Patent Description:
Among other things, embodiments of the present disclosure are directed to command handling for simultaneous connectivity handovers. Some embodiments may operate in conjunction with multiple target cells.

<CIT> discloses a system for handover between different network technologies. <CIT> discloses a process for handling multiple handover commands at a UE.

3GPP documents R2-<NUM>, R2-<NUM>, R2-<NUM>, and R2-<NUM> discuss an evaluation of performance of conditional handover and associated implications. <CIT> discloses a process for managing handover between a plurality of candidate cells.

<CIT> discloses a process for link switching in a cellular network with the option of conditional switches.

In particular, the present invention is based on the first and second aspects disclosed below in the section named "Summary of aspects".

Unless specifically mentioned, the term "embodiment" used throughout the description does not necessarily mean "embodiment of the invention".

Embodiments discussed herein may relate to command handling for simultaneous connectivity handovers. Other embodiments may be described and/or claimed.

The following detailed description refers to the accompanying drawings. The same reference numbers may be used in different drawings to identify the same or similar elements. In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular structures, architectures, interfaces, techniques, etc., in order to provide a thorough understanding of the various aspects of the claimed invention. However, it will be apparent to those skilled in the art having the benefit of the present disclosure that the various aspects of the invention claimed may be practiced in other examples that depart from these specific details. In certain instances, descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

Various aspects of the illustrative embodiments will be described using terms commonly employed by those skilled in the art to convey the substance of their work to others skilled in the art. However, it will be apparent to those skilled in the art that alternate embodiments may be practiced with only some of the described aspects. For purposes of explanation, specific numbers, materials, and configurations are set forth in order to provide a thorough understanding of the illustrative embodiments. However, it will be apparent to one skilled in the art that alternate embodiments may be practiced without the specific details. In other instances, well-known features are omitted or simplified in order not to obscure the illustrative embodiments.

Further, various operations will be described as multiple discrete operations, in turn, in a manner that is most helpful in understanding the illustrative embodiments; however, the order of description should not be construed as to imply that these operations are necessarily order dependent. In particular, these operations need not be performed in the order of presentation.

The phrase "in various embodiments," "in some embodiments," and the like may refer to the same, or different, embodiments. The terms "comprising," "having," and "including" are synonymous, unless the context dictates otherwise. The phrase "A and/or B" means (A), (B), or (A and B). The phrases "A/B" and "A or B" mean (A), (B), or (A and B), similar to the phrase "A and/or B. " For the purposes of the present disclosure, the phrase "at least one of A and B" means (A), (B), or (A and B). The description may use the phrases "in an embodiment," "in embodiments," "in some embodiments," and/or "in various embodiments," which may each refer to one or more of the same or different embodiments.

Examples of embodiments may be described as a process depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations may be performed in parallel, concurrently, or simultaneously. In addition, the order of the operations may be rearranged. A process may be terminated when its operations are completed, but may also have additional steps not included in the figure(s). A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, and the like. When a process corresponds to a function, its termination may correspond to a return of the function to the calling function and/or the main function.

Examples of embodiments may be described in the general context of computer-executable instructions, such as program code, software modules, and/or functional processes, being executed by one or more of the aforementioned circuitry. The program code, software modules, and/or functional processes may include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular data types. The program code, software modules, and/or functional processes discussed herein may be implemented using existing hardware in existing communication networks. For example, program code, software modules, and/or functional processes discussed herein may be implemented using existing hardware at existing network elements or control nodes.

Embodiments of this disclosure may be generally related to Mobility enhancements in evolved universal terrestrial radio access network (E-UTRAN) systems. Among other things, embodiments of the present disclosure may help reduce user data interruption during handover, which targets as close as possible to <NUM>, (e.g., relaxed requirements could be considered). Embodiments of the present disclosure may further help improve system robustness during handover.

Embodiments of the present disclosure may operate with simultaneous connectivity with different cells (e.g., both a source and target eNB), and conditional handover enhancements to make-before-break, including support of carrier aggregation in source and carrier aggregation in a target eNB during handover, and performing down selection or merger, if necessary.

