JPH11146014A - Distribution multimedia server device, method for accessing distribution multimedia server information and recording medium recording program to realize the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a distribution multimedia server device that requires no synchronization with other server module with an excellent operating efficiency of a terminal side network and to realize the access method that copses flexibly with the case that number of connection terminals is increased, a storage server module or a storage device is extended with less deterioration in the performance. SOLUTION: The device is provided with a plurality of communication server modules 311-31M that conduct communication with terminals, a plurality of storage server modules 321-332N that store multimedia information, and an inter-server-module network 33 that attains communication between an optional communication server module and an optional storage server module. The communication server modules 311-31M connection to an object terminal making multimedia information distribution and deliver sequentially a segment of a plurality of multimedia information sets transferred from a plurality of the storage server modules via the inter-server-module network 33 so as to avoid interruption of reproduction by a terminal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distributed multimedia system for delivering multimedia information to each terminal or storing multimedia information from a multimedia information input device to a multimedia server in response to requests from a large number of terminals. The present invention relates to a media server device, a distributed multimedia server information access method, and a recording medium storing a program for implementing the method.

[0002]

2. Description of the Related Art Conventionally, a service for delivering multimedia information to each terminal has been realized by a single multimedia server device.

FIG. 13 shows a block diagram of a conventional single multimedia server device. A communication control unit 911 communicates with the terminal, a central control unit 912 controls the entire multimedia server device, a storage unit 913 temporarily stores multimedia information and the like at the time of delivery to the terminal, and a storage unit 91.
5 stores multimedia information, and stores the system bus 914
Is a communication control unit 911, a central control unit 912, a storage unit 91
3. Data transfer between the storage units 915 is performed.

In the case of a single multimedia server device as shown in FIG. 13, the maximum number of simultaneously connected terminals is limited by the transfer bottleneck of the system bus 914 and the input / output speed bottleneck of the storage unit 915. Therefore, it has been considered to increase the maximum number of simultaneously connected terminals by a distributed multimedia server device in which a plurality of server modules are connected via a network.

FIG. 14 is a block diagram showing a configuration of a system using a conventional distributed multimedia server device. The terminals 211 to 21L make a multimedia information read request to the distributed multimedia server device 23 via the terminal side network 22, and reproduce the received multimedia information. The terminal side network 22 is a terminal 2
It is a network that connects the distributed multimedia server devices 23 to 11 to 21L.

[0006] The distributed multimedia server device 23 includes server modules 2311 to 231M for delivering multimedia information to the terminal, and a control module 232 for receiving a request from the terminal and sending a multimedia information delivery request to the server module. Consists of

[0007] One piece of multimedia information is divided into fixed-length multimedia blocks (segments) and distributed and stored in a plurality of server modules 2311 to 231M. The configuration of each of the server modules 2311 to 231M is the same as that shown in FIG. 13, and each server module can operate as a single multimedia server device. Delivery of multimedia information using this distributed multimedia server device is performed as follows.

(1) A request for reading multimedia information including a program identifier to be read is transmitted from the terminal 21 i to the control module 232 via the terminal side network 22.

(2) A multimedia information delivery request is transmitted from the control module 232 to all the server modules 2311 to 231M via the terminal side network 22.

(3) Server modules 2311 to 231
M synchronizes the segments of the multimedia information distributed and stored in each server module with the terminal side network 22 while synchronizing with the other server modules so that the terminal does not receive the multimedia information from a plurality of server modules at the same time. It is delivered to the terminal 21i via the terminal 21i.

(4) Similarly, multimedia information is simultaneously delivered to a plurality of terminals. That is, some server modules may have different delivery destination terminals for each segment.

[0012]

However, the conventional distributed multimedia server apparatus has the following problems. (1) It is necessary to synchronize with another server module so that the terminal does not receive multimedia information from a plurality of server modules at the same time.

(2) The server module delivers multimedia information to different terminals in order. If the terminal side network 22 is of a connectionless type, the multimedia information is delivered to the terminal as scheduled due to a collision in the network. The playback may be interrupted at the terminal. On the other hand, if the terminal side network 22 is connection-type, it is necessary that one server module hold connections with all terminals or repeat disconnection and connection with terminals at short time intervals called multimedia block delivery time. There is. In the former case, it is necessary to hold the connection even when multimedia information delivery is not performed. In the latter case, the connection disconnection and connection processing are overhead, and the effective connection time for multimedia information delivery is possible. , And the use efficiency of the terminal side network 22 is low in any case.

