Method of Handling Random Access Procedure and Related Communication Device

• US 20110014922A1
• Filed: 07/14/2010
• Published: 01/20/2011
• Est. Priority Date: 07/14/2009
• Status: Active Grant

• Current Assignee: HTC Corporation
• Original Assignee: HTC Corporation
• Inventors: Jen, Yu-Chih
• Granted Patent: US 8,619,649 B2
• Time in Patent Office: Days
• US Class Current: 455/450
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 74/002 Transmission of channel access control information
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 84/047 using dedicated repeater stations

Abstract

A method of handling random access procedure for a network in a wireless communications system is disclosed. The method comprises configuring a plurality of access points or a plurality of component carriers with at least one of a plurality of physical random access channel (PRACH) resources, a plurality of preamble formats, and a plurality of preamble sequences, whereby a mobile device of the wireless communication system uses at least one of the plurality of PRACH resources, the plurality of preamble formats, and the plurality of preamble sequences to access at least one of the plurality of access points or the plurality of component carriers when performing at least a random access procedure.

Claims

1. A method of handling random access procedure for a network in a wireless communications system, the method comprising:

configuring a plurality of access points or a plurality of component carriers with at least one of a plurality of physical random access channel (PRACH) resources, a plurality of preamble formats, and a plurality of preamble sequences;

whereby a mobile device of the wireless communication system uses at least one of the plurality of PRACH resources, the plurality of preamble formats, and the plurality of preamble sequences to access at least one of the plurality of access points or the plurality of component carriers when performing at least a random access procedure.

2. The method of claim 1, wherein the plurality of access points includes at least one of at least a base station and at least a relay of the network;

or the plurality of access points are operated at the same component carrier or different component carriers;

or a number of the plurality of access points is two or more than two.

3. The method of claim 1, wherein the network includes at least one of at least a base station and at least a relay to configure the plurality of access points or the plurality of component carriers with at least one of the plurality of PRACH resources, the plurality of preamble formats, and the plurality of preamble sequences for at least one accessing mobile device.

4. The method of claim 1, further comprising:

after the mobile device accesses on at least one of the plurality of PRACH resources with at least a preamble transmission, utilizing at least one of the plurality of access points which receive the at least a preamble, to determining determine which access points or component carriers the mobile device accesses to according to the reception of the at least a preambles from the mobile device;

or

after the mobile device accesses on at least one of the plurality of PRACH resources with at least a preamble transmission, utilizing at least one of the plurality of access points which receive the at least a preamble, to responding to the mobile device at least a random access response (RAR) message addressed by at least a random access radio network temporary identifier (RA-RNTI) associated with the at least one of the accessed PRACH resources.

5. The method of claim 4, wherein after the mobile device accesses on at least one of the plurality of PRACH resources with at least a preamble transmission, utilizing at least one of the plurality of access points which receive the at least a preamble, to determining determine which access points or component carriers the mobile device accesses to according to the reception of the at least a preambles from the mobile device comprises:

determining which access points or component carriers the mobile device accesses to according to at least one of the accessed PRACH resources, used preamble formats, and used preamble sequences;

or further comprising;

determines which access points or component carriers the mobile device accesses to according to at least one of uplink transmission resources that the mobile device accesses to, a temporary cell radio network temporary identifiers (T-CRNTIs) used by the mobile device, a modulation and coding schemes (MCSs) used by the mobile device, a reference signal cyclic shift values used by the mobile device, and an indications for a uplink transmission when receiving the uplink transmissions;

or

further comprising;

responding to the mobile device a downlink message indicating allowed access points or component carriers for the mobile device to access.

6. The method of claim 5, wherein the allowed access points or component carriers are decided by the network according to at least one of a mobile device capability, traffic load, measurement, power control, interference control, and a predefined rule.

7. The method of claim 3, wherein configuring the plurality of access points or the plurality of component carriers with the plurality of PRACH resources, the plurality of preamble formats, and the plurality of preamble sequences comprises:

configuring the plurality of access points or the plurality of component carriers with the plurality of PRACH resources, the plurality of preamble formats, and the plurality of preamble sequences broadcasted in system information or in a control signaling from the network.

8. The method of claim 2, wherein the relay is non-transparent to the mobile device;

or the relay has a relay indication or a relay identity, but has no separated cell identity for coverage of the relay.