<FIG> illustrates an example of a conditional handover signaling flow where multiple potential target cells may trigger the UE, which may be similar to UE XQO01 of Fig. XQ, to send a measurement report. In a conditional handover, a low threshold may be configured to the UE to trigger early measurement reporting. After the source cell reserves the resource (e.g., prepares the target cell), the HO command may be sent to the UE along with a high threshold configuration (this may be configured together with the low threshold). Multiple HO commands may be sent to the UE due to multiple potential target cell satisfying the low threshold. This may result in multiple target cells preparation. Therefore, more signaling overhead in the air interface and X2 is incurred due to multiple measurement reports, target cells preparation and HO commands.

In these embodiments, if only a single HO command is valid, the latest HO command may always override the previous HO command. For example, consider the scenario where multiple target cells satisfy some configured event and UE has sent the measurement report to the source cell:.

In this embodiment, since the last HO command overrides the previous one and if multiple cells are permitted to be prepared, both cells will need to be included in the HO command.

In this option, the source may save the previous HO command (cell A in the example above) then forward to the target cell. The target cell includes the configuration of cell A and forwards it to the source cell. If multiple cells are prepared, all prepared configured cells will need to forward from the source cell to the target cell. The source cell will forward the configuration information to the UE.

In this option, the target cell sends configuration information and generates the HO command similar to the legacy procedure. The Source cell concatenates the previous HO command together with the new HO command and sends it to the UE.

For the target cell that network wants to de-configure, the source cell can simply not include it in the latest HO command. Some target cells may send a de-configuration request to the source cell if a resource is no longer available.

Similarly, if some exit condition applies to some of the prepared cells, such as use of a timer or channel condition, the UE may send an indication to source cell and the source cell can remove it from the HO command.

In these embodiments, if all HO commands are valid until an exit condition or explicit indication of de-configuration, then the UE may maintain all HO command states. In this case, the source will only prepare one cell at a time after receiving a measurement report. The target may generate the CHO command and the source will forward the CHO command to the UE. When some CHO command exit condition has been met, the UE may or may not indicate the exit condition to the source. Source may send indication to the related cell to release resources.

If one or more cells are no longer available, those cells may send an indication to the source cell and send an explicit de-configuration message to the UE to release the CHO for the particular cell. In some cases, an indication to release all CHO is possible.

These embodiments may be a hybrid between single and multiple HO command. However, since each prepared cell configuration is already sent to the UE, the UE may use the last HO command has the valid HO command. But the last HO command contains an indication of all previous valid HO command. If an indication is not given, it means those cells are no longer valid. The indication may use PCI or PCI + frequency or HO ID if exist. All other conditions may apply to this embodiment.

When CHO and legacy HO commands are sent to the UE, embodiments of the present disclosure may operate in accordance with the following options:.

In cases where multiple cells satisfy a condition at the same time, the network may indicate in the HO command which cell should have the higher priority to handover to. The UE then may, based on the priority, perform the handover if the cell also satisfies the condition. Otherwise, the cell satisfying the condition sooner should be selected for handover, even if it has a lower priority.

<FIG> illustrates an architecture of a system <NUM> of a network in accordance with some embodiments. The system <NUM> is shown to include a user equipment (UE) <NUM> and a UE <NUM>. The UEs <NUM> and <NUM> are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices connectable to one or more cellular networks), but may also comprise any mobile or non-mobile computing device, such as Personal Data Assistants (PDAs), pagers, laptop computers, desktop computers, wireless handsets, or any computing device including a wireless communications interface.

In some embodiments, any of the UEs <NUM> and <NUM> can comprise an Internet of Things (IoT) UE, which can comprise a network access layer designed for low-power IoT applications utilizing short-lived UE connections. An IoT UE can utilize technologies such as machine-to-machine (M2M) or machine-type communications (MTC) for exchanging data with an MTC server or device via a public land mobile network (PLMN), Proximity-Based Service (ProSe) or device-to-device (D2D) communication, sensor networks, or IoT networks. The M2M or MTC exchange of data may be a machine-initiated exchange of data. An IoT network describes interconnecting IoT UEs, which may include uniquely identifiable embedded computing devices (within the Internet infrastructure), with short-lived connections. The IoT UEs may execute background applications (e.g., keep-alive messages, status updates, etc.) to facilitate the connections of the IoT network.

