Enhanced method for preparing conditional handover to avoid preemption

Abstract

The invention relates to an enhanced method for preparing conditional handover to avoid preemption. According to some embodiments, a method may include transmitting, by a source network entity, at least one handover preparation request to a target network entity, the at least one handover preparation request including at least one extension indication. The method may also include receiving, by the source network entity, at least one handover request response from the target network entity in response to the at least one handover preparation request. The method may also include transmitting, by the source network entity, at least one handover command acknowledgement to the at least one user equipment based on the at least one handover request response.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is a divisional application of an invention patent application with an application date of July 26, 2019, application number 201980062490.9, and invention name “Enhanced method for preparing conditional switching to avoid preemption”.

[0003] This application claims the benefit of U.S. Provisional Application No. 62 / 742,001, filed on October 5, 2018. The entire contents of the above-referenced applications are incorporated by reference. Technical Field

[0004] Certain embodiments may relate to wireless communication systems.For example, some embodiments may relate to conditional handover. Background Art

[0005] Conditional handover can play a role in mobility improvement in some wireless communication systems. Conditional handover can be similar to traditional handover techniques, where a configured event triggers the user equipment to send a measurement report. The source network entity can use the measurement report to notify the target network entity of the handover, and then send the handover command to the user equipment.

[0006] With respect to conventional handover, the user equipment may immediately access the target cell to complete the handover process. In contrast, with respect to conditional handover, the user equipment will only access the target entity after the additional conditional handover execution conditions expire. The conditions for such handovers are usually configured by the source network entity as part of the handover command. Conditional handover allows the handover command to be transmitted earlier while the user equipment is still associated with the source network entity, without risking access and stability with the target network entity.

[0007] Conditional switching can be associated with uncertainty. With conventional switching, a target network entity can reserve resources for a user equipment within a limited time because the user equipment will appear soon. Such resources can be random access channel (RACH) resources, as well as other resources for processing data and control bearers, such as control channels and physical resource blocks. In contrast, resources using conditional switching may need to be reserved for a longer period of time. In particular, an uncertain amount of time may be required before the condition triggers the final execution of the conditional switching, so that unnecessary resources are unnecessarily reserved for too long. In addition, the earlier a target network entity receives a switching notification, the more likely it is that the target network entity is the wrong target network entity. As a result, the conditional switching may be cancelled, never executed, or executed for different targets, resulting in a waste of network resources. Therefore, it is desirable to increase the radio resources used for data by reducing resource reservations and to improve the preparation part of conditional switching. Summary of the invention

[0008] According to some embodiments, a method may include: transmitting, by a source network entity, at least one handover preparation request including at least one extended indication to a target network entity. The method may also include: receiving, by the source network entity, at least one handover request response from the target network entity in response to the at least one handover preparation request. The method may also include: transmitting, by the source network entity, at least one handover command confirmation to at least one user equipment based on the at least one handover request response.

[0009] According to some embodiments, an apparatus may include: means for transmitting at least one handover preparation request including at least one extended indication to a target network entity. The apparatus may also include: means for receiving at least one handover request response from the target network entity in response to the at least one handover preparation request. The apparatus may also include: means for transmitting at least one handover command confirmation to at least one user equipment based on the at least one handover request response.

[0010] According to some embodiments, an apparatus may include at least one processor and at least one memory including computer program code. The at least one memory and the computer program code may be configured to, together with the at least one processor, cause the apparatus to at least: transmit at least one handover preparation request including at least one extended indication to a target network entity. The at least one memory and the computer program code may also be configured to, together with the at least one processor, cause the apparatus to at least: receive at least one handover request response from the target network entity in response to the at least one handover preparation request. The at least one memory and the computer program code may also be configured to, together with the at least one processor, cause the apparatus to at least: transmit at least one handover command confirmation to at least one user equipment based on the at least one handover request response.

[0011] According to some embodiments, a non-transitory computer readable medium may be encoded with instructions that, when executed in hardware, may perform a method. The method may include: transmitting at least one handover preparation request including at least one extended indication to a target network entity. The method may also include: receiving at least one handover request response from the target network entity in response to the at least one handover preparation request. The method may also include: transmitting at least one handover command confirmation to at least one user equipment based on the at least one handover request response.

