JP5270284B2 - Relay device and buffer amount control method - Google Patents

Description

  The present invention relates to a relay device that relays data transmitted from a transmission device to a reception device, and a buffer amount control method that controls a capacity for temporarily holding data received from the transmission device.

  In recent years, broadband communication networks such as the Internet have progressed, and wired broadband systems such as FTTH (Fiber To The Home) and ADSL (Asymmetric Digital Subscriber Line), and wireless broadband systems such as Bluetooth (registered trademark), ZigBee, and WiMAX. Has been built. In such a broadband system, when trying to browse the web, distribute video, etc., the communication device connects to the web server via the relay device and downloads the target data and content.

  The relay device that relays data transmission / reception between the communication device and the Web server as described above temporarily stores data in order to compensate for differences in processing speed and throughput (transfer speed) between the transmission side and the reception side. A buffer is provided. Since the relay device includes a buffer, smooth data transmission / reception can be performed. However, if the throughput from the relay device to the communication device (reception side) is extremely smaller than the throughput from the Web server (transmission side) to the relay device, the buffer cannot absorb the difference and an overflow occurs, which is retained in the buffer. The data that could not be cleared will be discarded.

  In particular, in the case of a wireless broadband system, the wireless communication path between a communication device such as a mobile phone or a PHS (Personal Handy-phone System) terminal and a relay device such as a base station or an access point suffers from various radio wave disturbances, resulting in poor communication quality. It tends to deteriorate and the throughput is often unstable. Accordingly, the wireless broadband system is more likely to overflow the buffer than the wired broadband system, and thus there is a problem that the buffer capacity cannot be fixed.

  For example, it is assumed that a base station as a relay apparatus statically secures a buffer having a predetermined capacity for each session for establishing communication with a communication apparatus. When data from the WAN (Wide Area Network) side to the communication device side is received, the data is held in the statically secured buffer. At this time, if the throughput of wireless communication with the communication device side is extremely lower than the throughput of communication with the WAN side, data exceeding the capacity of the buffer is discarded and overflow occurs.

  Here, in order to avoid overflow, it is conceivable to simply increase the capacity of each buffer. However, if many sessions are registered in the base station, it will cause an extreme increase in storage area and allow it. Therefore, it is necessary to prepare a large-capacity storage medium in vain.

Therefore, the buffer of the relay device is divided into two, one of the divided buffers is statically assigned to each transmission source, and the other buffer is shared and used by all transmission sources, thereby allowing packet discard and congestion control. The technique which suppresses is disclosed (for example, patent document 1).
JP 2003-134157 A

  However, in the technique of Patent Document 1 described above, it is necessary to manage which buffer data to which the data in the shared buffer is statically allocated is equal to the transmission source, and complicated processing is strong. It was done. In addition, since the shared buffer occupies a fixed storage area, a predetermined resource is consumed regardless of the required amount of the buffer.

  Therefore, it is conceivable to provide an expansion buffer corresponding to each of the statically allocated buffers on a one-to-one basis and to uniformly extend the buffer when data is about to overflow. However, in a situation where a static buffer is allocated and managed for each of a large number of sessions such as a base station, expanding all the buffers at the same rate causes an increase in storage area, a sudden decrease in free storage area, and memory installation cost. Increase.

  Even if the expansion buffer is provided randomly, the available sessions are limited depending on the communication connection state of the relay device, which causes unnecessary storage space occupied by the expansion buffer that is not used.

  In view of such problems, the present invention avoids buffer overflow and effectively uses a storage area by dynamically securing a buffer capacity according to the communication connection state of the relay device. It is another object of the present invention to provide a buffer amount control method.

In order to solve the above problems, a typical configuration of the present invention is a relay device that relays data transmitted from a transmission device to a reception device, a reception unit that receives data from the transmission device, and the received data and a plurality of basic buffer, predetermined volume can be held for each session, a transmission unit that transmits the data of the basic buffer to the receiving apparatus, the expansion buffer for expanding the storage capacitor of the basic buffer, the communication connection status of the relay device based on a buffer deriving unit that derives the maximum number of extension buffer, a buffer securing unit to secure the extension buffer number derived limit, the data amount detecting section for detecting the amount of data held in the plurality of basic buffer A buffer allocating unit that allocates an extended buffer secured to a basic buffer whose data amount exceeds the first threshold when the detected data amount exceeds the first threshold; Includes, buffer deriving unit, if the channel is used for communication with the receiving device can not be shared and a control channel (control channel) and the communication channel (traffic channel), number of channels to be released for all channels number + communication connection request × characterized that you derive the maximum number using the (connection request receivable number -1).

