Scheduling cell search and measurement in paging cycles of idle user equipment

Abstract

A user equipment (UE) in a cellular network can estimate a likelihood of a negative performance impact of modifying a duration of a paging cycle for the UE when operating in an idle mode. The UE then selectively modifies the paging cycle based on the estimated likelihood. In some cases, the UE determines the likelihood of the negative performance impact based upon a mobility mode of the UE, such as a stationary mode or a non-stationary mode. In some cases, the UE determines the likelihood of the negative performance impact based upon one or more deployment parameters such as a paging latency.

Description

SCHEDULING CELL SEARCH AND MEASUREMENT IN PAGING CYCLES OF IDLE USER EQUIPMENTBACKGROUND

[0001] The Third Generation Partnership Project (3GPP) defines standards and protocols that govern, among other things, the handover of user equipment between different cells that provide wireless connectivity to the user equipment over an air interface. Examples of the standards defined by the 3GPP include the Fourth Generation Long Term Evolution (4G LTE) and Fifth Generation New Radio (5G NR) standards. User equipment that operates according to these standards can maintain connections with a serving cell in a connected mode or an idle mode. The connected mode is an active state in which the user equipment can communicate directly with the network for data transfer and signaling. The connected mode supports application data exchange and network control tasks such as handovers. In contrast, the idle mode is a low-activity state designed to conserve battery life and manage user equipment mobility without active communication. In this state, the user equipment is not actively engaged in data transfer but can still receive system information and paging messages. Discontinuous reception (DRX) supports two modes - ON and OFF - that allow an idle user equipment to conserve power by sleeping in OFF mode and waking at predetermined intervals to monitor the air interface for messages transmitted by the serving cell in the ON mode. The idle user equipment can search for available cells and perform cell reselection measurements in the ON mode to determine whether to change serving cells.BRIEF DESCRIPTION OF THE DRAWINGS

[0002] The present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. The use of the same reference symbols in different drawings indicates similar or identical items.

[0003] FIG. 1 illustrates a cellular network that supports modifying the length of paging cycles based on a performance impact on idle user equipment, according to some embodiments.

[0004] FIG. 2 illustrates a system model of a wireless communication system such as the cellular network shown in FIG. 1 , according to some embodiments

[0005] FIG. 3 illustrates examples of time intervals for search and cell reselection measurement in sequences of paging cycles having different configured durations, according to some embodiments.

[0006] FIG. 4 illustrates various example operations or processes employed singularly or in various combinations by the paging cycle modification circuitry implemented in the UE, according to some embodiments.

[0007] FIG. 5 illustrates an example device diagram that represents user equipment such as the UE shown in FIG. 1 , according to some embodiments.

[0008] FIG. 6 illustrates a method of selectively scheduling modification or adaptation of paging cycles in an idle UE, according to some embodiments.

[0009] FIG. 7 illustrates a method of determining a scale factor for a modification of the paging cycle based on signal characteristics, according to some embodiments.DETAILED DESCRIPTION

[0010] Network deployments often are configured with a paging cycle that determines when and how often an idle user equipment wakes to listen for signals from its serving cell. For example, the user equipment in a network can be configured with a paging cycle that has one of a set of specified durations, such as 320 milliseconds (ms), 640 ms, 1 .28 seconds, 2.56 seconds, and the like. Networks in many regions, including Europe, Australia, and Canada, deploy networks that are configured with paging cycles of 320 ms. Adopting a relatively short paging cycle increases the amount of energy consumed by user equipment relative to longer paging cycles, which is contrary to the goal of conserving energy by placing the user equipment in the idle mode. For example, user equipment configured with a paging cycle of 320 ms can consume between three and four times as much energy as user equipment configured with a paging cycle of 1 .28 seconds. The increased energy consumption is caused, at least in part, by shorter cycles for decoding paging messages and scheduling cell reselection measurements. In many circumstances,configuring the user equipment with a shorter paging cycle does not improve performance of the user equipment or the mobile-terminated call latency. For example, cell reselection searches and measurements should be completed within the time required for the user equipment to move from a location having a signal-to- interference-plus-noise ratio (SINR) of -3 decibels (dB) to a location having an SINR of -5 dB. For a cell having a radius of 300 meters (m) and a user equipment that moves at a speed of 10 kilometers / hour (km / h), the time available to complete the cell reselection searches / measurements is approximately 12 seconds. Thus, as long as the paging cycle is less than the available time, configuring the user equipment with a short paging cycle incurs a relatively high cost in energy consumption without a corresponding improvement in cell reselection performance.

[0011] FIGs. 1-7 illustrate apparatuses, systems, and methods of reducing the energy consumption of an idle user equipment by modifying the duration of the paging cycle used by the idle user equipment based on an estimated likelihood of a negative performance impact on cell reselection performance of the user equipment. In some embodiments, the performance impact is estimated based on a mobility state of the idle user equipment. The idle user equipment is in a first (stationary or low mobility) mode if the speed or velocity of the user equipment is below an identified threshold, which can depend on deployment parameters of the network such as the typical cell radius. Increasing the duration of the paging cycle is unlikely to have a negative impact on the cell reselection performance of idle user equipment in the first mode. The idle user equipment is in a second (nonstationary or higher mobility) mode if the speed or velocity of the user equipment is above the identified threshold. There is a relatively high likelihood that increasing the duration of the paging cycle will have a negative impact on the cell reselection performance of the idle user equipment in the second mode. The user equipment is therefore configured to use a first (relatively long) paging cycle when the idle user equipment is in the first mode. The UE is configured to use a second (relatively short) paging cycle when the idle user equipment is in the second mode and there is a relatively low likelihood that increasing the duration of the paging cycle will have a negative impact on the cell reselection performance. Other network deployment parameters, such as paging latency requirements, can also be used to determine the likelihood of a negativeimpact on the cell reselection performance. The deployment parameter(s) can be used to select the duration of the paging cycle for the idle user equipment.

