JPH09261266A - Service information communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the service information communication system inexpensively in which overflow and underflow for terminal equipments are avoided while avoiding waste of an incoming transmission channel. SOLUTION: A transmission rate information generating section 12 of a server 1 reads and decodes in advance service information to be sent to a base station 2A from an information storage section 11 to read transmission rate information included in the service information. A service information addition section 14 adds read transmission rate information to the service information to be sent to the base station 2A. An information separate section 22 of the base station 2A separates the transmission rate information from the service information received from the server and to which the transmission rate information in added. A transmission rate information storage section 23A reports the transmission rate information separated by the information separated section 22 to a transmission section 24 and controls the transmission section 24 so that the transmission rate of the service information to be delivered to a terminal equipment 3 is coincident with the transmission rate information to be reported.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a service information communication system such as a video on demand (VOD) system.

FIG. 10 is a block diagram showing the overall configuration of a conventional service information communication system. In FIG. 10, the service information communication system includes a server 100, a base station 200, and a terminal 300. A downlink transmission line 400a is provided from the server 100 to the base station 200, and an uplink transmission line 400b is provided from the base station 200 to the server 100. A downlink transmission line 500a is provided from the base station 200 to the terminal 300, and an uplink transmission line 500b is provided from the terminal 300 to the base station 200. The downstream and upstream transmission lines 400a and 400b are high speed (for example, 10
0 Mbps) transmission line, and downlink and upstream transmission lines 5
00a and 500b are low-speed (2 Mbps) transmission lines, and are formed symmetrically.

The server 100 holds encoded service information to be distributed to the terminal 300 via the base station 200. This service information includes image information, voice information, text information and the like. Further, this service information includes transmission rate information, and this transmission rate information is also encoded.

When service information is transmitted from the server 100 to the terminal 300, the server 100 uses the downlink transmission line 400.
The service information is transmitted to the base station 200 via a. The relay station 200 connects the server 100 via the downlink transmission path 500a.
The service information received from is delivered to the terminal 300 at a predetermined transmission rate, for example, 1.5 Mbps (see α in FIG. 11).

By the way, as shown in FIG. 11, the transmission rate of service information is, for example, 1.4 Mbps (β in FIG. 11).
1), 1.6 Mbps (see β2 in FIG. 11), 1.
For each program such as 2 Mbps (see β3 in FIG. 11),
It is different for each frame. The terminal 300 is the base station 20.
Service information received from 0 transmission rate 1.4 Mbp
s, 1.6 Mbps, 1.2 Mbps for decoding and reproduction. When there is a difference between the transmission rate of the service information transmitted from the base station 200 and the decoding reproduction speed of the terminal 300, an overflow or underflow occurs in the reception buffer provided inside the terminal 300.
Therefore, the terminal 300 judges the state of the reception buffer, and before the overflow or underflow occurs,
A transmission rate change request is transmitted to the base station 200 via the upstream transmission path 500b. The base station 200 that has received the transmission rate change request transmits the transmission rate change request to the server 100 via the upstream transmission path 400b. The server 100 that has received the transmission rate change request increases or decreases the transmission rate of the service information. As described above, in the conventional wireless mobile communication system, the terminal 30 is controlled by performing the flow control.
The occurrence of overflow or underflow in the receive buffer provided inside 0 is prevented.

[0006]

However, in the conventional service information communication system, the downlink transmission line 400a,
Since the upstream transmission path 400b and the upstream transmission path 500b, which are symmetrical to the downstream transmission path 500a, are used for flow control, there is a first problem that the upstream transmission path is wasteful.

Further, it is necessary to provide each server 100, base station 200, and terminal 300 with a high-speed transmission / reception unit for flow control, which makes a system of a service information communication system for distributing service information one to many expensive. There is a second problem.

As a method of solving these problems, it is conceivable that the upstream transmission path 400b and the upstream transmission path 500b are made to be low-speed or asymmetric transmission paths that have been eliminated, and the transmission / reception section for flow control is made low-speed or eliminated. If so, there is the following new problem.

That is, when the upstream transmission path 400b and the upstream transmission path 500b are low speed, the notification for flow control does not reach the server lately, so that overflow or underflow occurs in the terminal. Further, even when there is no upstream transmission line between the base station and the terminal, such as a broadcast type, the base station and the terminal cannot be notified, so that an overflow or underflow occurs in the terminal.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a service information communication system which eliminates waste of uplink transmission lines and is an inexpensive system, which avoids overflow and underflow at terminals.

