Method and device of measurement report enhancement for aerial UE

A method of measurement report enhancement for aerial UE. A method of measurement report enhancement, the method comprising: receiving a measurement report configuration with a new measurement triggering condition and corresponding threshold from eNB; performing measurements of a cells according to the new measurement triggering condition; evaluating if a new triggering condition is satisfied according to the threshold based on the measurement result of cells; and reporting the measurement report to the eNB when the new triggering condition is satisfied.

FIELD

The subject matter disclosed herein generally relates to wireless communications and more particularly relates to a method and device for measurement report enhancement for aerial UE.

BACKGROUND

The following abbreviations are defined herewith, at least some of which are referred to in the following description: Third Generation Partnership Project (“3GPP”), Downlink (“DL”), Evolved Node B (“eNB”), Long Term Evolution (“LTE”), Radio Resource Control (“RRC”), Access Network (“AN”), Radio Access Network (“RAN”), User Entity/Equipment (Mobile Terminal) (“UE”), and Uplink (“UL”).

There has been increasing interest in covering aerial vehicles such as drones with cellular networks. The use cases of commercial drones are growing very rapidly and include: package delivery, search-and-rescue, monitoring of critical infrastructure, wildlife conservation, flying cameras, and surveillance. All of these use cases could undergo rapid growth, and more will emerge in coming years. Many of these emerging use cases could benefit from connecting drones to the cellular network as a UE. LTE is well positioned to serve aerial vehicles such as drones. In fact, there have been an increasing number of field-trials involving the use of LTE networks to provide connectivity to drones. It is predicted that a rapid and vast growth in the drone industry will bring new promising business opportunities for LTE operators. To address this growing market demand, a new study item (SI) called “Study on Enhanced LTE Support for Aerial Vehicles” has been approved by 3GPP TSG RAN #75 [1]. The following enhancements were proposed:

Interference mitigation solutions for improving system-level performance in both UL and DL;

Solutions to detect whether a UL signal from an airborne UE increases interference in multiple neighboring cells and whether an airborne UE incurs interference from multiple cells;

Identification of an airborne UE that does not have proper certification for connecting to the cellular network while airborne;

Handover: Identify if enhancements of cell selection and handover efficiency, as well as robustness in handover signaling, can be achieved; and

Positioning: If time allows a 2nd priority, assess the achievable accuracy with existing positioning techniques and identify potential enhancements.

REFERENCES

[7]. R2-1708973, “Consideration for Interference Detection and Measurement Enhancement for Drone UE”, Lenovo, Motorola Mobility.

The above references are identified by the RAN group from the radio aspect. However, there exist other problematic issues which also need to be solved.

According to the RAN2 #98 online meeting agreement, it was agreed, in the interests of interference detection, to study the enhancement of measurement report mechanisms in order to address the issue of an increased number of strong neighboring cells.

During the RAN2 #99 meeting, several companies proposed solutions for measurement enhancement for the purpose of interference detection, which is summarized as the following:

1). Multi-cell trigger mechanism: when multiple-cell measurement results all fulfill the configured triggering threshold, the measurement report is triggered.

2). Multi-cell trigger mechanism with a timer for max measurement report delay: when multiple cell measurement results all fulfill the configured triggering threshold, the measurement report is triggered. If the measured cells did not fulfill the indicated multi-cell number, then after the timer is expired, the measurement is still triggered to be reported.

3). Specific TTT value: Use aerial specific TTT value with enlarged value compared with terrestrial UEs. And such enlarged TTT value can be used to await more measurement results, so that multiple measurement results can be reported in one measurement report.

However, all of the above mechanisms have disadvantages, for which the key problem may include the following: 1) the multi-cell trigger is not directly related to the total interference that the aerial UE suffers; 2) extra delays are introduced for the measurement report; and/or 3) additional delays will be always introduced, and this is not even considering the total interference from neighboring cells.

BRIEF SUMMARY

Methods and devices for measurement report enhancement for aerial UE are disclosed. A method of measurement report enhancement for aerial UE is disclosed.

In one embodiment, a method of measurement report enhancement, the method comprising: receiving a measurement report configuration with a corresponding threshold and condition configuration and possible new measurement triggering event from eNB; performing measurements of cells according to the new measurement triggering event or new trigger condition; evaluating whether a new triggering condition or the new measurement triggering event is satisfied with the threshold based on the measurement result of cells; and reporting the measurement report to the eNB upon the new triggering condition or new trigger event to be satisfied.

In one embodiment, wherein the measurement report configuration includes: a new measurement event name; a first threshold for determining whether the sum of measurement results of neighboring cells is satisfied; and/or a second threshold for determining whether each neighboring cell result is satisfied, and the number of measured neighboring cells results.

