RADIO TERMINAL, RADIO SYSTEM, AND PROGRAM

• US 20090067345A1
• Filed: 09/05/2008
• Published: 03/12/2009
• Est. Priority Date: 09/07/2007
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Tandai, Tomoya, Sakamoto, Takafumi
• Application Number:
  US12/205,584
• Publication Number:
  US 20090067345A1
• Time in Patent Office: Days
• US Class Current: 370/254
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A radio terminal managing slave terminals and forming a network together with the slave terminals, includes unit receiving, from a slave terminal, one of a secession request packet and a join request packet, first storage unit storing first identifiers of the slave terminals, second storage unit storing second identifiers to be assigned to the slave terminals and reception channels for the slave terminals, unit determining whether the reception channels assigned to the slave terminals are unevenly distributed after the slave terminal secedes from or joins the network, unit reassigning, when the determination unit determines that the reception channels are unevenly distributed, at least one of the first identifiers to at least one of the slave terminals not to unevenly distribute the reception channels and update the first storage unit, and unit transmitting the at least one of the first identifiers to the at least one of the slave terminals.

Claims

1. A radio terminal which manages a plurality of slave terminals and forms a network together with the slave terminals, comprising:

a reception unit configured to receive, from a slave terminal of the slave terminals, one of a secession request packet and a join request packet, the secession request packet representing that the slave terminal is going to secede from the network, the join request packet representing that the slave terminal is going to join the network;

a first storage unit configured to store a plurality of first identifiers of the slave terminals;

a second storage unit configured to store a plurality of second identifiers to be assigned to the slave terminals and a plurality of reception channels for the slave terminals, the second identifiers corresponding to the reception channels;

a determination unit configured to determine whether the reception channels assigned to the slave terminals in the network are unevenly distributed among channels assigned as reception channels after the slave terminal secedes from or joins the network;

an assigning unit configured to, when the determination unit determines that the reception channels are unevenly distributed among the assigned channels, reassign at least one of the first identifiers to at least one of the slave terminals not to unevenly distribute the reception channels between the assigned channels and update the first storage unit; and

a transmission unit configured to transmit the at least one of the first identifiers to the at least one of the slave terminals.

2. The terminal according to claim 1, wherein the reception channels stored in the second storage unit include a first channel used by the radio terminal for transmission and a second channel used by the radio terminal for reception.

3. The terminal according to claim 2, wherein the second storage unit stores the first channel and the second channel corresponding to odd and even of the second identifiers respectively, or the second channel and the first channel corresponding to odd and even of the second identifiers respectively.

4. The terminal according to claim 2, wherein

the determination unit determines whether a first number of slave terminals using the first channel as the reception channel is larger than a second number of slave terminals using the second channel as the reception channel when the slave terminal joins the network, and

the assigning unit assigns a third identifier to the slave terminal so that the slave terminal uses the second channel if the determination unit determines that the first number is larger than the second number, and assigns a fourth identifier to the slave terminal so that the slave terminal uses the first channel if the determination unit determines that the first number is not larger than the second number.

5. The terminal according to claim 2, wherein

the determination unit determines whether a first number of slave terminals using the first channel as the reception channel is larger than a second number of slave terminals using the second channel as the reception channel by not less than a first predetermined number when the slave terminal secedes from the network,

the assigning unit changes a third identifier of a first slave terminal using the first channel as the reception channel to a fourth identifier of a second slave terminal using the second channel as the reception channel if the determination unit determines that the first number is larger than the second number by not less than the first predetermined number,

if the determination unit determines that the first number is not larger than the second number by not less than the first predetermined number, the determination unit determines whether the second number is larger than the first number by not less than a second predetermined number,

the assigning unit changes the fourth identifier to the third identifier if the determination unit determines that the second number is larger than the first number by not less than the second predetermined number, and does not reassign the third identifier and the fourth identifier if the determination unit determines that the second number is not larger than the first number by not less than the second predetermined number, and

the transmission unit transmits the changed identifier to a corresponding slave terminal.

6. The terminal according to claim 1, wherein when the slave terminal joins the network, the assigning unit assigns an identifier to the slave terminal so that the slave terminal uses the reception channel to which a minimum number of slave terminals are assigned.

7. A radio terminal managed by a master terminal, comprising:

a reception unit configured to receive a first identifier transmitted from the master terminal;

a first storage unit configured to store a second identifier of a self radio terminal;

a changing unit configured to change the second identifier to the first identifier;

a second storage unit configured to store a plurality of third identifiers to be assigned to the radio terminal and a plurality of reception channels for radio terminals including the radio terminal, the third identifiers corresponding to the reception channels;

a read unit configured to, in transmitting a first data packet to a destination radio terminal, read out a fourth identifier of the destination radio terminal and acquire a reception channel corresponding to the fourth identifier from the second storage unit; and

a transmission unit configured to transmit the first data packet to the destination radio terminal using the reception channel.

8. The terminal according to claim 7, wherein the reception channels stored in the second storage unit include a first channel used by the master terminal for transmission and a second channel used by the master terminal for reception.

9. The terminal according to claim 8, wherein the second storage unit stores the first channel and the second channel corresponding to odd and even of the first identifiers respectively, or the second channel and the first channel corresponding to odd and even of the first identifiers respectively.

10. The terminal according to claim 7, further comprising:

a reception unit configured to receive a second data packet transmitted from another radio terminal, and

wherein when the second data packet is normally received, the transmission unit transmits, to said another radio terminal, a packet representing the second data packet has normally been received, using a channel used for reception of the second data packet.

