JPH05316007A - Composite satellite channel multiplexing system - Google Patents

Abstract

PURPOSE:To save a frequency resource by sending control information through the use of a channel of a packet data area in a star satellite communication network in which one master station and plural slave stations are employed for duplex communication. CONSTITUTION:A time base on a satellite channel is divided into two areas as a packet data area and a stream data area, the communication by the random access system is implemented in the packet data area, and stream data are communicated by using a variable length burst in matching data speed. Furthermore, the stream data area is allocated by each slave station through the use of the packet data area and the transmission of an allocation request 12 and the master station implement allocation processing 18 based thereon.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiplex satellite channel multiplexing system, and more particularly, it uses the same stream type data and packet type data between one master station and a slave station for bidirectional communication. In a star-type satellite communication network system that transmits using channels, control information that allocates the frequency to be transmitted from the master station to the earth station of the slave station is used for packet transmission control of stream-type data without using the control channel. The present invention relates to a complex satellite line multiplexing method for transmitting data using the data area of the above.

[0002]

2. Description of the Related Art As shown in FIG. 4A, a satellite communication network system in a conventional multi-satellite channel multiplexing system transmits packet data and stream data as data signals to a master station and a slave station via a satellite 25. When communicating with each other, first, as in the DAMA method or the like, the master station needs to specify the allocation of frequencies to be transmitted to the slave stations and configure the satellite circuit. That is, the master station inputs the control channel signal, which is the frequency allocation information of the slave station, from the transmission frequency allocation signal generator 21 to the multiplexer 22. As shown in FIG. 4B, the multiplexer 22 requires a control signal channel in addition to the data transmission channels for packet data and stream data. The multiplexing system of the multiplexing device 22 includes a stream data satellite communication device 23, a satellite transmission / reception unit 24, a slave station transmission / reception unit 26 via a satellite 25, a stream data satellite communication device 27, and a multiplexing device 27. Then, the transmission frequency allocation signal detection / control unit 29 detects the control channel signal. With this allocation information, the transmission frequency for stream data of the slave station is set, and mutual communication of stream data is started.

Next, in order to carry out the communication by mixing the packet type data and the stream type data together, the multiplexers 22 and 28 are connected to the communication devices 23 and 27 for stream data, and the multiplexers 22 and 28 are connected. The stream data and packet type data are multiplexed by 23, and communication is performed on the satellite line by the stream data access method. That is,
As the satellite line multiplexing method, a multiplexing method for stream data will be used. Therefore, an independent channel is required for multiplexing control.

[0004]

This conventional composite satellite line multiplexing system requires another control channel frequency in addition to the original data transmission channel for satellite line multiplexing. Therefore, there is a drawback that frequency resources are consumed further. In addition to the satellite communication device, an external multiplexing device is required, which increases the cost of the device.

[0005]

According to the satellite line multiplexing system of the present invention, a master station and a plurality of slave stations communicating with each other are provided.
In a complex satellite circuit multiplexing system that performs bidirectional communication of packet data and stream data by two channels, a channel for master station transmission and a channel for slave station transmission,
At least each frame of the transmission channel from the slave station to the master station is divided into two parts, a packet data area and a stream data area, and in the packet data area, the control information for stream data area allocation uses the idle time of packet data transmission. Do it.

[0006]

