WO2010082236A1 - バッファ制御装置及び無線通信端末 - Google Patents
バッファ制御装置及び無線通信端末 Download PDFInfo
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- WO2010082236A1 WO2010082236A1 PCT/JP2009/002745 JP2009002745W WO2010082236A1 WO 2010082236 A1 WO2010082236 A1 WO 2010082236A1 JP 2009002745 W JP2009002745 W JP 2009002745W WO 2010082236 A1 WO2010082236 A1 WO 2010082236A1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
- H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
- H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
- H04L1/1829—Arrangements specially adapted for the receiver end
- H04L1/1835—Buffer management
- H04L1/1841—Resequencing
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L47/00—Traffic control in data switching networks
- H04L47/10—Flow control; Congestion control
- H04L47/30—Flow control; Congestion control in combination with information about buffer occupancy at either end or at transit nodes
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L49/00—Packet switching elements
- H04L49/90—Buffering arrangements
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L49/00—Packet switching elements
- H04L49/90—Buffering arrangements
- H04L49/9005—Buffering arrangements using dynamic buffer space allocation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
- H04L65/60—Network streaming of media packets
- H04L65/65—Network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP]
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
- H04L65/80—Responding to QoS
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W28/00—Network traffic management; Network resource management
- H04W28/02—Traffic management, e.g. flow control or congestion control
- H04W28/0278—Traffic management, e.g. flow control or congestion control using buffer status reports
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
- H04L1/0056—Systems characterized by the type of code used
- H04L1/0061—Error detection codes
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
- H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
- H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
- H04L1/1812—Hybrid protocols; Hybrid automatic repeat request [HARQ]
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L49/00—Packet switching elements
- H04L49/90—Buffering arrangements
- H04L49/9023—Buffering arrangements for implementing a jitter-buffer
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W8/00—Network data management
- H04W8/02—Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks
- H04W8/04—Registration at HLR or HSS [Home Subscriber Server]
Definitions
- the present invention relates to a buffer control device and a wireless communication terminal that can absorb fluctuations.
- AV data packets constituting audio data and video data (hereinafter referred to as AV data) that are stream-reproduced are transmitted in real time on a high-priority channel in order to prevent image quality degradation and sound quality degradation during stream reproduction.
- RTP Real-time Transport Protocol
- jitter fluctuation
- Such retransmission control includes HARQ control.
- HARQ control include HSDPA (High Speed Downlink Packet Access) defined by 3GPP (Third Generation Partnership Project) and LTE (Long Term Evolution), which is a next generation communication standard.
- HSDPA High Speed Downlink Packet Access
- 3GPP Third Generation Partnership Project
- LTE Long Term Evolution
- FIG. 7 is a diagram illustrating a state in which packets retransmitted from the base station 900 by HARQ control are accumulated in the buffer of the radio communication terminal 800.
- a packet processing method in the wireless communication terminal 800 will be described with reference to FIG.
- Wireless communication terminal 800 sequentially processes packets 1 to 3 that have been normally error-corrected and decoded by demodulation processing and error correction processing, and stores them in an RTP buffer. Then, the wireless communication terminal 800 transmits a NACK for the packet 4 in which a decoding error has occurred due to the demodulation process and the error correction process to the transmission source base station 802 via the wireless network. Further, since the packet 4 is lost, the wireless communication terminal 800 keeps the packet 5 and the packet 6 in the RLC buffer.
- the wireless communication terminal 800 When the wireless communication terminal 800 re-receives the packet 4 from the base station 900, the wireless communication terminal 800 processes the packet 4 together with the packet 5 and the packet 6 stored in the RLC buffer and performs control to rearrange them in the correct order. Thereafter, wireless communication terminal 800 transfers packets 4 to 6 rearranged in the correct order to the RTP buffer.
- the wireless communication terminal 800 performs the same processing for the packets 7 to 9 as the processing for the packets 4 to 6. That is, the wireless communication terminal 800 transmits NACK to the transmission source base station 900 via the wireless network for the packet 7 in which a decoding error has occurred due to demodulation processing and error correction processing. Further, since the packet 7 is lost, the wireless communication terminal 800 keeps the packet 8 and the packet 9 in the RLC buffer. When the wireless communication terminal 800 re-receives the packet 7 from the base station 900, the wireless communication terminal 800 processes the packet 7 together with the packet 8 and the packet 9 stored in the RLC buffer and performs control to rearrange them in the correct order. Thereafter, radio communication terminal 800 transfers packets 7 to 9 rearranged in the correct order to the RTP buffer.