[0012] In some implementations, a scale factor is used for scaling the duration of the paging cycle, and this scale factor can be determined based on measurements of signals received from the serving cell. In some embodiments, the scale factor (N) is selected based on threshold values of characteristics of signals received from the serving cell. The characteristics can include an SINR, a reference signal received power (RSRP), a reference signal received quality (RSRQ), and the like. For example, a default or maximum duration (such as 1 .28 seconds) of the paging cycle that determines the scheduling of intra-frequency, inter-frequency, and inter-radio access technology (iRAT) measurements can be scaled by a first value (N=1) if the measured SINR is greater than a first threshold (such as 2 dB). The default duration is scaled (reduced) by a second value (N=2) if the measured SINR is between the first threshold and a second threshold (such as -3 dB) and a third value (N=4) if the measured SINR is below the second threshold. The duration of the paging cycle for the user equipment is then equal to the maximum duration divided by the scale factor, e.g., 1 ,28 / N seconds. A hysteresis associated with the first and second thresholds can be introduced to avoid ping-pong between different scale factors or durations of the paging cycle.

[0013] FIG. 1 illustrates a cellular network 100 (also referred to herein as “network 100” or “communication system 100” or “wireless communication system 100”) that supports modifying the length of paging cycles based on an estimated performance impact on idle user equipment, according to some embodiments. The cellular network 100 includes a device, such as a user equipment (LIE) 102, that is configured to communicate with one or more base stations (BSs) 104 (illustrated as BS 104-1 and BS 104-2) through one or more wireless communication links 106 (illustrated as wireless links 106-1 and 106-2). The BSs 104 can also be referred to as cells. The BSs 104 can be implemented in a macrocell, microcell, small cell, picocell, and the like, or any combination thereof. Examples of base stations 104 include an Evolved Universal Terrestrial Radio Access Network Node B (E-UTRAN Node B), Evolved Node B (eNodeB or eNB), Next Generation (NG or NGEN) Node B (gNode B or gNB), and so on.

[0014] The UE 102 includes one or more components that are configured to implement one or more wireless communication devices, such as a cellular phone, a cellular-enabled tablet computer, a cellular-enabled notebook computer, a cellular- enabled wearable device, an automobile, or other vehicle employing cellular services (e.g., for navigation, provision of entertainment services, in-vehicle mobile hotspots, etc.), and the like. The term “component” is used herein to refer to hardcoded / hardwired circuitry, such as circuitry of an ASIC, programmable circuitry, such as an FPGA, one or more processors executing software / executable instructions, or some combination thereof. In some embodiments, the UE 102 employs a single RAT 108. Some embodiments of the UE 102 are implemented as a multi-mode UE that employs multiple radio access technologies (RATs) 108 (illustrated as RAT 108-1 and RAT 108-2). Examples of multiple RATs include cellular-based RATs, such as a 3GPP Long-Term Evolution (3GPP LTE) RAT, a 3GPP Fifth Generation New Radio (5G NR) RAT, a WLAN RAT, and the like.Although FIG. 1 only shows the UE 102 implementing two different RATs 108, some embodiments of the UE 102 implement three or more different RATs 108. In the illustrated embodiment, one or more RAT modules 110 (illustrated as RAT module 110-1 and RAT module 110-2) manage the RAT s 108 and enable communication between the UE 102 and the radio access technology of the network 100. The one or more RAT modules 110, in some embodiments, include one or more modem chipset(s) of the UE 102, a protocol stack(s), driver software, and the like.

[0015] The BSs 104 communicate with the UE 102 via the wireless links 106, which are implemented using any suitable type of wireless link, standard, or protocol. The wireless links 106, in some embodiments, include a downlink of data and control information communicated from the base stations 104 to the UE 102, an uplink of data and control information communicated from the UE 102 to the BSs 104, or both. In some embodiments, the wireless links 106 (or bearers), such as data radio bearers (DRBs) and signal radio bearers (SRBs), are implemented using any suitable communication protocol or standard, or combination of communication protocols or standards, such as 3GPP 4G LTE, 5G NR, and so on. In some embodiments, multiple wireless links 106 are aggregated in a carrier aggregation to provide a higher data rate for the UE 102. Also, multiple wireless links 106 from multiple BSs 104 are configured, in some embodiments, for coordinated multipoint (CoMP) communicationwith the UE 102, as well as dual connectivity, such as single-RAT LTE-LTE or NR-NR dual connectivity, or multi-radio access technology (Multi-RAT) dual connectivity (MR- DC) including E-UTRA-NR dual connectivity (EN-DC), NGEN radio access network (RAN) E-UTRA-NR dual connectivity (NGEN-DC), and NR E-UTRA dual connectivity (NE-DC).

