JP4325372B2 - Data distribution method - Google Patents

Description

The present invention relates to a data distribution method for a communication network system in which various devices such as a computer and its peripheral devices are connected via a network, for example, at home, and particularly to other wireless systems such as a television broadcast and a mobile phone system. The present invention relates to a data distribution method for a communication network system capable of performing communication without causing interference.

  Conventionally, a local area network (LAN) system using an existing coaxial cable for receiving television broadcasts is known. For example, Patent Document 1 below discloses a system that realizes television reception, Internet connection, and a private LAN using an existing coaxial cable for television broadcast reception.

JP 2001-358742 A

  By the way, in a conventional system, since a certain specific frequency band is used, it may overlap with a frequency band used by another system.

  In such a case, the signal used by the local area LAN system is transmitted to the outside via an antenna connected to a coaxial cable for receiving television broadcasts, and uses the same frequency as the local area LAN. There is a risk of disturbing communication of other systems.

  For this reason, in the conventional system, there is a problem that a dedicated filter or distributor must be installed in the existing television wiring in order to block the transmission of the signal to the outside and not disturb other systems. there were.

The present invention has been proposed in view of such conventional circumstances, and is a communication network capable of performing communication without changing an existing network and without disturbing other systems. It is an object to provide a data distribution method for a system.

In order to achieve the above object, a data distribution method according to the present invention selects a communication channel having a predetermined frequency bandwidth to be used for communication from at least one data distribution source device to at least one data receiving terminal . In the data distribution method for distributing data, the data distribution source device detects a signal used by another system different from the data distribution source device and the data receiving terminal, and the other system. Collecting usable frequency information relating to usable frequency bands based on information obtained in the step of detecting signals used by the device , calculating usable frequency bandwidths, and the data receiving terminal transmission path at a receiving reception status information, the available frequency band from the reception state information thus received Collect channel characteristic information about sex, and a step of selecting a good communication channel most conditions from the collected channel characteristics information.

  Here, in the present communication network system, the usable frequency information and the transmission path characteristic information can be collected every certain period during communication or whenever a jamming wave is detected.

  In order to achieve the above-described object, a communication channel selection method according to the present invention includes at least one data distribution source device, and at least one data reception terminal connected to the data distribution source device via a network. A communication channel selection method for a communication network system comprising: a usable frequency information collecting step of collecting usable frequency information relating to a usable frequency band by the data distribution source device; the data distribution source device; and A transmission line characteristic information collecting step for collecting transmission line characteristic information related to transmission line characteristics in the usable frequency band by a data reception terminal, and a predetermined information used for communication by the data distribution source apparatus and the data reception terminal. A communication channel selection process for selecting a communication channel of a certain frequency bandwidth. Is shall.

  In such a communication network system and a communication channel selection method thereof, when selecting a communication channel, first, usable frequency information relating to the usable frequency band is collected, and then, regarding transmission path characteristics in the usable frequency band. Transmission path characteristic information is collected, and then a communication channel having a predetermined frequency bandwidth to be used for communication is selected. Also, during communication, a communication channel is selected and reset every fixed time or whenever an interference wave is detected.

According to the data distribution method of the present invention, communication can be performed by selecting a communication channel that does not interfere with other systems and has good frequency characteristics. In addition, even during communication, by selecting and resetting the communication channel at regular time intervals or every time a jamming wave is detected, even if the communication environment changes, interference with other systems can be prevented. Communication can be continued while keeping to a minimum.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

(1) First Embodiment In the first embodiment described first, a communication network system and a communication channel selection method thereof according to the present invention are installed in a home from a server installed in the home. The present invention is applied to a home communication network system that transmits various data such as moving image data to a client terminal. In the present specification, the term “system” represents the entire apparatus constituted by a plurality of apparatuses.

  An example of a frequency band used in the communication network system is shown in FIG. As shown in FIG. 1, in this communication network system, three frequency bands, a frequency band A of 470 MHz to 770 MHz, a frequency band B of 770 MHz to 810 MHz, and a frequency band C of 810 MHz to 960 MHz are used. Further, the frequency bandwidth of the communication channel is assumed to be 20 MHz per channel. However, after collecting usable frequency information as described later, if the usable frequency bandwidth is less than 20 MHz, for example, It is also possible to change settings such as 15 MHz and 10 MHz. Further, in the following description, the frequency band A having the highest frequency band selection priority is defined as frequency band A, and the selection priority is decreased in the order of frequency band B and frequency band C.