The base station statically secures a plurality of basic buffers, and dynamically allocates an extended buffer only to the basic buffer whose stored data amount is large. By dynamically allocating such an expansion buffer, it is possible to avoid overflow of data from the transmission apparatus, and it is possible to suppress the generation of useless expansion buffer and to effectively use the storage area. Further, the buffer deriving unit derives the upper limit number (the maximum number of sessions for which a communication path can be established) based on the communication connection state of the relay device in the stage of securing the capacity of the expansion buffer in advance. With this configuration, it is possible to estimate and secure a necessary and optimum capacity as a storage area to which an expansion buffer can be allocated. Therefore, even in a situation where the storage capacity is limited due to cost, occupied volume, etc., it is possible to effectively secure an expansion buffer and to perform stable communication.
In addition, expansion buffers can be assigned to all sessions, but because the number of sessions that can establish a communication path is limited by the communication connection status of the relay device, secure more expansion buffers than the number (upper limit). Is wasted. In the present invention, when the number of channels to be released for communication connection requests among all channels is set according to the above-described formula under the condition that the channel cannot share the control channel and the communication channel, the connection is determined as a wireless characteristic. The upper limit is determined in relation to the number of requests that can be received.
In order to solve the above problems, another exemplary configuration of the present invention is a relay device that relays data transmitted from a transmission device to a reception device, a reception unit that receives data from the transmission device, and a reception A plurality of basic buffers that can hold a predetermined capacity for each session, a transmission unit that transmits the data of the basic buffer to the receiving device, an expansion buffer that extends the holding capacity of the basic buffer, and a communication connection state of the relay device A buffer deriving unit for deriving the upper limit number of extended buffers, a buffer securing unit for securing the derived upper limit number of extended buffers, and a data amount detecting unit for detecting the amount of data held in a plurality of basic buffers And when the detected data amount exceeds the first threshold, a buffer allocating unit that allocates the extended buffer secured to the basic buffer whose data amount exceeds the first threshold When the channel used for communication with the receiving apparatus can share the control channel and the communication channel, the buffer deriving unit derives the upper limit number using the total number of channels × (number of connection request receivables + 1). It is characterized by doing.
As described above, the session is limited by the communication connection state of the relay device. In the present invention, the upper limit number is obtained by the above-described equation under the condition that the channel can share the control channel and the communication channel.

  A buffer release unit may be further provided that releases the extended buffer when the detected data amount falls below the second threshold after the extended buffer is allocated.

  With this configuration, when the amount of data falls below the second threshold due to an improvement in throughput to the receiving device, that is, when the extended buffer becomes unnecessary, the unnecessary extended buffer can be released, and the resource Effective utilization is possible. It can also be released when the session is disconnected or when the session has not established a communication path for a predetermined time.

  The transmitting unit may transmit data to the receiving device through wireless communication. Even if there is a significant difference between the throughput with the transmission device and the throughput with the reception device, the present invention avoids overflow in the relay device and facilitates data communication between the transmission device and the reception device via the relay device. Is something that can be done. Therefore, stable communication can be performed even when a communication mode such as wireless communication in which communication quality deteriorates and throughput is likely to drop relatively rapidly is used for communication with the receiving apparatus.