The UEs <NUM> and <NUM> may be configured to connect, e.g., communicatively couple, with a radio access network (RAN) <NUM> - the RAN <NUM> may be, for example, an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), a NextGen RAN (NG RAN), or some other type of RAN. The UEs <NUM> and <NUM> utilize connections <NUM> and <NUM>, respectively, each of which comprises a physical communications interface or layer (discussed in further detail below); in this example, the connections <NUM> and <NUM> are illustrated as an air interface to enable communicative coupling, and can be consistent with cellular communications protocols, such as a Global System for Mobile Communications (GSM) protocol, a code-division multiple access (CDMA) network protocol, a Push-to-Talk (PTT) protocol, a PTT over Cellular (POC) protocol, a Universal Mobile Telecommunications System (UMTS) protocol, a 3GPP Long Term Evolution (LTE) protocol, a fifth generation (<NUM>) protocol, a New Radio (NR) protocol, and the like.

Some embodiments may use concepts for resource allocation for control channel information that are an extension of the above-described concepts. For example, some embodiments may utilize an enhanced physical downlink control channel (EPDCCH) that uses PDSCH resources for control information transmission. The EPDCCH may be transmitted using one or more enhanced control channel elements (ECCEs). Similar to above, each ECCE may correspond to nine sets of four physical resource elements known as enhanced resource element groups (EREGs). An ECCE may have other numbers of EREGs in some situations.

The RAN <NUM> is shown to be communicatively coupled to a core network (CN) <NUM> -via an S1 interface <NUM>. In embodiments, the CN <NUM> may be an evolved packet core (EPC) network, a NextGen Packet Core (NPC) network, or some other type of CN. In this embodiment, the S1 interface <NUM> is split into two parts: the S1-U interface <NUM>, which carries traffic data between the RAN nodes <NUM> and <NUM> and the serving gateway (S-GW) <NUM>, and the S1-mobility management entity (MME) interface <NUM>, which is a signaling interface between the RAN nodes <NUM> and <NUM> and MMEs <NUM>.

The P-GW <NUM> may route data packets between the EPC network and external networks such as a network including the application server <NUM> (alternatively referred to as application function (AF)) via an Internet Protocol (IP) interface <NUM>.

<FIG> illustrates example components of a device <NUM> in accordance with some embodiments. In some embodiments, the device <NUM> may include application circuitry <NUM>, baseband circuitry <NUM>, Radio Frequency (RF) circuitry <NUM>, front-end module (FEM) circuitry <NUM>, one or more antennas <NUM>, and power management circuitry (PMC) <NUM> coupled together at least as shown. The components of the illustrated device <NUM> may be included in a UE or a RAN node. In some embodiments, the device <NUM> may include fewer elements (e.g., a RAN node may not utilize application circuitry <NUM>, and instead include a processor/controller to process IP data received from an EPC). In some embodiments, the device <NUM> may include additional elements such as, for example, memory/storage, display, camera, sensor, or input/output (I/O) interface. In other embodiments, the components described below may be included in more than one device (e.g., said circuitries may be separately included in more than one device for Cloud-RAN (C-RAN) implementations).

