Cell reselection optimization for non-terrestrial networks

Abstract

According to some embodiments, a method is performed by a wireless device for cell selection or reselection in a non-terrestrial network (NTN). The method comprises obtaining information regarding a store and forward operational mode of one or more of a serving cell of the wireless device and one or more neighbor cells of the wireless device and performing cell selection or reselection based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells.

Description

P112964WO01 PCT APPLICATION 1 of 40Cell Reselection Optimization for Non-Terrestrial NetworksTECHNICAL FIELD

[0001] The present disclosure generally relates to communication networks, and more specifically to cell reselection optimization for non-terrestrial networks (NTNs).BACKGROUND

[0002] The standardization of non-terrestrial network (NTN) technologies continues in Third Generation Partnership Project (3GPP) with two additional work items for New Radio (NR) and Long-Term Evolution (LTE) (RP-234077, New Work Item Description (WID): Non-Terrestrial Networks (NTN) for Internet of Things (loT) Phase 3; RP -234078, New WID: Non-Terrestrial Networks (NTN) for NR Phase 3.TR 38.811, Study on New Radio (NR) to support non-terrestrial networks). The justification for these enhancements is based on the commercial deployments that are currently ongoing. Based on real deployment or deployment plans, further evolution of NR and Intemet-of-things (loT) NTN is required.

[0003] Some of the objectives included in the loT NTN Release 19 WID include support of store and forward (S&F) satellite operation with full eNB as regenerative payload. Thus, some objectives are to define the necessary enhancements into Evolved Universal Terrestrial Radio Access Network (E-UTRAN) (network and user equipment (UE) to support S&F operation for delay-tolerant services and to specify necessary enhancements, e.g. related to SI protocol, especially to address the feeder link switch over as needed.

[0004] An additional objective is to minimize UE impact. Coordination is needed on the detailed requirements (e.g., traffic type, or quality of service (QoS) parameters for S&F), network architecture (e.g., whether consider (partial) core network on satellite), etc.

[0005] The store and forward architecture for NTN involves the use of network nodes as satellites or high-altitude platforms (HAPS) to relay communication signals between terrestrial UE and the core network. This architecture is designed to extend the coverage and capacity of traditional terrestrial networks, particularly in remote or underserved areas.

[0006] The store and forward mechanism enables the NTN to temporarily store incoming data before transmitting the data to the next hop in the network, which could be another relay node (e.g., using inter-satellite links) or the core network itself. This enables the NTN to overcome the inherent latency and intermittent connectivity associated with non-terrestrial communication links.P112964WO01 PCT APPLICATION 2 of 40

[0007] The store and forward architecture is particularly useful in scenarios where the NTN is used to provide connectivity in areas with limited terrestrial infrastructure, such as remote rural or maritime environments. Using this mechanism, the NTN can efficiently manage the transmission of data between UEs and the core network, even in challenging communication conditions, i.e., areas where satellites cannot be connected to ground stations. From a business perspective, this architecture improves ground segment affordability by enabling operation with fewer ground-stations and a more robust operation of the satellite under intermittent feeder link operation. This is specifically well-suited for delay-tolerant loT applications that do not require continuous connectivity.

[0008] Figure 1 is a network diagram illustrating store and forward operation for an NTN payload. The following include some related 3GPP agreements with respect to store and forward. For the uplink / downlink message transmission for mobile originated (MO) messages, the following steps are taken as a baseline for S&F satellite operation (when only eNB is on the satellite). The UE sends uplink data signaling to eNB when service link is available and the eNB stores the data. When feeder link is available, the eNB sends the uplink data / non-access stratum (NAS) signaling to the core network (CN).

[0009] The eNB (same or different) receives the downlink data / NAS signaling from the CN and stores it when feeder link is available (and service link is not available). The eNB (same or different) sends the downlink data / signaling to the UE when service link is available again.

[0010] A store and forward indication may be provided by system information block (SIB). A NAS indication is not needed.

[0011] Legacy UEs may be barred by legacy cellBarred and cellBarredNTN.

[0012] Possible store and forward architectures that may be used as a baseline for discussion include the full CN and split-mobility management entity (MME) payload options. Both single satellite pass and multiple satellite pass scenarios will be considered.

[0013] Both mobile originated (MO) and mobile terminated (MT) data will be considered.

[0014] A UE is informed whether its serving satellite is currently operating in store and forward via system information broadcast.

[0015] Whether legacy UEs will always need to be barred in a store and forward network is not currently considered. If there will be a need for this, mechanisms to bar legacy UEs are already in place and no further impact is expected.

[0016] There will be a way to bar legacy UEs (using legacy cellBarred and / or cellBarredNTN bit) and still allow R19 store and forward capable UEs.P112964WO01 PCT APPLICATION 3 of 40

[0017] The dynamic indication that “the cell is operating in S&F mode” is referred to as “S&F operation” indication.

[0018] If an indication that “the cell is operating in S&F mode” is not provided in an NTN cell, the UE should assume that the NTN cell is operating in real-time mode (i.e., default / normal / ”not-S&F” mode). There should be no distinction between the case where the UE is served by an NTN cell that does not support S&F capability and the case where the UE is served by an NTN cell that does support S&F capability but an indication that “the cell is operating in S&F mode” is not provided.

[0019] An S&F explicit capability indication by the serving cell, conceived as a static indication of whether the S&F capability is supported by a specific satellite / NTN-cell, in addition to the indication that “the cell is operating in S&F mode,” is not needed.

[0020] If the “S&F operation” indication is not broadcast, a Rel-19 UE (regardless of whether supporting S&F) shall follow the legacy barring procedure.

[0021] When present, the “S&F operation” indication has two possible settings: ‘ 1 ’ the cell is operating in S&F mode for all UEs (Rel-19 UEs supporting S&F are allowed to access the cell), and ‘0’ the cell is operating in S&F mode for UEs in Connected mode (which are not required to monitor the “S&F indication”), but idle Rel-19 UEs supporting S&F are barred (Rel-19 UEs not supporting S&F will follow legacy barring procedure).

[0022] Time information may be broadcasted to indicate when the current satellite operation mode will transit from “S&F operation” mode to real-time / normal mode. A R19 UE may use the time information at least to delay some NAS procedures until the feeder link is resumed.

[0023] “S&F operation” indication is provided in SIB 1.

[0024] AS signaling is not needed to indicate the architecture option (Split MME or Full CN).

[0025] A UE configured with a satellite ID list by MME is not prevented from camping on a satellite operating in normal loT NTN mode (i.e., with feeder-link connection) and perform subsequent access and data / signaling communication with that satellite.

[0026] A UE configured with a satellite ID list by MME is not prevented from camping on, attempting to access and / or communicating with a satellite that is not included in the MME-configured satellite list.

[0027] There currently exist certain challenges. For example, a store and forward capable loT NTN UE may camp in one or more loT NTN cell (onboard satellite or managing satellite) that operates S&F (store and forward) service or operates legacy / normal / non-S&F service. ComparedP112964WO01 PCT APPLICATION 4 of 40with normal (non-S&F) operation, S&F operation is intended to only provide a limited service, e.g., lower QoS (e.g., not time critical data), smaller data packet, to the UE.

