Patent Description:
In 3GPP Rel-<NUM> (third generation project, release <NUM>), reduced capability (RedCap) UEs will be introduced. See, e.g., <NPL>. The intended use cases for RedCap UEs include the following.

The study item (RP-<NUM>) has the following objective:.

Study UE power saving and battery lifetime enhancement for reduced capability UEs in applicable use cases (e.g. delay tolerant):.

One issue with these reduced capability UEs is determining stationarity of the devices.

<CIT> describes methods for performing measurements in different periods by a user equipment being in a discontinuous reception mode. These periods have different frequency and dependent on measured signal strengths.

<CIT> describes cell measurements which are periodic or trigger event based. The measurements may be suspended based on signal quality and cell changes.

<CIT> describes methods for performing measurements by mobile terminal devices. These measurements are scheduled based on repetition periods.

This section is intended to include examples and is not intended to be limiting.

Abbreviations that may be found in the specification and/or the drawing figures are defined below, at the end of the detailed description section.

The exemplary embodiments herein describe techniques for dynamic UE signal level correction for stationarity detection. Additional description of these techniques is presented after a system into which the exemplary embodiments may be used is described.

Turning to <FIG>, this figure shows a block diagram of one possible and non-limiting exemplary system in which the exemplary embodiments may be practiced. A user equipment (UE) <NUM>, radio access network (RAN) node <NUM>, and network element(s) <NUM> are illustrated. In <FIG>, a user equipment (UE) <NUM> is in wireless communication with a wireless network <NUM>. A UE is a wireless, typically mobile device that can access a wireless network. The UE <NUM> includes one or more processors <NUM>, one or more memories <NUM>, and one or more transceivers <NUM> interconnected through one or more buses <NUM>. The one or more buses <NUM> may be address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, and the like. The UE <NUM> includes a control module <NUM>, comprising one of or both parts <NUM>-<NUM> and/or <NUM>-<NUM>, which may be implemented in a number of ways. The control module <NUM> may be implemented in hardware as control module <NUM>-<NUM>, such as being implemented as part of the one or more processors <NUM>. The control module <NUM>-<NUM> may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the control module <NUM> may be implemented as control module <NUM>-<NUM>, which is implemented as computer program code <NUM> and is executed by the one or more processors <NUM>. For instance, the one or more memories <NUM> and the computer program code <NUM> may be configured to, with the one or more processors <NUM>, cause the user equipment <NUM> to perform one or more of the operations as described herein. The UE <NUM> communicates with RAN node <NUM> via a wireless link <NUM>.

The RAN node <NUM> is a base station that provides access by wireless devices such as the UE <NUM> to the wireless network <NUM>. In the text below, the term "base station" (or BS) is also used for the RAN node <NUM>. The RAN node <NUM> may be, for instance, a base station for <NUM>, also called New Radio (NR). In <NUM>, the RAN node <NUM> may be a NG-RAN node, which is defined as either a gNB or an ng-eNB. A gNB is a node providing NR user plane and control plane protocol terminations towards the UE, and connected via the NG interface to a 5GC (e.g., the network element(s) <NUM>). The ng-eNB is a node providing E-UTRA user plane and control plane protocol terminations towards the UE, and connected via the NG interface to the 5GC. The NG-RAN node may include multiple gNBs, which may also include a central unit (CU) (gNB-CU) <NUM> and distributed unit(s) (DUs) (gNB-DUs), of which DU <NUM> is shown. Note that the DU may include or be coupled to and control a radio unit (RU). The gNB-CU is a logical node hosting RRC, SDAP and PDCP protocols of the gNB or RRC and PDCP protocols of the en-gNB that controls the operation of one or more gNB-DUs. The gNB-CU terminates the F1 interface connected with the gNB-DU. The F1 interface is illustrated as reference <NUM>, although reference <NUM> also illustrates a link between remote elements of the RAN node <NUM> and centralized elements of the RAN node <NUM>, such as between the gNB-CU <NUM> and the gNB-DU <NUM>. The gNB-DU is a logical node hosting RLC, MAC and PHY layers of the gNB or en-gNB, and its operation is partly controlled by gNB-CU. One gNB-CU supports one or multiple cells. One cell is supported by one gNB-DU. The gNB-DU terminates the F1 interface <NUM> connected with the gNB-CU. Note that the DU <NUM> is considered to include the transceiver <NUM>, e.g., as part of an RU, but some examples of this may have the transceiver <NUM> as part of a separate RU, e.g., under control of and connected to the DU <NUM>. The RAN node <NUM> may also be an eNB (evolved NodeB) base station, for LTE (long term evolution), or any other suitable base station.

