmission request A1, and the 7-point of the retransmission request signal indicates the receiving station 22 that sends the retransmission request signal. Information 5 For example, is the retransmission request satisfied in this system even if the address is not included?'
”, can be done.

As above, :! It becomes possible to share the slot for transmitting the retransmission request signal by W number of receiving stations, which dramatically reduces the capacity of the reverse transmission path and greatly improves the efficiency of communication path usage. It becomes possible.

FIG. 4 is a block diagram of the second embodiment of the present invention and the same F14 communication system on LANs 1 and 7. 43a
, 43b, . . . 943n are connected. Transmission interference body 4111'; j: A bidirectional transmission line, in which the information signal sent from the transmitting station 42 is transmitted to all receiving stations
: Ko,...

Received fl by 43n! '

Figure 5 is a diagram showing the configuration of the transmitter/receiver station according to this embodiment. Figure 5 (A) is a diagram showing the configuration of the transmitter station, and Figure 5 (B)
FIG. 2 is a diagram showing the configuration of a receiving station.

The broadcast information @ polarized code output from the terminal equipment ft 51 of the transmitting station 42 is stored in the buffer memory 52V (11). The encoded information signal is inputted to a bacut transmission circuit 54, and sent to a bus-like transmission medium 111 by a transmission buffer amplifier 55. On the other hand, the retransmission request signal from the receiving station 4 is sent to the receiving buffer amplifier 56 and the packet receiving circuit 5.
7, and is input to the retransmission request signal/presence detection circuit 58 to detect the presence or absence of the retransmission request signal. If retransmission occurs, it will be 1.

In the receiving station 43, the 1st good news IM 44 from the transmitting station 1 and 2 is received by the receiving buffer amplifier 61 and the packet receiving circuit 62. The received signal is input to the error detection circuit 63 (inputted here, decoded here and buffered) -
- It is stored in the memory G4 and output to the terminal block 1li5. , Error detection information 11 is generated by the retransmission request signal generation circuit 6 (5, ?7.?:), and is generated by the retransmission request signal generation circuit 6 (5). , transmission buffer amplifier 68 K, 1: is transmitted over the transmission medium 41.

FIG. 6 is a diagram showing a time chart of signals on the transmission medium 41 in an example of one-line switching. A certain period of time after the data φ burst is sent from the transmitting station is allocated as a slot for the receiving station to send a retransmission request signal Ig for the data burst. The transmitting station retransmits the data burst when the presence of a signal in the slot is detected, and transmits the next data burst when no signal is detected in the slot. . If multiple receiving stations send out retransmission request No. 15 at the same time, they will collide on the transmission path, but if, for example, the time length of the retransmission request signal is randomly varied, the presence or absence of the retransmission request signal can be detected easily. It becomes easier. Similar to the embodiment described above, in this embodiment as well, the data burst and the retransmission request signal transmission slot correspond to each other.・You can see that a burst retransmission is requested.

In this way, even in this embodiment, regardless of the number of receiving stations,
It is only necessary to leave the slot for sending out the retransmission request signal for one retransmission request signal, and the capacity of the reverse direction transmission path can be reduced by one order of magnitude, and the overall utilization efficiency of the communication path can be greatly increased. It becomes possible.

Although two embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to these embodiments, and that four modifications can be made without departing from the spirit of the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, in a broadcast communication system in which the communication medium itself has a broadcast property, it becomes possible for a plurality of receiving stations to share a slot for transmitting a retransmission request signal, and each Since there is no need to secure a reverse direction transmission path for sending retransmission request signals for each receiving station, it is possible to dramatically reduce the capacity of the reverse direction transmission path and greatly improve communication path utilization efficiency. .

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a transmitting and receiving station in the first embodiment of the invention, FIG. 2 is a system configuration diagram in the first embodiment of the invention, and FIG. 3 is a transmission diagram in the first embodiment of the invention. A diagram showing a time chart of signals on the road, FIG. 4 is a system configuration diagram in the second embodiment of the present invention, and FIG. 5 is a diagram showing the configuration of a transmitting and receiving station in the second embodiment of the present invention. is the time of the signal on the transmission path in the second embodiment of the present invention.
It is a figure which shows a chart. 11.38... Terminal device % 12.37... Buffer Φ memory, 13... Encoder, 36... Error detection circuit, 14.34... Burst transmission/reception circuit, 15.35
...Synchronization control circuit, 16.33...Modulation/demodulation circuit, 1
9...Retransmission request signal presence detection circuit, 39...Retransmission request signal generation circuit. Agent Patent Attorney Noriyuki Chika Yudo Kikuo Takehana / 2'9 Figure 2

Claims (13)

[Claims] (1) In a broadcast communication system in which information is transmitted from a single transmitting station to multiple receiving stations, the receiving stations include means for detecting errors in the information signal from the transmitting station, and are activated by the error detection; means for transmitting a retransmission request signal to a transmitting station in a slot determined on a backward transmission path corresponding to the information signal and commonly used by a plurality of receiving stations; A broadcast communication system comprising means for detecting the presence or absence of a retransmission request signal on the road, and means activated by the detection of the presence of the signal to retransmit an information signal corresponding to the retransmission request signal. . (2) The broadcast communication system according to claim 1, wherein the retransmission request signal is a non-modulated signal. (3) The broadcast communication system according to claim 2, wherein the unmodulated signal has a random frequency. (4) The broadcast communication system according to claim 2, wherein the unmodulated signal has a random time length. (5) The broadcast communication system according to claim 1, wherein the retransmission request signal is a frequency modulated signal. (6) The broadcast communication system according to claim 5, wherein the frequency modulated signal is a signal modulated with a random signal. (7) The broadcast communication system according to claim 5, wherein the frequency modulation signal has a random time length. (8) The broadcast communication system according to claim 1, wherein the retransmission request signal is a phase modulation signal. (9) The broadcast communication system according to claim 8, wherein the phase modulated signal is a signal modulated with a random signal. (10) The broadcast communication system according to claim 8, wherein the phase modulation signal has a random time length. (11) The broadcast communication system according to claim 1, wherein the retransmission request signal is an amplitude modulated signal. (12) The broadcast communication system according to claim 11, wherein the amplitude modulated signal is a signal modulated with a random signal. (13) The broadcast communication system according to claim 11, wherein the amplitude modulation signal has a random time length.