[0028] The present cell (re)selection mechanism mainly considers received signal strength to guide the choice of a target cell. This may be inefficient when some cells operate in S&F mode and may not provide the same type of services (or be able to meet the same type of traffic demands) as others operating in normal (non-S&F mode).SUMMARY

[0029] As described above, certain challenges currently exist with cell (re)selection for nonterrestrial networks (NTNs). For example, the present cell (re)selection mechanism mainly considers received signal strength to guide the choice of a target cell. This may be inefficient when some cells operate in store and forward (S&F) mode and may not provide the same type of services (or be able to meet the same type of traffic demands) as others operating in normal (non-S&F mode).

[0030] A user equipment (UE) may prefer to perform cell reselection to another Internet of things (loT) NTN cell with normal (non-S&F) operation whenever possible to meet its downlink / uplink transmission demands. Provided the UE may know the operation mode of each of its neighbor cells via system information broadcast, it is desirable to use this knowledge with the cell reselection algorithm to select the best target cell according to the UE traffic profile.

[0031] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. For example, particular embodiments include a S&F capable UE, served by a loT NTN cell (onboard satellite or managing satellite), for managing cell (re)selection scheme with respect to the serving cell that operates S&F (store and forward) mode and neighbor cells that operate in legacy / normal / non-S&F service. Particular embodiments consider one or more factors, conditions, quantities and properties concerning the S&F operation mode or legacy / normal / non-S&F service operation mode that are provided by the target / source loT NTN cell and have an impact on the cell (re)selection procedure and the final choice of target cell for the idle mode mobility event.

[0032] In general, particular embodiments consider one or more conditions related to a satellite operation mode (e.g., S&F mode) in the procedure for cell (re)selection. Based on the information provided to the UE via broadcast or dedicated signaling, the UE may modify the evaluation criteria for its neighbor cells, affecting the final selection of a candidate cell, or even trigger the cell (re)selection evaluation procedure.P112964WO01 PCT APPLICATION 5 of 40

[0033] According to some embodiments, a method is performed by a wireless device for cell selection or reselection in a NTN. The method comprises obtaining information regarding a store and forward operational mode of one or more of a serving cell of the wireless device and one or more neighbor cells of the wireless device and performing cell selection or reselection based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells.

[0034] In particular embodiments, the information regarding store and forward mode of the serving cell and the one or more neighbor cells comprises one or more of: a time remaining in store and forward operation mode; a time remaining until a start of store and forward operation mode; a time remaining in non-store and forward mode; and an indication that a store and forward buffer is above a threshold value.

[0035] In particular embodiments, performing the cell selection or reselection based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells comprises triggering a cell selection or reselection evaluation procedure based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells.

[0036] In particular embodiments, performing the cell selection or reselection based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells comprises prioritizing candidate cells based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells. For example, prioritizing candidate cells based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells may comprise excluding candidate cells based on a store and forward mode of the candidate cell (e.g., excluding candidate cells operating in store and forward mode or about to operate in store in forward mode).

[0037] In particular embodiments, performing the cell selection or reselection is further based on one or more of: an amount of data in an uplink buffer of the wireless device; a quality of service value associated with data to be transmitted or received by the wireless device; and a type of data to be transmitted or received by the wireless device.

[0038] In particular embodiments, obtaining information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells comprises receiving system broadcast information.P112964WO01 PCT APPLICATION 6 of 40

[0039] In particular embodiments, the method further comprises receiving an indication whether to perform cell selection or reselection based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells. Receiving the indication may comprise receiving a connection release message (e.g., RRC Connection Release).

[0040] According to some embodiments, a wireless device comprises processing circuitry operable to perform any of the wireless device methods described above.

[0041] Also disclosed is a computer program product comprising a non-transitory computer readable medium storing computer readable program code, the computer readable program code operable, when executed by processing circuitry to perform any of the methods performed by the wireless device described above.

[0042] According to some embodiments, a method is performed by a network node to assist a wireless device with cell selection or reselection in a NTN. The method comprises obtaining information regarding a store and forward operational mode of one or more of the network node and one or more neighbor cells and transmitting the information regarding a store and forward operational mode of one or more of the network node and one or more neighbor cells to the wireless device. Transmitting the information regarding the store and forward operational mode of one or more of the network node and the one or more neighbor cells may comprise broadcasting system information.

[0043] In particular embodiments, the method further comprises transmitting an indication to the wireless device whether to perform cell selection or reselection based on the information regarding the store and forward operational mode of one or more of the network node and one or more neighbor cells. Transmitting the indication may comprise transmitting a connection release message to the wireless device.

[0044] According to some embodiments, a network node comprises processing circuitry operable to perform any of the network node methods described above.

[0045] Another computer program product comprises a non-transitory computer readable medium storing computer readable program code, the computer readable program code operable, when executed by processing circuitry to perform any of the methods performed by the network node described above.

[0046] Certain embodiments may provide one or more of the following technical advantages. For example, the inclusion of conditions to evaluate S&F operation mode assist the UE in choosing (if available) a neighbor cell that is better suited for its traffic demands. In addition, several of theP112964WO01 PCT APPLICATION 7 of 40criterion included herein help reduce a potential ping-pong effect between cells that do support normal / non-S&F mode and S&F mode, which may have a detrimental effect on UE battery due to the need to constantly send a new Attach or tracking area update (TAU( message as well as network load and coordination issues caused by the presence of a UE context in both a split mobility management entity (MME) (with part on the satellite) and a ground MME.BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The present disclosure may be best understood by way of example with reference to the following description and accompanying drawings that are used to illustrate embodiments of the present disclosure. In the drawings:Figure 1 is a network diagram illustrating store and forward operation for a non-terrestrial network (NTN) payload;Figure 2 shows an example of a communication system, according to certain embodiments; Figure 3 shows a user equipment (UE), according to certain embodiments;Figure 4 shows a network node, according to certain embodiments;Figure 5 is a flowchart illustrating an example method in a wireless device, according to certain embodiments; andFigure 6 is a flowchart illustrating an example method in a network node, according to certain embodiments.DETAILED DESCRIPTION

[0048] As described above, certain challenges currently exist with cell (re)selection for nonterrestrial networks (NTNs). For example, the present cell (re)selection mechanism mainly considers received signal strength to guide the choice of a target cell. This may be inefficient when some cells operate in store and forward (S&F) mode and may not provide the same type of services (or be able to meet the same type of traffic demands) as others operating in normal (non-S&F mode). A user equipment (UE) may prefer to perform cell reselection to another Internet of things (loT) NTN cell with normal (non-S&F) operation whenever possible to meet its downlink / uplink transmission demands. Provided the UE may know the operation mode of each of its neighbor cells via system information broadcast, it is desirable to use this knowledge with the cell reselection algorithm to select the best target cell according to the UE traffic profile.

[0049] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. For example, particular embodiments include a S&F capable UE, served by aP112964WO01 PCT APPLICATION 8 of 40loT NTN cell (onboard satellite or managing satellite), for managing cell (re)selection scheme with respect to the serving cell that operates S&F (store and forward) mode and neighbor cells that operate in legacy / normal / non-S&F service.

[0050] Particular embodiments are described more fully with reference to the accompanying drawings. Embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0051] The embodiments outlined below are described mainly in terms of Long-Term Evolution (LTE) based (including (loT)) NTNs, but they are equally applicable in an NTN based on New Radio (NR) (including loT) technology.