The baseband circuitry <NUM> may include one or more baseband processors or control logic to process baseband signals received from a receive signal path of the RF circuitry <NUM> and to generate baseband signals for a transmit signal path of the RF circuitry <NUM>. Baseband processing circuitry <NUM> may interface with the application circuitry <NUM> for generation and processing of the baseband signals and for controlling operations of the RF circuitry <NUM>. For example, in some embodiments, the baseband circuitry <NUM> may include a third generation (<NUM>) baseband processor 604A, a fourth generation (<NUM>) baseband processor 604B, a fifth generation (<NUM>) baseband processor 604C, or other baseband processor(s) 604D for other existing generations, generations in development or to be developed in the future (e.g., second generation (<NUM>), sixth generation (<NUM>), etc.). The baseband circuitry <NUM> (e.g., one or more of baseband processors 604A-D) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry <NUM>. In other embodiments, some or all of the functionality of baseband processors 604A-D may be included in modules stored in the memory <NUM> and executed via a Central Processing Unit (CPU) 604E. The radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, etc. In some embodiments, modulation/demodulation circuitry of the baseband circuitry <NUM> may include Fast-Fourier Transform (FFT), precoding, or constellation mapping/demapping functionality. In some embodiments, encoding/decoding circuitry of the baseband circuitry <NUM> may include convolution, tail-biting convolution, turbo, Viterbi, or Low Density Parity Check (LDPC) encoder/decoder functionality. Embodiments of modulation/demodulation and encoder/decoder functionality are not limited to these examples and may include other suitable functionality in other embodiments.

In some embodiments, the baseband circuitry <NUM> may include one or more audio digital signal processor(s) (DSP) 604F. The audio DSP(s) 604F may be include elements for compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments. Components of the baseband circuitry may be suitably combined in a single chip, a single chipset, or disposed on a same circuit board in some embodiments. In some embodiments, some or all of the constituent components of the baseband circuitry <NUM> and the application circuitry <NUM> may be implemented together such as, for example, on a system on a chip (SOC).

RF circuitry <NUM> may include a receive signal path which may include circuitry to downconvert RF signals received from the FEM circuitry <NUM> and provide baseband signals to the baseband circuitry <NUM>.

In some embodiments, the receive signal path of the RF circuitry <NUM> may include mixer circuitry 606a, amplifier circuitry 606b and filter circuitry 606c. In some embodiments, the transmit signal path of the RF circuitry <NUM> may include filter circuitry 606c and mixer circuitry 606a. RF circuitry <NUM> may also include synthesizer circuitry 606d for synthesizing a frequency for use by the mixer circuitry 606a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry 606a of the receive signal path may be configured to downconvert RF signals received from the FEM circuitry <NUM> based on the synthesized frequency provided by synthesizer circuitry 606d. The amplifier circuitry 606b may be configured to amplify the down-converted signals and the filter circuitry 606c may be a low-pass filter (LPF) or bandpass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry <NUM> for further processing. In some embodiments, the output baseband signals may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, mixer circuitry 606a of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuitry 606a of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry 606d to generate RF output signals for the FEM circuitry <NUM>. The baseband signals may be provided by the baseband circuitry <NUM> and may be filtered by filter circuitry 606c.

In some embodiments, the mixer circuitry 606a of the receive signal path and the mixer circuitry 606a of the transmit signal path may include two or more mixers and may be arranged for quadrature downconversion and upconversion, respectively. In some embodiments, the mixer circuitry 606a of the receive signal path and the mixer circuitry 606a of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry 606a of the receive signal path and the mixer circuitry 606a of the transmit signal path may be arranged for direct downconversion and direct upconversion, respectively. In some embodiments, the mixer circuitry 606a of the receive signal path and the mixer circuitry 606a of the transmit signal path may be configured for superheterodyne operation.

In some embodiments, the synthesizer circuitry 606d may be a fractional-N synthesizer or a fractional N/N+<NUM> synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry 606d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider.

The synthesizer circuitry 606d may be configured to synthesize an output frequency for use by the mixer circuitry 606a of the RF circuitry <NUM> based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry 606d may be a fractional N/N+<NUM> synthesizer.

Synthesizer circuitry 606d of the RF circuitry <NUM> may include a divider, a delay-locked loop (DLL), a multiplexer and a phase accumulator. In some embodiments, the divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by either N or N+<NUM> (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable, delay elements, a phase detector, a charge pump and a D-type flip-flop. In these embodiments, the delay elements may be configured to break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

In some embodiments, synthesizer circuitry 606d may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be a LO frequency (fLO). In some embodiments, the RF circuitry <NUM> may include an IQ/polar converter.