The RAN node <NUM> includes a control module <NUM>, comprising one of or both parts <NUM>-<NUM> and/or <NUM>-<NUM>, which may be implemented in a number of ways. The control module <NUM> may be implemented in hardware as control module <NUM>-<NUM>, such as being implemented as part of the one or more processors <NUM>. The control module <NUM>-<NUM> may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the control module <NUM> may be implemented as control module <NUM>-<NUM>, which is implemented as computer program code <NUM> and is executed by the one or more processors <NUM>. For instance, the one or more memories <NUM> and the computer program code <NUM> are configured to, with the one or more processors <NUM>, cause the RAN node <NUM> to perform one or more of the operations as described herein. Note that the functionality of the control module <NUM> may be distributed, such as being distributed between the DU <NUM> and the CU <NUM>, or be implemented solely in the DU <NUM>.

Two or more RAN nodes <NUM> communicate using, e.g., link <NUM>. The link <NUM> may be wired or wireless or both and may implement, e.g., an Xn interface for <NUM>, an X2 interface for LTE, or other suitable interface for other standards.

The one or more buses <NUM> may be address, data, or control buses, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, wireless channels, and the like. For example, the one or more transceivers <NUM> may be implemented as a remote radio head (RRH) <NUM> for LTE or a distributed unit (DU) <NUM> for gNB implementation for <NUM>, with the other elements of the RAN node <NUM> possibly being physically in a different location from the RRH/DU, and the one or more buses <NUM> could be implemented in part as, e.g., fiber optic cable or other suitable network connection to connect the other elements (e.g., a central unit (CU), gNB-CU) of the RAN node <NUM> to the RRH/DU <NUM>. Reference <NUM> also indicates those suitable network link(s).

The wireless network <NUM> may include a network element or elements <NUM> that may include core network functionality, and which provides connectivity via a link or links <NUM> with a data network <NUM>, such as a telephone network and/or a data communications network (e.g., the Internet). Such core network functionality for <NUM> may include access and mobility management function(s) (AMF(s)) and/or user plane functions (UPF(s)) and/or session management function(s) (SMF(s)). Such core network functionality for LTE may include MME (Mobility Management Entity)/SGW (Serving Gateway) functionality. These are merely exemplary functions that may be supported by the network element(s) <NUM>, and note that both <NUM> and LTE functions might be supported. The RAN node <NUM> is coupled via a link <NUM> to a network element <NUM>. The link <NUM> may be implemented as, e.g., an NG interface for <NUM>, or an S1 interface for LTE, or other suitable interface for other standards. The network element <NUM> includes one or more processors <NUM>, one or more memories <NUM>, and one or more network interfaces (N/W I/F(s)) <NUM>, interconnected through one or more buses <NUM>. The one or more memories <NUM> and the computer program code <NUM> are configured to, with the one or more processors <NUM>, cause the network element <NUM> to perform one or more operations.

It is noted that description herein indicates that "cells" perform functions, but it should be clear that the base station that forms the cell will perform the functions. The cell makes up part of a base station. That is, there can be multiple cells per base station. For instance, there could be three cells for a single carrier frequency and associated bandwidth, each cell covering one-third of a <NUM>-degree area so that the single base station's coverage area covers an approximate oval or circle. Furthermore, each cell can correspond to a single carrier and a base station may use multiple carriers. So, if there are three <NUM>-degree cells per carrier and two carriers, then the base station has a total of <NUM> cells.

In the example of <FIG>, a "cell" <NUM> is illustrated, having an outer region <NUM> (including an edge <NUM> of the cell) and an inner region <NUM> (including a center <NUM> of the cell). For instance, the inner region <NUM> may be a known region within some set distance from the center <NUM> of the cell <NUM>, and the outer region <NUM> may be a known region within some set distance from the edge <NUM> of the cell <NUM>. These terms are used below to describe effects that occur in in these locations. Note also that this "cell" <NUM> may be three individual, <NUM>-degree cells as described above, but for ease of reference, the cell <NUM> is shown as an oval.

