Random access procedure with enhanced coverage

• US 20070206531A1
• Filed: 01/18/2007
• Published: 09/06/2007
• Est. Priority Date: 01/20/2006
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Technologies Oy (Nokia Corporation)
• Inventors: Pajukoski, Kari, Tiirola, Esa, Korhonen, Juha, Vainikka, Markku
• Granted Patent: US 9,301,318 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 56/0085 detecting a given structure in the signal
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• 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 74/0866 using a dedicated channel for access
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support

Abstract

A random access procedure for use by a UE wireless communication terminal in communicating with a base station (or Node-B or eNB) of a radio access network, and in particular a E-UTRA network. A random access preamble is sent by the UE via RACH separate and prior to a random access message burst, which is sent on SCH but not until the UE receives one or more messages indicating an acknowledgment of the preamble and providing an allocation on SCH for use in transmitting the message burst, and also providing a preamble identifier, which the radio access network can then use to request retransmission of the message burst if necessary.

Claims

1. A method for use by a user equipment wireless communication terminal in communicating with a base station of a radio access network of a wireless communication system, comprising:

(a) providing for transmission over a random access channel of the wireless communication system a message burst preamble, and including a signature with the preamble;

(b) receiving from the base station in response one or more messages indicating an acknowledgment of having received the preamble and providing a preamble identifier and a resource allocation of a shared channel; and

(c) providing a message burst for transmission on the shared channel according to the resource allocation, but not until receiving the messages indicating the acknowledgment and providing the resource allocation, and including an address in the message burst for use in identifying the user equipment.

2. The method of claim 1, wherein the resource allocation is provided in a message separate from the message indicating the acknowledgment.

3. The method of claim 1, wherein if the user equipment has a temporary cell specific address then the user equipment uses the temporary cell specific address as the address.

4. The method of claim 1, further comprising:

receiving a request for retransmission from the base station indicating the preamble identifier; and

providing the message burst for retransmission to the base station.

5. The method of claim 4, wherein the request for retransmission is a signal from the base station on a downlink shared control channel indicating an uplink resource allocation and including the preamble identifier.

6. The method of claim 1, further comprising receiving an acknowledgement of the base station having received the message burst, wherein the acknowledgement is a signal from the base station on a downlink shared control channel indicating a downlink resource allocation and including the preamble identifier, and wherein the user equipment is configured to decode the signal and obtain an address indicated by the signal, and then compare the address with the address included by the user equipment in the message burst to determine if the acknowledgement is an acknowledgement of the message burst or instead the acknowledgement of a message burst from another user equipment.

7. The method of claim 1, further comprising:

providing for transmission a portion of the message burst using a first narrow frequency range of the shared channel frequency range; and

providing for transmission another portion of the message burst using a second narrow frequency range of the shared channel frequency range different from the first narrow frequency range.

8. The method of claim 1, further comprising providing the preamble for transmission in part using a first narrow frequency range of the random access channel frequency range and in part using a second narrow frequency range of the random access channel frequency range different from the first.

9. The method of claim 1, further comprising obtaining from the one or more messages indicating the acknowledgement a digest of the signature or a signature number, and determining whether the acknowledgment is an acknowledgement of the preamble sent by the user equipment or an acknowledgment of a message from another user equipment wireless communication device.

10. The method of claim 1, further comprising receiving from the base station a further allocation of the shared channel for uplink of user data in response to the message burst, wherein the allocation is provided with the address provided by the user equipment, and wherein the message burst includes information bits providing information useable by the base station in determining the further allocation to assign to the user.

11. A computer program product comprising a computer readable storage structure embodying computer program code thereon for execution by a computer processor, wherein said computer program code comprises instructions for performing a method according to claim 1.

12. An apparatus for use by a user equipment wireless communication terminal in communicating with a base station of a radio access network of a wireless communication system, comprising means for performing the method of claim 1.

