Communication control method
Abstract
[Task] When serial transmission of isochronous data and non-ichronous data is mixed and communication is performed through a transmission line with a high transmission error rate, there is a problem that the image during streaming playback is distorted or noise is mixed in the voice. there were.
Solution.When the isochronous data is received in error, the non-isochronous region is used to retransmit the data. As a result, transmission errors of isochronous data can be reduced without impairing the isochronism.

Term
Term ended
Projected expiry passed 4 October 2021, 5 years ago.
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23 claims: 4 independent, 19 dependent
- 1【特許請求の範囲】 【請求項1】 複数の端末を互いに接続してなるネットワーク上において、等時性が要求されるアイソクロナスデータと、そうでない非アイソクロナスデータとを混在させてシリアル伝送するべく各端末の通信を制御する方法であって、 時間をサイクルに区切って、1つ1つのサイクル内に、アイソクロナス領域と、非アイソクロナス領域とを設け、 1つ1つのサイクル内で各端末が前記アイソクロナス領域を時分割的に利用してアイソクロナスデータを送信した後、送信先の端末によって当該アイソクロナスデータがエラーなく受信されたか否かを判定し、 アイソクロナスデータをエラー受信した端末が存在する場合、当該アイソクロナスデータの送信元である端末に命じて、前記非アイソクロナス領域を利用して当該アイソクロナスデータを再送させることを特徴とする、通信制御方法。
- 2【請求項2】 各端末がアイソクロナスデータに誤り検出符号を付加して送信し、かつ送信先の端末が当該アイソクロナスデータを受信して誤り検出符号を検査する場合、当該検査の結果を受けて、前記判定を行うことを特徴とする、請求項1に記載の通信制御方法。
- 3【請求項3】 各端末がアイソクロナスデータをブロックに分割して送信する場合、ブロック単位で前記判定を行い、かつブロック単位で前記再送を行わせることを特徴とする、請求項1に記載の通信制御方法。
- 4【請求項4】 アイソクロナスデータをエラー受信した端末が複数存在する場合、当該アイソクロナスデータの送信元である各端末に対して、当該各端末が非アイソクロナス領域を時分割的に利用してアイソクロナスデータを再送するように、順次的に再送を指示することを特徴とする、請求項1に記載の通信制御方法。
- 5【請求項5】 アイソクロナスデータをエラー受信した端末が複数存在する場合、当該アイソクロナスデータの送信元である各端末に対して、当該各端末が非アイソクロナス領域を時分割的に利用してアイソクロナスデータを再送するように、それぞれの送信時刻を一括的に通知することを特徴とする、請求項1に記載の通信制御方法。
- 6【請求項6】 各端末がアイソクロナスデータを変調して送信する場合、変調方式を変更させた上で前記再送を行わせることを特徴とする、請求項1に記載の通信制御方法。
- 7【請求項7】 各端末がアイソクロナスデータを符号化して送信する場合、符号化率を変更させた上で前記再送を行わせることを特徴とする、請求項1に記載の通信制御方法。
- 8【請求項8】 各端末がアイソクロナスデータを符号化および変調して送信する場合、変調方式および符号化率を変更させた上で前記再送を行わせることを特徴とする、請求項1に記載の通信制御方法。
- 9【請求項9】 各端末がそれぞれ特定のグループに属する複数の端末を送信先としてアイソクロナスデータをマルチキャスト送信する場合、 送信先のグループに属する全ての端末によってアイソクロナスデータがエラーなく受信されたか否かを判定し、 当該グループ内にアイソクロナスデータをエラー受信した端末が1つでも存在すれば、当該グループ内の全ての端末を送信先として当該アイソクロナスデータをマルチキャスト再送させることを特徴とする、請求項1に記載の通信制御方法。
- 10【請求項10】 各端末がそれぞれ他の全ての端末を送信先としてアイソクロナスデータをブロードキャスト送信する場合、 送信先の全ての端末によって当該アイソクロナスデータがエラーなく受信されたか否かを判定し、 アイソクロナスデータをエラー受信した端末が1つでも存在すれば、全ての端末を送信先として当該アイソクロナスデータをブロードキャスト再送させることを特徴とする、請求項1に記載の通信制御方法。
- 11【請求項11】 1つ1つのサイクルにおいて各端末が前記アイソクロナス領域を時分割的に利用してそれぞれアイソクロナスデータを送信するように、当該アイソクロナス領域を多分割してその1つ1つを専用領域として各端末に割り当て、かつ、当該専用領域に関する情報を先頭サイクルの開始前に各端末に通知しておくことを特徴とする、請求項1に記載の通信制御方法。
- 12【請求項12】 1つ1つのサイクルにおいて各端末が前記アイソクロナス領域を時分割的に利用してそれぞれアイソクロナスデータを送信するように、当該アイソクロナス領域を多分割してその1つ1つを専用領域として各端末に割り当てておき、かつ、1つ1つのサイクルにおいて当該専用領域と対応する時刻に各端末に対して順次的に送信を指示することを特徴とする、請求項1に記載の通信制御方法。
- 13【請求項13】 送信先の端末にアイソクロナスデータをエラーなく受信したか否かを問い合わせ、その応答を受けて前記判定を行うことを特徴とする、請求項1に記載の通信制御方法。
- 14【請求項14】 送信先の端末から自発的に、アイソクロナスデータをエラーなく受信したか否かが応答されるのを受けて、前記判定を行うことを特徴とする、請求項1に記載の通信制御方法。
- 15【請求項15】 再送されたアイソクロナスデータが再びエラー受信された場合、エラー受信が解消されるまで当該アイソクロナスデータを繰り返し再送させることを特徴とする、請求項1に記載の通信制御方法。
- 16【請求項16】 1つ1つのサイクルにおいてアイソクロナスデータの再送に費やすことができる時間の最大値が決められており、もう1回再送を実行すると再送に費やした時間が当該最大値を超えると予想される場合には、たとえエラー受信が解消されていなくても、当該アイソクロナスデータの再送を中止させることを特徴とする、請求項15に記載の通信制御方法。
- 17【請求項17】 前記最大値が、非アイソクロナス領域の時間長を超えない値であることを特徴とする、請求項16に記載の通信制御方法。
- 18【請求項18】 前記最大値が、非アイソクロナス領域の時間長と等しい値であることを特徴とする、請求項17に記載の通信制御方法。
- 19【請求項19】 再送中止されたアイソクロナスデータを、次のサイクル内の非アイソクロナス領域で再送させることを特徴とする、請求項17に記載の通信制御方法。
- 20【請求項20】 同一のアイソクロナスデータを再送する回数の最大値が決められており、再送回数が当該最大値に達した場合には、たとえエラー受信が解消されていなくても、当該アイソクロナスデータの再送を中止させることを特徴とする、請求項15に記載の通信制御方法。
- 21【請求項21】 複数の端末を互いに接続してなるネットワーク上において、等時性が要求されるアイソクロナスデータと、そうでない非アイソクロナスデータとを混在させてシリアル伝送するべく各端末の通信を制御する装置であって、 時間をサイクルに区切って、1つ1つのサイクル内に、アイソクロナス領域と、非アイソクロナス領域とを設ける手段、 1つ1つのサイクル内で各端末が前記アイソクロナス領域を時分割的に利用してアイソクロナスデータを送信した後、送信先の端末によって当該アイソクロナスデータがエラーなく受信されたか否かを判定する手段、およびアイソクロナスデータをエラー受信した端末が存在する場合、当該アイソクロナスデータの送信元である端末に命じて、前記非アイソクロナス領域を利用して当該アイソクロナスデータを再送させる手段を備える、通信制御装置。
- 22【請求項22】 複数の端末を互いに接続してなるネットワーク上において、等時性が要求されるアイソクロナスデータと、そうでない非アイソクロナスデータとを混在させてシリアル伝送するべく各端末の通信を制御する方法を、コンピュータ処理可能に記述したプログラムであって、 時間をサイクルに区切って、1つ1つのサイクル内に、アイソクロナス領域と、非アイソクロナス領域とを設け、 1つ1つのサイクル内で各端末が前記アイソクロナス領域を時分割的に利用してアイソクロナスデータを送信した後、送信先の端末によって当該アイソクロナスデータがエラーなく受信されたか否かを判定し、 アイソクロナスデータをエラー受信した端末が存在する場合、当該アイソクロナスデータの送信元である端末に命じて、前記非アイソクロナス領域を利用して当該アイソクロナスデータを再送させることを特徴とする方法を、コンピュータ処理可能に記述した、通信制御プログラム。
- 23【請求項23】 複数の端末を互いに接続してなるネットワーク上において、等時性が要求されるアイソクロナスデータと、そうでない非アイソクロナスデータとを混在させてシリアル伝送するべく各端末の通信を制御する方法を、コンピュータ処理可能に記述したプログラムが格納された記録媒体であって、 時間をサイクルに区切って、1つ1つのサイクル内に、アイソクロナス領域と、非アイソクロナス領域とを設け、 1つ1つのサイクル内で各端末が前記アイソクロナス領域を時分割的に利用してアイソクロナスデータを送信した後、送信先の端末によって当該アイソクロナスデータがエラーなく受信されたか否かを判定し、 アイソクロナスデータをエラー受信した端末が存在する場合、当該アイソクロナスデータの送信元である端末に命じて、前記非アイソクロナス領域を利用して当該アイソクロナスデータを再送させることを特徴とする方法を、コンピュータ処理可能に記述した通信制御プログラムが記録された、記録媒体。
Independent claims23
330 paragraphs in 1 section, as filed
Description: TECHNICAL FIELD [Detailed description of the invention]
【0001】
[Technical field to which the invention belongs]
The present invention relates to a communication control method, and more specifically, serially mixes isochronous data that requires isochronism and non-isochronous data that does not require isochronism on a network formed by connecting a plurality of terminals to each other. The present invention relates to a method of controlling communication of each terminal for transmission.
