JP2009188728A - Communicating system and communication adapter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication management device for reducing required power for communication using a plurality of carriers. <P>SOLUTION: Power line communication apparatuses 104, 106 monitor the transfer data amount of data to flow into the apparatuses, calculate the number of required carriers to be required in data communication, based on the transfer data amount, and transmit messages 310, 320 including the number of required carriers to a power line communication apparatus 102 to be functioned as the communication management device. The power line communication apparatus 102 determines a communication carrier to be actually used in communication, based on the respective messages, and transmits an instruction 330 for requesting setting for communication by the communication carrier to the respective power line communication apparatuses. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a communication system that performs communication using a plurality of carriers and a communication adapter included in the communication system.

  Conventionally, many devices that perform communication using a plurality of carriers (carrier waves) such as wireless and wired communication have been proposed. In power line communication (PLC; Power Line Communication) which has been attracting attention in recent years, communication is performed by a plurality of carriers.

  Some ideas for improving the quality of communication using such a plurality of carriers have been proposed so far. For example, the power line communication apparatus described in Patent Document 1 (Japanese Patent Laid-Open No. 2002-319919) calculates the noise characteristics of each carrier, and the transmission rate of transmission data is maximized for each carrier based on the noise characteristics. Since the modulation method is selected, deterioration of communication quality can be improved. Patent Document 1 also describes that the power line communication apparatus prevents useless transmission power consumption by not using a carrier with poor noise characteristics.

Patent Document 2 (Japanese Patent Application Laid-Open No. 2007-96752) discloses a PLC modem that suppresses noise generated by connection of a new electric device to a power line communication network.
JP 2002-319919 A JP 2007-96752 A

  Many communication devices are always used with their power turned on. In particular, a communication device used for a set top box (STB), a router, an IP television, an IP phone, a communication system conversion bridge, or the like needs to be constantly powered.

  Further, the communication device is generally designed so that data can be transferred without any trouble even when the maximum load is applied. That is, it is designed so that communication can be performed with the maximum number of carriers required when the assumed maximum load is applied. Therefore, the communication apparatus always performs modulation over the maximum number of carriers. Moreover, it is always waiting so that any carrier can receive. For example, in high-speed power line communication, 1155 carriers over a frequency range of 1.8 MHz to 30 MHz are constantly modulated or demodulated. For this reason, a great amount of power is consumed because a large amount of calculation and signal output are required even during standby without data exchange. In this way, the power consumption of the communication device designed to always communicate with the maximum number of carriers increases. In addition, the durability of the parts is lowered by constantly supplying power.

  Therefore, in order to reduce power consumption, it is important to improve the carrier operating rate, that is, the ratio of the number of carriers used for data transmission to the maximum number of carriers.

  However, in the conventional technology, since the data transmission state is not determined, the number of carriers necessary for data transmission is not known. Therefore, the number of carriers used for communication is changed according to the data transmission state, and the carrier operation is performed. It was difficult to improve the rate. Here, the data transmission state refers to the amount of data to be communicated or the transfer rate if it is in standby, communicating, or communicating.

  Even if the data transmission state is not determined, for example, the user can change the setting of each device to increase the carrier operating rate. However, changing the settings of each device in accordance with changes in the data transmission state is very complicated and not practical.

  Even if the required number of carriers is known, when changing the number of carriers, synchronization between communication devices included in the same network must be realized. That is, the carrier setting used by the communication sender and the carrier setting used by the receiver must be made common.

  If synchronization is not realized, inconvenience occurs in communication. For example, if data is exchanged between a device that is set to use 30 carriers and another device that is set to use 20 carriers, there is a loss of transmitted data. Can occur. The invention described in Patent Document 1 has the same problem. The power line communication device described in Patent Document 1 does not use a carrier with poor noise characteristics in order to prevent wasteful transmission power consumption. However, if the communication destination device is not synchronized, Loss can occur.

  For the reasons described above, it has been difficult to reduce the power required for communication using a plurality of carriers with the conventional technology.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a communication management apparatus that reduces power required for communication using a plurality of carriers.

  The present invention according to one aspect is a communication system including a plurality of communication adapters, each of which mutually converts a signal of a first communication method and a signal of a second communication method performed by a plurality of carriers. Each communication adapter creates a message related to the transfer data amount based on the transfer data amount and monitoring means for monitoring the transfer data amount of data received from the external device communicating with each communication adapter using the first communication method. Message generating means, and message transmitting means for transmitting the message to a specific communication adapter in the second communication method, wherein the specific communication adapter receives each message based on the message, Determine the required number of carriers required to communicate data using the second communication method, and handle each required number of carriers from a plurality of carriers. Determining means for determining a carrier as the communication carrier, to each communication adapter further includes instruction means for instructing the setting for communicating with the communication carrier.

  Preferably, each communication adapter further includes a first storage means for storing the already assigned communication carrier, and the determining means is still assigned to the communication adapter associated with the message based on the already assigned communication carrier. Assign no communication carrier.

  More preferably, the determining means determines a carrier corresponding to the total number of carriers obtained by adding up the required number of carriers as a communication carrier of all the communication apparatuses.

  More preferably, the message further includes connection information for specifying a data transmission source and a transmission destination, and the determination unit selects a carrier corresponding to the required number of carriers and not yet allocated based on the connection information. And determined as the communication carrier of the transmission destination.

  Preferably, the message creation means calculates the required number of carriers based on the transfer data amount, and creates a message including the required number of carriers.

  More preferably, each communication adapter further includes a second storage unit that stores a table that associates the amount of transfer data with the required number of carriers, and the message creation unit determines the required number of carriers based on the transfer data amount and the table. calculate.