  FIG. 2 shows the entire configuration of the communication network system in the first embodiment. As shown in FIG. 2, in the communication network system according to the first embodiment, the server 1 arranged in the room a and the client terminal 2 arranged in the room b are, for example, a coaxial cable for receiving a television broadcast. They are connected via a wired network 5. Specifically, the server 1 is connected to the communication module 3a, and the communication module 3a is connected to the wired network 5 via the connection terminal 4a in the room a. On the other hand, the client terminal 2 is connected to the communication module 3b, and the communication module 3b is connected to the wired network 5 via the connection terminal 4b in the room b. In addition, the server 1 and the client terminal 2 should just have communication functions, such as Ethernet (trademark).

  An example of a functional block configuration of the communication module 3 (3a or 3b) is shown in FIG. As shown in FIG. 3, the communication module 3 includes an I / F 10 that transmits and receives signals to and from an external device via a terminal 16, a memory 12, and a CPU (Central Processing Unit) 13, and executes programs and sets values. And a communication unit 15 connected to the wired network 5 via the terminal 17 and the connection terminal 4a (4b) in the room a (room b) and transmitting / receiving to / from other communication modules. Are connected via a bus 14. Among these, the I / F 10 has a communication function such as Ethernet (registered trademark).

  An example of the configuration of the communication unit 15 in the communication module 3 is shown in FIG. One terminal 17 of the switch 21 in the communication unit 15 is connected to the wired network 5 via a connection terminal 4a (4b) in the room a (room b), and the other terminal is connected to the filter 22 and the transmission circuit unit 33 ( Details are not shown), and data is transmitted to and received from other communication modules.

  The received signal band-limited by the filter 22 is amplified by the amplifier 23 and input to the frequency converter 24. The reception signal input to the frequency converter 24 is mixed with the local oscillation signal input from the local oscillator 29, converted to an IF frequency, and band-limited by the filter 25. The received signal band-limited by the filter 25 is subjected to amplitude adjustment by an automatic gain control amplifier (hereinafter referred to as AGC) 26 as a first path, and then input to the signal processing / control unit 30. Further, the reception signal whose band is limited by the filter 25 is input to the signal processing / control unit 30 via the detector 27 and the level determination unit 28 as the second path. The signal output from the signal processing / control unit 30 is output to the bus 14 via the I / F 31 and the terminal 34.

  Here, the communication unit 15 has four states of a first training mode, a second training mode, a third training mode, and a normal mode, as will be described later. A reception signal received via the terminal 17 in the normal mode is input to the signal processing / control unit 30 via the path 1 described above. On the other hand, the received signal received via the terminal 17 in the first training mode is input to the signal processing / control unit 30 via the path 2 described above. A memory 32 is connected to the signal processing / control unit 30 and is used for applications such as storage of set values and temporary storage of data.

  A processing routine in the communication network system according to the first embodiment will be described below with reference to FIGS.

  First, for the communication module 3a, a processing routine from power-on to transition to the normal mode is shown in the flowcharts of FIGS. 5A and 5B.

  After the power is turned on in step S1, in step S2, signals of other systems existing in the wired network 5 are detected as a first training mode, which will be described in detail later, and usable frequency information is acquired. In subsequent step S3, the communication channel setting of the communication module 3a is confirmed, and in step S4, it is determined whether or not a communication channel is set in the communication module 3a.

If it is determined in step S4 that a communication channel is set (Yes), in step S14, the communication channel is currently available based on the usable frequency information acquired in the first training mode in step S2. It is determined whether or not there is. If it is determined in step S14 that the communication channel cannot be used (No), the processing from step S5 is performed. On the other hand, if it is determined in step S14 that the communication channel is usable (Yes), the communication channel is set in step S15, and the timer is reset to t = ta ₂ in the subsequent step S16. Then, a transmission of a beacon in step S17, the process proceeds to the reception mode in step S18, determines whether it has received an acknowledge ACK ₁ transmitted from the communication module 3b in step S19. Here, the beacon transmitted in step S17 includes information on the network ID set in the communication module 3a, and the acknowledge ACK ₁ includes information on the network ID set in the communication module 3b. To do.