9. The method of claim 4, wherein after the mobile device accesses on at least one of the plurality of PRACH resources with at least a preamble transmission, controlling at least one of the plurality of access points which receive the at least a preamble, to responding to the mobile device at least a RAR message addressed by at least a RA-RNTI associated with at least one of the accessed PRACH resources comprises:

utilizing at least one of the plurality of access points to responding to the mobile device with at least a RAR message addressed by at least a RA-RNTI according to at least one of measurement, reception, preamble detection, power control, interference control, or traffic load;

or

utilizing at least an access point to respond to the mobile device at least a RAR message addressed by at least a RA-RNTI associated with at least one of the accessed PRACH resources.

10. The method of claim 4, wherein the RAR message from each of the access points is addressed by a RA-RNTI associated with each of the access points respectively;

or the RAR message from each of the access points is addressed by the same RA-RNTI;

or the RAR message from each of access points is received by the mobile device on different physical down link control channels (PDCCHs) associated with the access points respectively, or on the same PDCCH.

11. The method of claim 9, wherein the at least a RAR message for the mobile device includes at least one temporary cell radio network temporary identifiers (T-CRNTIs) or at least one an uplink grant associated with at least one of access points, or is received by the mobile device in a subframe;

or

wherein the RAR messages for the mobile device include different temporary cell radio network temporary identifiers (T-CRNTIs) or uplink grants associated with at least one of different access points and different component carriers accessed by the mobile device, or are received by the mobile device in different subframes;

or

wherein the RAR message for the mobile device from each of the access points includes distinct temporary cell radio network temporary identifier (T-CRNTI) or an distinct uplink grant associated with the each access point, or is received by the mobile device in a distinct subframe;

or

wherein only one of the at least a RAR message includes temporary cell radio network temporary identifier (T-CRNTIs) or an uplink grant associated with a access point, or is received by the mobile device in a distinct subframe.

12. The method of claim 9, wherein the RAR message is determined by the network or the at least one access point according to a traffic load, a measurement, or a predefined rule.

13. A method of handling random access procedure for a mobile device in a wireless communications system, the method comprising:

performing a random access procedure to access a network of the wireless communication system; and

determining at least one of a physical random access channel (PRACH) resource, a preamble format and a preamble sequence for the random access procedure according to the nearest PRACH opportunity, according to a selection rule, or according to a measurement or an indication from network.

14. The method of claim 13, further comprising:

receiving at least a random access response (RAR) message from the network; and

transmitting at least an uplink transmission to the network according to the received RAR messages.

15. The method of claim 14, wherein transmitting at least an uplink transmission to the network according to the received RAR messages comprising:

transmitting at least an uplink transmission with a modulation and coding schemes (MCS), a reference signal cyclic shift value, or an indication according to the received RAR messages.

16. The method of claim 15, wherein the at least UL transmission further includes a message of a RRC layer or a MAC layer.

17. The method of claim 13, further comprising:

deciding to perform the at least an uplink transmission according to at least one of a measurement, cell selection preference, service, power control, interference control, positioning, received RAR, mobile device capability, indication from network, and hearability.

18. A method of handling random access procedure for a network in a wireless communications system, the method comprising:

configuring a plurality of access points or a plurality of component carriers with different sets of power control parameters for physical random access channel (PRACH) access, different PRACH resources and associated random access radio network temporary identifiers (RA-RNTIs), different physical down link control channels (PDCCHs), different sets of temporary cell radio network temporary identifiers (T-CRNTIs), different back-off control parameters, different random access response (RAR) window length, and different contention resolution timer length, whereby a mobile device decides at least one of at least an access point and at least a component carrier to perform at least one random access procedure, and uses the at least one configuration associated with the at least one of at least an access point and at least a component carrier during the at least one random access procedure.

19. The method of claim 18, wherein configuring the plurality of access points or the plurality of component carriers with different sets of power control parameters for PRACH access, different PRACH resources and associated RA-RNTIs, different PDCCHs, different sets of T-CRNTIs, different back-off control parameters, different RAR window length, and different contention resolution timer length comprises:

configuring the plurality of access points or the plurality of component carriers with different sets of power control parameters for PRACH access, different PRACH resources and associated RA-RNTIs, different PDCCHs, different sets of T-CRNTIs, different back-off control parameters, different RAR window length, and different contention resolution timer length based on at least one of traffic load, processing capability, resource scheduling, antenna capability, power control, interference control, deployment scenario, control resource availability, RNTI availability, and measurement;

or

configuring the plurality of access points or the plurality of component carriers with different sets of power control parameters for PRACH access, different PRACH resources and associated RA-RNTIs, different PDCCHs, different sets of T-CRNTIs, different back-off control parameters, different RAR window length, and different contention resolution timer length broadcasted in system information or in a control signaling from the network.

