COMMUNICATION SCHEME WITH ARBITRATION MECHANISM FOR CASES OF ADDRESS INITIALIZATION AND SERVER SETTING

• US 20080287135A1
• Filed: 07/21/2008
• Published: 11/20/2008
• Est. Priority Date: 07/09/2002
• Status: Active Grant

• Current Assignee: Kabushi Kaisha Toshiba
• Original Assignee: Kabushi Kaisha Toshiba
• Inventors: Teramoto, Keiichi, SAITO, Takeshi, Aizu, Hiroyuki, Kyuma, Shichi, Terashima, Yoshiki
• Granted Patent: US 8,094,655 B2
• Time in Patent Office: Days
• US Class Current: 455/445
• CPC Class Codes: H04L 2101/622 Layer-2 addresses, e.g. medium access control [MAC] addresses
• CPC Class Codes: H04L 61/5092 by self-assignment, e.g. picking addresses at random and testing if they are already in use

Abstract

The other communication devices are prohibited to transmit the address initialization request for a prescribed period of time since one communication device transmitted the address initialization request for an address managed by a control protocol, so that the conflict of the initialization requests for the same address will not occur and the problem of assigning the address in overlap to the communication devices will not arise. Also, the other communication devices are prohibited to transmit the address server detection request packet for a prescribed period of time since one communication device transmitted the address server detection request packet, so that the conflict on the network by a plurality of address server detection requests will not occur, and it is possible to determine the MAC address server uniquely.

Claims

1. A communication system for carrying out communications with other communication devices by using a prescribed control protocol on a network, at least one of the communication devices comprising:

a first tentative address determination unit configured to determine a first tentative address which is a candidate for one of addresses managed by the prescribed control protocol;

a packet transmission unit configured to transmit an address initialization packet containing the first tentative address to the network, in order to check presence/absence of another communication device which is using an address identical to the first tentative address;

a confirmation packet transmission unit configured to transmit an address confirmation packet containing the first tentative address to the network when not receiving, from another communication device within a first prescribed period of time since transmitting the address initialization packet, any of a response packet indicating that an address identical to the first tentative address is currently used, an address initialization packet containing the first tentative address and an address confirmation packet indicating that the first tentative address is determined as an address of the another communication device; and

an address determination unit configured to determine the first tentative address as an address of the communication device, when not receiving, within a second prescribed period of time since transmitting the address initialization packet, any of a response packet indicating that an address identical to the first tentative address is currently used, an address initialization packet containing the first tentative address and an address confirmation packet indicating that the first tentative address is determined as an address of the another communication device,

wherein, when receiving, from another communication device within the first prescribed period of time since transmitting the address initialization packet, any of a response packet indicating that an address identical to the first tentative address is currently used, an address initialization packet containing the first tentative address and an address confirmation packet indicating that the first tentative address is determined as an address of the another communication device, the confirmation packet transmission unit transmits an address confirmation packet containing a second tentative address which is different from the first tentative address to the network, and the use of the first tentative address is prohibited for a period of time no shorter than the first prescribed period of time.

2. The communication device of claim 1, wherein the prescribed control protocol is an Echonet protocol.

3. A communication system for carrying out communications with other communication devices by using a prescribed control protocol on a network, at least one of the communication devices comprising:

a server request transmission unit configured to transmit an address server detection request packet for requesting to become an address server which has a right to determine addresses managed by the prescribed control protocol;

a server determination unit configured to determine the communication device as the address server, when no response packet from another communication device indicating that it is the address server is received within a first prescribed period of time since transmitting the address server detection request packet; and

a control unit configured to control the server request transmission unit in order that, when an address server detection request packet is received from another communication device, the server request transmission unit transmits an address server detection request packet again after a second prescribed period of time which is longer than the first prescribed period of time.

4. The communication device of claim 3, wherein the prescribed control protocol is an Echonet protocol.

5. A communication device for carrying out communications with other communication devices by using a prescribed control protocol on a network, comprising:

a first tentative address determination unit configured to determine a first tentative address which is a candidate for one of addresses managed by the prescribed control protocol;

a packet transmission unit configured to transmit an address initialization packet containing the first tentative address to the network, in order to check presence/absence of another communication device which is using an address identical to the first tentative address and requesting the other communication devices to return information about the addresses being used by the other communication devices;

a confirmation packet transmission unit configured to transmit an address confirmation packet containing the first tentative address to the network when not receiving, from another communication device within a first prescribed period of time since transmitting the address initialization packet, any of a response packet indicating that an address identical to the first tentative address is currently used, an address initialization packet containing the first tentative address and an address confirmation packet indicating that the first tentative address is determined as an address of the another communication device; and

an address determination unit configured to determine the first tentative address as an address of the communication device, when not receiving, within a second prescribed period of time since transmitting the address initialization packet, any of a response packet indicating that an address identical to the first tentative address is currently used, an address initialization packet containing the first tentative address and an address confirmation packet indicating that the first tentative address is determined as an address of the another communication device,

wherein, when receiving, from another communication device within the first prescribed period of time since transmitting the address initialization packet, any of a response packet indicating that an address identical to the first tentative address is currently used, an address initialization packet containing the first tentative address and an address confirmation packet indicating that the first tentative address is determined as an address of the another communication device, and the confirmation packet transmission unit transmits an address confirmation packet containing a second tentative address which is different from the first tentative address to the network,

wherein, within at least the first prescribed period of time after receiving the address initialization packet transmitted from the another communication device, the packet transmission unit is not allowed to transmit, to the network, own address initialization packet containing an address identical to the first tentative address which is contained in the received address initialization packet.

6. The communication device of claim 5, wherein the tentative address determination unit uses a previously used address as the tentative address if the previously used address is maintained, or uses a part of a hardware address of the communication device as the tentative address otherwise.

7. The communication device of claim 5, wherein the second prescribed period of time is longer than the first prescribed period of time.

8. The communication device of claim 5, wherein the packet transmission unit transmits at least one of the address initialization packet and the address confirmation packet to the network for a plurality of times.

9. The communication device of claim 5, wherein the prescribed control protocol is an Echonet protocol.