[0011]

A service information communication system in which encoded service information is distributed from a service information distribution station to a terminal and the service information distributed by the terminal is decoded and reproduced. The distribution station reads the service information storage unit that stores the service information and the service information to be distributed to the terminal from the service information storage unit in advance, decodes and reproduces the service information, and the service information is included in the service information. , A transmission rate reading means for reading transmission rate information indicating an amount to be decoded and reproduced, an inter-terminal service information distributing means for distributing service information to be transmitted to the terminals, and a transmission rate information read by the transmission rate reading means for the terminal. Notify the inter-service information distribution means and convey the service information to be distributed to the terminals. Comprising a transmission rate control means and the transmission rate information notified and rate controls the service information distribution means between the terminals to match, the.

The service information distribution station includes a server and a base station, and the server adds the service information storage means, the transmission rate reading means, and the read transmission rate information to the service information to be transmitted to the base station. Including rate information adding means and inter-base station service information transmitting means for transmitting the service information to which the transmission rate information is added to the base station,
The base station includes an inter-terminal service information distribution means, a transmission rate control means, and a transmission rate information separation means for separating the transmission rate information for the transmission rate control means from the service information added with the transmission rate information received from the server. , Can also be included.

The base station further includes actual transmission rate measuring means for measuring the actual transmission rate of the service information distributed by the inter-terminal service information distributing means to the terminals, and the transmission rate control means measures the actual transmission rate measuring means. It is also possible to notify the actual transmission rate and control the inter-terminal service information distribution means so as to eliminate the error between the actual transmission rate and the transmission rate information.

The actual transmission rate measuring means includes first period transmission rate measuring means for measuring the actual transmission rate in the first period,
Second period transmission rate measuring means for measuring an actual transmission rate in a second period longer than the first period, and the transmission rate control means notifies the actual transmission rate measured by the first period transmission rate measuring means. , The inter-terminal service information distribution means is controlled so that the error between the actual transmission rate and the transmission rate information is eliminated, and the actual transmission rate measured by the second period transmission rate measuring means is notified, and the actual transmission rate and the transmission rate information are notified. It is also possible to control the inter-terminal service information distribution means so that there is no difference between

[0015]

1 is a block diagram showing an example of the overall configuration of a service information communication system according to a first embodiment of the present invention. 1, the service information communication system includes a server 1, a base station 2A, and a terminal 3. A transmission line 4 is provided from the server 1 to the base station 2A. A transmission line 5 is provided from the base station 2A to the terminal 3. The transmission path 4 is a wired or wireless high speed (for example, 100 Mbp).
s) transmission line. The transmission line 5 is formed of a wired or wireless low-speed (for example, 2 Mbps) transmission line. Further, in this service information communication system, no upstream transmission line for flow control is provided. The server 1 and the base station 2B are the service information distribution station 6
A is formed.

The server 1 holds encoded service information to be distributed to the terminal 3 via the base station 2A. This service information includes image information, voice information, text information and the like. Further, this service information includes transmission rate information, and this transmission rate information is also encoded.

When transmitting service information from the server 1 to the terminal 3, the server 1 transmits the service information to the base station 2 via the transmission path 4. The base station 2A delivers the service information received from the server 1 via the transmission path 5 to the terminal 3 at a predetermined transmission rate.

FIG. 2 is a block diagram showing an example of a concrete configuration of the server 1 shown in FIG. In FIG. 2, the server 1
Is an information storage unit 11, a transmission rate information generation unit 12,
Transmission rate information storage unit 13 and service information addition unit 14
And a server-to-base-station transmitting unit 15.

The information storage unit 11 includes a storage unit such as a hard disk and a memory, and stores service information such as video information, text information, and audio information in this storage unit.
This service information is encoded such as MPEG, and its data amount is compressed. Also, for each frame of service information, transmission rate information indicating the amount by which the terminal 3 should decode and reproduce the service information is recorded per unit time, and this transmission rate information is also encoded. Therefore, the transmission rate information cannot be directly seen unless the service information is decoded.

The transmission rate information generation unit 12 includes, for example, an encoder, and when transmitting the service information stored in the information storage unit 11, reads and decodes the service information stored in the information storage unit 11, and the service information Read out the transmission rate required for decoding and playback of. This is because the transmission rate information is also decoded, so that the service information needs to be decoded in order to see the transmission rate information.

The transmission rate information storage unit 13 includes a storage unit such as a memory, and the transmission rate information generation unit 12 is included in this storage unit.
The transmission rate information read by is stored. The service information addition unit 14 visually adds the transmission rate information to the service information transmitted to the base station 2A. Specifically, for example, the transmission rate information is stored in the header of the frame storing the service information. Alternatively, only the transmission rate information may be sent to the base station 2A in advance. The inter-server / base-station transmitting unit 15 is composed of, for example, an I / F circuit or the like, and transmits the service information generated by the service information adding unit 14 to the base station 2A.

