A method, device and computer readable medium for communication

Abstract

An apparatus is provided, the apparatus comprising components for operating using a first measurement configuration, determining that a first trigger condition associated with at least a radio link failure indicator is met, and in response to the determination, operating using a second measurement configuration until a second trigger condition is met, wherein operating using the second measurement configuration comprises at least one of the following operations: performing measurements with reduced periodicity, an increased number of samples and / or an increased number of reports, increasing the number of neighbor cells measured, and reducing the time used to trigger a switching cycle relative to the first measurement configuration.

Description

Technical Field

[0001] The present application relates to methods, apparatus, systems and computer programs and particularly, but not exclusively, to error prediction and measurement recovery. Background Art

[0002] A communication system can be viewed as a facility for enabling communication sessions between two or more entities (such as user terminals, base stations and / or other nodes) by providing a carrier between the various entities involved in the communication path. A communication system can be provided, for example, by a communication network and one or more compatible communication devices (also referred to as stations or user equipment) and / or application servers. A communication session can include, for example, communications for carrying data for communication, such as voice, video, email, text messages, multimedia, content data, time-sensitive network (TSN) streams and / or data in industrial applications, such as critical system messages between actuators and controllers, critical sensor data (such as measurements, video feeds, etc.) transmitted to the control system, and the like. Non-limiting examples of the services provided include two-way or multi-way calls, data communications or multimedia services, and access to data network systems such as the Internet.

[0003] In a wireless communication system, at least a part of a communication session (e.g., between at least two stations or between at least one station and at least one application server (e.g., for video)) takes place over a wireless link. Examples of wireless systems include public land mobile networks (PLMNs) operating based on 3GPP radio standards, such as E-UTRA, New Radio, satellite-based communication systems, and different wireless local area networks, such as wireless local area networks (WLANs). Wireless systems can generally be divided into cells, and therefore they are often referred to as cellular systems.

[0004] A user can access the communication system through an appropriate communication device or terminal. The user's communication device may be referred to as a user equipment (UE) or user device. The communication device is equipped with appropriate signal receiving and sending devices for implementing communications, such as implementing access to a communication network or communicating directly with other users. The communication device can access one or more carriers provided by the network, such as a base station of a cell, and send and / or receive communications on one or more carriers.

[0005] Communication systems and associated equipment typically operate according to a given standard or specification that specifies what the various entities associated with the system are allowed to do and how it should be achieved. Communication protocols and / or parameters that will be used for the connection are also typically defined. An example of a communication system is UTRAN (3G radio). Other examples of communication systems are the Long Term Evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) based on the E-UTRAN radio access technology, and the so-called 5G System (5GS) including 5G or Next Generation Core (NGC) and 5G access networks based on the New Radio (NR) radio access technology. 5G including NR is being standardized by the Third Generation Partnership Project (3GPP). Summary of the invention

[0006] In a first aspect, an apparatus is provided, comprising components for operating using a first measurement configuration, determining that a first trigger condition associated with at least a radio link failure indicator is met, and in response to the determination, operating using a second measurement configuration until the second trigger condition is met, wherein operating using the second measurement configuration comprises at least one of performing measurements with reduced periodicity, an increased number of samples and / or an increased number of reports, increasing the number of neighbor cells measured, and reducing a time for triggering a switching cycle relative to the first measurement configuration.

[0007] The first measurement configuration may be a power saving measurement configuration.

[0008] The first measurement configuration and the second measurement configuration may include a radio resource management measurement and reporting configuration.

[0009] The radio link failure indicator may include at least one of the following: a radio link failure counter; a radio link timer; determining that the reference signal received power is lower than a first threshold; determining that the physical downlink control channel or the physical downlink shared channel decoding fails; performing a new cell discovery; and determining the disappearance of a known cell.

[0010] The apparatus may include means for operating using the second measurement configuration after the first counter value is satisfied or after expiration of a timer after the first trigger condition is satisfied.

[0011] The second trigger condition may include at least one of: a reset of a radio link failure timer, a radio link failure, and usage of the first amount of resources.

[0012] The apparatus may include means for performing a synchronization attempt while the apparatus is operating using the second measurement configuration.

[0013] The apparatus may include means for operating using the first measurement configuration or the third measurement configuration after the second trigger condition is met.

[0014] In a second aspect, a method is provided, comprising: operating using a first measurement configuration, determining that a first trigger condition associated with at least a radio link failure indicator is met, and in response to the determination, operating using a second measurement configuration until the second trigger condition is met, wherein operating using the second measurement configuration includes at least one of the following operations: performing measurements with reduced periodicity, an increased number of samples and / or an increased number of reports, increasing the number of neighbor cells measured, and reducing the time used to trigger a switching cycle relative to the first measurement configuration.

[0015] The first measurement configuration may be a power saving measurement configuration.

[0016] The first measurement configuration and the second measurement configuration may include a radio resource management measurement and reporting configuration.

[0017] The radio link failure indicator may include at least one of the following: a radio link failure counter; a radio link timer; determining that the reference signal received power is lower than a first threshold; determining that the physical downlink control channel or the physical downlink shared channel decoding fails; performing a new cell discovery; and determining the disappearance of a known cell.