If it is determined in step S19 that the acknowledge ACK ₁ from the communication module 3b has been received (Yes), the network ID is checked in step S20, and it is determined whether or not the network IDs match in step S21. Here, in this communication network system, for example, a network ID used in a network system such as 802.11 can be used. If it is determined in step S21 that the network IDs match (Yes), the processing after step S7 is performed. On the other hand, if it is determined in step S19 that the acknowledge ACK ₁ has not been received (No), the timer is checked in step S23 to determine whether or not a certain time has elapsed, that is, whether ta ₂ is 0. Determine. In step S23, if ta ₂ is not 0 (No), the processing after step S17 is performed. If ta ₂ is 0 (Yes), the processing after step S2 is performed. On the other hand, if it is determined in step S21 that the network IDs do not match (No), the timer is checked in step S24 to determine whether or not a certain time has elapsed, that is, whether ta ₂ is 0 or not. . In step S24, if ta ₂ is not 0 (No), the processing after step S17 is performed, and if ta ₂ is 0 (Yes), the processing after step S2 is performed.

On the other hand, if it is determined in step S4 that the communication channel is not set (No), in step S5, a second training mode process, which will be described in detail later, is performed to collect transmission path characteristic information on usable frequencies. . Subsequently, in step S6, a third training mode, which will be described in detail later, is performed to determine a communication channel to be actually used. Then the timer is reset to t = ta ₁ in step S7, the process proceeds at step S8 in the normal mode. After shifting to the normal mode in step S8, the communication module 3a determines whether or not the power is turned off in step S9. In step S10, the timer is checked to determine whether or not a certain time has elapsed, that is, whether ta ₁ is 0, and in step S11, it is determined whether an interference wave is detected. If it is determined in step S9 that the communication module 3a is powered off (Yes), end processing is performed in step S22. In this termination process, information on the currently used communication channel is stored. If ta ₁ is 0 in step S10 (Yes), or if it is determined in step S11 that an interfering wave has been detected (Yes), it is determined in step S12 whether communication is currently in progress. If it is determined that it is not in the middle (No), the processing after step S2 is performed. On the other hand, if it is determined in step S12 that communication is currently in progress (Yes), after waiting for a predetermined time in step S13, the process returns to step S12 to confirm again whether communication is in progress.

  Next, a processing routine for the communication module 3b from power-on to transition to the normal mode is shown in the flowcharts of FIGS. 6A and 6B.

  After power is turned on in step S31, the communication channel setting of the communication module 3b is confirmed in step S32, and in step S33, it is determined whether or not a communication channel is set in the communication module 3b.

If it is determined in step S33 that the communication channel is set (Yes), the communication channel is set to the frequency in step S39, and the process proceeds to the reception mode in step S40. Then, the timer is reset to t = tb ₁ in step S41, in step S42, it is determined whether or not a beacon has been received. In a case where it is determined that a beacon has not been received in step S42 (No), check the timer at step S46, if the predetermined time has not elapsed, that is, when tb ₁ is not 0 (No), step S40 perform subsequent processing, if tb ₁ is 0 (Yes), performs step S34 and subsequent steps. On the other hand, if it is determined in step S42 that a beacon has been received (Yes), network IDs are checked in step S43, and it is determined in step S44 whether the network IDs match. If it is determined in step S44 that the network IDs match (Yes), after transmitting acknowledge ACK ₁ in step S45, the processing from step S36 is performed, and if it is determined that the network IDs do not match (No). The process after step S34 is performed.

  On the other hand, if it is determined in step S33 that there is no communication channel setting (No), in step S34, a constant output is performed while sweeping (sweeping) the usable frequency as processing in the second training mode, which will be described in detail later. The training signal (reference signal) is transmitted to the communication module 3a at the level. Subsequently, in step S35, a communication channel to be actually used is selected as processing in a third training mode described later in detail.

  In step S36, the normal mode is entered. After shifting to the normal mode, the communication module 3b determines whether or not the power is turned off in step S37. If it is determined in step S37 that the communication module 3a is not turned off (No), the processes in steps S36 and S37 are repeated. If it is determined that the power is turned off (Yes), the process ends in step S38. Process.

  As described above, in the communication network system according to the first embodiment, when a communication channel is not set, first, as a first training mode, signals from other systems are detected to obtain usable frequency information. Next, as the second training mode, the communication module 3b transmits a training signal to the communication module 3a at a constant output level while sweeping the usable frequency, and the communication module 3a obtains the transmission path characteristic information from the reception state. collect. Then, a communication channel to be actually used is selected as the third training mode.

  As a result, communication can be performed by selecting a communication channel that does not interfere with other systems and has good frequency characteristics. In addition, even during communication, by executing the processing in the first to third training modes every certain time or every time a jamming wave is detected, even if the environment during communication changes, Communication can be continued while minimizing interference with the system.

