JP2006345289A - Repeater and terminal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a comfortable communication environment even against the variation of line conditions. <P>SOLUTION: The repeater comprises a transmission error rate detector 31, a line working rate detector 32, a hierarchy allotter 33 for determining the number of layers (layer number) of information source codes contained in coded information sent by a repeater 22 to output hierarchy layer allotting information, a terminal input transmitter-receiver 34 for inputting the priority (priority information) to terminals and hierarchical information (transmit side terminal hierarchical information) to a transmit side communication terminal, a sound information storage 35, a coded information receiver 36, a reconstruction processor 37 for reconstructing the coded information based on the hierarchy layer allotting information, and a coded information transmitter 38 for outputting the reconstructed coded information. In the event of a variation of the line conditions such as line working rate and radio wave conditions, the relay suitably controls the hierarchy of the coded information transmitted to and received from each communication terminal to provide a comfortable communication environment suited to each communication terminal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a relay device and a terminal device used in a communication system that encodes and transmits a signal.

  In recent years, with the development of communication infrastructure, not only simple audio signals but also large-capacity moving image data have been transmitted and received through telephone lines. In this case, variable bit rate transmission methods have been developed to improve the line efficiency by handling audio signals that can be transmitted at low bit rates to moving image data that must be transmitted at high bit rates in the same framework. Yes.

  In addition, in the coding of voice signals and music signals, scalable coding that can decode voice / music signals even from a part of the coded information and suppress the deterioration of sound quality even in the situation where packet loss occurs. Technology has also been developed (see, for example, Patent Document 1).

  As a representative example of this scalable encoding technique, an encoding signal is obtained by encoding an input signal in a first layer encoding unit, and the (i-1) th layer (i is 2 or more) for higher layers. The residual signal, which is the difference between the input signal of the encoding section of the encoding unit) and the decoded signal of the encoded information of the (i-1) -th layer, and the input signal of the i-th layer as an input signal of the i-th layer There has been known a method of repeatedly obtaining encoded information by encoding in a unit.

JP-A-10-97295

  However, in such a conventional acoustic signal encoding method and decoding method, even if a part of the encoded information is lost during transmission, a certain amount of decoded signal can be obtained from the remaining information. How to control the hierarchy of encoded information to be transmitted to each communication terminal when the line usage rate increases and exceeds an allowable value, or how to connect a new communication terminal The processing about whether to accept is not considered.

  In addition, even when the line usage rate has improved or the radio wave conditions have deteriorated, appropriate hierarchical control is performed for each communication terminal enjoying various communication services from low bit rates to high bit rates. Since this is not performed, there is a problem that it cannot be said that a comfortable communication environment is provided for the user.

  The present invention has been made to solve such a conventional problem. When the line condition fluctuates as typified by an increase in the line usage rate, a deterioration in the radio wave condition (an increase in transmission error rate), or the like. Therefore, it is an object of the present invention to provide a relay device that can provide a comfortable communication environment for all users performing communication.

  The relay apparatus of the present invention adjusts the number of layers of encoded information transmitted to each terminal apparatus in accordance with a receiving unit that receives encoded information composed of a plurality of layers by scalable coding, and re-regulates the number of encoded information transmitted to each terminal device. It has a configuration characterized by comprising a reconstruction processing means to be configured and a transmission means for transmitting the encoded information reconstructed by the reconstruction processing means.

  With this configuration, when line conditions such as line usage rate and radio wave conditions fluctuate, it is possible to appropriately control the hierarchy of encoded information transmitted to and received from each communication terminal. A communication environment can be provided. In addition, even when the line usage rate exceeds the allowable value, another new communication can be performed by appropriately controlling the hierarchy of the encoded information transmitted to and received from the communication terminal performing communication at that time. It is also possible to accept terminal connection requests.

  Further, in the relay apparatus according to the present invention, the reconfiguration processing unit has a higher number of layers of encoded information to be transmitted to a terminal device as the terminal has a higher priority based on the priority set for each terminal device. It has the structure characterized by adjusting so that it may become.

  With this configuration, the number of hierarchies is increased according to the priority, so that more information can be transmitted to a terminal with a higher priority.

  Furthermore, the relay apparatus according to the present invention has a configuration characterized in that the reconfiguration processing means adjusts so as to average the number of layers of encoded information transmitted to each terminal apparatus.

  With this configuration, the average number of hierarchies can be transmitted to each terminal device, and information can be transmitted equally to any terminal.

  Furthermore, in the relay device according to the present invention, the reconfiguration processing means calculates a transmission error detection / correction code for detecting and recovering a transmission error of the encoded information for the encoded information transmitted to each terminal device. However, it has a configuration characterized by being added.

  With this configuration, a transmission error detection / correction code is added, so that a transmission error can be corrected in order to obtain a good decoded signal even when the channel condition fluctuates (deteriorates).

  Furthermore, the relay apparatus according to the present invention includes a receiving unit that receives encoded information composed of a plurality of hierarchies by scalable coding, and the number of hierarchies of encoded information that can be received at present by the terminal apparatus of the transmission source from the terminal apparatus. Receiving terminal apparatus information receiving means, reconfiguration processing means for adjusting and reconfiguring the number of layers of encoded information to be transmitted to each terminal apparatus in accordance with information obtained from the terminal apparatus, and reconfiguration in the reconfiguration processing means And a transmission means for transmitting the encoded information.

  With this configuration, the number of layers of encoded information that can be received from a terminal is obtained, and transmission information is reconfigured, so that encoded information can be transmitted with an information amount that matches the reception status of the terminal.

  Further, the terminal device of the present invention encodes a speech signal by scalable coding based on receiving means for receiving coded information composed of a plurality of layers by scalable coding, and control information included in the received coded information. Encoding means for decoding, decoding means for decoding a speech signal by scalable decoding based on control information included in the received encoded information, transmission means for transmitting scalable encoded information, And a terminal device information transmitting means for transmitting the number of encoded information layers that can be received at the present time.

  With this configuration, it is possible to receive the number of layers of encoded information according to the status of the terminal, and to transmit encoded information that has been encoded according to the status of the destination according to the received control information. it can.

  Furthermore, the communication system of the present invention includes a setting information storage device that stores user setting information in which user priorities are set, and a relay device that reconfigures and transmits encoded information composed of a plurality of layers by scalable encoding And the relay apparatus receives the encoded information and the user setting information, a reconfiguration unit that adjusts and reconfigures the number of layers of the encoded information based on the user setting information, A transmission unit configured to transmit the reconstructed encoded information to the terminal device of the user.

  With this configuration, since the encoded information is reconfigured according to the priority of the user, for example, a user with a higher usage fee can receive more information preferentially, and differentiated services according to settings. Provision can be made.

  Further, in the communication system of the present invention, the reconfiguration unit of the relay device reconfigures the encoded information including additional information when the priority of the user set in the user setting information is low. It has the structure characterized by these.

  With this configuration, additional information is given when the user priority is low. For example, advertising audio information can be added as additional information, and services such as providing services at low cost by attaching advertisements can be added. Diversification can be done.

  Furthermore, the communication system of the present invention has a configuration characterized in that the additional information is information received from the setting information storage device or information stored in the relay device.

  With this configuration, since the additional information is received from the setting information storage device or uses information in the relay device, there is no need to prepare a separate communication path to acquire the additional information. Additional information can be acquired.