13. An apparatus for use by a user equipment wireless communication terminal in communicating with a base station of a radio access network of a wireless communication system, comprising a processor configured to:

(a) provide for transmission over a random access channel of the wireless communication system a message burst preamble, and including a signature with the preamble;

(b) receive from the base station in response one or more messages indicating an acknowledgment of having received the preamble and providing a preamble identifier and a resource allocation of a shared channel; and

(c) provide a message burst for transmission on the shared channel according to the resource allocation, but not until receiving the messages indicating the acknowledgment and providing the resource allocation, and to include an address in the message burst for use in identifying the user equipment.

14. The apparatus of claim 13, wherein the processor is configured to receive the resource allocation in a message separate from the message indicating the acknowledgment.

15. The apparatus of claim 13, wherein the processor is so configured that if the user equipment has a temporary cell specific address then the user equipment uses the temporary cell specific address as the address.

16. The apparatus of claim 13, wherein the processor is further configured to:

receive a request for retransmission from the base station indicating the preamble identifier; and

provide the message burst for retransmission to the base station.

17. The apparatus of claim 16, wherein the request for retransmission is a signal from the base station on a downlink shared control channel indicating an uplink resource allocation and including the preamble identifier.

18. The apparatus of claim 13, wherein the processor is further configured to receive an acknowledgement of the base station having received the message burst, wherein the acknowledgement is a signal from the base station on a downlink shared control channel indicating a downlink resource allocation and including the preamble identifier, and wherein the processor is configured to decode the signal and obtain an address indicated by the signal, and then compare the address with the address included by the user equipment in the message burst to determine if the acknowledgement is an acknowledgement of the message burst or instead the acknowledgement of a message burst from another user equipment.

19. The apparatus of claim 13, wherein the processor is further configured to:

provide for transmission a portion of the message burst using a first narrow frequency range of the shared channel frequency range; and

provide for transmission another portion of the message burst using a second narrow frequency range of the shared channel frequency range different from the first narrow frequency range.

20. The apparatus of claim 13, wherein the processor is further configured to provide the preamble for transmission in part using a first narrow frequency range of the random access channel frequency range and in part using a second narrow frequency range of the random access channel frequency range different from the first.

21. The apparatus of claim 13, wherein the processor is further configured to obtain from the one or more messages indicating the acknowledgement a digest of the signature or a signature number, and determine whether the acknowledgment is an acknowledgement of the preamble sent by the user equipment or an acknowledgment of a message from another user equipment wireless communication device.

22. The apparatus of claim 13, wherein the processor is further configured to receive from the base station a further allocation of the shared channel for uplink of user data in response to the message burst, wherein the allocation is provided with the address provided by the user equipment, and wherein the message burst includes information bits providing information useable by the base station in determining the further allocation to assign to the user.

23. A user equipment wireless communication terminal, comprising:

an apparatus as in claim 13;

and

a radio front end for transmitting the preamble and the message burst, and for receiving the acknowledgement.

24. A method for use by a base station of a radio access network of a wireless communication system in communicating with a user equipment wireless communication terminal, comprising:

(a) receiving over a random access channel of the wireless communication system a message burst preamble and a signature; and

(b) providing for transmission one or more messages in response to the message burst preamble, wherein the one or more messages indicate an acknowledgment of having received the preamble and include a preamble identifier and a resource allocation of at least a portion of a shared channel; and

(c) receiving a message burst on the shared channel according to the resource allocation, decoding the message burst, and obtaining an address in the message burst for use in identifying the user equipment.

25. The method of claim 24, wherein the resource allocation is provided in a message separate from the message indicating the acknowledgment.

26. The method of claim 24, wherein when the user equipment has a temporary cell specific address the address included in the message burst is the temporary cell specific address.

27. The method of claim 24, further comprising:

providing for transmission to the user equipment a request to retransmit the message burst, and including the preamble identifier in the request in order to identify the message burst; and

receiving the retransmitted message burst and soft-combining the retransmitted message burst with previous transmissions of the message burst.

28. The method of claim 27, wherein the request to retransmit the message burst is a signal from the base station on a downlink shared control channel indicating an uplink resource allocation and including the preamble identifier.