【0002】
[Conventional technology]
In recent years, in homes and offices, computers, peripheral devices, digital video devices, and the like have come to be connected to each other to form a narrow network. In this type of network, isochronous data that requires isochronism (for example, video / audio data for streaming playback) and non-ichronous data that does not (for example, communication data transmitted in bursts) are mutually present. It is serially transmitted over the network in a mixed state.
【0003】
For example, IEEE1394 is known as a standard for serially transmitting isochronous data and non-isochronous data in a mixed manner. In IEEE1394, the following communication control is performed for each device constituting the network.
【0004】
FIG. 23 is a diagram showing a configuration example of a conventional narrow-area network 209 compliant with IEEE1394, and FIG. 24 is a schematic diagram for explaining a conventional communication control method by IEEE1394. FIG. 24 (A) shows a configuration example of a communication control cycle by IEEE1394, and FIG. 24 (B) shows an example of communication control performed in the network 209 of FIG. 23.
【0005】
In FIG. 23, the conventional network 209 includes a controller 210, a digital video 211, a digital television 212, a set-top box (STB) 213, and a computer 214, and these devices 210 to 214 are cables. It is connected serially (or in a tree shape) via (IEEE1394 compliant cable). In this network 209, the controller 210 controls the communication between the other devices 211 to 214.
【0006】
In the network 209 configured as described above, the isochronous data "I1" from the digital video 211 to the digital television 212, the isochronous data "I2" from the STB213 to the computer 214, and the non-isochronous data from the computer 214 to the digital video 211 are now present. Suppose that "N" is being sent respectively.
【0007】
In IEEE1394, as shown in FIG. 24 (A), the control time is divided into fixed cycles (for example, 125 μsec), and an isochronous region having a predetermined time length (for example, 100 μsec at the maximum) is provided in each cycle. Then, the isochronous area is divided into multiple parts (in this case, divided into two parts), and each of them is used as a dedicated area (Ch.1 and Ch.2) to the device (digital television 211 and STB213) having the isochronous data to be transmitted. Assigned.
【0008】
After that, as shown in FIG. 24 (B), the controller 210 transmits the information 200 (which describes the time when the transmission of isochronous data should be executed) about the dedicated area allocated to each device, prior to the start of transmission. Notify each device. When transmission is started and the current time enters the first cycle, the controller 210 sends a packet 201 indicating the start of the cycle to each device. Upon receiving cycle start packet 201, devices with isochronous data to transmit (digital video 211 and STB213) transmit isochronous data (I1 and I2) using their own dedicated area (Ch.1 and Ch.2). To do.
【0009】
Then, when the current time leaves the isochronous region, the controller 210 gives a transmission instruction 202 to the device (computer 214) having the non-isochronous data to be transmitted. The computer 214 receives the instruction 202 from the controller 210 and transmits its non-isochronous data (N).
【0010】
Next, the device (digital video 211) to which the non-isochronous data (N) is transmitted receives the non-isochronous data and indicates the success or failure of the reception to the source terminal (computer 214) and the controller 210. Return response packet 203. The controller 210 receives the response packet 203 from the computer 214 and determines whether or not it is necessary to perform retransmission. In this case, since the sent response packet 203 indicates successful reception, the controller 210 determines that it is not necessary to retransmit. Then, when the controller 210 exits one cycle and enters the next cycle, the controller 210 transmits a packet indicating the start of the next cycle to each terminal (not shown), and thereafter, the same operation is repeated.
【0011】
When the response packet 203 returned from the digital video 211 indicates an error reception, the controller 210 transmits a retransmission instruction to the computer 214, which is the source of the non-isochronous data (N) (not shown; below). Similarly). Accordingly, the computer 214 retransmits the non-isochronous data (N). The destination digital video 211 then returns a response packet to computer 214 and controller 210. The controller 210 orders the computer 214 to resend again if the response packet from the digital video 211 indicates a reception failure.
【0012】
In this way, in IEEE1394, the time is divided into cycles, and an isochronous region having a fixed time length is secured in each cycle. Then, since this isochronous area is divided into many parts and each of them is assigned to each device as a dedicated area, each device can transmit isochronous data once per cycle, and as a result, the isochronous data. Isotropic is maintained.
【0013】
On the other hand, in a region other than isochronous (hereinafter, non-isochronous region) in each cycle, control (asynchronous control) is performed so that devices having non-isochronous data to be transmitted execute transmission in order. This makes it possible to mix isochronous data and non-ichronous data for serial transmission.
【0014】
[Problems to be Solved by the Invention]
By the way, in IEEE1394, retransmission control is not performed even if isochronous data is received in error. Instead, by limiting the length of the cable connecting each device to a predetermined length (4.5 m for a conductor cable) or less, the occurrence rate of transmission errors is suppressed to a certain value or less. This is because if the occurrence rate of the transmission error is less than a certain value, the deterioration of the quality of the image and the sound quality is suppressed to the extent that the user cannot recognize it.
【0015】
However, recently, there is a growing demand for wireless connection between devices. This is because if the connection is made wireless, troublesome wiring work is not required, and each device can be moved to a desired place for use.
【0016】
However, a wireless transmission line is more likely to cause a transmission error than a wired transmission line. In particular, if the devices are far apart from each other or if there are obstacles between the devices, the incidence of transmission errors will increase significantly, resulting in distorted images during streaming playback and noise in the audio. There is a high possibility.
【0017】
Therefore, an object of the present invention is that when isochronous data and non-ichronous data are mixed and serially transmitted, the image during streaming playback is distorted even if communication is performed through a transmission line having a high transmission error occurrence rate. It is to provide a communication control method so that noise is not mixed in the voice.
