RADIO COMMUNICATION SYSTEM, RADIO TERMINAL, RADIO STATION, AND CELL SELECTION METHOD

• US 20150156690A1
• Filed: 07/04/2013
• Published: 06/04/2015
• Est. Priority Date: 07/05/2012
• Status: Active Application

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Futaki, Hisashi
• Granted Patent: US 10,257,756 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 48/20 Selecting an access point

Abstract

The present invention is a radio communication system in which a radio station and a radio terminal communicate with each other. The radio communication system has a control means with which at least one of the radio stations controls a plurality of types of cells by using one radio access technology, a recognition means with which the radio terminal recognizes the types of the cells, and a cell selection means with which the radio terminal selects the cell based on cell selection criteria based on the types of the cells.

Claims

1. A radio communication system in which a radio station and a radio terminal communicate with each other, comprising:

a control unit with which at least one of the radio stations controls a plurality of types of cells by using one radio access technology;

a recognition unit with which the radio terminal recognizes a type of a cell; and

a cell selection unit with which the radio terminal selects the cell based on cell selection criteria according to the type of the cell.

3. The radio communication system according to claim 1, wherein

the type of the cell is identified by a type of a carrier being a component of the cell.

2. (canceled)

4-14. -14. (canceled)

15. A radio terminal for use in a radio communication system in which a radio station controls a plurality of types of cells by using one radio access technology, comprising:

a recognition unit that recognizes a type of a cell; and

a cell selection unit that selects the cell based on a cell selection criteria according to the type of the cell.

16. The radio terminal according to claim 15, wherein

a selection of the cell is a cell selection or a cell reselection in a state in which a radio connection between the radio terminal and the radio station is not established.

17. The radio terminal according to claim 15, wherein

the type of the cell is identified by a type of a carrier being a component of the cell.

18. The radio terminal according to claim 17, wherein

the type of the carrier is classified by a transmission configuration of a transmitted signal.

19. The radio terminal according to claim 17, wherein

the type of the carrier is classified by a configuration of a physical channel.

20. The radio terminal according to claim 17, wherein

the type of the carrier is classified by the transmission configuration of at least any one of a known signal, system information, and a control signal transmitted from the radio station in the carrier.

21. The radio terminal according to claim 17, wherein

the type of the carrier is classified by contents of the system information.

26. The radio terminal according to claim 15, wherein

the cell selection criteria are received from the radio station.

27. The radio terminal according to claim 15, wherein

the radio terminal is classified into a radio terminal having a function to use only a first carrier and a radio terminal having a function to use the first carrier and a second carrier.

28. The radio terminal according to claim 27, wherein

a function to use the first carrier and the second carrier is equipped, and

in a frequency band supported by the radio terminal, the cell selection unit preferentially selects a cell of the second carrier that satisfies the cell selection criteria.

22-25. -25. (canceled)

29. A radio station comprising:

a control unit that controls a plurality of types of cells by using one radio access technology; and

a unit that broadcasts or individually transmits cell selection criteria to be criteria when a radio terminal selects the cell, wherein

the cell selection criteria are configured in accordance with a type of a cell.

30. A cell selection method comprising:

causing at least one radio station to control a plurality of types of cells by using one radio access technology;

causing a radio terminal to recognize a type of a cell; and

causing the radio terminal to select the cell based on a cell selection criteria according to the type of the cell.

31. The cell selection method according to claim 30, wherein

a selection of the cell is a cell selection or a cell reselection in a state in which a radio connection between the radio terminal and the radio station is not established.

32. The cell selection method according to claim 30, wherein

the type of the cell is identified by a type of a carrier being a component of the cell.

33. The cell selection method according to claim 32, wherein

the type of the carrier is classified by a transmission configuration of a transmitted signal.

34. The cell selection method according to claim 32, wherein

the type of the carrier is classified by a configuration of a physical channel.

42. The cell selection method according to claim 30, wherein

the radio station controls at least a first carrier and a second carrier, and

the radio terminal is classified into a first radio terminal having a function to use only the first carrier and a second radio terminal having a function to use the first carrier and the second carrier.

43. The cell selection method according to claim 42, wherein

in a frequency band supported by the second radio terminal, the second radio terminal preferentially selects a cell of the second carrier that satisfies the cell selection criteria.

35-41. -41. (canceled)