  Furthermore, the program of the present invention is a program for receiving, in a computer, a reception procedure for receiving encoded information composed of a plurality of layers by scalable encoding, and the number of encoded information layers to be transmitted to each terminal device in accordance with a change in line status. A reconfiguration processing procedure for adjusting and reconfiguring and a transmission procedure for transmitting the reconfigured encoded information are executed.

  With this configuration, when line conditions such as line usage rate and radio wave conditions fluctuate, it is possible to appropriately control the hierarchy of encoded information transmitted to and received from each communication terminal. A communication environment can be provided. In addition, even when the line usage rate exceeds the allowable value, another new communication can be performed by appropriately controlling the hierarchy of the encoded information transmitted to and received from the communication terminal performing communication at that time. It is also possible to accept terminal connection requests.

  Furthermore, the signal processing method of the present invention is a signal processing method used in a multi-party call system, and includes a reception process for receiving encoded information composed of a plurality of layers by scalable encoding, and a change in line status. A reconstruction processing step for adjusting and reconfiguring the number of layers of encoded information to be transmitted to each terminal device, and a transmission step for transmitting the reconstructed encoded information. ing.

  With this configuration, when line conditions such as line usage rate and radio wave conditions fluctuate, it is possible to appropriately control the hierarchy of encoded information transmitted to and received from each communication terminal. A communication environment can be provided. In addition, even when the line usage rate exceeds the allowable value, another new communication can be performed by appropriately controlling the hierarchy of the encoded information transmitted to and received from the communication terminal performing communication at that time. It is also possible to accept terminal connection requests.

  The present invention provides a reconfiguration processing means for adjusting and reconfiguring the number of layers of encoded information to be transmitted to each terminal device in accordance with changes in the line status, thereby changing the line status such as the line usage rate and the radio wave status. In this case, it is possible to appropriately control the hierarchy of encoded information transmitted / received to / from each communication terminal, and to provide a comfortable communication environment according to each communication terminal apparatus. In addition, even when the line usage rate exceeds the allowable value, another new communication can be performed by appropriately controlling the hierarchy of the encoded information transmitted to and received from the communication terminal performing communication at that time. It is also possible to accept terminal connection requests.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In each of the following embodiments, a case where CELP type speech encoding / decoding is performed by a hierarchical signal encoding / decoding method configured by three layers will be described. The hierarchical signal encoding method is a hierarchical structure in which a plurality of signal encoding methods exist in the upper layer for encoding the difference signal between the input signal and the output signal in the lower layer and outputting the encoded information. It is a method that consists of. In the following description, the lowest layer (first layer) is referred to as a “basic layer”, and a layer existing above the basic layer is referred to as an “extension layer”.

(First embodiment)
In the first embodiment, it is assumed that there is some priority set by the service providing side for each terminal device, and when the line usage rate, transmission error rate, etc. fluctuate, A case will be described in which the relay apparatus controls the hierarchy of encoded information so that a more comfortable communication environment is provided.

  FIG. 1 is a diagram showing a system configuration including a relay device and a terminal device according to the present embodiment, where terminal device 10A to terminal device 10N and scalable coding / decoding respectively with a counterpart terminal device via relay device 22 This shows a state in which communication is performed by the conversion method.

  The terminal devices 10A to 10N transmit the encoded information to the relay device 22 via the transmission path 21, and receive the encoded information transmitted from the relay device 22.

  The relay device 22 receives the encoded information transmitted from the terminal devices 10A to 10N, and transmits the obtained encoded information to the relay device group 24 via the transmission path 23. Further, the relay device 22 receives the encoded information transmitted via the transmission path 23 and transmits it to the terminal devices 10A to 10N via the transmission path 21.

  Here, the relay device group 24 in the figure is a communication network in which a plurality of relay devices are connected via a transmission path, and the management center (managing the relay device 22 and the terminal devices 10A to 10N) ( The setting information storage device) is also included in the relay device group 24.

  Also, it is assumed that transmission mode information is included in the encoded information. Here, the transmission mode information is information indicating a transmission bit rate when an input signal is encoded and transmitted, and one transmission bit rate is a transmission mode among two or more predetermined transmission bit rates. Selected as information. In the present embodiment, it is assumed that the transmission mode information can take values of three predetermined transmission bit rates bitrate1, bitrate2, and bitrate3 (bitrate1 <bitrate2 <bitrate3).

  Moreover, in the following description, when showing the specific terminal device in terminal device 10A-terminal device 10N, it describes with the terminal device 10. FIG.

  FIG. 2 is a diagram illustrating an internal configuration of a transmission / reception part (downstream side) of the relay device 22. The transmission / reception part (upstream side) of the relay device 22 is the same as the function of the conventional relay device except for a part thereof, so that the description thereof is omitted in this embodiment.

  As shown in the figure, the relay device 22 detects a transmission error and calculates a transmission error rate, and a transmission error rate detection unit 31 detects a communication line usage rate and calculates a line usage rate. 32, the layer allocation unit 33 for determining the number of layers (number of layers) of the information source code included in the encoded information transmitted by the relay device 22 and outputting the layer allocation information, and the terminal device 10 via the transmission path 23 A terminal that inputs priority (priority information) and hierarchical information (transmission source terminal hierarchical information) for the transmission source communication terminal, and outputs information related to the number of layers (information amount) transmitted to each of the terminal devices 10A to 10N Information transmission / reception unit (terminal device information receiving means) 34, input and storage of voice information, voice information storage unit 35 for directly holding voice information, code transmitted from relay device group 24 via transmission path 23 The encoded information receiving unit (receiving unit) 36 for inputting information, the reconstruction processing unit (reconstruction processing unit) 37 for reconstructing the encoded information based on the hierarchy allocation information, and the reconstructed encoded information are applicable. The terminal device 10 includes an encoded information transmission unit (transmission unit) 38 that outputs the data via the transmission path 21. Hereinafter, each process will be described in detail.

  The transmission error rate detection unit 31 detects how much transmission error is currently occurring in the transmission path 21 between each of the communication terminal devices 10A to 10N based on information from the terminal device 10 or the management center. Then, the transmission error rate is calculated and output to the layer allocation unit 33. Here, the transmission error rate is expressed as error1, error2, error3, and error4 in ascending order of error rate, and the transmission error rate detection unit 31 outputs any one of error1 to error4 to the hierarchy allocation unit 33. To do.

  Similar to the transmission error rate detection unit 31, the line usage rate detection unit 32 detects the current usage rate of the communication line based on information from the terminal device 10 or the management center and the like. The usage rate is calculated and output to the tier allocation unit 33. Here, the line usage rate is expressed as use1, use2, use3, and use4 in ascending order of usage rate, and the line usage rate detection unit 32 outputs any one of use1 to use4 to the tier allocation unit 33. To do. The line usage rate detection unit 32 can also calculate the line usage rate by feeding back the information determined by the tier allocation unit 33 during the previous processing.

  The terminal information transmission / reception unit 34 inputs the priority (priority information) for the terminal device 10 that is the target to be transmitted by the relay device 22 from the management center via the transmission path 23, and outputs this to the tier allocation unit 33. . Here, the priority information for the terminal device 10 is expressed as priority1, priority2, priority3, priority4,... In descending order of priority.

  As an example, the priority for the terminal device 10A to the terminal device 10N is set according to a fee paid by the user to the service providing side. In this way, the user can be differentiated and a more flexible service can be provided.

  Further, the terminal information transmitting / receiving unit 34 inputs hierarchical information (transmission source terminal hierarchical information) for the transmission source communication terminal transmitted from the relay apparatus on the transmission source communication terminal side, and outputs this to the hierarchy allocation unit 33.

