Systems and methods for femto cell prioritization at a user equipment in a radio resource control idle state

Abstract

A user equipment (UE) served by a femto cell of a network receives, from the femto cell, a radio resource control (RRC) connection release message comprising a macro cell reselection priority for a macro cell that is higher than a femto cell reselection priority for the femto cell, transitions to an RRC idle state in response to the RRC connection release message, determines that a femto cell camping condition is met, and de-prioritizes the macro cell for cell reselection in response to the determining that the femto cell camping condition is met such that the UE remains camped on the femto cell while in the RRC idle state notwithstanding that the macro cell reselection priority is higher than the femto cell reselection priority. Circumstances for ending such a de-prioritization of the macro cell are also discussed.

Description

SYSTEMS AND METHODS FOR FEMTO CELL PRIORITIZATION AT A USEREQUIPMENT IN A RADIO RESOURCE CONTROL IDLE STATETECHNICAL FIELD

[0001] This application relates generally to wireless communication systems, including wireless communication systems that use femto cells.BACKGROUND

[0002] Wireless mobile communication technology uses various standards and protocols to transmit data between a base station and a wireless communication device. Wireless communication system standards and protocols can include, for example, 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) (e.g., 4G), 3GPP New Radio (NR) (e.g., 5G), and Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard for Wireless Local Area Networks (WLAN) (commonly known to industry groups as Wi-Fi®).

[0003] As contemplated by the 3GPP, different wireless communication systems' standards and protocols can use various radio access networks (RANs) for communicating between a base station of the RAN (which may also sometimes be referred to generally as a RAN node, a network node, or simply a node) and a wireless communication device known as a user equipment (UE). 3GPP RANs can include, for example, Global System for Mobile communications (GSM), Enhanced Data Rates for GSM Evolution (EDGE) RAN (GERAN), Universal Terrestrial Radio Access Network (UTRAN), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and / or Next- Generation Radio Access Network (NG-RAN).

[0004] Each RAN may use one or more radio access technologies (RATs) to perform communication between the base station and the UE. For example, the GERAN implements GSM and / or EDGE RAT, the UTRAN implements Universal Mobile Telecommunication System (UMTS) RAT or other 3GPP RAT, the E-UTRAN implements LTE RAT (sometimes simply referred to as LTE), and NG-RAN implements NR RAT (sometimes referred to herein as 5G RAT, 5GNR RAT, or simply NR). In certain deployments, the E-UTRAN may also implement NR RAT. In certain deployments, NG-RAN may also implement LTE RAT.

[0005] A base station used by a RAN may correspond to that RAN. One example of an E-UTRAN base station is an Evolved Universal Terrestrial Radio Access Network (E- UTRAN) Node B (also commonly denoted as evolved Node B, enhanced Node B, eNodeB, or eNB). One example of an NG-RAN base station is a next generation Node B (also sometimes referred to as a g Node B or gNB).

[0006] A RAN provides its communication services with external entities through its connection to a core network (CN). For example, E-UTRAN may utilize an Evolved Packet Core (EPC) while NG-RAN may utilize a 5G Core Network (5GC).

[0007] Frequency bands for 5G NR may be separated into two or more different frequency ranges. For example, Frequency Range 1 (FR1) may include frequency bands operating in sub-6 gigahertz (GHz) frequencies, some of which are bands that may be used by previous standards, and may potentially be extended to cover new spectrum offerings from 410 megahertz (MHz) to 7125 MHz. Frequency Range 2 (FR2) may include frequency bands from 24.25 GHz to 52.6 GHz. Note that in some systems, FR2 may also include frequency bands from 52.6 GHz to 71 GHz (or beyond). Bands in the millimeter wave (mmWave) range of FR2 may have smaller coverage but potentially higher available bandwidth than bands in FR1. Skilled persons will recognize these frequency ranges, which are provided by way of example, may change from time to time or from region to region.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0008] To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.

[0009] FIG. 1 illustrates a flow diagram for operations of a UE corresponding to camping (remaining camped) on a femto cell after transitioning to an RRC idle state, according to embodiments discussed herein.

[0010] FIG. 2 illustrates a femto cell configured according to a femto cell configuration and a macro cell that is configured according to a macro cell configuration, according to embodiments discussed herein.

[0011] FIG. 3 illustrates a method of a UE served by a femto cell of a network, according to embodiments discussed herein.

[0012] FIG. 4 illustrates a method of a UE that is camped on a femto cell of a network and that has implemented a de-prioritization of a macro cell for cell reselection, according to embodiments discussed herein.

[0013] FIG. 5 illustrates an example architecture of a wireless communication system, according to embodiments disclosed herein.

[0014] FIG. 6 illustrates a system for performing signaling between a wireless device and a network device, according to embodiments disclosed herein.DETAILED DESCRIPTION

[0015] Various embodiments are described with regard to a UE. However, reference to a UE is merely provided for illustrative purposes. The example embodiments may be utilized with any electronic component that may establish a connection to a network and is configured with the hardware, software, and / or firmware to exchange information and data with the network. Therefore, the UE as described herein is used to represent any appropriate electronic component.

[0016] A femto cell of a network is a cell that is deployed over a smaller area than that covered by a macro cell of the network (e.g., to enhance cellular coverage for users in the wireless communication system). Further, as compared to a macro cell of the network, a femto cell may be designed to (have the capacity to) provide service to a relatively smaller number of provisioned users.