The computer readable memories <NUM>, <NUM>, and <NUM> may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The computer readable memories <NUM>, <NUM>, and <NUM> may be means for performing storage functions. The processors <NUM>, <NUM>, and <NUM> may be of any type suitable to the local technical environment, and may include one or more of general-purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on a multi-core processor architecture, as non-limiting examples. The processors <NUM>, <NUM>, and <NUM> may be means for performing functions, such as controlling the UE <NUM>, RAN node <NUM>, and other functions as described herein.

In general, the various embodiments of the user equipment <NUM> can include, but are not limited to, cellular telephones such as smart phones, tablets, personal digital assistants (PDAs) having wireless communication capabilities, portable computers having wireless communication capabilities, vehicles with a modem device for wireless V2X (vehicle-to-everything) communication, image capture devices such as digital cameras having wireless communication capabilities, gaming devices having wireless communication capabilities, music storage and playback appliances having wireless communication capabilities, Internet appliances (including Internet of Things, IoT, devices) permitting wireless Internet access and possibly browsing, IoT devices with sensors and/or actuators for automation applications with wireless communication tablets with wireless communication capabilities, as well as portable units or terminals that incorporate combinations of such functions.

Having thus introduced one suitable but non-limiting technical context for the practice of the exemplary embodiments, the exemplary embodiments will now be described with greater specificity.

Before proceeding to describe the exemplary embodiments, it is helpful to provide an overview of this technological area. Some technical standards do not describe determining whether a UE is stationary, but there is the related concept of "mobility", including "low mobility". For instance, it is specified in 3GPP TS <NUM> (see <NPL>)) that UEs use received signal strength to detect what their mobility states are. The physical layer details are in 3GPP TS <NUM>. Further details on signaling can also be found in 3GPP TS <NUM>. In 3GPP TS <NUM>, low mobility is not discussed, but instead normal/medium/high mobility are introduced. The low mobility introduced in 3GPP TS <NUM> is an extension of the mobility concepts in 3GPP TS <NUM>. In these schemes, a UE compares its received signal strength to a cell specific signal variation parameter broadcast by the BS. The stationarity detection has been problematic in LTE for UEs in the outer region <NUM> (e.g., a cell edge <NUM>) of the cells and also in the inner region <NUM> (including the cell center <NUM>) of the cells <NUM>, as the UEs observe different signal variations. With the introduction of NR, there are many novel factors introduced that affect the UE's signal strength variation, such as antenna types, device capabilities and many more. Thus, with NR, it is generally not possible to detect stationarity via a cell specific variation parameter for a wider range of UEs.

With reference to <FIG>, this figure is an illustration of the variation of the path loss and shadowing with time in an In Factory Dense Clutter Low Base Station scenario as described in 3GPP TS <NUM>, where two UEs are stationary between at distance <NUM> meters (see InF_DL_channel_loss_edge) and <NUM> meters (see InF_DL_channel_loss_center) to the BS. In <FIG>, a scenario with a cell radius of <NUM> with the shadowing and path loss exponents as specified in TR <NUM> is illustrated. Two UEs are stationary, one close to the cell edge <NUM> and one close to the cell center <NUM>, at distances <NUM> and <NUM> to the BS, respectively. A measurement is performed each <NUM> as depicted by the x-axis. The y-axis depicts the path loss in dB. The curve marked as InF_DL_channel_loss_edge depicts the path loss and shadowing observed for close to cell edge UE and the curve marked InF_DL_channel_loss_center depicts the path loss and shadowing observed for close to cell center UE. The standard deviations of signal strength of both scenarios are depicted on the curve as <NUM> (σ<NUM>) and <NUM> (σ<NUM>), respectively. The main reason for this is that the LoS probability decreases with increasing distance to the base station. The standard deviation of LoS shadowing is a lot lower compared to NLoS shadowing (not shown in <FIG>), <NUM> and <NUM>, respectively. The amount of variation will strictly depend on the cell settings.

<NUM>) In another example of the problem, a UE1 with an omnidirectional antenna that is rotating in a (e.g., somewhat) fixed position would experience no change in its measurements while a UE2 with directional antenna would experience sudden changes in measurements due to its rotation. <FIG> illustrates the antenna radiation pattern <NUM> of an omnidirectional UE <NUM>, while <FIG> illustrates the antenna radiation pattern <NUM> of a multipanel UE <NUM>.