  Further, the terminal information transmitting / receiving unit 34 inputs information on the number of layers (information amount) to be transmitted to each of the terminal devices 10A to 10N from the layer allocation unit 33, and this is input to the management center and the communication via the transmission path 23. Output to the other relay device.

  Hierarchy allocating unit 33 inputs a transmission error rate from transmission error rate detecting unit 31, inputs a channel usage rate from channel usage rate detecting unit 32, and receives priority information and source terminal hierarchy from terminal information transmitting / receiving unit 34. Information sources included in the encoded information transmitted by the relay device 22 to the terminal devices 10A to 10N after inputting information and further considering the information amount of the transmission error correction code based on the information. The number of code layers (number of layers) is determined, and this is output as layer allocation information to the reconfiguration processing unit 37 together with the transmission error rate, line usage rate and source terminal layer information (here, the transmission error rate and Of the line usage rate, only the information used for determining the number of layers is output to the reconfiguration processing unit 37).

  Further, the tier allocation unit 33 outputs the tier allocation information to the terminal information transmission / reception unit 34 after the number of layers (information amount) to be transmitted to each of the terminal devices 10A to 10N is determined. Further, the hierarchy allocation unit 33 reconstructs the audio information stored in the audio information storage unit 35 when the result is that an auxiliary audio signal for advertisement or the like is allocated to each of the terminal devices 10A to 10N. A control signal is sent to 37. A specific processing outline will be described below.

  When the transmission error rate fluctuates (in this case, particularly increases, for example), the relay device 22 increases the number of transmission errors in the encoded information transmitted to the terminal devices 10A to 10N in order to maintain call quality. A correction code is inserted (the process of adding a transmission error correction code is performed by the reconstruction processing unit 37 described later). At this time, in order not to increase the total amount of information transmitted to each terminal apparatus 10A to 10N, the ratio of the audio signal code in the encoded information transmitted to each terminal apparatus 10A to 10N is reduced. The unit 33 considers the priority information obtained from the terminal information transmission / reception unit 34, preferentially allocates the encoding information layer to the terminal device 10 having a higher priority, and the terminal device 10 having a lower priority is assigned first. In addition, the hierarchy of encoding information is reduced.

  In FIG. 3, the example of control of the number of hierarchy with respect to each terminal device 10A-10N by the hierarchy allocation part 33 is shown. Note that, when the transmission error rate decreases, the relay device 22 performs control that is completely opposite to the control example when the transmission error rate increases.

  The numbers in the figure are layers assigned to audio signal codes in the encoded information transmitted from the relay device 22 to the terminal devices 10A to 10N based on the transmission error rate and the priorities of the terminal devices 10A to 10N. Shows the number. A value of 0 means that no audio signal is transmitted to the terminal device 10. The numerical value in parentheses indicates the amount of information used for a transmission error correction code that is newly added to the encoded information transmitted to each of the terminal apparatuses 10A to 10N in order to prevent quality degradation due to an increase in the transmission error rate. This means the number of minutes. In addition, the notation CM in the figure means that the audio information stored in the audio information storage unit 35 (here, mainly the advertising audio signal) is transmitted in addition to the normal audio signal, The audio information to be added is assigned a normal information amount for one layer. Based on the figure, the tier allocation unit 33 determines the number of tiers allocated to each of the terminal devices 10A to 10N, and outputs this to the reconfiguration processing unit 37 as tier allocation information.

  In addition, the relay device 22 is prepared for an emergency or when a new user can be connected to the line when the line usage rate fluctuates (in this case, particularly increased). The amount of encoded information transmitted to the currently connected terminal device 10 is reduced. At this time, the hierarchy assigning unit 33 considers the priority information obtained from the terminal information transmitting / receiving unit 34, and assigns the encoded information layer preferentially to the terminal device 10 having a high priority, and the priority is low. The hierarchy of encoded information is reduced first from the terminal device 10.

  FIG. 4 shows a control example of the number of hierarchies for each of the terminal devices 10A to 10N by the hierarchy assigning unit 33. Note that, when the line usage rate decreases, the relay device 22 performs control that is completely opposite to the control example when the line usage rate increases.

  The numbers in the figure are layers assigned to audio signal codes in the encoded information transmitted from the relay apparatus 22 to the terminal apparatuses 10A to 10N based on the line usage rate and the priority of the terminal apparatuses 10A to 10N. Shows the number. A value of 0 means that no audio signal is transmitted to the terminal device 10. In addition, the notation CM in the figure means that the audio information stored in the audio information storage unit 35 (here, mainly the advertising audio signal) is transmitted in addition to the normal audio signal, The audio information to be added is assigned a normal information amount for one layer. Based on the figure, the tier allocation unit 33 determines the number of tiers allocated to each of the terminal devices 10A to 10N, and outputs this to the reconfiguration processing unit 37 as tier allocation information.

  In the above description, the tier allocation unit 33 determines the number of tiers to be allocated to the terminal devices 10A to 10N from either the transmission error rate or the line usage rate and the priority information of the terminal device 10. However, the determination method is not limited to this, and the number of hierarchies to be allocated to the terminal apparatuses 10A to 10N may be determined based on both the transmission error rate and the line usage rate.

  The voice information storage unit 35 receives voice information such as advertisement voice from the management center and stores the voice information therein. The voice information includes voice information directly held by the relay device 22 in addition to a method of inputting from the management center. The voice information storage unit 35 outputs the stored voice information to the reconstruction processing unit 37 when a control signal is input from the hierarchy allocation unit 33.

  The encoded information receiving unit 36 receives the encoded information transmitted from the relay device group 24 via the transmission path 23 and outputs it to the reconstruction processing unit 37.

  The reconfiguration processing unit 37 receives the encoded information from the encoded information receiving unit 36, receives the layer allocation information, the transmission source terminal layer information, the transmission error rate, and the line usage rate from the layer allocation unit 33, and Voice information is input from the voice information storage unit 35. Next, the reconstruction processing unit 37 reconstructs the encoded information based on the hierarchy allocation information, and outputs the obtained encoded information to the encoded information transmitting unit 38. In addition, the reconstruction processing unit 37 may newly calculate and add a transmission error correction code based on the layer assignment information and the transmission error rate. A specific processing outline will be described below.

  The reconstruction processing unit 37 obtains encoded information to be transmitted from the encoded information receiving unit 36 to a certain terminal device 10 via the transmission path 23. Next, the reconfiguration processing unit 37 reconfigures the encoded information according to the number of layers allocated to the terminal device 10 from the layer allocation information obtained from the layer allocation unit 33.

  Specifically, the reconfiguration processing unit 37 has, for example, three layers of encoded information (transmission mode information is bitrate3) obtained from the encoded information receiving unit 36 and the hierarchical allocation unit. When the layer allocation information for the terminal device 10 obtained from 33 is two layers, one layer from the upper layer is deleted from the three layers of encoded information, and the transmission mode information is corrected from bitrate3 to bitrate2. These and the transmission source terminal layer information are integrated as new encoded information and output to the encoded information transmitting unit 38.

  Also, the reconstruction processing unit 37 has three layers of encoded information (transmission mode information is bitrate3) obtained from the encoded information receiving unit 36 and obtained from the hierarchical allocation unit 33. When the layer allocation information for the terminal device 10 is one layer, two layers are deleted from the upper layer among the three layers of encoded information, the transmission mode information is modified from bitrate3 to bitrate1, and these and the transmission source The terminal hierarchy information is integrated as new encoded information, and is output to the encoded information transmission unit 38.