  An example of the processing routine in the first training mode described above will be described in more detail using the flowcharts of FIGS. 7A to 7D.

  In step S51, the communication module 3a sets the reception frequency to the frequency fa1 in the frequency band A. Here, fa1 is assumed to be the lowest frequency in the frequency band A. Subsequently, in step S52, the level of the detected signal (hereinafter referred to as Pdet) is measured, and in step S53, the reference signal level (hereinafter referred to as Pref) is compared with Pdet, and Pdet is greater than Pref. Determine whether it is larger. If it is determined in step S53 that Pdet is larger than Pref (Yes), in step S54, frequency information and level determination value = 1 are recorded in a register in the memory of the communication module 3a. On the other hand, if it is determined in step S53 that Pdet is equal to or less than Pref (No), in step S55, frequency information and level determination value = 0 are recorded in the register.

  Next, in step S56, the frequency is changed to f + s1. Here, s1 is a frequency step width, and has a value sufficiently smaller than the frequency bandwidth of the communication channel used for communication. Subsequently, the frequency f set in step S57 is compared with fa2, and it is determined whether f is fa2 or less. Here, fa2 is assumed to be the highest frequency in the frequency band A. If f is fa2 or less in step S57 (Yes), the processing from step S52 to step S56 is performed again to detect the signal at the set frequency. On the other hand, if f is larger than fa2 (No) in step S57, information in the register is searched for in step S58 to calculate the usable frequency bandwidth. In step S59, it is determined whether or not the usable frequency bandwidth B is 20 MHz or more. If it is determined in step S59 that the usable frequency bandwidth B is 20 MHz or more (Yes), a provisional channel to be used in the second training mode is determined in step S60. On the other hand, if it is determined in step S59 that the usable frequency bandwidth B is smaller than 20 MHz (No), the maximum usable frequency bandwidth (Ba) in the frequency band A is recorded in step S61.

  Next, in step S62, the communication module 3a sets the reception frequency to the frequency fb1 in the frequency band B. Here, fb1 is assumed to be the lowest frequency in the frequency band B. Thereafter, in steps S63 to S72, the same processing routine as that for the frequency band A in steps S52 to S61 described above is performed for the frequency band B. In step S70, it is determined whether or not the usable frequency bandwidth B is 20 MHz or more. If it is determined in step S70 that the usable frequency bandwidth B is 20 MHz or more (Yes), a provisional channel to be used in the second training mode is determined in step S71. On the other hand, if it is determined in step S70 that the usable frequency bandwidth B is smaller than 20 MHz (No), the maximum usable frequency bandwidth (Bb) in the frequency band B is recorded in step S72.

  Next, in step S73, the communication module 3a sets the reception frequency to the frequency fc1 in the frequency band C. Here, fc1 is assumed to be the lowest frequency in the frequency band C. Thereafter, in steps S74 to S83, the same processing routine as that for the frequency band A in steps S52 to S61 described above is performed for the frequency band C. In step S81, it is determined whether or not the usable frequency bandwidth B is 20 MHz or more. If it is determined in step S81 that the usable frequency bandwidth B is 20 MHz or more (Yes), a provisional channel to be used in the second training mode is determined in step S82. On the other hand, if it is determined in step S81 that the usable frequency bandwidth B is smaller than 20 MHz (No), the maximum usable frequency bandwidth (Bc) in the frequency band C is recorded in step S83.

  When the processing from the frequency band A to the frequency band C is completed, in step S84, Ba and Bb are compared to determine whether Ba is larger than Bb. If it is determined in step S84 that Ba is larger than Bb (Yes), a provisional channel to be used in the second training mode is determined within the frequency band A in step S85. On the other hand, if it is determined in step S84 that Ba is equal to or less than Bb (No), in step S86, Bb and Bc are compared to determine whether Bb is greater than Bc. If it is determined in step S86 that Bb is larger than Bc (Yes), a provisional channel to be used in the second training mode is determined in the frequency band B in step S87. On the other hand, if it is determined in step S86 that Bb is equal to or less than Bc (No), a provisional channel to be used in the second training mode is determined within the frequency band C. When determining a provisional channel, a plurality of communication channel candidates are prepared in the usable frequency band determined in the first training mode as described above, and a provisional channel is selected from among them. Can take the way.