  More preferably, the table reflects error information in which each carrier is associated with an error in each carrier.

  Preferably, the message includes a priority of data communication, and the determining unit determines the communication carrier so that the carrier having higher priority is assigned with priority than the communication having lower priority.

  More preferably, each communication adapter determines the priority according to the priority assigned to the data.

More preferably, each communication adapter sets a priority according to an instruction from the outside.
Preferably, the determination unit regards the communication related to the message received earlier by the reception unit as having a higher priority, and assigns a carrier to the communication with a higher priority in preference to the communication with a lower priority. To determine the communication carrier.

  Preferably, each communication adapter further includes priority storage means for storing priority information indicating the priority of each communication adapter, and the determination means is a communication related to a communication adapter having a high priority based on the priority information. In addition, the communication carrier is determined so that the carrier is preferentially allocated over the communication related to the communication adapter having a low priority.

  Preferably, a priority is set for each communication adapter, and the message includes priority information of each communication adapter, and the determination unit performs communication related to a communication adapter with a high priority based on the priority information. The communication carrier is determined so that the carrier is preferentially assigned over the communication related to the communication adapter with the lower priority.

  Preferably, it further includes priority storage means for storing priority information representing the priority of each data type, the message includes data type information of the data, and the determining means is based on the data type information and the priority information. Thus, a communication carrier is determined so that a carrier is preferentially assigned to data communication with high priority over data communication with low priority.

  More preferably, it further comprises error storage means for storing error information in which each carrier is associated with an error in each carrier, and the determining means is configured to perform communication with low priority based on error information. The communication carrier is determined so that a carrier with fewer errors is allocated.

  Preferably, when the communication carrier exceeds the maximum number of carriers that each communication adapter can use for communication, the determining unit releases the carrier assigned to the communication having the lowest priority.

  Preferably, the determination unit determines a communication carrier while leaving a carrier used for exchange of control information necessary for communication control among a plurality of carriers.

  More preferably, it further comprises error storage means for storing error information in which each carrier is associated with an error in each carrier, and the determination means uses one of a plurality of carriers with few errors for exchanging control information. A communication carrier is determined by leaving it as a carrier.

Preferably, each communication adapter transmits a message every predetermined time.
Preferably, each communication adapter relays a transmission right between communication devices at predetermined time intervals, and each communication adapter transmits a message to a specific communication adapter when receiving the transmission right.

  Preferably, each communication adapter transmits a message corresponding to the maximum transfer data amount among transfer data amounts acquired within a predetermined time.

  Preferably, each communication adapter is a power line communication adapter, and the specific communication adapter is a master device in the power line communication network.

  Preferably, each communication adapter relays the management right every predetermined time between the communication devices, and the one having the management right among the plurality of communication devices is a specific communication adapter.

  Preferably, each communication adapter further includes a switch receiving unit that receives a switching instruction to the power saving mode, and the specific communication adapter transmits a command for starting communication information transmission to each communication device based on the switching instruction. Means for further comprising:

  The present invention according to another aspect is a communication adapter that mutually converts a signal of a first communication method and a signal of a second communication method performed by a plurality of carriers, each of a plurality of other communication adapters Receiving means for receiving a message related to the amount of data transferred from an external device communicating with each other communication adapter using the first communication method from each other communication adapter using the second communication method; And determining means for determining the necessary number of carriers necessary for communicating each data in the second communication method, and determining a number of carriers corresponding to the required number of carriers as a communication carrier from a plurality of carriers. And an instruction means for instructing each communication adapter to set for communication with each communication carrier.

  Preferably, the message includes the required number of carriers calculated by another communication adapter based on the transfer data amount.

  The present invention according to yet another aspect is a communication adapter of a plurality of communication adapters that mutually convert data of a first communication method and data of a second communication method performed by a plurality of carriers. Monitoring means for monitoring the transfer data amount of data received from an external device communicating with each communication adapter using the first communication method, and message creating means for creating a message relating to the transfer data amount based on the transfer data amount; And message transmission means for transmitting the message to the specific communication adapter by the second communication method.

  Preferably, the message creation means calculates the required number of carriers based on the transfer data amount, and creates a message including the required number of carriers.

  Preferably, the specific communication adapter determines a necessary number of carriers for receiving each data by the second communication method based on the message and the receiving means for receiving the message, and from among the plurality of carriers. , Further comprising a determination means for determining the number of carriers corresponding to each required number of carriers as communication carriers, and an instruction means for instructing each communication adapter to set for communication with each communication carrier. A means for changing the communication setting based on the information is further provided.

  The communication management apparatus included in the network according to the present invention can centrally manage the necessary number of carriers determined based on the data transmission state. As a result, according to the present invention, power required for communication using a plurality of carriers can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

(First embodiment)
FIG. 1 is a block diagram showing the configuration of a power line communication system 100 according to the first embodiment. Hereinafter, the configuration of the power line communication system 100 will be described with reference to FIG.

  The power line communication system 100 includes a power line communication device 102 connected to the terminal 120 via the cable 150, a power line communication device 104 connected to the terminal 130 via the cable 150, and a power line communication device 106 connected to the terminal 140 via the cable 150. including. Here, the terminal 120, the terminal 130, and the terminal 140 are a personal computer, an IP telephone, etc., for example. In addition, the cable 150 mediates an Ethernet (registered trademark): Ethernet (registered trademark) signal (hereinafter referred to as an Ethernet (registered trademark) signal), the power line communication device 102, the power line communication device 104, The power line communication device 106 is connected to the power line 110 via the outlet 112, the outlet 114, and the outlet 116 by the plug 103, the plug 105, and the plug 107, respectively.