20. The method of claim 18, wherein the different Back-off control parameters are configured for different downlink component carriers or access points;

or the different Back-off control parameters are configured for different downlink component carriers or access points for load balancing at camping or collision alleviation.

21. A method of handling random access procedure for a mobile device in a wireless communications system, the method comprising:

performing at least a random access procedure to access at least an access point or component carrier; and

deciding which component carriers or access points to camp on according to service requirements or service priorities of the mobile device.

22. A method of handling random access procedure for a network in a wireless communications system, the method comprising:

configuring different service requirements or a service priorities to different component carriers or access points.

23. A method of handling random access procedure for a mobile device in a wireless communications system, the method comprising:

performing at least a random access procedure to access at least an access point or component carrier with at least a preamble;

receiving from the at least an access points or the component carrier at least a random access response (RAR) message addressed by at least a random access radio network temporary identifiers (RA-RNTIs) associated with at least a physical random access channel (PRACH) access or configuration, where the RAR messages include at least one of duplicated temporary cell radio network temporary identifiers (T-CRNTIs) and uplink grants for the preambles, or each of RAR messages includes at least one of duplicated T-CRNTIs and UL grants for the preambles, or the RAR messages include the preambles associated with at least one of duplicated T-CRNTIs and UL grants.

24. The method of claim 23, wherein the RAR messages further include duplication indications for indicating the duplicated T-CNRITs or uplink grants.

25. The method of claim 23, further comprising:

including an indication of the access point or component carrier which the mobile device wants or supports to camp on in an uplink transmission of the random access procedure so that the access point assigns a new cell radio network temporary identifier (C-RNTI) in a contention resolution message of the random access procedure after receiving the uplink transmission;

or

including the preamble used for accessing the access point or component carrier in the uplink transmission,

whereby the access point assigns a new cell radio network temporary identifier (C-RNTI) in a contention resolution message of the random access procedure after receiving the uplink transmission so that the access point assigns the new C-RNTI in the contention resolution message of the random access procedure after receiving the uplink transmission.

26. A method of handling random access procedure for a network in a wireless communications system, the method comprising:

configuring a plurality of access points or component carriers with the same physical random access channel (PRACH) configuration, whereby a mobile device of the wireless communication system performs at least a random access procedure to access PRACH with at least a preamble.

27. The method of claim 26, wherein some of the plurality of access points or component carriers transmit at least a random access response (RAR) message to the mobile device when receiving the preambles from the mobile device.

28. A method of handling random access procedure for a mobile device in a wireless communications system, the method comprising:

performing at least a random access procedure to access at least an access point or component carrier; and

determining which access point or component carrier transmits a random access response (RAR) message according to a RA-RNTI detected in the RAR message, a T-CRNTI allocated in the RAR message, or an uplink grant in the RAR message.

29. A method of handling random access procedure for a mobile device in a wireless communications system, the method comprising:

performing a random access procedure to a network of the wireless communication system; and

waiting for a contention resolution message of the random access procedure until expiry of a contention resolution related timer or stop of the contention resolution related timer, or as long as the mobile device does not detect that the mobile devices wins a contention associated with the random access procedure before the expiry of the contention resolution related timer or a re-contention wait timer.

30. The method of claim 29, further comprising:

continuing to monitor a PDCCH and wait for the contention resolution message when the mobile device has detected the PDCCH addressed by a T-CRNTI adopted by the mobile device before the expiry of the contention resolution related timer, but fails at detecting contention resolution identity of the mobile device in the contention resolution message, or the mobile device has a C-RNTI.

31. The method of claim 29, wherein the re-contention wait timer is indicated or preconfigured to the mobile device to indicate how long the mobile device shall wait after the mobile device detects that the mobile device loses the contention or after the expiry of contention resolution timer.

32. The method of claim 30, wherein the contention resolution message includes a new assigned RNTI to the mobile device as the C-RNTI.