29. The method of claim 24, further comprising providing an acknowledgement of the base station having received the message burst, wherein the acknowledgement is a signal from the base station on a downlink shared control channel indicating a downlink resource allocation and including the preamble identifier.

30. The method of claim 24, further comprising:

receiving a portion of the message burst using a first narrow frequency range of the shared channel frequency range; and

receiving another portion of the message burst using a second narrow frequency range of the shared channel frequency range different from the first narrow frequency range.

31. The method of claim 24, further comprising receiving the preamble in part in a first narrow frequency range of the random access channel frequency range and in part in a second narrow frequency range of the random access channel frequency range different from the first.

32. The method of claim 24, further comprising providing in the acknowledgement a digest of the signature or a signature number.

33. The method of claim 24, further comprising providing to the user equipment a further allocation of the shared channel for uplink of user data in response to the message burst, wherein the allocation is provided with the address provided by the user equipment, and wherein the base station decodes information bits included in the message burst and determines the further allocation at least in part based on the information bits.

34. A computer program product comprising a computer readable storage structure embodying computer program code thereon for execution by a computer processor, wherein said computer program code comprises instructions for performing a method according to claim 24.

35. An apparatus for use by a base station of a radio access network of a wireless communication system in communicating with a user equipment wireless communication terminal, comprising means for performing a method according to claim 24.

36. An apparatus for use by a base station of a radio access network of a wireless communication system in communicating with a user equipment wireless communication terminal, comprising a processor configured to:

(a) receive over a random access channel of the wireless communication system a message burst preamble and a signature; and

(b) provide for transmission one or more messages in response to the message burst preamble, wherein the one or more messages indicate an acknowledgment of having received the preamble and include a preamble identifier and a resource allocation of at least a portion of a shared channel; and

(c) receive a message burst on the shared channel according to the resource allocation, decode the message burst, and obtain an address from the message burst for use in identifying the user equipment.

37. The apparatus of claim 36, wherein the processor is further configured to provide the resource allocation in a message separate from the message indicating the acknowledgment.

38. The apparatus of claim 36, wherein when the user equipment has a temporary cell specific address the address included in the message burst is the temporary cell specific address.

39. The apparatus of claim 36, wherein the processor is further configured to:

provide for transmission to the user equipment a request to retransmit the message burst, and include the preamble identifier in the request in order to identify the message burst; and

receive the retransmitted message burst and soft-combine the retransmitted message burst with previous transmissions of the message burst.

40. The apparatus of claim 39, wherein the request to retransmit the message burst is a signal from the base station on a downlink shared control channel indicating an uplink resource allocation and including the preamble identifier.

41. The apparatus of claim 36, wherein the processor is further configured to provide an acknowledgement of the base station having received the message burst, wherein the acknowledgement is a signal from the base station on a downlink shared control channel indicating a downlink resource allocation and including the preamble identifier.

42. The apparatus of claim 36, wherein the processor is further configured to:

receive a portion of the message burst using a first narrow frequency range of the shared channel frequency range; and

receive another portion of the message burst using a second narrow frequency range of the shared channel frequency range different from the first narrow frequency range.

43. The apparatus of claim 36, wherein the processor is further configured to receive the preamble in part in a first narrow frequency range of the random access channel frequency range and in part in a second narrow frequency range of the random access channel frequency range different from the first.

44. The apparatus of claim 36, wherein the processor is further configured to provide in the acknowledgement a digest of the signature or a signature number.

45. The apparatus of claim 36, wherein the processor is further configured to provide to the user equipment a further allocation of the shared channel for uplink of user data in response to the message burst, wherein the allocation is provided with the address provided by the user equipment, and wherein the base station is further configured to decode information bits included in the message burst and determine the further allocation at least in part based on the information bits.

46. A base station of a radio access network of a wireless communication system, comprising:

an apparatus as in claim 36;

and

a radio front end for receiving the preamble and the message burst, and for transmitting the acknowledgment.

47. A system, comprising:

a plurality of base stations as in claim 46;

and

a plurality of user equipment terminals, configured for wirelessly coupling to the base stations.