[0017] Femto cells (e.g., 5G femto cells) are increasingly used by wireless carriers / service providers to provide extended coverage in various applications (e.g., residential and enterprise applications). Femto cells may be introduced in these various contexts in order to, for example, offload network congestion from the macro cell, extend coverage of the network, and / or increase data capacity for users of the network. One example of a useful femto cell case is that of indoor users for whom coverage as provided by an outdoor macro cell may be somewhat limited due to various fading conditions. By offloading traffic from the macro cell, femto cells both reduce network congestion with respect to the outdoor macro cell and improve network performance for the indoor users. This can lead to a better user experience (for example, in areas with high network traffic and lower radio frequency (RF) coverage).

[0018] Further, it is possible to configure a femto cell as a private femto cell (private networks), thereby providing improved security and privacy as compared to the case ofaccess over a public macro cell. Femto cells may also be designed to be more energyefficient than macro cells.

[0019] Femto cell solutions may be leveraged by wireless carriers / service providers for business and / or customer retention reasons. For example, the deployment of a femto cell for the customer may provide an additional sales avenue while simultaneously ensuring good indoor coverage for the customer (take, for example, the case of medium-sized offices).

[0020] Femto cell use reduces the overall energy consumption attributable to the network, leading to cost savings and a reduced carbon footprint (particularly when the femto cell works “smarter” with mobile devices / UEs).

[0021] In some contexts, it may be desirable to cause the UE that is in / has entered a radio resource control (RRC) idle state to perform cell reselection on and / or to femto cell(s) rather than macro cell(s) when femto cells are available, in order to achieve one or more of the benefits described above. However, the UE may not be properly configured to reselect to an available femto cell instead of to an available macro cell in some circumstance.

[0022] Consider, for example, a 5G non-standalone context where a UE uses an NR femto cell as its current serving cell. An eNB of the network may set a reselection priority of neighbor macro cells higher than the priority of the NR femto cell. Due to higher priority of the macro cells (which may, e.g., not always be 5G capable), the UE will perform cell reselection to one of the macro cells (rather than to the femto cell / rather than remaining on the femto cell) once it goes into an RRC idle state. In such contexts, the only way to re-attach to femto cell is to toggle airplane mode (APM) or to reboot the UE. However, it may be that as soon as the UE again goes into the RRC idle state, it again reverts to cell reselection as among neighboring macro cells (again, due to the higher priority of the macro cells).

[0023] Corresponding to such cases, there may be an extraneous load on the network, higher battery consumption due to signaling in the RRC idle state for reselection procedures, and / or a relatively poorer user experience for users that could otherwise be benefitted by using the femto cell (e.g., voice quality and / or data throughputs for such users may be relatively worse, particularly in cases where the macro cell is congested).

[0024] It may be that wireless carriers / service providers find it untenable to modify a reselection priority scheme from the perspective of the macro cells. This is because anymodification of a macro cell priority may go against prior / active production network planning assumptions, with the result that the network is unfavorably changed at the macro level. For example, any change of a reselection priority value assigned to / for a single macro cell can impact the effective coverage of both that macro cell and / or the effective coverage of other nearby cells of the production network.

[0025] Accordingly, device-side solutions for causing a UE to prioritize reselection to available femto cells over macro cells are useful.

[0026] Systems and methods disclosed herein relate to UEs that are configured to, when in an RRC idle state, camp on a femto cell instead of a macro cell (even when the macro cell has a higher configured reselection priority than that of the femto cell) when applicable criteria are met. Examples of such criteria that may be so used now follow.

[0027] In some embodiments, a UE may be configured to camp on a femto cell instead of a macro cell when a measured signal strength (e.g., a reference signal strength indicator (RSSI) and / or a reference signal received power (RSRP)) is stronger for the femto cell than for the macro cell. This conclusion may be based on measured signal strength values in measurement reports generated at the UE using UE measurements of each of the femto cell and the macro cell.

[0028] In some such cases, the UE may conclude that the measured signal strength is stronger for the femto cell than for the macro cell after seeing this borne out across various measurement reports over time. In some such cases, the UE may be configured to make the conclusion that the measured signal strength is stronger for the femto cell than for the macro cell when the UE understands its mobility condition to be stationary.

[0029] In some embodiments, a UE may be configured to camp on a femto cell instead of a macro cell when a non-standalone (NSA) mode (e.g., an NSA 5G mode) is made available at the UE through a use of the femto cell (e.g., and where the NSA mode would not otherwise be available corresponding to the case of camping on the macro cell).

[0030] In some embodiments, a UE may be configured to camp on a femto cell instead of a macro cell when a percentage of resource allocations available on / for a secondary cell group (SCG) of the femto cell is higher than a percentage of resource allocations that is available on an SCG of the macro cell (this indicates that relatively better performance for the UE is possible generally when camped on femto cell). In other words, a UE may be configured to camp on a femto cell instead of a macro cell when theSCG for the femto cell is better (from a performance perspective) than the SCG for the macro cell.

[0031] In some embodiments, a UE may be configured to camp on a femto cell instead of a macro cell when a level of congestion is detected on the macro cell. The level of congestion may be based on an analysis of or a current metric for a link performance with the macro cell (e.g., a channel quality indicator (CQI), an achieved / achievable modulation and coding scheme (MCS) on the macro cell, etc.).

[0032] In some embodiments, a UE may be configured to camp on a femto cell instead of a macro cell when a different values for a theoretical throughput metric for the femto cell versus the macro cell indicate that camping on the femto cell would result in a better value for the theoretical throughput metric. Examples of such theoretical throughput metrics include bandwidth, carrier aggregation (CA) support, buffer status reports (BSRs), etc.

