WO2021226952A1

WO2021226952A1 - Prompting wireless service reconnection based on signal change condition

Info

Publication number: WO2021226952A1
Application number: PCT/CN2020/090325
Authority: WO
Inventors: Yi Liu; Jinglin Zhang; Haojun WANG; Zhenqing CUI; Yuankun ZHU; Fojian ZHANG; Hao Zhang; Jian Li; Hong Wei
Original assignee: Qualcomm Incorporated
Priority date: 2020-05-14
Filing date: 2020-05-14
Publication date: 2021-11-18

Abstract

This disclosure provides systems, methods, and apparatus, including computer programs encoded on computer-readable media, for a UE to prompt a wireless service reconnection based on signal change condition. The UE may establish a Long-Term Evolution (LTE) connection after losing a 5G New Radio (NR) connection in an environment (for example, an elevator) associated with interfering with the 5G NR connection. The UE may monitor a measured LTE signal quality associated with the LTE connection. When the UE detects the increase in measured LTE signal quality, the UE may send a message to the LTE network to cause the LTE network to initiate a network handover procedure so that the UE can establish a new connection to the 5G NR network.

Description

PROMPTING WIRELESS SERVICE RECONNECTION BASED ON SIGNAL CHANGE CONDITION

TECHNICAL FIELD

Aspects of the present disclosure generally relate to wireless communication and a user equipment (UE) prompting a wireless service reconnection based on a signal change condition.

DESCRIPTION OF THE RELATED TECHNOLOGY

Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (for example, time, frequency, and power) . A wireless communication system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE) . Different base stations or network access nodes may implement different radio communication protocols including fourth-generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth-generation (5G) systems which may be referred to as New Radio (NR) systems. NR, which also may be referred to as 5G for brevity, is a set of enhancements to the LTE mobile standard promulgated by the Third Generation Partnership Project (3GPP) .

A UE may be configured to establish a connection to a 5G NR network as a stand-alone connection. Occasionally, the 5G NR signal quality may deteriorate below an acceptable signal quality. For example, the UE may enter an environment (such as an elevator, underground tunnel, building, parking structure, sports venue, or vehicle, among other examples) that causes the 5G NR signal quality to deteriorate. Typically, the UE will establish an alternative connection to another network such as an LTE network. However, it is desirable for the UE to reestablish the connection to the 5G NR network after leaving such environment. Traditional techniques for reestablishing the connection to the 5G NR network may be slow or inefficient.

SUMMARY

The systems, methods, and devices of this disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

One innovative aspect of the subject matter described in this disclosure can be implemented in a method of wireless communication performed by an apparatus for use in a user equipment (UE) . The method may include determining that the UE has lost a first connection to a 5G New Radio (NR) network. The method may include establishing a second connection to a Long-Term Evolution (LTE) network in response to losing the first connection. The method may include monitoring a measured LTE signal quality associated with the second connection. The method may include, in response to detecting an increase in the measured LTE signal quality above a threshold amount, outputting a measurement report for transmission to the LTE network to cause the LTE network to initiate a network handover procedure so that the UE can establish a new connection to the 5G NR network.

In some implementations, the method may include determining that the UE has lost the first connection to the 5G NR network as a result of the UE entering an environment. The increase in the measured LTE signal quality being above the threshold amount may be indicative that the UE has left the environment.

In some implementations, the environment may be an elevator, underground tunnel, building, parking structure, sports venue, or vehicle.

In some implementations, the measured LTE signal quality is a metric based on at least one member selected from a group consisting of a reference signal received power (RSRP) , a reference signal received quality (RSRQ) , and a received signal strength indicator (RSSI) .

In some implementations, detecting that the increase in the measured LTE signal quality is above the threshold amount may include determining a rate of change in the measured LTE signal quality over time. The method may include detecting that the increase in the measured LTE signal quality is above the threshold amount when the rate of change is above the threshold amount.

In some implementations, detecting that the increase in the measured LTE signal quality is above the threshold amount may include determining a first average LTE signal quality based on the measured LTE signal quality over a first time period. The method may include determining a second average LTE signal quality based on the measured LTE signal quality over a second time period following the first time period. The method may include determining that a difference between the second average LTE signal quality and the first average LTE signal quality is above the threshold amount.

In some implementations, the first time period is 5 seconds and the second time period is 5 seconds immediately following the first time period, and wherein the threshold amount is a change of 15 decibels (dB) between the first average LTE signal quality and the second average LTE signal quality.

In some implementations, the measurement report may include a reported LTE signal quality that is lower than the actual measured LTE signal quality.

In some implementations, the reported LTE signal quality may be below a threshold configuration value associated with triggering the network handover procedure.

In some implementations, the method may include determining that a measurement reporting event (A2 event) and an A2 event threshold are configured for the second connection. The A2 event threshold may be associated with triggering the network handover procedure. In some implementations, sending the measurement report to the LTE network may include sending an A2 event report with a reported LTE signal quality that is lower than the A2 event threshold regardless of whether the measured LTE signal quality is lower than the A2 event threshold.

In some implementations, the method may include temporarily suppressing a 5G NR measurement procedure in response to establishing the second connection to the LTE network. The method may include resuming the 5G NR measurement procedure after detecting the increase in the measured LTE signal quality above the threshold amount.

Another innovative aspect of the subject matter described in this disclosure can be implemented as a UE. The UE may include an interface and a processor configured to perform any one of the above-mentioned methods.

Another innovative aspect of the subject matter described in this disclosure can be implemented as a computer-readable medium having stored therein instructions which, when executed by a processor, causes the processor to perform any one of the above-mentioned methods.

Another innovative aspect of the subject matter described in this disclosure can be implemented as a system having means for implementing any one of the above-mentioned methods.

Details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings, and the claims. Note that the relative dimensions of the following figures may not be drawn to scale.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a pictorial diagram conceptually illustrating an example of a wireless network.

Figure 2 shows a block diagram conceptually illustrating an example of a base station in communication with a user equipment (UE) in a wireless network.

Figure 3 shows a block diagram conceptually illustrating an example of a frame structure in a wireless network.

Figure 4 shows a block diagram conceptually illustrating an example of a UE that can establish a Long-Term Evolution (LTE) connection or a 5G New Radio (NR) connection.

Figure 5 shows a block diagram conceptually illustrating an example of a UE that changes connections as it moves in and out of an environment that causes a decrease in signal quality.

Figure 6 shows a timing diagram conceptually illustrating example signal quality and connections over time.

Figure 7 shows a timing diagram conceptually illustrating an example of changes in average signal quality that trigger a network handover.

Figure 8 shows a flowchart illustrating an example process for prompting wireless service reconnection based on signal change condition according to some implementations.

Figure 9 shows a conceptual diagram of an example message to trigger a wireless service reconnection according to some implementations.

Figure 10 shows a flowchart illustrating a detailed example process for reestablishing a 5G NR connection based on a rapid increase in LTE signal quality according to some implementations.

Figure 11 shows a block diagram of an example wireless communication device.

Like reference numbers and designations in the various drawings indicate like elements.

DETAILED DESCRIPTION

The following description is directed to certain implementations for the purposes of describing the innovative aspects of this disclosure. However, a person having ordinary skill in the art will readily recognize that the teachings herein can be applied in a multitude of different ways. Some of the examples in this disclosure are based on wireless and wired local area network (LAN) communication according to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 wireless standards, the IEEE 802.3 Ethernet standards, and the IEEE 1901 Powerline communication (PLC) standards. However, the described implementations may be implemented in any device, system or network that is capable of transmitting and receiving radio frequency signals according to any of the wireless communication standards, including any of the IEEE 802.11 standards, the

standard, code division multiple access (CDMA) , frequency division multiple access (FDMA) , time division multiple access (TDMA) , Global System for Mobile communications (GSM) , GSM/General Packet Radio Service (GPRS) , Enhanced Data GSM Environment (EDGE) , Terrestrial Trunked Radio (TETRA) , Wideband-CDMA (W-CDMA) , Evolution Data Optimized (EV-DO) , 1xEV-DO, EV-DO Rev A, EV-DO Rev B, High Speed Packet Access (HSPA) , High Speed Downlink Packet Access (HSDPA) , High Speed Uplink Packet Access (HSUPA) , Evolved High Speed Packet Access (HSPA+) , Long Term Evolution (LTE) , AMPS, or other known signals that are used to communicate within a wireless, cellular or internet of things (IOT) network, such as a system utilizing 3G, 4G or 5G, or further implementations thereof, technology.