(3) In addition to the server modules 2311 to 231M for delivering multimedia information, a control module 232 for centrally controlling the entire distributed multimedia server device 23 is required.

(4) The terminal side network 22 or the terminals 211 to 21L and the distributed multimedia server device 23
When the communication protocol between them is changed, the effect is exerted on all the server modules 2311 to 231M.

An object of the present invention is to provide a distributed multimedia server device which does not require synchronization with other server modules and has a high use efficiency of the terminal side network 22. Furthermore, a distributed multimedia server information access method that can flexibly cope with the increase in the number of connected terminals or the number of storage server modules in a distributed multimedia server device or the number of storage devices is increased, with less performance degradation. To provide.

[0017]

SUMMARY OF THE INVENTION The present invention is a multimedia server device for delivering continuous multimedia information, such as video information and audio information, requested by a plurality of terminals to each terminal. A communication server module for communicating with a terminal, a storage server module for storing multimedia information, and a network between server modules for enabling communication between any communication server module and the storage server module. Features.

Further, according to the present invention, each storage server module accesses a segment of its own storage server module independently of an access process to a segment by another storage server module. It manages the segment delivery timing to the terminal, and issues a read request to the storage server module specifying the segment to be read.

According to the present invention, the communication server module holds a connection with a target terminal for delivering multimedia information, and stores a plurality of multimedia blocks (from the plurality of storage server modules via the network between the server modules). Segments) are delivered in order so as not to cause interruption in reproduction at the terminal, so that synchronization with other server modules is not required, and the use efficiency of the terminal side network is good.

The program for causing the computers of the communication server module and the storage server module to execute the above processing is a computer-readable portable medium memory,
It can be stored in an appropriate recording medium such as a semiconductor memory or a hard disk.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention. First, an outline of a distributed multimedia server device according to the present embodiment will be described with reference to FIG.

In FIG. 1, reference numeral 3 denotes a distributed multimedia server device according to the present invention, which is a communication server module 311 for communicating with a terminal and terminating a terminal interface.
To 31M, storage server modules 321 to 32N for storing multimedia information and reading it out upon request, and a server module network 33 for performing communication between the communication server module and the storage server module. 1
Reference numerals 1 to 1L denote terminals, and 2 denotes a terminal-side network. Reference numeral 4 denotes a multimedia information input device that issues a write request to store multimedia information for distribution in the distributed multimedia server device 3.

FIG. 2 is a block diagram showing the configuration of the communication server module, and FIG. 3 is a block diagram showing the configuration of the storage server module. FIG.
Each of the communication server modules 311 to 31M includes a communication control unit 51, a central control unit 52, a storage unit 53, a system bus 54, and a communication control unit 55 between server modules. Each of the storage server modules 321 to 32N includes a storage unit 61, a central control unit 62, a storage unit 63, a system bus 64, and a communication control unit 65 between server modules. The central control unit 52 executes a program for realizing the present invention stored in the storage unit 53. Further, the central control unit 62 executes a program for realizing the present invention stored in the storage unit 63.

The block configuration of the server module in the single multimedia server device shown in FIG. 13 and the server module in the conventional distributed multimedia server device shown in FIG.
Is not provided, and instead, there is an inter-server module communication control unit 55 for controlling communication with another server module. In the case of the storage server module shown in FIG. 3, the communication control unit 911 shown in FIG.
There is no server module communication control unit 65 instead.

The network 33 between server modules comprises:
It is sufficient that information can be transferred at high speed between arbitrary server modules, and various realization methods such as an ATM switch and a high-speed LAN can be considered. For the concrete implementation method,
Since a known technique can be used, a detailed description is omitted here.

[0026] This system can be used when the number of connected terminals or the load on the distributed multimedia server increases.
By adding a communication server module or a storage server module, or both of them, it is possible to flexibly cope with the problem. For example, by displaying the load status of the system, the administrator can be prompted to add a communication server module or a storage server module, and the number of communication server modules and storage server modules is automatically set according to the load status. It can be changed.