[0033] In some embodiments, a UE may be configured to camp on a femto cell instead of a macro cell when voice key performance indicators (KPIs) (voice-data-related KPIs) for the femto cell are better than those for the macro cell. Examples of such KPIs may include, for example, whether the femto cell has a lower block error rate (BLER) than the macro cell, whether the femto cell has a better RSRP than the macro cell (e.g., with the threshold being configurable) in order to determine femto is better RF wise, whether the femto cell or the macro cell has the higher internet protocol (IP) multimedia subsystem (IMS) registration rate, which of the femto cell and the macro cell has experienced fewer random access channel (RACH) failures, whether the femto cell has experienced fewer call drops on voice over LTE (VoLTE) and / or circuit switched (CS) on the femto cell as compared to the macro cell, etc.

[0034] In some embodiments, a UE may be configured to camp on a femto cell instead of a macro cell when it is within a geofence corresponding to the femto cell. In some cases, the geofencing corresponding to the femto cell is built at the UE (e.g., corresponding to the UE's measurements on the femto cell over time).

[0035] Based on one or more of the above criteria, the UE may determine to deprioritize the macro cell from the UE perspective, with the result that the UE camps (stays camped) to the femto cell. Such a detection pattern allows the UE to stay on the femto cell if / when an overall better user experience is expected based on these one or more criteria.

[0036] Based on the above measurement / criteria (e.g., including an applicable geofencing definition), the UE may determine to camp (remain camped) on a femto cell instead of reselecting to a macro cell (even in the case where the macro cell has a higher configured reselection priority).

[0037] Note that in cases where a UE uses multiple ones of the criteria discussed above, for determining whether to camp (remain camped) on the femto cell, the UE may set its own ranking criteria for evaluating the relative importance between the various used criteria.

[0038] FIG. 1 illustrates a flow diagram 100 for operations of a UE 102 corresponding to camping (remaining camped) on a femto cell 104 after transitioning to an RRC idle state, according to embodiments discussed herein. The flow diagram 100 illustrates communications between the UE 102, the femto cell 104, and a macro cell 106.

[0039] As illustrated, the UE 102 begins in an RRC connected state 108 with the femto cell 104. Then, the femto cell 104 sends 110 the UE 102 an RRC connection release message. This RRC connection release message contains a cell reselection priority for the macro cell 106 that is higher than a cell reselection priority applicable to the femto cell 104. Accordingly, from the perspective of the UE 102, the macro cell 106 is formally configured with a higher reselection priority than that used by the femto cell 104.

[0040] In response to the RRC connection release message, the UE 102 leaves the RRC connected state 108 and enters 112 an RRC idle state. Note that the UE may be configured, as a general matter, to actively attempt to camp on a cell of the network (e.g., one of the femto cell 104 and the macro cell 106) while in this RRC idle state.

[0041] At this juncture, the UE receives 114 (e.g., via broadcast signaling from the macro cell 106) an intra-frequency cell reselection subscription ID message. This message may contain frequency(s), physical cell identity(s) (PCI(s)), and / or public land mobile network(s) (PLMN(s)) for cells corresponding to the assumed area of the broadcast (e.g., for the macro cell 106 and potentially neighbor cells of the macro cell 106). By this signaling, the UE 102 is informed that the macro cell 106 is available for camping at the present location of the UE 102. Note that due to the fact that the UE was just in an RRC connected state 108 with the femto cell 104, the UE is also aware that the femto cell 104 is available for camping at the present location of the UE 102.

[0042] The UE 102 then proceeds to perform macro cell idle state measurements 116 of the macro cell 106. Based on the results of these measurements, the UE 102 determines that the macro cell idle state measurements 116 meet applicable requirements (e.g., frequency requirements, RSRP requirements, and / or reference signal received quality (RSRQ) requirements) for cell reselection / camping on the macro cell 106.

[0043] The UE 102 also proceeds to perform femto cell idle state measurements 118 of the femto cell 104. Based on the results of these measurements, the UE 102 determines that the femto cell idle state measurements 118 meet conditions for camping on the femto cell 104. These conditions may be, for example, one or more of the criteria for the use of femto cell reselection / camping as discussed herein. Note that for criteria where comparison of aspects of the femto cell 104 to aspects of the macro cell 106 as described herein, the macro cell idle state measurements 116 and the femto cell idle state measurements 118 may be compared.

[0044] In the event that the UE 102 determines (e.g., based on one or more of the criteria discussed herein) that it should camp of the femto cell 104 rather than the macro cell 106 (notwithstanding the higher priority of the macro cell 106), then the UE 102 performs a deemed expiration 120 of a timer 122 for the validity of the reselection priority of the macro cell 106 that was provided in the RRC connection release message. In other words, the UE 102 considers the timer 122 for the validity of the reselection priority of the macro cell 106 as expired even though the timer 122 has not necessarily finished its run. As illustrated, in some cases, the timer 122 may be a T320 timer.

[0045] Because of the deemed expiration 120 of the reselection priority of the macro cell 106, the macro cell 106 is altogether removed from consideration by the UE 102 when the UE 102 is looking for a cell on which to camp. Accordingly, this deemed expiration 120 of the timer 122 is an example of a mechanism for de-prioritizing the macro cell 106, as indicated in FIG. 1.

[0046] As a result of de-prioritization, the UE 102 will not perform cell reselection to / will not camp on the macro cell 106. Instead, as illustrated, the UE 102 ultimately camps 124 on the femto cell 104. Note that this occurs notwithstanding that the original RRC connection release message from the femto cell 104 indicated a relatively higher reselection priority for the macro cell 106 as compared to a priority for the femto cell 104.