[0018] The method may comprise operating using the second measurement configuration after the first counter value is satisfied or after expiration of a timer after the first trigger condition is satisfied.

[0019] The second trigger condition may include at least one of: a reset of a radio link failure timer, a radio link failure, and usage of the first amount of resources.

[0020] The method may include performing a synchronization attempt while the apparatus is operating using the second measurement configuration.

[0021] The method may include operating using the first measurement configuration or the third measurement configuration after the second trigger condition is met.

[0022] In a third aspect, an apparatus is provided, comprising at least one processor and at least one memory comprising computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least: operate using a first measurement configuration; determine that a first trigger condition associated with at least a radio link failure indicator is met; and in response to the determination, operate using a second measurement configuration until the second trigger condition is met, wherein operating using the second measurement configuration comprises at least one of the following operations: performing measurements with reduced periodicity, an increased number of samples and / or an increased number of reports, increasing the number of neighbor cells measured, and reducing the time used to trigger a switching cycle relative to the first measurement configuration.

[0023] The first measurement configuration may be a power saving measurement configuration.

[0024] The first measurement configuration and the second measurement configuration may include a radio resource management measurement and reporting configuration.

[0025] The radio link failure indicator may include at least one of the following: a radio link failure counter; a radio link timer; determining that the reference signal received power is lower than a first threshold; determining that the physical downlink control channel or the physical downlink shared channel decoding fails; performing a new cell discovery; and determining the disappearance of a known cell.

[0026] The apparatus may be configured to use the second measurement configuration after the first counter value is satisfied or after expiration of a timer after determining that the first trigger condition is satisfied.

[0027] The second trigger condition may include at least one of: a reset of a radio link failure timer, a radio link failure, and usage of the first amount of resources.

[0028] The apparatus may be configured to perform a synchronization attempt while the apparatus is operating using the second measurement configuration.

[0029] The apparatus may be configured to operate using the first measurement configuration or the third measurement configuration after the second trigger condition is met.

[0030] In a fourth aspect, a computer-readable medium is provided, comprising program instructions for causing an apparatus to perform at least the following operations: operate using a first measurement configuration; determine that a first trigger condition associated with at least a radio link failure indicator is met; and in response to the determination, operate using a second measurement configuration until the second trigger condition is met, wherein operating using the second measurement configuration comprises at least one of the following operations: performing measurements with reduced periodicity, an increased number of samples and / or an increased number of reports, increasing the number of neighbor cells measured, and reducing the time used to trigger a switching cycle relative to the first measurement configuration.

[0031] The first measurement configuration may be a power saving measurement configuration.

[0032] The first measurement configuration and the second measurement configuration may include a radio resource management measurement and reporting configuration.

[0033] The radio link failure indicator may include at least one of the following: a radio link failure counter; a radio link timer; determining that the reference signal received power is lower than a first threshold; determining that the physical downlink control channel or the physical downlink shared channel decoding fails; performing a new cell discovery; and determining the disappearance of a known cell.

[0034] The apparatus may be caused to operate using the second measurement configuration after the first counter value is satisfied or after expiration of a timer after determining that the first trigger condition is satisfied.

[0035] The second trigger condition may include at least one of: a reset of a radio link failure timer, a radio link failure, and usage of the first amount of resources.

[0036] The apparatus may be caused to perform a synchronization attempt while the apparatus is operating using the second measurement configuration.

[0037] The apparatus may be caused to operate using the first measurement configuration or the third measurement configuration after the second trigger condition is met.

[0038] In a fifth aspect, a non-transitory computer readable medium is provided, comprising program instructions for causing an apparatus to at least perform the method according to the fourth aspect.

[0039] In the above statement, many different embodiments have been described. It should be understood that further embodiments can be provided by combining any two or more of the above embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0041] Figure 1 A schematic diagram of an example communication system including a base station and a plurality of communication devices is shown;

[0042] Figure 2 A schematic diagram of an example mobile communication device is shown;

[0043] Figure 3 A schematic diagram of an example control device is shown;

[0044] Figure 4 a graph showing the number of Radio Link Failures (RLFs) as a function of measurement period for UEs moving at different speeds;

[0045] Figure 5 The signaling flow for the RLF process is shown;

[0046] Figure 6 A flow chart showing a method according to an example embodiment is shown;

[0047] Figure 7 A schematic diagram showing transitions between measurement states;

[0048] Figure 8 shows a signaling flow of a RLF procedure according to an example embodiment;

[0049] Fig. 9 A signaling flow of a RLF procedure according to an example embodiment is shown. DETAILED DESCRIPTION

[0050] Before explaining the examples in detail, refer to Figures 1 to 3 Certain general principles of wireless communication systems and mobile communication devices are briefly explained to aid understanding of the technology behind the described examples.