  As described above, in the first training mode, usable frequency information is collected, and a frequency band to be used (any one of frequency bands A, B, and C) is selected according to the priority order. At this time, if the usable frequency bandwidth is less than 20 MHz in any frequency band, the frequency band to be used is selected in consideration of the priority order of the frequency bands and the respective maximum usable frequency bandwidths. Furthermore, in the first training mode, a provisional channel is selected within the frequency band to be used. This provisional channel is provisionally used only for communication between the communication module 3a and the communication module 3b in the second training mode described later.

  An example of the processing routine in the second training mode described above will be described in more detail using the flowcharts of FIGS. 8A to 9F.

  First, an example of the processing routine of the communication module 3a in the second training mode is shown in FIGS. 8A and 8B.

In step S91, the communication module 3a sets the frequency f to the frequency ftmp of the provisional channel determined in the first training mode. Subsequently, after transmitting a beacon in step S92, the process shifts to a reception mode in step S93, and it is determined whether or not an acknowledge ACK ₂ transmitted from the communication module 3b is received in step S94. If it is determined in step S94 that the acknowledge ACK ₂ has not been received (No), the processing from step S92 to step S94 is repeated. On the other hand, if it is determined in step S94 that the acknowledge ACK ₂ has been received (Yes), the network ID is checked in step S95, and it is determined in step S96 whether the network IDs match. If it is determined in step S96 that the network IDs do not match (No), the processing from step S92 to step S96 is repeated. On the other hand, if it is determined in step S96 that the network IDs match (Yes), the timer is reset to t = ta ₃ in step S97.

Next, in step S98, channel information is transmitted, and in step S99, it is determined whether or not an acknowledge ACK ₃ transmitted from the communication module 3b has been received. If it is determined in step S99 that the acknowledge ACK ₃ has not been received (No), the timer is checked in step S110. If a predetermined time has not elapsed, that is, if ta ₃ is not 0, steps S99 and The process of step S110 is repeated. On the other hand, when it is determined that ta ₃ is 0 at step S110 (Yes), it performs step S92 and subsequent steps. On the other hand, if it is determined in step S99 that the acknowledge ACK ₃ has been received, the counter is reset to Na = 1 in step S100, and the frequency is set to f (Na) in step S101. Here, f (Na) is a usable communication channel in the use frequency band (any of frequency bands A, B, and C) determined in the first training mode. Here, it is assumed that Na = 0. It is assumed that the lowest frequency among the usable frequencies is selected, and that the frequency increases as Na increases. Then, the process proceeds to the reception mode in step S102, the timer is reset to t = ta ₄ in step S103.

In step S104, it is determined whether a training signal has been received. If it is determined in step S104 that the training signal has not been received (No), the timer is checked in step S111. If a predetermined time has not elapsed, that is, if ta ₄ is not 0, the process proceeds to step S104. Repeat the process. On the other hand, if it is determined in step S104 that the training signal has been received (Yes), the reception level of the training signal is measured in step S105, and recording is performed in step S106, so that transmission path characteristic information in the used frequency band is obtained. To collect.

Subsequently, after transmitting acknowledge ACK ₄ in step S107, the count value Na is incremented by 1 in step S108. In step S109, it is determined whether or not Na is larger than the maximum value Na (max). If Na is equal to or less than Na (max) (No), the processing from step S101 is performed, and Na is Na If it is greater than (max) (Yes), this routine is terminated. However, Na (max) is equal to the number of usable frequencies determined in the first training mode.

  Subsequently, an example of a processing routine of the communication module 3b in the second training mode is illustrated in FIGS. 9A to 9F.

In step S121, the communication module 3b is shifted to the reception mode, the timer is reset to t = _{tb 11} in step S122. In step S123, the frequency band A is searched. In step S124, it is determined whether or not a beacon from the communication module 3a has been received. If it is determined in step S124 that a beacon has not been received (No), the timer is checked in step S139. If a predetermined time has not elapsed, that is, if tb ₁₁ is not 0 (No), The process of S123 and step S124 is performed. On the other hand, if it is determined in step S139 that tb ₁₁ is 0 (Yes), the frequency band B is searched after step S142. On the other hand, if it is determined in step S124 that a beacon has been received (Yes), network IDs are checked in step S125, and it is determined in step S126 whether the network IDs match. If it is determined in step S126 that the network IDs do not match (No), the processing from step S121 is repeated. On the other hand, if it is determined in step S126 that the network IDs match (Yes), acknowledge ACK ₂ is transmitted in step S127. Then, the timer is reset to t = _{tb 12} in step S128, it resets the counter to Na = 1 in step S129.