[0012] According to some embodiments, an apparatus may include circuitry configured to transmit at least one handover preparation request including at least one extended indication to a target network entity. The circuitry may also be configured to receive at least one handover request response from the target network entity in response to the at least one handover preparation request. The circuitry may also be configured to transmit at least one handover command confirmation to at least one user equipment based on the at least one handover request response.

[0013] According to some embodiments, a computer program product may perform a method. The method may include: transmitting at least one handover preparation request including at least one extended indication to a target network entity. The method may also include: receiving at least one handover request response from the target network entity in response to the at least one handover preparation request. The method may also include: transmitting at least one handover command confirmation to at least one user equipment based on the at least one handover request response.

[0014] According to some embodiments, a method may include: receiving, by a target network entity, at least one handover preparation request including at least one extended indication from a source network entity. The method may also include: transmitting, by the target network entity, at least one handover request response to the source network entity based on the at least one handover preparation request. The method may also include: generating, by the target network entity, at least one resource reservation.

[0015] According to some embodiments, an apparatus may include means for receiving at least one handover preparation request including at least one extended indication from a source network entity. The apparatus may also include means for transmitting at least one handover request response to the source network entity based on the at least one handover preparation request. The apparatus may also include means for generating at least one resource reservation.

[0016] According to some embodiments, an apparatus may include at least one processor and at least one memory including computer program code. The at least one memory and the computer program code may be configured to, together with the at least one processor, cause the apparatus to at least: receive at least one handover preparation request including at least one extended indication from a source network entity. The at least one memory and the computer program code may also be configured to, together with the at least one processor, cause the device to at least: transmit at least one handover request response to the source network entity based on the at least one handover preparation request. The at least one memory and the computer program code may also be configured to, together with the at least one processor, cause the apparatus to at least generate at least one resource reservation.

[0017] According to some embodiments, a non-transitory computer readable medium may be encoded with instructions that, when executed in hardware, may perform a method. The method may include: receiving at least one handover preparation request including at least one extended indication from a source network entity. The method may also include: transmitting at least one handover request response to the source network entity based on the at least one handover preparation request. The method may also include: generating at least one resource reservation.

[0018] According to some embodiments, an apparatus may include: a circuit system configured to receive at least one handover preparation request including at least one extended indication from a source network entity. The circuit system may also be configured to: transmit at least one handover request response to the source network entity based on the at least one handover preparation request. The circuit system may also be configured to: generate at least one resource reservation.

[0019] According to some embodiments, a computer program product may perform a method. The method may include: receiving at least one handover preparation request including at least one extended indication from a source network entity. The method may also include: transmitting at least one handover request response to the source network entity based on the at least one handover preparation request. The method may also include: generating at least one resource reservation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] For a proper understanding of the present disclosure, reference should be made to the accompanying drawings, in which:

[0021] Figure 1 A signaling diagram according to certain embodiments is illustrated.

[0022] Figure 2 Another signaling diagram in accordance with certain embodiments is illustrated.

[0023] Figure 3 An example of a method of a target network entity according to some embodiments is illustrated.

[0024] Figure 4 An example of a method performed by a user equipment according to some embodiments is illustrated.

[0025] Figure 5 An example of a method performed by a source network entity according to certain embodiments is illustrated.

[0026] Figure 6 An example of a system according to some embodiments is illustrated. DETAILED DESCRIPTION

[0027] Certain embodiments described herein can help manage conditional switching. The example embodiments described herein can have various benefits and / or advantages. For example, some embodiments can increase the resources used for data by improving the preparation phase of conditional switching. Certain embodiments described herein can also activate and / or deactivate conditional switching features with finer granularity, such as temporarily, per user equipment, per bearer, and / or without clear network entity configuration update instructions. Therefore, certain embodiments specifically directly point to the improvement of computer-related technologies by saving network resources and reducing the consumption of network entities and / or user equipment located in the network.

