Network node, user equipment and methods therein for random access handling

• US 8,995,395 B2
• Filed: 05/09/2012
• Issued: 03/31/2015
• Est. Priority Date: 05/09/2012
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Frenne, Mattias, Baldemair, Robert, Cheng, Jung-Fu, Larsson, Daniel
• Primary Examiner(s): Hailu, Kibrom T
• Application Number:
  US13/581,109
• Publication Number:
  US 20130301608A1
• Time in Patent Office: 1,056 Days
• US Class Current: 370/331
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 74/004 in the uplink, i.e. towards network
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

A method in a User Equipment (150), UE, for handling random access procedure to a wireless communications network via a network node (140), the UE (150) being configured to support transmissions on a Control CHannel, CCH, on an enhanced Control CHannel, eCCH, or on both. The method comprises sending (S160) a random access preamble to the network node, and receiving (S162) a random access response from the network node on at least one of the CCH or the eCCH. The random access preamble comprising a UE indication indicating that the UE is configured to monitor transmissions on the CCH, on the eCCH or on both;

A user equipment, a method in network node and a network node are also provided.

Claims

1. A method in a network node for handling random access procedures that provide User Equipments (UEs) access to a wireless communications network via the network node, wherein the network node supports both transmissions on a Control CHannel (CCH) and on an enhanced Control CHannel (eCCH), and the method comprises:

receiving a random access preamble from a UE in the wireless communications network, the random access preamble comprising a UE indication indicating whether the UE is configured to monitor transmissions on the CCH, on the eCCH, or on both; and

transmitting a random access response to the UE on at least one of the CCH and the eCCH, based on the received UE indication.

2. The method according to claim 1, wherein transmitting the random access response comprises transmitting the random access response to the UE on both the CCH and the eCCH.

3. The method according to claim 2, wherein the random access response schedules the same downlink assignments for resources for both the CCH and eCCH.

4. The method according to claim 1, wherein transmitting the random access response comprises:

determining whether the UE has indicated that the UE is configured to monitor transmissions on the CCH or on the eCCH based on the received UE indication;

transmitting the random access response to the UE on the CCH, based on determining that the UE has indicated that the UE is configured to monitor transmissions on the CCH; and

transmitting the random access response to the UE on the eCCH, based on determining that the UE has indicated that it monitors transmissions on the eCCH.

5. The method according claim 1, wherein the method comprises transmitting a system information message to the UE, informing the UE of supported transmissions on the CCH and the eCCH.

6. The method according to claim 5, wherein the method comprises transmitting the system information message to neighbouring network nodes, enabling the neighbouring nodes to provide the system information message to UEs during a handover procedure from one of the neighbouring network nodes to the network node.

7. The method according to claim 1, wherein the method comprises transmitting a system information message to the UE comprising a request requesting the UE to indicate which of the CCH or the eCCH the UE is configured to monitor transmissions on.

8. The method according to claim 1, wherein the UE indication is based on a use of any one or more of:

reserved preambles sequences and reserved time-frequency resources.

9. The method according to claim 1, wherein the CCH is a Physical Downlink Control CHannel (PDCCH) and the eCCH is an enhanced PDCCH (ePDCCH).

10. The method according to claim 1, further comprising transmitting a system information message that indicates first random access resources reserved for UEs that monitor the CCH and second random access resources reserved for UEs that monitor the eCCH, and wherein receiving the random access preamble from the UE comprises receiving the random access preamble via the first or second random access resources, and wherein the method further comprises determining the UE indication according to whether the UE used the first or the second random access resources to send the random access preamble.

11. The method of claim 10, further comprising sending the system information message to a neighbouring network node, thereby enabling the neighbouring network node to inform UEs being handed over to the network node of the first and second random access resources reserved by the network node.

12. A network node for handling of random access procedures providing User Equipments (UEs) access to a wireless communications network via the network node, wherein the network node is configured to support both transmissions on a control channel (CCH) and on an enhanced control channel (eCCH), and comprises transceiver circuitry configured to:

receive a random access preamble from a UE in the wireless communications network, the random access preamble comprising a UE indication indicating that the UE is configured to monitor transmissions on the CCH, on the eCCH, or on both; and

transmit a random access response to the UE on at least one of the CCH and the eCCH, based on the received UE indication.

13. The network node according to claim 12, wherein the transceiver circuitry is configured to transmit the random access response to the UE on both the CCH and the eCCH.

14. The network node according to claim 13, wherein the random access response schedules the same downlink assignments for resources for both the CCH and eCCH.

15. The network node according to claim 12, wherein the network node comprises processor circuitry configured to determine whether the UE has indicated that the UE is configured to monitor transmissions on the CCH or on the eCCH, based on the received UE indication, and wherein the transceiver circuitry is configured to:

transmit the random access response to the UE on the CCH, based on determining that the UE has indicated that the UE is configured to monitor transmissions on the CCH;

or,

transmit the random access response to the UE on the eCCH, based on determining that the UE has indicated that the UE is configured to monitor transmissions on the eCCH.

16. The network node according to claim 12, wherein the transceiver circuitry is configured to transmit a system information message to the UE, informing the UE of supported transmissions on the CCH and the eCCH.