[0052] The term “network” is used herein to refer to a network node, which typically will be an eNB (e.g., in an LTE based NTN), but which may also be a gNB (e.g., in a New Radio (NR) based NTN), or a base station or an access point in another type of network, or any other network node with the ability to directly or indirectly communicate with a UE.

[0053] The terms “idle mode,” “RRC IDLE state,” or “RRC CONNECTED mode” are used interchangeably herein.

[0054] The terms satellite footprint information and satellite assistance information (SAI) refer to the minimum necessary information that enables a UE to determine the size and location on Earth of an NTN cell. For earth fixed cells, the information includes, but is not limited to, cell radius and cell reference location. For earth-moving cells, the information includes, but is not limited to, satellite ephemeris, minimum elevation angles, as described in SIB32, cell radius and / or cell reference location offset with respect to the satellite’s nadir for beams that are not evenly distributed around nadir and might have a certain inclination.

[0055] Herein, the value oft-service-rl7 is sometimes referred as “remaining service time” or “current cell stop serving time.” This parameter informs the UE when the satellite (normally operating in a low earth orbit (LEO) or medium earth orbit (MEO)) that is serving the cell to which the UE is connected will stop serving the area due to its movement.

[0056] In the examples, the greater than condition, “>”, may be replaced by greater than or equal to, “>”.

[0057] A satellite operating in store and forward mode (or non-store and forward mode) means that the satellite payload (i.e., in this context the communications related equipment placed in the satellite) operates in store and forward mode (or non-store and forward mode). Whether a satellite operates in store and forward mode (or non-store and forward mode), and whether a satelliteP112964WO01 PCT APPLICATION 9 of 40payload operates in store and forward mode (or non-store and forward mode) are considered to be equivalent concepts.

[0058] A satellite or NTN payload operating in store and forward mode is associated herein with a lack of end-to-end connectivity. A limitation with this association is that it only indicates the current satellite's mode of operation in the NTN radio access network (RAN), while makes no guarantees that the other end of a communication is available without store and forward at that end. Depending on the scenario, store and forward may still be applied to the communication in another part of the network on the path to the remote endpoint, e.g. in another satellite payload or in a network node with intermittent connectivity to a satellite payload.

[0059] The terms “store and forward operation mode” (“S&F operation mode”) and “store and forward mode” (“S&F mode”) are regarded as equivalent. Similarly, the terms “non-store and forward operation mode” (“non-S&F operation mode”) and “non-store and forward mode” (“non-S&F mode”) are regarded as equivalent.

[0060] There are two main deployment principles for NTN: quasi-earth-fixed cells and earthmoving cells. These deployment principles are also referred to by other names. The quasi-earth-fixed cells deployment principle is also referred to as quasi-earth-fixed beams. The earth-moving cells deployment principle is also referred to as earth-moving beams, or shorter, moving or and moving beams.

[0061] Particular embodiments may be described with respect to the following reference scenario. A UE in RRC_IDLE / RRC_INACTIVE is camping in an NTN cell served by a satellite that currently operates in S&F mode or will soon start operating in S&F mode. The UE is aware when the serving satellite starts or stops the S&F operation mode via parameters provided in system information broadcast. Similarly, the UE is aware of the operation mode of its neighbor cells (provided they are served by different satellites than the serving cell), i.e. whether they are or not presently operating in S&F mode.

[0062] Particular embodiments consider one or more conditions related to the satellite’s operation mode (e.g., S&F mode) in the cell reselection algorithm, i.e., ranking of neighbor cells of equal or different priority, and the cell reselection triggers. Based on the information provided to the UE via broadcast or dedicated signaling, the UE may modify the evaluation criteria for its neighbor cells, affecting the final selection of a candidate cell, or initiate the cell reselection evaluation procedure.

[0063] Some embodiments include signaling of neighbor cell properties related to operation mode. In some embodiments, a UE receives information about the neighbor cell properties relatedP112964WO01 PCT APPLICATION 10 of 40to the operation mode, e.g. S&F operation mode or non-S&F operation mode, and other neighbor cell information relevant for the cell reselection in the embodiments below from transmissions in the serving cell, e.g. broadcast system information (SI) in the serving cell.

[0064] In some embodiments, the UE receives information about the neighbor cell properties related to the operation mode, e.g. S&F operation mode or non-S&F operation mode, and other neighbor cell information relevant for the cell reselection in the embodiments below, from transmissions in the respective neighbor cells, e.g. broadcast system information (SI) in the neighbor cells.

[0065] In some embodiments, the UE receives some information - or at least part of the information - about the neighbor cell properties related to the operation mode, e.g. S&F operation mode or non-S&F operation mode, and other neighbor cell information relevant for the cell reselection in the embodiments below, from transmissions in the serving cell, e.g. broadcast system information (SI) in the serving cell, and receives some information - or at least part of the information - about the neighbor cell properties related to the operation mode, e.g. S&F operation mode or non-S&F operation mode, and other neighbor cell information relevant for the cell reselection in the embodiments below, from transmissions in the respective neighbor cells, e.g. broadcast system information (SI) in the neighbor cells.

[0066] Factors, quantities and properties impacting the cell reselection algorithm include the following.• Operation mode, e.g. S&F mode or non-S&F modeo For the serving cello For the respective neighbor cells• Decision factors based on time:o Remaining time in S&F operation mode■ For the serving cell■ For the respective neighbor cellso Remaining time until the start of S&F operation mode■ For the serving cell■ For the respective neighbor cellso Remaining time in non-S&F operation mode■ For the serving cell■ For the respective neighbor cellso Remaining time until the cell stops serving the areaP112964WO01 PCT APPLICATION 11 of 40■ For the serving cell■ For the respective neighbor cells• Decision factors based on uplink (UL) data buffer:o Data available in the UE’s UL buffer (medium access control (MAC) layer) / transport buffer size (TBS)o A notification or indication from the serving cell that the buffer for storing UL data in S&F mode is fullo A notification or indication from the serving cell that the buffer for storing UL data in S&F mode is close to being full (e.g. X% of the buffer capacity is used, X% of the buffer capacity is still unused, or X bytes / kilobytes / megabytes / gigabytes of the buffer capacity are still unused) o A notification or indication from a neighbor cell that the buffer for storing UL data in S&F mode is fullo A notification or indication from a neighbor cell that the buffer for storing UL data in S&F mode is close to being full (e.g. X% of the buffer capacity is used, X% of the buffer capacity is still unused, or X bytes / kilobytes / megabytes / gigabytes of the buffer capacity are still unused) o A notification or indication from the serving cell that the buffer for storing UL data in S&F mode is full in a certain neighbor cello A notification or indication from the serving cell that the buffer for storing UL data in S&F mode is close to being full (e.g. X% of the buffer capacity is used, X% of the buffer capacity is still unused, or X bytes / kilobytes / megabytes / gigabytes of the buffer capacity are still unused) in a certain neighbor cell• Decision factors based on traffic demands and quality of service (QoS):o QoS typically required or used by the UE or expected to be required or used by the UE■ This may be configured in the UE or hardcoded in the UE implementation, or■ the UE may determine from experience of historical, previous or recent communication / traffico Typical type of traffic / communication to / from the UEP112964WO01 PCT APPLICATION 12 of 40■ This may be configured in the UE or hardcoded in the UE implementation, or■ the UE may determine from experience of historical, previous or recent communication / traffico Typical properties of traffic / communication to / from the UE■ This may be configured in the UE or hardcoded in the UE implementation, or■ the UE may determine from experience of historical, previous or recent communication / traffico Expected type of traffic / communication to / from the UE■ This may be configured in the UE or hardcoded in the UE implementation, or■ the UE may determine from experience of historical, previous or recent communication / traffico Expected properties of traffic / communication to / from the UE■ This may be configured in the UE or hardcoded in the UE implementation, or■ the UE may determine from experience of historical, previous or recent communication / traffic

[0067] The factors above may be used to impact the cell reselection algorithm and / or the cell ranking algorithm or may be part of the cell reselection algorithm and / or the cell ranking algorithm. To this end, the factors above may be used, e.g. to create conditions, ranking criteria or quantities on which to base the cell ranking.