  Each power line communication apparatus mutually converts an Ethernet (registered trademark) signal and a PLC signal. That is, it has a so-called PLC adapter function. These power line communication devices communicate with each other via the power line 110. On the power line 10, data is transmitted by a plurality of carriers (carrier waves). Moreover, each power line communication apparatus is provided with the function for controlling the carrier used for communication so that it may mention later.

  Of each power line communication device, one device is a master device (CCo; Central Coordinator), and the other device is a slave device (STA; Station). For example, in HomePlugAV, which is one of the power line communication standards, the first activated power line communication device connected to the same power line is the master device. Here, it is assumed that the power line communication device 102 is activated first and the power line communication device 102 becomes a master device. When the power of the master device is turned off, any other device becomes the master device. However, since the method for determining the master device depends on the mounting method, it is not limited to the above.

  In the present embodiment, among the power line communication devices, the device that becomes the master device functions as a communication management device that is a main body of communication management. The master device determines a carrier necessary for communication and instructs each power line communication device to perform communication using the necessary carrier. Here, the “each power line communication device” includes the master device itself.

  FIG. 2 is a block diagram showing a functional configuration of the power line communication apparatus 200 according to the present invention. Hereinafter, the functional configuration of the power line communication apparatus 200 will be described with reference to FIG.

  A power line communication apparatus 200 according to the present invention includes a PLC communication unit 210 that transmits and receives PLC signals on a power line, a signal conversion unit 220 that converts a PLC signal and an Ethernet (registered trademark) signal, and an Ethernet ( An Ethernet (registered trademark) communication unit 230 that transmits and receives (registered trademark) signals, a request generation unit 240 that generates a command for requesting the number of carriers required for communication based on a data communication state, a storage unit 250, Each power line communication apparatus includes an instruction unit 260 that generates a command for instructing the number of carriers used for communication.

  The PLC communication unit 210 includes a PLC reception unit 212 that receives a PLC signal from another power line communication device connected to the power line, and a PLC transmission unit that transmits the PLC signal to another power line communication device connected to the power line. 214.

  The Ethernet (registered trademark) communication unit 230 includes an Ethernet (registered trademark) receiving unit 234 that receives an Ethernet (registered trademark) signal from a terminal connected to the cable, and an Ethernet (registered trademark) to the terminal connected to the cable. And an Ethernet (registered trademark) transmission unit 232 for transmitting signals.

  The signal converter 220 demodulates the PLC signal received by the PLC receiver 212 and transmits the demodulated signal to the Ethernet (registered trademark) transmitter 232. In addition, the signal conversion unit 220 modulates the Ethernet (registered trademark) signal received by the Ethernet (registered trademark) reception unit 234 and transmits the modulated signal to the PLC transmission unit 214. Here, for modulation, a modulation scheme such as orthogonal frequency division multiplexing (OFDM) is used.

  The storage unit 250 stores a correspondence table 252, priority information 254, error information 256, and allocation information 258.

  The correspondence table 252 represents the correspondence between the amount of data to be communicated or the data transfer rate and the number of carriers required for communication. Hereinafter, the data amount and the data transfer rate are collectively referred to as a transfer data amount. The priority information 254 is the priority of each power line communication device or data type in communication. The error information 256 associates each carrier with an error in each carrier. The allocation information 258 is information on a carrier that has been determined by the second determination unit as a communication carrier and has already been allocated for communication. The correspondence table 252, the priority information 254, and the error information 256 may be given in advance or may be updated as needed. For example, the error information and S / N information of each carrier may be monitored and the error information 256 may be updated as needed.

  The request generation unit 240 includes a monitoring unit 242, a carrier calculation unit 244, and a message creation unit 246.

  The monitoring unit 242 monitors the transfer data amount of data flowing into the Ethernet (registered trademark) communication unit 230. The inflowing data specifically refers to data that the power line communication device 200 intends to transmit to another power line communication device. Various kinds of existing techniques can be used as a method for measuring the data transfer rate and data amount.

  The carrier calculation unit 244 calculates the necessary number of carriers necessary for communication of the inflowing data based on the transfer data amount flowing into the Ethernet (registered trademark) communication unit 230. For example, the required number of carriers is calculated by dividing the transfer data amount by the data amount that can be transferred by one carrier. In the case of HomePlugAV, data transfer of about 200 kbps can be performed per carrier. Therefore, when data is transferred at a transfer rate of about 10 Mbps, it is calculated that about 50 carriers are required. Alternatively, the required number of carriers is calculated with reference to the correspondence table 252 stored in the storage unit 250. At this time, the required number of carriers may be calculated in consideration of the error information 256. Further, the correspondence table 252 may reflect error information. For example, when a carrier with many errors is used, the required number of carriers corresponding to the same amount of data is made larger than when a carrier with few errors is used.

  The message creation unit 246 creates a message that tells the master device the required number of carriers calculated by the carrier calculation unit 244 and transmits the message to the signal conversion unit 220. When power line communication device 200 itself is a master device, message creation unit 246 may transmit a message to instruction unit 260 described later without going through signal conversion unit 220.

  Instruction unit 260 includes a determination unit 262 and an instruction generation unit 266. The determination unit 262 determines a communication carrier to be used for communication based on a command from the message creation unit 246 of each power line communication device. The determination unit 262 includes a first determination unit 263 and a second determination unit 264. The 1st determination part 243 acquires the required number of carriers which each power line communication apparatus requests | requires based on each message. The second determination unit 264 selects the number of carriers corresponding to the required number of carriers from the plurality of carriers, and determines the carriers as communication carriers that are actually used in communication. A method for determining a communication carrier from the required number of carriers will be described later. The instruction generation unit 266 creates an instruction for requesting each power line communication device to perform settings for communication using the communication carrier determined by the determination unit 262. Then, the created command is transmitted to the signal converter 220 of another power line communication device via the signal converter 220 and the PLC communication unit 210. Alternatively, the instruction generation unit 266 transmits a command to its own signal conversion unit 220. When receiving the command, the signal conversion unit 220 changes the communication setting. That is, the setting for the carrier to be modulated or demodulated by the signal converter 220 is changed.