17. The network node according to claim 12, wherein the transceiver circuitry is configured to transmit a system information message to the UE comprising a request requesting the UE to indicate which of the CCH and the eCCH the UE is configured to monitor transmission on.

18. The network node according to claim 16, wherein the transceiver circuitry is configured to transmit the system information message to neighbouring network nodes, enabling the neighbouring nodes to provide the system information message to UEs during a handover procedure from one of the neighbouring network nodes to the network node.

19. The network node according to claim 12, wherein the CCH is a Physical Downlink Control CHannel (PDCCH) and the eCCH is an enhanced PDCCH (ePDCCH).

20. The network node according to claim 12, wherein the transceiver circuitry is configured to transmit a system information message that indicates first random access resources reserved for UEs that monitor the CCH and second random access resources reserved for UEs that monitor the eCCH, and wherein the network node receives the random access preamble from the UE via the first or second random access resources, and further wherein the transceiver circuitry is configured to determine the UE indication according to whether the UE used the first or the second random access resources to send the random access preamble.

21. The network node of claim 20, wherein the transceiver circuitry is configured to send the system information message to a neighbouring network node, thereby enabling the neighboring network node to inform UEs being handed over to the network node of the first and second random access resources reserved by the network node.

22. A method in a User Equipment (UE) for handling random access procedures to a wireless communications network via a network node, wherein the UE supports transmissions on a Control CHannel (CCH), or on an enhanced Control CHannel (eCCH), or on both, and wherein the method comprises:

sending a random access preamble to the network node, the random access preamble comprising a UE indication indicating that the UE is configured to monitor transmissions on the CCH, on the eCCH, or on both; and

receiving a random access response from the network node on at least one of the CCH or the eCCH, enabling the UE to monitor the transmissions.

23. The method according to claim 22 wherein the receiving comprises receiving a random access response from the network node on both the CCH and the eCCH.

24. The method according to claim 23, wherein the random access response schedules the same downlink assignments for resources for both CCH and eCCH.

25. The method according to claim 22, wherein the sending is performed upon receiving a system information message from the network node, informing the UE of supported network node transmissions on the CCH and on the eCCH.

26. The method according to claim 22, wherein the method further comprises receiving a system information message from the network node, or from a target neighbour node to which the UE is handed over to, said system information message comprising a request requesting the UE to indicate which of the CCH and the eCCH the UE is configured to monitor transmissions on.

27. The method according to claim 22, wherein the UE indication is based on a use of any one or more of:

reserved preambles sequences and reserved time-frequency resources.

28. The method according to claim 22, wherein the CCH is a Physical Downlink Control CHannel (PDCCH) and the eCCH is an enhanced PDCCH (ePDCCH).

29. The method according to claim 22, wherein the receiving comprises receiving one or more timers, each indicating a time period for which the UE should monitor the CCH or the eCCH and when to switch monitoring from one of the monitored CCH and eCCH to the other one.

30. The method according to claim 22, further comprising receiving a system information message that indicates first random access resources reserved by the network node for UEs that monitor the CCH and indicates second random access resources reserved by the network node for UEs that monitor the eCCH, and wherein sending the random access preamble to the network node comprises one of:

sending the random access preamble using the first random access resources, to thereby indicate that the UE monitors the CCH; and

sending the random access preamble using the second random access resources, to thereby indicate that the UE monitors the eCCH.

31. A User Equipment (UE) configured for handling a random access procedure to a wireless communications network via a network node, wherein the UE is configured to support transmissions on a Control CHannel (CCH), or on an enhanced Control CHannel (eCCH), or on both, and further wherein the UE comprises transceiver circuitry configured to:

send a random access preamble to the network node, the random access preamble comprising a UE indication indicating that the UE is configured to monitor transmissions on the CCH, on the eCCH or on both; and

,

receive a random access response from the network node, on at least one of the CCH or the eCCH, enabling the UE to monitor the transmissions.

32. The UE according to claim 31, wherein the transceiver circuitry is configured to receive a random access response from the network node, on both the CCH and the eCCH.

33. The UE according to claim 31, wherein the transceiver circuitry is configured to receive a system information message from the network node, and wherein the UE comprises a processor circuitry configured to determine whether the received system information message includes information indicating supported network node transmissions on the CCH and on the eCCH.

34. The UE according to claim 31, wherein the UE indication indicates the UE configuration and is based on a use by the UE of any one or more of:

reserved preambles sequences or reserved time-frequency resources.

35. The UE according to claim 31, wherein the transceiver circuitry is configured to retrieve, or receive from the network node, one or more timers, each indicating a time period for which the UE should monitor the CCH or the eCCH and when to switch monitoring from one of the monitored CCH and eCCH to the other one.

36. The UE according to claim 31, wherein the transceiver circuitry is configured to receive a system information message that indicates first random access resources reserved by the network node for UEs that monitor the CCH and indicates second random access resources reserved by the network node for UEs that monitor the eCCH, and to send the random access preamble to the network node using the first random access resources, to thereby indicate that the UE monitors the CCH, or using the second random access resources, to thereby indicate that the UE monitors the eCCH.