[0068] Some embodiments include changes to the cell reselection algorithm. One or more of the factors described above may be used in various ways in the cell reselection algorithm, i.e., the cell ranking criteria. Conditions, ranking criteria or ranking related quantities derived from these factors may be combined with a channel quality condition. The channel quality may be measured in terms of reference signal receive power (RSRP), reference signal receive quality (RSRQ), signal to interference and noise ratio (SINR), signal to noise ratio (SNR), reference signal strength indicator (RSSI), pathloss, or any combination thereof. For example, among the neighbor cells with the same priority fulfilling the suitability criterion S (see section 5.2.3.2 in TS 38.304) with aP112964WO01 PCT APPLICATION 13 of 40sustained RSRP > QpsRP-thresh during a specified time T, the UE performs one or more of the following actions:The UE ranks the cells in order of:o The inverse of the remaining time in S&F mode.o Remaining time until the start of S&F mode.The UE excludes from the ranking those cells that operate in S&F mode.The UE only includes in the ranking those cells for which a remaining time until the start of S&F mode is above a certain threshold.The UE excludes from the ranking those cells for which the time remaining in non-S&F mode or the time remaining until the cell stops serving the area is below a certain threshold.The UE excludes from the ranking those cells for which a certain one or certain ones of the factors described above is / are not above a threshold.The UE excludes from the ranking those cells which for a certain one, or certain ones, of the factors described above is / are below a threshold with respect to the cell that is the best regarding the certain factor(s).The UE applies a temporary offset proportional to the serving cell’s remaining time in non-S&F operation mode (or computed as a function of one or more of the factors described above).o R = ki x Texp+ ki x Qceii, with R being the rank measure and higher rank measure means more favorable cell. In this expression, Texp is one of the time-based decision factors in the evaluated cell, Qceii is the evaluated cell’s channel quality in terms of RSRP, RSRQ, SINR, SNR or RSSI, and ki and k are configurable constants > 0. (Qceii may also be the pathloss in the evaluated cell and if this is the case, then ki may be a constant < 0).

[0069] After considering the previous conditions to rank the available neighbor cells, the UE follows legacy procedures to perform cell reselection to the highest ranked cell.P112964WO01 PCT APPLICATION 14 of 40

[0070] In some embodiments, the network provides the UE with an indication (e.g., a flag in system information broadcast or RRCConnectionRelease message), and based on the indication the UE performs cell reselection to the cell that is not currently operating in S&F mode and has the highest expected remaining time until the start of the S&F operation mode or until the end of the cell’s service time (e.g., until the cell disappears as indicated by t-Service), whichever happens first. In a variation, the network provides, in addition, a value or value range of the parameter R, see section 5.2.4.63GPP TS 38.304 version 18.4.0, to assist the UE innarrowing down the number of cells to evaluate with respect to the highest expected remaining time until the start of the S&F operation mode (or until the end of the cell’s service time).

[0071] In some embodiments, the UE may temporarily consider a candidate cell that complies with one or more of the decision factors described above (e.g., the cell does not presently operate in S&F, or has higher expected remaining time until the start of the S&F operation mode compared to the serving cell or other neighbor cells) as higher priority than the serving cell if the serving cell does not fulfil the one or more conditions (e.g., the UE may assign the highest priority number), regardless the information provided via system information broadcast, and perform the cell reselection procedure to higher priority cells according to the clause 5.2.4.5 in 3GPP TS 38.304 version 18.4.0.

[0072] In some embodiments, the network, e.g. the eNB in the UE’s serving cell, indicates in the broadcast information whether the UE should, or is allowed to, take a certain one of the factors described above, or certain ones of the factors described above, into account in the cell reselection determination.

[0073] In some embodiments, the network, e.g. the eNB in the UE’s serving cell, indicates in a message used to release the UE from a connected state to an idle state (e.g., from RRC-CONNECTED state to RRC_IDLE state), e.g. an RRCConnectionRelease message, whether the UE should, or is allowed to, take a certain one of the factors described above, or certain ones of the factors described above, into account in the cell reselection determination.

[0074] In some embodiments, the regular cell reselection algorithm is used as long as the UE’s serving cell is operating in non-S&F operation mode and the remaining time in non-S&F operation mode is greater than a threshold time Threshold. That is, none of the modifications of the regular cell reselection algorithm described herein are applied unless the UE’s serving cell is operating in S&F operation mode or will switch from non-S&F operation mode to S&F operation mode in less than a time Tt res oia. In a variation of these embodiments, the condition for applying the modification(s) of the cell reselection algorithm applies only to a subset of the algorithms that may be applied,P112964WO01 PCT APPLICATION 15 of 40while other cell reselection modifications may be applied irrespective of the current operation mode of the UE’s serving cell.

[0075] In some embodiments, the regular cell reselection algorithm is used as long as the UE’s serving cell is operating in non-S&F operation mode and the remaining time until the cell will switch to S&F operation mode, or the cell stops serving the area, is greater than a threshold time Threshold. That is, the modifications of the regular cell reselection algorithm described herein are not applied unless the UE’s serving cell is operating in S&F operation mode or will switch from non-S&F operation mode to S&F operation mode in less than a time Threshold. In a variation of these embodiments, the condition for applying the modification(s) of the cell reselection algorithm applies only to a subset of the algorithms that may be applied, while other cell reselection modifications may be applied irrespective of the current operation mode of the UE’s serving cell.

[0076] In some embodiments, the different factors, or certain ones of the factors, described above may be accounted for one at a time (or a group at a time) in a priority order. For example, cells are first compared and / or ranked taking a first factor into account, and if this provides a clear result (e.g., one cell stands out as clearly better than the rest), then the cell ranking and choice of cell may end there, whereas if the two or more best cells differ less than Roffset from each other in ranking value after the first round of cell comparison / ranking, then the evaluation may continue with a second round involving the best cells, taking one or more other factor(s) into account, to determine which ones of the best cells from the first round that should be selected (and so on if further rounds are needed, taking even further factors into account). This scheme may be complemented with a configured or specified (in a standard) maximum number of cells that “qualify” from one round to the next. The priority order of the factors may be specified in a standard, configured by the network (e.g., in broadcast system information or in an RRCConnectionRelease message), or determined by the UE (e.g., based on UE implementation and / or the current circumstances).