  Also, the reconfiguration processing unit 37 has the encoded information for the terminal device 10 obtained from the encoded information receiving unit 36 in two layers (transmission mode information is bitrate2), and is obtained from the hierarchical allocation unit 33. When the layer allocation information for the terminal device 10 is one layer, one layer from the upper layer is deleted from the two layers of encoded information, the transmission mode information is corrected from bitrate2 to bitrate1, and these and the transmission source The terminal hierarchy information is integrated as new encoded information, and is output to the encoded information transmission unit 38.

  The reconstruction processing unit 37 also obtains the number of layers (transmission mode information) of the encoded information for the terminal device 10 obtained from the encoded information receiving unit 36 and the terminal device 10 obtained from the layer allocation unit 33. If the number of layers indicated by the layer allocation information is the same, the encoded information is not processed and is integrated with the source terminal layer information as new encoded information. The data is output to the encoded information transmission unit 38.

  Also, the reconfiguration processing unit 37, when the hierarchical allocation information for the terminal device 10 obtained from the hierarchical allocation unit 33 obtained from the encoded information receiving unit 36 is the 0th layer, Nothing is output to 38.

  Note that, when an auxiliary audio signal for advertising or the like is input from the audio information storage unit 35, the reconstruction processing unit 37 sets an audio information addition flag provided in a redundant portion of encoded information to be transmitted.

  Also, the reconfiguration processing unit 37 receives the transmission error rate from the layer allocation unit 33, and if the layer allocation information for the terminal device 10 indicates a transmission error correction code, the reconfiguration processing unit 37 newly sets the transmission error correction code. Calculated and added to be integrated into new encoded information. At this time, the amount of information used for the transmission error correction code that is newly calculated and added is assumed to be the layer in parentheses in the diagram given in the description of the processing of the layer allocation unit 33.

  Also, the transmission mode information and the source terminal layer information in the encoded information reconstructed by the reconstruction processing unit 37 will be collectively referred to as control information.

  The encoded information transmission unit 38 receives the reconfigured encoded information from the reconfiguration processing unit 37 and outputs it to the corresponding terminal device 10 via the transmission path 21.

  FIG. 5 is a diagram illustrating an internal configuration of the terminal devices 10A to 10N. Since all the terminal devices 10A to 10N have the same configuration, they will be described as the terminal device 10 here.

  The terminal device 10 receives the encoded information via the transmission path 21 and encodes it into an information source code and control information. The terminal device 10 receives the control information, analyzes it, and uses it for decoding. Information to be transmitted (transmission mode information) and information used for encoding (transmission source terminal layer information) 42, information source code and transmission mode information are input, and transmission mode information is A decoding unit (decoding means) 43 for decoding the information source code, an input signal and source terminal layer information are input, and an encoding unit (code) for encoding the input signal based on the source terminal layer information Encoding means) 44 and an encoded information integration unit (transmitting means, terminal device information transmitting means) 45 that inputs and integrates information source codes and transmission mode information and outputs them as encoded information. Hereinafter, each processing block will be described in detail.

  The encoded information separation unit 41 receives the encoded information sent from the relay device 22 via the transmission line 21, separates the encoded information into information source code and control information, and decodes the obtained information source code The control information is output to the control information separation unit 42.

  The control information separator 42 receives the control information from the encoded information separator 41 and analyzes the control information. The control information separation unit 42 analyzes the control information, and then uses information (transmission mode information) used for decoding in the terminal device 10 and information (transmission source terminal layer) used for encoding in the terminal device 10. Information), the transmission mode information is output to the decoding unit 43, and the transmission source terminal layer information is output to the encoding unit 44.

  The decoding unit 43 receives the information source code from the encoded information separation unit 41 and receives the transmission mode information from the control information separation unit 42. The decoding unit 43 decodes the information source code based on the obtained transmission mode information, and obtains an output signal. Here, it is assumed that a transmission error correction code is also included in the information source code, and the decoding unit 43 uses this to decode the code of the speech information portion in the information source code.

  The encoding unit 44 inputs an input signal, receives transmission source terminal layer information from the control information separation unit 42, encodes the input signal based on the obtained transmission source terminal layer information, and obtains an information source code . The encoding unit 44 outputs the obtained information source code and control information to the encoded information integration unit 45.

  Here, the encoding unit 44 is premised on encoding in a hierarchy corresponding to a request from the counterpart terminal apparatus, but may control the hierarchy encoded in the own terminal apparatus 10. In this case, the own terminal device 10 can freely control the bit rate.

  The encoded information integration unit 45 receives the information source code and the transmission mode information from the encoding unit 44, integrates them, and outputs the integrated information to the relay device 22 via the transmission path 21.

  Next, the configuration of the encoding unit 44 of FIG. 5 will be described using the block diagram of FIG. Note that the encoding unit 44 divides the input signal into N samples (N is a natural number), and encodes each frame with N samples as one frame.

  The encoding unit 44 inputs the source terminal layer information and performs on / off control of the control switches 59a, 59b, 59c, and 59d, and outputs the transmission mode information to the encoding operation control unit 51 and the input signal. A base layer encoding unit 52 that performs encoding, a base layer decoding unit 53 that performs decoding on the base layer information source code output from the base layer encoding unit 52, and a base layer decoding unit 53 that receives an input signal. An addition unit 54 that adds a signal obtained by inverting the polarity of the base layer decoded signal output from the first enhancement layer encoding unit 55 that performs encoding on the first differential signal obtained from the addition unit 54, The first enhancement layer decoding unit 56 that performs decoding on the first enhancement layer information source code output from the 1 enhancement layer encoding unit 55, and the first differential signal obtained from the control switch 59c, An adder 57 that adds a signal obtained by inverting the polarity of the first enhancement layer decoded signal output from the first enhancement layer decoding unit 56 and a second differential signal output from the addition unit 57 are encoded. A second enhancement layer encoding unit 58 and control switches 59a, 59b, 59c, 59d are provided.

  First, the source terminal layer information is input to the encoding operation control unit 51.

  Next, the encoding operation control unit 51 performs on / off control of the control switches 59a, 59b, 59c, and 59d according to the input source terminal layer information.

  Specifically, the encoding operation control unit 51 turns on all the control switches 59a, 59b, 59c, and 59d when the source terminal layer information is bitrate3. Also, when the source terminal layer information is bitrate2, the encoding operation control unit 51 turns on the control switches 59a and 59b and turns off the control switches 59c and 59d. Also, when the source terminal layer information is bitrate1, the encoding operation control unit 51 turns off all the control switches 59a, 59b, 59c, and 59d.

  Also, the encoding operation control unit 51 outputs the transmission mode information to the encoding information integration unit 45.

  As described above, the encoding operation control unit 51 performs on / off control of the control switch group according to the transmission source terminal layer information, thereby determining the combination of the encoding units used for encoding the input signal.

  Further, the input signal is input to the base layer encoding unit 52 and the control switch 59a.

  The base layer encoding unit 52 encodes an input signal using a CELP type speech encoding method, and obtains an information source code (hereinafter referred to as a “base layer information source code”) obtained by the encoding. It outputs to the encoding information integration part 45 and the control switch 59b. The internal configuration of base layer encoding unit 52 will be described later.

  When the control switch 59b is on, the base layer decoding unit 53 performs decoding on the base layer information source code output from the base layer encoding unit 52 using a CELP type speech decoding method, A decoded signal obtained by decoding (hereinafter referred to as “base layer decoded signal”) is output to adder 54. Note that the base layer decoding unit 53 does not operate when the control switch 59b is off. The internal configuration of base layer decoding unit 53 will be described later.