A wireless communication network may include a number of base stations (BSs) that can support communication for a number of user equipment (UEs) . A user equipment (UE) may communicate with a base station (BS) via the downlink (DL) and uplink (UL) . The DL (or forward link) refers to the communication link from the BS to the UE, and the UL (or reverse link) refers to the communication link from the UE to the BS. A wireless communication session or association between the UE and a BS may be referred to as a radio connection (or just a “connection” ) . Different types of base stations may be referred to as a NodeB, an LTE evolved nodeB (eNB) , a gNB, an access point (AP) , a radio head, a transmit receive point (TRP) , a New Radio (NR) BS, a 5G NodeB, among other examples, depending on the wireless communication standard that the base station supports. One or more LTE base stations may make up an LTE radio access network (RAN) , and may be referred to as an LTE RAN or LTE network that provides access to the wireless communication network. Similarly, one or more 5G base stations may make up a 5G New Radio (NR) RAN, and may be referred to as a 5G NR network that provides access to the wireless communication network. The LTE network and 5G NR network may be two examples of a radio access network that can be used to communicate to a core network of the wireless communication network. Legacy networks (such as 2G or 3G networks) also may provide access to the wireless communication network. A standalone (SA) connection may refer to a connection in which the initial acquisition and connection are made between the UE and the RAN. A non-standalone (NSA) connection may refer to a secondary connection which is established after a primary connection is anchored to a different RAN. For brevity, the examples in this disclosure refer to SA connections.

As 5G networks are deployed, it is expected that coverage may be less ubiquitous than other network options, such as LTE or legacy networks. For example, LTE coverage may be more widely available and may penetrate some locations that are not reachable by a 5G NR RAN. Typically, when a UE loses a 5G NR connection, the UE may establish an LTE connection. In some deployments, the LTE network may not configure a measurement configuration that permits the UE to periodically measure 5G signal quality. Thus, there is a potential that the UE may remain in the LTE connected mode even when a 5G NR network becomes available.

This disclosure provides systems, methods, and apparatus, including computer programs encoded on computer-readable media, for a UE to prompt a wireless service reconnection based on signal change condition. For example, the UE may prompt the network to configure a 5G NR measurement or network handover when the UE determines that it has exited an environment that caused a previous change from a 5G NR connection to an LTE connection. In some implementations, the UE may establish an LTE connection after losing a 5G NR connection. The UE may monitor a measured LTE signal quality associated with the LTE connection. A rapid increase in the measured LTE signal quality may be indicative that the UE has left the environment that originally caused the UE to lose the 5G NR connection. When the UE detects the increase in measured LTE signal quality, the UE may send a message to the LTE network to cause the LTE network to initiate a network handover procedure so that the UE can establish a new connection to the 5G NR network. For example, the UE may send a measurement report with a falsified reported LTE signal quality to prompt the network to initiate the network handover procedure sooner than would otherwise occur.

Several examples in this disclosure are based on a scenario in which the UE enters or exits an elevator. However, the techniques are applicable to any environment which may temporarily impact signal quality for a 5G NR connection. Example environments that impact signal quality may include an elevator, a vehicle, a building, a parking structure, a sports venue, an underground tunnel, or a subway, among other examples. The techniques in this disclosure enable a UE to determine when the UE has exited such an environment based on a signal quality. The signal quality may be a reference signal received power (RSRP) , a reference signal received quality (RSRQ) , or a received signal strength indicator (RSSI) , among other examples. In some implementations, the UE may observe an increase in signal quality and infer that the UE has left an environment that was causing a decrease in signal quality. For example, the UE may monitor signal quality for a rapid increase, such as a rate of increase above a threshold, to infer that the UE has left an elevator. Alternatively, or additionally, the UE may monitor for patterns in signal quality that can be used to infer when the UE enters and exits particular environments such as an elevator.

This disclosure also provides techniques for a UE to prompt a network handover so that the UE can more quickly return to a 5G NR connection after leaving the environment. Typically, the network to which the UE is connected will manage when and how the UE will perform a network handover. However, in accordance with some implementations of this disclosure, a UE may prompt the network to initiate a network handover based on a measurement reporting event. A network connection may have a measurement configuration that defines measurement gap time periods for the UE to perform a measurement procedure. The measurement procedure is used by the UE to conduct measurements of base station signals to determine whether a change to the radio connection is warranted. According to the measurement configuration, the UE may be configured to periodically perform measurements to determine whether the connection should change to a different base station. In some implementations, an LTE network may configure a measurement configuration that includes measurement gap time periods for the UE to measure 5G NR signal quality. The measurement procedure includes temporarily suspending communication via the LTE connection during the measurement gap time period. Thus, the UE may not communicate with the LTE network during the measurement gap time period so that the UE can obtain measurements of potential 5G NR base stations.

An example measurement configuration may include a threshold-based measurement reporting event (A2 event) . The A2 event is typically configured by the eNB to define when the UE should perform the measurement procedure and send an A2 measurement report back to the eNB. In some implementations of this disclosure, the UE may send an A2 measurement report even if the actual LTE measurement is above the A2 event threshold. Furthermore, the UE may send an A2 measurement report with a reported LTE signal quality that is below a threshold associated with triggering a network handover procedure. In some implementations, the reported LTE signal quality may be lower than the actual measured LTE signal quality.

In some implementations, the techniques in this disclosure may be used even when the LTE network has configured measurement gaps for 5G NR measurements. A UE may refrain from performing 5G NR measurements while the UE is connected to the LTE network in an environment that has an attenuated signal quality. For example, the UE may determine a UE that remains in the environment with attenuated signal quality based on the LTE signal quality. The UE may suppress 5G NR measurements until the UE determines that the UE has left the environment based on an improvement in the LTE signal quality. When the UE determines that the LTE signal quality has improved, the UE may resume 5G NR measurements and 5G NR measurement reporting. Alternatively, or additionally, the UE may proactively send an A2 measurement report to cause the LTE network to initiate a network handover procedure.

Particular implementations of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. In a standalone connection, the network may not provide a measurement gap configuration for another network. In some examples of this disclosure, UE may have an LTE connection that does not initially provide measurement gaps for a 5G NR measurement procedure. For example, the LTE connection established when the UE enters the elevator may not provide a measurement configuration to scan for 5G NR base stations. Thus, absent the techniques in this disclosure, it is possible that a UE may not reestablish a 5G NR connection after exiting the elevator. Using the techniques of this disclosure, a UE may monitor signal quality of the LTE connection to determine when the UE has exited the elevator. The UE can prompt the network to initiate a network handover procedure that may otherwise not occur promptly or at all. Thus, the techniques in this disclosure enable a UE to reestablish a 5G NR connection more quickly after existing an environment that temporarily causes the UE to lose a previous 5G NR connection. Furthermore, in implementations in which the UE suppresses 5G NR measurements while the UE is in an environment with an attenuated LTE signal quality, the UE may save power and prevent LTE data service interruptions that would otherwise occur due to the 5G NR measurements.

Figure 1 is a block diagram conceptually illustrating an example of a wireless network 100. The wireless network 100 may be an LTE network or some other wireless network, such as a 5G or NR network. Wireless network 100 may include a number of BSs 110 (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A BS is an entity that communicates with user equipment (UEs) and also may be referred to as a base station, a NR BS, a Node B, a gNB, a 5G node B (NB) , an access point, a transmit receive point (TRP) , or the like. Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to a coverage area of a BS, a BS subsystem serving this coverage area, or a combination thereof, depending on the context in which the term is used.