The multimedia information of one program is divided into fixed-length segments, and a plurality of storage server modules 3
It is distributed and stored in 21 to 32N. The operation of the system configured as described above will be described.

(1) A connection request is sent from the terminal 1i (i = 1 to L) to an arbitrary communication server module 31j (j = 1 to M) via the terminal side network 2. (2) When the processing capacity of the communication server module 31j has room and new processing can be performed from the terminal 1i, the communication server module 31j returns a connection response to the terminal 1i, thereby communicating with the terminal 1i. A connection is set up with the server module 31j, and this connection is used for subsequent multimedia information delivery and the like. If there is not enough processing capacity, a connection rejection response including a communication server module identifier having sufficient processing capacity is returned to the terminal 1i. The terminal 1i that has received the connection rejection response makes a connection request to another communication server module 31j 'corresponding to the communication server module identifier having a sufficient processing capacity included in the connection rejection response.

(3) The terminal 1i issues a multimedia information read request including a program identifier to the communication server module 31j. (4) The communication server module 31j that has received the multimedia information read request is the storage server module 32k having the head segment of the program specified by the terminal 1i.
(K = 1 to N) to make a segment read request.

(5) Upon receiving the segment read request, the storage server module 32k reads the segment stored in the storage unit 61, and reads the segment stored in the communication server module 31j.
Transfer to At this time, there is no need to synchronize with another storage server module.

(6) Upon receiving the segment, the communication server module 31j issues a segment read request to the storage server module having the next segment. Similarly,
The reading of the segments from the multiple storage server modules is repeated.

(7) On the other hand, the communication server module 31j periodically delivers the segment to the terminal 1i with the segment reproduction time as one cycle. At this time, the communication server module 31j does not need to synchronize with another communication server module.

(8) When a disconnection request is sent from the terminal 1i to the communication server module 31j, the communication server module 31j returns a disconnection response to the terminal 1i. Connection is disconnected.

Next, an example of a method of accessing multimedia information in the distributed multimedia server device 3 will be described in more detail. FIG. 4 shows a read processing sequence of the distributed multimedia server information access method according to the present embodiment. The read processing is performed as follows.

(1) The communication server module 31j receives a read request for a certain program from the terminal 1i. (2) The communication server module 31j issues a read request to the storage server module 32k storing the first segment of the requested program.

(3) In the storage server module 32k,
Without performing communication with another storage server module, the segment stored in the self-storage server module is read and transferred to the communication server module 31j. The communication server module 31j reads the segment transferred from the storage server module 32k. , To the requesting terminal 1i.

(4) The communication server module 31j receiving the plurality of continuous segments stored in the storage server module 32k issues a read request to the storage server module 32k + 1 storing the subsequent segment.

(5) In the storage server module 32k + 1, similarly to the readout process in the storage server module 32k in (3), the data is stored in the own storage server module without performing communication with another storage server module. Reads the segment that is
j, and the communication server module 31j delivers the segment transferred from the storage server module 32k + 1 to the terminal 1i.

(6) Thereafter, similarly, the storage server module which has received the read request from the communication server module 31j reads out the segment without communicating with other storage server modules, and
Delivery to the terminal 1i via j is repeated.

FIG. 5 is a flowchart showing processing of the communication server module in the present embodiment. The processing of the communication server module will be described according to S1 to S16 shown in FIG.

(S1) A read request from a terminal is received. (S2) An initial delivery time to the terminal is set. For example, if the initial delivery time is set to the time when the read request from the terminal is received, the segment is delivered to the terminal when the segment is received from the storage server module.

(S3) "Segment delivery process to terminal" described later is started. (S4) A segment ID to be read next is calculated, and a storage server module storing the segment is calculated.

(S5) A reception buffer for storing the segments transferred from the storage server module is secured. If the buffer cannot be allocated, wait until the buffer can be allocated. The size of one receiving buffer is equal to the size of one segment, and a plurality of receiving buffers can be used for each terminal.

(S6) A read request is issued to the storage server module calculated in the above step (S4). (S7) The segment corresponding to the read request is received from the storage server module and stored in the reception buffer.