【0018】
[Means for Solving Problems and Effects of Invention]
The first invention controls the communication of each terminal so that isochronous data that requires isochronism and non-isochronous data that does not require isochronous data are mixed and serially transmitted on a network in which a plurality of terminals are connected to each other. In this method, the time is divided into cycles, an isochronous region and a non-isochronous region are provided in each cycle, and each terminal uses the isochronous region in a time-divided manner in each cycle. After transmitting the isochronous data, it is determined by the destination terminal whether or not the isochronous data has been received without error, and if there is a terminal that has received the isochronous data with an error, the terminal that is the source of the isochronous data. It is characterized in that the isochronous data is retransmitted by using the non-isochronous region.
【0019】
In the first aspect of the invention, when the isochronous data is received in error, the non-isochronous region is used to retransmit the data, so that the transmission error of the isochronous data can be reduced without impairing the isochronism. As a result, even if the transmission line between the terminals is a transmission line such as a wireless transmission line where the occurrence rate of transmission errors is high, the video during streaming playback is not disturbed or the audio is not interrupted.
【0020】
The second invention is the case where, in the first invention, each terminal adds an error detection code to the isochronous data and transmits the isochronous data, and the destination terminal receives the isochronous data and inspects the error detection code. It is characterized in that a judgment is made based on the result of the inspection. In the second invention, since the inspection result of the error detection code attached to the isochronous data is sent from the terminal to which the isochronous data is transmitted, it is determined whether or not the isochronous data is received without error. Can be done.
【0021】
A third invention is characterized in that, in the first invention, when each terminal divides isochronous data into blocks and transmits the isochronous data, a determination is made in block units and retransmission is performed in block units.
【0022】
In the third invention described above, since the icronous data is divided into a plurality of blocks and transmitted, if an error occurs in only a part of the data, only the block in which the error has occurred needs to be retransmitted, and as a result. , The time spent on resending is reduced. This makes it possible to further reduce the possibility of running out of time to transmit the non-isochronous data, which is expected to occur when the isochronous data is retransmitted using the non-isochronous region.
【0023】
When there are a plurality of terminals that have received the isochronous data in error, the control as in the fourth or fifth invention below is performed.
【0024】
In the fourth invention, in the first invention, when there are a plurality of terminals that have received an error in isochronous data, each terminal time-divides the non-isochronous region with respect to each terminal that is the source of the isochronous data. It is characterized in that the retransmission is sequentially instructed so that the isochronous data is resent by utilizing the data.
【0025】
In the fifth invention, in the first invention, when there are a plurality of terminals that have received an error in isochronous data, each terminal time-divides the non-isochronous region with respect to each terminal that is the source of the isochronous data. It is characterized in that each transmission time is collectively notified so that the isochronous data is retransmitted by using the data.
【0026】
According to the fourth or fifth invention, a plurality of terminals can retransmit isochronous data by using the non-isochronous region in a time-division manner.
【0027】
The sixth invention is characterized in that, in the first invention, when each terminal modulates and transmits isochronous data, the modulation method is changed and then retransmission is performed.
【0028】
The seventh invention is characterized in that, in the first invention, when each terminal encodes and transmits isochronous data, the encoding rate is changed and then the data is retransmitted.
【0029】
Eighth invention is characterized in that, in the first invention, when each terminal encodes and modulates isochronous data and transmits the isochronous data, the modulation method and the coding rate are changed and then retransmission is performed.
【0030】
According to the sixth to eighth inventions described above, the probability that a transmission error will occur again at the time of retransmission can be reduced. As a result, the number of retransmissions is suppressed, and the possibility of running out of time to transmit non-isochronous data can be further suppressed.
【0031】
According to the ninth invention, in the first invention, when each terminal multicasts isochronous data to a plurality of terminals belonging to a specific group as a transmission destination, the isochronous data is errored by all the terminals belonging to the destination group. If there is at least one terminal in the group that has received the isochronous data in error, it is characterized by multicasting the isochronous data to all the terminals in the group as destinations. And.
【0032】
According to the ninth invention, even in a network in which each terminal performs multicast transmission, it is possible to reduce isochronous data transmission errors without impairing its isochronism.
【0033】
According to the tenth invention, in the first invention, when each terminal broadcasts isochronous data to all other terminals as transmission destinations, whether or not the isochronous data is received by all the destination terminals without error. If there is at least one terminal that has received the isochronous data in error, the isochronous data is broadcast-retransmitted to all the terminals as transmission destinations.
【0034】
According to the tenth invention, even in a network in which each terminal performs broadcast transmission, transmission errors of isochronous data can be reduced without impairing its isochronism.
【0035】
In the eleventh invention, in the first invention, the isochronous region is divided into multiple parts so that each terminal uses the isochronous region in a time-division manner to transmit isochronous data in each cycle. Each terminal is assigned as a dedicated area, and information about the dedicated area is notified to each terminal before the start of the first cycle.
【0036】
In the eleventh invention described above, the dedicated area information is notified to each terminal before the start of the first cycle. Each terminal refers to the dedicated area information and transmits isochronous data at a time corresponding to the dedicated area assigned to it in each cycle.
【0037】
In the twelfth invention, in the first invention, the isochronous region is divided into multiple parts so that each terminal uses the isochronous region in a time-division manner to transmit isochronous data in each cycle. Each terminal is assigned as a dedicated area, and each terminal is sequentially instructed to transmit at a time corresponding to the dedicated area in each cycle.
【0038】
In the twelfth invention described above, transmission is sequentially instructed to each terminal at a time corresponding to the dedicated area in each cycle. Each terminal transmits isochronous data in response to an instruction.
【0039】
A thirteenth invention is characterized in that, in the first invention, an inquiry is made to a transmission destination terminal whether or not isochronous data is received without an error, and a determination is made upon receiving the response.
【0040】
In the thirteenth invention described above, the destination terminal is inquired about the presence or absence of an error.
【0041】
A fourteenth invention is characterized in that, in the first invention, a determination is made after receiving a response from a transmission destination terminal whether or not isochronous data has been received without error.
【0042】
In the fourteenth invention described above, the presence or absence of an error is spontaneously responded from the transmission destination terminal.
【0043】
The fifteenth invention is characterized in that, in the first invention, when the retransmitted isochronous data is received again with an error, the isochronous data is repeatedly retransmitted until the error reception is resolved.
【0044】
In the fifteenth invention described above, retransmission is repeated until the reception error is resolved.
【0045】
In the fifteenth invention, in the fifteenth invention, the maximum value of the time that can be spent for retransmitting isochronous data in each cycle is determined, and when another retransmission is executed, the time spent for retransmission is determined. When it is expected that the maximum value will be exceeded, the retransmission of the isochronous data is stopped even if the error reception is not resolved.
【0046】
In the sixteenth invention described above, by limiting the retransmission time of isochronous data to a certain value or less, it is possible to prevent the isochronous data from being impaired and the transmission time of non-isochronous data from being insufficient.
【0047】
The seventeenth invention is characterized in that, in the sixteenth invention, the maximum value is a value that does not exceed the time length of the non-isochronous region.
【0048】
According to the seventeenth invention described above, it is possible to prevent the retransmission of isochronous data even if it enters the isochronous region of the next cycle. If the isochronous data is retransmitted within the isochronous region, the isochronous data may be impaired, but this is avoided.
【0049】
The eighteenth invention is characterized in that, in the seventeenth invention, the maximum value is equal to the time length of the non-isochronous region.
【0050】
In the above eighteenth invention, since the entire non-isochronous region can be used for retransmission of isochronous data, transmission error of isochronous data can be most effectively reduced.
【0051】
A nineteenth invention is characterized in that, in the seventeenth invention, the isochronous data whose retransmission has been aborted is retransmitted in a non-isochronous region within the next cycle.
【0052】
In the nineteenth invention, the isochronous data whose retransmission has been canceled is retransmitted after entering the non-isochronous region in the next cycle.
【0053】
In the twentieth invention, in the fifteenth invention, the maximum value of the number of times to retransmit the same isochronous data is determined, and when the number of retransmissions reaches the maximum value, even if the error reception is not resolved. However, it is characterized in that the retransmission of the isochronous data is stopped.