- the packets 5 to 6 and the packets 8 to 9 are retained in the RLC buffer until the packets 4 and 7 can be decoded. Due to such packet retention, the time during which a packet is not processed until the re-received packet 4 and packets 5 to 6 are transferred to the RTP buffer after the packet 3 immediately before the packet 4 is transferred to the RTP buffer. Arise. This time becomes fluctuation (jitter). Note that the fluctuation includes a time until a packet lost due to HARQ retransmission control is retransmitted, a time for staying in the RLC buffer, a time for RLC processing to be transferred to the RTP layer, and the like.
- the amount of RTP packets converted into audio data or video data by the decoder is insufficient.
- the output rate of audio and video is lowered, leading to sound interruption and video degradation.
- sound interruption and video deterioration become significant.
- the buffer control technique disclosed in Patent Document 1 changes the capacity of the RTP buffer according to the electric field strength between the wireless communication terminal and the base station. Therefore, fluctuations in the RTP packet reception interval can be absorbed, and sound interruptions are less likely to occur.
- the above-described fluctuation time width greatly exceeds the unit of fluctuation time width of 1 ms to several ms of the electric field strength between the wireless communication terminal and the base station. Therefore, the fluctuation that can be absorbed by changing the capacity of the RTP buffer is considered to be less dependent on the electric field strength between the wireless communication terminal and the base station.
- An object of the present invention is to provide a buffer control device and a wireless communication terminal that can absorb fluctuations.
- the present invention relates to a buffer control device provided in a communication terminal having a receiving unit that receives data via a network, and in order to rearrange the data received by the receiving unit in a correct order, the data is retained A first data processing unit having a first buffer and performing a process of rearranging the data staying in the first buffer in a correct order; and a second buffering the data processed by the first data processing unit A second data processing unit having a buffer and performing processing for outputting the data buffered in the second buffer in accordance with a predetermined output rate; and an amount of the data remaining in the first buffer. And a control unit that controls at least the capacity of the second buffer. With the above configuration, the capacity of the second buffer that absorbs fluctuations at the time of packet reception can be set to an appropriate value.
- control unit controls the second processing unit to increase the capacity of the second buffer as the retention amount of the data remaining in the first buffer increases.
- the second processing unit is controlled to reduce the capacity of the second buffer as the amount of data retained in the first buffer decreases.
- the buffer control device further includes a decoder that converts the data processed by the second data processing unit into an audio signal and a video signal, and outputs the data output from the second data processing unit to the decoder.
- a decoder that converts the data processed by the second data processing unit into an audio signal and a video signal, and outputs the data output from the second data processing unit to the decoder.
- the present invention also provides a wireless communication terminal including the buffer control device.
- FIG. 1 Block diagram of radio communication terminal 100 according to Embodiment 1 of the present invention
- FIG. The figure which shows the time transition of the RLC packet retention amount of the RLC buffer 133 The figure which shows the time transition of the processing delay (fluctuation) in the RTP buffer 137.
- FIG. 3 is a block diagram showing a configuration of radio communication terminal 300 according to Embodiment 2.
- FIG. 1 is a block diagram of radio communication terminal 100 according to Embodiment 1 of the present invention.
- a radio communication terminal 100 includes an antenna 101, a radio unit 103, a demodulation unit 105, a HARQ buffer 107, an error correction unit 109, an ACK / NACK generation unit 111, a modulation unit 113, MAC unit 115, RLC unit 117, UDP / IP unit 119, RTP unit 121, decoder 123, encoder 125, display 127, speaker 129, microphone 131, RLC buffer 133, and fluctuation absorption
- a buffer adjustment unit 135 and an RTP buffer 137 are provided. With reference to FIG. 1, each component of the radio
- the antenna 101 converts a radio wave received from the base station 200 via a wireless network into a radio signal. Further, the antenna 101 converts the signal transferred from the wireless unit 103 into a radio wave and transmits it to the base station 200.
- the wireless unit 103 converts the carrier wave frequency radio signal converted by the antenna 100 into a frequency band radio signal for the demodulator 102.
- the signal transferred from the modulation unit 113 is converted into a carrier frequency signal and transmitted to the antenna 100.
- the demodulator 102 demodulates the radio signal transferred from the radio unit 101. Then, the demodulator 102 transfers the demodulated signal to the HARQ buffer 107.
- the error correction unit 109 performs error correction decoding processing of a signal (hereinafter referred to as a packet) accumulated in the HARQ buffer 107.
- the error correction unit 109 determines the result of error correction of the packet stored in the HARQ buffer 107 by, for example, CRC (Cyclic Redundancy Check) check.
- the packet constitutes AV data for stream reproduction.