[0051] In such Figure 1 In the wireless communication system 100 shown, wireless access is provided to mobile communication devices or user equipment (UE) 102, 104, 105 via at least one base station (e.g., next generation NB, gNB) or similar wireless transmission and / or reception node or point. The base station can be controlled or assisted by at least one appropriate controller device to enable operation and management of mobile communication devices communicating with the base station. The controller device can be located in a radio access network (e.g., wireless communication system 100) or in a core network (CN) (not shown) and can be implemented as a central device, or its functions can be distributed over several devices. The controller device can be part of the base station and / or provided by a separate entity such as a radio network controller. In Figure 1 In the embodiment, control means 108 and 109 are shown as controlling respective macro-level base stations 106 and 107. The control means of the base stations may be interconnected with other control entities. The control means are typically equipped with storage capacity and at least one data processor. The control means and functions may be distributed among a plurality of control units. In some systems, the control means may additionally or alternatively be arranged in a radio network controller.

[0052] exist Figure 1 In FIG. 1 , base stations 106 and 107 are shown connected to a wider communications network 113 via a gateway 112. A further gateway function may be provided to connect to another network.

[0053] Smaller base stations 116, 118, and 120 may also be connected to the network 113, for example, via a separate gateway function and / or via a controller of a macro-level station. Base stations 116, 118, and 120 may be pico or femto-level base stations, etc. In this example, stations 116 and 118 are connected via gateway 111, while station 120 is connected via controller device 108. In some embodiments, smaller stations may not be provided. Smaller base stations 116, 118, and 120 may be part of a second network, such as a WLAN, and may be WLAN APs.

[0054] The communication devices 102, 104, 105 may access the communication system based on various access technologies, such as code division multiple access (CDMA) or wideband CDMA (WCDMA). Other non-limiting examples include time division multiple access (TDMA), frequency division multiple access (FDMA) and various schemes thereof, such as interleaved frequency division multiple access (IFDMA), single carrier frequency division multiple access (SC-FDMA) and orthogonal frequency division multiple access (OFDMA), space division multiple access (SDMA), etc.

[0055] An example of a wireless communication system is an architecture standardized by the Third Generation Partnership Project (3GPP). Development based on One3GPP is often referred to as the Long Term Evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio access technology. The various development stages of the 3GPP specification are called releases. The latest development of LTE is often referred to as LTE Advanced (LTE-A). LTE (LTE-A) adopts a radio mobile architecture called Evolved Universal Terrestrial Radio Access Network (E-UTRAN) and a core network called Evolved Packet Core (EPC). The base station of such a system is called an evolved or enhanced node B (ENB), and provides E-UTRAN features to communication devices, such as user plane packet data convergence / radio link control / media access control / physical layer protocol (PDCP / RLC / MAC / PHY) and control plane radio resource control (RRC) protocol termination. Other examples of radio access systems include those provided by base stations of systems based on technologies such as wireless local area networks (WLAN) and / or WiMAX (Worldwide Interoperability for Microwave Access). The base station can provide coverage of an entire cell or similar radio service area. The core network elements include the Mobility Management Entity (MME), the Serving Gateway (S-GW) and the Packet Gateway (P-GW).

[0056] An example of a suitable communication system is the 5G or NR concept. The network architecture in NR can be similar to that of LTE-Advanced. The base station of the NR system can be referred to as the next generation node B (gNB). Changes to the network architecture may depend on the need to support various radio technologies and more refined QoS support, as well as some on-demand requirements for QoS levels such as QoE supporting the user's point of view. New functions are defined in the 5G system architecture, including access management function (AMF), session management function (SMF), user plane function (UPF), and other network functions in the next generation core (NGC). The 5G system supports new capabilities, including network slicing, which can better customize the network according to application requirements and provide virtual networks for tenants. It also uses a service-based architecture, which provides greater flexibility for introducing new services and features compared to the EPC that relies on fixed, peer-to-peer reference points. NR can use multiple input multiple output (MIMO) antennas, many more base stations or nodes than LTE (the so-called small cell concept), including macro sites that operate in collaboration with smaller stations, and may also adopt various radio technologies to obtain better coverage and enhanced data rates. Due to the revision of the physical layer and MAC layer protocols, MR can also support lower air interface transmission delay.

[0057] Future networks may utilize network function virtualization (NFV), which is a network architecture concept that proposes virtualizing network node functions into "building blocks" or entities that can be operationally connected or linked together to provide services. A virtualized network function (VNF) may include one or more virtual machines that use standard or general-purpose servers rather than custom hardware to run computer program code. Cloud computing or data storage devices may also be utilized. In radio communications, this may mean that node operations are at least partially performed by a central unit (CU) in a server, host, or node that is operationally coupled to a distributed unit (DU), which may be connected to a remote radio head (RRH). It is also possible that node operations will be distributed among multiple servers, nodes, or hosts. It should also be understood that the distribution of labor between core network operations and base station operations may be different from LTE, or even non-existent.

[0058] Example 5G Core Network (CN) includes functional entities. CN is connected to UE via Radio Access Network (RAN). UPF (User Plane Function) which can be PSA (PDU Session Anchor) that provides anchor point for user IP, Ethernet or unstructured user data session. UPF can be responsible for forwarding frames to and from DN (data network) and gNB through tunnels established on transport network pointing to UE that wants to exchange traffic with DN.

