# US 2021/0345279 A1 · Signaling of timing advance (ta) offsets in iab networks

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- Number: US 2021/0345279 A1
- Document ID: US20210345279A1
- Status: Published application
- Kind: A1
- Application number: 17/286,217
- Filed: 2019-10-24
- Published: 2021-11-04
- Earliest claimed: 2018-10-25
- Assignees: Apple Inc.
- Applicants: Apple Inc.
- Inventors: Dawei YING; Geng WU; Lili WEI; Qian LI
- Web page: https://patentgrep.com/patent/US20210345279A1

## CPC

- H04W 56/0045: {compensating for timing error by altering transmission time}
- H04B 7/15: Active relay systems
- H04B 7/15528: {Control of operation parameters of a relay station to exploit the physical medium}
- H04W 56/0055: {determining timing error of reception due to propagation delay}
- H04W 74/0833: Random access procedures, e.g. with 4-step access
- H04W 84/04: Large scale networks; Deep hierarchical networks
- H04W 88/08: Access point devices
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- H04B: TRANSMISSION

## Abstract

Embodiments of an integrated access and backhaul (IAB) node, a User Equipment (UE), and methods of communication are generally described herein. An IAB node may operate as a relay between an IAB donor and a UE. The IAB node may receive, from the IAB donor, first signaling that indicates a first timing advance (TA) offset between the IAB donor and the IAB node. The IAB node may determine a second TA offset between the IAB node and the UE. The second TA offset may be based on a timing difference between a transmission time of a downlink frame transmitted to the UE and a reception time of an uplink frame from the UE. The IAB node may transmit, to the UE, second signaling that indicates the first TA offset and the second TA offset.

## Claims

### Claim at position 1

1-18. (canceled)

### Claim 19

An apparatus, comprising:
at least one processor configured to cause an Integrated Access and Backhaul (IAB) node of an IAB network, the IAB node operating as a relay between an IAB donor of the IAB network and a User Equipment (UE), to:
decode, from the IAB donor, first signaling that indicates a first timing offset for uplink timing calculation;
decode, from the IAB donor, second signaling that indicates a second timing offset;
based on the first timing offset and the second timing offset, determine a transmit timing of the IAB node;
encode a downlink frame for transmission to the UE in accordance with the determined transmit timing.

### Claim 20 (depends on 19)

The apparatus of claim 19, wherein the at least one processor is further configured to:
determine a time difference between transmission and reception of a signal based on the first and second timing offsets to determine the transmission time.

### Claim 21 (depends on 19)

The apparatus of claim 19, wherein the at least one processor is further configured to:
decode the first and second signaling to include:
medium access control (MAC) control elements (CEs).

### Claim 22 (depends on 19)

The apparatus of claim 19, wherein the at least one processor is further configured to:
encode a Timing Advance (TA) signaling to the UE as part of the downlink frame transmission to the UE.

### Claim 23 (depends on 19)

The apparatus of claim 19, wherein the at least one processor is further configured to:
decode an uplink frame from the UE prior to encoding the downlink frame for transmission to the UE.

### Claim 24 (depends on 19)

The apparatus of claim 19, wherein the at least one processor is further configured to:
decode the first timing offset as Timing Advance (TA) timing offset.

### Claim 25 (depends on 23)

The apparatus of claim 23, wherein the at least one processor is further configured to:
decode the uplink frame as part of a random access procedure.

### Claim 26 (depends on 19)

The apparatus of claim 19, wherein the at least one processor is further configured to:
encode the downlink frame as part of a random access response (RAR) message.

### Claim 27 (depends on 19)

The apparatus of claim 19, wherein the first signaling is included in a medium access control (MAC) control element (CE) received from the IAB donor while the IAB node operates in a radio resource control (RRC) connected mode.

### Claim 28 (depends on 19)

The apparatus of claim 19, wherein:
the IAB node operates as a relay between the IAB donor and a plurality of UEs, the at least one processor is further configured to, for each of the UEs of the plurality of UEs:
determine a Timing Advance (TA) offset between the IAB node and the UE; and
encode, for transmission to the UE, signaling that indicates the TA offset between the IAB node and the UE,
wherein the at least one processor is configured to transmit the signaling to each of the UEs to align timing of the IAB node with timing of each UE of the plurality of UEs.

### Claim 29 (depends on 19)

The apparatus of claim 19, wherein:
the IAB node comprises a Mobile Terminating (MT) unit and a Distributed Unit (DU),
the first and second signaling are received at the MT unit from a Distributed Unit (DU) of the IAB donor.

### Claim 30 (depends on 19)

The apparatus of claim 19, wherein:
the at least one processor includes a baseband processor to decode the signaling, and
the apparatus further comprises a transceiver to receive the signaling.

### Claim 31 (depends on 19)

The apparatus of claim 19, wherein the at least one processor is further configured to:
derive the first and second timing offsets differently from the first and second signaling.

### Claim 32 (depends on 19)

The apparatus of claim 19, wherein the at least one processor is further configured to:
decode the first and second signaling as integer indices.

### Claim 33

A non-transitory computer-readable storage medium storing program instructions executable by at least one processor of an Integrated Access and Backhaul (IAB) node of an IAB network, wherein the IAB network comprises an IAB donor and a plurality of IAB nodes to operate as relays between the IAB donor and a plurality of User Equipment (UEs), the program instructions executable to configure the at least one processor to:
decode first signaling that indicates a first timing offset for uplink timing calculation;
decode, from the IAB donor, second signaling that indicates a second timing offset;
determine, based on the first timing offset and the second timing offset, a transmit timing of the IAB node;
encode a downlink frame for transmission to the UE in accordance with the determined transmit timing.

### Claim 34 (depends on 33)

The non-transitory computer-readable storage medium of claim 33, the program instructions further executable to configure the at least one processor to:
decode a frame from the IAB donor, wherein the frame is intended for the TIE for which the other IAB node operates as a relay;
forward the frame to the other IAB node for forwarding to the TIE.

### Claim 35

An apparatus, comprising:
at least one processor configured to cause a user equipment (UE) to:
decode a downlink frame from an Integrated Access and Backhaul (IAB) node of an IAB network, wherein the IAB node is configured to operate as a relay between an IAB donor of the IAB network and the TIE;
encode an uplink frame for transmission to the IAB node;
decode, from the IAB node, signaling that indicates:
a difference between a first timing offset between the IAB donor and the IAB node and a second timing offset between the IAB node and the UE, and
the second timing offset between the IAB node and the UE;
determine a transmit timing of the UE based on the first and second timing offsets;
encode another uplink frame for transmission to the IAB node for forwarding to the IAB donor, the other uplink frame encoded for transmission in accordance with the determined transmit timing.

### Claim 36 (depends on 35)

The apparatus of claim 35, wherein the signaling from the IAB node includes:
medium access control (MAC) control elements (CEs).

### Claim 37 (depends on 35)

The apparatus of claim 35, wherein the at least one processor includes a baseband processor to decode the signaling, and
the apparatus further comprises a transceiver to receive the signaling.

### Claim 38 (depends on 35)

The apparatus of claim 35, wherein the IAB node comprises a Mobile Terminating (MT) unit and a Distributed Unit (DU), and wherein the signaling is received at the MT unit from a Distributed Unit (DU) of the IAB donor.