【0054】
In the twentieth invention, it is possible to prevent the same isochronous data from being retransmitted endlessly.
【0055】
The twenty-first invention controls the communication of each terminal so that isochronous data that requires isochronism and non-isochronous data that does not require isochronous data are mixed and serially transmitted on a network in which a plurality of terminals are connected to each other. A means to divide the time into cycles and provide an isochronous region and a non-isochronous region in each cycle, and each terminal time-divides the isochronous region in each cycle. After transmitting isochronous data by using it, there is a means to determine whether or not the isochronous data was received without error by the destination terminal, and if there is a terminal that received the isochronous data with error, the source of the isochronous data. A means for instructing a terminal to retransmit the isochronous data using the non-isochronous region is provided.
【0056】
The 22nd invention is a program that describes a method like the 1st invention in a computer-processable manner.
【0057】
The 23rd invention is a recording medium in which a program such as the 22nd invention is stored.
【0058】
BEST MODE FOR CARRYING OUT THE INVENTION
(First Embodiment) FIG. 1 is a schematic diagram for explaining a communication control method according to the first embodiment of the present invention, and FIG. 2 is a wireless narrow area network 9 to which the method of FIG. 1 is applied. It is a figure which shows the configuration example. In FIG. 2, the wireless narrow-area network 9 includes a controller 10, a digital video 11, a digital television 12, a set-top box (hereinafter referred to as STB) 13, and a computer 14, and these devices 10 to 14 are provided. They are connected to each other wirelessly. This network 9 is considered to be equivalent to network 209 (see the prior art section) in FIG. 23, except that the occurrence rate of transmission errors is high because each device 10 to 14 is wirelessly connected. You can. In this network 9, the controller 10 controls wireless communication between other devices (11 to 14).
【0059】
Each device (10 to 14) constituting the wireless narrow area network 9 is provided with a wireless communication module. Figure 3 shows an example of the configuration of the wireless communication module. In FIG. 3, the wireless communication module 20 includes an antenna 21, a modulation / demodulation circuit 22, a processing circuit 23, a program memory 24, and an input / output circuit 25.
【0060】
The antenna 21 converts a signal into a radio wave and radiates it, and also captures the radio wave and converts it into a signal. The modulation / demodulation circuit 22 modifies and demolishes the signal. The input / output circuit 25 is connected to an input / output circuit (not shown) of a device (10 to 14) on which the module is mounted, and exchanges a signal with the device.
【0061】
Various programs are stored in the program memory 24. The processing circuit 23 includes a microcomputer and processes a signal according to a program in the program memory 24. The contents of the program memory 24 are shown in FIG.
【0062】
In FIG. 4, the program memory 24 stores the basic program 30, the control station program 31, and the terminal program 32. The basic program 30 describes the basic processing procedure for the module to perform wireless communication, the control station program 31 describes the procedure for the module to control the communication of each terminal as a control station, and the terminal program 32 describes the procedure. The procedure for the module to communicate as a terminal is described in a computer-processable manner.
【0063】
The control program is activated in the wireless communication module 20 mounted on the controller 10, and the terminal program 32 is activated in the wireless communication module 20 mounted in each of the other devices 11 to 14. By changing this initial setting, for example, the computer 14 or STB13 can be operated as a control station.
【0064】
In the network 9 configured as described above, isochronous data (I1) is now transferred from digital video 11 (first terminal) to digital television 12 (second terminal) from STB13 (third terminal) to computer 14 (fourth terminal). It is assumed that isochronous data (I2) is being sent to the terminal) and non-isochronous data (N) is being sent from the computer 14 (fourth terminal) to the digital video 11 (first terminal). At this time, the controller 10 (control station) performs each device (1st to 4th) in order to serially transmit isochronous data that requires isochronism and non-isochronous data that does not require isochronism on the network 9. Control the communication of the terminal).
【0065】
In the following, the controller 10 will be referred to as a "control station", and the devices 11 to 14 will be referred to as "first to fourth terminals". In this communication control, as shown in FIG. 1 (A), the time is divided into fixed cycles, and an isochronous region and a non-isochronous region are provided in each cycle. Then, the isochronous area is divided into multiple parts (in this case, divided into two), and each terminal has the isochronous data to be transmitted (1st and 3rd terminals) as a dedicated area (Ch.1 and Ch.2). ).
【0066】
Here, the time length of the isochronous region is determined according to the amount of isochronous data transmitted in a unit time. However, the transmission line is limited to a predetermined value or less so as not to be occupied by isochronous data. For example, if one cycle is 125 μsec, the time length of the isochronous region is limited to, for example, 100 μsec or less.
【0067】
Further, the isochronous region is provided at a position separated from the beginning of the cycle by a predetermined time. Therefore, in one cycle, the two regions before and after the isochronous region are non-isochronous regions. In addition, the control station recognizes the amount of isochronous data transmitted by each terminal per unit time, divides the isochronous area into multiple parts according to the transmission amount of each terminal, and each of them is used as a dedicated area. Assign to a terminal.
【0068】
FIG. 1 (A) shows a configuration example of a communication control cycle, and FIG. 1 (B) shows an example of communication control performed in the network 9 of FIG. In the example of FIG. 1 (A), an isochronous region is provided at a position of 5 to 85 μsec with the origin (0 μsec) at the beginning of the cycle in one cycle. Therefore, two regions, 0 to 5 μsec and 80 to 125 μsec, are non-isochronous regions. Then, the isochronous region is divided into two dedicated regions (Ch.1 and Ch.2) of 5 to 25 μsec and 25 to 85 μsec, and the former (Ch.1) becomes the first terminal and the latter (Ch.2). ) Is assigned to each of the third terminals.
【0069】
After allocating the dedicated area in this way, the control station notifies each terminal of the information 40 regarding the dedicated area allocated to each terminal prior to the start of transmission, as shown in FIG. 1 (B). When transmission is started and the current time enters the first cycle, the control station transmits a packet 41 indicating the start of the cycle to each terminal. The cycle start packet 41 is transmitted in the non-isochronous region of 0 to 5 μsec.
【0070】
Correspondingly, terminals (first and third terminals) that have isochronous data (I1 and I2) to be transmitted use their own dedicated areas (Ch.1 and Ch.2) to generate isochronous data (I1 and I2). Send. At this time, the third terminal divides the isochronous data I2 into three blocks (I2-1, I2-2 and I2-3) and transmits the isochronous data I2 (the reason will be described later).
【0071】
When the current time leaves the isochronous region, the control station first queries whether the previously transmitted isochronous data (I1 and I2) have been received without error. Specifically, each terminal (second and fourth terminal) to which I1 and I2 are transmitted is inquired in order about the success or failure of reception. That is, first, the inquiry packet 42 is transmitted to the second terminal, and the response packet 43 is returned from the second terminal. Then, when the response packet 43 is returned from the second terminal, the inquiry packet 44 is transmitted to the fourth terminal, and the response packet 45 is returned from the fourth terminal. Then, when the response packet 45 is returned from the fourth terminal, it is necessary to analyze the contents of the two response packets 43 and 45 from the second and fourth terminals and retransmit the isochronous data I1 and I2. To judge. In this case, since all the sent response packets indicate successful reception, the control station determines that there is no need for retransmission and shifts to communication control of non-isochronous data.
【0072】
That is, the control station gives a transmission instruction 46 to the terminal (fourth terminal) having the non-isochronous data to be transmitted. The fourth terminal receives the instruction 46 from the control station and transmits the non-isochronous data (N). The terminal (first terminal) to which the non-isochronous data is transmitted returns a response packet 47 indicating the success or failure of reception to the source terminal (fourth terminal) and the control station. In this case, since the sent response packet 47 indicates successful reception, the control station determines that it is not necessary to retransmit, and if there is another terminal having non-isochronous data to be transmitted, the terminal is permitted to transmit. If not, wait as it is.