(S8) If it is not the last segment, (S8)
Returning to 4), a segment ID to be read next and a storage server module to issue a read request are calculated.
4) to (S7) are repeated.

The process of delivering a segment to a terminal is performed as follows. (S11) Wait until the current time passes the set “delivery time to terminal”.

(S12) Wait until a segment is stored in the reception buffer. If any of the plurality of receiving buffers stores a segment even in one of the receiving buffers, (S1
Proceed to 3).

(S13) The segment stored in the reception buffer is delivered to the terminal. (S14) The receiving buffer is released. (S15) Currently set “delivery time to terminal”
Plus the playback time of one segment on the terminal,
Set as the next delivery time.

(S16) If it is not the last segment,
The processing of (S11) to (S15) is repeated. Next, a processing sequence of an example of reading a segment of multimedia information using an unused time slot by the time slot processing will be described with reference to FIG. In the access method according to the present embodiment, each storage server module 3
21 to 32N manage the time slots of the self-storage server module only, and perform the reading process as follows according to the processing sequence shown in FIG.

(1) The communication server module 31j receives a read request for a certain program from the terminal 1i. (2) The communication server module 31j issues a read request to the storage server module 32k storing the first segment of the requested program.

(3) In the storage server module 32k,
An unused time slot is selected, and the segment is read out and transferred to the communication server module 31j without notifying the other storage server module of the selected time slot. The communication server module 31j is transferred from the storage server module 32k. Terminal 1i
Deliver to.

(4) The communication server module 31j receiving the plurality of continuous segments stored in the storage server module 32k issues a read request to the storage server module 32k + 1 storing the subsequent segment.

(5) The storage server module 32k + 1 selects an unused time slot and reads out the segment without notifying the other storage server module of the selected time slot.
j, and the communication server module 31j delivers the segment transferred from the storage server module 32k + 1 to the terminal 1i.

(6) Thereafter, similarly, the storage server module receiving the read request from the communication server module selects an unused time slot each time and notifies another storage server module of the selected time slot. Instead, it reads the segment and repeats the delivery to the terminal via the communication server module.

FIG. 7 is a timing chart of the time slot processing in the read processing sequence shown in FIG. 6, and FIG. 8 shows the configuration of the storage server module in the example shown in FIG.

As shown in FIG. 8, two storage server modules (# 1, # 1) are provided in the distributed multimedia server device.
2) There are 321, 322 and each storage server module 3
The storage units 611 and 612 of the storage units 21 and 322 each have 3
Storage devices 6111 to 6113, 6121 to 6123
It is assumed that there is. The multimedia information of one program is divided into fixed-length segments, and each of the storage server modules 321 and 322 has three storage devices 61 respectively.
11 to 6113 and 6121 to 6123.

In the storage server module (# 1) 321, one of TS101, TS102,.
A sequence of three time slots consisting of two time slots at the same interval is periodically generated for each of the storage devices 6111 to 6113. In addition, the storage server module (# 2)
322, TS201, TS202,..., TS2
A sequence of three time slots consisting of twelve twelve equally spaced time slots is periodically generated for each of the storage devices 6121 to 6123. Here, the time slot TS101 of the storage server module (# 1) 321.
.., TS 112 and storage server module (# 2) 322
, And TS212 are independent of each other and are managed only by each storage server module.

Storage server module #j (j = 1, 2)
In, time Cyclej11, Cyclej12, Cyclej13, Cyclej
21,... Are the read cycle (small cycle) of the four time slots constituting the time slot sequence, and the time Cyclej1
Represents a read cycle (large cycle) of 12 time slots constituting a time slot row. One large cycle is composed of three small cycles, and each time slot row is shifted in phase by one small cycle. I have. Here, the short cycle Cycles 111, 112,... Of the storage server module (# 1) 321.
And Cycle2 of the storage server module (# 2) 322
11, 212,... Are independent.

On the other hand, each segment is cyclically stored in the storage device in the storage server module.
Storage device 611 of storage server module (# 1) 321
2, storage device 6113, storage device 6111, and then storage device 6122 of storage server module (# 2) 322,
It is assumed that storage is performed in the order of the storage device 6123 and the storage device 6121.