  When the control switches 59a and 59b are in the on state, the adder 54 adds a signal obtained by inverting the polarity of the base layer decoded signal to the input signal, and adds the first difference signal as the addition result to the first enhancement layer code To the control unit 55 and the control switch 59c. Note that the adder 54 does not operate when the control switches 59a and 59b are in the OFF state.

  When the control switches 59a and 59b are in the on state, the first enhancement layer encoding unit 55 encodes the first differential signal obtained from the adding unit 54 using a CELP type speech encoding method, The information source code obtained by encoding (hereinafter referred to as “first enhancement layer information source code”) is output to the encoded information integration unit 45 and the control switch 59d. Note that the first enhancement layer encoding unit does not operate when the control switches 59a and 59b are in the off state.

  The first enhancement layer decoding unit 56 uses a CELP type speech decoding method for the first enhancement layer information source code output from the first enhancement layer encoding unit 55 when the control switch 59d is in the ON state. The decoded signal obtained by the decoding (hereinafter referred to as “first enhancement layer decoded signal”) is output to the adding unit 57. The first enhancement layer decoding unit 56 does not operate when the control switch 59d is in the off state.

  When the control switches 59c and 59d are in the ON state, the adding unit 57 adds a signal obtained by inverting the polarity of the first enhancement layer decoded signal to the first differential signal obtained from the control switch 59c. The second differential signal is output to second enhancement layer encoding unit 58. Note that the adder 57 does not operate when the control switches 59c and 59d are in the OFF state.

  The second enhancement layer encoding unit 58 encodes the second differential signal output from the addition unit 57 using the CELP type speech encoding method when the control switches 59c and 59d are in the ON state, The information source code obtained by encoding (hereinafter referred to as “second enhancement layer information source code”) is output to the encoded information integration unit 45. The second enhancement layer encoding unit does not operate when the control switches 59c and 59d are in the off state.

  Next, FIG. 7 shows a data structure (bit stream) of pre-transmission encoded information, which will be described.

  When the transmission mode information (source terminal layer information) is bitrate1, the encoded information is composed of a redundant part including control information and a base layer information source code, as shown in FIG. 7 (a).

  When the transmission mode information (source terminal layer information) is bitrate2, the coding information is redundant including control information, base layer information source code, and first enhancement layer information source code as shown in FIG. 7 (b). It consists of parts.

  When the transmission mode information (source terminal layer information) is bitrate3, the encoded information includes control information, base layer information source code, first enhancement layer information source code, and second information as shown in FIG. It consists of a redundant part including an enhancement layer information source code.

  Here, the redundant part in the data structure in FIG. 7 is a redundant data storage part prepared in the bit stream, such as transmission error detection / correction bits, the above-described transmission source terminal information, advertisements, etc. It is used for storing data such as a flag indicating that an auxiliary audio signal is added and a counter for synchronizing packets.

  Next, the internal configuration of base layer encoding section 52 in FIG. 6 will be described using FIG. Here, a case will be described in which base layer coding section 52 performs CELP type speech coding.

  The preprocessing unit 71 performs a waveform shaping process and a pre-emphasis process on the input signal so as to improve the performance of a high-pass filter process for removing a DC component and a subsequent encoding process, and a signal (Xin) after these processes. Is output to the LPC analysis unit 72 and the addition unit 75.

  The LPC analysis unit 72 performs linear prediction analysis using the signal (Xin) output from the preprocessing unit 71 and outputs the analysis result (linear prediction coefficient) to the LPC quantization unit 73. The LPC quantization unit 73 performs a quantization process on the linear prediction coefficient (LPC) output from the LPC analysis unit 72, outputs the quantized LPC to the synthesis filter 74, and multiplexes a code (L) representing the quantized LPC. To the conversion unit 84.

  The synthesis filter 74 generates a synthesized signal by performing filter synthesis on a driving sound source output from an adder 81 described later using a filter coefficient based on the quantized LPC, and outputs the synthesized signal to the adder 75.

  The adding unit 75 calculates the error signal by inverting the polarity of the combined signal output from the combining filter 74 and adding it to the signal (Xin), and outputs the error signal to the auditory weighting unit 82.

  The adaptive excitation codebook 76 stores the driving excitations output by the adding unit 81 in the past in the buffer, and samples one frame from the past driving excitations specified by the signal output from the parameter determination unit 83. It cuts out as an adaptive sound source vector and outputs it to the multiplier 79.

  The quantization gain generation unit 77 outputs the quantization adaptive excitation gain and the quantization fixed excitation gain specified by the signal output from the parameter determination unit 83 to the multiplication unit 79 and the multiplication unit 80, respectively.

  Fixed excitation codebook 78 outputs a fixed excitation vector obtained by multiplying a pulse excitation vector having a shape specified by the signal output from parameter determination section 83 by a diffusion vector to multiplication section 80.

  Multiplication section 79 multiplies the adaptive excitation vector output from adaptive excitation codebook 76 by the quantized adaptive excitation gain output from quantization gain generation section 77 and outputs the result to addition section 81. Multiplication section 80 multiplies the fixed excitation vector output from fixed excitation codebook 78 by the quantized fixed excitation gain output from quantization gain generation section 77 and outputs the result to addition section 81.

  The adder 81 inputs the adaptive excitation vector and the fixed excitation vector after gain multiplication from the multiplier 79 and the multiplier 80, respectively, adds these vectors, and adds the drive sound source as the addition result to the synthesis filter 74 and the adaptive excitation source. The data is output to the code book 76. The driving excitation input to adaptive excitation codebook 76 is stored in the buffer.

  The auditory weighting unit 82 performs auditory weighting on the error signal output from the adding unit 75 and outputs the error signal to the parameter determining unit 83 as coding distortion.

  The parameter determination unit 83 sets the adaptive excitation vector, the fixed excitation vector, and the quantization gain that minimize the coding distortion output from the perceptual weighting unit 82 to the adaptive excitation codebook 76, the fixed excitation codebook 78, and the quantization gain, respectively. The adaptive excitation vector code (A), fixed excitation vector code (F), and excitation gain code (G) that are selected from the generation unit 77 and indicate the selection result are output to the multiplexing unit 84.

  The multiplexing unit 84 receives the code (L) representing the quantized LPC from the LPC quantizing unit 73, the code (A) representing the adaptive excitation vector, the code (F) representing the fixed excitation vector, and the parameter determining unit 83. A code (G) representing the quantization gain is input, and the information is multiplexed and output as a base layer information source code.

  Note that the internal configurations of the first enhancement layer encoding unit 55 and the second enhancement layer encoding unit 58 in FIG. 6 are the same as those of the base layer encoding unit 52, and the type of input signal and the output information source Since only the type of code is different, the description thereof is omitted.

  Next, the internal configuration of base layer decoding section 53 in FIG. 6 will be described using FIG. Here, the case where the base layer decoding unit 53 performs CELP type speech decoding will be described.

  In FIG. 9, the base layer information source code input to the base layer decoding unit 53 is separated into individual codes (L, A, G, F) by the multiplexing / separating unit 91. The separated LPC code (L) is output to the LPC decoding unit 92, the separated adaptive excitation vector code (A) is output to the adaptive excitation codebook 95, and the separated excitation gain code (G) is quantized. The fixed excitation vector code (F) output to the gain generation unit 96 and separated is output to the fixed excitation codebook 97.