- the ACK / NACK generation unit 111 determines whether the packet can be decoded based on the error correction result of the error correction unit 109. If the packet cannot be decoded, the ACK / NACK generation unit 111 transfers the NACK to the modulation unit 113. If the packet can be decoded, the ACK / NACK generation unit 111 transfers the ACK to the modulation unit 113.
- Modulation section 113 modulates NACK or ACK transferred from ACK / NACK generation section 111.
- the radio unit 103 converts the NACK or ACK frequency modulated by the modulation unit 113 into a carrier frequency.
- the antenna 101 converts NACK or ACK into a radio wave and transmits the radio wave to the base station 200 via a wireless network. Note that, when the base station 200 receives NACK, the base station 20 retransmits the signal that has caused a decoding error in the radio communication terminal 100 to the radio communication terminal 100 after a predetermined time has elapsed.
- the MAC unit 115 extracts an RLC packet from a packet that has been decoded and error-corrected by the error correction unit 109 and becomes decodable. Then, the MAC unit 115 transfers the RLC packet to the RLC unit 117.
- the RLC unit 117 accumulates RLC packets in the RLC buffer 133 in order to control the order of RLC packets. Here, if the order of the RLC packets stored in the RLC buffer 133 is correct, the RLC unit 117 sequentially transfers the RLC packets to the UDP / IP unit 119. If the order of the packets stored in the RLC buffer 133 is not correct, the RLC unit 117 keeps the RLC packets in the RLC buffer 133 until the missing packet is transferred from the MAC unit 115.
- the UDP / IP unit 119 analyzes the IP header / UDP header of the RLC packet transferred from the RLC unit 117. Also, the UDP / IP unit 119 extracts the RTP packet from the RLC packet transferred from the RLC unit 117. Then, the UDP / IP unit 119 transfers the RTP packet to the RTP unit 121.
- the RTP unit 121 accumulates the RTP packet transferred from the RTP 121 in the RTP buffer 137 according to the capacity of the RTP buffer 137 instructed from the fluctuation absorbing buffer adjustment unit 135. In addition, the RTP unit 121 transfers the RTP packets stored in the RTP buffer 137 to the decoder 123 according to a predetermined output rate.
- the decoder 123 converts the RTP packet transferred from the RTP unit 121 into an audio signal or a video signal.
- the decoder 123 transfers the audio signal to the speaker 129.
- the decoder 123 transfers the video signal to the display 127.
- the display 127 displays the video signal transferred from the decoder 123 as a video.
- the speaker 129 outputs the audio signal transferred from the decoder 123 as sound.
- the fluctuation absorbing buffer adjustment unit 135 reads the data amount of the RLC packet staying in the RLC buffer 133. Then, the fluctuation absorbing buffer adjustment unit 135 controls the capacity of the RTP buffer 137 according to the staying amount of the RLC packet staying in the RLC buffer 133. For example, when the amount of RLC packets staying in the RLC buffer 133 is large, the fluctuation absorbing buffer adjustment unit 135 controls the RTP buffer 137 so as to increase the capacity of the RTP buffer 137. In addition, when the amount of RLC packets staying in the RLC buffer 133 is small, the fluctuation absorbing buffer adjustment unit 135 controls the RTP buffer 137 so as to reduce the capacity of the RTP buffer 137.
- FIG. 2 is a schematic diagram showing how packets are stored in each buffer in the wireless communication terminal 100.
- the wireless communication terminal 100 sequentially receives packets 1 to 12 from the base station 200 via the wireless network.
- an error correction decoding error hereinafter referred to as a decoding error
- a decoding error it is assumed that an error correction decoding error has occurred in packet 4 and packet 7 among packets 1 to 12 in demodulation section 105 and error correction section 109.
- Packets 1 to 3 in which no decoding error has occurred in the demodulation unit 105 and the error correction unit 109 are sequentially processed in the RLC unit 117 and the UDP / IP unit 119, and RTP packets 1 to 3 are processed as RTP packets 1 to 3. Accumulated in the buffer 137.
- NACK is transmitted from the antenna 101 to the base station 200 that is the transmission source of the packet 4 for the packet 4 in which the decoding error has occurred in the demodulation unit 105 and the error correction unit 109.
- the packet 5 and the packet 6 are processed by the MAC unit 115 before the packet 4 because the packet 4 cannot be decoded.
- the packet 5 and the packet 6 are not processed by the RLC unit 117 that controls the order of the packets. Therefore, after the RLC packet 5 and the RLC packet 6 are extracted by the MAC unit 115, the RLC packet 5 and the RLC packet 6 remain in the RLC buffer 133.