In order to solve the above-described problem, another exemplary configuration of the present invention has a capacity in which a relay device that relays data transmitted from a transmission device to a reception device temporarily holds data received from the transmission device. A buffer amount control method for controlling, deriving an upper limit number of extension buffers for expanding the holding capacity of the basic buffer based on a communication connection state of the relay device, securing an extended buffer of the derived upper limit number, The data received from the transmission device is held in the basic buffer for each session, the amount of data held in the basic buffer is detected, and when the detected data amount exceeds the first threshold, the data amount exceeds the first threshold Assign the extended buffer reserved in basic buffer, basic buffer or to send the data of the extended buffer to the receiving apparatus, the channel control feature used for communication with the receiving device If that can not be shared between Le and communication channels, and wherein the deriving the maximum number with the number of channels × releasing for all channels number + communication connection request (connection request receivable number -1).
In order to solve the above-described problem, another exemplary configuration of the present invention has a capacity in which a relay device that relays data transmitted from a transmission device to a reception device temporarily holds data received from the transmission device. A buffer amount control method for controlling, deriving an upper limit number of extension buffers for expanding the holding capacity of the basic buffer based on a communication connection state of the relay device, securing an extended buffer of the derived upper limit number, The data received from the transmission device is held in the basic buffer for each session, the amount of data held in the basic buffer is detected, and when the detected data amount exceeds the first threshold, the data amount exceeds the first threshold The extended buffer secured in the basic buffer is allocated, the basic buffer or extended buffer data is transmitted to the receiving device, and the channel used for communication with the receiving device is controlled. If you can share and Le a communication channel, and wherein the deriving the maximum number using the total number of channels × (connection request receivable number +1).

  The components corresponding to the technical idea of the relay device and the description thereof can be applied to the buffer amount control method.

  As described above, according to the present invention, the buffer capacity is dynamically secured according to the communication connection state of the relay device, so that the buffer overflow can be avoided and the storage area can be used effectively.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiment are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

(Wireless communication system 100)
FIG. 1 is an explanatory diagram showing a schematic connection relationship of the wireless communication system 100. The wireless communication system 100 includes a receiving device 110, a base station 120 as a relay device, a communication network 130 including a WAN, an ISDN (Integrated Services Digital Network) line, a dedicated line, etc., a management server 140, a transmission The apparatus 150 is comprised.

  In this embodiment, a configuration in which the receiving device 110 downloads data from the transmitting device 150 (a configuration in which the transmitting device 150 transmits data to the receiving device 110) will be described in order to facilitate understanding. However, the application range of the present embodiment is not limited to this case, and when uploading data from the reception device 110 to the transmission device 150, the reception device 110 functions as the transmission device 150, and the transmission device 150 serves as the reception device 110. Function. Therefore, both the receiving device 110 and the transmitting device 150 can have the functions of both devices.

  In the present embodiment, the receiving device 110 includes a personal computer, a mobile phone, a PHS terminal, a wireless communication function, a PDA (Personal Digital Assistant), a digital camera, which are connected to a PCMCIA slot or USB (Universal Serial Bus). Various electronic devices such as music players, car navigation systems, portable televisions, game machines, DVD players, and remote controllers can be used. The transmission device 150 is assumed to be various information supply means such as a Web server.

  In the wireless communication system 100, when a user attempts to execute Web browsing, video distribution, etc. through the receiving device 110, the receiving device 110 first makes a wireless communication connection request to the base station 120 within the communicable range. I do. Upon receiving the communication connection request, the base station 120 requests the management server 140 to establish a communication connection with the communication partner (the transmission device 150) via the communication network 130, and the management server 140 communicates between the base station 120 and the transmission device 150. A communication path is secured, and finally communication between the receiving device 110 and the transmitting device 150 is established.

  In such a wireless communication system 100, various wireless communication techniques are employed in order to improve throughput and communication quality between the receiving apparatus 110 and the base station 120. In this embodiment, for example, iBurst (registered trademark) is adopted. iBurst (registered trademark) has a wide communicable distance of about several km, and a maximum communication speed of 2 Mbps is ensured as a communication speed for transmission (transmission from the base station to the receiving apparatus), enabling high-speed digital communication. .

  Therefore, in the wireless communication system 100 using iBurst (registered trademark), the receiving device 110 has data such as e-mail, Web browsing, video distribution, etc. while having mobility and portability like a mobile phone and a PHS terminal. It can be transmitted at high speed.

  In such a wireless communication system 100, when the throughput of communication from the base station 120 to the receiving device 110 is extremely smaller than the throughput of communication from the transmitting device 150 to the base station 120, a buffer provided in the base station 120 However, the difference in throughput cannot be absorbed, and so-called overflow occurs, in which data that cannot be retained is discarded.

