Transmission system and method for assigning transmission channel
Abstract
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Expired 3 February 2026, 0.6 years ago.
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11 claims: 5 independent, 6 dependent
- 1中継装置と、前記中継装置を介してデータ通信する通信端末とを有する 伝送システムであって、 前記中継装置は、 前記通信端末から複数の伝送チャネルを介して送信された信号の伝送誤りを検出し、各伝送チャネルにおける伝送誤りの検出結果に関する情報を前記通信端末に送信する送信手段を有し、 前記通信端末は、 複数の外部機器を接続する接続手段と、 前記送信手段により送信された前記情報に基づいて、各伝送チャネルの伝送品質を認識する認識手段と、 前記接続手段に接続する複数の外部機器の夫々から入力された各コンテンツの種類を識別する識別手段と、 前記識別手段により識別した各コンテンツの種類に基づいて、各コンテンツの伝送に要求される伝送品質を判断する判断手段と、 前記認識手段により認識した各伝送チャネルの伝送品質と、前記判断手段により判断した各コンテンツの伝送に要求される伝送品質とに基づいて、前記複数の外部機器の夫々から入力された各コンテンツの伝送に割り当てる伝送チャネルを夫々決定し、前記中継装置に該決定した伝送チャネルの割り当てを要求する要求手段と、 を有することを特徴とする伝送システム。
- 2前記複数の伝送チャネルは、周波数により分けられたチャネルであることを特徴とする請求項1記載の伝送システム。
- 3前記複数の伝送チャネルは、光波長により分けられたチャネルであることを特徴とする請求項1記載の伝送システム。
- 4前記中継装置 は、過去の通信のログから 前記通信端末からの信号の伝送誤りを検出する ことを特徴とする請求項1記載の伝送システム。
- 5前記中継装置 は、 前記通信端末から前記複数の伝送チャネルを介して伝送された伝送品質 測定用パケット の伝送誤りを検出する ことを特徴とする請求項1記載の伝送システム。
- 6前記中継装置は、前記通信端末からの前記 伝送チャネルの割当要求と通信帯域の申請を受け取り、要求された伝送チャネルに空き伝送帯域がある場合に、当該伝送チャネルの割当を行うことを特徴とする請求項1記載の伝送システム。
- 7前記判断手段 は、コンテンツの種類を少なくともリアルタイム性を必要とし伝送帯域が広いコンテンツ、リアルタイム性を必要とし伝送帯域が狭いコンテンツ、リアルタイム性を必要としないコンテンツ、に分類し、該分類に応じて伝送品質を 判断 することを特徴とする請求項1記載の伝送システム。
- 8前記通信端末は、前記識別手段により識別した各コンテンツの種類に基づいて、 コンテンツ毎に通信プロトコルを選択する選択手段を有することを特徴とする請求項 1 記載の伝送システム。
- 9前記要求手段は、 各コンテンツの伝送に割り当てる 伝送レート も 要求することを特徴とする請求項 1 記載の伝送システム。
- 10前記伝送レートは、ピークレートもしくは平均レートを含むことを特徴とする請求項 9 記載の伝送システム。
- 11中継装置と、前記中継装置を介してデータ通信する通信端末とを有する 伝送システムにおける伝送チャネル割当方法であって、 前記中継装置は、 前記通信端末から複数の伝送チャネルを介して伝送された信号の伝送誤りを検出し、各伝送チャネルにおける伝送誤りの検出結果に関する情報を前記通信端末に送信する送信工程を実行し、 前記通信端末は、 前記送信工程において送信された前記情報に基づいて、各伝送チャネルの伝送品質を認識する認識工程と、 前記通信端末に接続する複数の外部機器の夫々から入力された各コンテンツの種類を識別する識別工程と、 前記識別工程において識別した各コンテンツの種類に基づいて、各コンテンツの伝送に要求される伝送品質を判断する判断工程と、 前記認識工程において認識した各伝送チャネルの伝送品質と、前記判断工程において判断した各コンテンツの伝送に要求される伝送品質とに基づいて、前記複数の外部機器の夫々から入力された各コンテンツの伝送に割り当てる伝送チャネルを夫々決定し、前記中継装置に該決定した伝送チャネルの割り当てを要求する要求工程と、 を 実行する ことを特徴とする伝送チャネル割当方法。
Independent claims11
71 paragraphs, as filed
The present invention relates to a technique for ensuring transmission quality in a transmission system.