【0073】
Then, when the first cycle is exited and the next cycle is entered, the control station transmits a packet indicating the start of the next cycle to each terminal, and thereafter, the same operation is repeated. The above is an example of communication control performed in the network 9 of FIG.
【0074】
By the way, in the example of FIG. 1 (B), all the transmitted isochronous data (blocks) are received without an error, but the processing when an error reception occurs is as shown in FIG.
【0075】
FIG. 5 is a schematic diagram for explaining the retransmission control performed when the isochronous data (block) is received in error. FIG. 5 shows retransmission control when the isochronous block I2-3 transmitted from the third terminal receives an error by the fourth terminal. In this case, the fourth terminal receives the inquiry packet 50 from the control station and returns the response packet 51 indicating that the isochronous block I2-3 has received an error. Since the response packet 51 returned from the 4th terminal indicates the error reception of the isochronous block I2-3, the control station determines that the retransmission is necessary, and issues the retransmission instruction 52 of the isochronous block I2-3 to the 3rd terminal. Send to. Accordingly, the third terminal resends the isochronous block I2-3 to the fourth terminal.
【0076】
Next, the control station sends a packet 53 for inquiring about the success or failure of reception to the fourth terminal which is the retransmission destination of the isochronous block I2-3. Since the fourth terminal has received the retransmitted isochronous block I2-3 without error, it returns a response packet 54 to that effect. Since the response packet 54 returned from the fourth terminal indicates successful reception, the control station determines that further retransmission is not necessary, and shifts to communication control of non-isochronous data.
【0077】
As described above, according to this communication control method, when the isochronous data is received in error, the data is retransmitted using the non-isochronous region, so that the transmission error of the isochronous data is reduced without impairing the isochronism. be able to.
【0078】
Also, since the terminal divides the icronus data into a plurality of blocks and transmits it, if an error occurs in only a part of the data, it is sufficient to resend only the block in which the error occurred, and the time spent for retransmission It will be shortened. This makes it possible to further reduce the possibility of running out of time to transmit the non-isochronous data, which is expected to occur when the isochronous data is retransmitted using the non-isochronous region.
【0079】
In the example of FIG. 5, the isochronous data I2 is transmitted by dividing it into three blocks (I2-1, I2-2 and I2-3), but in general, the larger the number of divisions, the more the non-isochronous data is transmitted. You can reduce the possibility of running out of time. However, when isochronous data is divided into a plurality of blocks and transmitted, error detection must be performed for each block. Therefore, the larger the number of divisions, the larger the amount of processing for error detection. Therefore, it is preferable to select an appropriate number of divisions in consideration of the balance between the two.
【0080】
The retransmission process when the non-isochronous data is received in error is the same as the conventional one. For example, when the response packet returned from the first terminal indicates a reception failure, the control station transmits a retransmission instruction to the fourth terminal, which is the source of the non-isochronous data (N). Accordingly, the fourth terminal retransmits the non-isochronous data. Next, the first terminal, which is the retransmission destination, returns a response packet to the fourth terminal and the control station. If the response packet indicates a reception failure, the control station orders the fourth terminal to resend again.
【0081】
As described above, in this communication control method, time is divided into cycles, and an isochronous region and a non-isochronous region are provided in each cycle. Then, the communication control of the isochronous data is performed in the isochronous region, and in the non-isochronous region, the retransmission control of the isochronous data received in error is performed first, and then the communication control of the non-isochronous data is executed.
【0082】
As a result, isochronous data and non-ichronous data can be mixed and serially transmitted, and transmission errors of isochronous data can be reduced without impairing the isochronism. As a result, even if the transmission line between the terminals is a transmission line such as a wireless transmission line where the occurrence rate of transmission errors is high, the video during streaming playback is not disturbed or the audio is not interrupted.
【0083】
In the example of FIG. 5, the retransmitted isochronous data (block I2-3) is received without an error, but an error may be received again. In such a case, retransmission is repeated until the reception error is resolved. However, if the maximum value of the time that can be spent retransmitting isochronous data in one cycle is predetermined and it is expected that the total retransmission time will exceed the maximum value if another retransmission is performed. Even if the reception error is not resolved, the retransmission is stopped at that point. The situation is shown in Fig. 6.
【0084】
In general, the maximum value of the retransmission time of isochronous data per cycle is determined so as not to exceed the time length of the non-isochronous region. Otherwise, the isochronous data will not be isochronous. In FIG. 6, the above maximum value is set to a value equal to the time length of the non-isochronous region (for example, 45 μsec). This is the setting when the highest priority is given to eliminating the transmission error of isochronous data. However, if it is set as shown in FIG. 6, non-isochronous data may not be transmitted at all, so it is usually set to a value smaller than the time length of the non-isochronous region (for example, 30 μsec).
【0085】
Next, the operation of the control station will be described with reference to a flowchart. FIG. 7 is a flowchart showing the operation of the control station (10) of FIG. In FIG. 7, the control station first divides the time into cycles and sets an isochronous region and a non-isochronous region in each cycle (step S1). It then sets the maximum amount of time that can be spent retransmitting isochronous data in one cycle (step S2). This maximum value is set to a value that does not exceed the time length of the non-isochronous region. Further, the maximum number of retransmissions indicating how many times the same isochronous data can be retransmitted is set (step S3). The maximum number of retransmissions will be described later.
【0086】
Next, the control station divides the isochronous area set in step S1 into multiple parts and allocates each of them as a dedicated area to each terminal (step S4). Then, the information regarding the allocated dedicated area is notified to each terminal in advance before the start of transmission (step S5). In this dedicated area information, the timing at which each terminal transmits isochronous data is described. Figure 8 shows an example of dedicated area information. As shown in FIG. 8, the dedicated region information packets, each isochronous data transmission time of data it is described for each block.
【0087】
After that, the control station notifies each terminal of the start of the cycle (step S6). Correspondingly, each terminal transmits isochronous data using the dedicated area assigned to it. Next, the control station determines whether or not the isochronous data transmitted from each terminal has been received by the transmission destination terminal without error (step S7). If the determination result is affirmative, the process proceeds to step S11.
【0088】
If the determination result in step S7 is negative, the control station determines whether the total time spent on retransmission exceeds the maximum value set in step S2 when another retransmission is executed within the one cycle. (Step S8). If the determination result is affirmative, the retransmission is stopped and the process proceeds to step S11.
【0089】
If the determination result in step S8 is negative, the control station determines whether or not the number of retransmissions of the isochronous data received in error has reached the maximum number of retransmissions set in step S3 (step S9). If the determination result is affirmative, the process returns to step S7 and the same process as described above is repeated.
【0090】
If the determination result in step S9 is negative, the source terminal is instructed to resend the isochronous data received in error (step S10). In response, the source terminal retransmits the isochronous data using the non-isochronous region. After that, the control station returns to step S7 and repeats the same process as described above. In step S11, the control station controls transmission of the non-isochronous data until the current time reaches the end of the non-isochronous region.
【0091】
In the following step S12, it is determined whether or not the cycle is the last cycle, and if the determination result is affirmative, the operation of the control station is terminated. If the determination result in step S12 is negative, the control station returns to step S6, notifies each terminal of the start of the next cycle, and then repeats the same operation as described above.
【0092】
The above is the operation of the control station. Next, the operation of the terminal will be described. FIG. 9 is a flowchart showing the operation of each terminal (11 to 14) of FIG. In FIG. 9, the terminal first determines if there is isochronous data to be transmitted (step S21). If the determination result is negative, the process proceeds to step S23.
【0093】
If the determination result in step S21 is affirmative, the terminal executes the isochronous data transmission process (step S22). Next, it is determined whether or not there is non-isochronous data to be transmitted (step S23), and if the determination result is negative, the process proceeds to step S25.