Next, in step S130, it is determined whether or not channel information transmitted from the communication module 3a has been received. If it is determined in step S130 that the channel information has not been received (No), the timer is checked in step S140. If a predetermined time has not elapsed, that is, if tb ₁₂ is not 0 (No), The process of step S130 is performed. On the other hand, if it is determined in step S140 that tb ₁₂ is 0 (Yes), the processing after step S121 is performed. On the other hand, if it is determined in step S130 that channel information has been received (Yes), acknowledgment ACK ₃ is transmitted in step S131. Then, set the frequency to f (Na) in step S132, the timer is reset to t = _{tb 13} in step S133.

Next, in step S134, a training signal is transmitted to the communication module 3a while sweeping at a constant output level. Thereafter, the process shifts to the reception mode in step S135, and it is determined whether or not the acknowledge ACK ₄ is received in step S136. If it is determined in step S136 that the acknowledge ACK ₄ has not been received (No), the timer is checked in step S141, and if a predetermined time has not elapsed, that is, if tb ₁₃ is not 0 (No). The process after step S132 is performed. On the other hand, if it is determined in step S141 that tb ₁₃ is 0, the processes in and after step S121 are performed. On the other hand, if it is determined in step S136 that the acknowledge ACK ₄ has been received (Yes), the count value Na is incremented by 1 in step S137. In step S138, it is determined whether or not Na is greater than the maximum value Na (max). If Na is equal to or less than Na (max) (No), the processing from step S132 is performed, and Na is Na ( If it is greater than (max) (Yes), this routine is terminated.

  Similarly, processing for frequency band B is performed in steps S142 to S162, and processing for frequency band C is performed in steps S163 to S183.

  As described above, in the second training mode, first, the communication module 3a transmits a beacon on the provisional channel in the use frequency band selected in the first training mode, and then the communication module 3b sequentially scans from the frequency band A. The training signal is transmitted to the communication module 3a while sweeping at a constant output level for the frequency band in which the beacon is received. The communication module 3a measures and records the reception level of this training signal, and collects transmission path characteristic information in the frequency band.

  An example of the processing routine in the third training mode described above will be described in more detail with reference to the flowcharts of FIGS.

  First, an example of the processing routine of the communication module 3a in the third training mode is shown in FIG.

  In step S191, the communication module 3a reads the signal level information at each frequency recorded in the second training mode, and selects the communication channel with the best condition. For example, when the frequency characteristic of the transmission path predicted from the data read in step S191 is as shown in FIG. 12, and the black region in the figure is an unusable frequency acquired in the first training mode, From the frequency bandwidth information acquired in the first training mode and the transmission path characteristic information collected in the second training mode, the communication channel x with the best condition is selected, and the communication channel to be used is determined in step S192.

In step S193, channel information related to the determined communication channel is transmitted to the communication module 3b. At this time, the frequency used last during the processing in the second training mode is used, and information is transmitted. Subsequently, in step S194, the mode is shifted to the reception mode, and in step S195, it is determined whether or not the acknowledge ACK ₅ transmitted from the communication module 3b is received. If it is determined in step S195 that the acknowledge ACK ₅ has been received (Yes), the communication channel is changed in step S196, and this routine is terminated. On the other hand, if it is determined in step S195 that the acknowledge ACK ₅ has not been received (No), the processing from step S193 is performed.

  Next, FIG. 11 shows an example of the processing routine of the communication module 3b in the third training mode.

In step S201, the communication module 3b resets the timer to t = ta ₅ , and shifts to the reception mode in step S202. Subsequently, in step S203, it is determined whether or not channel information from the communication module 3a has been received. If it is determined in step S203 that channel information has not been received (No), the timer is checked in step S206, and if a certain time has not elapsed, that is, if ta ₅ is not 0 (No), The process of step S201 is performed. On the other hand, if it is determined in step S206 that ta ₅ is 0 (Yes), the communication module 3b is reset in step S207, and then this routine is terminated. On the other hand, if it is determined in step S203 that channel information has been received (Yes), acknowledgment ACK ₅ is transmitted in step S204, the communication channel is changed in step S205, and this routine is terminated.

  As described above, in the third training mode, the communication module 3a selects the communication channel with the best condition from the frequency bandwidth information collected in the first training mode and the transmission path characteristic information collected in the second training mode. Then, channel information relating to this communication channel is transmitted to the communication module 3b.