Currently, terrestrial digital broadcasting services have started, and the television system is shifting from SDTV to higher-definition HDTV. SDTV is an abbreviation for Standard Definition Television and HDTV is an abbreviation for High Definition Television. In addition, there are increasing opportunities to handle HD video at home, such as the sale of low-priced general-purpose HD (High Definition) cameras. Then, there is a request to store digital broadcast contents and HD camera images in a storage device so that the family can share them at home, and to watch the contents and HD images from each person's PC (Personal Computer) at any time. .. Therefore, in order to access the storage device that stores contents and HD images from each person's PC, a network is arranged in the home.
As a home network (home network), a wired LAN (Local Area Network) such as Ethernet (registered trademark) and a wireless LAN specified by IEEE 802.11x are currently used. Usually, wired LAN takes time and effort to arrange cables in the home, so there is a high demand for configuring a home network with wireless LAN.
However, since the transmission band of wireless LAN is not as large as that of wired LAN, when sending HD video, transmission errors frequently occur due to delays and radio wave interference due to the influence of other traffic. Since this transmission error occurs in principle and cannot be prevented, the packet lost due to the transmission error is usually retransmitted. However, in the case of content such as HD moving images, which has a wide transmission band and requires real-time performance, the retransmission process is not completed within the time required for displaying the moving image, and the video cannot be displayed without interruption.
As a method for suppressing the occurrence of a transmission error, there is a method of increasing the transmission power (for example, Patent Document 1).<patcit num="1"><text>JP-A-2002-95065</text></patcit>
<p> However, if the transmission power is increased, there is a problem that it interferes with other wireless communications within the same frequency.</p><p> An object of the present invention is to effectively utilize the communication bands of a plurality of transmission channels to transmit contents.</p>
<p> The present invention<u style="single">It has a relay device and a communication terminal for data communication via the relay device.</u>It s a transmission system,<u style="single">The relay device has a transmission means for detecting a transmission error of a signal transmitted from the communication terminal via a plurality of transmission channels and transmitting information regarding a detection result of the transmission error in each transmission channel to the communication terminal. The communication terminal includes a connecting means for connecting a plurality of external devices, a recognizing means for recognizing the transmission quality of each transmission channel based on the information transmitted by the transmitting means, and a plurality of connecting means for connecting to the connecting means. An identification means for identifying the type of each content input from each of the external devices of the above, and a determination means for determining the transmission quality required for transmission of each content based on the type of each content identified by the identification means. , The transmission quality of each content input from each of the plurality of external devices based on the transmission quality of each transmission channel recognized by the recognition means and the transmission quality required for the transmission of each content determined by the determination means. A requesting means for determining each transmission channel to be assigned to transmission and requesting the relay device to allocate the determined transmission channel, and</u>It is characterized by having.</p><p> In addition, the present invention<u style="single">It has a relay device and a communication terminal for data communication via the relay device.</u>A transmission channel allocation method in a transmission system.<u style="single">The relay device executes a transmission step of detecting a transmission error of a signal transmitted from the communication terminal via a plurality of transmission channels and transmitting information regarding a detection result of the transmission error in each transmission channel to the communication terminal. The communication terminal has a recognition step of recognizing the transmission quality of each transmission channel based on the information transmitted in the transmission step, and each content input from each of a plurality of external devices connected to the communication terminal. The identification step for identifying the type of the content, the determination step for determining the transmission quality required for the transmission of each content based on the type of each content identified in the identification step, and the transmission channel recognized in the recognition step. Based on the transmission quality and the transmission quality required for the transmission of each content determined in the determination process, the transmission channels to be assigned to the transmission of each content input from each of the plurality of external devices are determined, respectively. A requesting process for requesting the relay device to allocate the determined transmission channel, and</u>To<u style="single">Run</u>It is characterized by that.</p>
<p> According to the present invention<u style="single">When a plurality of external devices are connected to a communication terminal and content from each external device is transmitted via a relay device, the communication terminal determines the transmission quality (reception quality) of each transmission channel in the relay device and each external device. Since the transmission channel to be assigned to each content is determined according to the type of each content from and the relay device is requested to allocate the determined transmission channel, a plurality of transmission channels from a plurality of external devices connected to the communication terminal are requested. Content can be transmitted efficiently, and limited transmission channels can be used effectively.</u>it can.</p>
Hereinafter, the best mode for carrying out the invention will be described in detail with reference to the drawings.
[Multiple transmission system] First, the network configuration of the multiplex transmission system will be described with reference to FIG. FIG. 1 is a diagram showing an example of a network configuration of a multiplex transmission system. In FIG. 1, 201 is an access point having a wireless LAN function defined by IEEE 802.11x, and relays wireless communication between a plurality of wireless terminals. The access point 201 operates like a 3 × 3 switch, converts the input signals of frequencies f1, f2, and f3 into arbitrary frequencies and outputs them. In addition, it manages the traffic and bandwidth of the entire network, and the wireless terminal obtains the transmission right and communicates according to the instruction of the access point 201.
