Information transmission apparatus, traffic control apparatus, method of managing bandwidth resources using the same and method of admitting a call, using variable-rate encoding

Abstract

A notification parameter file, which time-sequentially shows a characteristic of the transmission rate change corresponding to the durable time of a traffic, is notified to a network from a server comprising a storage medium storing data having a traffic characteristic ensured at a transmission starting time. The network adds the characteristic of the transmission rate change designated by the notified parameter to the traffic characteristic already admitted so as to determine whether or not the traffic is admitted. If the traffic can be admitted, the network allocates a transmission bandwidth resource to the sever based on the characteristic of the transmission rate change designated by the notified parameter.

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates to an information transmission apparatus such as a server used in a system for realizing service such as VOD (Video on Demand) in which stored media is reproduced at real time through a network, and a traffic control apparatus, and a method of managing bandwidth resources using the same and a method of admitting a call. Particularly, the present invention relates to an information transmission apparatus in a system in which information is transmitted by use of the storage media storing data, which is VBR (variable bit rate)-encoded, such as a DVD (digital versatile disk), a traffic control apparatus, a method of managing bandwidth resources using the same, and a method of admitting a call.[0002]In recent years, an interactive video service for practical use is starting in accordance with high-speed and wide bandwidth resources of the network and the development of a digital image technique. VOD is one of typical example ...

AI Technical Summary

Benefits of technology

[0020]It is an object of the present invention to provide an information transmission apparatus, which can use variable rate storage media such as DVDs as video a sever without being re-encoded, and which can prevent a hard load of the sever side and deterioration of an image quality.

[0021]It is an object of the present invention to provide an information transmission apparatus which can efficiently perform a traffic management and a network management without changing a characteristic of a VBR source.

[0022]It is an object of the present invention to provide a, traffic control apparatus which can efficiently perform a traffic management and a network management without changing a characteristic of a VBR source.

[0029]As a result, it is not needed that the traffic characteristic, which VBR-encoded real rime data originally has, be forcibly adjusted to the other traffic characteristic due to the restriction of the network. Thereby, the traffic characteristic can be transmitted in a state that the characteristic of VBR source is unchanged. Moreover, the network side can easily manage and control the traffic, and the efficient management of the network resource can be executed.

[0036]In this case, in the traffic admission determining step, the change of the addition result due to a difference of a traffic start timing from the information transmission apparatus should be preferably considered. Thereby, for example, the traffic start timing from the information transmission apparatus such as the server is shifted to timing at which the result of the addition is reduced. As a result, a refused call rate can be reduced. Moreover, in consideration of a transmission delay and a delay variation, it is determined whether or not the traffic is admitted. Furthermore, when the traffic is cut on the way, the traffic characteristic already admitted is modified based on a notification traffic parameter of the cut traffic. Thereby, the call admission can be more correctly controlled.

Problems solved by technology

However, a statistical multiplexed effect, which is particularly useful as an effective using method of managing the bandwidth resource, is not used in the ATM, the transmission cost of the CBR is high.

However, since the CBR uses the statistical multiplexed effect, the transmission cost is lower than the CBR.

However, since no multiplex effect is used, the communication cost is high.

In case when the VBR video such as DVD is transmitted, if the bandwidth resource is notified to adjust to the peak value of the variable rate transmission, the large number of portions where the allocated bandwidth resource is wasted is generated, the total transmission cost is unnecessarily increased.

Due to this, the above-mentioned flattening causes increase in the buffers of the receiver side, and the manufacturing cost is increased.

In other words, there is actually difficulty in flattening the rate.

Moreover, regarding the portion where bits are allocated at the higher rate in the original source, the amount of bits is decreased, so that the image quality is deteriorated.

If the large MBS (maximum burst size) is allocated to prolong the period of time when the peak can continue, the wasteful allocation of the resource occurs similar to the case of CBR.

This results in the rise of the transmission cost.

This does not meet the demand for the manufacturing cost, and the traffic characteristic must be shaped in accordance with the network request.

As a result, a hard load and the deterioration of the image quality occur.

Thus, in the framework of the existing network, when VBR data such as a motion picture is transmitted at real time in the existing ATM service class as a typical example, the following problems occur.

As a result, the hard load on the server side occurs, and the image quality is largely deteriorated due to the re-encoding operation.

As a result, there occur the hard load and the deterioration of the image quality, even if which are not worse than the case of CBR.

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