[0016] The BSs 104 collectively form a Radio Access Network (RAN) 112, such as an E-UTRAN or 5G NR RAN. The base stations 104 are connected to a core network (CN) 114 (illustrated as CN 114-1 and CN 114-2) via control-plane and userplane interfaces through one or more links 116 (illustrated as link 116-1 and link 116- 2). Depending on the configuration of the cellular network 100, the core network 114 is either an Evolved Packet Core (EPC) network 114-1 or a 5G Core Network (5GC) 114-2. For example, in an E-UTRAN configuration or a 5G non-standalone (NSA) EN-DC configuration, the core network 114 is an EPC network 114-1 that includes components such as a Mobility Management Entity (MME) 118, a Serving Gateway (SGW) 120, and a Packet Data Network Gateway (PGW) 122. The MME 118 provides control-plane functions, such as registration and authentication of multiple UEs 102, authorization, mobility management, and so on. The SGW 120 transfers user-plane packets related to audio calls, video calls, Internet traffic, and the like.The PGW 122 provides connectivity from the UE 102 to external packet data networks 124, such as the Internet 126 and an Internet Protocol Multimedia Subsystem (IMS) network 128, by being the point of exit and entry of traffic for the UE 102. In a 5G standalone (SA) configuration or an NSA NE-DC or NGEN-DC configuration, the core network 114 is a 5GC network 114-2. The 5GC 114-2 includes components such as an Access and Mobility Management function (AMF) 130, a User Plane Function (UPF) 132, and a Session Management Function (SMF) 134. The AMF 130 provides control-plane functions such as registration and authentication of multiple UEs 102, authorization, mobility management, and so on. The UPF 132 transfers user-plane packets related to audio calls, video calls, Internet traffic, and the like. The SMF 134 manages protocol data unit (PDU) sessions.

[0017] Some embodiments of the core network 114 communicatively couple the UE 102 to an IMS network 128 via the RAN 112. The IMS network 128 provides various IMS services to the UE 102, such as IMS short messages, IMS unstructuredsupplementary service data (USSD), IMS value-added service data, IMS supplementary service data, IMS voice calls, and IMS video calls. To this end, an entity (e.g., a server or a group of servers) operating in the IMS network 128 supports packet exchange with the UE 102. The packets convey signaling (such as session initiation protocol (SIP) messages, IP messages, or other suitable messages) as well as data (or media), such as voice or video. The IMS network 128 can include entities (not shown) such as a Proxy Call Session Control Function (P-CSCF), an Interrogating Call Session Control Function (l-CSCF), a Serving Call Session Control Function (S-CSCF), a Home Subscriber Server (HSS), a Media Gateway Control Function (MGCF), and the like.

[0018] When in the idle or inactive mode, the UE 102 is associated with a serving cell such as the BS 104-1 . Cells that are proximate the UE 102 but that are not designated as the serving cell, such as the BS 104-2 in the illustrated embodiment, are considered neighboring cells. The serving cell is responsible for monitoring the status of the UE 102, receiving and forwarding messages to the UE 102, receiving messages from the UE 102, and other operations. One function of the serving cell is to page the UE 102 in response to the serving cell receiving information to convey to the UE 102. The serving cell is not generally able to forward information to the UE 102 because the UE 102 does not have an active connection with the serving cell in the idle or inactive modes. Consequently, the UE 102 is configured to periodically wake up and monitor the air interface for signals from the serving cell (such as the BS 104-1) and the serving cell is configured to transmit paging messages to the UE 102 during the configured periodic time interval.

[0019] The cellular network 100 determines when and how often the UE 102 wakes to listen for signals from the serving cell when the UE 102 is in the idle mode. In the illustrated embodiment, the UE 102 and the serving cell (such as the BS 104-1) support DRX when the UE 102 is in the idle or inactive modes. The cellular network 100 specifies the duration of the paging cycles used for DRX. For example, the UE 102 can be configured with a paging cycle that has a duration of 0.32 seconds, 0.64 seconds, 1.28 seconds, 2.56 seconds, and the like. As discussed herein, networks in many regions, including Europe, Australia, and Canada, deploy networks that are configured with paging cycles of 320 ms. The UE 102 monitors the air interface attime intervals determined by the paging cycle. The time intervals are configured as timing windows within the paging cycle that typically remain “open” for conveying information between the serving cell and the LIE 102 during a small fraction of the paging cycle. In some embodiments, the idle UE 102 can search for available cells and perform cell reselection measurements when the timing window is open, e.g., in the ON mode of DRX operation, to determine whether to change serving cells. For example, in the ON mode, the idle UE 102 can search and identify one or neighboring cells (such as the BS 104-2). The idle UE 102 can then perform cell reselection measurements to determine whether to change serving cells, e.g., from the BS 104-1 to the BS 104-2.

[0020] As discussed herein, adopting a relatively short paging cycle (such as 320 ms) increases the amount of energy consumed by the UE 102 relative to longer paging cycles, which is contrary to the goal of conserving energy by placing the UE 102 in the idle mode. To improve the energy efficiency of the UE 102, the UE 102 is configured to estimate a likelihood of a negative performance impact of modifying a duration of a paging cycle for the UE 102 when operating in an idle mode. The UE 102 then selectively modifies the paging cycle based on the likelihood. In the illustrated embodiment, the UE 102 includes a paging cycle modification component 136 configured to modify the paging cycle.

[0021] Some embodiments of the paging cycle modification component 136 determine a mobility mode (such as a stationary mode or a non-stationary mode) based on a speed or velocity of the UE 102. In the illustrated embodiment, the UE 102 includes a stationary mode component 138 configured to store information representing the mobility mode of the UE 102. The UE 102 then estimates the likelihood of the negative performance impact based on the mobility mode. The paging cycle modification component 136 can determine the mobility mode by comparing the speed or velocity to one or more thresholds and selectively modifying the paging cycle can include increasing the duration of the paging cycle in response to the UE 102 being in a first, low mobility, or stationary mode. The UE 102 can determine mobility modes based, in part, on a cell radius, e.g., by implementing one or more thresholds between different mobility modes that are determined based on the cell radius. Some embodiments of the UE 102 estimate the likelihood of thenegative performance impact based on one or more deployment parameters such as a paging latency requirement established by the cellular network 100. As discussed herein, the UE 102 can also consider other factors such as characteristics or qualities of the signal received from the serving cell to determine the duration of the paging cycle. The velocity or speed at which the UE is moving can be estimated using any known technique, such as using accelerometer signals, location signals (e.g., GPS or base station measurements), or other suitable signals to calculate the speed or velocity.