The present invention will be described below with reference to the drawings. FIG. 1 is a frame configuration diagram of a satellite line according to an embodiment of the present invention. In FIG. 1, in the master station transmission channel, in addition to user data (stream data, packet data) on a continuous signal, a frame synchronization signal of the slave station transmission channel and stream data area allocation information are transmitted to the slave station in a broadcast mode. Control information 10 is transmitted at a frame cycle. In the slave station transmission channel, in n frames in FIG. 1, station A and station B are transmitting stream data 11 of station A and station B in a burst length matching the respective data rates in the stream data area. In the data area, station C and station D transmit packet data 12 and 13 of station C and station D by random access. Here, the data packet 12 of the station C is the data of the stream data area allocation request, and the stream data area allocation is requested by transmitting this to the master station. The master station that has received this allocation request packet 12 performs the stream data area allocation processing 17 shown by the broken line in FIG. 1 and puts the stream data area allocation information 18 on all the slave stations in the control information 10 of the master station transmission channel. Then, each slave station allocates the stream data area based on this information. In the example of FIG. 1, the allocation request 12
The station C that has transmitted is to acquire the allocation of the stream data area and transmits the stream data 15 from the n + 2 frame. Further, when the transmission of the stream data is ended, the transmission end information is added to the last burst of the stream data, and the master station having received the information performs the deallocation / re-allocation processing of the stream data area. This processing is the area (minislot) that has been used until now for stream data transmission.
And the allocation of the burst using the minislot after the released minislot is shifted forward by the released area. For example, in FIG. 1, when the station A transmits the last burst 14 of stream data, the transmission completion information is added to this burst and the burst data is transmitted to the master station. The master station performs the stream data area de-allocation processing 19 shown by the broken line in FIG. 1, and performs an allocation (16 in FIG. 1) in which the allocation areas of station B and station C that were used after the area of station A are shifted to the front. To do.

Next, the embodiment of FIG. 2 is a block diagram showing the configuration of the master station. In FIG. 2, when transmitting packet data, the packet data transmission interface unit 201 interfaces with the outside of the station, and then the packet data transmission control unit 202 performs link control on the satellite line to perform TDM. The transmission processing unit 205 multiplexes and transmits. When transmitting stream data, first, the stream data transmission interface unit 203
Then, the stream data area allocation request 231 for calling the master station is sent to the stream data area allocation processing unit 211. The stream data area allocation processing unit 211 allocates the stream data area based on this, transmits the allocation information on the control information (control information 10 in FIG. 1) to all the slave stations, and when this allocation is completed, The stream data is transmitted via the stream data compression buffer 204, the TDM transmission processing unit 205 and the modulator. The data reception process in the master station is first divided into packet data and stream data by the TDMA reception processing unit 225, and the packet data is subjected to satellite line link control by the packet data reception processing unit 222 and externally by the packet data reception interface unit 221. The data is sent to the outside through the interface with the stream data, and the stream data is sent to the outside via the stream data receiving interface unit 223 in the stream data expansion buffer 224 according to the data rate with the outside. Further, when the stream data area allocation request (allocation request 12 in FIG. 1) included in the packet data is received, the allocation request 232 received by the packet data reception processing unit 222 is sent to the stream data area allocation processing unit 211, and the The data area allocation processing unit 211 allocates the stream data area based on this, and transmits the allocation information to all the slave stations by placing the allocation information on the control information (control information 10 in FIG. 1). It should be noted that the transmission timing in the master station is the transmission frame timing 2 by the frame timing generator 212.
33 is transmitted to the TDM transmission control unit 205, and the reception timing is set to the frame timing generator 2.
It is established by sending the timing obtained by delaying the transmission frame timing 233 by a constant offset value by 12 as the reception frame timing 234 to the TDMA reception processing unit 225.

Next, FIG. 3 is a block diagram of a slave station in the present invention. In FIG. 3, packet data transmission is performed in the same manner as the master station by the packet data transmission interface unit 301.
And TDM via the packet data transmission control unit 302
The A transmission processing 305 is multiplexed and transmitted. For the transmission of stream data, first, when a transmission request is generated, the stream data transmission interface unit 303 creates a stream data area allocation request 331, and the stream data transmission interface unit 303 and the TDMA transmission control unit 305 send it to the master station. After being transmitted and the stream data area is acquired by the allocation process in the master station, the stream data transmission interface unit 303 and the stream data compression buffer 30
The data is multiplexed and transmitted by the TDMA transmission control unit 305 via No. 4. First, the data reception process in the slave station is performed by TD.
Control information 332 including frame timing information and stream data area allocation information in the M reception control unit 325
(Control information 10 in FIG. 1), packet data and stream data are divided, and control information 332 is sent to the TDMA transmission processing unit 305 and used for transmission control of packet data and stream data. The packet data is the same as the master station. Then, the data is sent to the outside via the packet data reception control unit 322 and the packet data reception interface unit 321. Similarly, the stream data is also sent to the outside via the stream data expansion buffer 324 and the stream data reception interface unit 323. The TDMA transmission timing of the slave station is obtained by delaying the frame timing in the control information 332 received from the master station by a certain offset value.