In more detail, the UEs are expected to deploy various antenna types out of which may be the omnidirectional antenna (<FIG>) and a multipanel antenna (<FIG>). In the omni antenna (i.e., omnidirectional antenna) case in <FIG> with a UE <NUM>-<NUM>, it is clear that when a UE <NUM>-<NUM> is stationary, irrespective of its rotation, the received power will be similar. However, for a multipanel UE <NUM>-<NUM> of <FIG>, the rotation will impact the signal power observed and can hinder the stationarity detection. This will be particularly specific to the radiation pattern of the antenna and the behavior of the UE. Similarly, base stations are already located with many antenna types that are configured in multiple ways physically and electronically. Thus, UE-specific and a cell-specific variation is expected.

In both of these scenarios, the BS has the following two choices.

Furthermore, these examples are not exhaustive, and a scenario-specific variation of the signal level can be extended to other scenarios. These embodiments can be extended and reliable stationarity detection cannot be achieved in many scenarios. Detection of stationarity is needed for radio measurement relaxation, RAN notification area update, tracking area update and many signaling procedures to cover the problems that can be raised by the mobility of the UE. Measurement relaxation allows the UE to perform fewer measurements over time (e.g., than currently performed under a current configuration), such as the UE will perform measurements less frequently, the UE is allowed to skip some measurements, the UE is allowed to determine when to perform measurements, and/or the UE will measure fewer cells or frequencies. It is also noted that "measurement relaxation" may include the "relaxed measurements" in, e.g., 3GPP TS <NUM> or other technical standards.

Importantly, such problems cannot be solved only at the UE side, as the variations are affected by the cell settings. That is, the BS has to communicate additional parameters to achieve stationary detection.

With respect to exemplary embodiments herein, first an overview is provided, then more details are provided. As an overview, exemplary embodiments herein include a method in, e.g., cellular networks for a UE to detect if the UE is stationary or not. The method involves a cell specific signal variation parameter and a high/medium variation parameter calculated and broadcast by a BS in a cell and a UE detecting if the UE has high signal variation or not. One exemplary idea is to group the variations seen by different UEs as low, medium and high signal variations. The BS broadcasts a signal variation parameter corresponding to each of the three variation groups. Three new parameters are defined, in an exemplary embodiment, as part of the new stationarityEvaluation configuration: SSearchDeltaP (different from a legacy value defined in lowMobilityEvaluation), stationary_UE_medium_variation_correction, and stationary_UE_high_variation_correction. These are described in more detail below, but can be used to place the UE into one of the three variation groups. Each UE identifies itself to be in one of these three variation groups and will use the corresponding variation parameter to detect stationarity. Note that using three variation groups is merely exemplary, and fewer or more groups could be used.

Exemplary operations may include the following.

Now that an overview has been provided, additional details are provided. For ease of reference, the rest of this document is divided into labeled sections. The labeling is merely for reference and is not intended to be limiting.

The table in <FIG> summarizes parameters and events that would affect the setting of aforementioned parameter. <FIG> is referred to as Table <NUM>, and illustrates cell specific occurrences that may cause high variation. The columns indicate the parameter event, the high UE variation, the low UE variation, and why these are cell-specific. The rows are for the following: <NUM>, LoS/NLoS shadowing; <NUM>, UE rotation; and <NUM>, measurement accuracy.

In the following sections, UE variation scenarios are detailed. Initially, the reasons for observing UE-specific variations are explained. This is followed by the explanation of why each problem can be solved by a parameter broadcast from the BS and cannot be solved by UE by itself.

Increasing the distance to the base station <NUM> decreases the probability of a LoS path to the BS <NUM>. Consequently, a UE <NUM> near the edge <NUM> of the cell <NUM> will have mostly NLoS to the BS.

Another important piece of information is the effect of shadowing with respect to LoS and NLoS. Shadowing causes the signal received by the UE to fluctuate. Typically, with NLoS, a UE <NUM> has higher variations compared to LoS variations. Shadowing is the effect of an object blocking the electro-magnetic signals, e.g., like the sun rays, resulting in a shadow. As the signal is reflected from many different objects, there is not a complete blockage of the electro-magnetic signal, but decreasing its strength.

Thus, combining these two pieces of information, one can see that a UE that is further away from the BS observes higher signal variation compared to the UE that is closer to the BS.

