Packet data communication system, portable telephone set and network side equipment

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention minimizes image deterioration by restoring the missing packet data from other packet data when a packet is lost during communication in a video telephone or video distribution in a mobile phone using an IP packet network. It relates to a method of limiting the limit.

【0002】

[Conventional technology]

Generally, in transmission in mobile phones and IP packet networks, in addition to received packet code errors, packet discards due to congestion in the IP network and packet omissions due to deterioration of transmission quality in the wireless section may occur.

【0003】

In order to send voice data that requires real-time performance on the IP network, real-time performance is guaranteed by RTP (Real-time Transport Protocol), and the missing packet data is complemented inside the voice codec.

【0004】

Image data of moving images and TV phones are also converted into RTP packets, but when missing packets occur, specific image frames may be omitted, or when data is supplemented, they may become rough.

【0005】

FIG. 5 shows a conventional embodiment. In Fig. 5, 1 is a mobile phone, 2 is a microphone built into the mobile phone, 3 is a speaker, 4 is an encoder / decoder that converts audio data, 5 is a video camera for a video phone, and 6 is for converting image data. Encoder / decoder, 7 is a synthesizer / separation device that synthesizes / separates audio data and image data, 8 is a device that packetizes data, 10 is a wireless communication unit, 11 is a wireless base station, and 12 is a wireless base station control device. , 13 is a gateway connecting the mobile terminal network and the IP network, and 14 is the IP network.

【0006】

Next, the operation will be described. When communicating via a TV phone, the audio received by the microphone 2 is converted into data by the audio encoder / decoder, and at the same time, the video captured by the camera 5 is also converted into data by the image data encoder / decoder, and image data composition is performed. -Sent to the separator 7. The voice data and the image data are combined by the image data compositing / separating device 7, and packetized by the packetizing device 8. RTP is also implemented in the IP packet in the packetizing device 8.

【0007】

The data packetized by the packetizing device 8 is transmitted to the mobile phone network through the wireless communication unit 10. The transmitted data is transmitted as an IP packet to the IP network 14 through the gateway 13. During this period, packet data is lost in the mobile phone network (especially the wireless communication part) and the IP network.

【0008】

Next, the operation inside the mobile phone on the receiving side when packet data is lost will be described. FIG. 6 shows the operation when packet data is lost in the IP network or the mobile phone network during an actual voice call. When the packetizing device 8 determines that the packet data received by the mobile phone 1 is missing, the voice data encoder / decoder 4 complements the missing data to generate voice data and reproduce the voice from the speaker 3. To do.

【0009】

Figure 7 shows the operation when an IP packet is missing during a videophone call. When the received data is missing, the data is complemented in the same way as the audio, but the image is distorted, and in the worst case, one frame of the moving image may be missing.

【0010】

[Problems to be Solved by the Invention]

When data complementation is performed by the conventional voice codec technology, there are many cases where there is no problem in voice quality even if data complementation occurs to some extent for voice. However, when video such as videophone, video distribution, and digital TV reception is received as packet data by a mobile phone, data complementation and missing image frames can be clearly seen by the human eye in a deteriorated form.

【0011】

In addition, when data matching is performed by retransmitting missing packets, it is difficult to realize it with moving images such as TV telephones and digital TVs that require real-time performance.

【0012】

The present invention has been made to solve the above problems. An object of the present invention is to minimize deterioration of video quality due to data errors and packet omissions that occur in the packet network in mobile phones and IP packet networks, data errors in wireless sections of mobile phones, and lack of continuous packet data. It is to provide technology to limit.

【0013】

[Means for solving problems]

The packet data communication system according to the present invention is a packet data communication system that divides data including video and audio into packet data for communication, and when transmitting the data, each group including a plurality of packet data When parity data is generated in the above group, the parity data is transmitted together, and when the above data is received, if packet data is missing in the above group, it is received with other packet data in the above group. It is characterized in that the missing packet data is reproduced from the parity data of the above group.

【0014】

When transmitting the data, the packet data communication system changes the order of the packet data to be transmitted, and when receiving the data, returns the order of the received packet data to the state before the change at the time of transmission. It is characterized by that.