[0077] In some embodiments, there may be multiple cell reselection algorithms, e.g. multiple algorithms with different modifications of the regular cell reselection algorithm, and which of the algorithms a UE uses may depend on the circumstances, e.g. on the factors described above. This choice of algorithm may be a choice made by the UE itself (e.g., based on UE implementation), or may be stipulated or impacted (e.g., biased) by the network, e.g. in broadcast system information. As an example, the expected properties of the UE’s expected traffic / communication may impact the selection of cell reselection algorithm and / or may impact quantities produced as output or intermediate steps of the algorithm, such as offset(s) or ranking value(s).P112964WO01 PCT APPLICATION 16 of 40

[0078] For example, if the UE’s expected traffic / communication is delay tolerant, e.g. more or less insensitive to the delays incurred by the S&F operation mode, then the UE may use the regular (unmodified) cell reselection algorithm even when the UE’s serving cell is operating in S&F operation mode, or a modified version of the cell reselection algorithm may be further modified so that the offset(s) produced to bias the cell ranking in favor of neighbor cells operating in non-S&F operation mode become(s) smaller or their ranking value(s) become(s) lower. On the other hand, if the UE’s expected traffic is delay sensitive, or less delay insensitive, cells operating in S&F operation mode should preferably be avoided, and thus a higher “cost” for reselecting to a cell operating in non-S&F mode may be tolerated / accepted, e.g. a larger decrease in radio channel quality.

[0079] Some embodiments consider requirements for emergency communication. There may be some cases in which a UE requires the support Internet Protocol (IP) multimedia subsystem (IMS) emergency services in the serving cell. For those cases, when the serving satellite changes its operation mode to S&F, which is informed to the UE via system information broadcast, and the field ims-EmergencySupport in SIB1 is disabled / not enabled, the UE shall perform cell selection / reselection to a suitable cell that supports emergency calls.

[0080] Some embodiments include considerations for earth moving cells. The previous embodiments may be applied to earth moving cell NTN deployments. In these scenarios, the (cell reselection) evaluation conditions and ranking may also need to consider variables such as the satellite speed, satellite trajectory, UE location, UE distance to cell boundary, or remaining service time in the UE location. In contrast to quasi-earth fixed cells, these quantities may not be present in system information broadcast but need to be calculated (or derived) by the UE. However, a few extra considerations may be necessary.

[0081] In some embodiments, the above-mentioned decision factors are combined with the UE’s location with respect to a reference cell center. The reference cell center may be the same as the reference satellite beam center, or it may be a center of a cell formed by several satellite beams. In the former case, the cell center may be provided via system information broadcast. In the latter case, the cell center may be separately signaled to the UE by dedicated RRC signaling or dedicated NAS signaling. In addition to the changes previously mentioned above, the UE may use this criterion to rank the cells from closer to farthest away from the present UE location.

[0082] In some embodiments, the above-mentioned decision factors are combined with the UE’s expected remaining service time (Tex-service-moving) in the cell and / or neighbor cells, which depends on the UE’s location and the satellite assistance information (e.g., speed, referenceP112964WO01 PCT APPLICATION 17 of 40location and radius). A threshold parameter Tthres oid-movmg may be provided via system information broadcast or hardcoded in the specification. The UE uses its own location and the satellite assistance information to calculate the expected remaining service time (Texp-service-moving) in the present cell and / or neighbor cells. The UE excludes from the cell reselection ranking all the neighbor cells whose expected remaining service time is lower than the provided threshold. In other words, the UE excludes the cells given Tex -service-movmg<Tthreshoid-movmg for that specific neighbor cell.

[0083] Figure 2 shows an example of a communication system 100 in accordance with some embodiments. In the example, the communication system 100 includes a telecommunication network 102 that includes an access network 104, such as a radio access network (RAN), and a core network 106, which includes one or more core network nodes 108. The access network 104 includes one or more access network nodes, such as network nodes 110a and 110b (one or more of which may be generally referred to as network nodes 110), or any other similar 3rd Generation Partnership Project (3GPP) access node or non-3GPP access point. The network nodes 110 facilitate direct or indirect connection of user equipment (UE), such as by connecting UEs 112a, 112b, 112c, and 112d (one or more of which may be generally referred to as UEs 112) to the core network 106 over one or more wireless connections.

[0084] Example wireless communications over a wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 100 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that may facilitate or participate in the communication of data and / or signals whether via wired or wireless connections. The communication system 100 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0085] The UEs 112 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with the network nodes 110 and other communication devices. Similarly, the network nodes 110 are arranged, capable, configured, and / or operable to communicate directly or indirectly with the UEs 112 and / or with other network nodes or equipment in the telecommunication network 102 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in the telecommunication network 102.P112964WO01 PCT APPLICATION 18 of 40

[0086] In the depicted example, the core network 106 connects the network nodes 110 to one or more hosts, such as host 116. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 106 includes one more core network nodes (e.g., core network node 108) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 108. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0087] The host 116 may be under the ownership or control of a service provider other than an operator or provider of the access network 104 and / or the telecommunication network 102 and may be operated by the service provider or on behalf of the service provider. The host 116 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio / video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0088] As a whole, the communication system 100 of Figure 2 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and / or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and / or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.P112964WO01 PCT APPLICATION 19 of 40

[0089] In some examples, the telecommunication network 102 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunications network 102 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 102. For example, the telecommunications network 102 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and / or Massive Machine Type Communication (mMTC)ZMassive loT services to yet further UEs.

[0090] In some examples, the UEs 112 are configured to transmit and / or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 104 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 104. Additionally, a UE may be configured for operating in single- or multi-RAT or multi -standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

[0091] In the example, the hub 114 communicates with the access network 104 to facilitate indirect communication between one or more UEs (e.g., UE 112c and / or 112d) and network nodes (e.g., network node 110b). In some examples, the hub 114 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 114 may be a broadband router enabling access to the core network 106 for the UEs. As another example, the hub 114 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 110, or by executable code, script, process, or other instructions in the hub 114. As another example, the hub 114 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 114 may be a content source . For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, the hub 114 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 114 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub 114 acts as a proxy server or orchestrator for the UEs, in particular in if one or more of the UEs are low energy loT devices.

[0092] The hub 114 may have a constant / persistent or intermittent connection to the network node 110b. The hub 114 may also allow for a different communication scheme and / or scheduleP112964WO01 PCT APPLICATION 20 of 40between the hub 114 and UEs (e.g., UE 112c and / or 112d), and between the hub 114 and the core network 106. In other examples, the hub 114 is connected to the core network 106 and / or one or more UEs via a wired connection. Moreover, the hub 114 may be configured to connect to an M2M service provider over the access network 104 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 110 while still connected via the hub 114 via a wired or wireless connection. In some embodiments, the hub 114 may be a dedicated hub - that is, a hub whose primary function is to route communications to / from the UEs from / to the network node 110b. In other embodiments, the hub 114 may be a nondedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 110b, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0093] Figure 3 shows a UE 200 in accordance with some embodiments. As used herein, a UE refers to a device capable, configured, arranged and / or operable to communicate wirelessly with network nodes and / or other UEs. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, gaming console or device, music storage device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), smart device, wireless customer-premise equipment (CPE), vehicle-mounted or vehicle embedded / integrated wireless device, etc. Other examples include any UE identified by the 3rd Generation Partnership Project (3GPP), including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0094] A UE may support device-to-device (D2D) communication, for example by implementing a 3 GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle-to-everything (V2X) . In other examples, a UE may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0095] The UE 200 includes processing circuitry 202 that is operatively coupled via a bus 204 to an input / output interface 206, a power source 208, a memory 210, a communication interfaceP112964WO01 PCT APPLICATION 21 of 40212, and / or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Figure 2. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0096] The processing circuitry 202 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in the memory 210. The processing circuitry 202 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general-purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 202 may include multiple central processing units (CPUs).