33. A method of handling random access procedure for a network in a wireless communications system, the method comprising:

receiving a first uplink transmission of a first random access procedure from a first mobile device of the wireless communication system and a second uplink transmission of a second random access procedure from a second mobile device of the wireless communication system; and

responding to the first mobile device with a first contention resolution message and then responding to the second mobile device with a second contention resolution message before a contention resolution timer at the first mobile device or at the second mobile device expires, where the first and the second mobile device share the same time-frequency resource for the first and second uplink transmissions, or the first and the second UE use different time-frequency resources for the first and second uplink transmissions;

or

responding to the first mobile device with a first contention resolution message and then responding to the second mobile device with a second contention resolution message before a re-contention wait timer at the first mobile device or at the second mobile device expires, where the first and the second mobile device share the same time-frequency resource for the first and second uplink transmissions, or the first and the second UE use different time-frequency resources for the first and second uplink transmissions;

or

responding to the first mobile device and the second mobile device in the same contention resolution message.

34. The method of claim 33, wherein the first mobile device and the second mobile device share the same T-CRNTI, or use the same PRACH resource and preamble for the first and second random access procedure, or access PRACH on different areas of network coverage.

35. The method of claim 33, wherein the contention resolution message includes coverage identification for the first mobile device and the second mobile device, or includes a new assigned RNTI to the first mobile device or the second mobile device.

36. The method of claim 33, wherein the first mobile device recognizes a first contention resolution content of the first mobile device in the contention resolution message, and the second mobile device recognizes a second contention resolution content of the second mobile device in the contention resolution message.

37. A method of handling random access procedure for a mobile device in a wireless communications system, the method comprising:

initiating a random access (RA) procedure; and

prioritizing a transmission or reception related to the RA procedure at at least a subframe when each of the at least a subframe is configured for a first purpose other than a RA purpose or when the mobile device is allocated with a uplink grant at the at least a subframe.

38. The method of claim 37, wherein the transmission related to the RA procedure is a RA preamble transmission or a message 3 uplink transmission;

or the reception related to the RA procedure is a random access response reception or a contention resolution message reception;

or the first purpose is associated with a preconfigured or dynamically-configured transmission by a base station or a relay;

or each of the at least a subframe is a subframe at which the mobile device has to perform a first uplink transmission and the relay has to perform a second uplink transmission;

or each of the at least a subframe is a subframe at which the mobile device has to perform a first downlink reception and the relay has to perform a second downlink reception.

39. The method of claim 37, wherein the mobile device is under coverage of a relay performing the RA procedure with the mobile device;

or the relay is transparent or non-transparent to the mobile device;

or the relay has a separated cell identity corresponding to coverage of the relay or uses the same cell identity as a cell of a donor base station of the mobile device.

40. The method of claim 37, wherein prioritizing the transmission or reception related to the RA procedure at the at least a subframe when each of the at least a subframe is configured for the first purpose other than the RA purpose or the mobile device is allocated with the uplink grant at the at least a subframe comprises:

monitoring a downlink channel for a random access response (RAR) reception during or at the at least a subframe when a window for the RAR reception does not expire or does not stop;

or

monitoring a downlink channel for reception of a contention resolution message during or at the at least a subframe when a timer for providing validity of period of receiving the contention resolution message does not expire or does not stop;

or

further comprising;

not expecting a downlink transmission related to the RA procedure when no RA procedure is ongoing or when the RA procedure has been finished.

41. The method of claim 37, wherein each of the at least a subframe is a multi-media broadcast over a single frequency network (MBSFN) subframe or a blank subframe when the first purpose is in-band relaying operation purpose, and prioritizing the transmission or reception related to the RA procedure at the at least a subframe when each of the at least a subframe is configured for the first purpose other than the RA purpose or the mobile device is allocated with the uplink grant at the at least a subframe comprises:

monitoring a downlink channel for a random access response (RAR) reception at the at least a MBSFN or blank subframe when a window for the RAR reception does not expire or does not stop;

or

monitoring a downlink channel for reception of a contention resolution message during or at the at least a MBSFN or blank subframe when a timer for providing validity of period of receiving the contention resolution message does not expire or does not stop.

42. The method of claim 40, further comprising:

not expecting a downlink transmission related to the RA procedure when no RA procedure is ongoing or when the RA procedure has been finished.

43. The method of claim 41 further comprising:

stopping waiting for a RAR reception prior to expiry of the window when the rest time of the window is overlapped with the at least a subframe;

or skipping monitoring the RAR reception during the at least a subframe;

or terminating or stopping the window when the mobile device stops waiting for the RAR;

or

further comprising;

stopping waiting for a contention resolution message reception prior to the expiry of a timer when the rest time of the timer is overlapped with the at least a subframe, wherein the timer provides validity of period of receiving the contention resolution message;

or

skipping monitoring the contention resolution message reception prior to the expiry of the timer during the at least a subframe or

terminating or stopping the timer when the mobile device stops waiting for the contention resolution message.