FEM circuitry <NUM> may include a receive signal path, which may include circuitry configured to operate on RF signals received from one or more antennas <NUM>, amplify the received signals and provide the amplified versions of the received signals to the RF circuitry <NUM> for further processing. FEM circuitry <NUM> may also include a transmit signal path, which may include circuitry configured to amplify signals for transmission provided by the RF circuitry <NUM> for transmission by one or more of the one or more antennas <NUM>.

The FEM circuitry <NUM> may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry <NUM> may include a low noise amplifier (LNA) to amplify received RF signals and provide the amplified received RF signals as an output (e.g., to the RF circuitry <NUM>).

<FIG> shows the PMC <NUM> coupled only with the baseband circuitry <NUM>. However, in other embodiments, the PMC <NUM> may be additionally or alternatively coupled with, and perform similar power management operations for, other components such as, but not limited to, application circuitry <NUM>, RF circuitry <NUM>, or FEM <NUM>.

If there is no data traffic activity for an extended period of time, then the device <NUM> may transition off to an RRC_Idle state, where it disconnects from the network and does not perform operations such as channel quality feedback, handover, etc. The device <NUM> goes into a very low power state and it performs paging where again it periodically wakes up to listen to the network and then powers down again. The device <NUM> may not receive data in this state, in order to receive data, it must transition back to RRC_Connected state.

For example, processors of the baseband circuitry <NUM>, alone or in combination, may be used to execute Layer <NUM>, Layer <NUM>, or Layer <NUM> functionality, while processors of the application circuitry <NUM> may utilize data (e.g., packet data) received from these layers and further execute Layer <NUM> functionality (e.g., transmission communication protocol (TCP) and user datagram protocol (UDP) layers).

<FIG> illustrates example interfaces of baseband circuitry in accordance with some embodiments. As discussed above, the baseband circuitry <NUM> of <FIG> may comprise processors 604A-604E and a memory <NUM> utilized by said processors. Each of the processors 604A-604E may include a memory interface, 704A-704E, respectively, to send/receive data to/from the memory <NUM>.

<FIG> is a block diagram illustrating components, according to some example embodiments, able to read instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium) and perform any one or more of the methodologies discussed herein. Specifically, <FIG> shows a diagrammatic representation of hardware resources <NUM> including one or more processors (or processor cores) <NUM>, one or more memory/storage devices <NUM>, and one or more communication resources <NUM>, each of which may be communicatively coupled via a bus <NUM>. For embodiments where node virtualization (e.g., NFV) is utilized, a hypervisor <NUM> may be executed to provide an execution environment for one or more network slices/sub-slices to utilize the hardware resources <NUM>.

The memory/storage devices <NUM> may include, but are not limited to, any type of volatile or non-volatile memory such as dynamic random access memory (DRAM), static random-access memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), Flash memory, solid-state storage, etc..

Instructions <NUM> may comprise software, a program, an application, an applet, an app, or other executable code for causing at least any of the processors <NUM> to perform any one or more of the methodologies discussed herein. The instructions <NUM> may reside, completely or partially, within at least one of the processors <NUM> (e.g., within the processor's cache memory), the memory/storage devices <NUM>, or any suitable combination thereof. Furthermore, any portion of the instructions <NUM> may be transferred to the hardware resources <NUM> from any combination of the peripheral devices <NUM> or the databases <NUM>. Accordingly, the memory of processors <NUM>, the memory/storage devices <NUM>, the peripheral devices <NUM>, and the databases <NUM> are examples of computer-readable and machine-readable media.

In various embodiments, the devices/components of <FIG>, and particularly the baseband circuitry of <FIG>, may be used to practice, in whole or in part, any of the operation flow/algorithmic structures depicted in <FIG>.