(2) Second Embodiment In the first embodiment described above, the case where only one client terminal 2 exists in the communication network system has been described. However, the present invention is not limited to this, and a plurality of client terminals 2 are not limited. There may be a client terminal.

  FIG. 13 shows the overall configuration of a communication network system according to the second embodiment in which a plurality of client terminals are present. As shown in FIG. 13, the communication network system in the second embodiment includes a server 1 arranged in a room a, a client terminal 2a arranged in a room b, and a client terminal 2b arranged in a room c. For example, it is connected via a wired network 5 such as a television broadcast receiving coaxial cable. Specifically, the server 1 is connected to the communication module 3a, and the communication module 3a is connected to the wired network 5 via the connection terminal 4a in the room a. On the other hand, the client terminal 2a is connected to the communication module 3b, and this communication module 3b is connected to the wired network 5 via the connection terminal 4b in the room b. The client terminal 2b is connected to the communication module 3c, and the communication module 3c is connected to the wired network 5 via the connection terminal 4c in the room c.

  Here, when the client terminal 2b participates in the communication network, the network ID matches with the network ID included in the beacon transmitted from the communicating communication module 3a and the channel information regarding the communication channel used. In this case, it is possible to participate in a communication network by setting a frequency for a given communication channel.

(3) Third Embodiment In the above-described first embodiment, only signals of other systems existing in the wired network 5 can be detected. However, in an actual environment, since signals of other systems exist regardless of inside or outside of the wired network 5, it is necessary to detect signals of other systems existing outside the wired network 5.

  Therefore, by changing the configuration of the communication module 3a as shown in FIG. 14, it is possible to detect signals of other systems existing outside the wired network 5. As illustrated in FIG. 14, the communication module 3 includes a switch 18, a terminal 19, and an antenna 20 in addition to the functional block configuration of the communication module 3 illustrated in FIG. 3. The switch 18 is connected to the wired network 5 through the terminal 17 and is connected to the antenna 20 through the terminal 19.

  By adopting such a configuration, in the first training mode described above, signals of other systems in the wired network 5 are detected, and signals of other systems existing outside the wired network 5 are detected in a time division manner. It becomes possible to detect signals of other systems existing inside and outside the wired network 5.

(4) Fourth Embodiment In the first embodiment described above, when the communication unit 15 of the communication module 3 detects a signal of another system, the path 2 in FIG. Was used to detect the signal level. On the other hand, the signal processing / control unit 30 adjusts the amplification level of the AGC 26 by detecting the level of the signal input through the path 1 and keeps the signal level input to the signal processing / control unit 30 constant. Has the function to keep. Therefore, the input power level may be detected by detecting the control voltage applied to the AGC 26.

(5) Fifth Embodiment In the first embodiment described above, when the interference wave is detected in the normal mode, for example, as shown in the flowcharts of FIG. 5A and FIG. Although it has been described that the process is performed again from the process and a new communication channel is determined, it may be further simplified as shown in the flowchart of FIG.

  That is, in step S211, the communication module 3a performs communication in the normal mode. In step S212, the communication module 3a determines whether a signal used by another system is detected as an interference wave. If it is determined in step S212 that no interfering wave has been detected (No), the process of step S211 is performed. If it is determined that an interfering wave has been detected (Yes), the processes in and after step S213 are performed.

  In step S213, the third training mode is performed to select a new communication channel. Here, in the third training mode in step S213, the frequency band that has been used until the jamming wave is detected and until the jamming wave is detected from the usable frequencies detected in the first training mode. It is assumed that selection is made from among communication channels excluding the communication channel used. When a communication channel is selected in step S213, the mode is changed to the normal mode in step S214, and communication is continued.

  As described above, according to the fifth embodiment, when an interference wave is detected, a communication channel to be used next can be selected without performing all the processing in the first to third training modes.

  According to the present invention described above, for example, when communication is performed in the home using the UHF band used in television broadcasting or the like, the channel used in UHF television broadcasting differs from region to region. Even when it is necessary to set a frequency channel to be used in advance for each region, it is possible to use the device without preparing a dedicated communication module for each region. In addition, even if there is a change in the channel of the television broadcast in the future, it becomes possible to continue home communication without affecting the television broadcast after the change.