【0015】

The packet data communication system is characterized by being a mobile phone.

【0016】

The packet data communication system is characterized by being a gateway device for a mobile phone system.

【0017】

The mobile phone according to the present invention receives the transmission unit that transmits the parity data generated for each of a plurality of packets together with the plurality of packets, and the plurality of packets and the parity data transmitted from the communication partner side. When any one of the plurality of packets is missing, it is characterized by including a packet other than the missing packet among the plurality of packets and a receiving unit that reproduces the missing packet based on the parity data. And.

【0018】

The network-side device according to the present invention receives a transmission unit that transmits parity data generated for each of a plurality of packets together with the plurality of packets, and a plurality of packets and parity data transmitted from the communication partner side. When any one of the plurality of packets is missing, it includes a packet other than the missing packet among the plurality of packets and a receiving unit that reproduces the missing packet based on the parity data. It is a feature.

【0019】

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1. First, the present invention will be outlined. The packet communication system in the present invention creates a group for each fixed unit when delivering a moving image to an IP packet network, calculates XOR for each group to generate parity data, and uses this parity data as a data group. It is transmitted at the same time as it is transmitted, and if arbitrary packet data on the receiving side does not reach the receiving side due to packet discard due to congestion or data error occurs, or if it cannot be used, it is missing from other data and parity data in this group. By reproducing the data, the omission of the image data is eliminated.

【0020】

Furthermore, since there is a high possibility that packet data will be continuously lost in the wireless section, even if the transmission order of the packet data of the image data is changed and continuous loss occurs, if the transfer data is viewed in group units, It adjusts so that one packet is missing, and finally reproduces the missing data from the parity data.

【0021】

Hereinafter, the first embodiment will be described with reference to the drawings. In Fig. 1, 1 is a mobile phone, 2 is a microphone built into the mobile phone, 3 is a speaker, 4 is an encoder / decoder that converts audio data, 5 is a video camera for a video phone, and 6 is for converting image data. Encoder / decoder, 7 is a synthesizer / separator that synthesizes / separates audio data and image data, 8 is a device that packetizes data, 9 is an XOR engine that calculates the XOR of data in arbitrary group units, and 10 is wireless. The communication unit, 11 is a wireless base station, 12 is a wireless base station control device, 13 is a gateway connecting a mobile terminal network and an IP network, and 14 is an IP network. The radio base station 11, the radio base station control device 12, or the gateway 13 correspond to, for example, a network-side device.

【0022】

Next, the operation will be described. The operation will be described along with the data flow when communicating by TV telephone. On the data transmission side, the sound received by the microphone 2 is converted into data by the audio encoder / decoder, and at the same time, the video captured by the camera 5 is also converted into data by the image data encoder / decoder.

【0023】

After that, the two data are sent to the image data compositing / separating device 7. The audio data and the image data are combined by the image data compositing / separating device 7. After that, the packetizing device 8 digitizes the data into an arbitrary packet size. For the packetized data, parity data is generated for each group unit arbitrarily set in the XOR engine 9, and as parity packet data for each group, the wireless control unit 10 to the wireless base station 11, the base station control device 12, It is transmitted to the IP network through gateway 13.

【0024】

On the data receiving side, the data received from the IP network enters the wireless control unit 10 of the mobile phone 1 from the gateway 13, the base station control device 12, and the wireless base station 11, and is arbitrarily set in the XOR engine 9 for each group unit. Check if there is any data missing, and if any data is missing, replay the missing data from the parity data and separate it into audio and image data with the packetizing device 8 and the image data compositing / separating device. It is converted into audio and moving images on an encoder / decoder for audio and image.

【0025】

FIG. 2 is a diagram illustrating data from the operation of the XOR engine unit 9. In Fig. 2, 20 is a group of arbitrarily set IP packets, 21 is parity data generated from a group of IP packets, 22 is an XOR calculator, 23 is a group of IP packets received by the receiving terminal, and 24 is received. The packet data missing in the group in the IP packet, 25 is the reproduced parity packet data group, and 26 is the reproduced IP packet.

