Preamble retransmission method in mobile communications system

• US 8,085,738 B2
• Filed: 02/05/2007
• Issued: 12/27/2011
• Est. Priority Date: 02/07/2006
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Park, Sung-Jun, Lee, Young-Dae, Chun, Sung-Duck, Jung, Myung-Cheul
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): Boakye, Alexander
• Application Number:
  US12/278,555
• Publication Number:
  US 20090257407A1
• Time in Patent Office: 1,786 Days
• Field of Search: 370/336, 370/331, 370/337, 370/338, 370/329, 370/341, 370/342, 370/345, 370/347, 370/349, 370/350, 370/312, 370/321, 370/322, 370/324, 370/277
• US Class Current: 370/336
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 74/02 Hybrid access
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 74/0866 using a dedicated channel for access
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A preamble retransmission method in an Evolved Mobile Telecommunications System (E-UMTS) system is provided by which a terminal transmits a Radio Access Channel (RACH) preamble to a base station, the base station compares the received RACH preamble with preset specific criteria and requests retransmission for the RACH preamble to the terminal according to the comparison in order to reduce the probability of data transmission failure due to inaccuracy of time synchronization and to decrease interference with transmissions by other terminals.

Claims

1. A method for scheduling radio resources in a mobile communication system, the method comprising:

transmitting a transport channel preamble;

receiving a response to the transport channel preamble, wherein the response is transmitted by a base station after the base station determines that the transport channel preamble satisfies predetermined criteria, and

wherein the response comprises a request to retransmit the transport channel preamble if it is determined that the transport channel preamble does not satisfy the predetermined criteria, and the response comprises an indication of allocated radio resources if it is determined that the transport channel preamble satisfies the predetermined criteria; and

one of retransmitting the transport channel preamble and transmitting information using allocated radio resources, wherein the transport channel preamble is retransmitted if the response comprises the request to retransmit the transport channel preamble and the information is transmitted if the response comprises the indication of allocated radio resources.

2. The method of claim 1, wherein the transport channel is a Random Access Channel (RACH).

3. The method of claim 1, wherein the response to the transport channel preamble is a control signal.

4. The method of claim 1, wherein the transport channel preamble is associated with one of a Radio Resource Control (RRC) connection request, a cell update, handover, a radio resource request and maintenance of time synchronization.

5. The method of claim 1, wherein retransmitting the transport channel preamble comprises using a signature included in the response.

6. The method of claim 1, wherein retransmitting the transport channel preamble comprises including a retransmission indicator in the retransmitted preamble.

7. A method for scheduling radio resources in a mobile communication system, the method comprising:

receiving a transport channel preamble;

determining if the preamble satisfies predetermined criteria; and

transmitting a response to the transport channel preamble,

wherein the response comprises a request to retransmit the transport channel preamble if it is determined that the preamble does not satisfy the predetermined criteria and the response comprises an indication of allocated radio resources if it is determined that the preamble satisfies the predetermined criteria.

8. The method of claim 7, wherein the predetermined criteria comprise at least one of an error rate of time synchronization or a number of times for performing time synchronization.

9. The method of claim 8, wherein the error rate of time synchronization is 80% of perfect synchronization.

10. The method of claim 7, wherein the transport channel is a Random Access Channel (RACH).

11. The method of claim 7, wherein transmitting the response to the transport channel preamble comprises transmitting a control signal.

12. The method of claim 7, wherein the response further comprises a signature for retransmission of the transport channel preamble if it is determined that the preamble does not satisfy the predetermined criteria.

13. The method of claim 7, wherein the transport channel preamble is associated with one of a Radio Resource Control (RRC) connection request, a cell update, handover, a radio resource request and maintenance of time synchronization.

14. The method of claim 7, further comprising receiving a retransmitted transport channel preamble and recognizing one of a signature of the retransmitted transport channel preamble and a retransmission indicator included in the retransmitted transport channel preamble if it is determined that the preamble does not satisfy the predetermined criteria.

15. A method for scheduling radio resources in a mobile communication system, the method comprising:

a mobile communication terminal transmitting a transport channel preamble;

a network determining if the preamble satisfies predetermined criteria;

the network transmitting a response to the transport channel preamble, the response comprising a request to retransmit the transport channel preamble if it is determined that the preamble does not satisfy the predetermined criteria and the response comprising an indication of allocated radio resources if it is determined that the preamble satisfies the predetermined criteria; and

the mobile communication terminal retransmitting the transport channel preamble if the response comprises a request to retransmit the transport channel preamble and transmitting information using allocated radio resources if the response comprises an indication of allocated radio resources.

16. The method of claim 15, wherein the transport channel is a Random Access Channel (RACH).

17. The method of claim 15, wherein the response to the transmission of the transport channel preamble is a control signal.

18. The method of claim 15, wherein the transport channel preamble is associated with one of a Radio Resource Control (RRC) connection request, a cell update, handover, a radio resource request and maintenance of time synchronization.

19. The method of claim 15, wherein the predetermined criteria comprise at least one of an error rate of time synchronization or a number of times for performing time synchronization.

20. The method of claim 19, wherein the error rate of time synchronization is 80% of perfect synchronization.