[0047] The de-prioritization of a macro cell at a UE may remain in place until a macro cell de-prioritization termination condition is met. In other words, if a macro cell deprioritization termination condition is met, the de-prioritization of the macro cell at the UE (e.g., immediately) ends. Examples of macro cell de-prioritization termination conditions now follow.[004S] As illustrated in FIG. 1, in some embodiments, an applicable macro cell de- prioritization termination condition is the expiration of a macro cell de-prioritization timer. The macro cell de-prioritization timer may be set at the UE 102 at the time that the macro cell 106 is de-prioritized at the UE 102 (e.g., at the time of the deemed expiration 120 of the timer 122). Once the macro cell de-prioritization time expires, the de- prioritization of the macro cell 106 at the UE 102 is removed (and the UE 102 is thus free to reselect to / camp on the macro cell 106 according to its relatively higher priority going forward).

[0049] In some embodiments, an applicable macro cell de-prioritization termination condition is that a UE moves out of the coverage of the femto cell (e.g., leaves a geofence corresponding to the femto cell).

[0050] In some embodiments, an applicable macro cell de-prioritization termination condition is that a measured signal strength of the macro cell is greater than a measured signal strength of the femto cell.

[0051] In some embodiments, an applicable macro cell de-prioritization termination condition is that a threshold number of RACH failures has occurred on / with the femto cell.

[0052] Various benefits are realized through the use of femto cell camping prioritization embodiments disclosed herein. First example benefits include the minimization of signaling due to cell reselection in an RRC idle state.

[0053] Additional example benefits include battery saving benefits. For example, in the case of a same carrier frequency and / or an infra-frequency case as between a femto cell and a macro cell, the femto cell may be overall more energy efficient than an LTE / NR macro cell from the network perspective. Further, on the UE side, battery consumption is relatively lower in the case that the UE camps (remains camped) on the femto cell (corresponding to the relatively better radio conditions on / relatively shorter communication range with the femto cell).

[0054] Additional example benefits include improved indoor user experience levels through the femto cell as compared to through the macro cell (e.g., for either and / or both of voice and / or data).

[0055] Additional example benefits include the increased relative use of public femto cells, which have relatively more flexibility with respect to upgrading as compared to macro cells and thus offer a more straightforward way to adopt beneficial evolutions within the wireless communication system (at least at the femto cell level).

[0056] FIG. 2 illustrates a femto cell 202 configured according to a femto cell configuration 204 and a macro cell 206 that is configured according to a macro cell configuration 208, according to embodiments discussed herein. The femto cell configuration 204 and the macro cell configuration 208 may be known to a UE based on this information being broadcast in a system information block (SIB) (e.g., a SIB3 210 in the case of the femto cell configuration 204 and a SIB5 212 in the case of the macro cell configuration 208, as illustrated).

[0057] As also shown in FIG. 2, the femto cell 202 has a femto cell reselection priority 214 of value 5, while the macro cell reselection priority 216 has a macro cell reselection priority 216 of value 7. Accordingly, the UE will understand that as a formal matter that the macro cell reselection priority 216 for the macro cell 206 is higher than the femto cell reselection priority 214 for the femto cell 202. However, using embodiments discussed herein, the UE may nevertheless prioritize cell reselection to / camping on the femto cell 202 over the macro cell 206, notwithstanding that the macro cell reselection priority 216 is higher than the femto cell reselection priority 214.

[0058] Per carrier configuration and network planning, it may be that macro cells are, as a general matter, formally prioritized (e.g., have a higher assigned cell reselection priority value) over femto cells, in order to provide wider planned coverage for an area based on its general configuration (dense, urban, rural, landforms). Wireless carners / service providers may be unwilling to change this overall coverage plan to account for small indoor areas.

[0059] Use of the embodiments for prioritizing femto cells for camping / cell reselection as discussed herein can be checked-for at a UE upon review of relevant SIBs used by the base station and / or received at device baseband. Once this procedure confirms that the macro cell is configured with a relatively higher cell reselection priority than the femto cell, if the UE ignores this configured cell reselection priority7order as defined by thenetwork and instead remains camped on the femto cell after transitioning to the RRC idle state, various additional checks may be performed. For example, a measurement report from the femto cell may be evaluated to see if it corresponds to the potential use of related femto cell prioritization criteria as described herein. Further, a geofencing definition for the femtocell at the UE may be evaluated to determine whether it corresponds to the potential use of related femto cell prioritization criteria as described herein. Other aspects of the UE related to other femto cell prioritization criteria discussed herein may also be checked.

[0060] FIG. 3 illustrates a method 300 of a UE served by a femto cell of a network, according to embodiments discussed herein. The method 300 includes receiving 302, from the femto cell, an RRC connection release message comprising a macro cell reselection priority for a macro cell that is higher than a femto cell reselection priority for the femto cell. The method 300 further includes transitioning 304 to an RRC idle state in response to the RRC connection release message. The method 300 further includes determining 306 that a femto cell camping condition is met. The method 300 further includes de-prioritizing 308 the macro cell for cell reselection in response to the determining that the femto cell camping condition is met such that the UE remains camped on the femto cell while in the RRC idle state notwithstanding that the macro cell reselection priority is higher than the femto cell reselection priority.

[0061] In some embodiments of the method 300, the de-prioritizing the macro cell comprises deeming a validity timer for the macro cell reselection priority to be expired.

[0062] In some embodiments, the method 300 further includes measuring a first measured signal strength of the femto cell and a second measured signal strength of the macro cell, and the femto cell camping condition comprises that the first measured signal strength of the femto cell is stronger than the second measured signal strength of the macro cell.