However, one can argue that the UE can detect its distance to the BS and correct this change in signal variation. This would be true if the amount of variations would not depend on the cell settings. Referring to <FIG>, this figure is an illustration of path loss and shadowing of a stationary UE for two different cell settings. The curve labeled as "InF_DL_channel_loss" depicts a dense clutter of machines in a factory environment with a BS located in the clutter. The bracket on the right is used to indicate a "main" portion of the curve. Meanwhile, the curve "InF_SH_channel_loss" depicts a dense clutter of machines with a BS located above the clutter in a factory environment. The bracket on the right is used to indicate a "main" portion of the curve. It is noted, therefore, that cell-specific variation can be perceived differently for different UE types.

It can be seen that even if all the UE parameters are kept the same except the cell settings, the variations observed by two UEs are different as emphasized by the standard deviations, <NUM> (σ<NUM>) and <NUM> (σ<NUM>) in sparse and dense clutters, respectively. This emphasizes the need of a variation parameter by each BS depending on the cell settings.

The UEs are expected to deploy various antenna types, out of which may be the omnidirectional antenna and a multipanel antenna. In the omni antenna case, it is clear that when a UE is stationary, irrespective of its rotation, the received power will be similar. However, for a multipanel UE, some physical rotation of the UE will impact the signal power observed and can hinder the stationarity detection. This will be particularly specific to the radiation pattern of the antenna and the behavior of the UE.

Similarly, base stations are already located with many antenna types that are configured in multiple ways physically and electronically. Thus, the matching between the UE and the BS antenna type will play an important role with respect to each cell.

There are many factors that can affect the measurement accuracy of a UE. Some of these can be related to implementation, while some are related to the BW allocated to the UE by the network. Intuitively, the wider bandwidth that is used for measurements, the more precise the measurements are for the UE.

Similar to the first scenario in section <NUM>, the amount of variations with respect to the measurement accuracy will depend on the cell settings.

The methodology to set the parameters of stationary_UE_high/medium_variation_correction can follow the logic used to set SSearchDeltaP (which is currently considered in the specifications). Below are additional processes to set this parameter.

Note that one BS <NUM> can communicate the information in this section between this base station and other base station(s) and can coordinate setting the values for high/medium variations. For instance, the values of stationary_UE_high/medium_variation_correction can be communication from this base station to other base stations during the processes above, and this could help coordination to set these values.

The UE variation detection merges cell-specific measurements with UE configuration.

As independent embodiments causing higher perceived signal level variation for the UE can occur, the UE should merge these cases to adjust its variation correction parameter, as illustrated in <FIG> is a flowchart illustrating the UE's decision of low, medium or high variation, in accordance with an exemplary embodiment. <FIG> illustrates the operation of exemplary methods, a result of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and/or interconnected means for performing functions in accordance with exemplary embodiments. <FIG> is performed by a UE <NUM>, e.g., under control of a control module <NUM>, at least in part.

The flow starts <NUM> and in block <NUM>, the UE <NUM> determines if the UE is configured to have high variation. The process for this determination is referred to as "subroutine <NUM>".

That is, the UE initially checks if it is configured for high variation through subroutine <NUM>. Subroutine <NUM> involves the UE's capabilities, including, e.g., physical and software configurations, that can lead to high variation. One example can be the antenna type of the UE and can be set as a flag in the decision mechanism. That is "if antenna type is multi-panel, set high variation to true". Different UEs have different numbers of antennas, this can be a physical configuration and provide different capability. Also, some UEs may disable the use of some antennas through software configuration even though they physically have those antennas, and this also is a capability of the UE. That would be an example of software configuration. Similar examples can be given for bandwidth, half duplexing and so on, as examples of capabilities of the UE. The measurement accuracy is again a configuration of the device and this can be set directly through a flag in the UE.

After the subroutine <NUM>, the UE goes through subroutine <NUM>. That is, the no result from block <NUM> passes to block <NUM>, which performs subroutine <NUM>. The yes result from block <NUM> passes to block <NUM>, which also performs subroutine <NUM>. The subroutine <NUM> is a bit more complex than subroutine <NUM>, as this subroutine aims to detect the location of the UE, i.e., whether if the UE is in the outer region <NUM> of the cell <NUM>, such as being on a cell edge <NUM>, or not.

For subroutine <NUM>, the UE gathers <MAT> values for multiple cells, and, as one would expect for a UE in the outer region <NUM> (e.g., on the cell edge <NUM>), these values should be closer to each other than if the UE were farther away from the outer region <NUM>/cell edge <NUM>. The <MAT> for multiple cells is compared by a threshold, e.g., cell_edge_measurements_tolerance, and the UE can decide whether the UE is in the outer region <NUM> (e.g., on the cell edge <NUM>) or not.