FIG. 3 is a block diagram showing an example of a concrete configuration of the base station 2A shown in FIG. In FIG. 3, the base station 2
A is an inter-server / base-station receiving unit 21 and an information separating unit 22.
And a transmission rate information storage unit 23A and a transmission unit 24.

The inter-server / base-station receiving unit 21 is, for example, I
/ F circuit, etc., and receives service information from the server 1. Transmission rate information is added to this service information. The information separation unit 22 is composed of, for example, a header detection circuit or the like, and separates the service information received by the inter-server-base-station reception unit 21 into service information and transmission rate information. The transmission rate information storage unit 23A includes a storage unit such as a memory, stores the separated transmission rate information, and notifies the transmission unit 24 of this transmission rate information. The transmission unit 24 transmits the service information separated by the information separation unit 22 to the terminal 3 according to the transmission rate information notified from the transmission rate information storage unit 23A.

FIG. 4 is a block diagram showing an example of a concrete configuration of the terminal 3 shown in FIG. In FIG. 4, the terminal 3 includes a receiving unit 31, an information storage unit 32, and an information reproducing unit 33.

The receiving unit 31 is composed of, for example, an I / F circuit or the like, and receives the service information transmitted from the base station 2A. The information storage unit 32 is composed of, for example, a FIFO buffer, and stores the service information received by the reception unit 31. The information reproduction unit 33 includes, for example, a decoder and an audio / image reproduction unit, and decodes and reproduces the service information stored in the information storage unit 32 at the transmission rate.

Operation Next, the operation of the service information communication system shown in FIGS. 1 to 4 will be described. When the service information is transmitted from the server 1 to the terminal 3, the transmission rate information generation unit 12 of the server 1 reads the service information (see FIG. 5A) stored in the information storage unit 11 and decodes and reproduces it to obtain the transmission rate. Is read (see FIG. 5B), and the read transmission rate information is stored in the transmission rate information storage unit 13. The service information addition unit 14 adds transmission rate information to the service information (see FIG. 5).
(See (c)), the inter-server-base-station transmitting unit 15 transmits the service information to which the transmission rate information is added.

When the inter-server / base-station receiving unit 21 of the base station 2A receives the service information to which the transmission rate information is added, the information separating unit 22 separates the service information and the transmission rate information (see FIG. 5 (d)). ), The transmission unit 24 transmits the service information at a transmission rate according to the separated transmission rate information.

By the way, as shown in FIG. 6, the transmission rate of the service information is, for example, 1.4 Mbps (see β1 in FIG. 6), 1.6 Mbps (see β2 in FIG. 6), 1.2 Mb.
ps (see β3 in FIG. 6) and the like, which are different for each program and each frame. In this case, the transmitter 24 transmits the transmission rates 1.4 Mbps and 1.6 according to the separated transmission rate information.
The service information is transmitted at Mbps and 1.2 Mbps, respectively.

Next, when the receiving unit 31 of the terminal 3 receives the service information, the information storage unit 32 temporarily stores this service information, and the information reproducing unit 33 stores the service information stored in the information storage unit 32. Transmission rate 1.4 Mbps,
Decode and reproduce at 1.6 Mbps and 1.2 Mbps.

Therefore, according to the wireless mobile communication system of the first embodiment, the server 1 accumulates the transmission rate information of the service information, adds the transmission rate information to the service information, and transmits the service information. Since the service information is distributed from the base station 2B at the transmission rate for decoding and reproduction, it is possible to prevent the occurrence of overflow or underflow at the terminal. As a result, it is not necessary to provide a symmetrical upstream transmission line as in the conventional case, and waste of the upstream transmission line can be prevented. Further, unlike the conventional case, it is not necessary to provide each server, base station, and terminal with a transmission / reception unit for flow control, so that each server, base station, and terminal can be formed inexpensively, and the system can be made inexpensive. Further, since the server reads the service information to be transmitted to the base station in advance, decodes and reproduces it, and reads the transmission rate information included in the service information, the system is cheaper than the decoder provided in each base station. be able to.

FIG. 7 is a block diagram showing an example of the overall configuration of a wireless mobile communication system according to the second embodiment of the present invention, and FIG. 8 is a diagram showing an example of a specific configuration of the base station 2B of FIG. Is. The parts corresponding to those of the wireless mobile communication system of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the communication system of FIG. 7, the base station 2B of the service information distribution station 6B is used in place of the base station 2A of the service information distribution station 6A of FIG. The base station 2B is
It includes an inter-server-base-station receiving unit 21, an information separating unit 22, and an actual transmission rate measuring unit 25. Actual transmission rate measuring unit 25
Includes a short cycle measuring unit 25a and a long cycle measuring unit 25b. Further, the transmission rate information storage unit 23B is used instead of the transmission rate information storage unit 23A. Also, the transmitter 2
The transmitter 24B is used in place of 4A.