[0059] The UPF is controlled by the SMF (Session Management Function) which receives policies from the PCF (Policy Control Function). The CN may also include an AMF (Access and Mobility Function) which terminates the control plane interface with the RAN and manages UE registration and mobility.

[0060] Now refer to Figure 2 describing in more detail possible mobile communication devices, Figure 2 A schematic, partially cut-away view of a communication device 200 is shown. Such a communication device is often referred to as a user equipment (UE) or terminal. Any device capable of sending and receiving radio signals can provide a suitable mobile communication device. Non-limiting examples include a mobile station (MS) or mobile device, such as a mobile phone or a known "smart phone", a computer equipped with a wireless interface card or other wireless interface facilities (e.g., a USB dongle), a personal digital assistant (PDA) or a tablet computer equipped with wireless communication capabilities, or any combination of these or similar devices. For example, a mobile communication device can provide communications for carrying data such as voice, email (email), text messages, multimedia, etc. Therefore, a variety of services can be supplied and provided to users via their communication devices. Non-limiting examples of these services include two-way or multi-way calls, data communications or multimedia services, or simply access to a data communication network system such as the Internet. Broadcast or multicast data can also be provided to users. Non-limiting examples of content include downloads, television and radio broadcast programs, videos, advertisements, various alarms and other information.

[0061] In industrial applications, the communication device can be a modem integrated into an industrial actuator (e.g., a robotic arm) and / or a modem acting as an Ethernet hub, which will serve as a connection point for one or several connected Ethernet devices (the connection can be wired or non-wired).

[0062] The mobile device is typically equipped with at least one data processing entity 201, at least one memory 202 and other possible components 203 for software and hardware-assisted execution of the tasks it is designed to perform, including control of access and communication to access systems and other communication devices. The data processing, storage and other related control devices may be provided on appropriate circuit boards and / or in chipsets. This feature is represented by reference numeral 204. The user may control the operation of the mobile device through a suitable user interface, such as a keyboard 205, voice commands, a touch screen or touchpad, a combination thereof, etc. A display 208, a speaker and a microphone may also be provided. In addition, the mobile communication device may include appropriate connectors (wired or wireless) to other devices and / or for connecting its external accessories (e.g., a hands-free device).

[0063] The mobile device 200 may receive signals over the air or radio interface 207 via appropriate means for receiving, and may transmit signals via appropriate means for transmitting radio signals. Figure 2 In the embodiment of the present invention, the transceiver arrangement is schematically designated by block 206. The transceiver arrangement 206 may be provided, for example, by a radio component and an associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the mobile device.

[0064] Figure 3 An example embodiment of a control device for a communication system is shown, which is coupled to and / or used to control a station of an access system, such as a RAN node (e.g., a base station, eNB or gNB), a relay node or a core network node (such as an MME or S-GW or P-GW), or a core network function (such as an AMF / SMF), or a server or a host. The method can be implanted in a single control device or across more than one control device. The control device can be integrated with a node or module of a core network or RAN or located outside it. In some embodiments, the base station includes a separate control device unit or module. In other embodiments, the control device can be another network element such as a radio network controller or a spectrum controller. In some embodiments, each base station can have such a control device, such as a CU control plane (CU-CP) and a control device provided in a radio network controller. The control device 300 can be arranged to provide control of communications in a service area of ​​the system. The control device 300 includes at least one memory 301, at least one data processing unit 302, 303 and an input / output interface 304. Via the interface, the control device can be coupled to a receiver and a transmitter of the base station. The receiver and / or the transmitter may be implemented as a radio front end or a remote radio head.

[0065] RRM measurements are used to continuously evaluate the quality of the UE connection and report the results to the NW when specific changes (multiple) in signal conditions are observed. The NW ensures that the UE is connected to the best base station, for example by signal level and quality measurements, by evaluating the measurement reports and requesting a handover to the new cell if the measurements show better coverage from other cells visible to the UE.

[0066] The measurement activities are divided into measurement of (multiple) reference signals, filtering in two levels, physical layer (L1 filtering), then RRC level (L3 filtering) and finally measurement reporting. The measurements, the corresponding processing (filtering) and reporting consume a lot of UE power, which may be unnecessary in good radio conditions. For UEs in low NW traffic areas with low / no interference, in low / semi-static (low mobility) conditions (i.e. with low time and frequency channel variations), there may be a benefit to adapt the measurements to low power consumption with negligible impact on performance.

[0067] The following description is in the context of a 5G communication system and relates to research project RP-181463 “Study on UE Power Saving in NR”.

[0068] It has been agreed that the UE can utilize different power saving schemes specified in 3GPP TR 38.840. A power saving scheme "Power consumption reduction in RRM measurements" is described in Section 5.3 of TR 38.840, in which RRM measurements are adapted to more relaxed requirements if certain conditions are met (e.g., low mobility deployments, low UE speeds, and / or favorable RSRP conditions). The requirements that can be adapted include the measurement period, the number of samples within the measurement period, and the measurement reporting period. Although the TR defines other power saving schemes, the following is described with reference to the measurement adaptation of the measurement requirements. In this application, the term "power saving mode" (PS mode) is used when referring to the relaxation of RRM measurements (or other measurements) under certain conditions.