- the fluctuation absorbing buffer adjustment unit 135 reads from the RLC buffer 133 the data amount of the RLC packet staying in the RLC buffer 133 (the data amount of the RLC packet 5 and the packet 6).
- the base station 200 that has received NACK for the packet 4 retransmits the packet 4 to the wireless communication terminal 100.
- the packet 4 retransmitted from the base station 200 is received by the wireless communication terminal 100 via the antenna 101, transferred to the MAC unit 115 through the decoding process in the demodulation unit 105 and the error correction in the error correction unit 109.
- the MAC unit 115 extracts the RLC packet 4 from the packet 4.
- the RLC packet 4 extracted by the MAC unit 115 is transferred to the RLC unit 117 and stored in the RLC buffer 133.
- the RLC unit 117 rearranges the RLC packets 4 to 6 stored in the RLC buffer 133 in the correct order. Then, the RLC packets 4 to 6 are transferred to the UDP / IP unit 119.
- the UDP / IP unit 119 analyzes the IP header and the UDP header of each of the RLC packets 4 to 6 transferred from the RLC unit 117. Also, the UDP / IP unit 119 extracts the RTP packets 4 to 6 from the RLC packets 4 to 6. Then, the RTP packets 4 to 6 are transferred to the RTP unit 121.
- the RTP packets 4 to 6 processed by the UDP / IP unit 119 are once transferred from the RTP unit 121 to the RTP buffer 137 and stored.
- the capacity of the RTP buffer 137 fluctuates based on the data amount of the RLC packet staying in the RLC buffer 133, and is determined by the absorption buffer adjustment unit 135.
- the RTP unit 121 transfers the RTP packet staying in the RLC buffer 133 to the decoder 123 according to the output rate set in advance to a predetermined value. Then, the decoder 123 converts the RTP packet into an audio signal or a video signal.
- the wireless communication terminal 100 performs the same processing for the packets 7 to 9 as the processing for the packets 4 to 6. That is, the radio communication terminal 100 transmits a NACK to the transmission source base station 200 for the packet 7 in which a decoding error has occurred. Further, since the packet 7 is missing, the wireless communication terminal 100 keeps the packet 8 and the packet 9 in the RLC buffer 133. In addition, the RLC buffer 133 notifies the fluctuation absorption buffer adjustment unit 135 described later of the data amount of RLC packets staying in the RLC buffer 133 (data amount of RLC packets 8 and 9). Then, when receiving the packet 7 retransmitted from the base station 200, the radio communication terminal 100 rearranges the packet 7 together with the packet 8 and the packet 9 stored in the RLC buffer 133 in the correct order by the RLC unit 117. .
- the fluctuation absorbing buffer adjustment unit 135 controls the capacity of the RTP packet stored in the RTP buffer 137. The reason why such control is performed will be described with reference to FIGS.
- FIG. 3 is a diagram showing the temporal transition of the RLC packet retention amount in the RLC buffer 133.
- the vertical axis represents the retention amount of RLC packets in the RLC buffer 133
- the horizontal axis represents elapsed time.
- the retention amount of the RLC packet in the RLC buffer 133 has two peaks A and B.
- the first peak A corresponds to the time when the packets 4 to 6 stay in the RLC buffer 133 in FIG. That is, the data amount of the packets 4 to 6 staying in the RLC buffer 133 is shown.
- the second peak B corresponds to the time when the packets 7 to 9 stay in the RLC buffer 133 in FIG. That is, the data amount of RLC packets 7 to 9 staying in the RLC buffer 133 is shown.
- FIG. 4 is a diagram showing a temporal transition of processing delay (hereinafter referred to as fluctuation) in the RTP buffer 137.
- the vertical axis indicates fluctuations in the RTP buffer 137.
- the horizontal axis shows the same elapsed time as in FIG.
- the temporal transition of fluctuations in the RTP buffer 137 is indicated by a solid line.
- the waveform of the temporal transition of the RLC packet retention amount of the RLC buffer 133 in FIG. 3 is shown in FIG.
- the fluctuation in the RTP buffer 137 is, for example, the packet 5 and the packet 6 staying in the RLC buffer 133 after the packet 3 received immediately before the packet 4 is accumulated in the RTP buffer 137, and the packet that can be decoded. 4 indicates the time until accumulation in the RTP buffer 137.
- the first peak C is that the RLC packet 5 and RLC packet 6 staying in the RLC buffer 133 after the packet 3 is accumulated in the RTP buffer 137 and the packet 4 that can be decoded are stored in the RTP buffer 137. It is time until it is accumulated in.