[0022] FIG. 2 illustrates a system model 200 of a wireless communication system such as the cellular network 100 shown in FIG. 1 , according to some embodiments. The system model 200 includes two cells 202, 204 that indicate wireless coverage regions provided by corresponding base stations 206, 208. Although two cells 202, 204 and two corresponding base stations 206, 208 are shown in FIG. 2, more or fewer cells or base stations can be implemented in some embodiments of wireless communication systems. Furthermore, the cells 202, 204 are represented as idealized circular coverage regions having a predetermined radius and the radii of the cells 202, 204 are equal. This idealization is appropriate for the present discussion of the system model 200 but does not typically represent actual coverage regions in deployments of wireless communication systems.

[0023] UE 210 is deployed in the system model 200. In the illustrated embodiment, the UE 210 is in an idle mode and the cell 202 (or the corresponding base station 206) is the serving cell for the idle UE 210. As discussed herein, the idle UE 210 periodically wakes up to search for the serving cell and any neighboring cells and to perform cell reselection measurements to determine whether to remain associated with the current serving cell or select a new serving cell from among the detected neighboring cells. The search and measurements operations are indicated by arrows 212, 214 in FIG. 2. The idle UE 210 is stationary or moving through the cell 202 at a measured speed or velocity. The idle UE 202 measures the SINR of signals transmitted from the serving cell 202 during the cell reselection measurements.

[0024] Short paging cycles can lead to the idle UE 202 performing unnecessary search and cell reselection measurements because it is unlikely that the context of the idle UE 202 will have changed significantly from one paging cycle to the next. Theimpact of changing or modifying the duration of the paging cycles used by the idle LIE 210 can be estimated by comparing the amount of time that elapses as the SINR changes from -3dB to -5dB to the amount of time needed to perform cell reselection from one serving cell to another. For example, in a typical deployment the cell radius is 300m. If the UE 210 moves at 10 km / h, the available time to complete the relevant searches and measurements in preparation for a potential cell reselection is 11.783 s. The available time to complete the relevant searches and measurements typically increases as the cell radius increases and decreases as the speed or velocity of the UE 210 increases.

[0025] FIG. 3 illustrates time intervals for search and cell reselection measurement in sequences 300, 301 , 302, 303 of paging cycles having different configured durations, according to some embodiments. The paging cycles shown in FIG. 1 can be implemented in some embodiments of the cellular network 100 shown in FIG. 1 and the UE 210 in the system model 200 shown in FIG. 2. The sequence 300 includes a paging cycle 304 that has a first duration such as 2.56 seconds, the sequence 301 includes two paging cycles 306 (only one indicated by a reference numeral in the interest of clarity) that have second durations such as 1 .28 seconds, the sequence 302 includes four paging cycles 308 (only one indicated by a reference numeral in the interest of clarity) that have third durations such as 0.64 seconds, and the sequence 303 includes eight paging cycles 310 (only one indicated by a reference numeral in the interest of clarity) that have fourth durations such as 0.32 seconds.

[0026] An idle UE that is configured to wake up according to one of the paging cycles 304, 306, 308, 310 that are illustrated in the sequences 300, 301 , 302, 303, respectively, performs search and cell reselection measurements in predetermined time intervals within the paging cycles 304, 306, 308, 310. For example, an idle UE that is configured according to the paging cycle 304 illustrated in the sequence 300 wakes up during the time interval 312, an idle UE that is configured according to the paging cycle 306 illustrated in the sequence 301 wakes up during the time interval 314, an idle UE that is configured according to the paging cycle 308 illustrated in the sequence 302 wakes up during the time interval 316, and an idle UE that is configured according to the paging cycle 310 illustrated in the sequence 303 wakesup during the time interval 314. The relative sizes of the time intervals 312, 314, 316, 318 and the corresponding paging cycles 304, 306, 308, 310 shown in FIG. 3 do not necessarily correspond to the relative sizes in a deployed wireless communication system. However, the relative numbers of time intervals 312, 314, 316, 318 in the sequences 300, 301 , 302, 303, respectively, indicates the relative consumption of resources (such as energy) by idle UE performing search / measurement when configured to use the corresponding paging cycles 304, 306, 308, 310 shown in FIG. 3.

[0027] FIG. 4 illustrates various example operations or processes employed singularly or in various combinations by the paging cycle modification component 136 implemented in the UE 102, according to some embodiments. In some embodiments, these operations include device state and cellular information procurement 402, stationary confidence ranking 404, stationary condition evaluation 406, and parameters that represent aspects of deployment 408. Examples of these operations are discussed in co-pending application PCT / US2024 / 031638, filed on May 30, 2024 and entitled “Device-Assisted Stationary Mode,” which is incorporated herein by reference in its entirety. For device state and cellular information procurement 402, the paging cycle modification component 136 obtains device state information 410 and cellular information 412 from the UE 102. Examples of the device state information 410 include state or status information of: one or more device batteries; one or more thermal sensors; one or more displays; VoWiFi connectivity; WLAN connectivity; combinations thereof; and the like. Examples of cellular information 412 include radio frequency (RF) metrics, such as SINR, RSRP, SINR / RSRP slope estimation, and the like.

