Radio communication device

• US 20030124979A1
• Filed: 12/24/2002
• Published: 07/03/2003
• Est. Priority Date: 12/28/2001
• Status: Active Grant

• Current Assignee: Godo Kaisha IP Bridge 1 (IP Bridge, Inc.)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Tamura, Toshiya, Tanada, Tosaku, Aoki, Takayasu, Nagahama, Kentaro, Matsuya, Hiroshi
• Granted Patent: US 7,164,887 B2
• Time in Patent Office: Days
• US Class Current: 455/41.1
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 84/10 Small scale networks; Flat hierarchical networks
• CPC Class Codes: H04W 84/20 Master-slave selection or change arrangements
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

The positional relationship between a master terminal and a slave terminal and the positional relationship of the slave terminal with the master terminal and with other slave terminals are measured, and a slave terminal subject to switching to master terminal is selected using the positional relationship. A network is then reconstructed with the slave terminal subject to switching selected in this manner as the new master terminal, and as a result the terminals forming the network prior to switching are prevented from falling outside of the communication range of the new master terminal and short range radio communication is maintained with the same terminals as those prior to switching.

Claims

1. A radio communication device which operates as master terminal to form a network with another radio communication devices using a short range radio communication function, comprising:

a positional relationship measuring unit that measures positional relationship between the radio communication device operating as master terminal and the another radio communication devices operating as slave terminals;

a switch timing judgment unit that judges timing of a switch in communication mode using the positional relationship;

a positional relationship information processing unit that requests the another radio communication devices to notify positional relationship information indicating the positional relationship between the another radio communication devices and each of the terminals forming the network, and receives the positional relationship information notified from the radio communication devices;

a switching subject terminal determining unit that selects a radio communication device subject to switching using the positional relationship information; and

a communication mode switching processing unit that switches to a communication mode in which the radio communication device subject to switching is set to operate as a new master terminal.

6. The radio communication device according to claim 1, wherein the switch timing judgment unit judges that it is time to switch communication mode when the radio communication device operating as slave terminal moves outside of the communication range of the radio communication device operating as master terminal.

7. The radio communication device according to claim 1, wherein the positional relationship information received by the positional relationship information processing unit includes the number of terminals included within the communication ranges of the radio communication devices which are the sources of the notification of the positional relationship information, and

wherein the switching subject terminal determining unit determines as the radio communication device subject to switching the radio communication device which includes, within the communication range thereof, the largest number of the terminals forming the network.

9. The radio communication device according to claim 1, wherein the positional relationship information received by the positional relationship information processing unit includes the number of terminals included within the communication ranges of the radio communication devices which are the sources of the notification of the positional relationship information and information regarding the distances between the notification source radio communication devices and the another terminals included within the communication ranges thereof, and

wherein the switching subject terminal determining unit determines the radio communication device subject to switching on the basis of the number of terminals and the distance information.

11. The radio communication device according to claim 1, wherein the communication mode switching processing unit:

transmits a communication mode switching request to the radio communication device subject to switching;

notifies the radio communication device subject to switching of identifiers for the terminals forming the network after the radio communication device has consented to switching;

disconnects the network after providing notification of the identifiers; and

switches to a communication mode in which the radio communication device subject to switching is set to operate as master terminal.

12. The radio communication device according to claim 1, wherein the communication mode switching processing unit:

issues a command for communication mode switching to the radio communication device subject to switching;

provides notification of identifiers for the terminals forming the network;

disconnects the network after providing notification of the identifiers; and

switches to a communication mode in which the radio communication device subject to switching is set to operate as master terminal.

2. A radio communication device which operates as master terminal to form a network with another radio communication devices using a short range radio communication function, comprising:

a positional relationship measuring unit that measures positional relationship between the radio communication device operating as master terminal and the another radio communication devices operating as slave terminals;

a switch timing judgment unit that judges timing of a switch in communication mode using the positional relationship;

a positional relationship information processing unit that requests the another radio communication devices to notify positional relationship information indicating the positional relationship between the another radio communication devices and each of the terminals forming the network, and receives the positional relationship information notified by the another radio communication devices;

a remaining battery power measuring unit that measures the remaining battery power of the master terminal;

a battery information processing unit that requests the another radio communication devices to notify battery information indicating the remaining battery power thereof, and receives the battery information notified by the radio communication devices;

a switch timing judgment unit that judges the timing of a switch in communication mode using the positional relationship and the battery information;

a switching subject terminal determining unit that selects a radio communication device subject to switching using the positional relationship information and the battery information; and

a communication mode switching processing unit that switches to a communication mode in which the radio communication device subject to switching is set to operate as a new master terminal.