- the second peak D is that the RLC packet 8 and the RLC packet 9 staying in the RLC buffer 133 after the packets 4 to 6 are accumulated in the RTP buffer 137 and the packet 7 that can be decoded are stored in the RTP buffer 137. Indicates the time until accumulation.
- FIG. 3 and FIG. 4 are compared.
- the time transition of the RLC packet retention amount of the RLC buffer 133 indicated by a one-dot chain line in FIG. 4 is substantially the same waveform as the time transition of fluctuation of the RTP buffer 137 indicated by the solid line in FIG. I understand that. That is, it can be seen that the RLC packet retention amount of the RLC buffer 133 greatly depends on the fluctuation of the RTP buffer 137. Therefore, radio communication terminal 100 according to Embodiment 1 controls the capacity of RTP packets stored in RTP buffer 137 based on the amount of RLC packets retained in RLC buffer 133.
- the buffer control apparatus of radio communication terminal 100 can appropriately control the processing delay (fluctuation) in RTP buffer 137 by the capacity of RTP buffer 137.
- the buffer control device of the radio communication terminal 100 appropriately controls the processing delay (fluctuation) in the RTP buffer 137, so that the RTP packet is sent to the decoder 123.
- a decrease in the output rate can be prevented.
- the wireless communication terminal 100 according to the first embodiment can prevent a decrease in the rate at which the audio data and video data converted by the decoder 123 are output to the speaker 129 and the display 127.
- FIG. 5 is a block diagram showing a configuration of radio communication terminal 300 according to Embodiment 2.
- the wireless communication terminal 300 according to the second embodiment is different from the wireless communication terminal 100 according to the first embodiment in that the RLC unit 117, the RLC buffer 133, the fluctuation absorbing buffer adjustment unit 135, the RTP unit 121, and the RTP buffer 137.
- the RLC unit 317, the RLC buffer 333, the fluctuation absorbing buffer adjustment unit 335, the RTP unit 321, the RTP buffer 337, and the timer 339 are provided.
- the second embodiment is the same as the first embodiment, and in FIG. 5, the same reference numerals are given to the components common to FIG. 1.
- the configuration requirements of the wireless communication terminal 300 will be described with reference to FIG.
- the RLC unit 317 accumulates RLC packets in the RLC buffer 333 in order to control the order of RLC packets. Here, if the order of the RLC packets stored in the RLC buffer 333 is correct, the RLC unit 317 sequentially transfers the RLC packets to the UDP / IP unit 119. If the order of the packets stored in the RLC buffer 333 is not correct, the RLC unit 317 keeps the RLC packets in the RLC buffer 333 until the missing packet is transferred from the MAC unit 115.
- the fluctuation absorbing buffer adjustment unit 335 reads the data amount of the RLC packet staying in the RLC buffer 333. Then, the fluctuation absorbing buffer adjustment unit 335 controls the capacity of the RTP buffer 337 according to the staying amount of the RLC packet staying in the RLC buffer 333. Further, the fluctuation absorbing buffer adjustment unit 335 controls the RLC packet staying in the RLC buffer 333 by the timer 339.
- FIG. 6 is a diagram illustrating a time transition of the remaining amount of RTP packets in the RTP buffer 337.
- the timer 339 measures the time (t2-t1) from time t1 when the remaining amount of RTP packets in the RTP buffer 337 falls below a certain threshold to time t2 when it exceeds the next threshold. Then, the fluctuation absorbing buffer adjustment unit 335 sets a time (t2-t1) for the timer 339 to time out.
- the fluctuation absorbing buffer adjustment unit After time t2, the fluctuation absorbing buffer adjustment unit starts measurement of the time (t2-t1) when the timer 339 times out at time t3 when the remaining amount of RTP packets in the RTP buffer 337 first falls below a certain threshold. 335 controls the timer 339.
- the UDP / IP unit 119 analyzes the IP header / UDP header of the RLC packet transferred from the RLC unit 317. Further, the UDP / IP unit 119 extracts the RTP packet from the RLC packet transferred from the RLC unit 317. Then, the UDP / IP unit 119 transfers the RTP packet extracted from the RLC packet to the RTP unit 321.
- the RTP unit 321 accumulates the RTP packet transferred from the RTP 321 in the RTP buffer 337 according to the capacity of the RTP buffer 337 designated by the fluctuation absorbing buffer adjustment unit 335. In addition, the RTP unit 321 transfers the RTP packets stored in the RTP buffer 337 to the decoder 123 according to a predetermined output rate.
- the fluctuation absorbing buffer adjustment unit 335 performs the RLC
- the RLC packet staying in the buffer 333 is forcibly transferred to the UDP / IP unit 119.