[0097] In the example, the input / output interface 206 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and / or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into the UE 200. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0098] In some embodiments, the power source 208 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. The power source 208 may further include power circuitry for delivering power from the power source 208 itself, and / or an external power source, to the various parts of the UE 200 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of the power source 208. Power circuitry may perform any formatting, converting, or other modification to the power from theP112964WO01 PCT APPLICATION 22 of 40power source 208 to make the power suitable for the respective components of the UE 200 to which power is supplied.

[0099] The memory 210 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 210 includes one or more application programs 214, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 216. The memory 210 may store, for use by the UE 200, any of a variety of various operating systems or combinations of operating systems.

[0100] The memory 210 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and / or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ The memory 210 may allow the UE 200 to access instructions, application programs and the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in the memory 210, which may be or comprise a device-readable storage medium.

[0101] The processing circuitry 202 may be configured to communicate with an access network or other network using the communication interface 212. The communication interface 212 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 222. The communication interface 212 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 218 and / or a receiver 220 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 218 and receiver 220 may be coupled to one or moreP112964WO01 PCT APPLICATION 23 of 40antennas (e.g., antenna 222) and may share circuit components, software or firmware, or alternatively be implemented separately.

[0102] In the illustrated embodiment, communication functions of the communication interface 212 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented in according to one or more communication protocols and / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol / intemet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0103] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 212, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

[0104] As another example, a UE comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

[0105] A UE, when in the form of an Internet of Things (loT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non -limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door / window sensor, a flood / moisture sensor, an electrical door lock, a connected doorbell, an air conditioningP112964WO01 PCT APPLICATION 24 of 40system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a head-mounted display for Augmented Reality (AR) or Virtual Reality (VR), a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or itemtracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an loT device comprises circuitry and / or software in dependence of the intended application of the loT device in addition to other components as described in relation to the UE 200 shown in Figure 2.

[0106] As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and / or measurements and transmits the results of such monitoring and / or measurements to another UE and / or a network node. The UE may in this case be an M2M device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation.

[0107] In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g. by controlling an actuator) to increase or decrease the drone’s speed. The first and / or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

[0108] Figure 4 shows a network node 300 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged and / or operable to communicate directly or indirectly with a UE and / or with other network nodes or equipment, in a telecommunication network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NRNodeBs (gNBs)).

[0109] Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount ofP112964WO01 PCT APPLICATION 25 of 40coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units and / or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

[0110] Other examples of network nodes include multiple transmission point (multi -TRP) 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell / multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and / or Minimization of Drive Tests (MDTs).[oni] The network node 300 includes a processing circuitry 302, a memory 304, a communication interface 306, and a power source 308. The network node 300 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 300 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 300 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 304 for different RATs) and some components may be reused (e.g., a same antenna 310 may be shared by different RATs). The network node 300 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 300, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 300.

[0112] The processing circuitry 302 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor,P112964WO01 PCT APPLICATION 26 of 40application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and / or encoded logic operable to provide, either alone or in conjunction with other network node 300 components, such as the memory 304, to provide network node 300 functionality.

[0113] In some embodiments, the processing circuitry 302 includes a system on a chip (SOC).In some embodiments, the processing circuitry 302 includes one or more of radio frequency (RF) transceiver circuitry 312 and baseband processing circuitry 314. In some embodiments, the radio frequency (RF) transceiver circuitry 312 and the baseband processing circuitry 314 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 312 and baseband processing circuitry 314 may be on the same chip or set of chips, boards, or units.

[0114] The memory 304 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device-readable and / or computer-executable memory devices that store information, data, and / or instructions that may be used by the processing circuitry 302. The memory 304 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions capable of being executed by the processing circuitry 302 and utilized by the network node 300. The memory 304 may be used to store any calculations made by the processing circuitry 302 and / or any data received via the communication interface 306. In some embodiments, the processing circuitry 302 and memory 304 is integrated.

[0115] The communication interface 306 is used in wired or wireless communication of signaling and / or data between a network node, access network, and / or UE. As illustrated, the communication interface 306 comprises port(s) / terminal(s) 316 to send and receive data, for example to and from a network over a wired connection. The communication interface 306 also includes radio front-end circuitry 318 that may be coupled to, or in certain embodiments a part of, the antenna 310. Radio front-end circuitry 318 comprises filters 320 and amplifiers 322. The radio front-end circuitry 318 may be connected to an antenna 310 and processing circuitry 302. The radio front-end circuitry may be configured to condition signals communicated between antenna 310 and processing circuitry 302. The radio front-end circuitry 318 may receive digital data thatP112964WO01 PCT APPLICATION 27 of 40is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 318 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 320 and / or amplifiers 322. The radio signal may then be transmitted via the antenna 310. Similarly, when receiving data, the antenna 310 may collect radio signals which are then converted into digital data by the radio front-end circuitry 318. The digital data may be passed to the processing circuitry 302. In other embodiments, the communication interface may comprise different components and / or different combinations of components.

[0116] In certain alternative embodiments, the network node 300 does not include separate radio front-end circuitry 318, instead, the processing circuitry 302 includes radio front-end circuitry and is connected to the antenna 310. Similarly, in some embodiments, all or some of the RF transceiver circuitry 312 is part of the communication interface 306. In still other embodiments, the communication interface 306 includes one or more ports or terminals 316, the radio front-end circuitry 318, and the RF transceiver circuitry 312, as part of a radio unit (not shown), and the communication interface 306 communicates with the baseband processing circuitry 314, which is part of a digital unit (not shown).

[0117] The antenna 310 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 310 may be coupled to the radio front-end circuitry 318 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 310 is separate from the network node 300 and connectable to the network node 300 through an interface or port.

[0118] The antenna 310, communication interface 306, and / or the processing circuitry 302 may be configured to perform any receiving operations and / or certain obtaining operations described herein as being performed by the network node. Any information, data and / or signals may be received from a UE, another network node and / or any other network equipment. Similarly, the antenna 310, the communication interface 306, and / or the processing circuitry 302 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and / or signals may be transmitted to a UE, another network node and / or any other network equipment.

[0119] The power source 308 provides power to the various components of network node 300 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 308 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 300 with power forP112964WO01 PCT APPLICATION 28 of 40performing the functionality described herein. For example, the network node 300 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 308. As a further example, the power source 308 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

[0120] Embodiments of the network node 300 may include additional components beyond those shown in Figure 4 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and / or any functionality necessary to support the subject matter described herein. For example, the network node 300 may include user interface equipment to allow input of information into the network node 300 and to allow output of information from the network node 300. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 300.

[0121] In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored on in memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer-readable storage medium. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry without executing instructions stored on a separate or discrete device-readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a non-transitory computer-readable storage medium or not, the processing circuitry can be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processing circuitry alone or to other components of the computing device, but are enjoyed by the computing device as a whole, and / or by end users and a wireless network generally.