8. The radio communication device according to claim 2, wherein the positional relationship information received by the positional relationship information processing unit includes the number of terminals included within the communication ranges of the radio communication devices which are sources of the notification of the positional relationship information, and

wherein the switching subject terminal determining unit determines as the radio communication device subject to switching a radio communication device with the greatest remaining battery power from among the radio communication devices that include, within the communication ranges thereof, the largest number of the terminals forming the network.

10. The radio communication device according to claim 2, wherein the positional relationship information received by the positional relationship information processing unit includes the number of terminals included within the communication ranges of the radio communication devices which are the sources of the notification of the positional relationship information and information regarding the distances between the notification source radio communication devices and the another terminals included within the communication ranges thereof, and

wherein the switching subject terminal determining unit determines the radio communication device subject to switching on the basis of the number of terminals, the distance information, and the battery information.

3. A radio communication device which operates as slave terminal to form a network with another radio communication devices using a short range radio communication function, comprising:

a positional relationship measuring unit that measures positional relationship between the slave terminal and each of the terminals forming the network;

a positional relationship information processing unit that notifies a radio communication device operating as master terminal of the positional relationship measured by the positional relationship measuring unit; and

a communication mode switching processing unit that switches to a communication mode in which the radio communication device operating as slave terminal becomes master terminal in accordance with an instruction from the radio communication device operating as master terminal.

4. The radio communication device according to claim 3, wherein the positional relationship measuring unit comprises means for measuring as the positional relationship the number of terminals included within the communication range of the radio communication device operating as slave terminal and the distance between the radio communication device operating as slave terminal and the another terminals included within the communication range thereof.

5. The radio communication device according to claim 3, further comprising:

a remaining battery power measuring unit that measures the remaining battery power in the radio communication device operating as slave terminal; and

a battery information processing unit that notifies the radio communication device operating as master terminal of the remaining battery power measured by the remaining battery power measuring unit.

13. The radio communication device according to claim 3, wherein the communication mode switching processing unit switches to a communication mode in which the slave terminal is set to operate as master terminal, upon the disconnection from the network of the radio communication device operating as master terminal.

14. A radio communication device which operates as master terminal or slave terminal in accordance with pre-performed function setting and which is used in a radio communication system that forms a network in which a radio communication device operating as master terminal and a plurality of radio communication devices operating as slave terminals are connected using a short range radio communication function,

the radio communication device comprising when operating as master terminal:

substitute designation information transmission means for transmitting to an arbitrary slave terminal substitute designation information designating to operate as a substitute master terminal; and

configuration information transmission means for transmitting network configuration information regarding a current network to the slave terminal to which the substitute designation information is transmitted, and

the radio communication device comprising when operating as slave terminal;

reception means for receiving the substitute designation information and the network configuration information from the master terminal;

disconnection detection means for detecting disconnection of the master terminal from the network following reception of the substitute designation information and the network configuration information; and

communication mode switching processing means for switching settings from a function setting for operating as slave terminal to a function setting for operating as master terminal when the master terminal is disconnected from the network, and thereby switching to a communication mode in which the slave terminal operates as master terminal.

15. The radio communication device according to claim 14, further comprising, when operating as the master terminal, disconnection detection means for detecting whether or not the slave terminal to which the substitute designation information is transmitted is disconnected,

wherein the substitute designation information transmission means select, if the slave terminal to which the substitute designation information is transmitted is disconnected, an arbitrary slave terminal other than the disconnected slave terminal and transmit the substitute designation information thereto.

16. The radio communication device according to claim 14, further comprising:

a remaining battery power measuring unit that measures remaining battery power of the radio communication device;

a battery information processing unit that, when the radio communication device operates as a master terminal, requests the slave terminals that constitute the network to notify battery information indicating remaining battery power of the slave terminals and receives the battery information notified by the slave terminals, and that, when the radio communication device operates as a slave terminal, transmits to the master terminal battery information indicating a remaining battery power of the slave terminal according to a notification request from the master terminal; and

a substitute terminal determining unit that determines a slave terminal to which the substitute designation information is transmitted based on the battery information.

17. The radio communication device according to claim 14, further comprising:

a remaining memory capacity measuring unit that measures remaining memory capacity of the radio communication device;

a memory information processing unit that, when the radio communication device operates as a master terminal, requests the slave terminals that constitute the network to notify memory information indicating remaining memory capacity of the slave terminals and receives the memory information notified by the slave terminals, and that, when the radio communication terminal operates as a slave terminal, transmits to the master terminal memory information indicating a remaining memory capacity of the slave terminal according to a notification request from the master terminal; and

a substitute terminal determining unit that determines a slave terminal to which the substitute designation information is transmitted based on the memory information.