[0028] Discussed herein are improvements to conditional handover. For example, when conditional handover is rejected, the source network entity may no longer initiate additional conditional handovers to the target network entity for a particular user equipment, while still allowing traditional handovers. Alternatively, the source network entity may indicate that as long as the bearer configuration does not change, additional conditional handovers may not be initiated for the user equipment, while still allowing traditional handovers. As another example, if the user equipment changes from a high bit rate service to a low bit rate service, such as when changing from web browsing to Voice over Internet Protocol (VoIP), then mobile robustness may be more important, where the drawbacks of preemption are reduced, resulting in the temporary deactivation of conditional handovers.

[0029] As further discussed herein, conditional handovers may be rejected and the source network entity may no longer use subsequent network entity configuration updates to initiate other conditional handovers to the target network entity for any user equipment in the associated cell. In addition, conditional handover deactivation may be temporarily restricted, such as based on the target network entity providing a timer value, allowing the source network entity to resume conditional handover when the timer expires. Additionally, the target cell may also specify a conditional deactivation on the current conditional handover configuration in the source cell. For example, it may use a HO PREPARATION FAILURE message to implicitly request the source entity to relax conditional handover parameters, allowing the source network entity to initiate other handovers when the conditional handover parameters are relaxed.

[0030] Figure 1 An example of a signaling diagram according to some embodiments is illustrated. In particular, Figure 1 The conditional handover preparation and conditional handover execution are shown. The user equipment (UE) 110 may be similar to Figure 6 Additionally, the source network entity (NE) 120 and / or the target NE 130 may be similar to Figure 6 Although only a single UE, source NE and target NE are illustrated, the communication network may contain one or more of each of these entities.

[0031] In step 101, the source NE 120 may transmit at least one measurement control indication to the UE 110. In step 103, the UE 110 may generate at least one conditional handover add event. In step 105, the UE 110 may transmit at least one measurement add report to the source NE 120.

[0032] In step 107, the source NE 120 may transmit at least one handover preparation request to the target NE 130. In some embodiments, the at least one handover preparation request may include at least one additional handover cause, such as radio conditions and / or load balancing. In certain embodiments, the at least one handover preparation request may include at least one indication of a conditional handover configuration, such as an indication of early triggering of conditional handover and / or for multiple targets. For example, the at least one indication of the conditional handover configuration may include at least one indication that resource reservation may be unnecessary and / or early, allowing the target NE 130 to reserve less resources than necessary. In various embodiments, the at least one handover preparation request may include at least one indication of a configuration of at least one execution condition, which triggers the conditional handover of performing preparation to the target network entity.

[0033] In some embodiments, at least one handover preparation request may include at least one value. For example, a first value, such as 0, may indicate that the conditional handover preparation is a first threshold earlier than the traditional handover, and a second value, such as 7, may indicate that the conditional handover preparation is a second threshold earlier than the traditional handover, wherein a value between the first value and the second value indicates an additional threshold between the first threshold and the second threshold. Such values ​​may provide improved granularity.

[0034] Alternatively and / or additionally, at least one handover preparation request may include one of two values, wherein a first value, such as 0, indicates strict resource reservation similar to conventional handover, and a second value, such as 1, indicates flexible resource reservation and allows the target NE 130 to reserve fewer resources than actually required, which provides the benefit of overbooking.

[0035] In some embodiments, at least one handover preparation request may include at least one extended handover cause value. For example, the handover cause value may include at least two additional values, such as "Cond-HO-strict" and "Cond-HO-relaxed".

[0036] In some embodiments, at least one handover preparation request may include at least one recommended resource reservation indication. For example, a first recommended resource reservation indication, such as 100, may indicate that the same resource reservation as the traditional handover is recommended; a second recommended resource reservation indication, such as 0, may indicate that no resource reservation is recommended; and a third resource reservation indication, such as 70, may indicate 70% of the resource reservation for the traditional handover.

[0037] In some embodiments, at least one handover preparation request may include at least one indication of a certain number of target cells, which may include source NEs 120 that may be prepared simultaneously. For example, at least one indication of a certain number of target cells may indicate a plurality of targets that may be configured in the UE 110, for example a maximum number of targets, such as 3. Additionally, of the indicated number of targets, a single target may be accessed, or none of the indicated number of targets may be accessed. This allows the following advantages: the more targets that are allowed to be configured, the more likely it is that resource reservation is unnecessary, and the fewer resources the targets may decide to reserve. In some embodiments, at least one handover preparation request may include at least one indication of a certain number of target cells, which may include source NEs 120 that have been prepared for conditional handover.