[0063] In some embodiments of the method 300, the femto cell camping condition comprises that a use of the femto cell enables a use of an NSA 5G mode at the UE.

[0064] In some embodiments of the method 300, the femto cell camping condition comprises that a first SCG for the femto cell is better than a second SCG for the macro cell.

[0065] In some embodiments of the method 300, the femto cell camping condition comprises that a level of congestion detected on the macro cell meets a threshold.

[0066] In some embodiments of the method 300, the femto cell camping condition comprises that a first value for a theoretical throughput metric at the femto cell is better than a second value for the theoretical throughput metric at the macro cell.

[0067] In some embodiments of the method 300, the femto cell camping condition comprises first voice KPIs for the femto cell are better than second voice KPIs for the macro cell.

[0068] In some embodiments of the method 300, the femto cell camping condition comprises that the UE is within a geofence corresponding to the femto cell.

[0069] In some embodiments, the method 300 further includes determining that a macro cell de-prioritization termination condition is met; and ending the de-prioritization of the macro cell in response to determining that the macro cell de-prioritization termination condition is met. In some such embodiments, the macro cell de-prioritization termination condition comprises that the UE has moved out of coverage of the femto cell. In some such embodiments, the macro cell de-prioritization termination condition comprises that a first measured signal strength of the macro cell is greater than a second measured signal strength of the femto cell. In some such embodiments, the macro cell de- prioritization termination condition comprises that a threshold number of RACH failures has occurred on the femto cell. In some such embodiments, the macro cell de- prioritization termination condition comprises that a timer associated with the de- prioritization of the macro cell has expired.

[0070] In some embodiments of the method 300, the femto cell comprises a public femto cell.

[0071] In some embodiments of the method 300, the femto cell comprises a private femto cell.

[0072] FIG. 4 illustrates a method 400 of a UE that is camped on a femto cell of a network and that has implemented a de-prioritization of a macro cell for cell reselection, according to embodiments discussed herein. The method 400 includes determining 402 that a macro cell de-prioritization termination condition is met. The method 400 further includes ending 404 the de-prioritization of the macro cell in response to determining that the macro cell de-prioritization termination condition is met. The method 400 further includes performing 406 cell reselection from the femto cell to the macro cell after ending the de-prioritization of the macro cell.

[0073] In some embodiments of the method 400, the macro cell de-prioritization termination condition comprises that the UE has moved out of coverage of the femto cell.

[0074] In some embodiments of the method 400, the macro cell de-prioritization termination condition comprises that a first measured signal strength of the macro cell is greater than a second measured signal strength of the femto cell.

[0075] In some embodiments of the method 400, the macro cell de-prioritization termination condition comprises that a threshold number of RACH failures has occurred on the femto cell.

[0076] In some embodiments of the method 400, the macro cell de-prioritization termination condition comprises that a timer associated with the de-prioritization of the macro cell has expired.

[0077] In some embodiments of the method 400, the femto cell comprises a public femto cell.

[0078] In some embodiments of the method 400, the femto cell comprises a private femto cell.

[0079] FIG. 5 illustrates an example architecture of a wireless communication system 500, according to embodiments disclosed herein. The following description is provided for an example wireless communication system 500 that operates in conjunction with the LTE system standards and / or 5G or NR system standards as provided by 3GPP technical specifications.

[0080] As shown by FIG. 5, the wireless communication system 500 includes UE 502 and UE 504 (although any number of UEs may be used). In this example, the UE 502 and the UE 504 are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices connectable to one or more cellular networks), but may also comprise any mobile or non-mobile computing device configured for wireless communication.

[0081] The UE 502 and UE 504 may be configured to communicatively couple with a RAN 506. In embodiments, the RAN 506 may be NG-RAN, E-UTRAN, etc. The UE 502 and UE 504 utilize connections (or channels) (shown as connection 508 and connection 510, respectively) with the RAN 506, each of which comprises a physical communications interface. The RAN 506 can include one or more base stations (such asbase station 512 and base station 514) that enable the connection 508 and connection 510.

[0082] In this example, the connection 508 and connection 510 are air interfaces to enable such communicative coupling, and may be consistent with RAT(s) used by the RAN 506, such as, for example, an LTE and / or NR.

[0083] In some embodiments, the UE 502 and UE 504 may also directly exchange communication data via a sidelink interface 516. The UE 504 is shown to be configured to access an access point (shown as AP 518) via connection 520. By way of example, the connection 520 can comprise a local wireless connection, such as a connection consistent with any IEEE 802.11 protocol, wherein the AP 518 may comprise a Wi-Fi® router. In this example, the AP 518 may be connected to another network (for example, the Internet) without going through a CN 524.

[0084] In embodiments, the UE 502 and UE 504 can be configured to communicate using orthogonal frequency division multiplexing (OFDM) communication signals with each other or with the base station 512 and / or the base station 514 over a multicarrier communication channel in accordance with various communication techniques, such as, but not limited to, an orthogonal frequency division multiple access (OFDMA) communication technique (e.g., for downlink communications) or a single carrier frequency division multiple access (SC-FDMA) communication technique (e.g., for uplink and ProSe or sidelink communications), although the scope of the embodiments is not limited in this respect. The OFDM signals can comprise a plurality of orthogonal subcarriers.