【0026】

Next, the operation will be described. Parity data 21 is generated in the XOR engine for each arbitrary group set in the mobile phone 1. The generated parity data is added to the end of a normal IP packet. When the packet data 24 is lost in the IP network 14 due to congestion or the like, the XOR engine reproduces the missing parity data from the other packet data and the parity data, and reproduces a normal packet data group.

【0027】

Figure 3 shows an example in which the data transmission order is changed to increase the resistance to continuous data loss in order to deal with continuous data loss in the radio section. In FIG. 3, 30 is an arbitrary data group that generates parity data, 31 is data whose data transmission order is changed when transmitting, 32 is received data, and 33 is a data string that is continuously missing at the time of reception.

【0028】

Next, the operation will be described. As in Fig. 2, parity data is generated in any group unit, and the data transmission order is changed in any group unit. The data in the data group 30 is divided and transmitted in the XOR engine 9 after changing the data transmission order as shown in 31.

【0029】

When an error occurs in the wireless section of a mobile phone, data is continuously lost. In FIG. 3, the missing data 33 in the received data 32 is continuously generated. When missing data is detected, all the data is played back by waiting for the parity data to be transmitted later and playing back the missing data with the XOR engine. After the data is played back, the data is replaced in the original order and all the data is played back.

【0030】

As described above, according to the present invention, data can be reproduced even when a packet is missing. By limiting the packet exchange range, the effect of delay can be minimized when sending and receiving real-time video.

【0031】

Embodiment 2. Hereinafter, Embodiment 2 of the present invention will be described with reference to the drawings. In FIG. 4, 40 is a PC connected to the Internet, and 41 is an IP telephone connected to the Internet.

【0032】

Next, the operation will be described. The method of transmitting a moving image of a TV telephone and the flow of data are the same as those in the first embodiment. In this embodiment, a method for realizing communication with an existing IP TV telephone on the Internet and an S / W IP TV telephone on a PC will be described. The XOR engine part of the mobile phone is installed in the gateway 13 of the mobile phone network, and when transmitting to the IP network, only the conventional data is transmitted to enable communication with the existing system in the IP network.

【0033】

[Effect of the invention]

In the present invention, the parity data is generated and transmitted in an arbitrary group unit at the time of packet data transmission, so that even if some packet data is lost due to congestion or the influence of the radio section, the missing packet data can be generated. Can be played.

【0034】

In addition, when moving image data is transmitted and received, if it is missing, a clear moving image can be viewed without image distortion due to data complementation or correction.

【0035】

Since the data transmission order is changed, the resistance to continuous loss can be improved.

[Simple explanation of drawings]

[Figure 1]

The block diagram which shows the schematic structure of Embodiment 1 of this invention.

[Figure 2]

The figure for demonstrating the operation concept of the XOR engine part of this invention.

[Fig. 3]

The figure for demonstrating the operation concept of data sorting of this invention.

[Fig. 4]

The block diagram which shows the schematic structure of Embodiment 2 of this invention.

[Fig. 5]

The block diagram which shows the schematic block diagram of the conventional embodiment.

[Fig. 6]

The figure for demonstrating the operation of the conventional embodiment.

[Fig. 7]

The figure for demonstrating the operation of the conventional embodiment. 1 mobile phone, 2 built-in microphone of mobile phone, 3 speakers, 4 encoder / decoder to convert audio data, 5 video camera for TV phone, 6 encoder / decoder to convert image data, 7 audio data and image data synthesis and separation apparatus for synthesizing and separating a packetized eight data device that Tsu bets of, XOR engine to calculate the XOR of the data in 9 any group unit, 10 wireless communication unit, 11 wireless base station, 12 a wireless base station controller Device, 13 Gateway connecting mobile terminal network and IP network, 14 IP network, 20 Arbitrarily set IP packet group, 21 Parity data generated from IP packet group, 22XOR calculator, 23 Received by receiving terminal Group of IP packets, 24 Missing packet data in the group of received IP packets, 25 Reproduced parity packet data group, 26 Reproduced IP packet, 30 Arbitrary data group to generate parity data, 31 Send If the data transmission order is changed, 32 received data, 33 Continuously missing data strings on reception, 40 PCs, 41 IP phones.