【0094】
If the determination result in step S23 is affirmative, the terminal transmits non-isochronous data (step S24), and then proceeds to step S25. An error detection code is added to the non-isochronous data transmitted at this time. In step S25, the terminal determines whether or not there is data to be received. If the determination result in step S25 is affirmative, the terminal executes data reception processing (step S26), and then proceeds to step S27. If the determination result in step 25 is negative, step S26 is skipped and the process proceeds to step S27.
【0095】
In step S27, it is determined whether or not to continue the operation. If the determination result is affirmative, the terminal ends the operation, and if the determination result is negative, the terminal returns to step S21 and repeats the same process as described above.
【0096】
FIG. 10 is a flowchart showing details of the isochronous data transmission process shown in step S22 of FIG. In FIG. 10, the terminal first receives the notification of the dedicated area information from the control station (step S41). Then, it waits for the start of the cycle to be notified (step S42).
【0097】
When notified of the start of the cycle, the terminal transmits isochronous data using the allocated dedicated area (step S43). That is, the isochronous data is transmitted at the time described in the dedicated area information received in step S41. An error detection code is added to the isochronous data transmitted at this time.
【0098】
Next, the terminal determines whether or not a retransmission instruction has been received from the control station (step S44). If the determination result is negative, the terminal returns to the flow of FIG. 9 and executes step S23. If the determination result in step S44 is affirmative, the terminal retransmits the isochronous data using the non-isochronous region (step S45). An error detection code is added to the isochronous data retransmitted at this time. After that, the terminal returns to the flow of FIG. 9 and executes step S23. The above is the details of step S22.
【0099】
FIG. 11 is a flowchart showing the details of the data reception process shown in step S26 of FIG. In FIG. 11, the terminal first receives the data sent to itself (step S61), and then checks whether the received data is error-free (step S62). Since an error detection code is added to the sent data, it is possible to check the presence or absence of an error based on this code.
【0100】
Next, the terminal transmits a response packet including the check result of step S62 to the control station (step S63), and then returns to the flow of FIG. 9 to execute step S27. A configuration example of the response packet is shown in FIG. As shown in FIG. 12, in the response packet, the reception status (presence or absence of error) of isochronous data is described for each block. The above is the details of step S26.
【0101】
The isochronous data whose retransmission is canceled because the retransmission time is determined to exceed the maximum value in step S8 is retransmitted in the non-isochronous region in the next cycle. The situation is shown in FIG. In FIG. 13, the retransmission of the isochronous data I1 is temporarily stopped at the rear end of the cycle 61, and the retransmission is restarted after entering the non-isochronous region in the next cycle 62.
【0102】
However, if the same isochronous data is retransmitted many times, there is no time to retransmit other isochronous data. In order to prevent this, the retransmission of the same data is limited to a predetermined number of times (for example, twice) or less. This is the maximum number of retransmissions set in step S3. In the example of FIG. 13, the transmission error is not resolved even if the second retransmission is performed in the non-isochronous region in the next cycle 62, but the number of retransmissions of the same data is limited to 2 or less, so 3 The second retransmission is not performed.
【0103】
Here, in order to reduce the number of retransmissions, the control station determines the modulation method and / or the coding rate when issuing a retransmission instruction to the terminal of the source of the isochronous data received in error (see step S10 above). You may order to change.
【0104】
That is, when transmitting isochronous data, each terminal encodes the data at a predetermined rate, further modulates the data by a predetermined method, and then transmits the data. If the modulation method is changed to another method at the time of retransmission, the probability of occurrence of a transmission error can be reduced as compared with using the same modulation method. Further, if the coding rate is changed to another coding rate at the time of retransmission, the probability of occurrence of a transmission error can be reduced as compared with using the same coding rate. Further, at the time of retransmission, if the modulation method is changed to another method and the coding is also changed to another coding rate, the probability of occurrence of a transmission error can be further reduced. As a result, the number of retransmissions is suppressed, and the possibility of running out of time to transmit non-isochronous data can be further suppressed.
【0105】
By the way, in the first embodiment, each terminal transmits isochronous data to one terminal, but it is also possible to multicast the isochronous data to a plurality of terminals belonging to a specific group as transmission destinations. .. Alternatively, each terminal can broadcast isochronous data to all other terminals as transmission destinations. In the second embodiment, communication control when each terminal multicasts or broadcasts isochronous data will be described.
【0106】
(Second Embodiment) FIG. 14 is a schematic diagram for explaining a communication control method according to a second embodiment of the present invention. An example of a wireless narrow network configuration to which the method of FIG. 14 is applied is shown in FIG. The configuration of the wireless communication module 20 mounted on the control station and each terminal in FIG. 2 is shown in FIG. The contents of the program memory 24 of FIG. 3 are shown in FIG. However, the control station program 31 and the terminal program 32 are partially different from the first embodiment.
【0107】
In the example of FIG. 14, in the isochronous region, the first terminal broadcasts three isochronous blocks (I1-1, I1-2 and I1-3) to the second to fourth terminals. When there are many terminals other than those shown in the figure and the second to fourth terminals belong to one group, FIG. 14 shows multicast transmission to the terminals belonging to the group. Can be regarded as.
【0108】
The second terminal receives the block I1-1 with an error, and receives the blocks I1-2 and I1-3 without an error. The fourth terminal receives blocks I1-1 and I1-2 without any error, and blocks I1-3 with an error. The third terminal is receiving blocks I1-1, I1-2 and I1-3 without any error.
【0109】
In the non-isochronous region, the control station sequentially transmits packets 70 to 72 inquiring the success or failure of reception to the second to fourth terminals which are the transmission destinations. Then, in response to the sequential response packets 73 to 75 being sent from the second to fourth terminals, the isochronous block (I1-1 and I1-3) that received an error to the first terminal that is the source. Packets 76 and 77 instructing the retransmission of are sequentially transmitted.
【0110】
Accordingly, the first terminal broadcasts and retransmits blocks I1-1 and I1-3, and the second to fourth terminals receive them. Next, the control station sequentially transmits packets 78 and 79 inquiring about the reception status to the second and fourth terminals that have received the blocks I1-1 and I1-3 in error. Then, in response to the response packets 80 and 81 indicating that the second and fourth terminals have received without error, the retransmission process is terminated.
【0111】
The operation of the control station is shown in the flowchart of FIG. However, when each terminal multicasts isochronous data to a plurality of terminals belonging to a specific group as transmission destinations, in step S7 above, the control station receives the isochronous data by all the terminals belonging to the group without error. Determine if it is. Then, if there is at least one terminal in the group that has received the isochronous data in error, the isochronous data is multicast-retransmitted to all the terminals in the group as transmission destinations.
【0112】
On the other hand, when each terminal broadcasts isochronous data to all other terminals as transmission destinations, in step S7, the control station determines whether or not the isochronous data has been received by all the destination terminals without error. To judge. Then, if there is even one terminal that has received the isochronous data in error, the isochronous data is broadcast-retransmitted to all terminals as transmission destinations.
【0113】
By the way, in the first embodiment, the control station sequentially makes inquiries about the success or failure of reception to each terminal to which the isochronous data is transmitted, but it is also possible to make inquiries to each terminal collectively. it can. Further, in the first embodiment, when a response indicating that an error has been received is sent from a plurality of terminals, the control station sequentially retransmits the error-received isochronous data to each terminal that is the source of the error-received isochronous data. Although instructions are given, it is also possible to collectively give instructions for resending to each terminal. In the third embodiment, a communication control method capable of collectively inquiring about the success or failure of reception to each terminal and instructing each terminal to resend will be described.
【0114】
(Third Embodiment) FIG. 15 is a schematic diagram for explaining a communication control method according to a third embodiment of the present invention. An example of a wireless narrow network configuration to which the method of FIG. 15 is applied is a new terminal (for example, another computer) added in FIG. The configuration of the wireless communication module 20 mounted on the control station and each terminal in FIG. 2 is shown in FIG. The contents of the program memory 24 of FIG. 3 are shown in FIG. However, the control station program 31 and the terminal program 32 are partially different from the first embodiment.