  The LPC decoding unit 92 decodes the quantized LPC from the code (L) output from the demultiplexing unit 91 and outputs the decoded LPC to the synthesis filter 93.

  The adaptive excitation codebook 95 extracts a sample for one frame from the past driving excitation designated by the code (A) output from the demultiplexing unit 91 as an adaptive excitation vector and outputs it to the multiplication unit 98.

  The quantization gain generating unit 96 decodes the quantized adaptive excitation gain and the quantized fixed excitation gain specified by the excitation gain code (G) output from the multiplexing / separating unit 91, and sends them to the multiplying unit 98 and the multiplying unit 99. Output.

  The fixed excitation codebook 97 generates a fixed excitation vector specified by the code (F) output from the demultiplexing unit 91 and outputs the fixed excitation vector to the multiplication unit 99.

  Multiplier 98 multiplies the adaptive excitation vector by the quantized adaptive excitation gain and outputs the result to adder 100. Multiplier 99 multiplies the fixed excitation vector by the quantized fixed excitation gain and outputs the result to adder 100.

  The adding unit 100 adds the adaptive excitation vector after gain multiplication and the fixed excitation vector output from the multiplying unit 98 and the multiplying unit 99, generates a driving excitation, and generates a synthesis excitation 93 and an adaptive excitation codebook 95. Output to.

  The synthesis filter 93 performs filter synthesis of the driving sound source output from the addition unit 100 using the filter coefficient decoded by the LPC decoding unit 92, and outputs the synthesized signal to the post-processing unit 94.

  The post-processing unit 94 performs, for the signal output from the synthesis filter 93, processing for improving the subjective quality of speech, such as formant enhancement and pitch enhancement, and processing for improving the subjective quality of stationary noise. And output as a base layer decoded signal.

  The internal configuration of first enhancement layer decoding unit 56 in FIG. 6 is the same as the internal configuration of base layer decoding unit 53, and only the type of input information source code and the type of output signal are different. Therefore, the description is omitted.

  Next, the configuration of the decoding unit 43 in FIG. 5 will be described with reference to FIG.

  The decoding unit 43 receives the information source code and transmission mode information of each layer, controls the control switches 117a and 117b, and outputs the information source code corresponding to each layer. Base layer decoding section 112 that decodes the information source code, first enhancement layer decoding section 113 that decodes the first enhancement layer information source code, and second enhancement layer decoding that decodes the second enhancement layer information source code Unit 114, addition unit 115 that adds the first enhancement layer decoded signal and the second enhancement layer decoded signal according to the states of control switches 117a and 117b, and the base layer decoded signal according to the state of control switch 117a And an addition signal output from the addition unit 115, and an addition unit 116 and control switches 117a and 117b.

  The decoding operation control unit 111 inputs the information source code of each layer from the encoded information separation unit 41 and inputs transmission mode information from the control information separation unit 42. The decoding operation control unit 111 controls the on / off states of the control switch 117a and the control switch 117b according to the obtained transmission mode information, and also includes the base layer decoding unit 112 and the first enhancement layer decoding unit 113. The information source code corresponding to each layer is output to second enhancement layer decoding section 114.

  Specifically, when the transmission mode information is bitrate3, the decoding operation control unit 111 turns on the control switches 117a and 117b and sends the base layer information source code to the base layer decoding unit 112 in the first extension. The layer information source code is output to first enhancement layer decoding section 113, and the second enhancement layer information source code is output to second enhancement layer decoding section 114.

  Also, when the transmission mode information is bitrate2, the decoding operation control unit 111 turns the control switch 117a on, turns the control switch 117b off, and sends the base layer information source code to the base layer decoding unit 112. The first enhancement layer information source code is output to first enhancement layer decoding section 113. At this time, the decoding operation control unit 111 outputs nothing to the second enhancement layer decoding unit 114.

  Also, when the transmission mode information is bitrate1, the decoding operation control unit 111 turns off the control switches 117a and 117b and outputs the base layer information source code to the base layer decoding unit 112. At this time, the decoding operation control unit 111 outputs nothing to the first enhancement layer decoding unit 113 and the second enhancement layer decoding unit 114.

  The base layer decoding unit 112 receives the base layer information source code from the decoding operation control unit 111, decodes this using the CELP type speech decoding method, and then performs base layer decoding on the obtained decoded signal The signal is output to the adding unit 116 as a signal.

  When the control switch 117a is in the on state, the first enhancement layer decoding unit 113 receives the first enhancement layer information source code from the decoding operation control unit 111, and decodes this by the CELP type speech decoding method. Then, the obtained decoded signal is output to addition section 115 as a first enhancement layer decoded signal. The first enhancement layer decoding unit 113 does not operate when the control switch 117a is in the off state.

  When the control switch 117b is in the on state, the second enhancement layer decoding unit 114 receives the second enhancement layer information source code from the decoding operation control unit 111, and decodes this using the CELP type speech decoding method. Then, the obtained decoded signal is output to addition section 115 as a second enhancement layer decoded signal. The second enhancement layer decoding unit 114 does not operate when the control switch 117b is in an off state.

  When both the control switch 117a and the control switch 117b are in the on state, the adding unit 115 receives the first enhancement layer decoded signal from the first enhancement layer decoding unit 113, and also receives the first enhancement layer decoding unit 114 from the second enhancement layer decoding unit 114 The second enhancement layer decoded signal is input, these are added, and the added signal is output to addition section 116 as an added signal.

  Further, when the control switch 117a is in the on state and the control switch 117b is in the off state, the adding unit 115 inputs the first enhancement layer decoded signal from the first enhancement layer decoding unit 113 and adds it as it is The signal is output to the adder 116 as a signal. Adder 115 does not operate when both control switch 117a and control switch 117b are off.

  When the control switch 117a is in the ON state, the adding unit 116 inputs the base layer decoded signal from the base layer decoding unit 112, inputs the addition signal from the adding unit 115, and adds these signals. This is output as an output signal. Further, when the control switch 117a is in the OFF state, the adding unit 116 receives the base layer decoded signal from the base layer decoding unit 112 and outputs this as an output signal.

  When an auxiliary audio signal such as an advertisement is added to the relay device 22 in addition to the normal audio signal, the decoding unit 43 uses the value of the audio information addition flag in the transmitted encoded information based on the value of the audio information addition flag. After the normal audio signal and the added audio signal are decoded separately, they are added and output. This decoding method of additional audio information is disclosed in detail in Japanese Patent Application No. 2004-220867.

  As described above, according to the present embodiment, in a communication system including the relay device 22 that transmits a voice / musical sound signal or the like by using a scalable coding technique, a radio wave condition or a line condition such as a line usage rate is present. In the case of fluctuation, the hierarchy of encoded information to be transmitted and received is appropriately controlled based on the priority assigned to each of the terminal devices 10A to 10N. Thereby, the comfortable communication environment according to the state of each terminal device 10A-10N at the present time can be provided. In addition, even when the line usage rate exceeds the allowable value, another layer is newly created by appropriately controlling the hierarchy of the encoded information to be transmitted to and received from the terminal device 10 performing communication at that time. It is also possible to accept a line connection request from the terminal device 10. In addition, a priority is provided for each of the terminal devices 10A to 10N, communication is performed at a high transmission bit rate (many layers) for the terminal device 10 having a high priority, and the terminal device 10 having a low priority is performed. Communicates at a low bit rate (low hierarchy), and in some cases, the advertising voice can be transmitted and decoded simultaneously with the normal voice signal to differentiate users, more appropriate, and It becomes possible to provide a flexible service.