[0028] For stationary confidence ranking 404, the paging cycle modification component 136 uses the device state information 410 to generate a stationary confidence rank 414, also referred to herein as “stationary confidence rank 414”, indicating a probability that the assessment of the UE 102 being in a stationary state is accurate. The paging cycle modification component 136 selects, based on the stationary confidence rank 414, a set of stationary mode conditions 416 (also referred to herein as “conditions 416”) from a plurality of stationary conditions to evaluate for placing the UE 102 into one of a plurality of stationary modes 138. Depending on thestationary confidence rank 414, the paging cycle modification component 136 selects a different set of stationary mode conditions 416 for each of the stationary modes 138. Stated differently, different conditions 416 are selected for the same stationary mode 138 depending on the stationary confidence rank 414.

[0029] During stationary condition evaluation 406, the paging cycle modification component 136 evaluates the stationary mode conditions 416 that were selected based on the stationary confidence rank 414. The stationary mode conditions 416, in some embodiments, include mobility conditions 416-1 (e.g., still mobility conditions and low mobility conditions) and cell edge level conditions 416-2 (e.g., cell edge conditions, first level non-cell edge conditions, and second level non-cell edge conditions). Therefore, stationary condition evaluation 406 includes one or more suboperations or processes, such as a device mobility detection 406-1 and a cell edge level detection 406-2. As part of device mobility detection 406-1 , the paging cycle modification component 136 determines if a mobility condition 416-1 is satisfied based on, for example, the cellular information 412 such as SINR, RSRP, SINR / RSRP slope estimation, and the like. For example, a still mobility condition, in some embodiments, is satisfied when the UE 102 has a relative RSRP change of a first threshold (e.g., 3 dB), and a low mobility condition, in some embodiments, is satisfied when the UE 102 has a relative RSRP change of a second threshold (e.g., 5 dB) that is greater than the first threshold. A relative RSRP change is the difference between the current RSRP and the average RSRP. Other RSRP threshold values are applicable as well. In some embodiments, the paging cycle modification component 136 also uses sensor information, such as accelerometer information or gyroscope information, to determine if a mobility condition has been satisfied.

[0030] As part of cell edge level detection 406-2, the paging cycle modification component 136 determines if a cell edge level condition 416-2 is satisfied based on, for example, cellular information 412, such as SINR. For example, the cell edge level conditions 416-2 include a cell edge condition having a first SINR threshold, a first non-cell edge level condition having a second SINR threshold greater than the first SINR threshold, and a second non-cell edge level condition having a third SINR threshold greater than the second SINR threshold.

[0031] During deployment 408, the paging cycle modification component 136 places the UE 102 into one of a plurality of stationary modes 138, each being configured to apply a different set of modifications to a paging cycle, which are referred to herein as “DRX modifications 218.” For example, the paging cycle modification component 136 places the UE 102 into a full stationary mode 438-1 or a partial stationary mode 438- 2 based on evaluating the stationary mode conditions 416. In some embodiments, the full stationary mode 438-1 configures the UE 102 with a first set of DRX modifications 418-1 , such as increasing a paging cycle by applying a first scale factor to a default paging cycle duration. In some embodiments, the partial stationary mode configures the UE 102 with a second set of DRX modifications 418-2, such as increasing a paging cycle by applying a second scale factor to a default paging cycle duration, the second scale factor being smaller than the first scale factor so that the paging cycle in the second set of DRX modifications 418-2 is longer than the paging cycle in the first set of DRX modifications 418-1.

[0032] FIG. 5 illustrates an example device diagram 500 that represents user equipment such as the UE 102 shown in FIG. 1 , according to some embodiments. The device diagram 500 illustrates a UE that implements the device-assisted stationary modes and paging cycle modification techniques described herein. The UE 102 may include additional functions and interfaces that are omitted from FIG. 5 for the sake of clarity. The UE 102, in some embodiments, includes antennas 502, a radio frequency (RF) front end 504, and one or more RF transceivers 506 (e.g . , a 3GPP 4G LTE transceiver 506-1 and a 3G NR transceiver 506-2) for communicating with one or more base stations 104 in a RAN 112, such as a 3G RAN, an E-UTRAN, a combination thereof, and so on. In some embodiments, the RF transceivers 506 are RF modems, and thus are also referred to herein as “RF modem 506”. The RF front end 504, in some embodiments, includes a transmitting (Tx) front end 504-1 and a receiving (Rx) front end 504-2. The Tx front end 504-1 includes components such as one or more power amplifiers (PA), drivers, mixers, filters, and so on. The Rx front end 504-2 includes components such as low-noise amplifiers (LNAs), mixers, filters, and so on. The RF front end 504, in some embodiments, couples or connects the one or more RF transceivers 506, such as the LTE transceiver 506-1 and the 3G NR transceiver 506-2, to the antennas 502 to facilitate various types of wireless communication.

[0033] In some embodiments, the antennas 502 of the UE 102 include an array of multiple antennas configured similarly to or different from each other. The antennas 502 and the RF front end 504, in some embodiments, are tuned to or are tunable to one or more frequency bands, such as those defined by the 3GPP LTE, 3GPP 3G NR, IEEE wireless local area network (WLAN), IEEE wireless metropolitan area network (WMAN), or other communication standards. In some embodiments, the antennas 502, the RF front end 504, the LTE transceiver 506-1 , and the 3G NR transceiver 506-2 are configured to support beamforming (e.g., analog, digital, or hybrid) or in-phase and quadrature (l / Q) operations (e.g., I / Q modulation or demodulation operations) for the transmission and reception of communications with one or more base stations 104. By way of example, the antennas 502 and the RF front end 504 operate in sub-gigahertz bands, sub-6 GHz bands, above 6 GHz bands, or a combination of these bands defined by the 3GPP LTE, 3GPP 3G NR, or other communication standards.