  Therefore, in the present embodiment, the base station 120 derives and secures an appropriate capacity for how much buffer should be secured based on the communication connection state between the base station 120 and the receiving device 110, and the secured range. The purpose of this is to avoid the overflow of the buffer and to effectively use the storage area by dynamically expanding the buffer. Hereinafter, the configuration of the base station 120 as a relay apparatus will be described.

(Base station 120)
FIG. 2 is a block diagram illustrating a hardware configuration of the base station 120. As shown in FIG. 2, the base station 120 includes a control unit 210, a memory 212, a wired communication unit 214, and a wireless communication unit 216.

  The control unit 210 manages and controls the entire base station 120 by a semiconductor integrated circuit including a central processing unit (CPU).

  The memory 212 includes a ROM, a RAM, an EEPROM, a nonvolatile RAM, a flash memory, an HDD, and the like, and stores a program processed by the control unit 210. In the present embodiment, the memory 212 includes a basic buffer 250 and an expansion buffer 252.

  The basic buffer 250 is a storage area having a predetermined capacity (for example, 30000 Kbytes) allocated for each session, which is a communication establishment unit between the transmission device 150 and the reception device 110, and temporarily stores data received from the transmission device 150. . Such a basic buffer 250 is prepared so as to allow, for example, 1000 receiving apparatuses 110, and can be shared and used by the receiving apparatuses 110.

  The expansion buffer 252 is a storage area for expanding the storage capacity of the basic buffer 250. Therefore, the basic buffer 250 has a one-to-one correspondence and holds data that could not be accommodated in the basic buffer 250.

  The wired communication unit 214 can be connected to various communication devices including the management server 140 and the transmission device 150 via the communication network 130, and also functions as a reception unit 254 that receives data from the transmission device 150.

  The wireless communication unit 216 establishes wireless communication with the receiving device 110, and executes data communication or voice communication after the communication is established. As such wireless communication, wireless communication based on SDMA (Spatial Division Multiple Access) -TDMA (Time Division Multiple Access) system is executed. The wireless communication unit 216 can apply various communication methods such as CDMA (Code Division Multiple Access) and WiMAX. Further, in the present embodiment, the wireless communication unit 216 functions as a transmission unit 256 that transmits data held in the basic buffer 250 to the reception device 110 in accordance with the communication permission state of the reception device 110, for example, RWIN or communication speed limitation. .

  The control unit 210 also functions as a buffer deriving unit 260, a buffer securing unit 262, a data amount detecting unit 264, a buffer allocating unit 266, and a buffer releasing unit 268.

  The buffer deriving unit 260 derives the upper limit number of the expansion buffer 252 based on the communication connection state of the base station 120.

  A buffer allocation unit 266, which will be described later, dynamically allocates the expansion buffer 252 to the basic buffer 250 whose stored data amount has increased. Here, the buffer deriving unit 260 determines the upper limit number (the maximum number of sessions that can establish a communication path) based on the communication connection state of the base station 120 in the stage of securing the capacity of the expansion buffer 252 in advance. To derive.

  With this configuration, it is possible to estimate and secure a necessary and optimum capacity as a storage area to which the expansion buffer 252 can be allocated. Therefore, the expansion buffer 252 can be effectively secured even in a situation where the storage capacity is limited by cost, occupied volume, etc., and stable communication can be performed. Further, since it is not necessary to prepare as many as the number of basic buffers 250, when the storage area of the expansion buffer 252 is fixed, the unit storage area of the expansion buffer 252 can be increased. Here, the communication connection state of the base station 120 indicates the following state, for example.

  FIG. 3 is an explanatory diagram for explaining a communication connection state. FIG. 3 illustrates a communication connection state when a channel used for communication with the receiving apparatus 110 cannot share a control channel (control channel) CCH and a communication channel (traffic channel) TCH. Here, “cannot be shared” means that the control channel CCH or the communication channel TCH is exclusively assigned to the channel, and when one of them is assigned, the other cannot be assigned. Here, out of 12 (total) channels, the control channel CCH as a channel to be released for communication connection request is one channel, and the other 11 channels are communication channels TCH.