- the RLC packet is processed by the UDP / IP unit 119, converted to an RTP packet by the RTP unit 321, and transferred to the decoder 123. Therefore, the buffer control apparatus of radio communication terminal 300 of Embodiment 2 can maintain a predetermined output rate of RTP unit 321.
- the buffer control apparatus of radio communication terminal 300 according to Embodiment 2 appropriately reduces the processing delay (fluctuation) in RTP buffer 337 depending on the capacity of RTP buffer 337 while maintaining a predetermined output rate of RTP unit 321. Can be controlled.
- the buffer control device of radio communication terminal 300 according to Embodiment 2 appropriately controls the processing delay (fluctuation) in RTP buffer 337, so that the RTP packet Can be prevented from lowering the rate of output to the decoder. Therefore, the wireless communication terminal 300 according to the second embodiment can prevent a decrease in the rate at which the audio data and video data converted by the decoder 123 are output to the speaker 129 and the display 127.
- each functional block used in the description of each of the above embodiments is typically realized as an LSI which is an integrated circuit. These may be individually made into one chip, or may be made into one chip so as to include a part or all of them.
- the name used here is LSI, but it may also be called IC, system LSI, super LSI, or ultra LSI depending on the degree of integration.
- the method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor.
- An FPGA Field Programmable Gate Array
- a reconfigurable processor that can reconfigure the connection and setting of the circuit cells inside the LSI may be used.
- the buffer control device and wireless communication terminal according to the present invention can absorb fluctuations and can be used for portable wireless communication terminals that output AV data.
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Abstract
Description
無線ネットワークにおいて、無線通信端末と基地局間の電界強度が低い場合、無線通信端末が基地局から受信したパケットに、誤りがランダムに発生する。そのため、無線通信端末が、パケットを復調処理及び誤り訂正処理しても、パケットをエラー訂正復号できない(復号エラー)場合がある。このような復号エラーを補償するために、無線通信端末がパケットを復号できないと判定した場合、無線通信端末は、送信元の基地局に復号エラーを示すNACKを自動的に送信する。そして、NACKを受信した基地局は、無線通信端末に復号エラーになったパケットを再送信する。このような再送制御としてHARQ制御がある。HARQ制御の代表的なものとして、例えば、3GPP(Third Generation Partnership Project)で規定されているHSDPA(High Speed Downlink Packet Access)や、次世代の通信規格であるLTE(Long Term Evolution)がある。
無線通信端末800は、復調処理及び誤り訂正処理によって正常にエラー訂正復号されたパケット1~3を、逐次処理してRTPバッファに蓄積する。
そして、無線通信端末800は、無線ネットワークを介して送信元の基地局802に、復調処理及び誤り訂正処理によって復号エラーとなったパケット4について、NACKを送信する。また、無線通信端末800は、パケット4が欠落したので、パケット5及びパケット6をRLCバッファに留めておく。
そして、無線通信端末800は、基地局900からパケット4を再受信すると、RLCバッファに蓄積されていたパケット5及びパケット6とともに、パケット4を処理し、正しい順番に並べ替える制御をする。その後、無線通信端末800は、正しい順番に並べ替えられたパケット4~6を、RTPバッファへ転送する。
つまり、無線通信端末800は、無線ネットワークを介して送信元の基地局900に、復調処理及び誤り訂正処理によって復号エラーとなったパケット7について、NACKを送信する。また、無線通信端末800は、パケット7が欠落したので、パケット8及びパケット9を、RLCバッファに留めておく。
