JP2006319860A - Power line communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify processing until communication becomes possible and to shorten time required for the processing when a modem for power line communication is newly connected to a power line. <P>SOLUTION: When the new modem E is connected to the power line, the modem E transmits information that informs join of the own modem E to the existing modems A, B on the power line. The modem B near the modem E receives a report of the join from the modem E first, returns a response to the modem E and transmits a link address table which the own modem has. The modem E recognizes that the modem A exists on the power line by the link address table transmitted from the modem B, allocates a link address different from the link addresses of the modems A, B to own modem E to newly create a link address table and transmits the link address of the own modem to the modems A, B. The modems A, B update the address by storing it in own link address tables and after that, all the modems become states of standby for communication. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power line communication (PLC) system configured by connecting a plurality of power line communication modems to a power line, and in particular, when a new power line communication modem is connected to a power line, The present invention relates to a power line communication system that simplifies processing and shortens processing time until a power line communication modem can communicate.

  In recent years, home appliances such as various home appliances have a power line communication function in homes, etc., and monitor and control these home appliances from a master unit constituted by a PC, etc. There has been proposed a system that enables access to the above-described master unit via the Internet, and allows monitoring and controlling home devices from the outside. In addition, it enables high-speed signals to be handled by power line communication, and multimedia information such as video information and audio information from ISPs (Internet Service Providers) via public communication networks including the Internet is real-time A system that enables display on a display device has also been proposed.

  As described above, in order to exchange various signals by power line communication, a power line communication modem is used as an interface between a device that performs signal transmission and reception and the power line. This power line communication modem is generally provided inside an electronic device or the like that is supplied with power via a power outlet, and superimposes a signal from the electronic device on the power line via its own power circuit. In addition, it has a function of separating the signal from the power line and passing it to the electronic device via its own modem.

  FIG. 2 is a block diagram showing a configuration example of a power line communication system according to the prior art. In FIG. 2, 11 to 15 are power line communication modems (hereinafter simply referred to as modems) A to E, 16 is a power line (AC line), 111, 121, 131, 141 and 151 are links (LINK) which each modem has. It is an address table.

  The power line communication system according to the prior art is configured by connecting a plurality of modems A11 to E15 to a power line 16 as a network. Each of the plurality of modems A11 to E15 has a unique MAC address for each modem, and has a link address arbitrarily set for performing communication between the power line communication systems. Each of the plurality of modems A11 to E15 has link address tables 111, 121, 131, 141, 151 in which link addresses of communicable counterpart modems are registered.

  In the example of the power line communication system shown in FIG. 2, each of the plurality of modems A11 to E15 has “xx.xx.xx.00.00.01”, “xx.xx.xx.00.00.02”, “ xx.xx.xx.00.00.03 "," xx.xx.xx.00.00.04 "," xx.xx.xx.00.00.05 ", and link addresses" 000A "," 000B ", It is assumed that “0010”, “0011”, and “0020” are included.

  In the power line communication system configured as described above, it is assumed that only four modems A11 to D14 are connected to the power line 16 as a network and can communicate with each other. In this case, the link address tables 111, 121, 131, 141 of the modems A11 to D14 respectively register the link addresses of modems other than the own modem that is the communication partner.

  Registration of the link address of the partner modem in this link address table is because when a new modem is connected to the power line 16, a report to that effect is sent from the modem and the link address of the modem is transmitted to the power line 16. The modem which has received the report and the link address registers the link address of the new modem received in the link address table in its own modem. At this time, the modem that has received the link address from the new modem transmits the link address of the own modem to the modem newly connected to the power line as a response, and the own modem is stored in the link address table of the other modem. Register the link address.

  As a result of the link address registration process as described above, the link address tables 111, 121, 131, 141 of the modems A11 to D14 and the link address table of the new modem have information other than their own modems as communication partners. The modem's link address is registered to enable communication with each other, and each modem can communicate with each other using the link address of the other party. However, communication between modems cannot be performed until the link address is registered.

  FIG. 3 is a sequence chart for explaining a processing operation until a new power line communication modem becomes communicable when a new power line communication modem is connected to the power line in the power line communication system according to the prior art. A process until a new power line communication modem in the prior art becomes communicable will be described. In the example shown in FIG. 3, the MAC address “xx.xx.” is used as another modem in a state where the power line communication system is constructed by connecting the four modems A11 to D14 to the power line 16 as described above. xx.00.00.05 "and the modem E15 having the link address" 0020 "is an example in the case of trying to connect to the power line 16, but for the sake of simplicity of explanation, the existing model in the case where the modem E15 is connected to the power line 16 is shown. Only the processing sequence between the modems A11, B12 and E15 is shown, but the processing between the existing modems C13, D14 and E15 is similarly performed.

