METHOD FOR RANDOM ACCESS IN WIRELESS COMMUNICATION SYSTEM, WIRELESS COMMUNICATION SYSTEM, WIRELESS TERMINAL, AND BASE STATION UNIT

• US 20100118788A1
• Filed: 01/19/2010
• Published: 05/13/2010
• Est. Priority Date: 08/10/2007
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: OBUCHI, Kazuhisa, KAWASAKI, Yoshihiro, OHTA, Yoshiaki, TAJIMA, Yoshiharu
• Granted Patent: US 8,737,320 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 74/008 with additional processing of random access related information at receiving side
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

In the event of detecting first information used for first random access and second information used for second random access, the second information being received from the base station unit, a wireless terminal selects one between the first information and the second information. Thereby, either one of the random accesses can be selectively performed, efficiently using resources such as signatures used for random access.

Claims

1. A method for random access in a wireless communication system including a base station unit and a wireless terminal, the method comprising:

at the wireless terminal,

detecting first information used for first random access and second information used for second random access, the second information being received from the base station unit; and

selecting one between the first information and the second information.

2. The method for random access according to claim 1, further comprising:

at the wireless terminal,

creating the first information when uplink data destined for the base station unit arrive; and

receiving the second information when downlink data destined for the wireless terminal from the base station unit arrive.

3. The method for random access according to claim 1, further comprising,

at the wireless terminal,

transmitting third information, which is transmitted to the base station unit during random access not selected in the selecting, to the base station unit during or after the completion of random access selected in the selecting.

4. The method for random access according to claim 1, further comprising:

at the wireless terminal,

halting proceeding of the second random access; and

transmitting uplink synchronization request information, as third information, which requests to establish synchronization of uplink communication for receiving downlink data, to the base station unit during the first random access.

5. The method for random access according to claim 1, further comprising:

at the wireless terminal,

halting proceeding of the first random access; and

transmitting uplink data transmission request information, as third information, which requests to transmit uplink data, to the base station unit during or after the completion of the second random access.

6. The method for random access according to claim 4, wherein the uplink synchronization request information is provided to an uplink message that is to be transmitted to the base station unit during the first random access.

7. The method for random access according to claim 5, wherein the uplink data transmission request information is provided to an uplink message that is to be transmitted to the base station unit during the second random access.

8. The method for random access according to claim 3, further comprising:

at the base station unit,

upon receipt of the third information after detecting the presence of the first information received from the wireless terminal and the second information that the base station unit allocates to the wireless terminal; and

releasing management of the first information or the second information.

9. A method for random access in a wireless communication system including a base station unit and a wireless terminal, the method comprising:

at the wireless terminal,

receiving second information used for second random access in response to generation of downlink data from the base station unit before creating first information used for first random access in response to generation of uplink data destined for the base station unit,

transmitting third information, which is transmitted to the base station unit during the first random access, to the base station unit during or after the completion of the second random access using the second information.

10. A wireless communication system including a base station unit and a wireless terminal, wherein

the wireless terminal selects one from first information used for first random access and second information used for second random access, the second information being received from the base station unit;

and

the base station unit releases management of the information that is not selected between the first information and the second information.

11. A wireless terminal comprising:

creating means that creates first information used for first random access to a base station unit;

receiving means that receives, from the base station unit, second information used for second random access to the base station unit; and

selecting means that selects one between the first information and the second information.

12. The wireless terminal according to claim 11, further comprising:

transmitting means that continues random access corresponding to the information selected by the selecting means and that transmits third information, which is transmitted to the base station unit during random access not selected by the selecting means, to the base station unit.

13. The wireless terminal according to claim 12, wherein

the selecting means selects the first information;

and

the transmitting means transmits uplink synchronization request information, as the third information, which requests to establish synchronization of uplink communication for receiving downlink data, to the base station unit during the first random access.

14. The wireless terminal according to claim 12, wherein

the selecting means selects the second information;

and

the transmitting means transmits uplink data transmission request information, as the third information, which requests to transmit uplink data, to the base station unit during the second random access.

15. The wireless terminal according to claim 13, wherein

the transmitting means provides the uplink synchronization request information to an uplink message that is to be transmitted to the base station unit during the first random access.

16. The wireless terminal according to claim 14, wherein

the transmitting means provides the uplink data transmission request information to an uplink message that is to be transmitted to the base station unit during the second random access.

17. A base station unit comprising:

managing means that manages first information used for first random access received from a wireless terminal and second information used for second random access transmitted to the wireless terminal;

determining means that determines, based on third information received from the wireless terminal, one selected by the wireless terminal between the first information and the second information; and

controlling means that continuing random access corresponding to the information that the determining means determines that the wireless terminal selects and that carries out control based on the third information.

18. The base station unit according to claim 17, wherein

when the third information is uplink synchronization information, which requests to establish synchronization of unlink communication for receiving downlink data, the determining means determines that the first information is selected by the wireless terminal.

19. The base station unit according to claim 17, wherein

when the third information is uplink data transmission request information, which requests to transmit uplink data, the determining means determines that the first (sic, correctly second) information is selected by the wireless terminal.

20. The base station unit according to claim 17, wherein

the control means releases management of information, by the managing means, that the determining means determines not to be selected.