[0069] Relaxation of intra-frequency and / or inter-frequency measurements under good conditions may include increasing the measurement period. Alternatively or additionally, the number of samples (e.g., OFDM symbols / time slots) within a measurement period (e.g., SMTC window) may be reduced. Alternatively or additionally, RRM measurements may be restricted to within a measurement window, and for intra-frequency and / or inter-frequency measurements, the period of the measurement window is increased.

[0070] To achieve UE power saving, the number of cells used for intra-frequency and inter-frequency measurements may be reduced, assuming that the UE can limit the processing for measurements within a restricted time period and / or with reduced complexity, and assuming that the number of neighboring cells to be measured is reduced. Alternatively or additionally, the need for intra-frequency and inter-frequency measurements of neighboring cells may be reduced.

[0071] However, the reduction of RRM measurements may result in poor service quality and user experience due to poor mobility performance resulting in radio link failure (RLF) and the need for RRC connection re-establishment. Figure 4 Results of a system simulation performed in a dense urban area with 7 sites (3 cells per site, hexagonal grid) with one frequency layer and 50% background interference are shown. In the simulation, the UE measures 5 samples within the measurement period, and the measurement period is varied from 200ms to 3200ms. The UE speeds are 3km / h, 30km / h, 60km / h and 120km / h (corresponding to the lines in ascending order on the graph), and an A3-event trigger time value of 320ms is used. The impact of increasing the measurement period is measured in terms of the number of radio link failures within 40 seconds, as Figure 4 As shown in the figure, if the UE is moving, especially at higher UE speeds, a longer measurement period has a non-negligible impact on the mobility performance (measured in the number of RLFs).

[0072] The current process for radio link failure assessment / declaration is depicted in Figure 5 Whenever the UE fails to decode the PDCCH or PDSCH (control and data channels) due to low RSRP / RSRQ, the UE indicates Out-of-Sync (OoS) to its higher layers and starts counting the number of events related to this in the n310 counter. If the UE detects n310 consecutive OoS indications for a configurable number of frames (e.g., 20 frames (200ms)), it starts the t310 timer while trying to return to synchronization with the network. If the t310 timer expires, the radio link is declared failed and the UE requests RRC connection reestablishment. If the UE detects n311 consecutive In-Sync indications for another configurable number of frames (e.g., 10 frames (100ms)) before the t310 timer expires, the timer stops and the link is not failed.

[0073] The timers and constants t310, n310 and n311 are configured in rlf-TimersAndConstants and can have the following values:

[0074] -t310 enumerate {ms0,ms50,ms100,ms200,ms500,ms1000,ms2000,ms4000,ms6000},

[0075] -n310 enumerate {n1,n2,n3,n4,n6,n8,n10,n20},

[0076] -n311 enumerate {n1,n2,n3,n4,n5,n6,n8,n10},

[0077] Reference Figure 5 The described procedure is independent of whether the UE is in PS mode or not, and there is no measure to prevent or limit higher RLF occurrences due to the adaptation of the measurements. The QoS degradation caused by relaxed measurement requirements is significant and can probably only be avoided (or the performance degradation accepted) by keeping the relaxation at a moderate level. Therefore, by introducing power saving methods, either incurring mobility performance degradation or by using very moderate measurement adaptation to avoid increasing RLF failures, the potential power saving gains are limited.

[0078] That is, the adaptation of the measurements increases the periodicity of the measurements and / or reduces the number of samples and / or the number of reports generated by these measurements. Due to the measurement delays introduced at higher UE speeds, their quality or lost timely reporting, RLF may occur even before the A3 event is triggered. Therefore, an increase in RLF may be observed.

[0079] Figure 6 A flow chart of a method according to an example embodiment is shown in FIG.

[0080] In a first step, the method comprises operating using a first measurement configuration.

[0081] In a second step, the method comprises determining that a first trigger condition associated with at least one radio link failure indicator is met.

[0082] In a third step, the method includes, in response to the determination, operating using a second measurement configuration until a second trigger condition is met, wherein operating using the second measurement configuration includes at least one of the following operations: performing measurements with reduced periodicity, an increased number of samples and / or an increased number of reports, increasing the number of neighbor cells measured, or reducing the trigger time switching period relative to the first measurement configuration.

[0083] The first and / or second measurement configuration may be an RRM measurement and reporting configuration. The configuration may be configured by the network or configured internally in the UE (ie, independent of the network).

[0084] In an example embodiment, in the second measurement configuration, one or more measurement or mobility parameters may be scaled as described below.

[0085] The measurement distance may be reduced relative to the value in the first measurement configuration mode (e.g., to 40ms). This parameter may potentially scale with the speed of the UE, since a low distance may have a negative impact in measurements of stationary (e.g., 0km / h) and pedestrian (e.g., 3km / h) UEs. On the other hand, for medium to high speed UEs, channel conditions change quickly, so a short distance will improve the UE's ability to capture changes.

[0086] A maximum number of samples can be applied. The measurement accuracy can be improved as the number of samples increases.