[0122] FIGURE 5 is a flowchart illustrating an example method 500 in a wireless device, according to certain embodiments. In particular embodiments, one or more steps of FIGURE 5 may be performed by UE 200 described with respect to FIGURE 3. The wireless device is capable of operating in an NTN.

[0123] The method 500 may begin at step 512, where the wireless device (e.g., UE 200) obtains information regarding a store and forward operational mode of one or more of a serving cell of the wireless device and one or more neighbor cells of the wireless device.P112964WO01 PCT APPLICATION 29 of 40

[0124] For example, the wireless device may obtain information regarding a store and forward operational mode of its serving cell. The wireless device may obtain information regarding a store and forward operational mode of one or more neighbor cells. The wireless device may obtain information regarding a store and forward operational mode for its serving cell and one or more neighbor cells.

[0125] In particular embodiments, obtaining information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells comprises receiving system broadcast information. The wireless device may receive information regarding the store and forward operational mode of the serving cell and one or more neighbor cells all from the serving cell, or the wireless device may receive information regarding the store and forward operational mode of the serving cell from the serving cell and the wireless device may receive information regarding the store and forward operational mode of one or more neighbor cells from the one or more neighbor cells.

[0126] In particular embodiments, the wireless device may obtain information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells according to any of the embodiments and examples described herein.

[0127] In particular embodiments, the information regarding store and forward mode of the serving cell and the one or more neighbor cells comprises one or more of: a time remaining in store and forward operation mode; a time remaining until a start of store and forward operation mode; a time remaining in non-store and forward mode; and an indication that a store and forward buffer is above a threshold value.

[0128] In particular embodiments, the information regarding store and forward mode of the serving cell and the one or more neighbor cells comprises any of the information described with respect to any of the embodiments and examples described herein.

[0129] At step 514, the wireless device may receive an indication whether to perform cell selection or reselection based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells. As one example, receiving the indication may comprise receiving a connection release message (e.g., RRC Connection Release). In this example, the wireless device receives the indication when entering an idle / inactive mode and thus has the information available when time to perform cell selection or reselection.

[0130] At step 516, the wireless device performs cell selection or reselection based on the obtained information regarding the store and forward operational mode of one or more of theP112964WO01 PCT APPLICATION 30 of 40serving cell and one or more neighbor cells. For example, in addition to the conventional criteria for performing cell selection or reselection (e.g., reference signal measurements and thresholds), the wireless device also considers information regarding the store and forward operational mode of the serving cell and / or of neighbor cells. Thus, the selection or reselection may also be based on a time domain parameter associated with, e.g., how long until the start or end of a store and forward operational mode.

[0131] In particular embodiments, performing the cell selection or reselection based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells comprises triggering a cell selection or reselection evaluation procedure based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells. For example, the wireless device may start performing measurements for cell selection or reselection based on the store and forward operational mode (e.g., how much time is left in store and forward mode, how much time is left until entering store and forward mode, etc.) of one or more of the serving cell and one or more neighbor cells. This may result in the wireless device performing cell selection or reselection earlier than if only evaluating conventional criteria. In particular embodiments, the wireless device may trigger a cell selection or reselection evaluation procedure according to any of the embodiments and examples described herein.

[0132] In particular embodiments, performing the cell selection or reselection based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells comprises prioritizing candidate cells based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells. For example, prioritizing candidate cells based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells may comprise excluding candidate cells based on a store and forward mode of the candidate cell (e.g., excluding candidate cells operating in store and forward mode or about to operate in store in forward mode). In particular embodiments, the store and forward mode information is used in conjunction with conventional criteria (e.g., signal strength) to adjust a priority value up or down based on a time domain value associated with the store and forward operation of the candidate cell.

[0133] In particular embodiments, the wireless device may prioritize candidate cells according to any of the embodiments and examples described herein.P112964WO01 PCT APPLICATION 31 of 40

[0134] In particular embodiments, performing the cell selection or reselection is further based on one or more of: an amount of data in an uplink buffer of the wireless device; a quality of service value associated with data to be transmitted or received by the wireless device; and a type of data to be transmitted or received by the wireless device. In particular embodiments, the wireless device may perform the cell selection or reselection according to any of the embodiments and examples described herein.

[0135] Modifications, additions, or omissions may be made to method 500 of FIGURE 5. Additionally, one or more steps in the method of FIGURE 5 may be performed in parallel or in any suitable order.

[0136] FIGURE 6 is a flowchart illustrating an example method 600 in a network node, according to certain embodiments. In particular embodiments, one or more steps of FIGURE 6 may be performed by network node 300 described with respect to FIGURE 4. The network node is operable to assist a wireless device (e.g., UE 200) with cell selection or reselection in an NTN.

[0137] The method 600 may begin at step 612, where the network node (e.g., network node 300) obtains information regarding a store and forward operational mode of one or more of the network node and one or more neighbor cells. For example, when the network node is a serving network node for the wireless device, the network node may obtain its own store and forward operational mode based on its own status and may obtain store and forward operational mode information regarding neighbor cells from the neighbor cells.

[0138] At step 614, the network node transmits the information regarding a store and forward operational mode of one or more of the network node and one or more neighbor cells to the wireless device. Transmitting the information regarding the store and forward operational mode of one or more of the network node and the one or more neighbor cells may comprise broadcasting system information.

[0139] At step 616, the network node may transmit an indication to the wireless device whether to perform cell selection or reselection based on the information regarding the store and forward operational mode of one or more of the network node and one or more neighbor cells. Transmitting the indication may comprise transmitting a connection release message to the wireless device.

[0140] Modifications, additions, or omissions may be made to method 600 of FIGURE 6. Additionally, one or more steps in the method of FIGURE 6 may be performed in parallel or in any suitable order.P112964WO01 PCT APPLICATION 32 of 40

[0141] The foregoing description sets forth numerous specific details. It is understood, however, that embodiments may be practiced without these specific details. In other instances, well-known circuits, structures and techniques have not been shown in detail in order not to obscure the understanding of this description. Those of ordinary skill in the art, with the included descriptions, will be able to implement appropriate functionality without undue experimentation.

[0142] References in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to implement such feature, structure, or characteristic in connection with other embodiments, whether or not explicitly described.

[0143] Although this disclosure has been described in terms of certain embodiments, alterations and permutations of the embodiments will be apparent to those skilled in the art. Accordingly, the above description of the embodiments does not constrain this disclosure. Other changes, substitutions, and alterations are possible without departing from the scope of this disclosure, as defined by the claims below.