202 to 210 are wireless terminals, respectively, and connect various devices such as HD camera 213, telephone 212, 214, SD camera 215, PC216, and 217 by wireless signals. Here, each wireless terminal 202 to 210 is equipped with a transmitting unit (FIG. 2) and a receiving unit (FIG. 3), and any connected device is connected to each.
Here, the wireless terminal 202 is connected to the television 211 and the telephone 212, the wireless terminal 203 is connected to the HD camera 213, the telephone 214, the SD camera 215, and the PC 216, and the wireless terminal 204 is connected to the PC 217. And. Further, it is assumed that devices such as a camera and a PC (not shown) are connected to the wireless terminals 205 to 210.
[Configuration of wireless terminal] Next, the transmitter and receiver configurations of the wireless terminals 202 to 210 described above will be described in order with reference to FIGS. 2 and 3. Here, it is assumed that the wireless terminal has both a transmitting unit and a receiving unit, and the transmitting unit is connected to a camera, a telephone, a PC, etc., and information such as video, audio, and data is input from each device.
FIG. 2 is a diagram showing an example of the configuration of the transmission unit of the wireless terminal in the present embodiment. As shown in FIG. 2, there are four inputs, and four pieces of information from # 1, # 2, # 3, and # 4 are input to the devices I / F 315 to 318. The devices I / F 315 to 318 convert the information input from each connected device into a certain signal format and send it to the content type recognition unit 301. The content type recognition unit 301 identifies whether the input information is video, audio, or data, and further determines the required transmission band, the presence or absence of real-time performance, and the like.
That is, the content type recognition unit 301 classifies the input information into the following three types, for example. Video information that requires real-time performance over a wide band such as HD video (video 1) Stream data (video 2 and audio) that requires real-time performance with a relatively narrow bandwidth such as Internet telephone and video / audio distribution Data (data) that does not tolerate transmission errors such as data communication, and in the event of an error, it is necessary to retransmit information and reliably transmit all information.
Here, the above-mentioned # 1 is classified as video 1, # 2 is classified as video 2, # 3 is classified as audio, and # 4 is classified as data, and the classification information is notified to the band management unit 305. Note that this classification information may be notified to the band management unit 305 from a device connected in advance, instead of being discriminated from the information input by the content type recognition unit 301. In that case, the classification information is determined in advance according to the connected device.
Next, the multiplexing / switching unit 302 inputs the video 1, video 2, audio, and data information recognized by the content type recognition unit 301, respectively, and multiplexes the same type of information. Further, the multiplex switch unit 302 is composed of 5 × 3 switches, and can output the input information to an arbitrary output terminal. That is, since the video 2 and audio input from IN2 and IN3 out of the five inputs (IN1 to IN5) are the same type of information, these are multiplexed and output to the output terminal OUT2. Further, the video 1 input from IN1 is output to the output terminal OUT1, and the data input from IN4 is output to the output terminal OUT3, and is passed to the protocol selection / processing unit 303. The input terminal IN5 will be described in detail together with a description of the transmission quality recognition unit 304 described later.
Next, the protocol selection / processing unit 303 selects a protocol required for the input information and performs the processing. For example, for video that requires real-time performance over a wide band, such as HD video, processing is performed by applying a protocol such as UDP (User Datagram Protocol). In addition, protocols such as RTP (Real-time Transport Protocol) are applied to data streams that have a relatively narrow bandwidth and require real-time performance, such as Internet telephones and video / audio distribution. In addition, protocols such as TCP (Transmission Control Protocol) are applied to communications that do not tolerate transmission errors, such as data communications, and that need to retransmit information and reliably transmit all information in the event of an error. To process. In addition, IP (Internet Protocol) or MAC (Media Access Control) processing may be performed as those lower layer protocols.
Specifically, UDP / MAC is processed for video 1, RTP / UDP / MAC is processed for video 2 and audio, and TCP / MAC is processed for data. Next, the signal subjected to the above-mentioned protocol processing is encoded by the coding / modulation units 306 to 308 such as scrambling and modulated corresponding to various wireless methods. Then, the RF units 309 to 311 set the signals from the code / modulation units 306 to 308 to arbitrary frequencies f1 to f3 under the control of the transmission quality recognition unit 304, and transmit each signal as a radio signal from the antennas 312 to 314. To do.