One example of an operation flow/algorithmic structure is depicted in <FIG>, which may be performed by an evolved NodeB (eNB) or next-generation NodeB (gNB) in accordance with some embodiments. In this example, operation flow/algorithmic structure <NUM> may include, at <NUM>, receiving, from a user equipment (UE), a first measurement report associated with a first target cell. Operation flow/algorithmic structure <NUM> may further include, at <NUM>, encoding, based on the first measurement report, a first handover request message for transmission to the first target cell, wherein the first handover request message is to prepare the first target cell for handover. Operation flow/algorithmic structure <NUM> may further include, at <NUM>, retrieving handover configuration information associated with the first target cell from the memory. Operation flow/algorithmic structure <NUM> may further include, at <NUM>, encoding for transmission to the UE, based on the first measurement report, a first conditional handover command (CHO) message that includes the handover configuration information associated with the first target cell. Operation flow/algorithmic structure <NUM> may further include, at <NUM>, receiving, from the UE, a second measurement report associated with a second target cell. Operation flow/algorithmic structure <NUM> may further include, at <NUM>, encoding, based on the second measurement report, a second handover request message for transmission to the second target cell, wherein the second handover request message is to prepare the second target cell for handover. Operation flow/algorithmic structure <NUM> may further include, at <NUM>, encoding, based on the first measurement report, a second CHO message for transmission to the UE, wherein the second CHO message includes the handover configuration information associated with the first target cell and handover configuration information associated with the second target cell.

Another example of an operation flow/algorithmic structure is depicted in <FIG>, which may be performed by a UE in accordance with some embodiments. In this example, operation flow/algorithmic structure <NUM> may include, at <NUM>, encoding, based on a determination that a measured value associated with a first target cell is below a predetermined threshold, a first measurement report message for transmission to a source cell. Operation flow/algorithmic structure <NUM> may further include, at <NUM>, receiving, from the source cell, a first conditional handover command (CHO) message that includes handover configuration information associated with the first target cell. Operation flow/algorithmic structure <NUM> may further include, at <NUM>, encoding, based on a determination that a measured value associated with a second target cell is below a predetermined threshold, a second measurement report message for transmission to the source cell. Operation flow/algorithmic structure <NUM> may further include, at <NUM>, receiving, from the source cell, a second conditional handover command (CHO) message that includes the handover configuration information associated with the first target cell and handover configuration information associated with the second target cell.

Another example of an operation flow/algorithmic structure is depicted in <FIG>, which may be performed by an evolved NodeB (eNB) or next-generation NodeB (gNB) in accordance with some embodiments. In this example, operation flow/algorithmic structure <NUM> may include, at <NUM>, receiving, from a user equipment (UE), a first measurement report associated with a first target cell. Operation flow/algorithmic structure <NUM> may further include, at <NUM>, encoding, based on the first measurement report, a first handover request message for transmission to the first target cell, wherein the first handover request message is to prepare the first target cell for handover. Operation flow/algorithmic structure <NUM> may further include, at <NUM>, encoding for transmission to the UE, based on the first measurement report, a first conditional handover command (CHO) message that includes the handover configuration information associated with the first target cell. Operation flow/algorithmic structure <NUM> may further include, at <NUM>, receiving, from the UE, a second measurement report associated with a second target cell. Operation flow/algorithmic structure <NUM> may further include, at <NUM>, encoding, based on the second measurement report, a second handover request message for transmission to the second target cell, wherein the second handover request message is to prepare the second target cell for handover. Operation flow/algorithmic structure <NUM> may further include, at <NUM>, encoding, based on the first measurement report, a second CHO message for transmission to the UE, wherein the second CHO message includes the handover configuration information associated with the first target cell and handover configuration information associated with the second target cell.

A first aspect of the invention includes an apparatus comprising: memory to store handover configuration information; and processing circuitry, coupled with the memory, to: receive, from a user equipment (UE), a first measurement report associated with a first target cell; encode, based on the first measurement report, a first handover request message for transmission to the first target cell, wherein the first handover request message is to prepare the first target cell for handover; retrieve handover configuration information associated with the first target cell from the memory; encode for transmission to the UE, based on the first measurement report, a first conditional handover command (CHO) message that includes the handover configuration information associated with the first target cell; receive, from the UE, a second measurement report associated with a second target cell; encode, based on the second measurement report, a second handover request message for transmission to the second target cell, wherein the second handover request message is to prepare the second target cell for handover; and encode, based on the first measurement report, a second CHO message for transmission to the UE, wherein the second CHO message includes the handover configuration information associated with the first target cell and handover configuration information associated with the second target cell.