[0038] In some embodiments, at least one handover preparation request may include at least one indication of a configuration of a measurement event that triggers conditional handover preparation. For example, an offset value of an A3 condition that triggers conditional handover preparation may give an indication of the timing of the target NE 130 and / or the trigger. Alternatively or additionally, the source NE 120 may include a reference to the measurement configuration that has triggered the conditional handover. In some embodiments, at least one handover preparation request may include at least one indication.

[0039] In step 109, the target NE 130 may transmit at least one handover request confirmation to the source NE 120. In step 111, the target NE 130 may generate at least one resource reservation. In step 113, the source NE 120 may transmit at least one handover preparation cell list command to the UE 110, and in step 115, the UE 110 may transmit at least one handover command confirmation to the source NE 120.

[0040] In step 117, at least one conditional handover execution condition may be triggered in UE 110. In step 119, UE 110 may synchronize with target NE 130 and transmit at least one random access indication to target NE 130. In step 121, UE 110 may transmit at least one handover completion indication to target NE 130. In step 123, target NE 130 may transmit at least one handover completion confirmation to source NE 120. In step 125, one or more previous preparation indications associated with UE 110 and / or source NE 120 may be invalidated.

[0041] Figure 2 An example of a signaling diagram according to some embodiments is illustrated. In particular, Figure 2 The conditional handover preparation is shown. UE 210 may be similar to Figure 6 In addition, the source NE 220 and / or the target NE 230 may be similar to Figure 6 Although only a single UE, source NE and target NE are illustrated, the communication network may contain one or more of each of these entities.

[0042] In step 201, the source NE 220 may transmit at least one measurement control indication to the UE 110. In step 203, the UE 210 may generate at least one conditional handover add event. In step 205, the UE 210 may transmit at least one measurement add report to the source NE 220. In step 207, the source NE 220 may transmit at least one handover preparation request to the target NE 230. In various embodiments, the at least one handover preparation request may include at least one indication of a configuration of at least one execution condition, the at least one execution condition triggering execution of a conditional handover preparation to the target network entity.

[0043] In step 209, the target NE 230 may transmit at least one handover preparation failure indication to the source NE 220. In some embodiments, the at least one handover preparation failure indication may indicate to the source NE 220 to abort initiating conditional handover for the target NE 230 and / or fall back to conventional handover.

[0044] In some embodiments, if the target NE 230 cannot currently afford the uncertainty of conditional handover resource reservation, the at least one handover preparation failure indication may include at least one indication that future handovers will fall back to conventional procedures and / or will no longer initiate conditional handovers, which may reduce signaling overhead.

[0045] Figure 3 The diagram shows the target NE, e.g. Figure 6In step 301, the target NE can be obtained from, for example, Figure 6 The source NE of the source NE 620 in receives at least one handover preparation request. In some embodiments, the at least one handover preparation request may include at least one indication of a conditional handover configuration, such as an indication for multiple targets and / or an early triggering of the conditional handover. For example, the at least one indication of the conditional handover configuration may include at least one indication that at least one resource reservation may be unnecessary and / or early, allowing the target NE to reserve less resources than necessary. In various embodiments, the at least one handover preparation request may include at least one indication of a configuration of at least one execution condition, which triggers the conditional handover of the execution preparation to the target network entity.

[0046] In some embodiments, at least one handover preparation request may include at least one value. For example, a first value, such as 0, may indicate that the conditional handover preparation is a first threshold earlier than the traditional handover, and a second value, such as 7, may indicate that the conditional handover preparation is a second threshold earlier than the traditional handover, and a value between the first value and the second value indicates an additional threshold between the first threshold and the second threshold. Such values ​​may provide improved granularity.

[0047] Alternatively and / or additionally, at least one handover preparation request may include one of two values, wherein a first value, such as 0, indicates strict resource reservation similar to conventional handover, and a second value, such as 1, indicates flexible resource reservation, allowing the target NE to reserve fewer resources than actually required, which provides the benefit of overbooking.