The transmission rate information storage section 23B stores the separated transmission rate information. The transmitter 24B transmits the service information separated by the information separator 22 at a rate according to the transmission rate information. Actual transmission rate measurement unit 2
5 measures the actual transmission rate of the transmitter 24B.

The base station 2B which has received the service information by the inter-server base station receiving unit 21 separates the service information and the transmission rate information by the information separating unit 22 and transmits the service information by the transmitting unit 24B according to the separated transmission rate. Send. Then, the actual transmission rate measuring unit 25a measures the transmission rate transmitted from the transmitting unit 24B in a short period (for example, 1 second), and the actual transmission rate measuring unit 25b transmits the transmission rate from the transmitting unit 24B. Rate over a long period (eg 1
And the transmission rate information storage unit 23B determines the difference between the transmission rate of the service information and the actual transmission rate.
4B, and the transmission unit 24B controls the actual transmission rate so that the actual transmission rate matches the transmission rate information. This occurs due to the timing shift of the frame transmission of the transmitter 24 and the fluctuation of the clock. In this case, if this is left as it is, there is a possibility that overflow or underflow may occur in the terminal.

Therefore, the actual transmission rate measuring unit 25a is
The actual transmission rate is measured every one second, and the actual transmission rate is notified to the transmission rate information storage unit 23B. The transmission rate information storage unit 23B notifies the transmission unit 24 of this. Transmitter 24
Even if slight errors δ1 to δ4 (see FIG. 9A) occur, the actual transmission rate is set to the transmission rate (for example, 1.5M).
bps). However, this control may cause overflow or underflow at the terminal due to the accumulation of slight errors δ1 to δ4. Therefore, the actual transmission rate measuring unit 25b measures the actual transmission rate every one minute, and the actual transmission rate is stored in the transmission rate information storage unit 23.
Notify B. The transmission rate information storage unit 23B notifies the transmission unit 24 of the difference between the actual transmission rate and the target transmission rate. The transmission unit 24 accumulates these errors δ1 to δ4,
The actual transmission rate is controlled to eliminate the error (Fig. 9).
(B)).

As described above, according to the wireless mobile communication system of the second embodiment, even if there is an error between the actual transmission rate and the transmission rate information, the overflow or underflow at the terminal can be accurately and reliably performed. It is possible to prevent the generation of flow. Further, the terminal 3 can reduce the reception buffer management. Further, the service information can be distributed without delay from the terminal without transmitting the transmission rate change request.

[0037]

According to the present invention, the service information to be distributed to the terminal is read out in advance from the service information storage means, decoded and reproduced, is included in the service information, and the terminal decodes and reproduces the service information per unit time. The transmission rate information indicating the power amount is read, the transmission rate information read by the transmission rate reading means is notified to the inter-terminal service information distribution means, and the transmission rate of the service information to be distributed to the terminals and the notified transmission rate information are Since the inter-terminal service information distribution means is controlled so that they match, the service information is distributed at the transmission rate at which the terminals decode and reproduce,
It is possible to prevent the occurrence of overflow or underflow in the terminal, and it is not necessary to provide a symmetrical upstream transmission line as in the conventional case, and it is possible to prevent waste of the upstream transmission line. Further, unlike the conventional case, it is not necessary to provide each server, base station, and terminal with a transmission / reception unit for flow control, and the service information distribution station and terminal can be inexpensively formed, and the system can be inexpensive.

Further, since the server reads the service information to be transmitted to the base station in advance, decodes and reproduces it, and reads the transmission rate information included in the service information, the service information for distributing the service information one to many. Even if the number of base stations is large as in a communication system, it is not necessary to provide a decoder in each base station, and the system can be made cheaper than providing a decoder in each base station.

In the base station, the inter-terminal service information distribution means measures the actual transmission rate of the service information distributed to the terminals, the actual transmission rate measurement means notifies the measured actual transmission rate, and the actual transmission rate and the transmission rate information are reported. Since the terminal-to-terminal service information distribution means is controlled so as to eliminate the error between the terminals, even if there is an error between the actual transmission rate and the transmission rate information, the occurrence of overflow or underflow at the terminal is surely prevented. be able to. Further, the reception buffer management at the terminal can be reduced. Further, the service information can be distributed with a reduced delay without transmitting a transmission rate change request from the terminal.