  Information exchange between the power line communication apparatuses when determining the communication carrier will be specifically described with reference to FIG. FIG. 3 is a diagram for explaining exchange of information in the power line communication system according to the first embodiment.

  The power line communication device 104 that is a slave device (STA) sends a message 320 that conveys the required number of carriers calculated based on the amount of transfer data flowing into the Ethernet (registered trademark) communication unit 230 to the power line that is the master device (CCo). Transmit to the communication device 102. Similarly, the power line communication apparatus 106 transmits a message 310 that tells the required number of carriers to the power line communication apparatus 102.

  Each power line communication device transmits a message at a predetermined timing. Specifically, for example, messages are transmitted at regular time intervals. In this case, a message notifying the maximum necessary number of carriers calculated within the time interval may be transmitted. By doing in this way, communication can be secured more safely. Alternatively, the message may be transmitted when the monitored data amount or transfer rate change amount exceeds a predetermined threshold. That is, the message creation unit 246 of the power line communication device calculates the change amount based on the data amount or transfer rate monitored by the monitoring unit 242 and transmits a message when the change amount exceeds the threshold value. It is good. According to this configuration, the number of times of message transmission can be reduced. Therefore, the load on the network can be reduced. Alternatively, the transmission right of the message may be relayed between the power line communication devices, and the power line communication device that has received the transmission right may transmit the message.

  The power line communication device 102 which is a master device receives a message indicating the required number of carriers from each power line communication device, and determines a communication carrier based on the required number of carriers. And the instruction | command 330 which requests | requires the setting which communicates with a communication carrier is transmitted to each power line communication apparatus.

  The power line communication device 102 transmits the command at a predetermined timing. Specifically, transmission is performed at regular time intervals. Alternatively, the command may be transmitted without waiting for the required number of carriers.

  According to the power line communication device of the present invention, as described above, it is possible to determine the communication carrier according to the amount of transfer data and dynamically change the communication carrier according to the communication state. Therefore, power consumption can be reduced. In particular, if this power line communication device is introduced into a network including many communication devices having a long standby state, power consumption can be dramatically reduced.

  This will be specifically described with reference to FIG. FIG. 4 is a schematic diagram showing the relationship between the transfer data amount and the carrier used.

  FIG. 4A is a diagram showing the relationship between the transfer data amount and the carrier used in the conventional technique. In the prior art, communication is always performed with the maximum carrier 401 regardless of the amount of transfer data. Therefore, when the amount of transfer data is small, the carrier operating rate is low. For example, according to this communication method, even when data transmission is not performed, communication is performed using a large number of carriers in addition to the minimum control channel 400 necessary for communication between power line communication apparatuses. .

  FIGS. 4B and 4C are diagrams showing the relationship between the amount of transfer data and the number of carriers when the present invention is used. FIG. 4B is a diagram when the amount of transfer data is small. A carrier used for communication includes a control channel 400 and a data carrier 402 for transmitting data. Here, the number of data carriers 402 is small according to the small amount of transfer data. Therefore, the number of carriers used as a whole is also reduced. FIG. 4C is a diagram when the amount of transfer data is large. A carrier used for communication includes a control channel 400 and a data carrier 403. Here, the number of data carriers 403 is large according to the large amount of transfer data. Thus, according to the present invention, since the number of carriers used is changed according to the amount of transfer data, power consumption can be reduced. Further, since the usage rate of components used for modulation / demodulation of the carrier is lowered, the life of the apparatus can be extended.

  Here, returning to FIG. 2, a method by which the determination unit 262 determines a communication carrier will be described.

  The first determination unit 263 included in the determination unit 262 acquires the necessary number of carriers requested by each power line communication device. Specifically, a message notifying the number of necessary carriers transmitted by each power line communication device is received, and the number of necessary carriers is read from the received message. As described above, in the present embodiment, the master device itself is also included in “each power line communication device”.

  In the present embodiment, as described above, a configuration has been shown in which each slave device calculates the required number of carriers. According to this method, since each slave device calculates the required number of carriers and notifies the master device, the calculation load for calculating the required number of carriers can be distributed. However, it may be configured such that each slave device does not calculate the required number of carriers and notifies the master device of a message including information specifying the amount of transfer data. In this case, the first determination unit 263 determines the required number of carriers based on the notified transfer data amount and the correspondence table 252.

  The second determination unit 264 included in the determination unit 262 determines a communication carrier that is actually used for communication based on the required number of carriers determined by the first determination unit 263. The number of communication carriers is determined so as to be as small as possible within a range in which communication is ensured. In addition, in order to prevent data loss, the setting of the carrier used for communication between the sender and the receiver is determined to be the same.

  For example, the 2nd determination part 264 shall determine the total carrier number which totaled each required carrier number as a communication carrier of all the power line communication apparatuses. In any communication, the number of carriers to be used does not exceed the total number of carriers. Thus, if communication carriers are determined in this way, data can be reliably communicated. Further, according to this method, the communication carriers used by the respective power line communication devices are the same, and naturally, the data sender and receiver settings are also common.

  Moreover, the 2nd determination part 264 may determine the number of carriers in detail for every connection instead of allocating the same communication carrier to all the power line communication apparatuses. That is, a communication carrier corresponding to data transmitted / received between them is allocated to a data transmission source and a reception destination. When one power line communication apparatus is related to a plurality of connections, a different carrier is assigned to each connection.