Consider the following example:
<MAT> where the right-hand side may have measurements in, e.g., dBm, and the left-hand side has a comparison value, e.g., in dBm. Note that the use of dBm is merely exemplary, and other units might be used.

If the above condition holds, the UE would return yes, otherwise the UE would return no.

In block <NUM>, if the UE determines it is not in the outer region <NUM> (e.g., on the cell edge <NUM>) (block <NUM> = no), then the UE determines the UE has low variation in block <NUM>. If the UE determines it is in the outer region <NUM> (e.g., on the cell edge <NUM>) for block <NUM> (block <NUM> = yes) or if the UE determines it is not in the outer region <NUM> (e.g., on the cell edge <NUM>) for block <NUM> (block <NUM> = no), the UE determines in block <NUM> that it has medium variation. If the UE determines it is in the outer region <NUM> (e.g., on the cell edge <NUM>) for block <NUM> (block <NUM> = yes), the UE determines in block <NUM> that it has high variation. Each of the three variations in <NUM>, <NUM>, and <NUM> are groups, and there could be more or fewer groups.

It is noted that another alternative rather than (or possibly in addition to) determining a location of the UE and whether the UE is in an outer region of a cell is to use received power (see block <NUM>) as an indicator of signal variation. The received power might be more indicative of the signal variation level (e.g., low received power (e.g., RSRP) means higher variation) and the received signal power is in a way related to location but not always.

In another embodiment, the UE can report its configuration and some additional parameters related to its signal reception. Thus, the variation of a UE can be decided by the base station. Also, the UE can detect its signal level variation and report this to the BS.

This section uses <FIG> as an exemplary embodiment. <FIG> is a flowchart for UEs decision for RRM measurement relaxation, in accordance with an exemplary embodiment. <FIG> illustrates the operation of exemplary methods, a result of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and/or interconnected means for performing functions in accordance with exemplary embodiments. <FIG> is performed by a UE <NUM>, e.g., under control of a control module <NUM>, at least in part.

With respect to the equations above, the UE compares the left-hand part that the UE measured, with the right-hand part. If the inequality mathematically holds for a period of time, e.g., of a predetermined time period T, then the UE declares the stationarity is detected.

As the parameters are used to detect different variations of the signal level, medium and high variation parameters can be different. It is expected that the medium variation will be smaller (e.g., in absolute value) than the high variation parameter. If a medium variation is used, stationary is less likely to be detected than if the high variation is used.

Srxlev represents, in an exemplary embodiment, the filtered outcome of recent measurements, i.e., layer <NUM> filtering. In one embodiment, the BS can communicate to the UE different timer parameters for different variation levels. Different timer parameters may depict the need to use different number of samples for filtering of measurements, i.e., layer <NUM> filtering. Also, different timer parameters may depict different sliding window for filtering, i.e., layer <NUM> filtering.

These timer parameters may be part of parameters configured for the UE, and the UE may use these to determine the estimate of the level of signal variance. For instance, first and second timer parameters may be configured (e.g., by the BS) for the UE. The UE may use the first timer parameter to determine the estimate of the level of signal variance as having the high signal variation. The UE may use the second timer parameter to determine the estimate of the level of signal variance as having the medium signal variation.

<NUM>) If the condition in step <NUM> is fulfilled (block <NUM> = yes, meaning meas. relaxation is suitable, such as the UE is stationary):.

<NUM>) Otherwise (block <NUM> = no), the UE <NUM> goes back to checking (block <NUM>) stationarity with each new measurement.

<NUM>) If the condition in step <NUM> is not fulfilled (block <NUM> = no, meaning the UE is not suitable for meas. relaxation, e.g., is not stationary):.

The description in <FIG> highlights identifying the UE for measurement relaxation, to check stationarity of the UE. While checking stationarity of the UE can lead to measurement relaxation, stationarity itself can be used even independently of measurement relaxation. For instance, the determination of the level of signal variation and the checking the corresponding condition(s) using the new parameters described above and herein can be used for stationarity detection rather than measurement relaxation. Stationarity can also be useful for many use cases other than measurement relaxation, such as adjusting the rate of tracking area update or RAN notification area update, and timing advance optimization, as some examples.