Further, the transmission quality recognition unit 304 periodically generates a transmission quality check packet and outputs it to the input terminal IN5 of the multiplexing switch unit 302 in order to check the transmission quality of the available transmission channel (frequency channel). Then, the packets output from the output terminals OUT1, OUT2, and OUT3 of the multiplex / switch unit 302 pass through the protocol selection / processing unit 303, the code / modulation unit 306 to 308, the RF unit 309 to 311, and the antenna 312 to 314. Each is sent.
On the other hand, the above-mentioned transmission quality check packet is sent to the access point 201 that manages the transmission quality of the wireless network. Here, the access point 201 receives those packets, detects a transmission error by calculating the error detection code added to the packet, and returns the detection result to the transmitting terminal. Then, the transmitting terminal receives the packet including the detection result by the receiving unit, notifies the transmission quality recognition unit 304, and recognizes which frequency band the error rate is good. Here, for example, if the error rates are good in the order of frequencies f1, f2, and f3, the frequency of the RF unit 309 through which the video 1 is transmitted is set to f1. Similarly, the RF unit 310 is set to f2 and the RF unit 311 is set to f3.
Instead of sending the transmission quality check packet from the transmission quality recognition unit 304, the error information may be sent back to the transmission terminal from the transmission quality history of the packet in the past communication to judge the transmission quality.
Further, instead of periodically sending the transmission quality check packet, the transmission quality may be detected by appropriately transmitting the packet before the start of communication.
Further, the access point 201 also manages the communication band of the wireless network, determines whether or not there is an empty band in response to the communication request from the transmitting terminal, and notifies the band management unit 305 of the transmitting terminal of the determination result. Then, the band management unit 305 controls the connected device based on the determination result.
FIG. 3 is a diagram showing an example of the configuration of the receiving unit of the wireless terminal in the present embodiment. As shown in FIG. 3, the antennas 401 to 403 receive radio signals of frequencies f1, f2, and f3 transmitted from the transmitting terminal, respectively. Here, it is described as being different from the antennas 312 to 314 of the transmitting unit, but usually the transmitting antenna and the receiving antenna are shared.
RF units 404 to 406 are set to receive signals of frequencies f1, f2, and f3, and take out signals from the radio signals. The demodulation / decoding units 407 to 409 demodulate / decode the coded / modulated signal and output it to the protocol processing unit 410. The protocol processing unit 410 performs protocol processing of the input signal. Here, UDP / MAC processing is performed for video 1 of frequency channel f1, RTP / UDP / MAC processing is performed for video 2 and audio of frequency channel f2, and data of frequency channel f3 is processed. TCP / MAC processing is performed.
Next, the signal from which the protocol processing has been performed is output to the switch unit 411. This switch unit 411 is composed of, for example, a 3 × 4 switch, and outputs signals input to the input terminals IN1, IN2, and IN3 to arbitrary output terminals OUT1 to OUT4. Then, the signals output to the output terminals OUT1 to OUT3 are sent to the TV, telephone, and PC connected via the devices I / F412 to 414. Further, the management packet transmitted from the access point 201 is output to the output terminal OUT4 according to the transmission quality check packet sent from the transmission terminal, and is sent to the transmission quality recognition unit 304 or the band management unit 305.
[Access Point Configuration] Next, the configuration of the access point 201 shown in FIG. 1 will be described with reference to FIG. FIG. 4 is a diagram showing an example of the configuration of the access point in the present embodiment. As shown in FIG. 4, the antennas 501 to 503 send and receive radio signals having frequencies f1, f2, and f3, respectively.
RF units 504 to 506 are set to receive signals of frequencies f1, f2, and f3, and take out signals from the radio signals. The demodulation / decoding units 510 to 512 demodulate / decode the coded / modulated signal and output it to the protocol processing unit 513. The protocol processing unit 513 performs protocol processing of the input signal.
Next, the signal from which the protocol processing has been performed is output to the switch unit 514. This switch unit 514 is composed of, for example, a 4 × 4 switch, and outputs signals input to the input terminals IN1, IN2, IN3, and IN4 to arbitrary output terminals OUT1 to OUT4. Here, the signals output to the output terminals OUT1 to OUT3 are coded and modulated by the code / modulation units 516 to 518 after the protocol processing is performed by the protocol processing unit 515. The RF units 507 to 509 set the signals from the code / modulation units 516 to 518 to frequencies f1, f2, and f3, respectively, and transmit the respective signals from the antennas 501 to 503 as radio signals. In addition, the transmission quality check packet sent from the transmitting terminal is output from the output terminal OUT4 and sent to the network management unit 519.