The processing in the storage server module in this access method is performed as follows, as shown in the flowchart of FIG. When a terminal reads out a certain program and the first segment of the program is stored in the storage device 6112 of the storage server module (# 1) 321, the storage server module (# 1) 321
Search for unused time slots in which read processing and write processing have not been performed for the time slots for the storage device 6112 in the order of TS109, TS110,... (S21 in FIG. 9).

For example, assuming that the TS 109 is an unused time slot, in the short cycle Cycle 111, the segment stored in the storage device 6112 is read out at the timing of the time slot TS 109 (S22) and transferred to the communication server module (S23). ). Next cycle Cycl
In e112, the segment stored in the storage device 6113 at the timing of the same time slot TS109 is read, and in the next short cycle Cycle 113, the segment stored in the storage device 6111 at the timing of the same time slot TS109 is read. Transfer to module. Since the next segment is not stored in the storage server module (# 1) 321, the read processing in the storage server module (# 1) 321 ends (S24).

Similarly, the storage server module (# 2) 322 receiving the read request from the communication server module
Searches for a new unused time slot. For example,
Assuming that the time slot TS210 is an unused time slot, in the short cycle Cycle221, the storage device 612 is used.
2 is read out and transferred to the communication server module. Next, the segments stored in the storage device 6123 in Cycle 222 and the segments stored in the storage device 6121 in Cycle 223 are read and transferred to the communication server.

Thereafter, the storage server module (# 1) 32
1 to search for a new unused time slot,
The same read processing is repeated. FIG. 10 shows a write sequence for storing multimedia information according to the embodiment of the present invention. In the present embodiment, a write process is performed as follows.

(1) The multimedia information input device 4
When storing multimedia information of a program in the distributed multimedia server device 3, a write request is made via the terminal side network 2. Communication server module 31
j receives the multimedia information writing request from the multimedia information input device 4.

(2) The communication server module 31j determines the storage server module 32k to which the head segment of the requested program is to be written, and issues a write request to the storage server module 32k.

(3) The communication server module 31j divides the multimedia information transferred from the multimedia information input device 4 into fixed-length segments and transfers the segments to the storage server module 32k.

(4) The storage server module 32k writes a segment without communicating with another storage server module. (5) Thereafter, similarly, the communication server module 31j
The storage server module for writing the segment is determined cyclically as the storage server modules 32k + 1 and 32k + 2, and the multimedia information transferred from the multimedia information input device 4 is divided into fixed-length segments and determined. The transfer to the stored storage server module is repeated.

Next, a processing sequence for an example of writing a segment of multimedia information using an unused time slot by time slot processing will be described with reference to FIG. In this embodiment, each of the storage server modules 321 to 32N manages a time slot of only the own storage server module, and performs a writing process as follows in accordance with the processing sequence shown in FIG.

(1) The communication server module 31j receives a write request for a certain program from the multimedia information input device 4. (2) The communication server module 31j determines the storage server module 32k in which the head segment of the requested program is to be written, and issues a write request.

(3) In the storage server module 32k,
Select an unused time slot to use for writing the segment. (4) The communication server module 31j divides the multimedia information transferred from the multimedia information input device 4 into fixed-length segments and transfers the segments to the storage server module 32k.

(5) The storage server module 32k writes a segment according to the selected time slot. (6) Thereafter, similarly, the communication server module 31j
The storage server module for writing the segment is determined cyclically as the storage server modules 32k + 1 and 32k + 2, and the multimedia information transferred from the multimedia information input device 4 is divided into fixed-length segments and determined. The transfer to the stored storage server module is repeated.

The timing chart of the time slot process used in the present embodiment is the same as that in FIG. 7, and each segment is cyclically stored in the storage device in the storage server module. For example, the storage server module (# 1) 32
1 storage device 6112, storage device 6113, storage device 6
111, and then the storage devices 6122, 6123, and 612 of the storage server module (# 2) 322
Accumulate in the order of 1.

