Method and apparatus for detecting contention during random access procedure in a mobile communication system

• US 8,228,827 B2
• Filed: 02/08/2008
• Issued: 07/24/2012
• Est. Priority Date: 02/09/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Jeong, Kyeong-In, Van Lieshout, Gert Jan, Van Der Velde, Himke, Kim, Soeng-Hun
• Primary Examiner(s): Sheikh, Ayaz
• Assistant Examiner(s): Sloms, Nicholas
• Application Number:
  US12/028,508
• Publication Number:
  US 20080194243A1
• Time in Patent Office: 1,628 Days
• Field of Search: None
• US Class Current: 370/278
• CPC Class Codes: H04W 74/0841 with collision treatment
• CPC Class Codes: H04W 74/0866 using a dedicated channel for access

Abstract

A method and apparatus for detecting contention in an RA procedure in a mobile communication system is provided in which an L2/L3 message is received from a UE in uplink resources allocated to the UE by an RA preamble response message that was transmitted for an RA procedure initiated by the UE, a CR message associated the RA procedure is transmitted to the UE, if the L2/L3 message is an initial access message, and predetermined control information is transmitted to the UE on a downlink control channel without transmitting the CR message, if the L2/L3 message is not an initial access message.

Claims

1. A method for performing a random access procedure in a mobile communication system, the method comprising:

receiving a first message including a random access preamble;

transmitting a second message, which is a random access response message, in response to the first message;

determining whether or not a third message including a Cell-Radio Network Temporary Identifier (C-RNTI) is received from a User Equipment (UE);

transmitting a fourth message, which is a Contention Resolution (CR) message for the random access procedure, to the UE, upon receipt of the third message that does not include the C-RNTI from the UE; and

transmitting UE-specific control information to the UE, upon receipt of the third message including the C-RNTI from the UE,

wherein the UE-specific control information includes a Cyclic Redundancy Check (CRC) specifically mapped to the C-RNTI of the UE, and

wherein the first, second, third, and fourth messages occur in a random access procedure in a mobile communication system.

2. The method of claim 1, wherein the UE-specific control information is addressed by the C-RNTI.

3. The method of claim 1, wherein transmitting the UE-specific control information is performed before expiration of a timer activated for collision detection by the UE in the random access procedure.

4. The method of claim 1, wherein transmitting the UE-specific control information is performed on a downlink control channel.

5. An apparatus for performing a random access procedure in a mobile communication system, the apparatus comprising:

a transceiver for transmitting and receiving messages to and from a User Equipment (UE); and

a controller for controlling the transceiver to transmit a random access response message in response to receiving a message including a random access preamble, determining whether or not a message including a Cell-Radio Network Temporary Identifier (C-RNTI) is received from the UE, and controlling the transceiver to transmit a Contention Resolution (CR) message for the random access procedure to the UE, upon receipt of a message that does not include the C-RNTI from the UE, and to transmit UE-specific control information to the UE, upon receipt of the message including the C-RNTI from the UE,

wherein the UE-specific control information includes a Cyclic Redundancy Check (CRC) specifically mapped to the C-RNTI of the UE, and

wherein each of the messages occurs in a random access procedure in a mobile communication system.

6. The apparatus of claim 5, wherein the UE-specific control information is addressed by the C-RNTI.

7. The apparatus of claim 5, wherein the controller controls the transceiver to transmit the UE-specific control information before expiration of a timer activated for collision detection by the UE in the random access procedure.

8. The apparatus of claim 5, wherein transceiver transmits the UE-specific control information on a downlink control channel.

9. A method for performing a random access procedure in a mobile communication system, the method comprising:

receiving a first message, which is a random access response message from a Base Station (BS);

transmitting a second message including a Cell-Radio Network Temporary Identifier (C-RNTI) to the BS, if the C-RNTI exists;

activating a timer for collision detection in the random access procedure, when the message including the C-RNTI is transmitted;

determining that a contention for the random access procedure is resolved successfully, when User Equipment (UE)-specific control information addressable by the C-RNTI is received from the BS before expiration of the time; and

determining that the contention for the random access procedure is not resolved successfully, if the UE-specific control information is not received from the BS before the expiration of the timer,

wherein the UE-specific control information includes a Cyclic Redundancy Check (CRC) specifically mapped to the C-RNTI of the UE,

wherein each of the messages occurs in a random access procedure in a mobile communication system.

10. The method of claim 9, further comprising;

transmitting a message that does not include the C-RNTI to the BS, if the C-RNTI does not exist;

determining if the contention for the random access procedure is resolved successfully, when a Contention Resolution (CR) message for the random access procedure is received from the BS.

11. The method of claim 9, wherein the UE-specific control information is received on a downlink control channel.

12. A User Equipment (UE) for a mobile communication system, comprising:

a transceiver for transmitting and receiving messages to and from a Base Station (BS); and

a controller for controlling the transceiver to transmit a message including a Cell-Network Temporary Identifier (C-RNTI) to the BS, if the C-RNTI exists, upon receipt of a random access response message from the BS and activating a timer for collision detection in a random access procedure,

determining that a contention for the random access procedure is resolved successfully, when User Equipment (UE)-specific control information addressable by the C-RNTI is received from the BS before expiration of the time; and

determining that the contention for the random access procedure is not resolved successfully, if the UE-specific control information is not received from the BS before the expiration of the timer,

wherein the UE-specific control information includes a Cyclic Redundancy Check (CRC) specifically mapped to the C-RNTI of the UE,

wherein each of the messages occurs in a random access procedure in a mobile communication system.

13. The UE of claim 12, wherein the controller controls the transceiver to transmit a message that does not include the C-RNTI to the BS, if the C-RNTI does not exist, and to determine if the contention for the random access procedure is resolved successfully, when a Contention Resolution (CR) message for the random access procedure is received from the BS.

14. The UE of claim 12, wherein the UE-specific control information is received on a downlink control channel.