11. A radio system including a plurality of slave radio terminals and a master radio terminal which manages the slave radio terminals, the radio system forming a network, the system comprising:

the master radio terminal including;

a reception unit configured to receive, from a slave radio terminal of the slave radio terminals, one of a secession request packet and a join request packet, the secession request packet representing that the slave radio terminal is going to secede from the network, the join request packet representing that the slave radio terminal is going to join the network;

a first storage unit configured to store a plurality of first identifiers of the slave radio terminals;

a second storage unit configured to store a plurality of second identifiers to be assigned to the slave radio terminals and a plurality of reception channels for the slave radio terminals, the second identifiers corresponding to the reception channels;

a determination unit configured to determine whether the reception channels assigned to the slave radio terminals in the network are unevenly distributed among channels assigned as reception channels after the slave radio terminal secedes from or joins the network;

an assigning unit configured to, when the determination unit determines that the reception channels are unevenly distributed among the assigned channels, reassign at least one of the first identifiers to at least one of the slave radio terminals not to unevenly distribute the reception channels between the assigned channels and update the first storage unit; and

a transmission unit configured to transmit the at least one of the first identifiers to the at least one of the slave radio terminal, and

each of the slave radio terminals including;

a reception unit configured to receive a third identifier transmitted by the transmission unit;

a third storage unit configured to store a fourth identifier of a self slave radio terminal;

a changing unit configured to change the fourth identifier to the third identifier;

a fourth storage unit configured to store same contents as those stored in the second storage unit;

a read unit configured to, in transmitting a data packet to a destination slave radio terminal, read out a fifth identifier of the destination slave radio terminal and acquire a reception channel corresponding to the fifth identifier from the fourth storage unit; and

a transmission unit configured to transmit the data packet to the destination slave radio terminal using the reception channel.

12. A computer readable medium including computer executable instructions, wherein the instructions, when executed by a processor, cause the processor to perform a method in a radio terminal which manages a plurality of slave terminals and forms a network together with the slave terminals comprising:

receiving, from a slave terminal of the slave terminals, one of a secession request packet and a join request packet, the secession request packet representing that the slave terminal is going to secede from the network, the join request packet representing that the slave terminal is going to join the network;

storing, in a first storage unit, a plurality of first identifiers of the slave terminals;

storing, in a second storage unit, a plurality of second identifiers to be assigned to the slave terminals and a plurality of reception channels for the slave terminals, the second identifiers corresponding to the reception channels;

determining whether the reception channels assigned to the slave terminals in the network are unevenly distributed among channels assigned as reception channels after the slave terminal secedes from or joins the network;

reassigning, when the determination unit determines that the reception channels are unevenly distributed among the assigned channels, at least one of the first identifiers to at least one of the slave terminals not to unevenly distribute the reception channels between the assigned channels;

updating the first storage unit; and

transmitting the at least one of the first identifiers to the at least one of the slave terminals.

13. A computer readable medium including computer executable instructions, wherein the instructions, when executed by a processor, cause the processor to perform a method in a radio terminal managed by a master terminal comprising:

receiving a first identifier transmitted from the master terminal;

storing, in a first storage unit, a second identifier of a self radio terminal;

changing the second identifier to the first identifier;

storing, in a second storage unit, a plurality of third identifiers to be assigned to the radio terminal and a plurality of reception channels for radio terminals including the radio terminal, the third identifiers corresponding to the reception channels;

reading out, in transmitting a first data packet to a destination radio terminal, a fourth identifier of the destination radio terminal and acquire a reception channel corresponding to the fourth identifier from the second storage unit; and

transmitting the first data packet to the destination radio terminal using the reception channel.

14. A computer readable medium including computer executable instructions, wherein the instructions, when executed by a processor, cause the processor to perform a method in a radio system including a plurality of slave radio terminals and a master radio terminal which manages the slave radio terminals where the radio system forming a network comprising:

in the master radio terminal,

receiving, from a slave radio terminal of the slave radio terminals, one of a secession request packet and a join request packet, the secession request packet representing that the slave radio terminal is going to secede from the network, the join request packet representing that the slave radio terminal is going to join the network;

storing, in a first storage unit, a plurality of first identifiers of the slave radio terminals;

storing, in a second storage unit, a plurality of second identifiers to be assigned to the slave radio terminals and a plurality of reception channels for the slave radio terminals, the second identifiers corresponding to the reception channels;

determining whether the reception channels assigned to the slave radio terminals in the network are unevenly distributed among channels assigned as reception channels after the slave radio terminal secedes from or joins the network;

reassigning, when the determination unit determines that the reception channels are unevenly distributed among the assigned channels, at least one of the first identifiers to at least one of the slave radio terminals not to unevenly distribute the reception channels between the assigned channels and update the first storage unit; and

transmitting the at least one of the first identifiers to the at least one of the slave radio terminal, and

in each of the slave radio terminals,

receiving a third identifier transmitted by the master radio terminal;

storing, in a third storage unit, a fourth identifier of a self slave radio terminal;

changing the fourth identifier to the third identifier;

storing, in a fourth storage unit, same contents as those stored in the second storage unit;

reading out, in transmitting a data packet to a destination slave radio terminal, a fifth identifier of the destination slave radio terminal and acquire a reception channel corresponding to the fifth identifier from the fourth storage unit; and

transmitting the data packet to the destination slave radio terminal using the reception channel.