  A specific description will be given with reference to FIG. Consider that the power line communication device 104 transmits first data to the power line communication device 102 and the power line communication device 102 transmits second data to the power line communication device 106.

  The power line communication device 104 calculates the required number of carriers based on the transfer data amount of the first data to be transmitted, and notifies the power line communication device 102 that is the master device. At the same time, the power line communication device 104 notifies the power line communication device 102 of a message including connection information for specifying that the first data relates to the connection between the power line communication device 102 and the power line communication device 104. .

  Moreover, the power line communication apparatus 102 calculates the required number of carriers based on the transfer data amount of the second data to be transmitted. At the same time, the power line communication apparatus 102 acquires connection information for specifying that the second data relates to the connection between the power line communication apparatus 102 and the power line communication apparatus 106 from itself.

  The power line communication apparatus 102 determines a communication carrier based on the required number of carriers and connection information as follows, and issues a communication setting instruction to each power line communication apparatus.

  First, based on the required number of carriers notified from the power line communication device 104, the power line communication device 102 determines the number of first carriers that can ensure communication of the first data. Then, a command requesting communication with the first carrier is transmitted to the power line communication apparatus 102 itself and the power line communication apparatus 104 involved in the communication of the first data.

  Next, based on the necessary number of carriers calculated by itself, power line communication apparatus 102 determines the number of second carriers that can ensure communication of the second data. Here, the second carrier is selected from those not selected as the first carrier. Then, a command for requesting communication using the second carrier is transmitted to the power line communication apparatus 102 itself and the power line communication apparatus 106 involved in the communication of the second data.

  After all, the power line communication device 102 is a carrier that combines the first carrier and the second carrier, the power line communication device 104 is the first carrier, and the power line communication device 106 is the second carrier. Will be.

  Here, the first carrier is determined and then the second carrier is determined. However, there is no problem before and after this unless there are special circumstances. Also, when three or more types of data are exchanged by the same method, a communication carrier can be determined for each connection.

  As described above, according to the method of determining the communication carrier for each connection, each power line communication device only needs to modulate carriers for the data transmitted and received by each power line communication device. Therefore, it is possible to save more power than when a common number of carriers is set for all power line communication apparatuses.

  In order to realize the communication management as described above, it is preferable that a communication path for a message from each slave device to the master device and a setting command from the master device to each slave device is secured. That is, it is preferable that a control channel used for communication of control information, which is information essential for communication control, such as messages and commands, is secured regardless of the amount of transfer data. Therefore, in the present embodiment, the determination unit 262 determines the communication carrier while leaving the control channel. Even when all the power line communication devices in the network are in a standby state in which data is not transmitted and the required number of carriers to be notified is 0, each power line communication device performs modulation / demodulation of the control channel. With this configuration, transmission / reception of instructions between the slave device and the master device is ensured.

  Note that the determination unit 262 preferably determines a carrier with few errors as a control channel. For example, the determination unit 262 refers to the error information 256 and determines the carrier with the least error as the control channel. Since the control channel is always used, the communication quality is improved by determining the control channel in this way.

  By the way, there may be a case where the communication carrier calculated by the above method exceeds the maximum number of usable carriers. Therefore, in such a case, priority may be used so that data is communicated as appropriately as possible.

  For example, each power line communication device may set a priority for the message itself and transmit a message including the communication priority to the master device. It is assumed that the priority of communication can be changed by changing the setting of each power line communication device. Or each power line communication apparatus may determine the priority included in a message based on the priority of the data which each power line communication apparatus receives. For example, when a communication request for high priority data such as VoIP (Voice over Internet Protocol) is received, a high priority message is transmitted.

  The determination unit 262 preferentially allocates a communication carrier for communication related to a message having a high priority.

  For example, when the number of communication carriers exceeds the number of carriers that can be used by each power line communication device, no carrier may be assigned to low priority communication. Specifically, for example, carriers are not allocated in order from the communication with the lowest priority.

  Or it is good also as assigning a carrier in order from communication with a high priority, and allocating the remaining carrier to the power line communication apparatus with a low priority.

  Even if a carrier has already been assigned to a communication with a low priority, the assigned carrier may be released and a carrier may be assigned to a communication with a higher priority. Here, carrier release refers to both release of all carriers and reduction of some carriers.

  In addition, available carriers may be distributed according to priority to determine communication carriers. It is determined that more carriers are assigned to communication with higher priority than communication with lower priority.

  Furthermore, when error information in which each carrier is associated with an error in each carrier is stored in the storage unit 250, a carrier with few errors may be assigned to communication with high priority.

  Further, a carrier may be assigned to communications whose priority is higher than a predetermined level. At this time, the remaining carrier may be assigned to another communication. Also, by setting a plurality of priorities, it becomes possible to assign carriers in stages, and the number of carriers can be used effectively.

  As another example of priority, a priority may be set for a data type. In this case, it is assumed that priority information 254 representing the priority of each data type is stored in the storage unit 250. The message includes information representing the data type. The determination unit 262 determines a communication carrier based on the information indicating the data type included in the message and the priority information 254. How the determination unit 262 reflects the priority of each power line communication apparatus in the determination of the communication carrier is the same as described above.

  As yet another example, the priority of each power line communication device may be used. For example, each power line communication device transmits a message including the priority set uniquely to each power line communication device to the master 0 device, and the determination unit 262 of the master device determines a communication carrier based on the message. . Alternatively, when priority information 254 representing the priority of each power line communication device is stored in storage unit 250, determination unit 262 determines a communication carrier based on priority information 254. How the determination unit 262 reflects the priority of each power line communication apparatus in the determination of the communication carrier is the same as described above.