  Further, the present invention does not limit the hierarchy, and in the hierarchical signal encoding / decoding method composed of a plurality of hierarchies, the residual signal, which is the difference between the input signal and the output signal in the lower layer, is assigned to the upper layer. This can be applied to the case of encoding in layers.

  The present invention also applies to the case where the configuration shown in FIGS. 2 and 5 of the present embodiment is recorded and written on a machine-readable recording medium such as a memory, a disk, a tape, a CD, a DVD, and the like. Can be applied, and the same effect as this embodiment can be obtained.

(Second Embodiment)
In the first embodiment, the service providing side gives priority to each communication terminal, and when the radio wave condition deteriorates or the line usage rate increases, the service providing side gives priority to the communication terminal device with higher priority. The form of assigning a hierarchy of encoding information to the above has been described. In addition to this, as described above, priority is not provided to each communication terminal, and when the line status fluctuates, control is performed so that all communicating communication terminals share the average number of encoded information layers. A system including a relay device that performs the above is also conceivable.

  Therefore, in the present embodiment, as described above, a communication system in which the communication charges of all communication terminals are smoothed when the line status fluctuates (deteriorates) will be described.

  Since the system configuration including the relay device and the terminal device according to the present embodiment is the same as that shown in FIG.

  The internal configuration of the relay device 22 in FIG. 1 is the same as the components in FIG. 2 described above, except for the terminal information transmission / reception unit 34 and the hierarchy allocation unit 33, and thus description thereof is omitted.

  The terminal information transmission / reception unit 34 in the present embodiment inputs group information for the terminal devices 10 </ b> A to 10 </ b> N to be transmitted by the relay device 22 from the management center via the transmission path 23, and inputs this to the tier allocation unit 33. Output. Here, the group information for the terminal devices 10A to 10N indicates a group determined by the communication service received by the terminal device or the performance of the terminal device itself, and in order of transmitting and receiving a large amount of information (hierarchy), group1, It will be written as group2, group3, group4, .... Further, the terminal information transmitting / receiving unit 34 inputs hierarchical information (transmission source terminal hierarchical information) for the transmission source communication terminal transmitted from the relay apparatus on the transmission source communication terminal side, and outputs this to the hierarchy allocation unit 33. Further, the terminal information transmitting / receiving unit 34 inputs information on the number of layers (information amount) to be transmitted to each of the terminal devices 10A to 10N from the layer allocation unit 33, and this is input to the management center and the communication via the transmission path 23. Output to the other relay device.

  Hierarchy allocating unit 33 receives a transmission error rate from transmission error rate detecting unit 31, receives a line usage rate from line usage rate detecting unit 32, and receives group information and source terminal hierarchical information from terminal information transmitting / receiving unit 34. Of the information source code included in the encoded information transmitted by the relay device 22 to each of the terminal devices 10A to 10N, further considering the transmission error correction code length based on these pieces of information. The number of layers (number of layers) is determined, and is output to the reconfiguration processing unit 37 together with the transmission error rate, the line usage rate, and the transmission source terminal layer information as the hierarchy allocation information (here, the transmission error rate and the line usage rate) Of these, only the information used to determine the number of layers is output to the reconstruction processing unit 37).

  Further, the tier allocation unit 33 outputs the information to the terminal information transmission / reception unit 34 after the number of tiers (information amount) to be transmitted to each of the terminal devices 10A to 10N is determined. In addition, when the hierarchical allocation unit 33 results in the allocation of auxiliary audio signals for advertisement or the like to the terminal devices 10A to 10N, the hierarchical allocation unit 33 reconstructs the audio information stored in the audio information storage unit 35. A control signal is sent to the unit 37 for output. A specific processing outline will be described below.

  When the transmission error rate fluctuates (especially when the transmission error rate increases), the relay device 22 increases the amount of encoded information transmitted to each of the terminal devices 10A to 10N in order to maintain the call quality. A transmission error correction code is inserted (a process for adding a transmission error correction code is performed by a reconstruction processing unit 37 described later). At this time, in order not to increase the total amount of information transmitted to each terminal apparatus 10A to 10N, the ratio of the audio signal code in the encoded information transmitted to each terminal apparatus 10A to 10N is reduced. The unit 33 considers the group information obtained from the terminal information transmission / reception unit 34, and preferentially assigns a layer of encoded information to the terminal device 10 to which a large number of layers (information amount) has already been assigned at that time. The layers are allocated so that the number of layers allocated to each of the terminal devices 10A to 10N is averaged.

  In FIG. 11, the example of control of the number of layers with respect to each terminal device 10A-10N by the hierarchy allocation part 33 is shown. Note that, when the transmission error rate decreases, the relay device 22 performs control completely opposite to the control when the transmission error rate increases.

  The numbers in the figure are layers assigned to speech signal codes in the encoded information transmitted from the relay device 22 to the terminal devices 10A to 10N based on the transmission error rate and the group information of the terminal devices 10A to 10N. Shows the number. The numerical value in parentheses indicates the amount of information used for a transmission error correction code newly added to the encoded information transmitted to each of the terminal apparatuses 10A to 10N in order to prevent quality degradation due to an increase in the transmission error rate. This means the number of minutes. In addition, the notation CM in the table means that the audio information stored in the audio information storage unit 35 (here, mainly the advertising audio signal) is transmitted in addition to the normal audio signal, The audio information to be added is assigned a normal information amount for one layer. Based on the figure, the tier allocation unit 33 determines the number of tiers allocated to each of the terminal devices 10A to 10N, and outputs this to the reconfiguration processing unit 37 as tier allocation information.

  In addition, the relay device 22 prepares for an emergency situation or makes a new user connectable to the line when the line usage rate fluctuates (especially when the line usage rate increases). In addition, the amount of encoded information transmitted to the currently connected terminal apparatus 10 is reduced. At this time, the hierarchy allocation unit 33 considers the group information obtained from the terminal information transmission / reception unit 34 and preferentially codes the terminal device 10 to which a large number of layers (information amount) has already been allocated at that time. The number of hierarchization information is reduced, and the hierarchies are assigned so that the number of hierarchies assigned to the terminal apparatuses 10A to 10N is averaged.

  In FIG. 12, the example of control of the number of layers with respect to each terminal device 10A-10N by the hierarchy allocation part 33 is shown. In addition, when the line usage rate decreases, the relay device 22 performs control completely opposite to the control when the line usage rate increases.

  The numbers in the figure are layers assigned to speech signal codes in the encoded information transmitted from the relay device 22 to the terminal devices 10A to 10N based on the line usage rate and the group information of the terminal devices 10A to 10N. Shows the number. In addition, the notation CM in the table means that the audio information stored in the audio information storage unit 35 (here, mainly the advertising audio signal) is transmitted in addition to the normal audio signal, The audio information to be added is assigned a normal information amount for one layer. Based on the figure, the tier allocation unit 33 determines the number of tiers allocated to each of the terminal devices 10A to 10N, and outputs this to the reconfiguration processing unit 37 as tier allocation information.

  In the above description, the tier allocation unit 33 determines the number of tiers to be allocated to each of the terminal devices 10A to 10N from either the transmission error rate or the line usage rate and the priority information of the terminal device. The determination method is not limited to this, and the number of hierarchies to be allocated to the terminal apparatuses 10A to 10N may be determined based on both the transmission error rate and the line usage rate.