[0048] In some embodiments, at least one handover preparation request may include at least one extended handover cause value. For example, the handover cause value may include at least two additional values, such as "Cond-HO-strict" and "Cond-HO-relaxed".

[0049] In some embodiments, at least one handover preparation request may include at least one recommended resource reservation indication. For example, a first recommended resource reservation indication, such as 100, may indicate that the same resource reservation as the traditional handover is recommended; a second recommended resource reservation indication, such as 0, may indicate that no resource reservation is recommended; and a third resource reservation indication, such as 70, may indicate 70% of the resource reservation for the traditional handover.

[0050] In some embodiments, at least one handover preparation request may include at least one indication of a certain number of target cells, which may include source NEs that may be prepared simultaneously. For example, at least one indication of a certain number of target cells may indicate multiple targets to be configured in the UE. This has the following advantages: the more targets are allowed to be configured, the more likely unnecessary resource reservations are, and the fewer resources the targets may decide to reserve.

[0051] In some embodiments, at least one handover preparation request may include at least one indication of a number of target cells, which may include source NEs that have been prepared for conditional handover. Additionally, at least one handover preparation request may include at least one indication of whether a number of targets have been prepared and how a number of targets have been prepared.

[0052] In some embodiments, at least one handover preparation request may include at least one indication of the configuration of a measurement event that has triggered the conditional handover preparation. For example, the offset value of the A3 condition that triggered the conditional handover preparation may give an indication of the target NE and / or the timing of the trigger.

[0053] In step 303, the target NE may transmit at least one handover request confirmation to the source NE. In step 305, the target NE may generate at least one resource reservation. In step 307, the target NE may select from a plurality of resource reservations, such as Figure 6 The UE 610 in the target NE may receive at least one synchronization and / or random access indication. In step 309, the target NE may receive at least one handover completion indication from the source NE. In step 311, the target NE may transmit at least one handover completion confirmation to the source NE.

[0054] In some embodiments, the target NE may transmit at least one handover preparation failure indication to the source NE. In some embodiments, the at least one handover preparation failure indication may indicate to the source NE to abort initiating conditional handover for the target NE and / or fall back to conventional handover.

[0055] In some embodiments, if the target NE cannot currently withstand the uncertainty of conditional switching resource reservation, at least one switching preparation failure indication may include at least one indication that future switching should fall back to traditional procedures and / or conditional switching should no longer be initiated, which can reduce signaling overhead.

[0056] In some embodiments, the target NE may generate at least one conditional handover cancellation command and / or may transmit at least one conditional handover cancellation command to the target NE. The target NE may then receive at least one conditional handover cancellation confirmation from the source NE. The target NE may then release at least one resource reservation.

[0057] Figure 4 The diagram shows a method for transmitting a signal to a user device (eg, Figure 6 An example of a method performed by a user equipment 610 in step 401. In step 403, the UE may generate at least one conditional handover addition event. In step 405, the UE may transmit at least one measurement addition report to the source NE. In step 407, the UE may receive at least one handover preparation cell list command from the source NE. In step 409, the UE may transmit at least one handover command confirmation to the source NE. In step 411, the UE may generate at least one conditional handover execution condition. In step 413, the UE may transmit at least one synchronization and / or random access indication to the target NE. In step 415, the UE may transmit at least one handover completion indication to the target NE. In step 417, one or more previous preparation indications associated with the UE may be invalidated.

[0058] Figure 5 The diagram shows a source NE (e.g. Figure 6 In step 501, the source NE may send a signal to the UE (eg, Figure 6 In step 503, the source NE may receive at least one measurement addition report from the UE.

[0059] In step 505, the source NE may send a Figure 6 In some embodiments, the at least one handover preparation request may include at least one indication of a conditional handover configuration, such as an indication of early triggering of a conditional handover for multiple targets and / or conditional handover. For example, the at least one indication of the conditional handover configuration may include at least one indication that at least one resource reservation may be unnecessary and / or early, allowing the target NE to reserve less resources than necessary.