(1) When a new modem E15 is added to the power line 16 and connected, the new modem E15 is connected to the existing modem on the power line 16, that is, in the example shown in FIG. In order to notify that the network has been joined, a message to that effect is transmitted by broadcast (sequence 301).

(2) When the modems A11 and B12 receive the new subscription report from the modem E15 transmitted by broadcast, they return a response to the modem E15 (sequences 303 and 302).

(3) After receiving the response from the modems A11 and B12 in the processing of the sequences 303 and 302, the modem E15 transmits the link addresses used by the modems A11 and B12 to the modems A11 and B12. Then, a “link address request” is transmitted (sequence 304).

(4) Upon receiving the “link address request” in the process of sequence 304, the modems A11 and B12 return the link address assigned to each modem and used to the modem E15. In the example shown in FIG. 3, it is shown that the “link address response” from the modem B12 has reached the modem E15 first, but this assumes that the modem B12 is close to the modem E15 in terms of distance. This is because the “link address request” from the modem E15 is received first and the “link address response” is transmitted (sequences 306 and 305).

(5) When the modem E15 receives the link addresses of the modems A11 and B12 returned from the modems A11 and B12 in the processing of the sequences 306 and 305, the link different from the link addresses assigned to the modems A11 and B12 An address is assigned to its own modem E15, and a new link address table is created (sequence 307).

(6) Thereafter, the modem E15 transmits the link address assigned to itself to the modems A11 and B12 (sequence 308).

(7) When each of the modems A11 and B12 receives the link address of the modem E15 transmitted from the modem E15 in the processing of the sequence 308, it stores the link address in its own link address table and stores the link address table. Update (sequence 310, 309).

(8) Thereafter, each of the modems A11 and B12 notifies the modem E15 that the link address table in the own modem has been normally updated, and transmits a “link completion notification request” to the modem E15 ( Sequence 312, 311, 315, 313).

(9) The modem E15 transmits a “link completion notification response” to each of the “link completion notification requests” from the modems A11 and B12 transmitted in the processes of the sequences 315 and 313 (sequences 316 and 314). ).

(10) After the processing according to the sequence described above is completed, each of the modems A11, B12, and E15 is in a “link establishment complete” state and in a “waiting for communication” state, and can communicate with each other. (Sequences 317 to 319, 320 to 322).

For example, a technique described in Patent Document 1 is known as a conventional technique related to a power line communication system that transmits and receives data using a power line.
JP 2004-7497 A

  In the power line communication system according to the above-described prior art, when a new power line communication modem is connected to the power line, the process according to the sequence described with reference to FIG. 3 is performed until the link establishment is completed including the new modem. Therefore, it is necessary to perform complicated processing, and it takes a lot of time, and there is a problem that communication between modems cannot be performed during that time.

  The object of the present invention is to solve the above-mentioned problems of the prior art, simplify the process until communication is possible, and enable communication when a new power line communication modem is connected to the power line. An object of the present invention is to provide a power line communication system capable of shortening the time required to become.

  According to the present invention, in the power line communication system configured by connecting a plurality of power line communication modems to a power line, each of the plurality of power line communication modems identifies an address of another power line communication modem. A link address table stored as possible, and when a new power line communication modem is connected to the power line, and a notification of a new subscription by broadcast from the new power line communication modem is received, the power line communication is connected to the power line. One of the plurality of power line communication modems has been achieved by transmitting a response to the broadcast and a link address table of the own modem to the new power line communication modem.

  Further, the object is that the new power line communication modem is based on the link address of the modem included in the response from one of the plurality of power line communication modems and the contents of the link address table of the modem. This is achieved by creating a link address table of the own modem, generating a link address of the own modem, and transmitting the generated link address of the own modem to the plurality of power line communication modems.

  In addition, in the above, the object is achieved by that one of the plurality of power line communication modems is a modem close in distance to the new power line communication modem.

  According to the present invention, even when a new power line communication modem is connected to the power line, it is possible to simplify the processing until communication is possible and to shorten the time required until communication is possible. Therefore, communication between the power line communication modems constituting the system can be started in a short time.

