# US 2020/0288502 A1 · Method for performing a random access procedure in bandwidth part (bwp) operation in wireless communication system and a device therefor

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- Number: US 2020/0288502 A1
- Document ID: US20200288502A1
- Status: Published application
- Kind: A1
- Application number: 16/652,981
- Filed: 2018-10-23
- Published: 2020-09-10
- Earliest claimed: 2017-10-27
- Assignees: LG Electronics Inc.
- Applicants: LG Electronics Inc.
- Inventors: Eunjong LEE; Sunyoung LEE
- Web page: https://patentgrep.com/patent/US20200288502A1

## CPC

- H04L 5/0098: {Signalling of the activation or deactivation of component carriers, subcarriers or frequency bands}
- H04W 74/08: Non-scheduled access, e.g. ALOHA (hybrid access H04W74/02)
- H04L 5/0092: {Indication of how the channel is divided}
- H04W 24/08: Testing, {supervising or monitoring} using real traffic
- H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal
- H04W 74/0833: Random access procedures, e.g. with 4-step access
- H04W 74/0891: {for synchronized access}
- H04W 72/0453: Resources in frequency domain, e.g. a carrier in FDMA
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

The present invention relates to a wireless communication system. More specifically, the present invention relates to a method and a device for performing a random access procedure in BWP operation in wireless communication system, the method comprising: starting a timer related to timing alignment of a Timing Advance Group (TAG) to which a serving cell belongs; switching an active Downlink (DL) Bandwidth Part (BWP) of the serving cell from a first DL BWP to a second DL BWP, when the timer expires; and monitoring a downlink control channel on the second DL BWP. The device is capable of communicating with at least one of another UE, a UE related to an autonomous driving vehicle, a base station or a network.

## Claims

### Claim 1

A method for a communication device operating in a wireless communication system, the method comprising:
starting a timer related to timing alignment of a Timing Advance Group (TAG) to which a serving cell belongs;
switching an active Downlink (DL) Bandwidth Part (BWP) of the serving cell from a first DL BWP to a second DL BWP, when the timer expires; and
monitoring a downlink control channel on the second DL BWP.

### Claim 2 (depends on 1)

The method according to claim 1, further comprising:
transmitting a Random Access Preamble (RAP) on an active uplink (UL) BWP; and
monitoring Random Access Response (RAR) in response to the RAP on the second DL BWP.

### Claim 3 (depends on 2)

The method according to claim 2, wherein the RAP is transmitted based on Contention-Based Random Access (CBRA) procedure.

### Claim 4 (depends on 1)

The method according to claim 1, wherein the active DL BWP of the serving cell is switched from the first DL BWP to the second DL BWP, although a timer related to the first DL BWP of a serving cell is running, when the timer expires,
wherein the timer related to the first DL BWP of the serving cell is started when the first DL BWP is activated.

### Claim 5 (depends on 1)

The method according to claim 1, wherein the active UL BWP is switched to a default UL BWP or an initial UL BWP when the active DL BWP is switched from the first DL BWP to the second DL BWP.

### Claim 6 (depends on 1)

The method according to claim 1, wherein the second DL BWP is a default DL BWP or an initial DL BWP.

### Claim 7 (depends on 1)

The method according to claim 1, when the timer expires, Physical Uplink Control Channel (PUCCH) resources for all serving cells belonging to the TAG are released.

### Claim 8

A communication device for operating in a wireless communication system, the communication device comprising:
a memory; and
a processor operably coupled with the memory module and configured to:
start a timer related to timing alignment of a Timing Advance Group (TAG) to which a serving cell belongs;
switch an active Downlink (DL) Bandwidth Part (BWP) of the serving cell from a first DL BWP to a second DL BWP, when the timer expires; and
monitor a downlink control channel on the second DL BWP.

### Claim 9 (depends on 8)

The communication device according to claim 8, wherein the processor is further configured to transmit a Random Access Preamble (RAP) on an active uplink (UL) BWP, and to monitor Random Access Response (RAR) in response to the RAP on the second DL BWP.

### Claim 10 (depends on 9)

The communication device according to claim 9, wherein the RAP is transmitted based on Contention-Based Random Access (CBRA) procedure.

### Claim 11 (depends on 8)

The communication device according to claim 8, wherein the active DL BWP of the serving cell is switched from the first DL BWP to the second DL BWP, although a timer related to the first DL BWP of a serving cell is running, when the timer expires, wherein the timer related to the first DL BWP of the serving cell is started when the first DL BWP is activated.

### Claim 12 (depends on 8)

The communication device according to claim 8, wherein the active UL BWP is switched to a default UL BWP or an initial UL BWP when the active DL BWP is switched from the first DL BWP to the second DL BWP.

### Claim 13 (depends on 8)

The communication device according to claim 8, wherein the second DL BWP is a default DL BWP or an initial DL BWP.

### Claim 14 (depends on 8)

The communication device according to claim 8, when the timer expires, Physical Uplink Control Channel (PUCCH) resources for all serving cells belonging to the TAG are released.

### Claim 15 (depends on 8)

The communication device according to claim 8, wherein the communication device is capable of communicating with at least one of another device, a device related to an autonomous driving vehicle, a base station or a network.