The network management unit 519 receives the transmission quality check packet sent periodically from the transmitting terminal, detects the transmission error by calculating the error detection code attached to the packet, and measures the error rate. To do. Then, a management packet including error rate information is generated and output to the input terminal IN4 of the switch unit 514, and the management packet is output from the output terminals OUT1, OUT2, and OUT3, respectively. This management packet is sent to the transmission quality recognition unit 304 of the transmission terminal that transmitted the transmission quality check packet via the protocol processing unit 515, the code / modulation unit 516 to 518, the RF units 507 to 509, and the antenna 501 to 503. .. Then, the transmitting terminal that receives the management packet on different frequency channels recognizes the error rate of the frequency channel.
The access point 201 also manages the communication band of the wireless network, determines whether or not there is an empty band in response to the communication request from the transmitting terminal, and notifies the band management unit 305 of the transmitting terminal of the determination result. To do. Then, the band management unit 305 performs the connection device based on the determination result.
Although the transmission quality control and the band management will be described as being performed by the access point 201, a specific wireless terminal may manage them.
Further, although the transmission quality check packet is transmitted from the wireless terminal to the access point, it may be transmitted from the access point to the wireless terminal, the wireless terminal measures the error rate, and the result is notified to the access point.
[Transmission channel allocation process] Next, using FIG. 1, in a multiplex transmission system, the transmission quality is guaranteed for each transmission channel between the access point 201 and the wireless terminals 202 to 210, and transmission is performed according to the type of content. The process of allocating channels will be described.
Here, a case where video, audio, and data are communicated with a plurality of wireless terminals 202 to 204 via the access point 201 will be described as an example. Specifically, the following three communications shall be performed. -Distribute camera images from HD camera 213 and SD camera 215 connected to wireless terminal 203 to TV 211 connected to wireless terminal 202-Connect to telephone 214 connected to wireless terminal 203 and wireless terminal 202 Calls to and from the telephone 212 Data is transferred from the PC 216 connected to the wireless terminal 203 to the PC 217 connected to the wireless terminal 204.
First, when the wireless terminal 203 communicates, the access point 201 is requested to allocate a frequency channel. Note that transmission quality check packets are periodically transmitted and received between the plurality of wireless terminals and the access point 201 using all frequency channels f1 to f3, and the transmission quality of any channel is good from the calculated error rate. It is assumed that you are aware of this.
Generally, in wireless communication, the influence on transmission quality differs depending on the frequency due to the condition of the building, interference with external radio waves, and the like. Further, since the transmission quality is not always constant and fluctuates, the wireless terminal 203 updates the ranking of the frequency and the transmission quality every time the error rate information arrives from the access point 201. Here, it is assumed that the transmission quality when communication is desired is best at frequency f1, becomes worse in the order of frequency f2 and frequency f3, and the packet loss rate becomes higher.
That is, in the present embodiment, the access point 201 monitors the error rate of the frequency channels f1 to f3, and assigns the frequency channels f1 to f3 as the transmission quality assurance levels 1 to 3 as shown in FIG.
Next, according to the transmission quality assurance level, the wireless terminal 203 sets the video 1 from the HD camera 213 to the frequency f1, the transmission band to 25 Mbps, the audio from the telephone 214 to the frequency f2, and the transmission band to 1 Mbps. Further, the video 2 from the SD camera 215 is set to the frequency f2, the transmission band is set to 5 Mbps, and the data from the PC 216 is set to the frequency f3. Then, the information is transmitted to the access point 201 together with the source address and the destination address.
At this time, the transmission band is applied at the peak rate for video 1 and at the average rate for audio and video 2. The packet in which the information is described is input from the transmission quality recognition unit 304 to the input terminal IN5 of the multiplexing switch unit 302, and is output from the management packet transmission channel, for example, the output terminal OUT3 corresponding to the frequency f3. Then, it is transmitted via the protocol processing unit 303, the code / modulation unit 308, the RF unit 311 and the antenna 314.
On the other hand, the transmitted packet is received by the antenna 503 of the access point 201 and transmitted to the network management unit 519 via the RF unit 506, the demodulation / decoding unit 512, the protocol processing unit 513, and the switch unit 514. The network management unit 519 manages the communication band of the channel through which video 1, audio, and video 2, which require at least real-time performance, are transmitted. Also, when a packet is received from the transmitting terminal, the free band of the wireless network is checked, and if the band is free, communication permission is given, and if the band is insufficient, a reply packet is sent so as not to give communication permission. Send it back to the terminal.
Here, when the bandwidth is free, the network management unit 519 generates a management packet including communication permission information and outputs it to the input terminal IN4 of the switch unit 514. Then, the management packet is output to the output terminal OUT3 corresponding to the frequency f3, which is a channel for managing the management packet, and is transmitted via the protocol processing unit 515, the code / modulation unit 518, the RF unit 509, and the antenna 503. To. Further, the transmitted management packet is received by the antenna 403 of the transmitting terminal 203 and transmitted to the band management unit 305 via the RF unit 406, the demodulation / decoding unit 409, the protocol processing unit 410, and the switch unit 411.