[0085] In some embodiments, all or parts of the base station 512 or base station 514 may be implemented as one or more software entities running on server computers as part of a virtual network. In addition, or in other embodiments, the base station 512 or base station 514 may be configured to communicate with one another via interface 522. In embodiments where the wireless communication sy stem 500 is an LTE system (e.g., when the CN 524 is an EPC), the interface 522 may be an X2 interface. The X2 interface may be defined between two or more base stations (e.g., two or more eNBs and the like) that connect to an EPC, and / or between two eNBs connecting to the EPC. In embodiments where the wireless communication system 500 is an NR system (e.g., when CN 524 is a 5GC), the interface 522 may be an Xn interface. The Xn interface is defined between two or more base stations (e.g., two or more gNBs and the like) that connect to5GC, between a base station 12 (e.g., a gNB) connecting to 5GC and an eNB, and / or between two eNBs connecting to 5GC (e.g., CN 524).

[0086] The RAN 506 is shown to be communicatively coupled to the CN 524. The CN 524 may comprise one or more network elements 526, which are configured to offer various data and telecommunications services to customers / subscribers (e.g., users of UE 502 and UE 504) who are connected to the CN 524 via the RAN 506. The components of the CN 524 may be implemented in one physical device or separate physical devices including components to read and execute instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium).

[0087] In embodiments, the CN 524 may be an EPC, and the RAN 506 may be connected with the CN 524 via an SI interface 528. In embodiments, the SI interface 528 may be split into two parts, an SI user plane (Sl-U) interface, which carries traffic data between the base station 512 or base station 514 and a serving gateway (S-GW), and the Sl-MME interface, which is a signaling interface between the base station 512 or base station 514 and mobility management entities (MMEs).

[0088] In embodiments, the CN 524 may be a 5GC, and the RAN 506 may be connected with the CN 524 via an NG interface 528. In embodiments, the NG interface 528 may be split into two parts, an NG user plane (NG-U) interface, which carries traffic data between the base station 512 or base station 514 and a user plane function (UPF), and the SI control plane (NG-C) interface, which is a signaling interface between the base station 512 or base station 514 and access and mobility management functions (AMFs).

[0089] Generally, an application server 530 may be an element offering applications that use IP bearer resources with the CN 524 (e.g., packet switched data services). The application server 530 can also be configured to support one or more communication services (e.g., VoIP sessions, group communication sessions, etc.) for the UE 502 and UE 504 via the CN 524. The application server 530 may communicate with the CN 524 through an IP communications interface 532.

[0090] FIG. 6 illustrates a system 600 for performing signaling 632 between a wireless device 602 and a network device 618, according to embodiments disclosed herein. The system 600 may be a portion of a wireless communications system as herein described. The wireless device 602 may be, for example, a UE of a wireless communication system.The network device 618 may be, for example, a base station (e.g., an eNB or a gNB) of a wireless communication system.

[0091] The wireless device 602 may include one or more processor(s) 604. The processor(s) 604 may execute instructions such that various operations of the wireless device 602 are performed, as described herein. The processor(s) 604 may include one or more baseband processors implemented using, for example, a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0092] The wireless device 602 may include a memory 606. The memory 606 may be a non-transitory computer-readable storage medium that stores instructions 608 (which may include, for example, the instructions being executed by the processor(s) 604). The instructions 608 may also be referred to as program code or a computer program. The memory 606 may also store data used by, and results computed by, the processor(s) 604.

[0093] The wireless device 602 may include one or more transceiver(s) 610 that may include RF transmitter circuitry and / or receiver circuitry that use the antenna(s) 612 of the wireless device 602 to facilitate signaling (e.g., the signaling 632) to and / or from the wireless device 602 with other devices (e.g., the network device 618) according to corresponding RATs.

[0094] The wireless device 602 may include one or more antenna(s) 612 (e.g., one, two, four, or more). For embodiments with multiple antenna(s) 612, the wireless device 602 may leverage the spatial diversity of such multiple antenna(s) 612 to send and / or receive multiple different data streams on the same time and frequency resources. This behavior may be referred to as, for example, multiple input multiple output (MIMO) behavior (referring to the multiple antennas used at each of a transmitting device and a receiving device that enable this aspect). MIMO transmissions by the wireless device 602 may be accomplished according to precoding (or digital beamforming) that is applied at the wireless device 602 that multiplexes the data streams across the antenna(s) 612 according to known or assumed channel characteristics such that each data stream is received with an appropriate signal strength relative to other streams and at a desired location in the spatial domain (e.g., the location of a receiver associated with that data stream). Certain embodiments may use single user MIMO (SU-MIMO) methods (wherethe data streams are all directed to a single receiver) and / or multi user MIMO (MU- MIMO) methods (where individual data streams may be directed to individual (different) receivers in different locations in the spatial domain).

[0095] In certain embodiments having multiple antennas, the wireless device 602 may implement analog beamforming techniques, whereby phases of the signals sent by the antenna(s) 612 are relatively adjusted such that the (joint) transmission of the antenna(s) 612 can be directed (this is sometimes referred to as beam steering).

[0096] The wireless device 602 may include one or more interface(s) 614. The interface(s) 614 may be used to provide input to or output from the wireless device 602. For example, a wireless device 602 that is a UE may include interface(s) 614 such as microphones, speakers, a touchscreen, buttons, and the like in order to allow for input and / or output to the UE by a user of the UE. Other interfaces of such a UE may be made up of transmitters, receivers, and other circuitry (e.g., other than the transceiver(s) 610 / antenna(s) 612 already described) that allow for communication between the UE and other devices and may operate according to known protocols (e.g., Wi-Fi®, Bluetooth®, and the like).