[0034] In some embodiments, the antennas 502 include one or more receiving antennas positioned in a one-dimensional shape (e.g., a line) or a two-dimensional shape (e.g., a triangle, a rectangle, or an L-shape) for implementations that include three or more receiving antenna elements. While the one-dimensional shape enables the measurement of one angular dimension (e.g., an azimuth or an elevation), the two-dimensional shape enables two angular dimensions to be measured (e.g., both azimuth and elevation). Using at least a portion of the antennas 502, the UE 102 can form beams that are steered or un-steered, wide or narrow, or shaped (e.g., as a hemisphere, cube, fan, cone, or cylinder). The one or more transmitting antennas may have an un-steered omnidirectional radiation pattern or may produce a wide steerable beam. Either of these techniques enables the UE 102 to transmit a radio signal to illuminate a large volume of space. In some embodiments, the receiving antennas generate thousands of narrow steered beams (e.g., 2000 beams, 4000 beams, or 6000 beams) with digital beamforming to achieve desired levels of angular accuracy and angular resolution.

[0035] The UE 102, in some embodiments, includes one or more sensors 508 implemented to detect various properties such as one or more of temperature,supplied power, power usage, battery state, and the like. Examples of sensors include a thermal sensor, a battery sensor, a power usage sensor, and so on.

[0036] The UE 102 also includes at least one processor 510. The processor 510, in some embodiments, is a single-core processor or a multiple-core processor composed of a variety of materials, such as silicon, polysilicon, high-K dielectric, copper, and so on. In some embodiments, the processor 510 is implemented at least partially in hardware, including, for example, components of an integrated circuit or a system-on-a-chip (SoC), a digital-signal-processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a complex programmable logic device (CPLD), other implementations in silicon or other hardware, or a combination thereof.

[0037] Examples of the processor(s) 510 include a communication processor, an application processor, microprocessors, DSPs, controllers, and so on. A communication processor, in some embodiments, is implemented as a modem baseband processor, software-defined radio module, configurable modem (e.g., multi-mode, multi-band modem), wireless data interface, wireless modem, or so on. In some embodiments, a communication processor supports one or more of data access, messaging, or data-based services of a wireless network, as well as various audio-based communication (e.g., voice calls). An application processor, in some embodiments, provides computing resources to applications executing on the UE 102. For example, an application provides a self-contained operating environment that delivers system capabilities (e.g., graphics processing, memory management, and multimedia processing) to support applications executing on the UE 102.

[0038] The UE 102 further includes a non-transitory computer-readable storage medium 512 (CRM 512). The computer-readable storage media described herein excludes propagating signals. The CRM 512, in some embodiments, includes any suitable memory or storage device such as random-access memory (RAM), static RAM (SRAM), dynamic RAM (DRAM), non-volatile RAM (NVRAM), read-only memory (ROM), or Flash memory useable to store device data 514 of the UE 102. In some embodiments, the device data 514 includes user data, multimedia data, beamforming codebooks, applications 516, a user interface(s) 518, an operating system of the UE 102, and so on, which are executable by the processor(s) 510 toenable user-plane communication, control-plane signaling, and user interaction with the UE 102. The user interface 518, in at least one embodiment, is configured to receive inputs from a user of the UE 102. In some embodiments, the user interface 518 includes a graphical user interface (GUI) that receives the input information via a touch input. In other instances, the user interface 518 includes an intelligent assistant that receives the input information via an audible input or speech. Alternatively, or additionally, the operating system of the UE 102 is maintained as firmware or an application on the CRM 512 and executed by the processor(s) 510.

[0039] The CRM 512, in some embodiments, further includes one or more of the device state information 520, cellular information 522, stationary confidence ranks 524, stationary mode conditions 526, station mode configurations 528, and paging cycle modifications 530. The CRM 512 further includes either or both of a communication manager 532 and a stationary mode manager 534. Alternatively, or additionally, either or both of the communication manager 532 and the stationary mode manager 534, in some embodiments, are implemented in whole or part as hardware logic or circuitry integrated with or separate from other components of the UE 102. In some embodiments, the communication manager 532 configures the RF front end 504, the LTE transceiver (modem) 506-1 , the 3G NR transceiver (modem) 506-2, or a combination thereof, to perform one or more wireless communication operations. The stationary mode manager 534, in some embodiments, implements the paging cycle modifications 136 described above with respect to FIG. 1 and FIG. 2 to detect when the UE is in a stationary state (e.g., still or moving at a walking speed or velocity) and employs one or more stationary modes 138 during which RRM activities are reduced for conserving energy at the UE 102. In some embodiments, the stationary mode manager 534 implements the paging cycle modifications 136 or one or more of the operations described herein in response to the UE 102 being in an inactive state, such as a Radio Resource Control (RRC) idle state.

[0040] FIG. 6 illustrates a method 600 of selectively scheduling modification or adaptation of paging cycles in an idle UE, according to some embodiments. The method 600 is implemented in some embodiments of the UE 102 shown in FIG. 1. Some embodiments of the method 600 are iterated or repeated for each paging cyclesuch as a DRX paging cycle that is implemented in the idle LIE. However, the method 600 can be iterated or repeated at different time intervals in other embodiments.