  As yet another example, communication priority may be determined according to the timing at which a message is received. That is, the determination unit 262 records the timing at which a message generated by each power line communication device is received for communication, and preferentially allocates a communication carrier to communication related to the received message with early timing.

  FIG. 5 is a flowchart showing processing performed by the power line communication apparatus according to the first embodiment. Hereinafter, processing performed by the power line communication apparatus according to the first embodiment will be described with reference to FIG.

  The slave device (STA side power line communication device) is initially in a standby state (step S501). Until the predetermined time has elapsed (NO in step S502), the standby state is maintained. When a certain time has elapsed (YES in step S502), the slave device measures the data transfer rate transferred to the Ethernet (registered trademark) communication unit 230 which is a communication interface (I / F) with the outside in step S503. . Although the data transfer rate is measured here, the data amount of data to be transferred may be measured.

  In step S504, the slave device calculates the required number of carriers based on the data transfer rate. The slave device refers to the table and calculates the necessary number of carriers. Alternatively, the required number of carriers is calculated based on the communication speed expected for each carrier. The details of the calculation method are as described above.

  In step S505, the slave device notifies the master device (CCo-side power line communication device) of the necessary number of carriers. When the slave device notifies the necessary number of carriers, it again returns to the standby state.

  The master device is initially in a standby state (step S506). In step S507, the master device determines whether a message notifying the necessary number of carriers has been received from the slave device. When the message is received (YES in step S507), in step S508, the master device temporarily stores the information on the necessary number of carriers in the storage unit 250, and proceeds to step S509. If the information on the required number of carriers is already stored, it may be updated to the latest information at all times, or stored only when the notified required number of carriers is larger than the required number of carriers already stored. The number of necessary carriers may be updated. In the former case, there is an advantage that the latest communication state is reflected. In the latter case, since the required number of carriers larger than the former is stored, the communication carrier calculated later becomes larger. Therefore, communication can be performed more reliably. If no message has been received (NO in step S507), the process proceeds to step S509 without passing through step S508.

  In step S509, the master device determines whether or not a certain time has elapsed since entering the standby state. If a certain time has not elapsed since entering the standby state (NO in step S509), the process returns to the standby state and the process is repeated. If a certain time has elapsed since entering the standby state (YES in step S509), the process proceeds to step S510.

  In step S510, the master device calculates the required number of carriers. That is, the slave device performs processing similar to the processing performed in steps S503 and S504.

  In step S511, the master device calculates a communication carrier by the method already described based on the required number of carriers received from the slave device and the required number of carriers.

  In step S512, the master device notifies the communication carrier to all power line communication devices including itself. At this time, the allocated communication carrier is stored in the storage unit 250 as allocation information 258. After notification of the communication carrier, the master device returns to the standby state and repeats the above processing.

  In this flowchart, the slave device calculates the required number of carriers at regular time intervals. However, the change amount of the transfer data amount may be monitored constantly or at regular intervals, and the required number of carriers may be calculated when the change amount exceeds a predetermined threshold. According to this configuration, it is possible to reduce the number of required carrier calculations and reduce the calculation load.

  In this flowchart, when the required number of carriers is calculated, the required number of carriers is immediately notified to the master device, but may be notified after waiting for a predetermined time. According to this configuration, it is possible to reduce the number of notifications of the required number of carriers and reduce the load on the network. The slave device may calculate the required number of carriers many times during this waiting time and notify the latest necessary number of carriers. Alternatively, the maximum required number of carriers within the waiting time may be notified. According to the configuration for notifying the latest necessary number of carriers, the latest communication state can be reflected. Moreover, according to the structure which notifies the maximum required carrier number, a communication carrier can be ensured more reliably.

  In addition, the timing at which the master device calculates the communication carrier is not limited to that described in this flowchart. For example, the communication carrier may be calculated as soon as the necessary number of carriers is received without waiting for a certain time. That is, step S509 may be omitted. In this case, if NO in step S507, the process returns to the standby state. Immediately, the latest communication state is reflected by calculating the communication carrier.

  Also, the timing at which the master device communicates with the communication carrier is not limited to the above. Here, the communication carrier is notified to all the power line communication devices immediately after the calculation of the communication carrier, but may be notified at regular intervals.

  As described above, according to the present invention, it is possible to accurately determine the communication state and operate each power line communication device with the optimal communication capability without complicated management by the user. Therefore, the power consumption of each power line communication device can be reduced. In addition, since the present invention is mounted on a communication interface device (communication adapter), it is possible to realize power saving without changing external devices connected to the network such as PCs and IP phones from the conventional ones.

(Second Embodiment)
In the first embodiment, an example is shown in which one master device functions as a communication management device. However, the power line communication device that functions as the communication management device is not limited to the master device. Further, it is not always necessary for one power line communication device to function as a communication management device throughout. In the second embodiment, a system will be described in which a power line communication device that functions as a communication management device changes as the power line communication device relays management rights.

  FIG. 6 is a diagram for explaining exchange of information in the power line communication system according to the second embodiment. The power line communication device 102, the power line communication device 104, and the power line communication device 106 are substantially the same as those in the first embodiment. An IP phone 610 is connected to the power line communication device 104 by a cable 150. In addition, a personal computer 620 is connected to the power line communication device 106 through a cable 150.

  Each power line communication apparatus transmits / receives a management message 630 for exchanging management rights via the power line 110. With this management message 630, the power line communication apparatus having the management right changes at regular intervals. It is assumed that which power line communication device has the management right in what order.