[0087] A maximum number of measurement reports may apply.If any reporting is skipped for power saving in the first measurement configuration, the UE may miss notifying the NW to trigger A3 due to lack of knowledge of the recent channel change.

[0088] The A3 trigger time (TTT) can be reduced. A quick reaction to the A3 trigger to switch to a better cell can prevent the UE from staying in a cell with poor conditions for too long.

[0089] The UE may scan the antenna ports / configurations and adapt.

[0090] The first measurement configuration may be a power saving mode with loose / adaptive measurement configuration as described above. The adapted / loose measurement configuration based on the corresponding UE power saving scheme is referred to as a "measurement adaptation state".

[0091] Alternatively, the first measurement configuration may be a "measurement normal state", such as a Release 15 measurement configuration as described above.

[0092] The second measurement configuration may be referred to as a "measurement resumption state". The resumption state is a measurement state in which the UE performs more aggressive measurements to verify conditions. By having this resumption state, the UE may be able to compensate for the lack of measurements in one of the other states.

[0093] Figure 7 Three measurement states and the transitions between them are shown. Entry and exit criteria for the UE to move to the Adaptation state and back to the Normal state are being defined, namely C1 and C2. The triggering conditions for the UE to move between the "Measurement Adaptation state" and the "Measurement Resumption state" are C3 and C4. The triggering conditions for the UE to move between the "Measurement Normal state" and the "Measurement Resumption state" are C5 and C6.

[0094] A first trigger condition associated with at least the RLF indicator may include an indication of an upcoming RLF, such as an RLF counter n310 (potentially a newly defined n310 when the UE is in PS mode (PS_n310) where PS_310 is lower than n310 to assist in faster recovery) or an RLF timer t310, or at least one of: determining that the reference signal received power is lower than a first threshold, determining a decoding failure of a physical downlink control channel or a physical downlink shared channel, performing new cell discovery, and determining the disappearance of a known cell.

[0095] The indicators used to predict an upcoming failure are the same as those used for the RLF procedure itself, i.e., lost decoding of PDCCH or PDSCH due to RSRP being too low. Alternatively or in addition, there may be other points or triggers for the UE to operate using the second measurement configuration, such as a change in the measurement exceeding a certain threshold (indicating an unstable radio channel), new cells being discovered (where having detailed information available quickly is beneficial), situations where strong cells are disappearing (for situations where a channel is not guaranteed, such as NR operation in unlicensed bands, NR-U), etc.

[0096] The NW may define a new counter value, PS_n310<=n310 (NW assisted), or the UE may autonomously determine to use the second measurement configuration.

[0097] The method may include operating using a second set of measurement parameters after the first counter value is met or after expiration of a timer after determining that the first trigger condition is met.For example, the NW may configure a timer t310 for measuring the adaptation state (PS_n310).

[0098] Alternatively or additionally, the UE may make its own decision after starting the n310 counter.

[0099] The idea is to have the UE start the recovery state in time to be able to recover from the OoS, therefore, no later than the start of the t310 timer.

[0100] Depending on when the UE begins operating using the second measurement configuration, the UE has a minimum t310 seconds to get back into synchronization with the NW and help cancel t310 before it expires and RLF is declared. The method may include performing a synchronization attempt while the apparatus is operating using the second measurement configuration. That is, the measurement recovery state runs in parallel with the triggering activity from the UE related to the RLF process.

[0101] The second trigger condition may include at least one of a reset of a radio link failure timer, a radio link failure, and usage of the first amount of resources.

[0102] For example, when the UE spends a given amount of resources in the measurement resumption state, the UE may transition to one of the other two states. The first amount of resources spent in the measurement resumption state may be defined as a measurement amount, a specific time, or by other means.

[0103] exist Figure 7 In the embodiment, the transition marks for leaving the measurement recovery state are C4 and C6, which are used to transition to the adaptation state and the normal state respectively. The condition for exiting the recovery state can be based on the number of defined synchronization conditions, or based on other means for determining whether the radio conditions require declaring RLF.

[0104] After the second trigger condition is met, the user equipment may operate using the first measurement configuration or the third measurement configuration. That is, the UE may return to the measurement adaptation state or the measurement normal state in which it operated before the measurement resumption state, or it may return to another state in these states.

[0105] Figure 8 The UE is shown moving to the Measurement Recovery state when the first trigger condition is met. The NW updates n310 to "PS Mode Failure Constant (PS_n310)". When an OoS condition is detected, and based on PS_n310 or local decision, the Measurement Recovery state is entered. t310 starts after n310, and the UE attempts to use RACH to return to synchronization with the cell.

[0106] Fig. 9 It shows that Figure 8 The UE is shown moving to the Measurement Resumption state. In this figure, the UE in the Measurement Resumption state can return to synchronization with the NW before t310 expires. t310 is reset and the UE returns to the Measurement Adaptation state.

[0107] Each scaled parameter may improve the UE's ability to capture the conditions of its serving cell compared to its neighbor cells and / or enable the NW to trigger A3 and react faster than in the measurement adaptation state. The idea is that the UE should be very aggressive in order to be able to prevent RLF before t310 expires.