[0060] In some embodiments, at least one handover preparation request may include at least one value. For example, a first value, such as 0, may indicate that the conditional handover preparation is a first threshold earlier than the traditional handover, and a second value, such as 7, may indicate that the conditional handover preparation is a second threshold earlier than the traditional handover, and a value between the first value and the second value indicates an additional threshold between the first threshold and the second threshold. Such values ​​may provide improved granularity.

[0061] Alternatively and / or additionally, at least one handover preparation request may include one of two values, wherein a first value, such as 0, indicates strict resource reservation similar to a conventional handover, and a second value, such as 1, indicates flexible resource reservation, allowing the target NE to reserve fewer resources than actually required, which provides the benefit of overbooking.

[0062] In some embodiments, at least one handover preparation request may include at least one extended handover cause value. For example, the handover cause value may include at least two additional values, such as "Cond-HO-strict" and "Cond-HO-relaxed".

[0063] In some embodiments, at least one handover preparation request may include at least one recommended resource reservation indication. For example, a first recommended resource reservation indication, such as 100, may indicate that the same resource reservation as the traditional handover is recommended; a second recommended resource reservation indication, such as 0, may indicate that no resource reservation is recommended; and a third resource reservation indication, such as 70, may indicate 70% of the resource reservation for the traditional handover.

[0064] In some embodiments, at least one handover preparation request may include at least one indication of a number of target cells, which may include source NEs that may be prepared simultaneously. For example, at least one indication of a number of target cells may indicate multiple targets to be configured in the UE. This has the following advantages: the more targets are allowed to be configured, the more likely unnecessary resource reservations are, and the fewer resources the targets may decide to reserve.

[0065] In some embodiments, at least one handover preparation request may include at least one indication of a number of target cells, which may include source NEs that have been prepared for conditional handover. Additionally, at least one handover preparation request may include at least one indication of whether and how many targets have been prepared.

[0066] In some embodiments, at least one handover preparation request may include at least one indication of configuration of a measurement event triggering conditional handover preparation. For example, an offset value of an A3 condition triggering conditional handover preparation may give an indication of the target NE and / or the timing of the trigger.

[0067] In some embodiments, the at least one indication of a conditional handover configuration may include an indication that the configuration shares at least one parameter with at least one legacy handover and / or that a single target is allowed.

[0068] In step 507, the source NE may receive at least one handover request confirmation. Alternatively, the source NE may receive at least one handover preparation failure indication from the target NE. In some embodiments, the at least one handover preparation failure indication may indicate to the source NE to abort initiating a conditional handover for the target NE and / or fall back to a conventional handover. In various embodiments, the at least one handover preparation request may include an indication of a configuration of at least one execution condition, the at least one execution condition triggering a conditional handover of execution preparation to the target network entity.

[0069] In some embodiments, if the target NE cannot currently withstand the uncertainty of conditional switching resource reservation, at least one switching preparation failure indication may include at least one indication that future switching should fall back to traditional procedures and / or conditional switching should no longer be initiated, which can reduce signaling overhead.

[0070] In step 509, the source NE may transmit at least one handover preparation cell list command to the UE. In step 511, the source NE may receive at least one handover command confirmation from the UE. In step 511, the source NE may receive at least one handover completion confirmation from the target NE.

[0071] Figure 6 An example of a system according to some embodiments is illustrated. In one embodiment, the system may include a plurality of devices, such as, for example, a user equipment 610 , a source network entity 620 , and a target network entity 630 .

[0072] UE 610 may include one or more of the following: a mobile device such as a mobile phone, a smart phone, a personal digital assistant (PDA), a tablet computer or portable media player, a digital camera, a camcorder, a video game console, a navigation unit such as a global positioning system (GPS) device, a desktop or laptop computer, a single location device such as a sensor or a smart meter, or any combination thereof.

[0073] The source network entity 620 and / or the target network entity 630 may be one or more of: a base station such as an evolved Node B (eNB) or a next generation Node B (gNB), a next generation radio access network (NG RAN), a serving gateway, a server and / or any other access node or a combination thereof.