[0041] At block 602, the UE is camped on a serving cell in idle mode. The UE is configured to operate using a paging cycle that indicates periodic intervals for waking and performing actions such as searching for neighboring cells and performing cell reselection measurements of signals from the serving cell and neighboring cells. In some embodiments, the paging cycle is determined according to DRX configuration information. For example, the DRX cycle can be one of a plurality of cycles such as 2.56 seconds, 1.28 seconds 0.64 seconds, and 0.32 seconds. The method 600 then flows to the block 604, e.g., in response to a predetermined time interval elapsing such as reaching the end (or a specified time within) the paging cycle.

[0042] At decision block 604, the UE determines its mobility state or mode. In some embodiments, the UE determines whether it is in a stationary mode or a non- stationary mode. The mobility modes can also include additional mobility modes such as a full stationary mode in which the UE is moving at a speed or velocity that is lower than a first threshold and a partial stationary mode in which the UE is moving at a speed or velocity that is higher than the first threshold and lower than a second threshold that is greater than the first threshold. Although the UE considers (at the decision block 604) the mobility state or mode to determine the impact on the UE performance of modifying the paging cycle, some embodiments of the UE can consider (at the decision block 604) other criteria that determine, at least in part, the likelihood of a negative performance impact from modifying the UE paging cycle. For example, the UE can consider (at the decision block 604) one or more deployment parameters such as paging latency requirements.

[0043] If the UE determines (at decision block 604) that it is in the stationary mode, and the impact on performance is small or negligible or insignificant, the method 600 flows to the block 606. Otherwise, if the UE determines that it is not in the stationary mode, and the impact on performance due to a modification or adaptation of scheduling in the paging cycle is potentially large or significant, the method 600 flows back to the block 602 so that the UE remains in the current scheduling state with the previously configured paging cycle.

[0044] At block 606, the UE performs a scheduling adaptation and coordination with the network. For example, if the UE is in a first stationary mode, such as a full stationary mode, the paging cycle is modified by increasing the duration of the paging cycle to a predetermined duration such as 1 .28 seconds. For another example, if the UE is in a second stationary mode, such as a partial stationary mode, the paging cycle is modified by increasing the duration of the paging cycle to a different (shorter) predetermined duration such as 0.64 seconds or 0.32 seconds. In some embodiments, the paging cycle is modified based on characteristics of the signals received from the serving cell such as a SINR. Modifications to the paging cycle can be implemented by applying a scale factor to a predetermined or default duration such as 1.28 seconds or 2.56 seconds. For example, the duration of the paging cycle for the UE can be set to a value equal to the predetermined or default duration divided by the scale factor, e.g., 1 ,28 / N seconds, where N is the scale factor.

[0045] FIG. 7 illustrates a method 700 of determining a scale factor for a modification of the paging cycle based on signal characteristics, according to some embodiments. The method 600 is implemented in some embodiments of the UE 102 shown in FIG. 1 and some embodiments of the block 604 shown in FIG. 6.

[0046] At block 702, the UE determines a signal characteristics based on measurements of signals received by cells including the serving cell and one or more neighboring cells. In the illustrated embodiment, the characteristic is a SINR. However, in other embodiments other characteristics can be used such as a SNR, RSRP, RSRQ, other characteristics, or combinations of these characteristics.

[0047] At decision block 704, the UE determines whether the measured value of the characteristic is greater than a first threshold. For example, the UE can compare the measured value of the SINR to a first threshold SINR value such as 2 decibels (dB). If the measured value is greater than the first threshold, the method 700 flows to the block 706. If the measured value is less than the first threshold, the method 700 flows to the decision block 708. Persons of ordinary skill in the art should appreciate that some embodiments of the method 700 can use different comparisons for different characteristics. For example, if appropriate, the UE may flow from the decision block 704 to the block 706 if a measured value of a different characteristic is less than the first threshold.

[0048] At block 706, the UE sets the scaling factor to N=1 so that UE uses the predetermined or default value of the duration of the paging cycle. For example, if the UE measures an SI NR of signals received from the serving cell that is greater than 2 dB, the UE is configured to use the (relatively long) predetermined or default paging cycle duration.

[0049] At decision block 708, the UE determines whether the measured value of the characteristic is greater than a second threshold. The second threshold is less than the first threshold. For example, the UE can compare the measured value of the SINR to a second threshold SINR value such as -3 dB. If the measured value is greater than the second threshold, the method 700 flows to the block 710. If the measured value is less than the second threshold, the method 700 flows to the block 712. Persons of ordinary skill in the art should appreciate that some embodiments of the method 700 can use different comparisons for different characteristics. For example, if appropriate, the UE may flow from the decision block 708 to the block 710 if a measured value of a different characteristic is less than the second threshold.

[0050] At block 710, the UE sets the scale factor to N=2 so that the UE implements a paging cycle that has a duration that is half the predetermined or default duration. For example, if the UE measures an SINR of signals received from the serving cell that is in the range of 2 dB > SINR > -3 dB, the UE is configured to use a paging cycle that has a duration that is half the predetermined or default paging cycle duration.

[0051] At block 712, the UE sets the scale factor to N=4 so that the UE implements a paging cycle that has a duration that is one quarter of the predetermined or default duration. For example, if the UE measures an SINR of signals received from the serving cell that is less than -3 dB, the UE is configured to use a (relatively short) paging cycle that has a duration that is one quarter of the predetermined or default paging cycle duration.