【0115】
FIG. 15 shows an example of retransmission control in which a reception success / failure inquiry and a retransmission instruction are collectively performed. In FIG. 15, in the isochronous region, first two isochronous blocks (I1-1 and I1-2) are multicast transmitted from the first terminal to the second and third terminals, and then one isochronous block (I2-). 1) is multicast transmitted from the 4th terminal to the 3rd terminal and 5. In the non-isochronous region, the control station first multicasts a packet 90 containing a reception success / failure inquiry to the destinations 2, 3, and 5. The contents of the batch inquiry packet 90 are shown in FIG.
【0116】
As shown in FIG. 16, the batch inquiry packet 90 includes the address 2 of the terminal (that is, the second, third, and fifth terminals to which the isochronous block is transmitted) to which the response packet indicating the success or failure of reception is to be transmitted. The response packet is transmitted with "3" and "5", the addresses "1" and "4" of the terminals to receive the response packet (that is, the first and fourth terminals that are the sources of the isochronous block). The time to be ("t1" ~ "t4") is described.
【0117】
Again, in FIG. 15, when the second, third, and fifth terminals, which are the destinations of the isochronous block, receive the batch inquiry packet 90 as shown in FIG. 16, they are designated to the control station and the designated terminal, respectively. Response packets 91 to 94 are sequentially transmitted at the same time. That is, first, the second terminal receives the isochronous block I1-1 with an error, and sends the response packet 91 indicating that the isochronous block I1-2 is normally received to the control station and the first terminal at the time "t1". Send.
【0118】
Next, the third terminal sends a response packet 92 indicating that both isochronous blocks I1-1 and I1-2 have been received without error to the control station and the first terminal at the time "t2", and further. , The response packet 93 indicating that the isochronous block I2-1 has been received in error is transmitted to the control station and the fourth terminal at the time "t3".
【0119】
Next, the fifth terminal transmits a response packet 94 indicating that the isochronous block I2-1 has been received without error to the control station and the fourth terminal at the time "t4". Upon receiving the response packets 91 to 94 from the second, third, and fifth terminals, the control station collectively instructs the isochronous blocks (I1-1 and I2-1) that received the error to be retransmitted. Packet 95 is multicast-transmitted to the terminals (first and fourth terminals) that are the sources of the block. The contents of the batch retransmission instruction packet 95 are shown in FIG.
【0120】
As shown in FIG. 17, the batch retransmission instruction packet 95 receives the addresses "1" and "4" of the terminals (first and fourth terminals) to be retransmitted and the isochronous data retransmitted by the terminal. The groups you want to have ("Group 1" and "Group 2") and the time when the retransmission should be executed ("t5" and "t6") are described. Here, "group 1" includes the second and third terminals, and "group 2" includes the third and fifth terminals.
【0121】
Again, in FIG. 15, when the first and fourth terminals receive the batch retransmission instruction packet 95 as shown in FIG. 17, they multicast the isochronous block to the terminals included in the specified group at the specified time. resend. That is, the first terminal multicasts the isochronous block I1-1 to the second and third terminals included in "group 1" at the time "t5". The fourth terminal multicasts the isochronous block I2-1 to the third and fifth terminals included in "group 2" at the time "t6".
【0122】
After that, the control station multicasts a batch inquiry packet 96 for inquiring the success or failure of reception to the second and third terminals which are the transmission destinations. In response, the second terminal first sends a response packet 97 indicating successful reception to the control station and the first terminal, and then the third terminal sends a response packet 98 indicating successful reception to the control station and the fourth terminal. Send to the terminal.
【0123】
By the way, in the first embodiment, the control station inquires each terminal to which the isochronous data is transmitted for the success or failure of reception, and each terminal transmits a response packet in response to the inquiry from the control station. , Each terminal may spontaneously transmit a response packet when it receives isochronous data. In the fourth embodiment, a communication control method when each terminal spontaneously transmits a response packet when it receives isochronous data will be described.
【0124】
(Fourth Embodiment) FIG. 18 is a schematic diagram for explaining a communication control method according to a fourth embodiment of the present invention. An example of a wireless narrow network configuration to which the method of FIG. 18 is applied is shown in FIG. The configuration of the wireless communication module 20 mounted on the control station and each terminal in FIG. 2 is shown in FIG. The contents of the program memory 24 of FIG. 3 are shown in FIG. However, the control station program 31 and the terminal program 32 are partially different from the first embodiment.
【0125】
In FIG. 1, in the non-isochronous region, the control station transmits inquiry packets 42 and 44 to the second and fourth terminals to which the isochronous data I1 and I2 are transmitted, and the second and fourth terminals inquire, respectively. Response packets 43 and 45 are being sent accordingly.
【0126】
On the other hand, in FIG. 18, when the terminal (fourth terminal) to which the isochronous block is transmitted receives the isochronous block (I2-1, I2-2 and I2-3), the response packets 100 to 102 voluntarily. Is being sent. Therefore, the control station can omit the inquiry of reception success / failure in the non-isochronous region. Other than this point, it is the same as in FIG.
【0127】
By the way, in the first embodiment, the control station notifies each terminal in advance of the dedicated area information prior to the start of transmission, and each terminal executes the transmission of isochronous data at the time described in the notified information. However, instead, the control station may instruct each terminal to transmit in turn, and each terminal may execute transmission of isochronous data in response to the instruction. In the fifth embodiment, a communication control method for instructing each terminal to transmit isochronous data in order will be described.
【0128】
(Fifth Embodiment) FIG. 19 is a schematic diagram for explaining a communication control method according to a fifth embodiment of the present invention. An example of a wireless narrow network configuration to which the method of FIG. 19 is applied is shown in FIG. The configuration of the wireless communication module 20 mounted on the control station and each terminal in FIG. 2 is shown in FIG. The contents of the program memory 24 of FIG. 3 are shown in FIG. However, the control station program 31 and the terminal program 32 are partially different from the first embodiment.
【0129】
In FIG. 1, the control station notifies each terminal of the dedicated area information 40 in advance prior to the start of transmission, and each terminal executes isochronous data transmission at the time described in the notified information (). See first embodiment). On the other hand, in FIG. 19, in each cycle after the start of transmission, the control station sequentially sends a transmission instruction to each terminal at a time corresponding to each dedicated area, and each terminal sequentially sends a transmission instruction. , The isochronous blocks are transmitted in order according to the instruction.
【0130】
That is, first, the control station sends a transmission instruction 110 to the first terminal at a timing corresponding to Ch.1, and the first terminal transmits the isochronous block I1 accordingly. Next, the control station sequentially sends transmission instructions 111, 112 and 113 to the third terminal at the timing corresponding to Ch.2, and the third terminal responds to the isochronous blocks I2-1, I2-2 and I2-. 3 is being sent in order. Other than the above, it is the same as in FIG. The processing when an error reception of isochronous data (block) occurs is shown in FIG. 5 (see the first embodiment).
【0131】
FIG. 20 is a flowchart showing the operation of the control station. The flowchart of FIG. 20 is similar to the flowchart of FIG. 7 (see first embodiment) except for the following points. In FIG. 7, the control station notifies each terminal in advance of the information regarding the dedicated area allocated in step S4 before the start of transmission (step S5), and then notifies each terminal of the start of the cycle (step S5). Step S6). On the other hand, in FIG. 20, after executing step S4, the control station skips step S5 and executes step S6.
【0132】
After notifying each terminal of the start of the cycle in step S6, the control station sequentially instructs each terminal to transmit isochronous data at the time corresponding to the dedicated area allocated in step S4 (). Step S101). In response to the instruction, each terminal sequentially transmits isochronous data. Then, step S7 and subsequent steps are executed.