  FIG. 7 is a flowchart showing processing performed by the power line communication apparatus according to the second embodiment. Hereinafter, processing performed by the power line communication apparatus according to the second embodiment will be described with reference to FIG.

  The power line communication device is initially in a standby state (step S701). In step S702, the power line communication apparatus determines whether a management right has been acquired. If the management right has not been acquired (NO in step S702), the process returns to the standby state.

  When the management right is acquired (YES in step S702), in step S703, the data transfer rate transferred to the Ethernet (registered trademark) communication unit 230, which is a communication interface (I / F) with the outside, is measured. Although the data transfer rate is measured here, the data amount of data to be transferred may be measured.

  In step S704, the power line communication device calculates the required number of carriers based on the data transfer rate. For example, the required number of carriers is calculated with reference to a table. Alternatively, the required number of carriers is calculated based on the communication speed expected for each carrier. The details of the calculation method are as described above.

  In step S705, the power line communication apparatus confirms an unused band that is not used for communication, and notifies the all power line communication apparatus of the unused band as a usable band that can be used by another power line communication apparatus.

  In step S706, after waiting for a preset time, the power line communication device relays the management right to the power line communication device that should have the next management right.

  The next power line communication device is also initially in a standby state (step S707). In step S708, the next power line communication apparatus determines whether the use band has been received. If the use band has not been received (NO in step S708), the process returns to the standby state.

  When the use band is received (YES in step S708), the notified band is registered in the available band in step S709.

  Since the next power line communication apparatus is also a power line communication apparatus, the next power line communication apparatus naturally also performs the processing shown in steps S702 to S706. In addition, the power line communication device that has acquired the transmission right performs the same function as the master device in the first embodiment. However, since the use band is not managed by one device, the processing such as step S706, step S708, and step S709 is performed, and the communication carrier is selected from the available bands, so that there is a possibility that the communication carrier overlaps. Eliminated.

(Other embodiments)
In both the first embodiment and the second embodiment, the case where one of the power line communication devices functions as a communication management device has been described. However, the communication management device is different from the power line communication device. It doesn't matter. That is, a device dedicated to managing the number of carriers may be used.

  In any of the embodiments, management of communication in the power line communication system has been described. However, the present invention can also be applied to management of communication performed using a plurality of carriers such as wireless communication and wired communication. In other words, the present invention can be implemented in all communication adapters that mutually convert the signal of the first communication method and the signal of the second communication method performed by a plurality of carriers.

  Further, it is not always necessary for the communication management apparatus to manage the communication carrier as described above. Therefore, a configuration in which a power saving mode in which management is performed and a normal mode in which management is not performed may be switched. For example, each communication device is provided with a power saving mode switch so that when the user presses any power saving switch, an instruction to switch from the normal mode to the power saving mode is transmitted to the communication management device. May be. Upon receiving this instruction, the communication management device changes its own setting and instructs each communication device to shift to the power saving mode. As a result, regardless of which device in the network the power saving switch is pressed, all the devices in the network can quickly enter the power saving mode. Of course, the power management switch may be provided in the communication management device more simply, and the mode may be changed when the switch is pressed. Further, switching from the power saving mode to the normal mode can be realized by the same configuration.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a block diagram showing a configuration of a power line communication system 100 according to a first embodiment. It is a block diagram which shows the functional structure of the power line communication apparatus 200 which concerns on this invention. It is a figure explaining the exchange of information in the power line communication system concerning a 1st embodiment. It is a schematic diagram which shows the relationship between the amount of transfer data and the carrier used. It is the flowchart which showed the process which the power line communication apparatus which concerns on 1st Embodiment performs. It is a figure explaining the exchange of information in the power line communication system which concerns on 2nd Embodiment. It is the flowchart which showed the process which the power line communication apparatus which concerns on 2nd Embodiment performs.

Explanation of symbols

  100 power line communication system, 102, 104, 106 power line communication device, 103, 105, 107 plug, 110 power line, 112, 114, 116 outlet, 120, 130, 140 terminal, 150 cable, 200 power line communication device, 210 PLC communication unit , 220 signal conversion unit, 230 Ethernet (registered trademark) communication unit, 240 request generation unit, 250 storage unit, 260 instruction unit, 310, 320 message, 330 command, 400 control channel, 401 maximum carrier, 402, 403 data carrier.

Claims (29)