The first transmission rate measuring means for measuring the actual transmission rate in the first cycle by the actual transmission rate measuring means and the second cycle transmission for measuring the actual transmission rate in the second cycle longer than the first cycle. Rate measuring means, notifying the actual transmission rate measured by the first period transmission rate measuring means, controlling the inter-terminal service information distributing means so as to eliminate an error between the actual transmission rate and the transmission rate information, and Notify the actual transmission rate measured by the two-cycle transmission rate measuring means,
Since the terminal-to-terminal service information distribution means is controlled so that the error between the actual transmission rate and the transmission rate information is eliminated, even if there is an error between the actual transmission rate and the transmission rate information, the terminal can be more accurately and surely. It is possible to prevent the occurrence of overflow or underflow in the.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of an overall configuration of a service information communication system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an example of a specific configuration of a server 1 of FIG.

3 is a block diagram showing an example of a specific configuration of a base station 2A of FIG.

4 is a block diagram showing an example of a specific configuration of a terminal 3 of FIG.

FIG. 5 is a diagram showing operations such as reading and adding transmission rate information.

FIG. 6 is a diagram showing a relationship between transmission rate information of service information and an actual transmission rate.

FIG. 7 is a block diagram showing an example of an overall configuration of a wireless mobile communication system according to a second exemplary embodiment of the present invention.

FIG. 8 is a diagram showing an example of a specific configuration of a base station 2B of FIG.

FIG. 9 is a diagram showing a relationship between a transmission rate and an actual transmission rate.

FIG. 10 is a block diagram showing an overall configuration of a conventional service information communication system.

FIG. 11 is a diagram showing a relationship between a conventional transmission rate and flow control.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Server 2A, 2B ... Base station 3 ... Terminal 6A, 6B ... Service information distribution station 11 ... Information storage part 12 ... Transmission rate information generation part 13 ... Transmission rate information storage part 14 ... Service information addition part 15 ... Server base station Inter-transmission unit 21 ... server inter-base station reception unit 22 ... information separation unit 23A, 23B ... transmission rate information storage unit 24 ... transmission unit 25 ... actual transmission rate measurement unit 25a ... short cycle measurement unit 25b ... long cycle measurement unit 31 ... Receiving unit 32 ... Information storing unit 33 ... Information reproducing unit

Claims (4)

[Claims] 1. A service information communication system in which encoded service information is distributed from a service information distribution station to a terminal, and the service information distributed in the terminal is decoded and reproduced, wherein the service information distribution station A service information storage unit that stores the service information; and a service information storage unit that reads the service information to be distributed to the terminal from the service information storage unit in advance and decodes and reproduces the service information. Transmission rate reading means for reading transmission rate information indicating the amount of information to be decoded and reproduced, inter-terminal service information distributing means for distributing service information to be transmitted to the terminal, and transmission rate read by the transmission rate reading means. The information is notified to the inter-terminal service information distribution means and distributed to the terminals. Service information communication system comprising a transmission rate control means and the transmission rate information notified with the transmission rate of the should do service information for controlling the inter-terminal service information delivery means to match, the. 2. The service information distribution station includes a server and a base station, and the server transmits the service information storage means, the transmission rate reading means, and the read transmission rate information to the base station. Transmission rate information adding means for adding the service information to the base station, and the inter-base station service information transmitting means for transmitting the service information to which the transmission rate information is added to the base station. An information distribution unit, the transmission rate control unit, and a transmission rate information separation unit that separates the transmission rate information for the transmission rate control unit from the service information added with the transmission rate information received from the server. The service information communication system according to claim 1. 3. The base station further includes actual transmission rate measuring means for measuring an actual transmission rate of service information distributed by the inter-terminal service information distributing means to the terminals, and the transmission rate control means includes the actual transmission rate. 3. The service according to claim 2, wherein the rate measurement means notifies the measured actual transmission rate, and controls the inter-terminal service information distribution means so that an error between the actual transmission rate and the transmission rate information is eliminated. Information and communication system. 4. The actual transmission rate measuring means measures first actual transmission rate in a first cycle, and first actual transmission rate in a second cycle longer than the first cycle. And a second period transmission rate measuring unit for transmitting the actual transmission rate measured by the first period transmission rate measuring unit so that an error between the actual transmission rate and the transmission rate information is eliminated. Controlling the inter-terminal service information distribution means, notifying the actual transmission rate measured by the second period transmission rate measuring means, and eliminating the error between the actual transmission rate and the transmission rate information. The service information communication system according to claim 3, wherein the distribution means is controlled.