In one embodiment, the new triggering condition includes an (entering) condition 1, the (entering) condition 1 and a (entering) condition 2, or the combination of the (entering) condition 1 and the (entering) condition 2.

In one embodiment, wherein the (entering) condition 1 is that the sum of measurement results of neighboring cells is larger than the first threshold, based on the following formula:
Offset1×10 log(Σi=1m(Offset2i×Pni+Offset3i))+Offset4>ThreshRSRPSum,

Where Pniis the measurement results for ith measured neighboring cell, m is the total number of measured neighboring cells results, or m is the number of cells that fulfill the (entering) condition 2, or m represents the first m measurement results of neighboring cells in the measurement results list, ordered such that the best cell is listed first, and the value of m is configured by the higher layer, ThreshRSRPSum is the threshold for the sum of measurement results of measured neighboring cells, and is expressed in dBm, Offset1is a scaling factor which is configured by eNB for this event, Offset2iis a scaling factor which is configured by eNB for each measured neighboring cell i, Offset3iis an offset value configured by eNB for each measured neighboring cell, and Offset4is an offset value configured by eNB for this event. Pniand Offset3iare expressed in mW in case of RSRP; Offset4and ThreshRSRPSum are expressed in dBm in case of RSRP, or in dB in case of RSRQ and RS-SINR.

In one embodiment, the (entering) condition 2 is that the measurement result of the neighboring cell is better than a threshold based on the following formula:
Mn+Ofn+Ocn−Hys>Thresh

Where the variables in the formula are defined as follows: Mn is the measurement result of the neighboring cell, not taking into account any offsets; Ofn is the frequency specific offset of the frequency of the neighboring cell; Ocn is the cell specific offset of the neighboring cell; Hys is the hysteresis parameter for this event; Thresh is the threshold parameter for this event; Mn and Thresh are expressed in dBm in case of RSRP, or in dB in case of RSRQ and RS-SINR; Ofn, Ocn, Hys are expressed in dB.

A UE for measurement report enhancement, the UE comprising: a transceiver; a processor is configured to control the transceiver to: receiving a measurement report configuration with corresponding threshold and condition configuration and possible new measurement triggering event from eNB; performing measurements of a cells according to the new measurement triggering event or new trigger condition; evaluating whether a new triggering condition for the new measurement triggering event is satisfied with the threshold based on the measurement result of cells; and reporting the measurement report to the eNB when the new triggering condition or new trigger event is satisfied.

DETAILED DESCRIPTION

Any combination of one or more computer readable medium may be utilized. The computer readable medium may be a computer readable storage medium. The computer readable storage medium may be a storage device storing the code. The storage device may be, for example, but need not necessarily be, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

A non-exhaustive list of more specific examples of the storage device would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, random access memory (“RAM”), read-only memory (“ROM”), an erasable programmable read-only memory (“EPROM” or Flash memory), a portable compact disc read-only memory (“CD-ROM”), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device.

The code may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the code executed on the computer or other programmable apparatus provides processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

FIG. 1depicts an embodiment of a wireless communication system100. In one embodiment, the wireless communication system100includes mobile units105, and base units110. Even though a specific number of mobile units105and base units110are depicted inFIG. 1, one skilled in the art will recognize that any number of mobile units105and base units110may be included in the wireless communication system100.

In one embodiment, the mobile units105may include aerial vehicles such as drones or the like. Examples of use cases of drones include package delivery, search-and-rescue, monitoring of critical infrastructure, wildlife conservation, flying cameras, and surveillance. The mobile units105may be referred to as remote units, subscriber units, mobiles, mobile stations, users, terminals, mobile terminals, UEs, subscriber stations, user terminals, a device, or by other terminology used in the art. The mobile units105may communicate wirelessly with one or more of the base units110.

The base units110may be distributed over a geographic region. In certain embodiments, a base unit110may also be referred to as an access point, an access terminal, a base, a base station, a Node-B, an eNB, a gNB, a Home Node-B, a relay node, a device, or by any other terminology used in the art.

In one implementation, the wireless communication system100is compliant with the LTE of the 3GPP protocol. More generally, however, the wireless communication system100may implement some other open or proprietary communication protocol. The present disclosure is not intended to be limited to the implementation of any particular wireless communication system architecture or protocol.

The base units110may serve a number of mobile units105within a serving area, for example, a cell or a cell sector via a wireless communication link. The base units110may communicate directly with one or more of the remote units105via communication signals. Generally, the base units110transmit downlink (“DL”) communication signals to serve the remote units105in the time, frequency, and/or spatial domain.