A communication system including a plurality of communication adapters, each of which mutually converts a signal of a first communication method and a signal of a second communication method performed by a plurality of carriers,
Each of the communication adapters
Monitoring means for monitoring a transfer data amount of data received from an external device communicating with each of the communication adapters in the first communication method;
Message creating means for creating a message related to the transfer data amount based on the transfer data amount;
Message transmitting means for transmitting the message to the specific communication adapter in the second communication method;
The specific communication adapter is
Receiving means for receiving the message;
Based on the message, a required number of carriers necessary for communicating the data with the second communication method is determined, and the number of carriers corresponding to the required number of carriers is selected from the plurality of carriers. Determining means for determining as the communication carrier;
A communication system further comprising instruction means for instructing each of the communication adapters to set for communication with each of the communication carriers. Each of the communication adapters further includes first storage means for storing the already assigned communication carrier,
The communication system according to claim 1, wherein the determination unit allocates the communication carrier that has not yet been allocated to the communication adapter related to the message based on the communication carrier that has already been allocated.   The communication system according to claim 2, wherein the determination unit determines a carrier corresponding to the total number of carriers obtained by adding the required number of carriers as the communication carrier of all the communication apparatuses. The message further includes connection information for specifying a transmission source and a transmission destination of the data,
The communication system according to claim 2, wherein the determination unit determines, based on the connection information, a carrier corresponding to the required number of carriers and not yet allocated as a communication carrier of the transmission source and the transmission destination. .   5. The communication system according to claim 1, wherein the message creation unit calculates the required number of carriers based on the transfer data amount and creates a message including the required number of carriers. Each of the communication adapters further includes second storage means for storing a table for associating the transfer data amount with the required number of carriers,
The communication system according to claim 5, wherein the message creation unit calculates the required number of carriers based on the transfer data amount and the table.   The communication system according to claim 6, wherein the table reflects error information in which each carrier is associated with an error in each carrier. The message includes a priority of communication of the data;
The said determination means determines the said communication carrier so that the said carrier may be preferentially allocated to the communication with the said high priority rather than the communication with the said low priority. The communication system described.   The communication system according to claim 8, wherein each of the communication adapters determines the priority based on a priority assigned to the data.   The communication system according to claim 8, wherein each of the communication adapters sets the priority according to an instruction from the outside.   The determining unit regards the communication related to the message received earlier by the receiving unit as a higher priority, and prioritizes the communication with the higher priority than the communication with the lower priority. The communication system according to any one of claims 1 to 7, wherein the communication carrier is determined so that the carrier is assigned to the user. Each communication adapter further includes priority storage means for storing priority information representing the priority of each of the communication adapters,
Based on the priority information, the determination means assigns the carrier preferentially to communication related to the communication adapter having a higher priority than communication related to the communication adapter having a lower priority. The communication system according to any one of claims 1 to 7, wherein the communication carrier is determined. A priority is set for each communication adapter,
The message includes priority information of each of the communication adapters,
Based on the priority information, the determination means assigns the carrier preferentially to communication related to the communication adapter having a higher priority than communication related to the communication adapter having a lower priority. The communication system according to any one of claims 1 to 7, wherein the communication carrier is determined. Priority storage means for storing priority information representing the priority of each data type;
The message includes data type information of the data,
The determining means is configured to allocate the carrier preferentially to communication of the high priority data over communication of the low priority data based on the data type information and the priority information. The communication system according to any one of claims 1 to 7, wherein a communication carrier is determined. Further comprising error storage means for storing error information in which each carrier is associated with an error in each carrier;
9. The determination unit determines the communication carrier based on the error information so that the carrier with fewer errors is assigned to the communication with the higher priority than the communication with the lower priority. The communication system according to any one of 1 to 14.   The determination unit releases the carrier allocated to the communication with the lowest priority when the communication carrier exceeds the maximum number of carriers that each communication adapter can use for communication. The communication system according to any one of the above.   The said determination means leaves the carrier used for the exchange of the control information required for the control of the said communication among these carriers, and determines the said communication carrier, Any one of Claim 1-16 Communication system. Further comprising error storage means for storing error information in which each carrier is associated with an error in each carrier;
The communication system according to claim 17, wherein the determination unit determines the communication carrier while leaving the one with the few errors among the plurality of carriers as a carrier used for the exchange of the control information.   19. The communication system according to claim 1, wherein each of the communication adapters transmits the message at a predetermined time. Each of the communication adapters relays a transmission right between the communication devices every predetermined time,
The communication system according to claim 1, wherein each communication adapter transmits the message to the specific communication adapter when receiving the transmission right.   21. The communication system according to claim 19 or 20, wherein each of the communication adapters transmits the message corresponding to the maximum transfer data amount among the transfer data amounts acquired within the predetermined time. Each of the communication adapters is a power line communication adapter,
The communication system according to any one of claims 1 to 21, wherein the specific communication adapter is a master device in a power line communication network. Each of the communication adapters relays a management right every predetermined time between the communication devices,
The communication system according to any one of claims 1 to 21, wherein a device having the management right among the plurality of communication devices is the specific communication adapter. Each of the communication adapters further includes a switching reception unit that receives a switching instruction to the power saving mode,
The communication according to any one of claims 1 to 23, wherein the specific communication adapter further includes means for transmitting a command for starting transmission of the communication information to each of the communication devices based on the switching instruction. system. A communication adapter that mutually converts a signal of a first communication method and a signal of a second communication method performed by a plurality of carriers,
Each of the plurality of other communication adapters sends a message regarding the transfer data amount of data received from the external device communicating with each of the other communication adapters using the first communication method from each of the other communication adapters. Receiving means for receiving the communication method;
Based on the message, a required number of carriers necessary for communicating the data with the second communication method is determined, and the number of carriers corresponding to the required number of carriers is selected from the plurality of carriers. Determining means for determining as the communication carrier;
A communication adapter comprising: instruction means for instructing each of the communication adapters to perform settings for communication with each of the communication carriers.   The message is a communication adapter in which the other communication adapter includes the required number of carriers calculated based on the transfer data amount. One communication adapter among a plurality of communication adapters for mutually converting data of a first communication method and data of a second communication method performed by a plurality of carriers,
Monitoring means for monitoring a transfer data amount of data received from an external device communicating with each of the communication adapters in the first communication method;
Message creating means for creating a message related to the transfer data amount based on the transfer data amount;
A communication adapter comprising: message transmission means for transmitting the message to the specific communication adapter by the second communication method.   28. The communication adapter according to claim 27, wherein the message creation means calculates the required number of carriers based on the transfer data amount and creates a message including the required number of carriers. The specific communication adapter is
Receiving means for receiving the message;
Based on the message, a required number of carriers necessary for communicating the data by the second communication method is determined, and a number of carriers corresponding to the required number of carriers is selected from the plurality of carriers. Determining means for determining as the communication carrier;
Each of the communication adapters further includes instruction means for instructing a setting for communicating with each of the communication carriers,
The communication adapter according to claim 27 or 28, further comprising means for changing a communication setting based on the instruction.

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