# US 2019/0174408 A1 · Implicit DRX Cycle Length Adjustment Control in LTE Active Mode

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2019/0174408 A1
- Document ID: US20190174408A1
- Status: Published application
- Kind: A1
- Application number: 16/256,121
- Filed: 2019-01-24
- Published: 2019-06-06
- Earliest claimed: 2007-01-30
- Assignees: InterDigital Technology Corporation
- Applicants: InterDigital Technology Corporation
- Inventors: Stephen E. Terry; Peter S. Wang; Jin Wang
- Web page: https://patentgrep.com/patent/US20190174408A1

## CPC

- H04W 52/0212: {managed by the network, e.g. network or access point is leader and terminal is follower}
- H04W 52/0229: {where the received signal is a wanted signal}
- H04W 52/0235: {where the received signal is a power saving command}
- H04W 76/28: Discontinuous transmission [DTX]; Discontinuous reception [DRX]
- H04W 52/0216: {using a pre-established activity schedule, e.g. traffic indication frame}
- Y02D 30/70: in wireless communication networks
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE

## Abstract

A method for controlling discontinuous reception in a wireless transmit/receive unit includes defining a plurality of DRX levels, wherein each DRX level includes a respective DRX cycle length and transitioning between DRX levels based on a set of criteria. The transitioning may be triggered by implicit rules.

## Claims

### Claim 1

A method implemented by a wireless transmit/receive unit (WTRU), the method comprising:
the WTRU receiving a radio resource control (RRC) message, the RRC message comprising information elements (IEs) that indicate a first DRX cycle length and a second DRX cycle length;
the WTRU receiving a DRX trigger;
the WTRU determining whether to perform DRX using the first DRX cycle length indicated in the RRC message or the second DRX cycle length indicated in the RRC message based on the received DRX trigger, wherein the WTRU performs DRX using the first DRX cycle length if the received DRX trigger is a first type of DRX trigger and the WTRU performs DRX using the second DRX cycle length if the received DRX trigger is a second type of DRX trigger, the second DRX cycle length being a multiple of the first DRX cycle length; and
the WTRU performing DRX using the DRX cycle length indicated by the received DRX trigger.

### Claim 2 (depends on 1)

The method as in claim 1, wherein the received DRX trigger is the first type of DRX trigger, and the method further comprises:
the WTRU starting a DRX cycle length transition timer;
the WTRU determining that the DRX cycle length transition timer has expired;
the WTRU transitioning to the second DRX cycle length upon determining the that DRX cycle length transition timer has expired.

### Claim 3 (depends on 2)

The method as in claim 2, wherein the second DRX cycle length corresponds to normal DRX cycle length.

### Claim 4 (depends on 2)

The method as in claim 2, wherein the DRX cycle length transition timer is started upon beginning DRX operation using the first DRX cycle length,

### Claim 5 (depends on 2)

The method as in claim 2, wherein a length of the DRX cycle length transition timer corresponds to a resume period.

### Claim 6 (depends on 1)

The method as in claim 1, wherein the received DRX trigger comprises a downlink command.

### Claim 7 (depends on 1)

The method as in claim 1, wherein the DRX trigger is implemented a medium access control (MAC) level.

### Claim 8

A wireless transmit/receive unit (WTRU) comprising a processor and memory configured to:
receive a radio resource control (RRC) message, the RRC message comprising information elements (IEs) that indicate a first DRX cycle length and a second DRX cycle length;
receive a DRX trigger;
determine whether to perform DRX using the first DRX cycle length indicated in the RRC message or the second DRX cycle length indicated in the RRC message based on the received DRX trigger, wherein the WTRU is configured to perform DRX using the first DRX cycle length if the received DRX trigger is a first type of DRX trigger and the WTRU is configured to perform DRX using the second DRX cycle length if the received DRX trigger is a second type of DRX trigger, the second DRX cycle length being a multiple of the first DRX cycle length; and
perform DRX using the DRX cycle length indicated by the received DRX trigger.

### Claim 9 (depends on 8)

The WTRU as in claim 8, wherein the received DRX trigger is the first type of DRX trigger, and the processor and memory are further configured to:
start a DRX cycle length transition timer;
determine that the DRX cycle length transition timer has expired;
transition to the second DRX cycle length upon determining the that DRX cycle length transition timer has expired.

### Claim 10 (depends on 9)

The WTRU as in claim 9, wherein the second DRX cycle length corresponds to normal DRX cycle length.

### Claim 11 (depends on 9)

The WTRU as in claim 9, where the DRX cycle length transition timer is started upon beginning DRX operation using the first DRX cycle length.

### Claim 12 (depends on 9)

The WTRU as in claim 9, wherein a length of the DRX cycle length transition timer corresponds to a resume period.

### Claim 13 (depends on 8)

The WTRU as in claim 8, wherein the received DRX trigger comprises a downlink command.

### Claim 14 (depends on 8)

The WTRU as in claim 8, wherein the DRX trigger is implemented a medium access control (MAC) level.

### Claim 15

A base station comprising a processor and memory configured to:
send a radio resource control (RRC) message to a wireless transmit/receive unit (WTRU), the RRC message comprising information elements (IEs) that indicate a first DRX cycle length and a second DRX cycle length; and
send a DRX trigger to the WTRU, wherein the DRX trigger is one of a first type of DRX trigger or a second type of DRX trigger, wherein the first type of DRX trigger indicates to the WTRU that the WTRU should perform DRX using the first DRX cycle length and the second type of DRX trigger indicates to the WTRU that the WTRU should perform DRX using the second DRX cycle length, the first DRX cycle length being a multiple of the first DRX cycle length.

### Claim 16 (depends on 15)

The base station as in claim 15, wherein the DRX trigger is the first type of DRX trigger, and the processor and memory are further configured to:
determine that the WTRU has transitioned from the first DRX cycle length to the second DRX cycle length based on a DRX cycle length transition timer at the WTRU having expired.

### Claim 17 (depends on 16)

The base station as in claim 16, wherein processor and memory are configured to determine that determine that the WTRU has transitioned from the first DRX cycle length to the second DRX cycle length based on expiry of a base station timer that is synchronized with the DRX cycle length transition timer at the WTRU.

### Claim 18 (depends on 15)

The base station as in claim 15, wherein the DRX trigger comprises a downlink command.

### Claim 19 (depends on 15)

The base station as in claim 15, wherein the DRX trigger is implemented a medium access control (MAC) level.

### Claim 20 (depends on 15)

The base station as in claim 15, wherein the base station comprises an eNB.