[0097] The wireless device 602 may include a femto cell reselection prioritization module 616. The femto cell reselection prioritization module 616 may be implemented via hardware, software, or combinations thereof. For example, the femto cell reselection prioritization module 616 may be implemented as a processor, circuit, and / or instructions 608 stored in the memory 606 and executed by the processor(s) 604. In some examples, the femto cell reselection prioritization module 616 may be integrated within the processor(s) 604 and / or the transceiver(s) 610. For example, the femto cell reselection prioritization module 616 may be implemented by a combination of software components (e.g., executed by a DSP or a general processor) and hardware components (e.g., logic gates and circuitry) within the processor(s) 604 or the transceiver(s) 610.

[0098] The femto cell reselection prioritization module 616 may be used for various aspects of the present disclosure, for example, aspects of FIG. 3 and / or FIG. 4. In some embodiments, the femto cell reselection prioritization module 616 may configure the wireless device 602 to, for example, receive, from a femto cell, an RRC connection release message comprising a macro cell reselection priority for a macro cell that is higher than a femto cell reselection priority for the femto cell, transition to an RRC idle state in response to the RRC connection release message, determine that a femto cellcamping condition is met, and de-priontize the macro cell for cell reselection in response to the determining that the femto cell camping condition is met such that the UE remains camped on the femto cell while in the RRC idle state notwithstanding that the macro cell reselection priority is higher than the femto cell reselection priority. In some embodiments, the femto cell reselection prioritization module 616 may configure the wireless device 602 to, for example, determine that a macro cell de-prioritization termination condition is met, end a de-prioritization of a macro cell in response to determining that the macro cell de-prioritization termination condition is met, and perform cell reselection from the femto cell to the macro cell after ending the de- prioritization of the macro cell.

[0099] The network device 618 may include one or more processor(s) 620. The processor(s) 620 may execute instructions such that various operations of the network device 618 are performed, as described herein. The processor(s) 620 may include one or more baseband processors implemented using, for example, a CPU, a DSP, an ASIC, a controller, an FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0100] The network device 618 may include a memory 622. The memory' 622 may be a non-transitory computer-readable storage medium that stores instructions 624 (which may include, for example, the instructions being executed by the processor(s) 620). The instructions 624 may also be referred to as program code or a computer program. The memory 622 may also store data used by, and results computed by, the processor(s) 620.

[0101] The network device 618 may include one or more transceiver(s) 626 that may include RF transmitter circuitry and / or receiver circuitry that use the antenna(s) 628 of the network device 618 to facilitate signaling (e.g., the signaling 632) to and / or from the network device 618 with other devices (e.g., the wireless device 602) according to corresponding RATs.

[0102] The network device 618 may include one or more antenna(s) 628 (e.g., one, two, four, or more). In embodiments having multiple antenna(s) 628, the network device 618 may perform MIMO, digital beamforming, analog beamforming, beam steering, etc., as has been described.

[0103] The network device 618 may include one or more interface(s) 630. The interface(s) 630 may be used to provide input to or output from the network device 618. For example, a network device 618 that is a base station may include interface(s) 630made up of transmitters, receivers, and other circuitry (e.g., other than the transceiver(s) 626 / antenna(s) 628 already described) that enables the base station to communicate with other equipment in a core network, and / or that enables the base station to communicate with external networks, computers, databases, and the like for purposes of operations, administration, and maintenance of the base station or other equipment operably connected thereto.

[0104] Embodiments contemplated herein include an apparatus comprising means to perform one or more elements of any of the method 300 and / or the method 400. This apparatus may be, for example, an apparatus of a UE (such as a wireless device 602 that is a UE, as described herein).

[0105] Embodiments contemplated herein include one or more non-transitory computer-readable media comprising instructions to cause an electronic device, upon execution of the instructions by one or more processors of the electronic device, to perform one or more elements of any of the method 300 and / or the method 400. This non-transitory computer-readable media may be, for example, a memory of a UE (such as a memory 606 of a wireless device 602 that is a UE, as described herein).

[0106] Embodiments contemplated herein include an apparatus comprising logic, modules, or circuitry to perform one or more elements of any of the method 300 and / or the method 400. This apparatus may be, for example, an apparatus of a UE (such as a wireless device 602 that is a UE, as described herein).

[0107] Embodiments contemplated herein include an apparatus comprising: one or more processors and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of any of the method 300 and / or the method 400. This apparatus may be, for example, an apparatus of a UE (such as a wireless device 602 that is a UE, as described herein).

[0108] Embodiments contemplated herein include a signal as described in or related to one or more elements of any of the method 300 and / or the method 400.

[0109] Embodiments contemplated herein include a computer program or computer program product comprising instructions, wherein execution of the program by a processor is to cause the processor to carry out one or more elements of any of the method 300 and / or the method 400. The processor may be a processor of a UE (such as a processor(s) 604 of a wireless device 602 that is a UE, as described herein). Theseinstructions may be, for example, located in the processor and / or on a memory of the UE (such as a memory 606 of a wireless device 602 that is a UE, as described herein).

[0110] For one or more embodiments, at least one of the components set forth in one or more of the preceding figures may be configured to perform one or more operations, techniques, processes, and / or methods as set forth herein. For example, a baseband processor as described herein in connection with one or more of the preceding figures may be configured to operate in accordance with one or more of the examples set forth herein. For another example, circuitry associated with a UE, base station, network element, etc. as described above in connection with one or more of the preceding figures may be configured to operate in accordance with one or more of the examples set forth herein.

[0111] Any of the above described embodiments may be combined with any other embodiment (or combination of embodiments), unless explicitly stated otherwise. The foregoing description of one or more implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of embodiments to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments.