【0133】
The operation of the terminal is the same as that of the first embodiment, and is shown in the flowchart of FIG. The details of the data reception process shown in step S26 of FIG. 9 are the same as those of the first embodiment, and are shown in the flowchart of FIG. Since the details of step S22 are partially different from those of the first embodiment, they will be described below.
【0134】
FIG. 21 is a flowchart showing details of the isochronous data transmission process shown in step S22 of FIG. The flowchart of FIG. 21 is similar to the flowchart of FIG. 10 (see first embodiment) except for the following points. In FIG. 10, the terminal first receives the notification of the dedicated area information from the control station (step S41), and waits for the notification of the start of the cycle (step S42). Then, when the start of the cycle is notified, the terminal transmits isochronous data using the allocated dedicated area (step S43).
【0135】
On the other hand, in FIG. 21, step S41 is skipped, and the terminal first executes step S42. Then, when the cycle start is notified, the terminal enters the state of waiting for the transmission instruction (step S121), and when the transmission instruction is received from the control station, the terminal transmits isochronous data (step S122). Then, step S44 and subsequent steps are executed.
【0136】
In the fifth embodiment, the control station inquires about the success or failure of reception to each terminal to which the isochronous data is transmitted, and each terminal transmits a response packet in response to the inquiry from the control station. , Each terminal may spontaneously send a response packet when it receives the isochronous data. FIG. 22 shows a communication control method when each terminal spontaneously transmits a response packet when it receives isochronous data.
【0137】
In FIG. 22, when the fourth terminal receives the isochronous data (I2-1, I2-2 and I2-3), it spontaneously transmits the response packets 120 to 122. Therefore, unlike FIG. 19, the control station can omit the inquiry of reception success / failure in the region in a non-isochronous manner.
[Simple explanation of drawings]
[Figure 1]
It is a schematic diagram for demonstrating the communication control method which concerns on 1st Embodiment of this invention, (A) is a configuration example of a communication control cycle, (B) is a wireless narrow area network of FIG. An example of communication control performed in 9 is shown.
[Figure 2]
It is a figure which shows the configuration example of the wireless narrow area network 9 to which the method of FIG. 1 is applied.
[Fig. 3]
It is a figure which shows the configuration example of the wireless communication module 20 provided in each device (10-14) of FIG.
[Fig. 4]
It is a figure which shows the contents of the program memory 24 of FIG.
[Fig. 5]
It is a schematic diagram for demonstrating the retransmission control performed when the isochronous data (block) is received an error in relation to FIG. 1 (B).
[Fig. 6]
In relation to FIG. 1B, it is a figure which shows how the retransmission of isochronous data is stopped even if the reception error is not resolved when the maximum retransmission time is exceeded.
[Fig. 7]
It is a flowchart which shows the operation of the controller 10 (control station) of FIG.
[Fig. 8]
It is a figure which shows an example of the exclusive area information which is notified to each terminal in step S5 of FIG.
[Fig. 9]
It is a flowchart which shows the operation of each terminal (11-14) of FIG.
[Fig. 10]
It is a flowchart which shows the detail of the isochronous data transmission processing shown in step S22 of FIG.
[Fig. 11]
It is a flowchart which shows the detail of the data reception process shown in step S26 of FIG.
[Fig. 12]
It is a figure which shows the configuration example of the response packet transmitted in step S63 of FIG.
[Fig. 13]
It is a figure which shows how the isochronous data which the determination result of step S8 of FIG. 7 became affirmative and the retransmission was canceled is retransmitted in the non-isochronous region in the next cycle.
[Fig. 14]
It is a schematic diagram for demonstrating the communication control method which concerns on 2nd Embodiment of this invention.
[Fig. 15]
It is a schematic diagram for demonstrating the communication control method which concerns on 3rd Embodiment of this invention.
[Fig. 16]
FIG. 15 is a diagram showing the contents of the batch inquiry packet 90 that the control station is multicast-transmitting.
[Fig. 17]
FIG. 15 is a diagram showing the contents of the batch retransmission instruction packet 95 that the control station is multicast-transmitting.
[Fig. 18]
It is a schematic diagram for demonstrating the communication control method which concerns on 4th Embodiment of this invention.
[Fig. 19]
It is a schematic diagram for demonstrating the communication control method which concerns on 5th Embodiment of this invention, (A) is the configuration example of the communication control cycle, (B) is the line in the network 9 of FIG. An example of communication control is shown.
[Fig. 20]
It is a flowchart which shows the operation (fifth embodiment) of the control station 10 of FIG.
[Fig. 21]
It is a flowchart which shows the detail (fifth embodiment) of the isochronous data transmission processing shown in step S22 of FIG.
[Fig. 22]
FIG. 19B is a diagram showing a communication control method when each terminal spontaneously transmits a response packet when it receives isochronous data in relation to FIG. 19B.
[Fig. 23]
It is a figure which shows the configuration example of the conventional narrow area network 209 compliant with IEEE1394.
[Fig. 24]
It is a schematic diagram for explaining the conventional communication control method by IEEE1394, (A) is a configuration example of the communication control cycle by IEEE1394, and (B) is the communication control performed in the network 209 of FIG. 23. An example is shown.
[Explanation of symbols]
9 ... Wireless narrow network 10 ... Controller (control station) 11 ... Digital Video (Terminal 1) 12 ... Digital TV (Terminal 2) 13 ... Set-top box (3rd terminal) 14 ... Computer (Terminal 4) 20 ... Wireless communication module 21 ... Antenna 22 ... Modulation / demodulation circuit 23 ... processing circuit 24 ... program memory 25 ... I / O circuit 30 ... Basic program 31 ... Program for control station 32 ... Terminal program 40 ... Dedicated area information 41 ... Cycle start packet 42,44 etc ... Inquiry packet 43,45 etc ... Response packet 52,76,77 ... Resend instruction 90,96 ... Bulk inquiry packet 95 ... Batch resend instruction packet 100 ~ 102,120 ~ 122 ... Spontaneous response packet 110 ~ 113 ... Send instruction
6 sheets
Sheet 1 Sheet 2 Sheet 3 Sheet 4 Sheet 5 Sheet 6
Every citation, both ways
| Document | Relation | Office | Cited during |
|---|---|---|---|
| CN114579345A | Cited by | China | Search report |
| WO2005119969A1 | Cited by | World Intellectual Property Organization (WIPO) | International search |
| JPWO2005119969A1 | Cited by | Japan | Examiner |
| JP2002261774A | Cited by | Japan | Search report |
| JP2009147793A | Cited by | Japan | Examiner |
| US9923672B2 | Cited by | United States of America | Applicant |
| US8098636B2 | Cited by | United States of America | Applicant |
| US10454622B2 | Cited by | United States of America | Applicant |
12 members in 6 offices
Priority claims2
| Document | Office | Kind | Date |
|---|---|---|---|
| 2000310392(P2000310392) | Japan | – | |
| 2000310392 | Japan | A |
Members12
| Document | Office | Kind | |
|---|---|---|---|
| CA2358572A1 | Canada | A1 | |
| US2002041586A1 | United States of America | A1 | |
| EP1198096A2 | European Patent Office (EPO) | A2 | |
| CN1348283A | China | A | |
| JP2002190813AThis record | Japan | A | |
| EP1198096A3 | European Patent Office (EPO) | A3 | |
| CN1221103C | China | C | |
| EP1198096B1 | European Patent Office (EPO) | B1 | |
| DE60115575D1 | Germany | D1 | |
| US7085233B2 | United States of America | B2 | |
| DE60115575T2 | Germany | T2 | |
| JP3935698B2 | Japan | B2 |
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Numbers
- Publication
- 2002-190813
- Application
- 309011
Titles2
- Japanese
- 【発明の名称】通信制御方法
- English
- [Title of Invention] Communication control method
Classification
- IPC, 3
- H04L12 28
- H04L29 06
- H04L29 08