  Embodiments of a power line communication system according to the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a sequence chart for explaining processing operations until a new power line communication modem becomes communicable when a new power line communication modem is connected to the power line in the power line communication system according to the embodiment of the present invention. Next, processing until a new power line communication modem in the embodiment of the present invention becomes communicable will be described. Note that the configuration of the power line communication system itself according to the embodiment of the present invention may be the same as that of the related art described with reference to FIG. Accordingly, the processing conditions of the sequence described below are also the same as those in the processing shown in FIG.

(1) When a new modem E15 is added to the power line 16 and connected, the new modem E15 is connected to the existing modem on the power line 16, that is, in the example shown in FIG. In order to notify that the network has been joined, a message to that effect is transmitted by broadcast (sequence 101).

(2) All modems on the power line 16 receive the new subscription report from the modem E15 transmitted by broadcast, but the modem close to the modem E15, for example, the modem B12, first receives the report from the modem E15. Receive a new subscription report. When the modem B12 receives a report of new subscription from the modem E15, the modem B12 returns a response to the modem E15 and transmits a link address table held by the modem B12. At this time, the modem A11 does not transmit any data because the modem B12 transmits the response and the link address table to the modem E15 (sequence 102).

(3) The modem E15 recognizes that the modem A11 exists on the network based on the link address table transmitted from the modem B12, and uses the contents of the link address table and the address of the modem B12 included in the response. A new link address table is created, and a link address different from the link addresses assigned to the modems A11 and B12 is assigned to its own modem E15 (sequence 103).

(4) The modem E15 transmits the link address assigned to the own modem E15 to each of the modem A11 and the modem B12 (sequence 104).

(5) When each of the modems A11 and B12 receives the link address of the modem E15 transmitted from the modem E15 in the process of the sequence 104, the link address of the modem A11 and B12 is stored in its own link address table. The address table is updated (sequences 106 and 105).

(6) After that, each of the modems A11 and B12 notifies the modem E15 that the link address table in the own modem has been normally updated by sending a “link address table update completion” and to the modem E15. On the other hand, a “link completion notification” is transmitted (sequence 109 and 107).

(7) The modem E15 sends a “link completion notification response” to each of “link address table update completion” and “link completion notification” from the modems A11 and B12 transmitted in the processes of the sequences 109 and 107. Transmit (sequence 110, 108).

(8) After the processing according to the sequence described above is completed, each of the modems A11, B12, and E15 is in a “link establishment complete” state and in a “waiting for communication” state, and can communicate with each other. (Sequence 111-113, 114-116).

  According to the embodiment of the present invention that performs processing according to the sequence as described above, when a new modem is connected to a network via a power line, all modems including the new modem perform processing for establishing a link. The number of steps can be simplified to a smaller number of steps compared to the prior art, thereby reducing the time until link establishment, that is, the time during which original communication between modems is impossible. it can.

  The processing in the sequence in the embodiment of the present invention described above can be realized by causing a microprocessor to execute a processing program provided in a memory provided in a power line communication modem.

6 is a sequence chart for explaining processing operations until a new power line communication modem becomes communicable when a new power line communication modem is connected to the power line in the power line communication system according to the embodiment of the present invention. It is a block diagram which shows the structural example of the power line communication system by a prior art. 7 is a sequence chart for explaining processing operations until a new power line communication modem becomes communicable when a new power line communication modem is connected to the power line in the power line communication system according to the prior art.

Explanation of symbols

11-15 Modem A to E for power line communication
16 Power line (AC line)
111, 121, 131, 141, 151 Link (LINK) address table

Claims (3)

  In a power line communication system configured by connecting a plurality of power line communication modems to a power line, each of the plurality of power line communication modems has a link address table in which addresses of other power line communication modems are stored in an identifiable manner. When a new power line communication modem is connected to the power line and a notification of a new subscription by broadcast is received from the new power line communication modem, a plurality of power line communication modems connected to the power line are received. One is a power line communication system, wherein a response to the broadcast and a link address table of the own modem are transmitted to the new power line communication modem.   The new power line communication modem has its own link address table based on the link address of the modem included in the response from one of the plurality of power line communication modems and the contents of the link address table of the modem. 2. The power line communication system according to claim 1, wherein the link address of the own modem is generated, and the link address of the generated modem is transmitted to the plurality of power line communication modems. 3. The power line communication system according to claim 1, wherein one of the plurality of power line communication modems is a modem close in distance to the new power line communication modem.

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