The processing in the storage server module in this access method is performed as follows, as shown in the flowchart of FIG. When a terminal requests to write a certain program and stores the head segment of the program in the storage device 6112 of the storage server module (# 1) 321, the storage server module (# 1) 321
TS for time slot for storage device 6112
An unused time slot in which read processing and write processing have not been performed is searched in the order of 109, TS110,... (S31 in FIG. 12).

For example, if the TS 109 is an unused time slot, a segment is written to the storage device 6112 at the timing of the time slot TS 109 in the short cycle Cycle 111, and the storage device is written at the same time slot TS 109 in the next cycle Cycle 112. 6
The segment is written to the storage device 6111 at the timing of the same time slot TS109 in the next small cycle Cycle 113 (S32). Since there is no segment to be written next, the writing process in the storage server module (# 1) 321 ends (S3
3).

Since the next segment is stored in the storage device 6122 of the storage server module (# 2) 322, the storage server module (# 2) 322 that has received the write request from the communication server module stores a new unused time slot. To explore. For example, the time slot TS21
If 0 is an unused time slot, the short cycle Cycl
At e221, the segment is written into the storage device 6122, and then at Cycle 222, the storage device 6123, Cycle2
At 23, the segment is written to the storage device 6121.

Thereafter, the storage server module (# 1) 32
1 to search for a new unused time slot,
The same writing process is repeated.

[0077]

As is apparent from the above description, the distributed multimedia server device of the present invention has the following advantages.

(1) The storage server module only has to transfer a segment of multimedia information in accordance with a read request from the communication server module, and does not need to synchronize with another storage server module. In addition, the communication server module may transfer the segment to the terminal at regular intervals without synchronizing with the other communication server modules.

(2) In response to a connection request from a terminal, a segment is delivered using a connection set with the terminal, so that the communication server module always holds connections with all terminals. No need, and
There is no need to repeat disconnection and connection with multiple terminals at short time intervals.

(3) Since there is no control module for controlling the whole in the distributed multimedia server device,
The processing capacity of the entire distributed multimedia server device is not restricted by the processing bottleneck of the control module.

(4) When the communication protocol between the terminal side network or the terminal and the distributed multimedia server device is changed, the effect is limited to the communication server module, and it is necessary to change the entire distributed multimedia server device. Absent.

(5) A communication server module having no margin in processing capacity can distribute a load among a plurality of communication server modules by inducing a connection request to another communication server module when a connection request is made from a terminal. The processing capability of the entire distributed multimedia server device is not restricted by the processing bottleneck of a specific communication server module.

(6) Since the multimedia information of one program is divided into a plurality of fixed-length segments and each segment is distributed and stored in a plurality of storage server modules, the read requests to each storage server module are substantially equal. Yes, due to the processing bottleneck of a specific storage server module,
The processing capacity of the entire distributed multimedia server device is not restricted.

(7) Since it is composed of a plurality of server modules, multimedia information can be distributed simultaneously to a large number of terminals from a single multimedia server device. (8) When the number of connected terminals or the load on the distributed multimedia server device increases, it is possible to flexibly cope with the problem by increasing the number of communication server modules and / or the number of storage server modules.

In particular, the access method according to the present invention has the following advantages. (1) It is not necessary to notify the synchronization information to all storage server modules.

According to the present invention, when a special reproduction request such as a request to read another program or a request to jump to another reproduction position in the same program is issued from the terminal before the reading of a certain program is completed, all of the requests are read. There is no need to notify the storage server module of an access suspension request or new synchronization information based on previously notified synchronization information. Further, the communication server module receiving the trick play request from the terminal stops the delivery of the previous program to the terminal, and then delivers the new program segment transferred from the storage server module. Seems to have a short response time to trick play.

According to the third and fifth aspects, each storage server module manages the time slot of only its own server module. Therefore, when an unused time slot is selected, the selected time slot is notified to all the storage server modules. No need to do. According to the third aspect of the present invention, when a special reproduction request such as a read request for another program or a jump request to another reproduction position in the same program is issued from the terminal before the end of the reading of a certain program, the time point is determined. A time slot release and another unused time slot selection may be performed in the storage server module that is performing the read processing in step 2, and it is not necessary to notify other storage server modules of the time slot release notification and the notification of the newly selected time slot. is there.

