USER EQUIPMENT AND METHOD FOR MANAGING BACKOFF TIME IN THE USER EQUIPMENT

• US 20140079013A1
• Filed: 05/07/2012
• Published: 03/20/2014
• Est. Priority Date: 05/06/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Sang Bum, Jeong, Kyeong In, Kim, Soeng Hun, Jang, Jae Hyuk
• Granted Patent: US 10,771,227 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 5/0085 when channel conditions change
• CPC Class Codes: H04W 28/0215 based on user or device properties, e.g. MTC-capable devices services for machine-to-machine communication [M2M] or machine type communication [MTC] H04W4/70; wireless resource selection or allocation plan definition based on terminal or device properties H04W72/51
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

The present invention relates to a method for efficiently controlling an MTC device attempting a delay tolerant access in a 3GPP system. The present invention provides a method for effectively providing a backoff time to prevent load on a wireless network, which can occur when many MTC devices in a single cell simultaneously attempt access.

Claims

1. A backoff time management method of a terminal, the method comprising:

determining whether a system information block received from a base station includes a backoff indicator;

calculating, when the backoff indicator is included, the backoff time using backoff indicator information;

delaying preamble transmission time for initial random access as much as the calculated backoff time; and

transmitting the preamble when the backoff time expires.

2. The method of claim 1, wherein the calculating of the backoff time comprises:

acquiring Random Access Response scheduling information from a downlink control channel;

storing the backoff indicator information included in the random access response scheduling information; and

determining the backoff time using a backoff parameter of the stored backoff indicator information.

3. The method of claim 1, wherein the calculating of the backoff time comprises determining the backoff time using the backoff parameter included in predefined backoff indicator information.

4. The method of claim 1, further comprising:

transmitting, when the backoff indicator is not included, the preamble for the initial random access;

calculating, when a random access response is not received in response to the preamble, the backoff time; and

retrying random access after the calculated backoff time.

5. The method of claim 1, further comprising:

determining whether a delay tolerant access is required; and

determining, when the delay tolerant access is required, whether the system information block includes the backoff indicator.

6. A backoff time management terminal comprising:

a transceiver which receives a system information block from a base station; and

a controller which determines whether a system information block received from a base station includes a backoff indicator, calculates, when the backoff indicator is included, the backoff time using backoff indicator information, delays preamble transmission time for initial random access as much as the calculated backoff time, and transmits the preamble when the backoff time expires.

7. The terminal of claim 6, wherein the controller acquires random access response scheduling information from a downlink control channel and determines the backoff time using a backoff parameter of the stored backoff indicator information included in the random access response scheduling information.

8. The terminal of claim 6, wherein the controller determines the backoff time using the backoff parameter included in predefined backoff indicator information.

9. The terminal of claim 6, wherein the controller transmits, when the backoff indicator is not included, the preamble for the initial random access, calculates, when a random access response is not received in response to the preamble, the backoff time, and retries random access after the calculated backoff time.

10. The terminal of claim 6, wherein the controller determines whether a delay tolerant access is required and determines when the delay tolerant access is required, whether the system information block includes the backoff indicator.