FIG. 2is a schematic diagram illustrating an existing measurement procedure.

FIG. 2depicts a method for an existing measurement procedure. As depicted inFIG. 2, the method for an existing measurement procedure includes steps 1-4:

Step 1 is the measurement configuration step, whereby eNB configures a measurement report with trigger conditions, and other measurement related configuration;

Step 2 is the UE performance measurement step, whereby UE performs the cell measurements based on the measurement configuration;

Step 3 is the measurement report triggering step, whereby the UE evaluates trigger conditions according to the cell measurements results, and when the cell measurements results satisfy the trigger conditions, step 3 proceeds to step 4; and

Step 4 is the measurement reporting step, whereby the UE reports measurement reports for cells that fulfill the trigger conditions.

FIG. 3is a schematic chart diagram illustrating a new measurement procedure for measurement report enhancement.FIG. 4is a schematic flow chart diagram illustrating a new measurement procedure for measurement report enhancement.

FIGS. 3 and 4depict a method for a new measurement procedure for measurement report enhancement. We will describe the new measurement procedure based onFIGS. 3 and 4.

As depicted inFIG. 3, the method for a new measurement procedure for measurement report enhancement includes steps 1-5.

Step 1 is the measurement configuration step, whereby eNB configures a measurement report with a corresponding threshold and condition configuration and new measurement triggering event;

Step 2 is the UE performance measurement step, whereby UE performs the cell measurements based on the new trigger measurement event or new trigger condition;

Step 3 is the measurement report triggering step, whereby the UE evaluates the new trigger condition or new trigger event according to the cell measurements results; and

Step 4 is measurement reporting, whereby the UE reports measurement results for cells that fulfill the configured new trigger condition or new trigger event.

Preferably, the method for new measurement procedure for measurement report enhancement further includes step 5. In step 5, a prohibit timer is started to prevent the following measurement report. After the prohibit timer is expired, the trigger measurement result can be reported again.

As depicted inFIG. 4, the method for the new measurement procedure for measurement report enhancement includes steps 1-4 and/or 5.

In step 401, UE receives a measurement report configuration with the corresponding threshold and condition configuration and the new measurement triggering event from eNB;

In step 402, UE performs measurements of a cells;

In step 403, UE evaluates whether a new triggering condition or new trigger event is satisfied based on the new measurement result of cells; and

In step 404, UE reports the measurement report to the eNB when the new triggering condition or new trigger event is satisfied.

Preferably, inFIG. 4, the method further includes running a prohibit timer, whereby the prohibit timer is started/restarted after the measurement report is reported, and after the prohibit timer is expires, the measurement results can be reported if triggered.

FIG. 5is a schematic flow chart diagram illustrating one embodiment of a method for measurement report enhancement. As depicted inFIG. 5, the method for the new measurement procedure for the measurement report enhancement includes:

In measurement configuration for report configuration, a new measurement triggering event or new trigger condition is configured, and the report configuration includes one or more elements in the following:

ii. New (event) threshold 1 for determining whether a sum of measurement results of neighboring cells, e.g. ThreshRSRPSum is satisfied;

iii. New (event) threshold 2 for determining whether each neighboring cell result, e.g. ThresholdEUTRA, is satisfied;

iv. The number of measured neighboring cell results used for determining whether the triggering condition is satisfied in the new measurement triggering event or new trigger condition, e.g. m; and

v. Preferably, the method for the first embodiment further includes the prohibit timer, which is used to prevent frequent measurement reporting for interference detection purposes.

2. Step 502 is the UE performance measurement step, UE performs the cell measurements based on the new trigger measurement event or new trigger condition.

A new measurement triggering event or new trigger condition can be defined, that the UE shall consider the (entering) conditions for this new measurement triggering event to be satisfied when (entering) condition 1 is fulfilled, both (entering) condition 1 and 2 are fulfilled, or the combination of the (entering) conditions 1 and 2.