(2) Since different storage server modules do not manage the same synchronization information, there is no difference in synchronization information. In claims 3 and 5, since different storage server modules perform different time slot management, the same time slot is not selected.

(3) When a storage server module or a storage device that is a component of the storage server module is added, it is not necessary to change the synchronization information managed by all the storage server modules.

In the third and fifth aspects, when a storage server module or a storage device that is a component of the storage server module is added, only the time slot management information managed by the storage server module needs to be changed. .

(4) Since there is no inconsistency in the synchronization information managed by each storage server module, it is not necessary to periodically check the synchronization information between the storage server modules.

According to the third and fifth aspects, since different storage server modules perform different time slot management, inconsistency of the time slot management information does not occur. (5) Time synchronization in all storage server modules is unnecessary.

In the third and fifth aspects, the phase difference of the time slot between adjacent storage devices in the same storage server module needs to be one small cycle. It is not necessary to keep the phase difference between the time slots of the storage server modules constant, so that time synchronization in different storage server modules is unnecessary.

(6) In claim 3, the maximum response time for a new read request is constant regardless of the number of storage server modules. For example, in FIG. 7, when a new read request is issued, even if the number of storage server modules is doubled, one of 12 time slots in three small cycles is selected, and the maximum response time is 3 minutes. It is a cycle.

(7) In the read processing, the communication server module secures a buffer for receiving the segment and then issues a read request to the storage server module, so that there is no failure in segment transfer due to the buffer shortage of the communication server module. Therefore, the interruption of the reproduction of the multimedia information at the terminal does not occur.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a communication server module.

FIG. 3 is a block diagram illustrating a configuration of a storage server module.

FIG. 4 is a diagram showing a read processing sequence according to the embodiment of the present invention.

FIG. 5 is a flowchart illustrating processing of a communication server module according to the embodiment of the present invention.

FIG. 6 is a diagram showing a read processing sequence according to another embodiment of the present invention.

FIG. 7 is a timing chart of a time slot process in the embodiment shown in FIG. 6;

FIG. 8 is a block diagram illustrating a configuration of a storage server module.

FIG. 9 is a flowchart of a reading process of the storage server module according to the embodiment of the present invention.

FIG. 10 is a diagram showing a write processing sequence according to the embodiment of the present invention.

FIG. 11 is a diagram showing a write processing sequence according to another embodiment of the present invention.

FIG. 12 is a flowchart of a writing process of the storage server module according to the embodiment of the present invention.

FIG. 13 is a block diagram showing a configuration of a conventional single multimedia server device.

FIG. 14 is a block diagram showing a configuration of a system using a conventional distributed multimedia server device.

[Explanation of symbols]

 11 to 1L terminal 2 terminal side network 3 distributed multimedia server device 311 to 31M communication server module 321 to 32N storage server module 33 network between server modules 4 multimedia information input device 51 communication control unit 52 central control unit 53 storage unit 54 system Bus 55 Communication control unit between server modules 61 Storage unit 62 Central control unit 63 Storage unit 64 System bus 65 Communication control unit between server modules

Continuation of the front page (72) Inventor Kazutoshi Nishimura 3-19-2 Nishi Shinjuku, Shinjuku-ku, Tokyo Japan Telegraph and Telephone Corporation

Claims (9)