  The description of the internal configuration of the terminal device 10A to the terminal device 10N is the same as that described in the first embodiment, and is omitted here.

  As described above, according to the present embodiment, in a communication system including the relay device 22 that transmits a voice / musical sound signal or the like by using a scalable coding technique, a radio wave condition or a line condition such as a line usage rate is present. In the case of fluctuation, based on the group information assigned to the terminal device, the hierarchy of the encoded information transmitted / received to / from each of the terminal devices 10A to 10N is averaged as much as possible. Control appropriately. Thereby, the comfortable communication environment according to each communication terminal 10A-10N can be provided. In addition, even when the line usage rate exceeds the allowable value, another layer is newly created by appropriately controlling the hierarchy of the encoded information to be transmitted to and received from the terminal device 10 performing communication at that time. It is also possible to accept a line connection request from the terminal device 10.

  Further, the present invention does not limit the hierarchy, and in the hierarchical signal encoding / decoding method composed of a plurality of hierarchies, the residual signal, which is the difference between the input signal and the output signal in the lower layer, is assigned to the upper layer. This can be applied to the case of encoding in layers.

  The present invention also applies to the case where the configuration shown in FIG. 5 of the present embodiment is recorded and written on a machine-readable recording medium such as a memory, a disk, a tape, a CD, a DVD, and the like. Therefore, the same actions and effects as those of the present embodiment can be obtained.

  As described above, the relay device according to the present invention can appropriately control the hierarchy of encoded information transmitted to and received from each communication terminal when the line status such as the line usage rate and the radio wave status fluctuates. It has the effect of providing a comfortable communication environment according to each communication terminal device, and is useful as a relay device and a terminal device used in a communication system that encodes and transmits a signal.

The block diagram which shows the structure of the communication system in the 1st Embodiment of this invention. Block diagram showing the internal configuration of the relay device Correspondence table indicating the number of layers allocated according to the transmission error rate and priority by the layer allocation unit Correspondence table showing the number of hierarchies allocated according to the line usage rate and priority by the hierarchy allocation unit Block diagram showing internal configuration of terminal device The block diagram which shows the internal structure of the encoding part in a terminal device Data structure diagram of encoded information transmitted from terminal device and relay device The block diagram which shows the internal structure of the base layer encoding part of an encoding part. The block diagram which shows the internal structure of the base layer decoding part of an encoding part. The block diagram which shows the internal structure of the decoding part in a terminal device Correspondence table showing the transmission error rate by the layer allocation unit and the number of layers allocated according to the group Correspondence table showing the line usage rate by the hierarchy allocation unit and the number of hierarchies allocated according to groups

Explanation of symbols

10A to 10N Terminal device 21 Transmission path 22 Relay device 23 Transmission path 24 Relay device group 31 Transmission error rate detection unit 32 Line usage rate detection unit 33 Hierarchy allocation unit 34 Terminal information transmission / reception unit (terminal device information reception means)
35 Audio information storage unit 36 Encoded information receiving unit (receiving means)
37 Reconfiguration processing unit (reconfiguration processing means)
38 Encoded information transmission unit (transmission means)
41 Encoded information separating unit (receiving means)
42 Control Information Separation Unit 43 Decoding Unit (Decoding Unit)
44 Encoding unit (encoding means)
45 Encoding information integration unit (transmission means, terminal device information transmission means)
51 Coding Operation Control Unit 52 Base Layer Coding Unit 53 Base Layer Decoding Unit 54 Addition Unit 55 First Enhancement Layer Encoding Unit 56 First Enhancement Layer Decoding Unit 57 Addition Unit 58 Second Enhancement Layer Encoding Unit 59a, 59b, 59c, 59d Control switch 71 Preprocessing unit 72 LPC analysis unit 73 LPC quantization unit 74 Synthesis filter 75 Addition unit 76 Adaptive excitation codebook 77 Quantization gain generation unit 78 Fixed excitation codebook 79 Multiplication unit 80 Multiplication unit 81 Addition Unit 82 auditory weighting unit 83 parameter determining unit 84 multiplexing unit 91 demultiplexing unit 92 LPC decoding unit 93 synthesis filter 94 post-processing unit 95 adaptive excitation codebook 96 quantization gain generation unit 97 fixed excitation codebook 98 multiplication unit 99 Multiplication unit 100 Addition unit 111 Decoding operation control unit 112 Base layer decoding unit 113 First extension Layer decoding unit 114 Second enhancement layer decoding unit 115 Adder 116 Adder 117a, 117b Control switch

Claims (11)

Receiving means for receiving encoded information composed of a plurality of layers by scalable encoding;
Reconfiguration processing means for adjusting and reconfiguring the number of layers of encoded information to be transmitted to each terminal device in accordance with changes in the line status;
A relay apparatus comprising: transmission means for transmitting encoded information reconstructed by the reconstruction processing means. The reconfiguration processing means adjusts based on the priority set for each terminal device so that the higher the priority the higher the number of layers of encoded information transmitted to the terminal device. The relay device according to claim 1. The relay apparatus according to claim 1, wherein the reconfiguration processing unit adjusts the number of layers of encoded information transmitted to each terminal apparatus to be averaged. The reconstruction processing means calculates and adds a transmission error detection and correction code for detecting and recovering transmission errors of the encoded information to the encoded information transmitted to each terminal apparatus. The relay device according to any one of claims 1 to 3. Receiving means for receiving encoded information composed of a plurality of layers by scalable encoding;
Terminal device information receiving means for receiving from the terminal device the number of layers of encoded information that can be received at the present time by the terminal device of the transmission source;
Reconfiguration processing means for adjusting and reconfiguring the number of layers of encoded information to be transmitted to each terminal device according to the information obtained from the terminal device;
A relay apparatus comprising: transmission means for transmitting encoded information reconstructed by the reconstruction processing means. Receiving means for receiving encoded information composed of a plurality of layers by scalable encoding;
Encoding means for encoding a speech signal by scalable encoding based on control information included in the received encoded information;
Decoding means for decoding a speech signal by scalable decoding based on control information included in the received encoded information;
Transmission means for transmitting scalable encoded encoding information;
A terminal device comprising: terminal device information transmitting means for transmitting the number of layers of encoded information that can be received at the present time. A setting information storage device for storing user setting information in which the priority of the user is set;
A relay device for reconfiguring and transmitting and receiving encoded information configured in a plurality of layers by scalable encoding,
The relay device includes a receiving unit that receives the encoded information and the user setting information;
Reconfiguration means for adjusting and reconfiguring the number of layers of the encoded information based on the user setting information;
A communication system comprising: transmission means for transmitting the reconstructed encoded information to the terminal device of the user. 8. The reconfiguration unit of the relay apparatus, when the priority of the user set in the user setting information is low, reconfigures by including additional information in the encoded information. Communication system. The communication system according to claim 8, wherein the additional information is information received from the setting information storage device or information stored in the relay device. On the computer,
A reception procedure for receiving encoded information composed of a plurality of layers by scalable encoding;
Reconfiguration processing procedure for adjusting and reconfiguring the number of layers of encoded information to be transmitted to each terminal device in accordance with changes in the line status;
A program for executing a transmission procedure for transmitting the reconstructed encoded information. A signal processing method used in a multi-party call system,
A receiving step of receiving encoded information configured in a plurality of layers by scalable encoding;
A reconfiguration processing step of adjusting and reconfiguring the number of layers of encoded information to be transmitted to each terminal device according to a change in the line status;
A signal processing method comprising: a transmission step of transmitting the reconstructed encoded information.

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