A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, another type of cell, or a combination thereof. A macro cell may cover a relatively large geographic area (for example, several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (for example, a home) and may allow restricted access by UEs having association with the femto cell (for example, UEs in a closed subscriber group (CSG) ) . A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In the example shown in Figure 1, a BS 110a may be a macro BS for a macro cell 102a, a BS 110b may be a pico BS for a pico cell 102b, and a BS 110c may be a femto BS for a femto cell 102c. A BS may support one or multiple (for example, three) cells. The terms “eNB” , “base station” , “NR BS” , “gNB” , “TRP” , “AP” , “node B” , “5G NB” , and “cell” may be used interchangeably herein.

In some examples, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a mobile BS. In some examples, the BSs may be interconnected to one another as well as to one or more other BSs or network nodes (not shown) in the wireless network 100 through various types of backhaul interfaces, such as a direct physical connection, a virtual network, or a combination thereof using any suitable transport network.

Wireless network 100 also may include relay stations. A relay station is an entity that can receive a transmission of data from an upstream station (for example, a BS or a UE) and send a transmission of the data to a downstream station (for example, a UE or a BS) . A relay station also may be a UE that can relay transmissions for other UEs. In the example shown in Figure 1, a relay station 110d may communicate with macro BS 110a and a UE 120d in order to facilitate communication between BS 110a and UE 120d. A relay station also may be referred to as a relay BS, a relay base station, or a relay, among other examples.

Wireless network 100 may be a heterogeneous network that includes BSs of different types, for example, macro BSs, pico BSs, femto BSs, relay BSs, among other examples. These different types of BSs may have different transmit power levels, different coverage areas, and different impacts on interference in wireless network 100. For example, macro BSs may have a high transmit power level (for example, 5 to 40 Watts) whereas pico BSs, femto BSs, and relay BSs may have lower transmit power levels (for example, 0.1 to 2 Watts) .

A network controller 130 may couple to a set of BSs and may provide coordination and control for these BSs. Network controller 130 may communicate with the BSs via a backhaul. The BSs also may communicate with one another, for example, directly or indirectly via a wireless or wireline backhaul.

UEs 120 (for example, 120a, 120b, 120c) may be dispersed throughout wireless network 100, and each UE may be stationary or mobile. A UE also may be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, or a station, among other examples. A UE may be a cellular phone (for example, a smart phone) , a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or equipment, biometric sensors/devices, wearable devices (smart watches, smart clothing, smart glasses, smart wrist bands, smart jewelry (for example, smart ring, smart bracelet) ) , an entertainment device (for example, a music or video device, or a satellite radio) , a vehicular component or sensor, smart meters/sensors, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium.

Some UEs may be considered machine-type communication (MTC) or evolved or enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, among other examples, that may communicate with a base station, another device (for example, remote device) , or some other entity. A wireless node may provide, for example, connectivity for or to a network (for example, a wide area network such as Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered Internet-of-Things (IoT) devices or may be implemented as NB-IoT (narrowband internet of things) devices. Some UEs may be considered a Customer Premises Equipment (CPE) . UE 120 may be included inside a housing that houses components of UE 120, such as processor components, memory components, similar components, or a combination thereof.

In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular RAT and may operate on one or more frequencies. A RAT also may be referred to as a radio technology, an air interface, among other examples. A frequency also may be referred to as a carrier, a frequency channel, among other examples. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

In some examples, access to the air interface may be scheduled, where a scheduling entity (for example, a base station) allocates resources for communication among some or all devices and equipment within the scheduling entity’s service area or cell. Within the present disclosure, as discussed further below, the scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communication, subordinate entities utilize resources allocated by the scheduling entity.

Base stations are not the only entities that may function as a scheduling entity. That is, in some examples, a UE may function as a scheduling entity, scheduling resources for one or more subordinate entities (for example, one or more other UEs) . In this example, the UE is functioning as a scheduling entity, and other UEs utilize resources scheduled by the UE for wireless communication. A UE may function as a scheduling entity in a peer-to-peer (P2P) network, in a mesh network, or another type of network. In a mesh network example, UEs may optionally communicate directly with one another in addition to communicating with the scheduling entity.

Thus, in a wireless communication network with a scheduled access to time–frequency resources and having a cellular configuration, a P2P configuration, and a mesh configuration, a scheduling entity and one or more subordinate entities may communicate utilizing the scheduled resources.

In some aspects, two or more UEs 120 (for example, shown as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (for example, without using a base station 110 as an intermediary to communicate with one another) . For example, the UEs 120 may communicate using peer-to-peer (P2P) communications, device-to-device (D2D) communications, a vehicle-to-everything (V2X) protocol (which may include a vehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure (V2I) protocol, or similar protocol) , a mesh network, or similar networks, or combinations thereof. In this case, the UE 120 may perform scheduling operations, resource selection operations, as well as other operations described elsewhere herein as being performed by the base station 110.

Figure 2 is a block diagram conceptually illustrating an example 200 of a base station 110 in communication with a UE 120. In some aspects, the base station 110 and the UE 120 may respectively be one of the base stations and one of the UEs in wireless network 100 of Figure 1. Base station 110 may be equipped with T antennas 234a through 234t, and UE 120 may be equipped with R antennas 252a through 252r, where in general T ≥ 1 and R ≥ 1.

At base station 110, a transmit processor 220 may receive data from a data source 212 for one or more UEs, select one or more modulation and coding schemes (MCS) for each UE based at least in part on channel quality indicators (CQIs) received from the UE, process (for example, encode and modulate) the data for each UE based at least in part on the MCS (s) selected for the UE, and provide data symbols for all UEs. The transmit processor 220 also may process system information (for example, for semi-static resource partitioning information (SRPI) or the like) and control information (for example, CQI requests, grants, upper layer signaling, among other examples. ) and provide overhead symbols and control symbols. The transmit processor 220 also may generate reference symbols for reference signals (for example, the cell-specific reference signal (CRS) ) and synchronization signals (for example, the primary synchronization signal (PSS) and secondary synchronization signal (SSS) ) . A transmit (TX) multiple- input multiple-output (MIMO) processor 230 may perform spatial processing (for example, precoding) on the data symbols, the control symbols, the overhead symbols, or the reference symbols, if applicable, and may provide T output symbol streams to T modulators (MODs) 232a through 232t. Each modulator 232 may process a respective output symbol stream (for example, for OFDM) to obtain an output sample stream. Each modulator 232 may further process (for example, convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. T downlink signals from modulators 232a through 232t may be transmitted via T antennas 234a through 234t, respectively. According to various aspects described in more detail below, the synchronization signals can be generated with location encoding to convey additional information.

At UE 120, antennas 252a through 252r may receive the downlink signals from base station 110 or other base stations and may provide received signals to demodulators (DEMODs) 254a through 254r, respectively. Each demodulator 254 may condition (for example, filter, amplify, downconvert, and digitize) a received signal to obtain input samples. Each demodulator 254 may further process the input samples (for example, for OFDM) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all R demodulators 254a through 254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor 258 may process (for example, demodulate and decode) the detected symbols, provide decoded data for UE 120 to a data sink 260, and provide decoded control information and system information to a controller or processor (controller/processor) 280. A channel processor may determine reference signal received power (RSRP) , received signal strength indicator (RSSI) , reference signal received quality (RSRQ) , channel quality indicator (CQI) , among other examples. In some aspects, one or more components of UE 120 may be included in a housing.

On the uplink, at UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information (for example, for reports including RSRP, RSSI, RSRQ, CQI, among other examples) from controller/processor 280. Transmit processor 264 also may generate reference symbols for one or more reference signals. The symbols from transmit processor 264 may be precoded by a TX MIMO processor 266 if applicable, further processed by modulators 254a through 254r (for example, for DFT-s-OFDM, CP-OFDM, among other examples) , and transmitted to base station 110. At base station 110, the uplink signals from UE 120 and other UEs may be received by antennas 234, processed by demodulators 232, detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by UE 120. Receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to a controller or processor (i.e., controller/processor) 240. The base station 110 may include communication unit 244 and communicate to network controller 130 via communication unit 244. The network controller 130 may include communication unit 294, a controller or processor (i.e., controller/processor) 290, and memory 292.