そして、無線通信端末800は、基地局900からパケット7を再受信すると、RLCバッファに蓄積されていたパケット8及びパケット9とともに、パケット7を処理し、正しい順番に並べ替える制御をする。その後、無線通信端末800は、正しい順番に並べ替えられたパケット7~9を、RTPバッファへ転送する。
揺らぎが長いと、デコーダで音声データや映像データに変換されるRTPパケットの量が不足する。その結果、無線通信端末800で、音声や映像の出力レートが低下して、音切れや映像の劣化を招く。特に、パケットが、ストリーム再生用のAVデータを構成する場合には、音切れや映像の劣化が顕著となる。
上記構成により、パケット受信時の揺らぎを吸収する第2バッファの容量を適切な値に設定することができる。
また、上記バッファ制御装置において、前記第1バッファに滞留する前記データの滞留量が小さいほど、前記第2バッファの容量を小さくするよう第2処理部を制御する。
上記構成により、第2バッファからデコーダへの出力レートの低下を防ぐことができる。
図1は、本発明の実施の形態1に係る無線通信端末100のブロック図である。図1に示すように、無線通信端末100は、アンテナ101と、無線部103と、復調部105と、HARQバッファ107と、誤り訂正部109と、ACK/NACK生成部111と、変調部113と、MAC部115と、RLC部117と、UDP/IP部119と、RTP部121と、デコーダ123と、エンコーダ125と、ディスプレイ127と、スピーカ129と、マイク131と、RLCバッファ133と、揺らぎ吸収バッファ調整部135と、RTPバッファ137と、を備える。
図1を参照し、無線通信端末100の各構成要件を説明する。
復調部102は、無線部101から転送された無線信号を復調する。そして、復調部102は復調した信号をHARQバッファ107に転送する。
一方、復調部105及び誤り訂正部109で復号エラーが発生したパケット4について、NACKがアンテナ101から無線ネットワークを介して、パケット4の送信元である基地局200へ送信される。また、パケット5及びパケット6は、パケット4が復号できなかったために、パケット4よりも先にMAC部115での処理がなされる。しかし、パケット4が復号できなかったので、パケット5及びパケット6はパケットの順序制御を行うRLC部117での処理がなされない。したがって、MAC部115でRLCパケット5及びRLCパケット6が取り出された後、RLCパケット5及びRLCパケット6がRLCバッファ133に留まる。
また、無線通信端末100は、パケット7が欠落しているので、パケット8及びパケット9を、RLCバッファ133に留めておく。また、RLCバッファ133は、後述する揺らぎ吸収バッファ調整部135へ、RLCバッファ133に滞留するRLCパケットのデータ量(RLCパケット8及びパケット9のデータ量)を通知する。そして、無線通信端末100は、基地局200から再送信されたパケット7を受信すると、RLCバッファ133に蓄積されていたパケット8及びパケット9とともに、パケット7をRLC部117で、正しい順番に並べ替える。
ここで、RTPバッファ137における揺らぎとは、例えば、パケット4の直前に受信したパケット3がRTPバッファ137に蓄積されてから、RLCバッファ133に滞留するパケット5及びパケット6並びに復号可能となったパケット4が、RTPバッファ137に蓄積されるまでの時間を示す。
特に、パケットがストリーム再生用のAVデータを構成している場合、無線通信端末100のバッファ制御装置は、RTPバッファ137における処理遅延(揺らぎ)を適切に制御することで、RTPパケットをデコーダ123へ出力するレートの低下を防ぐことができる。その結果、第1の実施の形態に係る無線通信端末100は、デコーダ123で変換される音声データや映像データを、スピーカ129やディスプレイ127に出力するレートの低下を防ぐことができる。
図5は、実施の形態2に係る無線通信端末300の構成を示すブロック図である。実施の形態2の無線通信端末300が実施の形態1の無線通信端末100と異なる点は、RLC部117と、RLCバッファ133と、揺らぎ吸収バッファ調整部135と、RTP部121と、RTPバッファ137との代わりに、RLC部317と、RLCバッファ333と、揺らぎ吸収バッファ調整部335と、RTP部321と、RTPバッファ337と、タイマ339と、を備えることである。この点以外は実施の形態1と同様であり、図5において、図1と共通する構成要素には同じ参照符号が付されている。
図5を参照し、無線通信端末300の構成要件を説明する。
101 アンテナ
103 無線部
105 復調部
107 HARQバッファ
109 誤り訂正部
111 ACK/NACK生成部
113 変調部
115 MAC部
117、317 RLC部
119 UDP/IP部
121、321 RTP部
123 デコーダ
125 エンコーダ
127 ディスプレイ
129 スピーカ
131 マイク
133、333 RLCバッファ
135、335 揺らぎ吸収バッファ調整部
137、337 RTPバッファ
200、900 基地局
339 タイマ
Claims (5)
- ネットワークを介してデータを受信する受信部を有する通信端末が備えたバッファ制御装置であって、
前記受信部で受信する前記データを正しい順序に並べ替えるために、当該データを滞留させる第1バッファを有し、当該第1バッファに滞留する前記データを正しい順序に並び替える処理を行う第1データ処理部と、
前記第1データ処理部で処理された前記データをバッファリングする第2バッファを有し、前記第2バッファにバッファリングされた前記データを、所定の出力レートに応じて出力する処理を行う第2データ処理部と、
前記第1バッファに滞留する前記データの量に基づき、少なくとも前記第2バッファの容量を制御する制御部と、
を備えるバッファ制御装置。 - 請求項1に記載のバッファ制御装置において、
前記制御部は、前記第1バッファに滞留する前記データの滞留量が大きいほど、前記第2バッファの容量を大きくするよう前記第2処理部を制御するバッファ制御装置。 - 請求項2に記載のバッファ制御装置において、
前記制御部は、前記第1バッファに滞留する前記データの滞留量が小さいほど、前記第2バッファの容量を小さくするよう第2処理部を制御するバッファ制御装置。 - 請求項1に記載のバッファ制御装置は、更に、
前記第2データ処理部で処理された前記データを、音声信号及び映像信号に変換するデコーダを備え、
前記第2データ処理部から前記デコーダに出力される前記データの単位時間当たりのデータ量が、予め所定の値に設定された出力レートを下回る場合、前記制御部は、前記第1バッファに滞留する前記データを前記第2バッファに出力するよう、前記第1処理部を制御するバッファ制御装置。 - 請求項1乃至請求項4のいずれか一項に記載のバッファ制御装置を備える無線通信端末。