[0074] One or more of these devices may include at least one processor indicated as 611, 621, and 631, respectively. At least one memory may be provided in one or more of the devices indicated at 612, 622, and 632. It may be fixed or removable. The memory may include computer program instructions or computer code contained therein. The processors 611, 621, and 631 and the memories 612, 622, and 632, or a subset thereof, may be configured to provide communication with Figure 1-Figure 5 Components corresponding to the various blocks of FIG. Although not shown, the device may also include positioning hardware such as a global positioning system (GPS) or micro-electromechanical system (MEMS) hardware, which may be used to determine the location of the device. Other sensors such as a barometer, a compass, etc. are also allowed and may be included to determine the location, altitude, direction, etc.

[0075] like Figure 6 As shown in , transceivers 613, 623, and 633 may be provided, and one or more devices may also include at least one antenna, illustrated as 614, 624, and 634, respectively. A device may have many antennas, such as an antenna array configured for multiple-input multiple-output (MIMO) communication, or multiple antennas for multiple radio access technologies. For example, other configurations of these devices may be provided.

[0076] The transceivers 613 , 623 , and 633 may be transmitters, receivers, or both transmitters and receivers, or may be units or devices configured for transmission and reception.

[0077] Processors 611, 621, and 631 may be embodied by any computing or data processing device, such as a central processing unit (CPU), an application specific integrated circuit (ASIC), or the like. The processor may be implemented as a single controller or multiple controllers or processors.

[0078] Memories 612, 622, and 632 may independently be any suitable storage device, such as a non-transitory computer readable medium. A hard disk drive (HDD), random access memory (RAM), flash memory, or other suitable memory may be used. The memory may be combined as a processor on a single integrated circuit, or may be separate from one or more processors. In addition, the computer program instructions stored in the memory and that may be processed by the processor may be computer program code in any suitable form, such as a compiled or interpreted computer program written in any suitable programming language. The memory may be removable or non-removable.

[0079] The memory and computer program instructions can be configured with a processor for a particular device to cause a hardware device such as a user device to perform any of the processes described below (see, for example, Figure 1-Figure 5 ). Thus, in some embodiments, a non-transitory computer-readable medium may be encoded with computer instructions that, when executed in hardware, perform a process such as one of the processes described herein. Alternatively, some embodiments may be performed entirely in hardware.

[0080] In some embodiments, an apparatus may include a device configured to perform Figure 1-Figure 5A circuit system for any process or function illustrated in . For example, the circuit system may be a hardware-only circuit implementation, such as an analog and / or digital circuit system. In another example, the circuit system may be a combination of hardware circuits and software, such as a combination of (one or more) analog and / or digital hardware circuits with software or firmware, and / or any portion of (one or more) hardware processors with software (including (one or more) digital signal processors), software, and at least one memory, which work together to enable the device to perform various processes or functions. In yet another example, the circuit system may be (one or more) hardware circuits and / or (one or more) processors, such as (one or more) microprocessors or a portion of (one or more) microprocessors, which includes software such as operating firmware. The software in the circuit system may not be present when it is not required for the operation of the hardware.

[0081] The features, structures or characteristics of certain embodiments described throughout the specification may be combined in any suitable manner in one or more embodiments. For example, throughout the specification, the use of the phrases "certain embodiments," "some embodiments," "other embodiments," or other similar language refers to the fact that a particular feature, structure or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present invention. Therefore, throughout the specification, the appearance of the phrases "in certain embodiments," "in some embodiments," "in other embodiments," or other similar language does not necessarily refer to the same set of embodiments, and the described features, structures or characteristics may be combined in any suitable manner in one or more embodiments.

[0082] Those of ordinary skill in the art will readily appreciate that certain embodiments discussed above may be practiced with steps in a different order and / or with hardware elements in a configuration different from that disclosed. Therefore, it will be apparent to those skilled in the art that certain modifications, variations, and alternative configurations will be apparent while still being within the spirit and scope of the present invention. Therefore, in order to determine the limits of the present invention, reference should be made to the appended claims.