[0144] Some example embodiments are described below.Group A Embodiments1. A method performed by a user equipment for cell selection or reselection in a non-terrestrial network (NTN), the method comprising:obtaining information regarding a store and forward operational mode of one or more of a serving cell and one or more neighbor cells; andperforming cell selection or reselection based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells.2. The method of the previous embodiment, wherein performing cell selection or reselection based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells comprises triggering cell selection or reselection based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells.P112964WO01 PCT APPLICATION 33 of 403. The method of any one of the previous embodiments, wherein performing cell selection or reselection based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells comprises prioritizing candidate cells based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells.4. The method of any one of the previous embodiments, wherein the obtained information regarding the store and forward operational mode comprises any of the factors, quantities, and properties in the embodiments and examples described herein.5. A method performed by a wireless device, the method comprising:any of the wireless device steps, features, or functions described above, either alone or in combination with other steps, features, or functions described above.6. The method of the previous embodiment, further comprising one or more additional wireless device steps, features or functions described above.Group B Embodiments7. A method performed by a network node, the method comprising:any of the steps, features, or functions described above with respect to a network node, either alone or in combination with other steps, features, or functions described above.8. The method of the previous embodiment, further comprising one or more additional network node steps, features or functions described above.Group C Embodiments9. A user equipment comprising:processing circuitry configured to perform any of the steps of any of the Group A embodiments; andpower supply circuitry configured to supply power to the processing circuitry.P112964WO01 PCT APPLICATION 34 of 4010. A network node comprising:processing circuitry configured to perform any of the steps of any of the Group B embodiments;power supply circuitry configured to supply power to the processing circuitry.11. A user equipment (UE) comprising:an antenna configured to send and receive wireless signals;radio front-end circuitry connected to the antenna and to processing circuitry, and configured to condition signals communicated between the antenna and the processing circuitry;the processing circuitry being configured to perform any of the steps of any of the Group A embodiments;an input interface connected to the processing circuitry and configured to allow input of information into the UE to be processed by the processing circuitry;an output interface connected to the processing circuitry and configured to output information from the UE that has been processed by the processing circuitry; anda battery connected to the processing circuitry and configured to supply power to the UE.

Claims

P112964WO01 PCT APPLICATION 35 of 40Claims1. A method performed by a wireless device for cell selection or reselection in a nonterrestrial network (NTN), the method comprising:obtaining (512) information regarding a store and forward operational mode of one or more of a serving cell of the wireless device and one or more neighbor cells of the wireless device; and performing (516) cell selection or reselection based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells.

2. The method of claim 1, wherein the information regarding store and forward mode of the serving cell and the one or more neighbor cells comprises one or more of:a time remaining in store and forward operation mode;a time remaining until a start of store and forward operation mode;a time remaining in non-store and forward mode; andan indication that a store and forward buffer is above a threshold value.

3. The method of any one of claims 1-2, wherein performing the cell selection or reselection based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells comprises triggering a cell selection or reselection evaluation procedure based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells.

4. The method of any one of claims 1-3, wherein performing the cell selection or reselection based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells comprises prioritizing candidate cells based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells.

5. The method of claim 4, wherein prioritizing candidate cells based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells comprises excluding candidate cells based on a store and forwardP112964WO01 PCT APPLICATION 36 of 40mode of the candidate cell.

6. The method of any one of claims 1-5, wherein performing the cell selection or reselection is further based on one or more of:an amount of data in an uplink buffer of the wireless device;a quality of service value associated with data to be transmitted or received by the wireless device; anda type of data to be transmitted or received by the wireless device.

7. The method of any one of claims 1-6, wherein obtaining information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells comprises receiving system broadcast information.

8. The method of any one of claims 1-7, further comprising receiving (514) an indication whether to perform cell selection or reselection based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells.

9. The method of claim 8, wherein receiving the indication comprises receiving a connection release message.

10. A wireless device (200) capable of performing cell selection or reselection in a nonterrestrial network (NTN), the wireless device comprising processing circuitry (202) operable to:obtain information regarding a store and forward operational mode of one or more of a serving cell of the wireless device and one or more neighbor cells of the wireless device; and perform cell selection or reselection based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells.

11. The wireless device of claim 10, wherein the information regarding store and forward mode of the serving cell and the one or more neighbor cells comprises one or more of:a time remaining in store and forward operation mode;a time remaining until a start of store and forward operation mode;a time remaining in non-store and forward mode; andP112964WO01 PCT APPLICATION 37 of 40an indication that a store and forward buffer is above a threshold value.

12. The wireless device of any one of claims 10-11, wherein the processing circuitry is operable to perform the cell selection or reselection based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells by triggering a cell selection or reselection evaluation procedure based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells.

13. The wireless device of any one of claims 10-12, wherein the processing circuitry is operable to perform the cell selection or reselection based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells by prioritizing candidate cells based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells.

14. The wireless device of claim 13, wherein prioritizing candidate cells based on the obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells comprises excluding candidate cells based on a store and forward mode of the candidate cell.

15. The wireless device of any one of claims 10-14, wherein the processing circuitry is operable to perform the cell selection or reselection further based on one or more of:an amount of data in an uplink buffer of the wireless device;a quality of service value associated with data to be transmitted or received by the wireless device; anda type of data to be transmitted or received by the wireless device.

16. The wireless device of any one of claims 10-15, wherein the processing circuitry is operable to obtain information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells by receiving system broadcast information.

17. The wireless device of any one of claims 10-16, the processing circuitry further operable to receive an indication whether to perform cell selection or reselection based on theP112964WO01 PCT APPLICATION 38 of 40obtained information regarding the store and forward operational mode of one or more of the serving cell and one or more neighbor cells.

18. The wireless device of claim 17, wherein receiving the indication comprises receiving a connection release message.

19. A method performed by a network node to assist a wireless device with cell selection or reselection in a non-terrestrial network (NTN), the method comprising:obtaining (612) information regarding a store and forward operational mode of one or more of the network node and one or more neighbor cells; andtransmitting (614) the information regarding a store and forward operational mode of one or more of the network node and one or more neighbor cells to the wireless device.

20. The method of claim 19, wherein transmitting the information regarding the store and forward operational mode of one or more of the network node and the one or more neighbor cells comprises broadcasting system information.

21. The method of any one of claims 19-20, further comprising transmitting (616) an indication to the wireless device whether to perform cell selection or reselection based on the information regarding the store and forward operational mode of one or more of the network node and one or more neighbor cells.

22. The method of claim 19, wherein transmitting the indication comprises transmitting a connection release message to the wireless device.

23. The method of any one of claims 19-22, wherein the information regarding store and forward mode of the network node and the one or more neighbor cells comprises one or more of:a time remaining in store and forward operation mode;a time remaining until a start of store and forward operation mode;a time remaining in non-store and forward mode; andan indication that a store and forward buffer is above a threshold value.P112964WO01 PCT APPLICATION 39 of 4024. A network node (300) operable to assist a wireless device (200) with cell selection or reselection in a non-terrestrial network (NTN), the network node comprising processing circuitry (302) operable to:obtain information regarding a store and forward operational mode of one or more of the network node and one or more neighbor cells; andtransmit the information regarding a store and forward operational mode of one or more of the network node and one or more neighbor cells to the wireless device.

25. The network node of claim 24, wherein the processing circuitry is operable to transmit the information regarding the store and forward operational mode of one or more of the network node and the one or more neighbor cells by broadcasting system information.

26. The network node of any one of claims 24-25, the processing circuitry further operable to transmit an indication to the wireless device whether to perform cell selection or reselection based on the information regarding the store and forward operational mode of one or more of the network node and one or more neighbor cells.

27. The network node of claim 26, wherein transmitting the indication comprises transmitting a connection release message to the wireless device.

28. The network node of any one of claims 24-27, wherein the information regarding store and forward mode of the network node and the one or more neighbor cells comprises one or more of:a time remaining in store and forward operation mode;a time remaining until a start of store and forward operation mode;a time remaining in non-store and forward mode; andan indication that a store and forward buffer is above a threshold value.

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