The controller/processor 240 of base station 110, the controller/processor 280 of UE 120, or any other component (s) of Figure 2 may perform one or more techniques associated with managing measurement gap behavior of the first connection based on an operating attribute of the second connection, as described in more detail elsewhere herein. For example, the controller/processor 280 of UE 120, or any other component (s) (or combinations of components) of Figure 2 may perform or direct operations of, for example, process 800 of Figure 8, process 1000 of Figure 10, or other processes as described herein. The

memories

242 and 282 may store data and program codes for base station 110 and UE 120, respectively. The stored program codes, when executed by the controller/processor 280 or other processors and modules at UE 120, may cause the UE 120 to perform operations described with respect to process 800 of Figure 8, process 1000 of Figure 10, or other processes as described herein. A scheduler 246 may schedule UEs for data transmission on the downlink, the uplink, or a combination thereof.

While blocks in Figure 2 are illustrated as distinct components, the functions described above with respect to the blocks may be implemented in a single hardware, software, or combination component or in various combinations of components. For example, the functions described with respect to the transmit processor 264, the receive processor 258, the TX MIMO processor 266, or another processor may be performed by or under the control of controller/processor 280.

Figure 3 is a block diagram conceptually illustrating an example frame structure 300 in a wireless network. In some aspects, the example frame structure 300 may be for FDD in the wireless network, which may include a 5G NR wireless network or another type of wireless network. The transmission timeline for each of the downlink and uplink may be partitioned into units of radio frames (sometimes referred to as frames) . Each radio frame may have a predetermined duration (for example, 10 milliseconds (ms) ) and may be partitioned into a set of Z (Z ≥ 1) subframes (for example, with indices of 0 through Z-1) . Each subframe may have a predetermined duration (for example, 1ms) and may include a set of slots (for example, 2m slots per subframe are shown in Figure 3, where m is a numerology used for a transmission, such as 0, 1, 2, 3, 4, or the like) . Each slot may include a set of L symbol periods. For example, each slot may include fourteen symbol periods (for example, as shown in Figure 3) , seven symbol periods, or another number of symbol periods. In a case where the subframe includes two slots (for example, when m = 1) , the subframe may include 2L symbol periods, where the 2L symbol periods in each subframe may be assigned indices of 0 through 2L–1. In some aspects, a scheduling unit for the FDD may frame-based, subframe-based, slot-based, symbol-based, or the like.

While some techniques are described herein in connection with frames, subframes, slots, or the like, these techniques may equally apply to other types of wireless communication structures, which may be referred to using terms other than “frame, ” “subframe, ” “slot, ” or the like in 5G NR. In some aspects, a wireless communication structure may refer to a periodic time-bounded communication unit defined by a wireless communication standard or protocol. Additionally, or alternatively, different configurations of wireless communication structures than those shown in Figure 3 may be used.

In certain telecommunications (for example, NR) , a base station may transmit synchronization signals. For example, a base station may transmit a primary synchronization signal (PSS) , a secondary synchronization signal (SSS) , or the like, on the downlink for each cell supported by the base station. The PSS and SSS may be used by UEs for cell search and acquisition. For example, the PSS may be used by UEs to determine symbol timing, and the SSS may be used by UEs to determine a physical cell identifier, associated with the base station, and frame timing. The base station also may transmit a physical broadcast channel (PBCH) . The PBCH may carry some system information, such as system information that supports initial access by UEs.

In some aspects, the base station may transmit the PSS, the SSS, the PBCH, or a combination thereof in accordance with a synchronization communication hierarchy (for example, a synchronization signal (SS) hierarchy) including multiple synchronization communications (for example, SS blocks) .

The base station may transmit system information, such as system information blocks (SIBs) on a physical downlink shared channel (PDSCH) in certain slots. The base station may transmit control information/data on a physical downlink control channel (PDCCH) in particular symbol periods of a slot. The base station may transmit traffic data or other data on the PDSCH in the remaining symbol periods of each slot.

A UE may be located within the coverage of multiple BSs. One of these BSs may be selected to serve the UE. The serving BS may be selected based at least in part on various criteria such as received signal strength, received signal quality, path loss, or the like, or combinations thereof. Received signal quality may be quantified by a signal-to-noise-and-interference ratio (SINR) , or a reference signal received quality (RSRQ) , or some other metric. The UE may operate in a dominant interference scenario in which the UE may observe high interference from one or more interfering BSs.

While aspects of the examples described herein may be associated with NR or 5G technologies, aspects of the present disclosure may be applicable with other wireless communication systems. New radio (NR) may refer to radios configured to operate according to a new air interface (for example, other than Orthogonal Frequency Divisional Multiple Access (OFDMA) -based air interfaces) or fixed transport layer (for example, other than Internet Protocol (IP) ) . In aspects, NR may utilize OFDM with a CP (herein referred to as cyclic prefix OFDM or CP-OFDM) or SC-FDM on the uplink, may utilize CP-OFDM on the downlink and include support for half-duplex operation using TDD. In aspects, NR may, for example, utilize OFDM with a CP (herein referred to as CP-OFDM) or discrete Fourier transform spread orthogonal frequency-division multiplexing (DFT-s-OFDM) on the uplink, may utilize CP-OFDM on the downlink and include support for half-duplex operation using TDD. NR may include Enhanced Mobile Broadband (eMBB) service targeting wide bandwidth (for example, 80 megahertz (MHz) and beyond) , millimeter wave (mmW) targeting high carrier frequency (for example, 60 gigahertz (GHz) ) , massive MTC (mMTC) targeting non-backward compatible MTC techniques, or mission critical targeting ultra-reliable low latency communications (URLLC) service.

In some aspects, a single component carrier bandwidth of 100 MHZ may be supported. NR resource blocks may span 12 sub-carriers with a sub-carrier bandwidth of 60 or 120 kilohertz (kHz) over a 0.1 millisecond (ms) duration. Each radio frame may include 40 slots and may have a length of 10 ms. Consequently, each slot may have a length of 0.25 ms. Each slot may indicate a link direction (for example, DL or UL) for data transmission and the link direction for each slot may be dynamically switched. Each slot may include DL/UL data as well as DL/UL control data.

Beamforming may be supported and beam direction may be dynamically configured. MIMO transmissions with precoding also may be supported. MIMO configurations in the DL may support up to 8 transmit antennas with multi-layer DL transmissions up to 8 streams and up to 2 streams per UE. Multi-layer transmissions with up to 2 streams per UE may be supported. Aggregation of multiple cells may be supported with up to 8 serving cells. Alternatively, NR may support a different air interface, other than an OFDM-based interface. NR networks may include entities such central units or distributed units.

Figure 4 shows a block diagram conceptually illustrating an example of a UE that can establish an LTE connection or a 5G NR connection. The block diagram 400 includes a UE 120 that includes a radio 422, a wireless communication module (referred to as interface 424) , and a connection controller 426. In some implementations, a single chip or component of the UE 120 may provide the interface 424 and the connection controller 426 and may communicate via the radio 422. The radio 422 may be capable of establishing a 5G NR connection 452 with a 5G NR base station (gNB) 450. The radio 422 may be capable of establishing an LTE connection 412 with an LTE base station (eNB) 410.

The connection controller 426 may determine which connection to establish via the interface 424 and the radio 422. For example, the connection controller 426 may have a priority or preference configuration that favors one connection type over the other. For some examples in this disclosure, the connection controller 426 may prefer a 5G NR connection 452 over an LTE connection 412. However, when the signal quality of the 5G NR connection 452 falls below a threshold level, the connection controller 426 may direct the interface 424 and the radio 422 to switch to an LTE connection 412.

In the example of Figure 4, the LTE base station 410 (eNB) may provide a measurement gap configuration to the UE 120 to use for the LTE connection 412. For example, the measurement gap configuration may define measurement gap time periods for the UE 120 to periodically measure signals 416 from another base station 414. In some implementations, the LTE base station 410 also may configure a measurement reporting event (A2 event) that instructs the UE to send a measurement report (A2 report) based on configured thresholds. For example, the A2 event configuration may indicate a threshold for RSRQ or RSRP. According to the A2 event configuration, the UE may be expected to send an A2 report if the UE determines that the current RSRQ or RSRP of the first connection is below the A2 event threshold.