[0083] Partial Glossary

[0084] 3GPP Third Generation Partnership Project

[0085] 4G Fourth generation mobile network

[0086] 5G fifth generation mobile network

[0087] CHO Conditional Switching

[0088] eNB Evolved Node B

[0089] gNB New Radio Base Station

[0090] GPS Global Positioning System

[0091] HO Handover

[0092] LTE Long Term Evolution

[0093] NG-RAN Next Generation Radio Access Network

[0094] NE Network Entity

[0095] NR New Radio

[0096] PDA Personal Digital Assistant

[0097] RACH Random Access Channel

[0098] SON Self-Organizing Network

[0099] UE User Equipment

[0100] VoIP Voice over Internet Protocol

Claims

1. A method for communication, comprising: Transmitting, by a source network entity, at least one handover preparation request to a target network entity, the at least one handover preparation request comprising at least one extended indication; receiving, by the source network entity, at least one handover request response from the target network entity in response to the at least one handover preparation request; as well as transmitting, by the source network entity, at least one handover command to at least one user equipment based on the at least one handover request response, The at least one extended indication is configured to allow the target network entity to reserve fewer resources than required.

2. The method according to claim 1, wherein the at least one extended indication comprises at least one handover cause indication, wherein the at least one handover cause indication comprises one or more of at least one radio condition indication and at least one load balancing indication.

3. A method for communication, comprising: Transmitting, by a source network entity, at least one handover preparation request to a target network entity, the at least one handover preparation request comprising at least one extended indication; receiving, by the source network entity, at least one handover request response from the target network entity in response to the at least one handover preparation request; as well as transmitting, by the source network entity, at least one handover command to at least one user equipment based on the at least one handover request response, The at least one extended indication includes at least one recommended resource reservation indication, and the at least one recommended resource reservation indication includes: The resource reservation indication is configured to recommend at least a predetermined percentage of resource reservation for conventional handover.

4. The method according to claim 3, wherein the at least one extended indication comprises at least one indication of a certain number of target cells that the target network entity can prepare simultaneously, wherein the at least one indication of a certain number of target cells that the target network entity can prepare simultaneously comprises one or more of the following: Maximum number of at least one target; at least one indication that a single target may be accessed; and At least one indication that an indicated number of targets are not accessible.

5. The method of claim 3, wherein the at least one indication of a number of target cells that the target network entity can prepare simultaneously comprises the source network entity.

6. The method of claim 3, wherein the at least one extended indication comprises: At least one indication of configuration of at least one measurement event, the at least one measurement event triggering conditional handover preparation, wherein the at least one indication of configuration of at least one measurement event comprises: at least one offset value of at least one A3 condition triggering the conditional handover preparation.

7. The method of claim 3, wherein the at least one extended indication comprises at least one indication of configuration of at least one execution condition, the at least one execution condition triggering the conditional handover of execution preparation towards the target network entity.

8. The method of claim 3, wherein the at least one handover request response is configured to cause the source network entity to perform one or more of the following: ceasing to initiate conditional handover to the target network entity for the user equipment, and permitting conventional handover for other user equipment; aborting initiation of conditional handover to the target network entity as long as the bearer configuration has not changed for the user equipment and permitting conventional handover for other user equipment; aborting initiating a conditional handover to the target network entity for any user equipment in the associated cell; and The initiation of conditional handover to the target network entity is suspended within a predetermined time period, and the conditional handover to the target network entity is resumed after the predetermined time period expires.

9. The method of claim 3, wherein the at least one handover request response comprises one or more of at least one special cause value and at least one information element.

10. The method of claim 3, wherein the at least one handover preparation request comprises at least one HOREQUEST message.

11. The method according to any one of claims 3-10, wherein the at least one handover request response comprises at least one HO PREPARATION FAILURE message.

12. An apparatus for communication, comprising at least one processor and at least one memory, the at least one memory comprising computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to perform a process according to any one of claims 1-11.

13. A non-transitory computer readable medium encoding instructions which, when executed in hardware, perform the process according to any one of claims 1-11.

14. An apparatus for communication, comprising means for performing a procedure according to any one of claims 1-11.

15. An apparatus for communication, comprising a circuit system configured to cause the apparatus to perform a process according to any one of claims 1-11.

16. A computer program product comprising a computer program which, when executed by a processor of an apparatus, causes the apparatus to perform a process according to any one of claims 1 to 11.

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