44. A method of handling random access procedure for a network in a wireless communications system, the method comprising:

transmitting to a mobile device a first downlink transmission related to a random access (RA) procedure of the mobile device or expecting a first uplink transmission from the mobile device related to the RA procedure during at least a first subframe, when the mobile device has been configured with the at least a first subframe for a first purpose other than a RA purpose or has been allocated with an uplink grant for the at least a first subframe.

45. The method of claim 44 further comprising:

prioritizing a transmission or reception related to the RA procedure of the mobile device during the at least a first subframe;

or

further comprising;

controlling a base station to perform a second downlink transmission to a relay during the at least a first subframe;

or

controlling the relay to perform a second uplink transmission to the base station during the at least a first subframe;

or

further comprising;

allocating the uplink grant for reception of the first uplink transmission from the mobile device during the at least a first subframe;

or

signaling a feedback associated with the first uplink transmission to the mobile device during at least a second subframe, wherein the mobile device has been configured with the at least a second subframe for a second purpose other than a RA purpose or has been allocated with an uplink grant for the at least a second subframe.

46. A method of handling random access procedure for a network in a wireless communications system, the method comprising:

not transmitting a downlink transmission, a random access response (RAR) or a contention resolution message of a random access (RA) procedure to a mobile device during at least a first subframe when a transmission opportunity collision associated with the at least a first subframe occurs;

or

not scheduling uplink transmission or uplink transmission of the RA procedure to the mobile device during at least a second subframe.

47. The method of claim 46, wherein the network shall not transmit the downlink transmission or the RAR or the contention resolution message to the mobile device at the at least a first subframe when the at least a first subframe has been configured to the mobile device for a first purpose other than a RA purpose;

or the network shall not schedule uplink transmission of the mobile device when the at least a second subframe has been scheduled for UL transmission of a relay;

or the network shall not transmitted RAR at a third subframe corresponds to an uplink transmission of RA procedure at a fourth subframe colliding with the at least a second subframe;

or the mobile device indicates at least a fifth subframe for the uplink transmission colliding with the second subframe.

48. The method of claim 46, wherein the mobile device is under coverage of a relay performing the RA procedure with the mobile device;

or the relay is transparent or non-transparent to the mobile device;

or the relay has a separated cell identity corresponding to coverage of the relay or uses the same cell identity as a cell of a donor base station of the mobile device.

49. The method of claim 46, wherein the at least a first subframe is a multi-media broadcast over a single frequency network (MBSFN) subframe or a blank subframe when the first purpose is in-band relaying operation purpose;

or the at least a second subframe is used for an uplink transmission from a relay to a base station;

or the at least a second subframe is indicated to the mobile device that the at least a second subframe is used for the uplink transmission from the relay to the base station;

or the at least a first subframe is used for a purpose other than the RAR transmission purpose;

or the at least a first subframe is used or configured for a purpose other than the downlink transmission purpose for the mobile device;

or the at least a second subframe is used or configured for a purpose other than the uplink transmission purpose for the mobile device.

50. The method of claim 47, wherein the RAR includes a field that indicates the fourth subframe;

or a reception subframe of the RAR corresponds to or results in the fourth subframe.

51. The method of claim 46 further comprising:

allocating to the mobile device a first physical random access channel (PRACH) resource corresponding to a first RA preamble access to a base station; and

allocating to the mobile device a second PRACH resource corresponding to a second RA preamble access to a relay;

whereby the mobile device monitors the RAR addressed by a first random access-radio network temporary identifier (RA-RNTI) corresponding to the first RA preamble access and by a second RA-RNTI corresponding to the second RA preamble access, where the first and second RA-RNTIs implies or indicates a subframe for an uplink transmission of the uplink grant in the RAR.

52. A method of handling random access procedure for a mobile device in a wireless communications system, the method comprising:

receiving at least one of system information and control signaling, wherein the system information or control signaling includes at least one of information about an in-band uplink transmission opportunity corresponding to a relay and information used for prohibiting the in-band uplink transmission opportunity corresponding to the mobile device dynamically or semi-statically.

53. The method of claim 52, wherein the system information or control signaling is received from a base station or a relay.