[0108] Fig. 9 It shows that Figure 8 The UE is shown moving to the Measurement Resumption state. In this figure, the UE in the Measurement Resumption state can return to synchronization with the NW before t310 expires. t310 is reset and the UE returns to the Measurement Adaptation state.

[0109] During the measurement resumption state, UE power consumption may increase, but the increased power is expected to be negligible compared to the power savings achieved with more aggressive easing in the measurement adaptation state.

[0110] The measurement resumption state should be considered an intermediate state where the UE is performing extraordinary measurements to allow for improved accuracy or to increase information to recover from a lack of available measurements in the past. Figure 3 As shown, the transitions out of this state are marked with C4 and C6, which are used to transition to the adapted state and the normal state, respectively. The conditions for exiting the recovery state can be based on a defined number of synchronization conditions (such as Fig. 9 ) or based on other means for determining whether radio conditions require declaring RLF.

[0111] The method as described above addresses mobility performance degradation that may be caused by UE power saving based on UE measurement adaptation, and proposes a solution with early detection of impending degradation and countermeasures to reduce or completely prevent negative impacts. The method can be applied to any other situation where significant changes in the channel are observed without the UE being in PS mode. Compared to the first measurement configuration, the proposed recovery mode (i.e., the second measurement configuration) attempts to compensate for the measurement configuration using more aggressive measurements and / or general scaling of mobility parameters before RLF occurs or is declared.

[0112] The second measurement configuration scales the measurements and / or other mobility parameters to introduce a fast recovery mechanism before declaring or avoiding RLF. The second measurement configuration may compensate for reduced measurement accuracy that may result in more radio link failures due to, for example, relaxation of measurement requirements in the first measurement configuration including a measurement adaptation state.

[0113] Although in the above the recovery state is primarily described as compensating for any negative mobility effects caused by the measurement adaptation state, the measurement recovery state may also be used as a countermeasure to the degradation seen in the measurement normal state when rapid time and frequency channel variations are observed.

[0114] This method can be found in the reference Figure 2 Describes the user device or reference Figure 3 The control device described is implemented in the embodiment of the present invention.

[0115] An apparatus may include components for operating using a first measurement configuration, determining that a first trigger condition associated with at least a radio link failure indicator is met, and in response to the determination, operating using a second measurement configuration until a second trigger condition is met, wherein operating using the second measurement configuration includes at least one of the following operations: performing measurements with reduced periodicity, an increased number of samples and / or an increased number of reports, increasing the number of neighbor cells measured, and reducing the time used to trigger a switching cycle relative to the first measurement configuration.

[0116] It should be understood that these devices may include or be coupled to other units or modules used in transmission and / or reception, such as radio components or radio heads, etc. Although these devices have been described as one entity, different modules and memories may be implemented in one or more physical or logical entities.

[0117] Note that while the embodiments have been described in relation to 5G NR, similar principles may be applied in relation to other networks and communication systems. Thus, while certain embodiments are described above by way of example with reference to certain example architectures for wireless networks, technologies and standards, the embodiments may be applied to any other suitable form of communication system in addition to those shown and described herein.

[0118] It is also noted herein that while the above describes exemplifying embodiments, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention.

[0119] In general, the various example embodiments may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects of the invention may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device, although the invention is not limited thereto. Although various aspects of the invention may be shown and described as block diagrams, flow charts, or using some other graphical representation, it is understood that the blocks, devices, systems, techniques, or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, dedicated circuits or logic, general purpose hardware or controllers or other computing devices, or some combination thereof.

[0120] Example embodiments of the present invention may be implemented by computer software executable by a data processor of a mobile device, such as in a processor entity, or by hardware, or by a combination of software and hardware. Computer software or programs (also referred to as program products), including software routines, applets and / or macros, may be stored in any device-readable data storage medium, and they include program instructions for performing specific tasks. A computer program product may include one or more computer executable components that are configured to perform an embodiment when the program is run. The one or more computer executable components may be at least one software code or a portion thereof.

[0121] Furthermore, it should be noted in this regard that any block of the logic flow as in the figure may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on physical media such as memory chips or memory blocks implemented within a processor, magnetic media such as hard disks or floppy disks, and optical media such as DVDs and their data variants (CDs). Physical media are non-transitory media.

[0122] The memory may be of any type suitable for the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based storage devices, magnetic storage devices and systems, optical storage devices and systems, fixed memory, and removable memory. The data processor may be of any type suitable for the local technical environment and may include one or more of the following: a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an FPGA, a gate-level circuit, and a processor based on a multi-core processor architecture, as non-limiting examples.

[0123] Example embodiments of the present invention may be implemented in various components such as integrated circuit modules. The design of integrated circuits is generally a highly automated process. Complex and powerful software tools are available to convert logic level designs into semiconductor circuit designs ready to be etched and formed on semiconductor substrates.