When the UE 120 enters an elevator or other environment that causes the UE 120 to disconnect or lose the 5G NR connection 452, the UE 120 may establish the LTE connection 412 to the LTE base station 410. However, as described herein, the LTE base station 410 may not initially configure a measurement configuration for the UE 120 to measure signals from the 5G NR base station 450. For example, the LTE base station 410 may only provide a measurement configuration for other LTE base stations. Thus, when the UE 120 exits the elevator or other environment, the UE 120 may remain connected to the LTE network rather than reestablish a 5G NR connection 452 to a 5G NR base station 450.

In accordance with this disclosure, the connection controller 426 may monitor signal quality of the LTE connection 412 to detect that the UE 120 has left the elevator or other environment. For example, an increase in LTE signal quality of the LTE connection 412 may imply that the UE 120 has left the elevator or other environment. The connection controller 426 may prompt a network handover or cell reselection by causing the interface 424 to send a fake A2 measurement report to the LTE base station 410. The fake A2 measurement report may include a false reported LTE measurement value (lower than the actual measured LTE signal quality) to make the LTE base station 410 initiate a network handover or cell reselection procedure. For example, if the LTE base station 410 had not previously configured 5G NR measurement gaps, the LTE base station 410 may configure a measurement configuration to enable the UE 120 to measure and report 5G NR signal qualities. The A2 measurement report or subsequent 5G NR measurement report may prompt the wireless network to perform a handover from the LTE base station 410 to the 5G NR base station 450.

Figure 5 shows a block diagram 500 conceptually illustrating an example of a UE that changes connections as it moves in and out of an environment that causes a decrease in signal quality. A UE 120 (shown at UE 120 (1) in a first location) may initially have a 5G NR connection 552 with a 5G NR base station 550. When the UE 120 moves to another location (shown at UE 120 (2) in a second location) , the UE may enter an environment 580 (such as an elevator, among other examples) where the signal quality of the 5G NR connection 553 drops below a threshold. The UE 120 (2) may lose the 5G NR connection 443. It should be understood that while the term “lose” a connection is used in this disclosure, it is also possible in some situations that the UE may disconnect, handover, or perform another process that causes the 5G NR connection to become disrupted or unavailable. The UE 120 (2) may establish an LTE connection 512 to an LTE base station 510. While the LTE connection 512 is able to connect and may have a better signal quality than the lost 5G NR connection 553, the LTE connection 512 may have a reduced signal quality while the UE 120 (2) is in the environment 580. In some implementations, the UE 120 (2) may suppress 5G NR measurements while the UE 120 (2) is in the environment 580. The UE 120 (2) may determine that the it has left the environment based on an increase in the LTE signal quality of the LTE connection 512.

Once the UE 120 (shown at UE 120 (3) in a third location) , exits the environment 580, the LTE signal quality of the LTE connection (shown at LTE connection 513) may increase. The UE 120 (3) may determine that the LTE signal quality has increased above a threshold amount or faster than a threshold rate and determine that the UE 120 (3) has exited the environment 580. The UE 120 (3) may send a message (such as an A2 measurement report) to the LTE base station 510 to prompt the LTE base station 510 to initiate a network handover or cell reselection procedure. Alternatively, or additionally, the UE 120 (3) may resume 5G NR measurements and send a 5G NR measurement report to prompt the LTE base station 510 to initiate the network handover or cell reselection procedure. Following the network handover procedure, the UE 120 (3) may establish a 5G NR connection 554 with a 5G NR base station 551. The 5G NR base station 551 may be the same base station as the 5G NR base station 550 that was connected before the UE entered the environment 580 or may be a different 5G NR base station that is available after the UE 120 (3) exits the environment 580.

Figure 6 shows a timing diagram 600 conceptually illustrating example signal quality and connections over time. Initially, a 5G NR signal quality of a 5G NR connection 610 may be at a first level. When the UE enters an elevator (shown at arrow 612) , the 5G NR signal quality may drop causing the UE to lose the 5G NR connection 610. The UE may establish an LTE connection 620. When the UE exits the elevator (shown at arrow 622) , the LTE signal quality may improve. For example, the LTE signal quality of the LTE connection 620 may increase above a threshold amount 630 or faster than a threshold rate. The UE may determine that this increase in LTE signal quality is a result of the UE existing the elevator. The UE may prompt a reconnection to the 5G NR connection 640. For example, the UE may send a measurement report or other message to the LTE base station to force the LTE network to initiate a network handover procedure.

In some implementations, the UE may observe patterns in the signal quality such as those described in the timing diagram 600. For example, the UE may monitor the LTE signal quality during a time period (such as 5 or 10 minutes) after losing the 5G NR connection 610 and establishing the LTE connection 620. If the LTE signal quality increases rapidly during that time period, the UE may infer that the UE was in an elevator during that time period. Other patterns based on signal quality may be possible for other types of environments or venues commonly associated with temporary interference with 5G NR connections.

Figure 7 shows a timing diagram 700 conceptually illustrating an example of changes in average signal quality that trigger a network handover. A UE may determine an average RSRP (RSRP _N) each of a series of time periods (T _N) . By comparing changes in the average RSRP, the UE may determine that the LTE signal quality has increased above a threshold amount or faster than a threshold rate. For example, the UE may determine a first average RSRP (RSRP ₁) for a first time period T ₁ and a second average RSRP (RSRP ₂) . The time period may be a configurable duration. In some implementations, the time period may be 5 seconds.

The UE may determine a difference between consecutive average RSRP values. If the difference between the consecutive average RSRP is greater than a change threshold (RSRP _DELTA) , the UE may determine that the LTE signal quality has increased above a threshold amount or rate and may prompt a network handover. The change threshold may be a configurable value. In some implementations, the change threshold may be between 10 and 20 dB, such as 15 dB. Figure 7 also provides a formula 710 for determining when the UE will prompt the network handover:

RSRP _N-RSRP _N-1＞RSRP _DELTA

Figure 8 shows a flowchart illustrating an example process for prompting wireless service reconnection based on signal change condition according to some implementations. The operations of process 800 may be implemented by a UE or its components as described herein. For example, the process 800 may be performed by an apparatus such as UE 120 described above with reference to Figure 4 or a wireless communication device such as the wireless communication device 1100 described with reference to Figure 11. At block 810, the apparatus may determine that the UE has lost a first connection to a 5G NR network. At block 820, the apparatus may establish a second connection to an LTE network in response to losing the first connection. At block 830, the apparatus may monitor a measured LTE signal quality associated with the second connection. At block 840, the apparatus may, in response to detecting an increase in the measured LTE signal quality above a threshold amount, output a measurement report for transmission to the LTE network to cause the LTE network to initiate a network handover procedure so that the UE can establish a new connection to the 5G NR network.

Figure 9 shows a conceptual diagram of an example message 900 to trigger a wireless service reconnection according to some implementations. The message 900 may include a frame header 924 and a payload 910. The frame header 924 may indicate the type of message or other frame control information. The payload 910 may include a variety of elements or fields 932. Figure 9 includes several example elements or fields 960.

In some implementations, the example elements or fields 960 may include a measurement report. For example, the example elements or fields 960 may include a reported LTE signal quality 962. The reported LTE signal quality 962 may include a fake or fictitious value that is intended to prompt the LTE network to initiate a network handover or cell reselection procedure.

In some implementations, the example elements or fields 960 may include an A2 event report 964. The A2 event report 964 may include an indicator that the A2 threshold was triggered and may prompt the LTE network to initiate a network handover or cell reselection procedure.

Other types of elements, fields, or indicators may be conceivable to include in the example message 900 to prompt the LTE network to initiate a network handover or cell reselection procedure. For example, in some implementations, the example elements or fields 960 may include a network handover requested indicator 966 that indicates that the UE is requesting a network handover procedure.