In step 503, (entering) condition 1: the sum of measurement results of neighboring cells larger than a configured threshold based on the following formula;
Offset1×10 log(Σi=1m(Offset2i×Pni+Offset3i))+Offset4>ThreshRSRPSum

The variables in the formula are defined as follows: Pniis the measurement results for ith measured neighboring cell, and such measurement result can be RSRP and expressed in mW; where m is the total number of measured neighboring cells results, or m is the number of neighboring cells whose results fulfill the Entering condition 2, or m represents the first m measurement results of neighboring cells in the measurement results list, which is ordered such that the best cell is listed first, and the value of m is configured by the higher layer; ThreshRSRPSum is the higher layer configured threshold value, which is used to determine whether the sum of measurement results of measured neighboring cells is still tolerant. ThreshRSRPSum is expressed in dBm; Offset1is a scaling factor which is configured by eNB for this event. The range of Offset1can be e.g. [0,1] or Offset1belongs to {0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0}. Offset1can exist or not exist in the above equation; Offset2iis a scaling factor which is configured by eNB for each measured neighboring cell i. The range of Offset2ican be e.g. [0,1] or Offset2ibelongs to {0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0}. Offset2ican exist or not exist in the above equation; Offset3iis an offset value configured by eNB for each measured neighboring cell i. Offset3ican be the offset of frequency specific offset of the frequency of the neighboring cell i, or the cell specific offset of the neighboring cell i, or the hysteresis parameter for this event. Offset3ican exist or not exist in the above equation; Offset4is an offset value configured by eNB for this event. Offset4can be the offset of frequency specific offset of the measuring frequency, or the hysteresis parameter for this event. Offset4can exist or not exist in the above equation. Pniand Offset3iare expressed in mW in case of RSRP; Offset4and ThreshRSRPSum are expressed in dBm in case of RSRP, or in dB in case of RSRQ and RS-SINR.

Further, the UE shall consider the leaving condition for this new measurement triggering event to be satisfied when leaving condition 1 is fulfilled;

Leaving condition 1: the sum of measurement results of neighboring cells is smaller than a higher layer configured threshold
Offset1×10 log(Σi=1m(Offset2i×Pni+Offset3i))+Offset4<ThreshRSRPSum

In step 504, the UE shall consider the entering condition 2 which is defined as follows;

Entering condition 2: neighboring cell results are better than a threshold based on the following formula:
Mn+Ofn+Ocn−Hys>Thresh

The variables in the above formula are defined as follows: Mn is the measurement result of the neighboring cell, not taking into account any offsets; Ofn is the frequency specific offset of the frequency of the neighboring cell (i.e. offsetFreq as defined within measObjectEUTRA, corresponding to the frequency of the neighboring cell); Ocn is the cell specific offset of the neighboring cell (i.e. cellIndividualOffset as defined within measObjectEUTRA corresponding to the frequency of the neighboring cell), and set to zero if not configured for the neighboring cell; Hys is the hysteresis parameter for this event (i.e. hysteresis as defined within reportConfigEUTRA for this event); Thresh is the threshold parameter for this event (i.e. a4-Threshold as defined within reportConfigEUTRA for this event); Mn is expressed in dBm in case of RSRP, or in dB in case of RSRQ and RS-SINR; Ofn, Ocn, Hys are expressed in dB; and Thresh is expressed in the same unit as Mn.

Further, in step 505, the entering condition 1 and entering condition 2 can be combined as one condition, which is as follows. The description of each parameter is the same as in steps 503 and 504:

Step 506 is measurement reporting, the UE reports measurement results for cells that satisfied the above (trigger) condition, based on the configured new trigger measurement event or new trigger condition.

Preferably, the method for the first embodiment further includes step 507. In step 507, a prohibit timer is started to prevent the following measurement report. After the prohibit timer is expired, the trigger measurement result can be reported again.

The prohibit timer is configured by a higher layer, and is started/restarted after the measurement result is reported. During the running of the prohibit timer, all measurement results that used interference detection for aerial UE will not be reported even if the report is triggered, and the triggered measurement report will be stored until the prohibit timer expires, or, if the triggered measurement report is abandoned while the prohibit timer is running, and after prohibit timer is expires, the measurement results can be reported if triggered.

FIG. 6is a schematic flow chart diagram illustrating the second embodiment of a method for measurement report enhancement. As depicted inFIG. 6, the method for the new measurement procedure for measurement report enhancement includes:

Step 601: Measurement configuration

In the measurement configuration for report configuration, a new measurement triggering event or a new trigger condition is configured, and the report configuration includes one or more elements in the following:

ii. New (event) threshold 1 for determining whether the RSSI of UE fulfils the triggering condition or trigger event, that is, the threshold configured by higher layer.

iii. New (event) threshold 2 for determining whether each neighboring cell result, e.g. ThresholdEUTRA, is satisfied;

iv. Preferably, the method for the second embodiment further includes the prohibit timer, which is used to prevent frequent measurement reporting for interference detection purposes.

2. Step 602 is the UE performance measurement step, where the UE performs the cell measurements based on the new trigger measurement event or new trigger condition.

A new measurement triggering event or new trigger condition is defined, such that the UE shall consider the (entering) condition for this new measurement triggering event or new trigger condition to be satisfied when (entering) condition 1 is fulfilled, or when both (entering) condition 1 and 2 are fulfilled.