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US8249117B2 (en) * | 2009-12-21 | 2012-08-21 | Qualcomm Incorporated | Dynamic adjustment of reordering release timer |
US8782221B2 (en) * | 2012-07-05 | 2014-07-15 | A10 Networks, Inc. | Method to allocate buffer for TCP proxy session based on dynamic network conditions |
GB2556472B (en) | 2013-08-28 | 2018-09-26 | Metaswitch Networks Ltd | Data processing |
KR102298991B1 (ko) * | 2015-05-22 | 2021-09-07 | 삼성전자 주식회사 | 무선 통신 시스템에서 버퍼 관리 방법 및 장치 |
CN106254924B (zh) * | 2016-10-08 | 2017-09-29 | 广东欧珀移动通信有限公司 | 一种多媒体数据的播放方法、系统及相关设备 |
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Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003264583A (ja) * | 2002-03-08 | 2003-09-19 | Nippon Telegr & Teleph Corp <Ntt> | パケットシェーピング方法及び装置 |
JP2004266724A (ja) * | 2003-03-04 | 2004-09-24 | Matsushita Electric Ind Co Ltd | リアルタイム音声用バッファ制御装置 |
JP2005045741A (ja) * | 2003-07-25 | 2005-02-17 | Sony Corp | 通話装置、通話方法及び通話システム |
JP2008028828A (ja) * | 2006-07-24 | 2008-02-07 | Nec Electronics Corp | 無線通信端末装置 |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5757771A (en) * | 1995-11-14 | 1998-05-26 | Yurie Systems, Inc. | Queue management to serve variable and constant bit rate traffic at multiple quality of service levels in a ATM switch |
US6098124A (en) * | 1998-04-09 | 2000-08-01 | National Instruments Corporation | Arbiter for transferring largest accumulated data block output from data buffers over serial bus |
EP1535413B1 (en) * | 2002-08-09 | 2007-01-17 | Interdigital Technology Corporation | Efficient memory allocation in a wireless transmit/receiver unit |
US20050201471A1 (en) * | 2004-02-13 | 2005-09-15 | Nokia Corporation | Picture decoding method |
JP2006186580A (ja) * | 2004-12-27 | 2006-07-13 | Toshiba Corp | 再生装置およびデコード制御方法 |
TWI401918B (zh) * | 2005-02-03 | 2013-07-11 | Nokia Corp | 傳送指示接收器緩衝架構之緩衝參數信號的通訊方法 |
US8180283B2 (en) * | 2007-02-14 | 2012-05-15 | Alcatel Lucent | Method of providing feedback to a media server in a wireless communication system |
KR101132386B1 (ko) * | 2007-04-13 | 2012-07-16 | 노키아 코포레이션 | 비디오 코더 |
US8095680B2 (en) * | 2007-12-20 | 2012-01-10 | Telefonaktiebolaget Lm Ericsson (Publ) | Real-time network transport protocol interface method and apparatus |
-
2009
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- 2009-06-16 US US13/143,145 patent/US20110267999A1/en not_active Abandoned
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Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003264583A (ja) * | 2002-03-08 | 2003-09-19 | Nippon Telegr & Teleph Corp <Ntt> | パケットシェーピング方法及び装置 |
JP2004266724A (ja) * | 2003-03-04 | 2004-09-24 | Matsushita Electric Ind Co Ltd | リアルタイム音声用バッファ制御装置 |
JP2005045741A (ja) * | 2003-07-25 | 2005-02-17 | Sony Corp | 通話装置、通話方法及び通話システム |
JP2008028828A (ja) * | 2006-07-24 | 2008-02-07 | Nec Electronics Corp | 無線通信端末装置 |
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