Figure 10 shows a flowchart illustrating an example process 1000 for determining whether to perform a measurement procedure during a measurement gap time period according to some implementations. The operations of process 1000 may be implemented by a UE or its components as described herein. For example, the process 1000 may be performed by an apparatus such as UE 120 described above with reference to Figure 4 or a wireless communication device such as the wireless communication device 1100 described with reference to Figure 11.

At block 1010, the apparatus may establish a 5G NR connection. At some time later, the apparatus may enter an environment that causes the 5G NR signal quality to decrease or diminish below a threshold at which the 5G NR connection may be maintained.

At block 1020, the apparatus may lose the 5G NR connection. At block 1030, the apparatus may establish an LTE connection. The LTE connection may permit the apparatus to maintain connectivity with the wireless communication network in lieu of the 5G NR connection.

At block 1040, the apparatus may determine whether the LTE connection has configured a 5G NR measurement configuration, such as a measurement gap or 5G NR measurement policy. If so, the process 1000 may continue to block 1080, where the apparatus may perform the measurement procedure normally. However, if at block 1040, the apparatus determines that the LTE connection has not configured the 5G NR measurement configuration, the process 1000 may proceed to block 1050.

At block 1050, the apparatus may monitor the LTE signal quality and determine whether a rapid increase in LTE signal quality is detected. An example of a rapid increase may be a 15 dB increase over a 5 second period of time. Alternatively, or additionally, the apparatus may determine whether the LTE signal quality increases above a threshold amount. If the apparatus determines that a rapid increase in LTE signal quality has been detected, the process 1000 proceeds to block 1060. Otherwise, the process 1000 continues to monitor the LTE signal quality at block 1050.

At block 1060, the apparatus may send an A2 event measurement report to the LTE base station to trigger a network handover procedure. For example, the apparatus may output the A2 event measurement report for transmission to the LTE base station by an interface or modem of the apparatus. In some implementations, the A2 event measurement report may include a fake or fictitious value for the reported LTE signal quality to force the LTE base station to initiate the network handover procedure.

At block 1070, the apparatus may receive a 5G NR measurement configuration from the LTE base station as part of the network handover procedure. The process 1000 may proceed to block 1080 at which the apparatus performs the measurement procedure to determine if there is a 5G NR base station suitable for the apparatus to reestablish a 5G NR connection. At block 1090, the apparatus may establish the 5G NR connection.

Figure 11 shows a block diagram of an example wireless communication device 1100. In some implementations, the wireless communication device 1100 can be an example of a device for use in a UE, such as UE 120 described above with reference to Figure 1. The wireless communication device 1100 is capable of transmitting (or outputting for transmission) and receiving wireless communications.

The wireless communication device 1100 can be, or can include, a chip, system on chip (SoC) , chipset, package or device. The term “system-on-chip” (SoC) is used herein to refer to a set of interconnected electronic circuits typically, but not exclusively, including one or more processors, a memory, and a communication interface. The SoC may include a variety of different types of processors and processor cores, such as a general purpose processor, a central processing unit (CPU) , a digital signal processor (DSP) , a graphics processing unit (GPU) , an accelerated processing unit (APU) , a sub-system processor, an auxiliary processor, a single-core processor, and a multicore processor. The SoC may further include other hardware and hardware combinations, such as a field programmable gate array (FPGA) , a configuration and status register (CSR) , an application-specific integrated circuit (ASIC) , other programmable logic device, discrete gate logic, transistor logic, registers, performance monitoring hardware, watchdog hardware, counters, and time references. SoCs may be integrated circuits (ICs) configured such that the components of the IC reside on the same substrate, such as a single piece of semiconductor material (such as, for example, silicon) .

The term “system in a package” (SIP) is used herein to refer to a single module or package that may contain multiple resources, computational units, cores and/or processors on two or more IC chips, substrates, or SoCs. For example, a SIP may include a single substrate on which multiple IC chips or semiconductor dies are stacked in a vertical configuration. Similarly, the SIP may include one or more multi-chip modules (MCMs) on which multiple ICs or semiconductor dies are packaged into a unifying substrate. A SIP also may include multiple independent SoCs coupled together via high speed communication circuitry and packaged in close proximity, such as on a single motherboard or in a single mobile communication device. The proximity of the SoCs facilitates high speed communications and the sharing of memory and resources.

The term “multicore processor” is used herein to refer to a single IC chip or chip package that contains two or more independent processing cores (for example a CPU core, IP core, GPU core, among other examples) configured to read and execute program instructions. An SoC may include multiple multicore processors, and each processor in an SoC may be referred to as a core. The term “multiprocessor” may be used herein to refer to a system or device that includes two or more processing units configured to read and execute program instructions.

The wireless communication device 1100 may include one or more modems 1102. In some implementations, the one or more modems 1102 (collectively “the modem 1102” ) may include a WWAN modem (for example, a 3GPP 4G LTE or 5G compliant modem) . In some implementations, the wireless communication device 1100 also includes one or more radios 1104 (collectively “the radio 1104” ) . In some implementations, the wireless communication device 1100 further includes one or more processors, processing blocks or processing elements 1106 (collectively “the processor 1106” ) and one or more memory blocks or elements 1108 (collectively “the memory 1108” ) .

The modem 1102 can include an intelligent hardware block or device such as, for example, an application-specific integrated circuit (ASIC) among other possibilities. The modem 1102 is generally configured to implement a PHY layer. For example, the modem 1102 is configured to modulate packets and to output the modulated packets to the radio 1104 for transmission over the wireless medium. The modem 1102 is similarly configured to obtain modulated packets received by the radio 1104 and to demodulate the packets to provide demodulated packets. In addition to a modulator and a demodulator, the modem 1102 may further include digital signal processing (DSP) circuitry, automatic gain control (AGC) , a coder, a decoder, a multiplexer and a demultiplexer. For example, while in a transmission mode, data obtained from the processor 1106 is provided to a coder, which encodes the data to provide encoded bits. The encoded bits are then mapped to points in a modulation constellation (using a selected MCS) to provide modulated symbols. The modulated symbols may then be mapped to a number NSS of spatial streams or a number NSTS of space-time streams. The modulated symbols in the respective spatial or space-time streams may then be multiplexed, transformed via an inverse fast Fourier transform (IFFT) block, and subsequently provided to the DSP circuitry for Tx windowing and filtering. The digital signals may then be provided to a digital-to-analog converter (DAC) . The resultant analog signals may then be provided to a frequency upconverter, and ultimately, the radio 1104. In implementations involving beamforming, the modulated symbols in the respective spatial streams are precoded via a steering matrix prior to their provision to the IFFT block.

While in a reception mode, digital signals received from the radio 1104 are provided to the DSP circuitry, which is configured to acquire a received signal, for example, by detecting the presence of the signal and estimating the initial timing and frequency offsets. The DSP circuitry is further configured to digitally condition the digital signals, for example, using channel (narrowband) filtering, analog impairment conditioning (such as correcting for I/Q imbalance) , and applying digital gain to ultimately obtain a narrowband signal. The output of the DSP circuitry may then be fed to the AGC, which is configured to use information extracted from the digital signals, for example, in one or more received training fields, to determine an appropriate gain. The output of the DSP circuitry also is coupled with the demodulator, which is configured to extract modulated symbols from the signal and, for example, compute the logarithm likelihood ratios (LLRs) for each bit position of each subcarrier in each spatial stream. The demodulator is coupled with the decoder, which may be configured to process the LLRs to provide decoded bits. The decoded bits from all of the spatial streams are then fed to the demultiplexer for demultiplexing. The demultiplexed bits may then be descrambled and provided to the MAC layer (the processor 1106) for processing, evaluation, or interpretation.

The radio 1104 generally includes at least one radio frequency (RF) transmitter (or “transmitter chain” ) and at least one RF receiver (or “receiver chain” ) , which may be combined into one or more transceivers. For example, the RF transmitters and receivers may include various DSP circuitry including at least one power amplifier (PA) and at least one low-noise amplifier (LNA) , respectively. The RF transmitters and receivers may, in turn, be coupled to one or more antennas. For example, in some implementations, the wireless communication device 1100 can include, or be coupled with, multiple transmit antennas (each with a corresponding transmit chain) and multiple receive antennas (each with a corresponding receive chain) . The symbols output from the modem 1102 are provided to the radio 1104, which then transmits the symbols via the coupled antennas. Similarly, symbols received via the antennas are obtained by the radio 1104, which then provides the symbols to the modem 1102.