54. The method of claim 52 further comprising:

not applying an uplink grant for an in-band uplink transmission at the in-band uplink transmission opportunity;

or

applying the uplink grant for the in-band uplink transmission at a first subframe which corresponds to a second subframe later after the in-band uplink transmission opportunity.

55. The method of claim 54, wherein the second subframe is indicated in a random access response (RAR) during performance of a random access procedure of the mobile device;

or the second subframe is indicated in the system information or the control signaling;

the second subframe is indicated according to physical random access channel (PRACH) configuration or a random access-radio network temporary identifier (RA-RNTI) addressing the RAR received by the mobile device;

or the second subframe is a predefined subframe.

56. A method of handling random access procedure for a mobile device in a wireless communications system, the method comprising:

initiating a random access procedure to a network entity;

waiting for a contention resolution message during the random access procedure until expiry or stopping of a timer; and

waiting for the contention resolution message during the random access procedure when the mobile device does not detect that the mobile device is a winner of a contention of the random access procedure before the expiry of the timer or expiry of a re-contention wait timer, wherein the timer provides validity of period of receiving the contention resolution message.

57. The method of claim 56, wherein the network entity is a base station or a relay.

58. The method of claim 57, wherein the relay is non-transparent or transparent to the mobile device;

or the relay has a separated cell identity for coverage of the relay, or uses the same cell identity as a cell of a donor base station of the mobile device.

59. The method of claim 56 further comprising:

continuing monitoring a physical downlink control channel (PDCCH) signaling and waiting for the contention resolution message when the mobile device has detected a PDCCH signaling addressed by a temporary cell radio network temporary identifier (T-CRNTI) of the mobile device before the expiry of the timer which has been initiated upon a transmission of a previous UL transmission of the mobile device, but the mobile device fails in detecting a contention resolution identity of the mobile device its own in the contention resolution message;

or

continuing monitoring a PDCCH signaling and waiting for the contention resolution message when the mobile device has a cell radio network temporary identifier (C-RNTI).

60. The method of claim 56, wherein the re-contention wait timer is indicated or preconfigured to the mobile device to show how long the mobile device shall wait after the mobile device detects that the mobile device itself is loses the contention in the random access procedure.

61. A method of handling random access procedure for a network entity in a wireless communications system, the method comprising:

determining whether a first mobile device can win the next available contention or not, wherein the first mobile device loses a contention of a random access procedure; and

determining whether a second mobile device can win the next available contention (possible at next transmission of contention resolution message) or not, wherein the second mobile device wins the contention and has failed in reception of a message-4 of the random access procedure.

62. The method of claim 61 further comprises:

determining whether the first mobile device can win a re-contention for the next available contention or for a current contention retransmission, no matter whether an acknowledgement (ACK) of a contention resolution message is received or not, around the time instant when the network entity expects the ACK;

or

determining the second mobile device can win a re-contention for the next available contention or for a current contention retransmission, when the network entity does not receive an acknowledgement (ACK) of a contention resolution message from the second mobile device.

63. The method of claim 62, wherein the network entity is a relay or a base station;

or the relay is non-transparent or transparent to the first mobile device or to the second mobile device;

or the relay has a separated cell identity for coverage of the relay;

or the relay uses the same cell identity as a cell of a donor base station of the mobile device uses.

64. A method of handling random access procedure for a network entity in a wireless communications system, the method comprising:

responding a contention resolution message including contention corresponding to a plurality areas of coverage.

65. The method of claim 64, wherein the network entity is a relay or a base station;

or the relay is non-transparent or transparent to the first mobile device or to the second mobile device;

or the relay has a separated cell identity for coverage of the relay;

or the relay uses the same cell identity as a cell of a donor base station of the mobile device uses.

66. A method of handling random access procedure for a mobile device in a wireless communications system, the method comprising:

initiating a random access procedure; and

waiting for a time or a first number of re-contention chance when the mobile device detects that the mobile device is a loser in a contention of the random access procedure.

67. The method of claim 66 further comprising:

detecting whether the mobile device is the loser in the contention, by receiving an indication of the re-contention or by finding addressing control information on a control channel, where no user equipment identity is detected in a message 4 of the random access procedure;

or

wherein the indication is sent in the message 4 or in the addressing control signaling.

68. The method of claim 66 further comprising:

determining the mobile device as a potential winner of a contention of the random access procedure when the mobile device does not receive a message 4 of the random access procedure successfully.

69. The method of claim 68 further comprising:

automatically deciding how long to wait is allowed and how many re-contention chances are allowed.