  In FIG. 3A, 11 communication channels TCH have established communication with the receiving device 110, and the communication connection request of the receiving device 110 is accepted on one control channel CCH. In the control channel CCH, communication connection requests from a plurality of receiving apparatuses 110 can be received. For example, in this embodiment, communication connection requests from the three receiving apparatuses 110 can be normally received. Here, when there are communication connection requests from four or more receiving apparatuses 110, transmission data of three or more sessions becomes noise of a radio signal of one session as wireless characteristics, and the communication connection request may not be identified. is there. Therefore, as a result, it becomes impossible to execute communication connection with any receiving device 110. Therefore, even if the extended buffer 252 is allocated to a session that is capable of receiving a communication connection request normally and more than the connection request receivable number, the data stored therein is not transmitted to the receiving apparatus 110. It is not necessary to secure more expansion buffers 252 than the number of connection request receivables.

  Then, as shown in FIG. 3 (b), when one communication channel TCH among 11 communication channels TCH is released and becomes an empty channel 280, the receiving device 110 to which the control channel CCH at that time makes a communication connection request. And establishes communication with one of the communication channels TCH. The free channel 280 is assigned a control channel CCH as shown in FIG. 3C and accepts communication connection requests from one or a plurality of receiving apparatuses 110.

  The extended buffer 252 described above can be allocated to all sessions, that is, all the basic buffers 250. As can be understood with reference to FIG. 3, the communication path between the base station 120 and the receiving device 110 depends on the communication connection state. This is limited, and this is the maximum number of sessions (upper limit) that can establish communication. Therefore, it is useless to secure the expansion buffers 252 that are equal to or larger than the upper limit. In the present embodiment, when the number of channels to be released for communication connection requests among all the channels is set by the above-described formula under the condition that the channel cannot share the control channel CCH and the communication channel TCH, the wireless characteristics The upper limit number is obtained in relation to the connection request receivable number determined as follows.

  In detail, when the channel used for communication with the receiving apparatus 110 cannot share the control channel CCH and the communication channel TCH, the buffer deriving unit 260 is the total number of channels + the number of channels released for communication connection request × (connection The upper limit number is derived using the request receivable number-1). In the example of FIG. 3, since the total number of channels is 12, the number of channels released for communication connection requests is 1, and the number of connection request receivables is 3, the upper limit number is 12 + 1 × (3-1) = 14.

  Of these, the connection request receivable number is determined by communication characteristics, but the number of channels to be released for communication connection requests can be arbitrarily set. For example, when the number of channels to be released for communication connection requests is set to 0 The upper limit is 12, and if the number of channels released for communication connection request is set to 12, the upper limit is 36. However, if the number of channels to be released for communication connection requests is large, connection switching becomes complicated and processing load and power consumption increase. Therefore, the number of channels to be released for communication connection requests is usually 1 or 2. Value is taken.

  Further, when the channel used for communication with the receiving apparatus 110 can share the control channel and the communication channel, the buffer deriving unit 260 derives the upper limit number using the total number of channels × (connection request receivable number + 1). To do.

  FIG. 4 is an explanatory diagram for explaining a case where a channel used for communication with a receiving apparatus can share a control channel and a communication channel. Here, “shared” means that the control channel CCH and the communication channel TCH are switched in a time division manner, and the control channel CCH and the communication channel TCH can exist in the same channel. Therefore, while establishing communication with the receiving device 110 using the channel, it is possible to accept the communication connection requests of the receiving devices 110 that can receive connection requests on the control channel CCH in parallel.

  The buffer securing unit 262 secures the upper limit number of extended buffers 252 derived by the buffer deriving unit 260 in the storage area of the base station 120.

  The data amount detection unit 264 detects the data amount held in the plurality of basic buffers 250.

  When the detected data amount exceeds a first threshold, for example, 90% of the entire storage area of the basic buffer 250 alone, the buffer allocation unit 266 sets the buffer allocation unit to the basic buffer 250 whose data amount exceeds the first threshold. The expansion buffer 252 secured by 262 is allocated (added).