The processor 1106 can include an intelligent hardware block or device such as, for example, a processing core, a processing block, a central processing unit (CPU) , a microprocessor, a microcontroller, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a programmable logic device (PLD) such as a field programmable gate array (FPGA) , discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The processor 1106 processes information received through the radio 1104 and the modem 1102, and processes information to be output through the modem 1102 and the radio 1104 for transmission through the wireless medium. In some implementations, the processor 1106 may generally control the modem 1102 to cause the modem to perform various operations described above.

The memory 1108 can include tangible storage media such as random-access memory (RAM) or read-only memory (ROM) , or combinations thereof. The memory 1108 also can store non-transitory processor-or computer-executable software (SW) code containing instructions that, when executed by the processor 1106, cause the processor to perform various operations described herein for wireless communication, including the generation, transmission, reception and interpretation of MPDUs, frames or packets. For example, various functions of components disclosed herein, or various blocks or steps of a method, operation, process or algorithm disclosed herein, can be implemented as one or more modules of one or more computer programs.

Figures 1–11 and the operations described herein are examples meant to aid in understanding example implementations and should not be used to limit the potential implementations or limit the scope of the claims. Some implementations may perform additional operations, fewer operations, operations in parallel or in a different order, and some operations differently.

The foregoing disclosure provides illustration and description but is not intended to be exhaustive or to limit the aspects to the precise form disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the aspects.

As used herein, the term “component” is intended to be broadly construed as hardware, firmware, or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, or a combination of hardware and software. As used herein, the phrase “based on” is intended to be broadly construed to mean “based at least in part on. ”

Some aspects are described herein in connection with thresholds. As used herein, satisfying a threshold may refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, or the like.

As used herein, a phrase referring to “at least one of” or “one or more of” a list of items refers to any combination of those items, including single members. For example, “at least one of: a, b, or c” is intended to cover the possibilities of: a only, b only, c only, a combination of a and b, a combination of a and c, a combination of b and c, and a combination of a and b and c.

The various illustrative components, logic, logical blocks, modules, circuits, operations and algorithm processes described in connection with the implementations disclosed herein may be implemented as electronic hardware, firmware, software, or combinations of hardware, firmware or software, including the structures disclosed in this specification and the structural equivalents thereof. The interchangeability of hardware, firmware and software has been described generally, in terms of functionality, and illustrated in the various illustrative components, blocks, modules, circuits and processes described above. Whether such functionality is implemented in hardware, firmware or software depends upon the particular application and design constraints imposed on the overall system.

The hardware and data processing apparatus used to implement the various illustrative components, logics, logical blocks, modules and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose single- or multi-chip processor, a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a field programmable gate array (FPGA) or other programmable logic device (PLD) , discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. A processor also may be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some implementations, particular processes, operations and methods may be performed by circuitry that is specific to a given function.

As described above, in some aspects implementations of the subject matter described in this specification can be implemented as software. For example, various functions of components disclosed herein, or various blocks or steps of a method, operation, process or algorithm disclosed herein can be implemented as one or more modules of one or more computer programs. Such computer programs can include non-transitory processor-or computer-executable instructions encoded on one or more tangible processor-or computer-readable storage media for execution by, or to control the operation of, data processing apparatus including the components of the devices described herein. By way of example, and not limitation, such storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to store program code in the form of instructions or data structures. Combinations of the above should also be included within the scope of storage media.

As used herein, the terms “user equipment” , “wireless communication device” , “mobile communication device” , “communication device” , and/or “mobile device” refer to any one or all of cellular telephones, smartphones, portable computing devices, personal or mobile multi-media players, laptop computers, tablet computers, smartbooks, Internet-of-Things (IoT) devices, palm-top computers, wireless electronic mail receivers, multimedia Internet enabled cellular telephones, wireless gaming controllers, display sub-systems, driver assistance systems, vehicle controllers, vehicle system controllers, vehicle communication system, infotainment systems, vehicle telematics systems or subsystems, vehicle display systems or subsystems, vehicle data controllers or routers, and similar electronic devices which include a programmable processor and memory and circuitry configured to perform operations as described herein.

As used herein, the terms “SIM, ” “SIM card, ” and “subscriber identification module” are used interchangeably to refer to a memory that may be an integrated circuit or embedded into a removable card, and that stores an International Mobile Subscriber Identity (IMSI) , related key, and/or other information used to identify and/or authenticate a mobile communication device on a network and enable a communication service with the network. Because the information stored in a SIM enables the mobile communication device to establish a communication link for a particular communication service with a particular network, the term “subscription” is used herein as a shorthand reference to refer to the communication service associated with and enabled by the information stored in a particular SIM as the SIM and the communication network, as well as the services and subscriptions supported by that network, correlate to one another. A SIM used in various examples may contain user account information, an international mobile subscriber identity (IMSI) , a set of SIM application toolkit (SAT) commands, and storage space for phone book contacts. A SIM card may further store home identifiers (such as, a System Identification Number (SID) /Network Identification Number (NID) pair, a Home Public Land Mobile Number (HPLMN) code, among other examples) to indicate the SIM card network operator provider. An Integrated Circuit Card Identity (ICCID) SIM serial number may be printed on the SIM card for identification. However, a SIM may be implemented within a portion of memory of the mobile communication device, and thus need not be a separate or removable circuit, chip or card.

Various modifications to the implementations described in this disclosure may be readily apparent to persons having ordinary skill in the art, and the generic principles defined herein may be applied to other implementations without departing from the spirit or scope of this disclosure. Thus, the claims are not intended to be limited to the implementations shown herein but are to be accorded the widest scope consistent with this disclosure, the principles and the novel features disclosed herein.

Additionally, various features that are described in this specification in the context of separate implementations also can be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation also can be implemented in multiple implementations separately or in any suitable subcombination. As such, although features may be described above as acting in particular combinations, and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Further, the drawings may schematically depict one or more example processes in the form of a flowchart or flow diagram. However, other operations that are not depicted can be incorporated in the example processes that are schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the illustrated operations. In some circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. Additionally, other implementations are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results.

Claims

A method for wireless communication performed by an apparatus of a user equipment (UE) , comprising:

determining that the UE has lost a first connection to a 5G New Radio (NR) network;

establishing a second connection to a Long-Term Evolution (LTE) network in response to losing the first connection;

monitoring a measured LTE signal quality associated with the second connection; and

in response to detecting an increase in the measured LTE signal quality above a threshold amount, outputting a measurement report for transmission to the LTE network to cause the LTE network to initiate a network handover procedure so that the UE can establish a new connection to the 5G NR network.
The method of claim 1, further comprising:

determining that the UE has lost the first connection to the 5G NR network as a result of the UE entering an environment, wherein the increase in the measured LTE signal quality being above the threshold amount is indicative that the UE has left the environment.
The method of claim 2, wherein the environment is an elevator, underground tunnel, building, parking structure, sports venue, or vehicle.
The method of claim 1, wherein the measured LTE signal quality is a metric based on at least one member selected from a group consisting of a reference signal received power (RSRP) , a reference signal received quality (RSRQ) , and a received signal strength indicator (RSSI) .
The method of claim 1, wherein detecting that the increase in the measured LTE signal quality is above the threshold amount includes:

determining a rate of change in the measured LTE signal quality over time; and

detecting that the increase in the measured LTE signal quality is above the threshold amount when the rate of change is above the threshold amount.
The method of claim 1, wherein detecting that the increase in the measured LTE signal quality is above the threshold amount includes:

determining a first average LTE signal quality based on the measured LTE signal quality over a first time period;

determining a second average LTE signal quality based on the measured LTE signal quality over a second time period following the first time period; and