[0112] Embodiments and implementations of the systems and methods described herein may include various operations, which may be embodied in machine-executable instructions to be executed by a computer system. A computer system may include one or more general-purpose or special-purpose computers (or other electronic devices). The computer system may include hardware components that include specific logic for performing the operations or may include a combination of hardware, software, and / or firmware.

[0113] It should be recognized that the systems described herein include descriptions of specific embodiments. These embodiments can be combined into single systems, partially combined into other systems, split into multiple systems or divided or combined in other ways. In addition, it is contemplated that parameters, attributes, aspects, etc. of one embodiment can be used in another embodiment. The parameters, attributes, aspects, etc. are merely described in one or more embodiments for clarity, and it is recognized that the parameters, attributes, aspects, etc. can be combined with or substituted for parameters, attributes, aspects, etc. of another embodiment unless specifically disclaimed herein.

[0114] It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users.

[0115] Although the foregoing has been described in some detail for purposes of clarity, it will be apparent that certain changes and modifications may be made without departing from the principles thereof. It should be noted that there are many alternative ways of implementing both the processes and apparatuses described herein. Accordingly, the present embodiments are to be considered illustrative and not restrictive, and the description is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.

Claims

CLAIMS1. A method of a user equipment (UE) served by a femto cell of a network, comprising: receiving, from the femto cell, a radio resource control (RRC) connection release message comprising a macro cell reselection priority for a macro cell that is higher than a femto cell reselection priority for the femto cell; transitioning to an RRC idle state in response to the RRC connection release message; determining that a femto cell camping condition is met; and de-prioritizing the macro cell for cell reselection in response to the determining that the femto cell camping condition is met such that the UE remains camped on the femto cell while in the RRC idle state notwithstanding that the macro cell reselection priority is higher than the femto cell reselection priority.

2. The method of claim 1, wherein the de-prioritizing the macro cell comprises deeming a validity timer for the macro cell reselection priority to be expired.

3. The method of claim 1, further comprising measuring a first measured signal strength of the femto cell and a second measured signal strength of the macro cell, wherein the femto cell camping condition comprises that the first measured signal strength of the femto cell is stronger than the second measured signal strength of the macro cell.

4. The method of claim 1, wherein the femto cell camping condition comprises that a use of the femto cell enables a use of a non-standalone (NSA) 5G mode at the UE.

5. The method of claim 1, wherein the femto cell camping condition comprises that a first secondary cell group (SCG) for the femto cell is better than a second SCG for the macro cell.

6. The method of claim 1, wherein the femto cell camping condition comprises that a level of congestion detected on the macro cell meets a threshold.

7. The method of claim 1, wherein the femto cell camping condition comprises that a first value for a theoretical throughput metric at the femto cell is better than a second value for the theoretical throughput metric at the macro cell.

8. The method of claim 1, wherein the femto cell camping condition comprises first voice key performance indicators (KPIs) for the femto cell are better than second voice KPIs for the macro cell.

9. The method of claim 1, wherein the femto cell camping condition comprises that the UE is within a geofence corresponding to the femto cell.

10. The method of claim 1, further comprising: determining that a macro cell de-prioritization termination condition is met; and ending the de-prioritization of the macro cell in response to determining that the macro cell de-prioritization termination condition is met.

11. The method of claim 10, wherein the macro cell de-prioritization termination condition comprises that the UE has moved out of coverage of the femto cell.

12. The method of claim 10, wherein the macro cell de-prioritization termination condition comprises that a first measured signal strength of the macro cell is greater than a second measured signal strength of the femto cell.

13. The method of claim 10, wherein the macro cell de-prioritization termination condition comprises that a threshold number of random access channel (RACH) failures has occurred on the femto cell.

14. The method of claim 10, wherein the macro cell de-prioritization termination condition comprises that a timer associated with the de-prioritization of the macro cell has expired.

15. The method of claim 1, wherein the femto cell comprises a public femto cell.

16. The method of claim 1, wherein the femto cell comprises a private femto cell.

17. A method of a user equipment (UE) that is camped on a femto cell of a network and that has implemented a de-prioritization of a macro cell for cell reselection, comprising: determining that a macro cell de-prioritization termination condition is met; ending the de-prioritization of the macro cell in response to determining that the macro cell de-prioritization termination condition is met; andperforming cell reselection from the femto cell to the macro cell after ending the de-prioritization of the macro cell.

18. The method of claim 17. wherein the macro cell de-prioritization termination condition comprises that the UE has moved out of coverage of the femto cell.

19. The method of claim 17, wherein the macro cell de-prioritization termination condition comprises that a first measured signal strength of the macro cell is greater than a second measured signal strength of the femto cell.

20. The method of claim 17, wherein the macro cell de-prioritization termination condition comprises that a threshold number of random access channel (RACH) failures has occurred on the femto cell.

21. The method of claim 17, wherein the macro cell de-prioritization termination condition comprises that a timer associated with the de-prioritization of the macro cell has expired.

22. The method of claim 17, wherein the femto cell comprises a public femto cell.

23. The method of claim 17, wherein the femto cell comprises a private femto cell.

24. An apparatus comprising means to perform the method of any of claim 1 to claim 23.

25. A computer-readable media comprising instructions to cause an electronic device, upon execution of the instructions by one or more processors of the electronic device, to perform the method of any of claim 1 to claim 23.

26. An apparatus comprising logic, modules, or circuitry to perform the method of any of claim 1 to claim 23.

27. A baseband processor of a user equipment (UE) that is configured to perform the method of any of claim 1 to claim 23.

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