[0052] In some embodiments, a hysteresis is included in the first threshold and second threshold. The hysteresis can be determined based on the current value of the scale factor. For example, the first threshold can have a first value if the current value of the scale factor is N=1 and a second value (different than the first value) ifthe current value of the scale factor is N 1. For another example, the second threshold can have a first value if the current value of the scale factor is N=2 and a second value of the current value of the scale factor is N 2. Other techniques for determining the hysteresis that is applied to the first and second thresholds can be used in other embodiments.

[0053] In some embodiments, certain aspects of the techniques described above may be implemented by one or more processors of a processing system executing software. The software comprises one or more sets of executable instructions stored or otherwise tangibly embodied on a non-transitory computer readable storage medium. The software can include the instructions and certain data that, when executed by the one or more processors, manipulate the one or more processors to perform one or more aspects of the techniques described above. The non-transitory computer readable storage medium can include, for example, a magnetic or optical disk storage device, solid state storage devices such as Flash memory, a cache, random access memory (RAM) or other non-volatile memory device or devices, and the like. The executable instructions stored on the non-transitory computer readable storage medium may be in source code, assembly language code, object code, or other instruction format that is interpreted or otherwise executable by one or more processors.

[0054] A computer readable storage medium may include any storage medium, or combination of storage media, accessible by a computer system during use to provide instructions and / or data to the computer system. Such storage media can include, but is not limited to, optical media (e.g., compact disc (CD), digital versatile disc (DVD), Blu-Ray disc), magnetic media (e.g., floppy disc , magnetic tape, or magnetic hard drive), volatile memory (e.g., random access memory (RAM) or cache), non-volatile memory (e.g., read-only memory (ROM) or Flash memory), or microelectromechanical systems (MEMS)-based storage media. The computer readable storage medium may be embedded in the computing system (e.g., system RAM or ROM), fixedly attached to the computing system (e.g., a magnetic hard drive), removably attached to the computing system (e.g., an optical disc or Universal Serial Bus (USB)-based Flash memory), or coupled to the computer system via a wired or wireless network (e.g., network accessible storage (NAS)).

[0055] Note that not all of the activities or elements described above in the general description are required, that a portion of a specific activity or device may not be required, and that one or more further activities may be performed, or elements included, in addition to those described. Still further, the order in which activities are listed are not necessarily the order in which they are performed. Also, the concepts have been described with reference to specific embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present disclosure as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present disclosure.

[0056] Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims. Moreover, the particular embodiments disclosed above are illustrative only, as the disclosed subject matter may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. No limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope of the disclosed subject matter. Accordingly, the protection sought herein is as set forth in the claims below.

Claims

WHAT IS CLAIMED IS:1 . A method at a user equipment (UE) in a cellular network, comprising: estimating a likelihood of a negative performance impact of modifying a duration of a paging cycle for the UE when operating in an idle mode; and selectively modifying the paging cycle based on the estimated likelihood.

2. The method of claim 1 , wherein estimating the likelihood of the negative performance impact comprises: determining a mobility mode of the UE based on an estimated speed at which the UE is moving; and estimating the likelihood of the negative performance impact based on the mobility mode.

3. The method of claim 2, wherein determining the mobility mode of the UE comprises: determining whether the UE is in a first mobility mode or a second mobility mode based on the estimated speed of the UE.

4. The method of claim 3, wherein determining whether the UE is in the first mobility mode or the second mobility mode comprises: determining that the UE is in the first mobility mode in response to the estimated speed of the UE being below a threshold; and determining that the UE is in the second mobility mode in response to the estimated speed of the UE being above the threshold.

5. The method of claim 4, further comprising: determining a value of the threshold that indicates a low likelihood of the negative performance impact when the UE is in the first mobility mode.

6. The method of claim 5, wherein determining the value of the threshold comprises determining the value of the threshold based on a cell radius of the serving cell.

7. The method of claim 3, wherein selectively modifying the paging cycle comprises increasing the paging cycle in response to the UE being in the first mobility mode.

8. The method of claim 1 , wherein estimating the likelihood of the negative performance impact comprises: estimating the likelihood based on at least one deployment parameter associated with the UE.

9. The method of claim 8, wherein the at least one deployment parameter comprises at least one paging latency requirement.

10. The method of claim 1 , further comprising: measuring at least one value of at least one characteristic of signals received from a serving cell over an air interface between the UE and the serving cell.11 . The method of claim 10, further comprising: determining a scale factor for a duration of the paging cycle based on the at least one value of the at least one characteristic.

12. The method of claim 11 , wherein the at least one characteristic of the signals received from the serving cell comprises at least one of a signal-to-interference-plus- noise ratio (SINR), a reference signal received power (RSRP), or a reference signal received quality (RSRQ).

13. The method of claim 11 , wherein selectively modifying the paging cycle comprises: reducing a duration of the paging cycle using a first value for the scale factor if the at least one value is greater than a first threshold, using a second value for the scale factor if the at least one value is less than the first threshold and greater than a second threshold, and using a third value for the scale factor if the at least one value is less than the second threshold, and wherein the first value is less than the second value and the second value is less than the third value.

14. The method of claim 13, further comprising: modifying at least one of the first threshold and the second threshold to introduce a hysteresis for determining the scale factor.

15. A user equipment (UE) (102), comprising: one or more radio frequency (RF) modems (306) configured to wirelessly communicate with at least one network (100); one or more processors (310) coupled to the one or more RF modems; and at least one memory (312) storing executable instructions, the executable instructions configured to manipulate at least one of the one or more processors or the one or more RF modems to perform the method of any of the preceding claims.

16. A computer-readable storage medium embodying a set of executable instructions, the set of executable instructions to manipulate a UE to perform the method of any of claims 1 to 14.

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