Next, when the transmitting terminal 203 receives the communication permission information from the access point 201, the transmitting terminal 203 can transmit the information from the connected devices 213 to 216. When transmitting, the video 1 from the HD camera 213 is input from the input terminal # 1 of the content type recognition unit 301, and the sound from the telephone 214 is input from the input terminal # 2 of the content type recognition unit 301. In addition, the video 2 from the SD camera 215 is input from the input terminal # 3, and the data from the PC 216 is input from the input terminal # 4. These four pieces of information are output to the devices I / F 315 to 318, converted into a certain signal format, and output to the content type recognition unit 301.
The content type recognition unit 301 determines the type of input information, the transmission band, and the presence or absence of real-time performance. Here, it is assumed that the information is directly transmitted to the band management unit 305 directly from the connected device in advance. Output to the multiplex switch section 302 as it is. The multiplexing / switching unit 302 inputs video 1, video 2, audio, and data information from the content type recognition unit 301, respectively, and multiplexes the same type of information. Of the four inputs (IN1, IN2, IN3, IN4), the audio and video 2 input from IN2 and IN3 are of the same type of information, so these are multiplexed and output to the output terminal OUT2. Further, the video 1 input from IN1 is output to the output terminal OUT1, and the data input from IN4 is output to the output terminal OUT3, respectively.
Next, the protocol selection / processing unit 303 selects the protocol required for the input information and performs the processing. That is, UDP / MAC is applied to video 1, RTP / UDP / MAC is applied to video 2 and audio, and TCP / MAC is applied to data for processing. The signals subjected to these protocol processing are coded by the coding / modulation units 306 to 308 and modulated according to various wireless methods such as scrambling. Then, RF units 309 to 311 set the signals from the code / modulation units 306 to 308 to the frequencies f1 to f3 assigned under the control of the transmission quality recognition unit 304.
Here, the RF unit 309 through which the video 1 that requires the most transmission quality is transmitted is set to the frequency f1. Next, the RF unit 310 in which the audio and video 2 that require transmission quality are transmitted is set to the frequency f2. Further, even if the transmission quality is poor, the RF unit 311 that transmits data whose transmission quality can be guaranteed by the TCP protocol is set to the frequency f3. Then, the video 1, video 2, audio, and data signals are transmitted as wireless signals from the antennas 312 to 314 at the set frequencies f1 to f3.
It should be noted that the signal of frequency f3 does not start communication according to the instruction from the band management unit 305, but performs carrier sense and transmits it when frequency f3 is not used.
On the other hand, the radio signal transmitted from the transmitting terminal 203 is received by the antennas 501 to 503 of the access point 201, and the signals of frequencies f1, f2, and f3 are taken out by the RF units 504 to 506, respectively. The demodulation / decoding units 510 to 512 demodulate / decode the coded / modulated signal and output it to the protocol processing unit 513. The protocol processing unit 513 performs protocol processing of the input signal. The switch unit 514 outputs the signals input from the input terminals IN1, IN2, and IN3 to the destination output terminals OUT1 to OUT3. The signals output to the output terminals OUT1 to OUT3 are protocol-processed by the protocol processing unit 515, and encoded / modulated by the coding / modulation units 516 to 518. The RF units 507 to 509 set the signals from the code / modulation units 516 to 518 to frequencies f1 to f3, respectively, and transmit the respective signals from the antennas 501 to 503 as radio signals. Here, the transmitted signals of frequencies f1 and f2 are transmitted to the wireless terminal 202, and the signals of frequencies f3 are transmitted to the wireless terminal 204.
As a result, the signals of frequencies f1 and f2 are received by the antennas 401 and 402 of the wireless terminal 202, and the signals are taken out by the RF units 404 and 405. These signals are demodulated / decoded by the demodulation / decoding units 407 and 408, and output to the protocol selection / processing unit 410. The protocol selection / processing unit 410 determines the protocol to be applied to the input signal and performs the processing.
Here, UDP / MAC processing is performed on the video 1 from the frequency channel f1, and RTP / UDP / MAC processing is performed on the video 2 and the audio from the frequency channel f2. The signal for which protocol processing has been performed is output to the multiplexing switch section 411.
