RANDOM ACCESS PROCEDURE FOR ENHANCED COVERAGE SUPPORT

• US 20160302234A1
• Filed: 09/22/2015
• Published: 10/13/2016
• Est. Priority Date: 04/09/2015
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Intel IP Corporation (Intel Corporation)
• Inventors: Martinez Tarradell, Marta, Choi, Hyung-Nam, Chatterjee, Debdeep, Burbidge, Richard, Heo, Youn Hyoung, Phuyal, Umesh
• Granted Patent: US 9,918,344 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 1/00 Arrangements for detecting or preventing errors in the information received correcting synchronisation H04L7/00
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04W 52/22 taking into account previous information or commands
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

Embodiments described herein relate generally to a communication between a user equipment (UE) and an evolved Node B (eNB) that are both running in Enhanced Coverage (EC) mode. The UE and eNB may communicate in a contention-based random access procedure having an EC level that may be used to determine the number of times an RA preamble may be sent, and one or more RA response opportunity windows that may be used to receive one or more RA responses. Other embodiments may be described and/or claimed.

Claims

1. An apparatus to be employed in a user equipment, UE, the apparatus comprising:

one or more processors;

a memory coupled to the one or more processors having instructions thereon that when executed cause the processors to;

identify an initial enhanced coverage, EC, level that is to be used in a radio cell during a contention-based random access, RA, procedure, the EC level having at least an associated power level, window of time, and number of send attempts;

send a first message to a radio access network, RAN, based on the identified EC level;

determine whether a second message from the RAN in response to the first message is received within the window of time;

if the second message is received from the eNB within the window of time, decode the received second message; and

if the second message is not received from the eNB within the window of time;

re-send the first message to the RAN.

2. The apparatus of claim 1, wherein the RAN includes at least one enhanced NodeB, eNB.

3. The apparatus of claim 1, wherein re-send the first message to the RAN further comprises:

track a number of times the first message has been sent using a transmission counter having a numerical value; and

output an indication that the RA EC procedure did not complete successfully based on determination of a whether the second message is received within a window of time and a comparison of the transmission counter to a transmission threshold value.

4. The apparatus of claim 1, wherein the first message is a random access, RA, preamble and the second message is a random access response, RAR.

5. The apparatus of claim 1, wherein an initial EC level is configured in the UE or is received in a system information block, SIB.

6. The apparatus of claim 5, wherein the SIB is received in a higher bandwidth or in a reduced bandwidth.

7. The apparatus of claim 1, wherein the power level at which the first message is sent is based on one or more of:

the value of the transmission counter, or the value of the EC level.

8. The apparatus of claim 1, wherein re-send the first message further includes power ramping.

9. The apparatus of claim 8, wherein the power ramping includes increasing the power to a maximum power level associated with the EC level.

10. The apparatus of claim 1, wherein the window of time is dependent at least on a number of EC RAR opportunities defined within an EC RAR window and/or the number of send attempts for the EC level.

11. The apparatus of claim 1, wherein re-send the first message to the RAN further comprises:

include a delay time before re-sending the first message, the delay being one of a function of at least the EC level.

12. The apparatus of claim 1, wherein the UE may be capable to operate in a normal coverage mode and in EC mode.

13. An apparatus to be employed in an evolved NodeB, eNB, the apparatus comprising:

one or more processors;

a memory coupled to the one or more processors having instructions thereon that when executed cause the processors to;

determine enhanced coverage, EC, levels to be used in a radio cell during a contention-based random access, RA, procedure,

send, in a system information block, SIB, to a user equipment, UE, located in the radio cell, an indication of the determined EC levels;

receive an RA preamble from a UE,

responsive to the RA preamble, transmit a random access response, RAR, message.

14. The eNB of claim 13, wherein send in a SIB an indication of the determined EC levels further includes send in a reduced bandwidth of 1.4 megahertz or 200 kilohertz.

15. The eNB of claim 13, wherein the eNB may be to operate a radio cell in normal coverage mode and in EC mode.

16. An apparatus to be employed in a user equipment, UE, the apparatus comprising:

logic circuitry to identify an enhanced coverage, EC level;

transmit circuitry to send to a radio access network, RAN, a random access, RA, preamble based on the identified EC level;

logic circuitry to identify an EC random access response, RAR, window region having a plurality of subframes.

17. The apparatus of claim 16, further comprising:

logic circuitry to identify an EC random access response, RAR, window region having a plurality of subframes, the EC RAR window region including one or more EC RAR opportunities, each being a contiguous group of subframes, the first EC RAR opportunity beginning at the same sub-frame as the beginning of the RAR window region and beginning K subframes after the RA preamble was sent.

18. The apparatus of claim 17, further comprising receive circuitry to:

receive, from the RAN, a candidate RAR in the first EC RAR opportunity;

until a candidate RAR is able to be decoded, receive, from the RAN, a candidate RAR from an EC RAR opportunity; and

if a candidate RAR is able to be decoded, send, to the RAN, an RRC connection request.

19. The apparatus of claim 16, wherein the EC RAR window region is dependent on a value:

defined in the specification,

broadcast as a part of the SI message,

associated with the EC level, or

associated with the number of the subframes in EC RAR opportunities that contain an RAR message.

20. An evolved NodeB, eNB, comprising:

control circuitry to identify a system information, SI, modification period associated with a radio cell configuration from a plurality of SI modification periods when in reduced bandwidth mode; and

transmit circuitry coupled with the control circuitry, the transmit circuitry to transmit an SI message in accordance with the identified modification period.

21. The apparatus of claim 20, wherein the control circuitry and transmit circuitry are to operate in normal coverage mode and/or in EC mode.

22. The apparatus of claim 20, wherein the control circuitry further defines the modification periods for SI parameters associated with the radio cell configuration with a same value as a normal coverage user equipment, UE.