  FIG. 5 is an explanatory diagram for explaining the operation of the buffer allocation unit 266. As shown in FIG. 5, the base station 120 statically secures a plurality of basic buffers 250, and data is transmitted to the receiving apparatus 110 through the basic buffers 250. Then, the buffer allocation unit 266 dynamically allocates the expansion buffer 252 only to the basic buffer 250 in which the retained data amount has increased, that is, the data amount has exceeded the first threshold value. By dynamically allocating the expansion buffer 252, it is possible to avoid overflow of data from the transmission device 150, and it is possible to suppress the generation of useless expansion buffer and to effectively use the storage area. It becomes possible.

  After the expansion buffer 252 is allocated, the buffer release unit 268 expands when the detected data amount falls below a second threshold, for example, 50% of the entire storage area of the basic buffer 250 alone as shown in FIG. Free the buffer.

  With this configuration, when the amount of data falls below the second threshold due to an improvement in throughput to the receiving apparatus 110, that is, when the expansion buffer 252 becomes unnecessary, the unnecessary expansion buffer 252 can be released. It is possible to make effective use of resources. It can also be released when the session is disconnected or when the session has not established a communication path for a predetermined time.

  The base station 120 as the relay device described above dynamically secures the buffer capacity according to the communication connection state of the base station 120, thereby avoiding buffer overflow and effectively using the storage area. .

(Buffer amount control method)
Next, a buffer amount control method will be described in which the above-described base station 120 that relays data transmitted from the transmission device 150 to the reception device 110 controls the capacity for temporarily holding the data received from the transmission device 150.

  FIG. 6 is a flowchart showing a processing flow of the buffer amount control method. First, the buffer deriving unit 260 of the base station 120 derives the upper limit number of the extension buffer 252 based on the communication connection state of the base station 120 (S300), and the buffer securing unit 262 uses the derived upper limit number of extension buffers. 252 is secured (S302).

  When communication is started, the basic buffer 250 holds the data received by the receiving unit 254 for each session (S304), and the data amount detection unit 264 detects the data amount held in the basic buffer 250. (S306).

  Here, the detected data amount is compared with the first threshold value (S308), and if the detected data amount exceeds the first threshold value (YES in S308), the buffer allocation unit 266 determines that the data amount is the first threshold value. After confirming that the extension buffer 252 has not already been assigned to the basic buffer 250 exceeding the threshold (S310), the extension buffer 252 secured by the buffer securing unit 262 is allocated (S312). If the detected data amount does not exceed the first threshold value (NO in S308), the data amount is continuously compared with the second threshold value (S314), and if it is below the second threshold value (YES in S314), the buffer is released. The unit 268 confirms that the expansion buffer 252 is assigned to the basic buffer 250 whose data amount has fallen below the first threshold (S316), and releases the expansion buffer 252 (S318). Finally, the transmission unit 256 transmits the data in the basic buffer 250 or the expansion buffer 252 to the reception device 110 according to the communication permission state of the reception device 110 (S320).

  Also with this buffer amount control method, the capacity of the buffer can be dynamically secured according to the communication connection state of the base station 120, so that it is possible to avoid buffer overflow and to effectively use the storage area.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  Each step in the buffer amount control method of the present specification does not necessarily have to be processed in time series in the order described as the flowchart, and may include processing in parallel or by a subroutine.

  INDUSTRIAL APPLICABILITY The present invention can be used for a relay device that relays data transmitted from a transmission device to a reception device, and a buffer amount control method that controls a capacity for temporarily holding data received from the transmission device.

It is explanatory drawing which showed the rough connection relation of the radio | wireless communications system. It is the block diagram which showed the hardware constitutions of the base station. It is explanatory drawing for demonstrating a communication connection state. It is explanatory drawing for demonstrating the case where the channel utilized for communication with a receiver can share a control channel and a communication channel. It is explanatory drawing for demonstrating operation | movement of a buffer allocation part. It is the flowchart which showed the flow of the process of the buffer amount control method.