In another embodiment, a UE-specific signal variation correction parameter for each UE is transmitted through RRC signaling to the UE <NUM> from the BS <NUM>. This value is specific to a UE. This incurs extra overhead, as transmitting the parameter requires specific signaling to each UE. And the above-mentioned method, where the UEs are grouped in high and medium variation, is more resource efficient to utilize. Regardless, transmitting the parameter separately to each UE is a viable alternative.

The examples above consider mainly RRM measurement relaxation, where time between RRM measurements is extended from a current time to a longer time. It is, however, possible to modify the time between RRM measurements in a different way. For instance, the signal variation in <FIG> may change from when a UE performs the flow in <FIG> to another time when the UE performs the flow in <FIG>. The flow in <FIG> may also be modified, based on change in signal variation or the other factors in <FIG>. <FIG> illustrates the concept where time between RRM measurements may be modified by shortening or lengthening (or keeping the same) a current time between RRM measurements.

Turning to <FIG>, this is a flowchart for UEs decision for RRM measurement modification, in accordance with the claimed embodiment. <FIG> illustrates the operation of methods, a result of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and/or interconnected means for performing functions in accordance with embodiments. <FIG> is performed by a UE <NUM>, e.g., under control of a control module <NUM>, at least in part. The blocks in <FIG> mirror those in <FIG>, except for new blocks <NUM> and <NUM>, which correspond respectively to blocks <NUM> and <NUM>.

In block <NUM>, the UE identifies whether the UE should be identified for measurement modification, and one factor can be stationarity of the UE. If there is no measurement modification (block <NUM>= no), the flow proceeds to block <NUM>. If there is measurement modification (block <NUM>= yes), the flow proceeds to block <NUM>. In block <NUM>, the UE is identified for measurement modification and the RRM measurements are modified by increasing or decreasing the time between RRM measurements from a current time to an increased or decreased time, as the case may be. Flow proceeds to block <NUM>, which is described above.

While there are other ways to support implementing the exemplary embodiments, one option is to modify relaxedMeasurement configuration in SIB2. To support the exemplary embodiments, and in an exemplary embodiment, a stationarityEvaluation container could be used. The container may be contained in a relaxedmeasurement configuration, and include the s-SearchDeltaP-r16 and t-SearchDeltaP-r17 parameters. This relaxedMeasurement configuration also may contain the parameters for high/medium variation correction, e.g., stationary_UE_high_variation_correction and stationary_UE_medium_variation_correction. This is only one example of how these might be implemented, and other examples are possible.

This section relates one possible example. This example uses <FIG>, which is a diagram of a message sequence chart for an exemplary embodiment. <FIG> also illustrates the operation of exemplary methods, a result of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and/or interconnected means for performing functions in accordance with exemplary embodiments. <FIG> is performed by a UE <NUM>, e.g., under control of a control module <NUM>, at least in part, and by a BS <NUM>, e.g., under control of a control module <NUM>, at least in part.

In <FIG>, the UE <NUM> connects to a new cell, e.g., via cell selection signaling <NUM>. The UE sets Srxlev. Ref to Srxlev in block <NUM>.

The UE acquires SIB2 (from signaling <NUM>) and detects the relaxedMeasurement is set in SIB2. It also detects that the optional parameter stationarityEvaluation is available. The s-SearchThresholdP is also detected. Further, the UE <NUM> extracts the stationarity_UE_high/medium_variation_correction parameters.

The UE starts the RRM measurements in operation <NUM>. Assume the UE in this example is an omni-antenna UE having high measurement accuracy and the UE is in the outer region <NUM> (e.g., or close to the cell edge <NUM>). The UE detects (block <NUM>) that the UE is in the outer region <NUM> (e.g., or close to the cell edge <NUM>), using logic given in <NUM>, described above.

As the UE decides it is a high variation UE, the UE <NUM> decides to use the stationary_UE_high_variation_correction parameter to detect stationarity. The UE in block <NUM> measures Srxlev periodically.

The UE considers Srxlev. Ref - Srxlev < SSearchDeltaP + stationary_UE_high_variation_correction, and the UE observes that the inequality holds for a period of T-searchDeltaP. The UE therefore detects it is stationary in block <NUM>.

The UE optionally reports that it is stationary in RNA update <NUM>, with a stationarity declaration. The UE extends its RRM measurement timer (see reference <NUM>), in this example to be <NUM> hours. That is, each <NUM>-hour period, the UE wakes up and performs the RRM measurements and determines if the previous conditions still hold. Although a <NUM>-hour period is used, other periods shorter or longer than that may also be used.