[0009]

As described above, according to the present invention, the time axis is divided into an area for packet data and an area for stream data, so that the stream can be streamed without any multiplexer as in the prior art. It is possible to transmit both the type data and the packet type data on the same channel by the time division multiple access method. Furthermore, by transmitting control information for allocating the stream data area using the packet data area,
Since it is not necessary to use another channel (frequency) for allocating the stream data area as in the conventional example, there is an effect that frequency resources can be saved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a signal format according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a master station of this embodiment.

FIG. 3 is a block diagram showing a configuration of a slave station according to the present embodiment.

FIG. 4 is a configuration diagram (a) of a conventional multiple satellite communication line multiplexing system and a frequency allocation diagram (b) of a data transmission channel and a control signal.

[Explanation of symbols]

11, 14, 15, 16 Stream data burst 12, 13 Packet data burst (12 includes stream data area allocation request) 17 Stream data area allocation processing 18 Stream data area allocation information 19 Stream data area de-allocation processing 201 packets Data transmission interface unit 202 Packet data transmission control unit 203 Stream data transmission interface unit 204 Stream data compression buffer 205 TDM transmission control unit 211 Stream data area allocation processing unit 212 Frame timing generator 221 Packet data reception interface unit 222 Packet data reception control unit 223 Stream data reception interface unit 224 Stream data expansion buffer 225 TDMA reception control unit 231 Origin of master station Stream data area allocation request 232 Stream data for call from slave station 233 Transmission frame timing 234 Reception frame timing 301 Packet data transmission interface unit 302 Packet data transmission control unit 303 Stream data transmission interface unit 304 Stream data compression buffer 305 TDMA transmission control unit 321 Packet data reception interface unit 322 Packet data reception control unit 323 Stream data reception interface unit 324 Stream data expansion buffer 325 TDM reception control unit 331 Stream data area allocation request 332 Control information

Claims (2)

[Claims] 1. Two-way communication of packet data and stream data is performed between a plurality of slave stations communicating with one master station by two channels, a master station transmission channel and a slave station transmission channel. In the multiplex satellite channel multiplexing system to be performed, at least each frame of the transmission channel from the slave station to the master station is divided into two parts, a packet data area and a stream data area, and control information for stream data area allocation is provided in the packet data area. A multiplex satellite communication line multiplexing method characterized in that the idle time of packet data transmission is used. 2. When performing bidirectional communication of packet data and stream data between a master station and a plurality of slave stations,
In the master station transmission channel, control information from the master station to the slave stations and user packet data and stream data are time-division multiplexed on a continuous signal and transmitted in broadcast mode. The stream data area is divided into a stream data area and a packet data area, the stream data area is further divided into a plurality of minislots for time division multiplexing, and the packet data area is also a stream data area for time division multiplexing. It has a time axis structure in which it is divided into slots of independent sizes, and these are combined into one control unit frame. In the stream data area, the size of the data burst is used to flow multiple data streams of different speeds. Variable and transmit at any timing of the minislot, and random access in the packet data area. Each slave station transmits fixed-length packet data, and the control information for stream data area allocation is transmitted using the packet data area of the master station transmission channel, so that the stream data area allocation can be changed in real time. A complex satellite line multiplexing method characterized by.