US-12621814-B2 - Bandwidth part operation in a wireless communication network

US12621814B2US 12621814 B2US12621814 B2US 12621814B2US-12621814-B2

Abstract

A wireless device ( 18 ) is configured for use in a wireless communication network ( 10 ). The wireless device ( 18 ) receives broadcasted system information ( 20 ) for a cell ( 14 ). The broadcasted system information ( 20 ) indicates multiple bandwidth parts ( 16 - 1, 16 - 2 . . . 16 -N) of the cell ( 14 ), where the multiple bandwidth parts ( 16 - 1, 16 - 2, . . . 16 -N) indicated are either multiple downlink bandwidth parts or multiple uplink bandwidth parts. Alternatively or additionally, the broadcasted system information ( 20 ) indicates respective frequency positions of multiple synchronization signal blocks, SSBs, for the cell ( 14 ).

Inventors

Xingqin LIN
Olof Liberg
Helka-Liina Määttänen
Jonas SEDIN

Assignees

TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

Dates

Publication Date: 20260505
Application Date: 20210304

Claims (3)

1 . A method performed by a wireless device configured for use in a wireless communication network, the method comprising, while the wireless device is in a Radio Resource Control (RRC) idle state or an RRC inactive state: receiving broadcasted system information for a cell of the wireless communication network, the broadcasted system information comprising a System Information Block 1 (SIB1) indicating multiple downlink bandwidth parts of the cell that are each usable by the wireless device to camp on the cell; performing signal measurements on one or more downlink signals received in respective ones of the indicated multiple downlink bandwidth parts; selecting one of the indicated multiple downlink bandwidth parts as a selected downlink bandwidth part, the selecting based on comparing the signal measurements for the respective ones of the indicated multiple downlink bandwidth parts; and camping on the cell using the selected downlink bandwidth part by performing a cell selection or reselection to the cell and subsequently monitoring a paging channel in the selected downlink bandwidth part; wherein the indicated multiple downlink bandwidth parts have correspondingly paired uplink bandwidth parts, and wherein the method further comprises selecting the uplink bandwidth part that is correspondingly paired with the selected downlink bandwidth part.
2 . The method of claim 1 , wherein selecting one of the indicated multiple downlink bandwidth parts comprises selecting, from among the respective ones of the indicated multiple downlink bandwidth parts, the indicated downlink bandwidth part corresponding to a highest received signal power, as determined from the signal measurements made for the respective ones of the indicated multiple downlink bandwidth parts.
3 . A wireless device configured for use in a wireless communication network, the wireless device comprising: communication circuitry; and processing circuitry configured to, while the wireless device is in a Radio Resource Control (RRC) idle state or an RRC inactive state: receive, via the communication circuitry, broadcasted system information for a cell of the wireless communication network, the broadcasted system information comprising a System Information Block 1 (SIB1) indicating multiple downlink bandwidth parts of the cell that are each usable by the wireless device to camp on the cell; perform signal measurements on one or more downlink signals received in respective ones of the indicated multiple downlink bandwidth parts; select one of the indicated multiple downlink bandwidth parts as a selected downlink bandwidth part, the selecting based on comparing the signal measurements for the respective ones of the indicated multiple downlink bandwidth parts; and camp on the cell using the selected downlink bandwidth part by performing a cell selection or reselection to the cell and subsequently monitoring a paging channel in the selected downlink bandwidth part; wherein the indicated multiple downlink bandwidth parts have correspondingly paired uplink bandwidth parts, and wherein the method further comprises selecting the uplink bandwidth part that is correspondingly paired with the selected downlink bandwidth part.

Description

TECHNICAL FIELD The present application relates generally to a wireless communication network and relates more particularly to bandwidth part operation in such a network. BACKGROUND In some wireless communication networks, such as those based on New Radio (NR), the receive and/or transmit bandwidth of a wireless device need not be as large as the bandwidth of a cell. Rather, the wireless device can use a receive and/or transmit bandwidth that is just a subset of the total cell bandwidth of the cell. In this regard, a subset of the total cell bandwidth of a cell is referred to herein as a bandwidth part (BWP). Allowing a wireless device to use just a part of the total cell bandwidth in this way creates flexibility in how the total cell bandwidth can be used. However, bandwidth part operation heretofore requires all wireless devices (e.g., in a radio resource control, RRC, idle state) to initially access and camp on the cell using the same BWP. This bottleneck in turn threatens to limit system capacity, especially for non-terrestrial networks (NTNs) whose cells cover large areas. Moreover, while reusing frequencies on a bandwidth part basis may improve signal quality and facilitate mobility management, it complicates data channel transmission and reception. SUMMARY According to some embodiments herein, a radio network node informs a wireless device about multiple bandwidth parts (BWPs) of a cell, e.g., multiple downlink BWPs of the cell or multiple uplink BWPs of the cell. The radio network node may for example broadcast system information indicating the multiple BWPs of the cell. In these and other embodiments, then, the wireless device may be informed about the multiple BWPs even in advance of the wireless device accessing, or camping on, the cell, e.g., from a radio resource control (RRC) idle state or an RRC inactive state. This way, rather than only a single BWP being available to the wireless device for accessing or camping on the cell, multiple BWPs are made available in this regard as options for the wireless device to select between. Some embodiments accordingly control or configure wireless device BWP selection so that at least some wireless devices select different BWPs for accessing or camping on the cell, e.g., from RRC idle or RRC inactive. This distributes loading attributable to access and camping across multiple BWPs of the cell so as to advantageously alleviate bottlenecking and increase system capacity. Such may prove particularly advantageous in embodiments where the cell is in a non-terrestrial network (NTN) or otherwise has a large coverage area. According to other embodiments herein, a radio network node alternatively or additionally informs a wireless device about the respective frequency positions of multiple synchronization signal blocks (SSBs) for a cell. Signaling the respective frequency positions of the multiple SSBs for the cell in this way may advantageously enable adaptive use of BWPs for frequency reuse planning, e.g., based on traffic demand. Indeed, in these and other embodiments, SSBs may be flexibly positioned as needed so that any given BWP may have zero, one, or more SSBs included therein, or even have a fraction of an SSB included therein. Rate matching may then be employed for data channel transmissions, to account for potentially multiple SSBs being positioned within the operating bandwidth of the wireless device, e.g., in the form of a selected BWP from among multiple BWPs. Some embodiments may thereby advantageously enable adaptive use of BWPs for frequency reuse planning, while preserving data channel performance. Generally, then, embodiments herein include a method performed by a wireless device configured for use in a wireless communication network. The method may comprise receiving broadcasted system information for a cell. The broadcasted system information indicates at least one of any one or more of: (i) multiple bandwidth parts of the cell; and (ii) respective frequency positions of multiple synchronization signal blocks (SSBs) for the cell. In embodiments where the broadcasted system information indicates multiple bandwidth parts of the cell, the multiple bandwidth parts indicated may be either multiple downlink bandwidth parts or multiple uplink bandwidth parts. In some embodiments, the multiple bandwidth parts indicated are each usable by the wireless device to access, or camp on, the cell, e.g., in a Radio Resource Control, RRC, idle state or an RRC inactive state. In this case, the method may further comprise selecting, from the multiple bandwidth parts indicated, one or more bandwidth parts to use for accessing, or camping on, the cell. Alternatively or additionally, the method may further comprise accessing, or camping on, the cell using one or more of the multiple bandwidth parts indicated, e.g., from an RRC idle state or an RRC inactive state. Accordingly, in some embodiments, the broadcasted system information indicates the multiple bandwidth part