The multiplex switch section 411 outputs the input signal to the output terminal to which the device to be connected is connected. In this example, it is assumed that the television 211 is connected to the output terminal OUT2 and the telephone 212 is connected to the output terminal OUT3. Therefore, the signal of the video 1 input from the input terminal IN1 is output to the output terminal OUT2 and sent to the television 211 to display the video 1. In addition, the audio and video 2 signals input from the input terminal IN2 are separated, the audio is sent to the telephone 212 connected to the output terminal OUT3, and the video 2 is sent to the television 211 connected to the output terminal OUT2. ..
Since the output ends of video 1 and video 2 are the same, it is assumed that the user switches so that one of them is displayed.
Further, since the voice of the telephone 212 is returned to the telephone 214 connected to the wireless terminal 203, the voice of the telephone 212 is similarly transmitted to the wireless terminal 203 side using the frequency f2 to make a call.
On the other hand, the data sent from the wireless terminal 203 at the frequency f3 is relayed by the access point 201, received by the antenna 403 of the wireless terminal 204, and the signal is taken out by the RF unit 406. This signal is demodulated / decoded by the demodulation / decoding unit 409 and output to the protocol selection / processing unit 410. This protocol selection / processing unit 410 determines the protocol to be applied to the input signal, and performs TCP / MAC processing. The signal for which protocol processing has been performed is output to the multiplexing switch section 411. In this example, since the PC217 is connected to the output terminal OUT2, the data input from the input terminal IN3 is output to the output terminal OUT2 and sent to the PC217.
In the present embodiment, the communication between the wireless terminals 202 to 204 is described as an example, but the wireless terminals 205 to 210 may also perform communication such as video 1, audio, and video 2. In that case, it is assumed that the network management unit 519 of the access point 201 grants communication permission up to the upper limit of the entire communication band.
FIG. 6 is a diagram showing a state in which a plurality of pieces of information are multiplexed and transmitted between the access point and the plurality of wireless terminals. In the example shown in FIG. 6, high-definition images 1 and 2 are communicated at frequency f1, video 1 to 5 and control data are communicated at frequency f2, and data 1 to 3 are communicated at frequency f3. It is in a state of being.
In addition, congestion may occur in the switch unit 514 depending on the type of content. Since the transmission band is allocated to the audio and video 2 at the average rate, if the buffer in the switch section 514 cannot be retained momentarily beyond the entire communication band, part of the data will be discarded. .. On the other hand, since the transmission band is allocated to the video 1 at the peak rate, the entire communication band is not instantaneously exceeded and the transmission quality is maintained.
It is assumed that an error occurs in each transmission channel in this communication state. In the transmission channel of frequency f1, data is lost in bit or packet units due to a bit error that rarely occurs, but if the bit is missing, the error is not noticeable to the human eye. Further, even if the packet unit is missing, the HD image can be displayed without impairing the image quality by image correction or the like. In addition, the transmission channel with frequency f2 causes noise in the audio and visible distortion of the image due to a large number of bit errors. Such transmission quality is acceptable because it is the same in the current telephone and television broadcasting. It is assumed that the transmission channel of frequency f3 causes many bit errors and burst-like errors. However, since the data uses the TCP protocol, it is retransmitted many times until the data arrives correctly, and by transmitting over time, high-quality communication can be performed.
In this way, optimal communication can be performed by selecting the transmission channel and protocol according to the type of content. In addition, since it is required to allocate a transmission channel according to the status of the transmission channel and the type of content, optimum transmission can be performed in an actual environment. In addition, the limited transmission channel can be effectively used, and a large number of users can simultaneously communicate with the required communication quality.
Although wireless communication has been described as an example in the present embodiment, the present invention is not limited to this, and can be applied to optical communication as well. For example, the present invention can be applied to optical wavelength division multiplexing in which multiple optical wavelengths are used to multiplex and transmit in an optical fiber.
Since the loss and dispersion of an optical fiber differ depending on the optical wavelength, the error rate differs depending on the wavelength when the same distance is transmitted. In addition, optical components have a shorter life than electrical components, and their characteristics change significantly with temperature, so that the transmission quality of a transmission channel using a specific optical wavelength may deteriorate. If the present invention is applied to such a system as well, optimum communication can be performed according to the content.
Even if the present invention is applied to a system composed of a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), the present invention may be applied to a device consisting of one device (for example, a copying machine, a facsimile machine, etc.). It may be applied.
Further, a recording medium in which the program code of the software that realizes the functions of the above-described embodiment is recorded is supplied to the system or the device, and the computer (CPU or MPU) of the system or the device stores the program code in the recording medium. Read and execute. Needless to say, this also achieves the object of the present invention.
In this case, the program code itself read from the recording medium realizes the function of the above-described embodiment, and the recording medium storing the program code constitutes the present invention.
As a recording medium for supplying this program code, for example, a floppy (registered trademark) disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a non-volatile memory card, a ROM, or the like is used. be able to.
