# US 10,374,683 B2 · Apparatus and method for beam failure recovery

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- Number: US 10,374,683 B2
- Document ID: US10374683B2
- Status: Granted
- Kind: B2
- Application number: 15/796,449
- Filed: 2017-10-27
- Published: 2019-03-07
- Granted: 2019-08-06
- Earliest claimed: 2017-09-07
- Assignees: Futurewei Technologies, Inc.
- Applicants: Futurewei Technologies, Inc.
- Inventors: Young Hoon Kwon; Bin Liu; Pengfei Xia
- Web page: https://patentgrep.com/patent/US10374683B2

## CPC

- H04B 7/06964: {Re-selection of one or more beams after beam failure}
- H04B 7/06966: {using beam correspondence; using channel reciprocity, e.g. downlink beam training based on uplink sounding reference signal [SRS]}
- H04B 7/18582: {Arrangements for data linking, i.e. for data framing, for error recovery, for multiple access}
- H04L 5/00: Arrangements affording multiple use of the transmission path
- H04L 5/0023: {Time-frequency-space}
- H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)}
- H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals}
- H04W 56/0005: {synchronizing of arrival of multiple uplinks}
- H04W 56/003: {Arrangements to increase tolerance to errors in transmission or reception timing}
- H04W 74/0833: Random access procedures, e.g. with 4-step access
- H04W 16/28: using beam steering
- H04W 72/046: {the resource being in the space domain, e.g. beams}
- H04W 74/0838: using contention-free random access [CFRA]
- H04B: TRANSMISSION
- 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 disclosure relates to technology for assigning resources to user equipment for a beam failure recovery by a base station. The base station identifies a beam failure random access channel (BRACH) resource holding beam correspondence with a synchronization signal (SS) block resource covering the user equipment, and assigns the user equipment one or more BRACH preambles for each BRACH resource assigned to the user equipment, excluding the BRACH resource holding beam correspondence with the SS block resource covering the user equipment.

## Claims

### Claim 1

A method for assigning resources to user equipment for a beam failure recovery by a base station, comprising: identifying a beam failure random access channel (BRACH) resource holding beam correspondence with a synchronization signal (SS) block resource covering the user equipment; and assigning the user equipment one or more BRACH preambles for each BRACH resource assigned to the user equipment, excluding the BRACH resource holding beam correspondence with the SS block resource covering the user equipment.

### Claim 2 (depends on 1)

The method of claim 1, further comprising: transmitting one or more of the SS block resources, where each of the SS block resources has a different beam direction.

### Claim 3 (depends on 2)

The method of claim 2, wherein the BRACH resource supports N*(K/(K−1)) user equipment, where N is a number of user equipment and K is a number of BRACH resources with different beams.

### Claim 4 (depends on 1)

The method of claim 1, wherein when the user equipment has more than one SS block resource in use, the base station does not assign a BRACH preamble for the user equipment on the BRACH resources holding beam correspondence with the SS block resources in use.

### Claim 5 (depends on 1)

The method of claim 1, further comprising: receiving a beam failure recovery request (BFRR) from the user equipment, including identification of a different SS block resource as a new candidate beam, upon detection of a beam failure between the base station and the user equipment; and identifying the new candidate beam upon receiving a BRACH preamble assigned for the user equipment at the BRACH resource.

### Claim 6

A device for assigning resources to user equipment for a beam failure recovery by a base station, comprising: a non-transitory memory storage comprising instructions; and one or more processors in communication with the memory, wherein the one or more processors execute the instructions to: identify a beam failure random access channel (BRACH) resource holding beam correspondence with a synchronization signal (SS) block resource covering the user equipment; and assign the user equipment one or more BRACH preambles for each BRACH resource assigned to the user equipment, excluding the BRACH resource holding beam correspondence with the SS block resource covering the user equipment.

### Claim 7 (depends on 6)

The device of claim 6, wherein the one or more processors further execute the instructions to: transmit one or more of the SS block resources, where each of the SS block resources has a different beam direction.

### Claim 8 (depends on 6)

The device of claim 6, wherein the BRACH resource supports N*(K/(K−1)) user equipment, where N is a number of user equipment and K is a number of BRACH resources with different beams.

### Claim 9 (depends on 6)

The device of claim 6, wherein when the user equipment has more than one SS block resource in use, the base station does not assign a BRACH preamble for the user equipment on the BRACH resources holding beam correspondence with the SS block resources in use.

### Claim 10 (depends on 6)

The device of claim 6, wherein the one or more processors further execute the instructions to: receive a beam failure recovery request (BFRR) from the user equipment, including identification of a different SS block resource as a new candidate beam, upon detection of a beam failure between the base station and the user equipment; and identifying the new candidate beam upon receiving a BRACH preamble assigned for the user equipment at the BRACH resource.