[Claims] 1. A multimedia server device for delivering multimedia information requested by a terminal to a requesting terminal, wherein the multimedia information divided into segments is stored in units of segments, and a segment read request is issued. On the other hand, a connection is set between a plurality of storage server modules for reading and transferring the requested segment and a terminal, and a request for reading multimedia information from the terminal is received using the connection, and the storage server module A plurality of communication server modules for sending a segment read request to a terminal that has requested multimedia information from a storage server module, and between any of the communication server modules and any of the storage server modules. Server module that can communicate A multimedia server apparatus comprising: 2. A plurality of storage server modules for storing multimedia information having continuity such as video information and audio information, and at least one communication for delivering multimedia information requested by a terminal to each terminal. Server module,
A method of accessing multimedia information in a distributed multimedia server device comprising a network between server modules enabling communication between an arbitrary communication server module and a storage server module, wherein the multimedia information is a distribution target. The divided segments are stored cyclically in a plurality of storage server modules, and when the multimedia information is delivered to the terminal, the communication server module sequentially stores the program in the storage server module at a timing at which the program reproduction at the terminal is not interrupted. A distributed multimedia server information access method, wherein a segment read request is issued to a storage server module, a segment is read without synchronization, and the segment is delivered from a communication module to a terminal. 3. The distributed multimedia server information access method according to claim 2, wherein the segments of the multimedia information are stored in a plurality of storage devices of each of the storage server modules in segment units. The module generates a time slot sequence having a required number of time slots at the same interval, which is independent of other storage server modules, with a phase shifted for each storage device,
In response to a segment read request from the communication server module, an unused time slot is selected from a sequence of time slots, and a segment is read, and a method for accessing distributed multimedia server information is provided. 4. A plurality of storage server modules for storing multimedia information having continuity such as video information and audio information, and at least one communication for delivering multimedia information requested by a terminal to each terminal. Server module,
A method for accessing multimedia information in a distributed multimedia server device comprising a network between server modules enabling communication between an arbitrary communication server module and a storage server module, wherein the communication server module comprises: Upon receiving a multimedia information write request from the media information input device, the multimedia information to be stored for delivery is divided into a plurality of segments, and a segment write request is made cyclically to the plurality of storage server modules. A method of accessing segmented multimedia server information, wherein segment writing is performed without synchronization between storage server modules. 5. The distributed multimedia server information access method according to claim 4, wherein each storage server module has a plurality of storage devices, and each storage server module has the same interval independent of other storage server modules. A time slot sequence having a required number of time slots is generated with a phase shift for each storage device, and an unused time slot is selected from the time slot sequence in response to a segment write request from the communication server module. A method for accessing information of a distributed multimedia server, comprising writing. 6. A plurality of storage server modules for storing multimedia information having continuity such as video information and audio information, and at least one communication for delivering multimedia information requested by a terminal to each terminal. Server module,
A recording medium recording a program used in a distributed multimedia server device configured with a network between server modules that enables communication between an arbitrary communication server module and a storage server module, wherein the communication server module comprises: When delivering multimedia information to a terminal, a segment read request is sequentially sent to a storage server module that cyclically stores segments obtained by dividing the multimedia information to be delivered, at a timing at which program playback at the terminal is not interrupted. For realizing a distributed multimedia server information access method, characterized by recording a program for causing a computer to read a segment without synchronizing between storage server modules and deliver the segment to a terminal. Recording medium on which . 7. A storage medium storing a program for realizing the distributed multimedia server information access method according to claim 6, wherein each storage server module is independent from other storage server modules in the recorded program. , A time slot sequence having a required number of time slots at the same interval is generated with a phase shift for each of a plurality of storage devices storing the segments of the multimedia information held by the self-storage server module, and a segment from the communication server module is generated. A distributed multimedia server information access method characterized by including a program for causing a computer to execute a process of selecting an unused time slot from a time slot sequence and reading a segment in response to a read request. A recording medium on which a program is recorded. 8. A plurality of storage server modules for storing multimedia information having continuity such as video information and audio information, and at least one communication for delivering multimedia information requested by a terminal to each terminal. Server module,
A recording medium recording a program used in a distributed multimedia server device configured with a network between server modules that enables communication between an arbitrary communication server module and a storage server module, wherein the communication server module comprises: Upon receiving a multimedia information writing request from the multimedia information input device,
The multimedia information to be delivered is divided into a plurality of segments, a segment write request is cyclically made to the plurality of storage server modules, and the segments are written without synchronization between the storage server modules. A recording medium recording a program for realizing a distributed multimedia server information access method, characterized by recording a program for causing a computer to execute processing. 9. A recording medium recording a program for realizing the distributed multimedia server information access method according to claim 8, wherein each storage server module is independent of other storage server modules in the recorded program. , A time slot sequence having a required number of time slots at the same interval is generated with a phase shift for each of a plurality of storage devices storing the segments of the multimedia information held by the self-storage server module, and a segment from the communication server module is generated. A distributed multimedia server information access method characterized by including a program for causing a computer to select an unused time slot from a time slot sequence in response to a write request and perform a segment write process on a computer. A recording medium on which a program is recorded.