Efficient uplink timing synchronization for fixed-location m2m terminals

Patent metadata

Field	Value
Publication number	US-2016295532-A1
Application number	US-201514674982-A
Country	US
Kind code	A1
Filing date	Mar 31, 2015
Priority date	Mar 31, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

A method for determining synchronization of uplink timing in a machine type communication (MTC) system comprising a machine type communication device (MTCD) and a network element is disclosed that takes advantage of the MTCD being at a fixed location relative to the network element. The method includes receiving at the MTCD an uplink timing adjustment value from the network element and storing the uplink timing adjustment value at the MTCD. The MTCD then uses the stored uplink timing adjustment value from a previous uplink transmission for synchronizing uplink timing for a subsequent uplink transmission from the MTCD to the network element even following a period of inactivity of the MTCD, or expiration of any existing maximum uplink timing alignment period permitted for use of the timing adjustment value by the MTCD, or MTCD clock drift.

First claim

1 . A method for determining uplink timing for a next uplink transmission from a machine type communication device (MTCD) to a network element in a machine-type communication (MTC) system, the method comprising:
calculating a downlink synchronization at the MTCD on a downlink frame received at the MTCD from the network element; and using the downlink synchronization together with a stored uplink timing adjustment value from a previous uplink transmission from the MTCD to the network element to calculate the uplink timing for the next uplink transmission from the MTCD to the network element.

2 . The method of claim 1 , wherein the MTCD undergoes a period of inactivity between the previous uplink transmission and the next uplink transmission.

3 . The method of claim 2 , wherein the period of inactivity is greater than an uplink timing alignment period.

4 . The method of claim 1 , wherein an internal timing element of the MTCD drifts relative to a timing element of the network element between the previous uplink transmission and the next uplink transmission.

5 . The method of claim 1 , wherein the MTCD is at a fixed location relative to the network element.

6 . The method of claim 1 , wherein the previous uplink transmission is part of an initial access procedure.

7 . A method for determining uplink timing for an uplink transmission from a machine type communication device (MTCD) to a network element in a machine type communication (MTC) system, the method comprising:
calculating a downlink synchronization at the MTCD on a downlink frame received at the MTCD from the network element; and using the downlink synchronization without using an uplink timing adjustment value to calculate the uplink timing for the uplink transmission from the MTCD to the network element.

8 . The method of claim 7 , wherein the MTCD is at a fixed location relative to the network element.

9 . The method of claim 7 , wherein the MTCD moves relative to the network element before receiving the downlink frame from the network element.

10 . The method of claim 7 , wherein an internal timing element of the MTCD drifts relative to a timing element of the network element before the MTCD receives the downlink frame from the network element.

11 . The method of claim 7 , wherein the MTCD undergoes a period of inactivity before the MTCD receives the downlink frame from the network element.

12 . The method of claim 11 , wherein the period of inactivity is greater than an uplink timing alignment period.

13 . A machine-type communication device (MTCD) for determining uplink timing for a next uplink transmission from the MTCD to a network element in a machine-type communication (MTC) system, the MTCD comprising a processor configured to:
calculate a downlink synchronization on a downlink frame received at the MTCD from the network element; and use the downlink synchronization together with a stored uplink timing adjustment value from a previous uplink transmission from the MTCD to the network element to calculate the uplink timing for the next uplink transmission from the MTCD to the network element.

14 . The MTCD of claim 13 , wherein the MTCD undergoes a period of inactivity between the previous uplink transmission and the next uplink transmission.

15 . The MTCD of claim 14 , wherein the period of inactivity is greater than an uplink timing alignment period.

16 . The MTCD of claim 13 , wherein an internal timing element of the MTCD drifts relative to a timing element of the network element between the previous uplink transmission and the next uplink transmission.

17 . The MTCD of claim 13 , wherein the MTCD is at a fixed location relative to the network element.

18 . The MTCD of claim 13 , wherein the previous uplink transmission is part of an initial access procedure.

19 . A machine type communication device (MTCD) for determining uplink timing for an uplink transmission from the MTCD to a network element in a machine type communication (MTC) system, the MTCD comprising a processor configured to:
calculate a downlink synchronization at the MTCD on a downlink frame received at the MTCD from the network element; and use the downlink synchronization without using an uplink timing adjustment value to calculate the uplink timing for the uplink transmission from the MTCD to the network element.

20 . The MTCD of claim 19 , wherein the MTCD is at a fixed location relative to the network element.

21 . The MTCD of claim 19 , wherein the MTCD moves relative to the network element before receiving the downlink frame from the network element.

22 . The MTCD of claim 19 , wherein an internal timing element of the MTCD drifts relative to a timing element of the network element before the MTCD receives the downlink frame from the network element.

23 . The MTCD of claim 19 , wherein the MTCD undergoes a period of inactivity before the MTCD receives the downlink frame from the network element.

24 . The MTCD of claim 23 , wherein the period of inactivity is greater than an uplink timing alignment period.

Assignees

• Huawei Tech Co Ltd

Inventors

• Cao Yu
• Jia Ming

Classifications

• H04W56/001 Primary

  Synchronization between nodes · CPC title

• H04W4/005

  Electricity · mapped topic

• H04W4/70

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