Cell selection procedures for machine type communication devices

Patent metadata

Field	Value
Publication number	US-10117152-B2
Application number	US-201615148818-A
Country	US
Kind code	B2
Filing date	May 6, 2016
Priority date	May 13, 2015
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

Cell selection techniques are provided for network access to cells that may employ one or more coverage enhancement techniques. A user equipment (UE), which may be a machine type communication (MTC) device, upon initial acquisition or upon wakeup may measure a reference signal received power (RSRP), reference signal received quality (RSRQ), or both, and determine a cell selection value based at least in part on the RSRP, RSRQ, or a combination thereof. The cell selection value may be determined based on an offset, which may be selected based on a measurement accuracy capability of the UE. UE sequential access attempts, neighbor cell list information that may include coverage enhancement of neighboring cells transmissions, and cell re-selection measurement frequency adjustments are also described.

First claim

What is claimed is:

1. A method of wireless communication in a wireless communications network, comprising:
measuring a parameter of a signal received from a cell;
determining that the cell does not satisfy a cell selection criterion based at least in part on comparing the measured parameter of the received signal to a first threshold;
determining a second threshold when the cell supports coverage enhancement;
comparing the measured parameter of the received signal to the second threshold to determine whether the cell satisfies the cell selection criterion when in coverage enhancement;
selecting the cell for network access when the cell satisfies the cell selection criterion in coverage enhancement; and
transmitting an access request to the cell based at least in part on the selecting.

2. The method of claim 1 , wherein the cell comprises a serving cell or a neighboring cell.

3. The method of claim 1 , further comprising:
determining an offset to apply to the first threshold for the cell based at least in part on a coverage enhancement level for the cell.

4. The method of claim 1 , wherein the parameter is based at least in part on one or both of a reference signal received power (RSRP) measurement or a reference signal received quality (RSRQ) measurement.

5. The method of claim 1 , wherein determining that the cell does not satisfy the cell selection criterion comprises:
determining that a the measured parameter is less than the first threshold.

6. The method of claim 1 , wherein selecting the cell for network access comprises:
continuing to select an additional cell for network access according to a predefined criteria.

7. The method of claim 6 , wherein continuing to select the additional cell comprises:
attempting to decode a broadcast channel transmission of the cell; and
selecting the additional cell for access to the wireless communications network based at least in part on unsuccessfully attempting to decode the broadcast channel transmission of the cell.

8. The method of claim 7 , wherein attempting to decode the broadcast channel transmission of the cell comprises attempting to decode a physical broadcast channel (PBCH) and system information block (SIB) of the cell.

9. The method of claim 1 , further comprising:
determining that a reference signal density for the cell is adjusted based at least in part on a coverage enhancement level for the cell; and
adjusting a measurement duration associated with the signal based at least in part on the reference signal density.

10. The method of claim 9 , wherein the reference signal density is increased as a function of the coverage enhancement level.

11. The method of claim 9 , wherein the measurement duration associated with the signal is increased as a function of the coverage enhancement level.

12. An apparatus for wireless communication, comprising:
a processor;
memory in electronic communication with the processor; and
instructions stored in the memory and operable, when executed by the processor, to cause the apparatus to:
measure a parameter of a signal received from a cell;
determine that the cell does not satisfy a cell selection criterion based at least in part on comparing the measured parameter of the received signal to a first threshold;
determine a second threshold when the cell supports coverage enhancement;
compare the measured parameter of the received signal to the second threshold to determine whether the cell satisfies the cell selection criterion when in coverage enhancement;
select the cell for network access when the cell satisfies the cell selection criterion in coverage enhancement; and
transmit an access request to the cell based at least in part on the selecting.

13. The apparatus of claim 12 , wherein the cell comprises a serving cell or a neighboring cell.

14. The apparatus of claim 12 , wherein the instructions are further executable to cause the apparatus to:
determine an offset to apply to the first threshold for the cell based at least in part on a coverage enhancement level for the cell.

15. The apparatus of claim 12 , wherein the parameter is based at least in part on one or both of a reference signal received power (RSRP) measurement or a reference signal received quality (RSRQ) measurement.

16. The apparatus of claim 12 , wherein the instructions to compare the measured parameter of the received signal to the first threshold are further executable to cause the apparatus to:
determine that the measured parameter is less than the first threshold.

17. The apparatus of claim 12 , wherein the instructions to select are further executable to cause the apparatus to:
continue to select an additional cell for network access according to a predefined criteria.

18. The apparatus of claim 17 , wherein the instructions to continue to select the additional cell are further executable to cause the apparatus to:
attempt to decode a broadcast channel transmission of the cell; and
select the additional cell for access to a wireless communications network based at least in part on unsuccessfully attempting to decode the broadcast channel transmission of the cell.

19. The apparatus of claim 18 , wherein the instructions to attempt to decode the broadcast channel transmission of the cell are further executable to cause the apparatus to attempt to decode a physical broadcast channel (PBCH) and system information block (SIB) of the cell.

20. The apparatus of claim 12 , wherein the instructions are further executable to cause the apparatus to:
determine that a reference signal density for the cell is adjusted based at least in part on a coverage enhancement level for the cell; and
adjust a measurement duration associated with the signal based at least in part on the reference signal density.

Assignees

• Qualcomm Inc

Inventors

• Wang Renqiu
• Vajapeyam Madhavan Srinivasan
• Xu Hao
• Chen Wanshi
• Gaal Peter

Classifications

• H04W4/70 Primary

  Services for machine-to-machine communication [M2M] or machine type communication [MTC] · CPC title

• H04H20/38

  Arrangements for distribution where lower stations, e.g. receivers, interact with the broadcast · CPC title

• H04W72/0473

  the resource being transmission power · CPC title

• H04W48/20 Primary

  Selecting an access point · CPC title

• H04L5/005

  of common pilots, i.e. pilots destined for multiple users or terminals · CPC title