Claims

1. An apparatus for communication, comprising means for: operating using the first measurement configuration or the third measurement configuration; determining that at least a first trigger condition associated with a radio link failure indicator is satisfied; as well as In response to the determining, operating using a second measurement configuration until a second trigger condition is met, wherein operating using the second measurement configuration comprises at least one of: performing measurements with reduced periodicity, an increased number of samples, and / or an increased number of reports, increasing the number of neighbor cells measured, and reducing a time to trigger a switching cycle relative to the first measurement configuration; The first measurement configuration is a measurement configuration of the user equipment in a normal measurement state, the second measurement configuration is a measurement configuration of the user equipment in a measurement recovery state, and the third measurement configuration is a measurement configuration of the user equipment in a measurement adaptation state; wherein in the second measurement configuration, one or more measurement parameters or mobility parameters are scaled; wherein the second trigger condition comprises at least one of the following: a reset of a radio link failure timer, a radio link failure, and use of a first amount of resources; The device further comprises: means for performing a synchronization attempt while the apparatus is operating using the second measurement configuration; as well as Means for operating using the first measurement configuration or the third measurement configuration after a second trigger condition is met. 2 . The apparatus of claim 1 , wherein the first measurement configuration is a power save measurement configuration.

3. The apparatus of claim 1 or claim 2, wherein the first measurement configuration and the second measurement configuration comprise radio resource management measurement and reporting configurations.

4. The apparatus according to claim 1 or claim 2, wherein the radio link failure indicator comprises at least one of the following: Radio link failure counter; Radio link timer; Determining that a reference signal received power is lower than a first threshold; Determining that decoding of a physical downlink control channel or a physical downlink shared channel fails; performing new cell discovery; and Determine the disappearance of known cells.

5. An apparatus according to claim 1 or claim 2, comprising means for operating using the second measurement configuration after a first counter value is satisfied or after expiration of a timer after determining that the first trigger condition is satisfied.

6. A method for communication, comprising: operating using a first measurement configuration or a third measurement configuration; determining that at least a first trigger condition associated with a radio link failure indicator is satisfied; as well as In response to the determination, operating using a second measurement configuration until a second trigger condition is met, wherein operating using the second measurement configuration comprises at least one of: performing measurements with reduced periodicity, an increased number of samples, and / or an increased number of reports, increasing the number of neighbor cells measured, and reducing a time to trigger a switching cycle relative to the first measurement configuration; The first measurement configuration is a measurement configuration of the user equipment in a normal measurement state, the second measurement configuration is a measurement configuration of the user equipment in a measurement recovery state, and the third measurement configuration is a measurement configuration of the user equipment in a measurement adaptation state; wherein in the second measurement configuration, one or more measurement parameters or mobility parameters are scaled; wherein the second trigger condition comprises at least one of the following: a reset of a radio link failure timer, a radio link failure, and use of a first amount of resources; The method further comprises: performing a synchronization attempt while operating using the second measurement configuration; as well as After a second trigger condition is met, operating using the first measurement configuration or the third measurement configuration.

7. An apparatus for communication, comprising: at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured, with the at least one processor, to cause the apparatus to at least: operating using the first measurement configuration or the third measurement configuration; determining that at least a first trigger condition associated with a radio link failure indicator is satisfied; as well as In response to the determination, operating using a second measurement configuration until a second trigger condition is met, wherein operating using the second measurement configuration comprises at least one of: performing measurements with reduced periodicity, an increased number of samples, and / or an increased number of reports, increasing the number of neighbor cells measured, and reducing a time to trigger a switching cycle relative to the first measurement configuration; The first measurement configuration is a measurement configuration of the user equipment in a normal measurement state, the second measurement configuration is a measurement configuration of the user equipment in a measurement recovery state, and the third measurement configuration is a measurement configuration of the user equipment in a measurement adaptation state; wherein in the second measurement configuration, one or more measurement parameters or mobility parameters are scaled; wherein the second trigger condition comprises at least one of the following: a reset of a radio link failure timer, a radio link failure, and use of a first amount of resources; The at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus to at least: performing a synchronization attempt while the apparatus is operating using the second measurement configuration; as well as After a second trigger condition is met, operating using the first measurement configuration or the third measurement configuration.

8. A computer-readable medium comprising program instructions, wherein the program instructions are used to cause an apparatus to perform at least the following operations: operating using the first measurement configuration or the third measurement configuration; determining that at least a first trigger condition associated with a radio link failure indicator is satisfied; as well as In response to the determination, operating using a second measurement configuration until a second trigger condition is met, wherein operating using the second measurement configuration comprises at least one of: performing measurements with reduced periodicity, an increased number of samples, and / or an increased number of reports, increasing the number of neighbor cells measured, and reducing a time to trigger a switching cycle relative to the first measurement configuration; The first measurement configuration is a measurement configuration of the user equipment in a normal measurement state, the second measurement configuration is a measurement configuration of the user equipment in a measurement recovery state, and the third measurement configuration is a measurement configuration of the user equipment in a measurement adaptation state; wherein in the second measurement configuration, one or more measurement parameters or mobility parameters are scaled; wherein the second trigger condition comprises at least one of the following: a reset of a radio link failure timer, a radio link failure, and use of a first amount of resources; performing a synchronization attempt while the apparatus is operating using the second measurement configuration; as well as After a second trigger condition is met, operating using the first measurement configuration or the third measurement configuration.

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