Further, it goes without saying that by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also the following cases are included. That is, when the OS (operating system) or the like running on the computer performs a part or all of the actual processing based on the instruction of the program code, and the function of the above-described embodiment is realized by the processing.
Further, the program code read from the recording medium is written in the memory provided in the function expansion board inserted in the computer or the function expansion unit connected to the computer. After that, based on the instruction of the program code, the function expansion board, the CPU provided in the function expansion unit, etc. perform a part or all of the actual processing, and the processing includes the case where the function of the above-described embodiment is realized. Needless to say.
<figref num="1">It is a figure which shows an example of the network configuration of a multiplex transmission system.</figref><figref num="2">It is a figure which shows an example of the structure of the transmission part of the wireless terminal in this embodiment.</figref><figref num="3">It is a figure which shows an example of the structure of the receiving part of the wireless terminal in this embodiment.</figref><figref num="4">It is a figure which shows an example of the structure of the access point in this embodiment.</figref><figref num="5">It is a figure which shows the relationship between the transmission quality assurance level and a frequency channel in this embodiment.</figref><figref num="6">It is a figure which shows the state which a plurality of information are multiplexed and transmitted between an access point and a plurality of wireless terminals.</figref>
Code description
201 Access point 202 Wireless terminal 203 Wireless terminal 204 Wireless terminal 205 Wireless terminal 206 Wireless terminal 210 Wireless terminal 211 TV 212 Phone 213 HD camera 214 Phone 215 SD camera 216 PC217 PC301 Content type recognition unit 302 Multiplexing / switching unit 303 Protocol selection / processing Part 304 Transmission quality recognition part 305 Band management part 306 Code / modulation part 307 Code / modulation part 308 Code / modulation part 309 RF part 310 RF part 311 RF part 312 Antenna 313 Antenna 314 Antenna 315 Equipment I / F316 Equipment I / F317 Equipment I / F318 Device I / F401 Antenna 402 Antenna 403 Antenna 404 RF section 405 RF section 406 RF section 407 Demodition / decoding section 408 Demodition / decoding section 409 Demodulation / decoding section 410 Protocol processing section 411 Switch section 412 Device I / F413 Device I / F414 Equipment I / F501 Antenna 502 Antenna 503 Antenna 504 RF part 505 RF part 506 RF section 507 RF section 508 RF section 509 RF section 510 Demodulation / decoding section 511 Demodulation / decoding section 512 Demodulation / decoding section 513 Protocol processing section 514 Switch section 515 Protocol processing section 516 Code / modulation section 517 Code / modulation section 518 Code Modulation unit 519 Network management unit
Every citation, both ways
| Document | Relation | Office |
|---|---|---|
| WO2004095851A1 | Cites | World Intellectual Property Organization (WIPO) |
| JP10257097A | Cites | Japan |
| JP09037339A | Cites | Japan |
| JP2005236416A | Cites | Japan |
| JP2001507895A | Cites | Japan |
5 members in 3 offices
Priority claims2
| Document | Office | Kind | Date |
|---|---|---|---|
| 2006027711 | Japan | A | |
| JP20060027711 | – | – | – |
Members5
| Document | Office | Kind | |
|---|---|---|---|
| WO2007088993A1 | World Intellectual Property Organization (WIPO) | A1 | |
| JP2007208853A | Japan | A | |
| JP4137130B2This record | Japan | B2 | |
| US2009064250A1 | United States of America | A1 | |
| US7796635B2 | United States of America | B2 |
12 legal events, as the office reported them to INPADOC
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Numbers
- Publication
- 4137130
- Publication, DOCDB
- 4137130
- Publication, EPODOC
- JP4137130B
- Application
- 27711
- Application, DOCDB
- 2006027711
- Application, EPODOC
- JP20060027711
Titles2
- Japanese
- 伝送システム及び伝送チャネル割当方法
- English
- Transmission system and transmission channel allocation method
Classification
- CPC, 20
- H04L1/0018
- H04W72/563
- H04L1/0026
- H04L12/2803
- H04L12/2827
- H04L12/2834
- H04L12/2836
- H04L2001/0093
- H04L2012/2841
- H04L2012/2845
- H04L2012/2849
- H04N21/2385
- H04N21/26216
- H04N21/43637
- H04N21/631
- H04N21/64707
- H04L67/125
- H04L69/40
- H04L69/14
- H04W72/54
- IPC, 10
- H04L12 28
- G06F13 00
- H04N7 173
- H04N21 4363
- H04W4 06
- H04W72 04
- H04W72 06
- H04W72 08
- H04W72 10
- H04W84 12