In step 603, (entering) condition 1: the RSSI is larger than a threshold that configured by higher layer based on the following formula:
RSSI>Thresh

The variables in the formula are defined as follows: RSSI is the measured E-UTRA Received Signal Strength Indicator (RSSI) by the UE, Thresh is the higher layer configured threshold value, which is used to determine whether the RSSI fulfils the condition.

Further, the UE shall consider the leaving condition for this new measurement triggering event to be satisfied when the leaving condition is fulfilled.

Leaving condition: the RSSI is smaller than a threshold configured by the higher layer based on the following formula:
RSSI>Thresh

In step 604, the UE shall consider the entering condition 2 which is defined as follows.

The entering condition 2: neighboring cell results are better than a threshold based on the following formula:
Mn+Ofn+Ocn−Hys>Thresh

The variables in the formula are defined as follows: Mn is the measurement result of the neighboring cell, not taking into account any offsets; Ofn is the frequency specific offset of the frequency of the neighboring cell (i.e. offsetFreq as defined within measObjectEUTRA and corresponding to the frequency of the neighboring cell); Ocn is the cell specific offsetting of the neighboring cell (i.e. celllndividualOffset as defined within measObjectEUTRA and corresponding to the frequency of the neighboring cell), and set to zero if not configured for the neighboring cell; Hys is the hysteresis parameter for this event (i.e. hysteresis as defined within reportConfigEUTRA for this event); Thresh is the threshold parameter for this event (i.e. a4-Threshold as defined within reportConfigEUTRA for this event); Mn is expressed in dBm in case of RSRP, or in dB in case of RSRQ and RS-SINR; Ofn, Ocn, and Hys are expressed in dB; and Thresh is expressed in the same unit as Mn.

Step 605 is measurement reporting, the UE reports measurement results for cells that satisfied the above trigger condition based on the configured new trigger measurement event or new trigger condition.

Preferably, the method for the first embodiment further includes step 606. In step 606, a running prohibit timer is started to prevent following the measurement report. After the running prohibit timer has expired, the trigger measurement result can be reported again.

The prohibit timer is configured by the higher layer; and

The prohibit timer is configured by the higher layer, the prohibit timer is started/restarted after the measurement result is reported. During the running of the prohibit timer, all measurement results used for interference detection for aerial UE will not be reported even if the report is triggered, and the triggered measurement report will be stored until the prohibit timer expires, or, the triggered measurement report is abandoned while the prohibit timer is still running, and after prohibit timer expires, the measurement results can be reported if triggered.

FIG. 7illustrates a block diagram of a wireless communication apparatus according to the first and the second embodiments.

Referring toFIG. 7, a wireless communication system includes a eNB and multiple UEs positioned within an area of the eNB.

The eNB includes a processor, a memory, and a transceiver. The processor implements a function, a process, and/or a method which are proposed inFIGS. 2 to 6above. Layers of a radio interface protocol may be implemented by the processor. The memory is connected with the processor to store various pieces of information for driving the processor. The transceiver is connected with the processor to transmit and/or receive a radio signal.

The UE includes a processor, a memory, and a transceiver. The processor implements a function, a process, and/or a method which are proposed inFIGS. 2 to 6above. Layers of a radio interface protocol may be implemented by the processor. The memory is connected with the processor to store various pieces of information for driving the processor. The transceiver is connected with the processor to transmit and/or receive a radio signal.

The memories may be positioned inside or outside the processors and connected with the processors by various well-known means. Further, the eNB and/or the UE may have a single antenna or multiple antennas.

In the embodiments described above, the components and the features of the embodiments are combined in a predetermined form. Each component or feature should be considered as an option unless otherwise expressly stated. Each component or feature may be implemented not to be associated with other components or features. Further, the embodiment may be configured by associating some components and/or features. The order of the operations described in the embodiments may be changed. Some components or features of any embodiment may be included in another embodiment or replaced with the component and the feature corresponding to another embodiment. It is apparent that the claims that are not expressly cited in the claims are combined to form an embodiment or be included in a new claim.

The embodiments may be implemented by hardware, firmware, software, or combinations thereof. In the case of implementation by hardware, according to hardware implementation, the exemplary embodiment described herein may be implemented by using one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, and the like.

In the case of implementation by firmware or software, the embodiment may be implemented in the form of a module, a procedure, a function, and the like to perform the functions or operations described above. A software code may be stored in the memory and executed by the processor. The memory may be positioned inside or outside the processor and may transmit and receive data to/from the processor by various means.