It is a figure which shows an example of the frequency band used in a communication network system. It is a figure which shows the whole structure of the communication network system in 1st Embodiment. It is a figure which shows an example of the functional block structure of a communication module. It is a figure which shows an example of a structure of the communication part in the communication module. It is a flowchart explaining the processing routine until it transfers to normal mode about a server side communication module from power activation. It is a flowchart explaining the processing routine until it transfers to normal mode about a server side communication module from power activation. It is a flowchart explaining the processing routine until it transfers to normal mode from power activation about the communication module by the side of a client terminal. It is a flowchart explaining the processing routine until it transfers to normal mode from power activation about the communication module by the side of a client terminal. It is a flowchart explaining an example of the process routine in 1st training mode. It is a flowchart explaining an example of the process routine in 1st training mode. It is a flowchart explaining an example of the process routine in 1st training mode. It is a flowchart explaining an example of the process routine in 1st training mode. It is a flowchart explaining an example of the processing routine of the server side communication module in 2nd training mode. It is a flowchart explaining an example of the processing routine of the server side communication module in 2nd training mode. It is a flowchart explaining an example of the processing routine of the communication module by the side of a client terminal in 2nd training mode. It is a flowchart explaining an example of the processing routine of the communication module by the side of a client terminal in 2nd training mode. It is a flowchart explaining an example of the processing routine of the communication module by the side of a client terminal in 2nd training mode. It is a flowchart explaining an example of the processing routine of the communication module by the side of a client terminal in 2nd training mode. It is a flowchart explaining an example of the processing routine of the communication module by the side of a client terminal in 2nd training mode. It is a flowchart explaining an example of the processing routine of the communication module by the side of a client terminal in 2nd training mode. It is a flowchart explaining an example of the processing routine of the server side communication module in 3rd training mode. It is a flowchart explaining an example of the processing routine of the communication module by the side of a client terminal in 3rd training mode. It is a figure explaining the frequency characteristic of a transmission line, and the communication channel selected. It is a figure which shows the whole structure of the communication network system in 2nd Embodiment. It is a figure which shows an example of the functional block structure of the communication module in 3rd Embodiment. In a 5th embodiment, it is a flow chart explaining an example of a processing routine of a communication module on the server side when an interference wave is detected.

Explanation of symbols

  1 server, 2, 2a, 2b client terminal, 3, 3a, 3b communication module, 4a, 4b, 4c connection terminal, 5 wired network, 10 I / F, 11 control unit, 12 memory, 13 CPU, 14 bus, 15 Communication unit, 16, 17 terminal, 18 switch, 19 terminal, 20 antenna, 21 switch, 22 filter, 23 amplifier, 24 frequency converter, 25 filter, 26 automatic gain control amplifier, 27 detector, 28 level discriminator, 29 Local oscillator, 30 signal processing / control unit, 31 I / F, 32 terminals, 33 transmission circuit unit, 34 terminals

Claims (7)

In a data distribution method for selecting a communication channel having a predetermined frequency bandwidth to be used for communication from at least one data distribution source device to at least one data receiving terminal , and distributing data,
A step of detecting a signal used by another system different from the data distribution source device and the data receiving terminal by the data distribution source device;
Collecting usable frequency information related to usable frequency bands based on information obtained in the step of detecting signals used by the other systems, and calculating usable frequency bandwidths;
Receiving the reception status information of the data receiving terminal;
And a step of selecting a good communication channel most conditions from the transmission path characteristic information was collected, the transmission path characteristic information collected about the channel characteristics from the received status information in the available frequency band thus received
Data delivery method . If the usable frequency bandwidth calculated in the step of calculating the usable frequency bandwidth is less than the predetermined frequency bandwidth of the communication channel, the maximum usable frequency bandwidth is calculated and communication is performed. The communication channel to use
The data distribution method according to claim 1 . The data receiving terminal transmits a reference signal to the data distribution source device at a constant output level while sweeping the usable frequency band,
The data distribution source apparatus, based on the reception result of the reference signal, the data distribution method of claim 1, wherein to gather the channel characteristic information. The available frequency information and data distribution method according to claim 1, wherein to gather the channel characteristic information for each predetermined period during communication. 2. The data distribution method according to claim 1, wherein when an interference wave is detected during communication, the usable frequency information and the transmission path characteristic information are collected again. Above when the width of the available frequency band is less than the predetermined frequency bandwidth, data distribution method according to claim 1, wherein to change the frequency bandwidth of the communication channel you use to communicate. The data distribution source device can be connected to a new data receiving terminal,
The data distribution source device transmits channel information related to a communication channel in use to the new data receiving terminal,
The new data receiving terminal, data distribution method intends line communication in the communication channel according to claim 1, wherein in response to the transmitted channel information.

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