determining that a difference between the second average LTE signal quality and the first average LTE signal quality is above the threshold amount.
The method of claim 6, wherein the first time period is 5 seconds and the second time period is 5 seconds immediately following the first time period, and wherein the threshold amount is a change of 15 decibels (dB) between the first average LTE signal quality and the second average LTE signal quality.
The method of claim 1, wherein the measurement report includes a reported LTE signal quality that is lower than the actual measured LTE signal quality.
The method of claim 8, wherein the reported LTE signal quality is below a threshold configuration value associated with triggering the network handover procedure.
The method of claim 1, further comprising:

determining that a measurement reporting event (A2 event) and an A2 event threshold are configured for the second connection, the A2 event threshold associated with triggering the network handover procedure,

wherein sending the measurement report to the LTE network includes sending an A2 event report with a reported LTE signal quality that is lower than the A2 event threshold regardless of whether the measured LTE signal quality is lower than the A2 event threshold.
The method of claim 1, further comprising:

temporarily suppressing a 5G NR measurement procedure in response to establishing the second connection to the LTE network; and

resuming the 5G NR measurement procedure after detecting the increase in the measured LTE signal quality above the threshold amount.
A user equipment (UE) for wireless communication, comprising:

one or more processors configured to:

determine that the UE has lost a first connection to a 5G New Radio (NR) network;

establish a second connection to a Long-Term Evolution (LTE) network in response to losing the first connection; and

monitor a measured LTE signal quality associated with the second connection; and

in response to detecting an increase in the measured LTE signal quality above a threshold amount, cause an interface to output a measurement report for transmission to the LTE network to cause the LTE network to initiate a network handover procedure so that the UE can establish a new connection to the 5G NR network.
The UE of claim 12, wherein the one or more processors are further configured to:

determine that the UE has lost the first connection to the 5G NR network as a result of the UE entering an environment, wherein the increase in the measured LTE signal quality being above the threshold amount is indicative that the UE has left the environment.
The UE of claim 13, wherein the environment is an elevator, underground tunnel, building, parking structure, sports venue, or vehicle.
The UE of claim 12, wherein the measured LTE signal quality is a metric based on at least one member selected from a group consisting of a reference signal received power (RSRP) , a reference signal received quality (RSRQ) , and a received signal strength indicator (RSSI) .
The UE of claim 12, wherein the one or more processors are further configured to:

determine a rate of change in the measured LTE signal quality over time; and

detect that the increase in the measured LTE signal quality is above the threshold amount when the rate of change is above the threshold amount.
The UE of claim 12, wherein the one or more processors are further configured to:

determine a first average LTE signal quality based on the measured LTE signal quality over a first time period;

determine a second average LTE signal quality based on the measured LTE signal quality over a second time period following the first time period; and

determine that a difference between the second average LTE signal quality and the first average LTE signal quality is above the threshold amount.
The UE of claim 17, wherein the first time period is 5 seconds and the second time period is 5 seconds immediately following the first time period, and wherein the threshold amount is a change of 15 decibels (dB) between the first average LTE signal quality and the second average LTE signal quality.
The UE of claim 12, wherein the measurement report includes a reported LTE signal quality that is lower than the actual measured LTE signal quality.
The UE of claim 19, wherein the reported LTE signal quality is below a threshold configuration value associated with triggering the network handover procedure.
The UE of claim 12, wherein the one or more processors are further configured to:

determine that a measurement reporting event (A2 event) and an A2 event threshold are configured for the second connection, the A2 event threshold associated with triggering the network handover procedure,

wherein the measurement report is an A2 event report with a reported LTE signal quality that is lower than the A2 event threshold regardless of whether the measured LTE signal quality is lower than the A2 event threshold.
The UE of claim 12, wherein the one or more processors are further configured to:

temporarily suppress a 5G NR measurement procedure in response to establishing the second connection to the LTE network; and

resume the 5G NR measurement procedure after detecting the increase in the measured LTE signal quality above the threshold amount.
A computer-readable medium having stored therein instructions which, when executed by a processor of a user equipment (UE) , causes the processor to:

determine that the UE has lost a first connection to a 5G New Radio (NR) network;

establish a second connection to a Long-Term Evolution (LTE) network in response to losing the first connection; and

monitor a measured LTE signal quality associated with the second connection; and

in response to detecting an increase in the measured LTE signal quality above a threshold amount, output a measurement report for transmission to the LTE network to cause the LTE network to initiate a network handover procedure so that the UE can establish a new connection to the 5G NR network.
The computer-readable medium of claim 23, wherein the instructions, when executed by the processor, cause the processor to:

determine that the UE has lost the first connection to the 5G NR network as a result of the UE entering an environment, wherein the increase in the measured LTE signal quality being above the threshold amount is indicative that the UE has left the environment.
The computer-readable medium of claim 23, wherein the instructions, when executed by the processor, cause the processor to:

determine a rate of change in the measured LTE signal quality over time; and

detect that the increase in the measured LTE signal quality is above the threshold amount when the rate of change is above the threshold amount.
The computer-readable medium of claim 23, wherein the instructions, when executed by the processor, cause the processor to:

determine a first average LTE signal quality based on the measured LTE signal quality over a first time period;

determine a second average LTE signal quality based on the measured LTE signal quality over a second time period following the first time period; and

determine that a difference between the second average LTE signal quality and the first average LTE signal quality is above the threshold amount.
A wireless communication device comprising:

at least one modem;

at least one processor communicatively coupled with the at least one modem; and

at least one memory communicatively coupled with the at least one processor and storing processor-readable code that, when executed by the at least one processor in conjunction with the at least one modem, is configured to:

determine that the UE has lost a first connection to a 5G New Radio (NR) network;

establish a second connection to a Long-Term Evolution (LTE) network in response to losing the first connection; and

monitor a measured LTE signal quality associated with the second connection; and

in response to detecting an increase in the measured LTE signal quality above a threshold amount, cause the at least one modem to output a measurement report for transmission to the LTE network to cause the LTE network to initiate a network handover procedure so that the UE can establish a new connection to the 5G NR network.
The wireless communication device of claim 27, wherein the processor-readable code, when executed by the at least one processor, cause the processor to:

determine that the UE has lost the first connection to the 5G NR network as a result of the UE entering an environment, wherein the increase in the measured LTE signal quality being above the threshold amount is indicative that the UE has left the environment.
The wireless communication device of claim 27, wherein the processor-readable code, when executed by the at least one processor, cause the processor to:

determine that a measurement reporting event (A2 event) and an A2 event threshold are configured for the second connection, the A2 event threshold associated with triggering the network handover procedure,

wherein the measurement report is an A2 event report with a reported LTE signal quality that is lower than the A2 event threshold regardless of whether the measured LTE signal quality is lower than the A2 event threshold.
An apparatus comprising:

the wireless communication device comprising:

at least one modem;

at least one processor communicatively coupled with the at least one modem; and

at least one memory communicatively coupled with the at least one processor and storing processor-readable code that, when executed by the at least one processor in conjunction with the at least one modem, is configured to:

determine that the UE has lost a first connection to a 5G New Radio (NR) network;

establish a second connection to a Long-Term Evolution (LTE) network in response to losing the first connection; and

monitor a measured LTE signal quality associated with the second connection; and

in response to detecting an increase in the measured LTE signal quality above a threshold amount, cause the at least one modem to output a measurement report for transmission to the LTE network to cause the LTE network to initiate a network handover procedure so that the UE can establish a new connection to the 5G NR network;

at least one transceiver coupled to the at least one modem;

a plurality of antennas coupled to the at least one transceiver to wirelessly transmit signals output from the at least one transceiver; and

a housing that encompasses the at least one modem, the at least one processor, the at least one memory, the at least one transceiver and at least a portion of the plurality of antennas.
A system, comprising:

means for determining that the UE has lost a first connection to a 5G New Radio (NR) network;

means for establishing a second connection to a Long-Term Evolution (LTE) network in response to losing the first connection;

means for monitoring a measured LTE signal quality associated with the second connection; and

in response to detecting an increase in the measured LTE signal quality above a threshold amount, means for causing an interface to output a measurement report for transmission to the LTE network to cause the LTE network to initiate a network handover procedure so that the UE can establish a new connection to the 5G NR network.