Explanation of symbols

110 ... receiving device 120 ... base station (relay device)
DESCRIPTION OF SYMBOLS 150 ... Transmission apparatus 250 ... Basic buffer 252 ... Expansion buffer 254 ... Reception part 256 ... Transmission part 260 ... Buffer derivation part 262 ... Buffer securing part 264 ... Data amount detection part 266 ... Buffer allocation part 268 ... Buffer release part

Claims (6)

A relay device that relays data transmitted from a transmission device to a reception device,
A receiver for receiving data from the transmitter;
A plurality of basic buffers capable of holding a predetermined capacity of the received data for each session;
A transmission unit for transmitting the data of the basic buffer to the reception device;
An expansion buffer for expanding the storage capacitor of said basic buffer,
A buffer deriving unit for deriving the upper limit number of the extension buffer based on the communication connection state of the relay device ;
A buffer securing unit for securing the derived upper limit number of extended buffers;
A data amount detector for detecting the amount of data held in the plurality of basic buffers;
A buffer allocating unit that allocates the reserved extended buffer to a basic buffer whose data amount exceeds the first threshold when the detected data amount exceeds the first threshold;
Equipped with a,
When the channel used for communication with the receiving device cannot share a control channel and a communication channel,
Total number of channels + number of channels released for communication connection request x (number of connection request receivables-1)
Relay apparatus characterized that you derive the maximum number used. A relay device that relays data transmitted from a transmission device to a reception device,
A receiver for receiving data from the transmitter;
A plurality of basic buffers capable of holding a predetermined capacity of the received data for each session;
A transmission unit for transmitting the data of the basic buffer to the reception device;
An expansion buffer for expanding the holding capacity of the basic buffer;
A buffer deriving unit for deriving the upper limit number of the extension buffer based on the communication connection state of the relay device;
A buffer securing unit for securing the derived upper limit number of extended buffers;
A data amount detector for detecting the amount of data held in the plurality of basic buffers;
A buffer allocating unit that allocates the reserved extended buffer to a basic buffer whose data amount exceeds the first threshold when the detected data amount exceeds the first threshold;
With
When the channel used for communication with the receiving device can share the control channel and the communication channel,
Total number of channels x (number of connection requests that can be received + 1)
Splicing device in you, wherein the deriving the maximum number used. 3. The relay apparatus according to claim 1, further comprising: a buffer releasing unit that releases the extended buffer when the detected data amount falls below a second threshold after the extended buffer is allocated. 4. And the transmission unit relay device according to any one of claims 1 to 3, wherein the transmitting data to the receiving device via wireless communication. A relay apparatus that relays data transmitted from a transmission apparatus to a reception apparatus is a buffer amount control method for controlling a capacity for temporarily holding data received from the transmission apparatus,
Based on the communication connection status of the relay device, derive the upper limit number of expansion buffers that expand the storage capacity of the basic buffer,
Reserve the derived upper limit number of extended buffers,
The data received from the transmission device is held in the basic buffer for each session,
Detecting the amount of data held in the basic buffer;
When the detected data amount exceeds a first threshold, the reserved extended buffer is allocated to a basic buffer whose data amount exceeds the first threshold;
Transmitting the data in the basic buffer or the extended buffer to the receiving device ;
When a channel used for communication with the receiving device cannot share a control channel and a communication channel,
Total number of channels + number of channels released for communication connection request x (number of connection request receivables-1)
The buffer amount control method is characterized in that the upper limit number is derived using. A relay apparatus that relays data transmitted from a transmission apparatus to a reception apparatus is a buffer amount control method for controlling a capacity for temporarily holding data received from the transmission apparatus,
Based on the communication connection status of the relay device, derive the upper limit number of expansion buffers that expand the storage capacity of the basic buffer,
Reserve the derived upper limit number of extended buffers,
The data received from the transmission device is held in the basic buffer for each session,
Detecting the amount of data held in the basic buffer;
When the detected data amount exceeds a first threshold, the reserved extended buffer is allocated to a basic buffer whose data amount exceeds the first threshold;
Transmitting the data in the basic buffer or the extended buffer to the receiving device;
When a channel used for communication with the receiving device can share a control channel and a communication channel,
Total number of channels x (number of connection requests that can be received + 1)
The buffer amount control method is characterized in that the upper limit number is derived using.

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