Turning to <FIG>, this figure is a flowchart performed by a UE for measurement modification, in accordance with an exemplary embodiment. <FIG> illustrates the operation of exemplary methods, a result of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and/or interconnected means for performing functions in accordance with exemplary embodiments. <FIG> is performed by a UE <NUM>, e.g., under control of a control module <NUM>, at least in part.

In block <NUM>, the UE <NUM> receives one or more parameters to be used to identify the user equipment for measurement modification. The UE <NUM> is connected to a base station <NUM> in a wireless network <NUM>. In block <NUM>, the UE <NUM> determines an estimate of a level of signal variation for signals received at the UE <NUM>. The UE <NUM>, in block <NUM>, identifies, using at least the one or more parameters, the user equipment for measurement modification based at least on the estimate of the level of signal variation. The UE <NUM> in block <NUM> modifies, by the user equipment, a time between measurements for radio resource management from a current time to a different time in response to the user equipment being identified for measurement modification.

It is noted that the modification in time between measurements may be similar to the previously described measurement relaxation. As described above, measurement relaxation allows the UE to perform fewer measurements over time (e.g., than currently performed under a current configuration), such as the UE will perform measurements less frequently, the UE is allowed to skip some measurements, the UE is allowed to determine when to perform measurements, and/or the UE will measure fewer cells or frequencies. In case the time between measurements is decreased, the UE can perform more measurements over time (e.g., than currently performed under a current configuration), such as the UE will perform measurements more frequently, the UE is not allowed to skip some measurements, the UE is not allowed to determine when to perform measurements, and/or the UE will measure more cells or frequencies.

<FIG> is a flowchart performed by a base station for measurement modification, in accordance with an exemplary embodiment. <FIG> illustrates the operation of exemplary methods, a result of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and/or interconnected means for performing functions in accordance with exemplary embodiments. <FIG> is performed by a base station <NUM>, e.g., under control of a control module <NUM>, at least in part.

In block <NUM>, the BS <NUM> determines one or more parameters to be used by a UE <NUM> in order to identify the user equipment for measurement modification. The BS <NUM> in block <NUM> signals the one or more parameters to the UE <NUM>.

Without in any way limiting the scope, interpretation, or application of the claims appearing below, a technical effect and advantage of one or more of the example embodiments disclosed herein is stationarity of heterogenous devices can be detected. Another technical effect and advantage of one or more of the example embodiments disclosed herein is that stationary UEs can decrease the signaling stemming from energy heavy mobility signaling procedures, thereby saving energy.

Embodiments herein may be implemented in software (executed by one or more processors), hardware (e.g., an application specific integrated circuit), or a combination of software and hardware. In an example embodiment, the software (e.g., application logic, an instruction set) is maintained on any one of various conventional computer-readable media. In the context of this document, a "computer-readable medium" may be any media or means that can contain, store, communicate, propagate or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer, with one example of a computer described and depicted, e.g., in <FIG>. A computer-readable medium may comprise a computer-readable storage medium (e.g., memories <NUM>, <NUM>, <NUM> or other device) that may be any media or means that can contain, store, and/or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer. A computer-readable storage medium does not comprise propagating signals.

It is also noted herein that while the above describes example embodiments of the invention, these descriptions should not be viewed in a limiting sense. Rather, there are several variations and modifications which may be made without departing from the scope of the present invention as defined in the appended claims.

Claim 1:
A method, comprising:
receiving, by a user equipment (<NUM>) connected to a base station (<NUM>) in a wireless network, one or more parameters to be used by the user equipment to identify the user equipment (<NUM>) for measurement modification;
determining, by the user equipment, an estimate of a level of signal variation for signals received at the user equipment (<NUM>);
identifying, using at least the one or more parameters, the user equipment (<NUM>) for measurement modification based at least on the estimate of the level of signal variation, wherein identifying the user equipment (<NUM>) for measurement modification comprises determining that the user equipment (<NUM>) is stationary and identifying the user equipment (<NUM>) as suitable for measurement modification because the user equipment (<NUM>) is stationary; and
modifying, by the user equipment (<NUM>), a time between measurements for radio resource management from a current time to a different time in response to the user equipment (<NUM>) being identified for measurement modification.