In an embodiment of the first aspect of the invention, the processing circuitry is further to: receive, from the first target cell, the handover configuration information associated with the first target cell; and store the handover configuration information associated with the first target cell in the memory.

In an embodiment of the first aspect of the invention, the processing circuitry is further to: receive, from the second target cell, the handover configuration information associated with the second target cell; and store the handover configuration information associated with the second target cell in the memory.

In the first aspect of the invention, the second handover request message includes the handover configuration information associated with the first target cell.

In an embodiment of the first aspect of the invention, the processing circuitry is further to encode a third handover request message for transmission to the first target cell, the third handover request message including a de-configuration request for the first target cell.

In an embodiment of the first aspect of the invention, the processing circuitry is further to: receive, from the second target cell, a message including an indication that resources associated with the second target cell are unavailable; and encode a de-configuration message for transmission to the UE, wherein the de-configuration message is to indicate that the UE is to release the CHO for the second target cell.

In an embodiment of the first aspect of the invention, the handover configuration information associated with the second target cell includes a high threshold indicator for a measured value associated with the second target cell.

In an embodiment of the first aspect of the invention, the handover configuration information associated with the second target cell includes a low threshold indicator for a measured value associated with the second target cell.

In the first aspect of the invention, the apparatus is an evolved NodeB (eNB) or portion thereof, or a next-generation NodeB (gNB) or portion thereof.

In an aspect which is not part of the invention, the present application discloses one or more computer-readable media storing instructions that, when executed by one or more processors, cause a user equipment (UE) to: encode, based on a determination that a measured value associated with a first target cell is below a predetermined threshold, a first measurement report message for transmission to a source cell; receive, from the source cell, a first conditional handover command (CHO) message that includes handover configuration information associated with the first target cell; encode, based on a determination that a measured value associated with a second target cell is below a predetermined threshold, a second measurement report message for transmission to the source cell; and receive, from the source cell, a second conditional handover command (CHO) message that includes the handover configuration information associated with the first target cell and handover configuration information associated with the second target cell.

Optionally, in said aspect not being part of the invention the media further stores instructions for causing the UE to override the handover configuration information from the first CHO message with the handover configuration information from the second CHO message.

Optionally, in said aspect not being part of the invention the media further stores instructions for causing the UE to encode a message for transmission to the source cell that indicates an exit condition applies to the first target cell or the second target cell.

Optionally, in said aspect not being part of the invention the media further stores instructions for causing the UE to perform a synchronization and random access procedure with the second target cell.

Optionally, in said aspect not being part of the invention the media further stores instructions for causing the UE to: receive a de-configuration message from the source cell; and release the CHO for the second target cell in response based on the de-configuration message.

A second aspect of the invention includes one or more computer-readable media storing instructions that, when executed by one or more processors, cause an evolved NodeB (eNB) to: receive, from a user equipment (UE), a first measurement report associated with a first target cell; encode, based on the first measurement report, a first handover request message for transmission to the first target cell, wherein the first handover request message is to prepare the first target cell for handover; encode for transmission to the UE, based on the first measurement report, a first conditional handover command (CHO) message that includes handover configuration information associated with the first target cell; receive, from the UE, a second measurement report associated with a second target cell; encode, based on the second measurement report, a second handover request message for transmission to the second target cell, wherein the second handover request message is to prepare the second target cell for handover; and encode, based on the first measurement report, a second CHO message for transmission to the UE, wherein the second CHO message includes the handover configuration information associated with the first target cell and handover configuration information associated with the second target cell.

In an embodiment of the second aspect of the invention the media further stores instructions for causing the eNB to: receive, from the first target cell, the handover configuration information associated with the first target cell; and store the handover configuration information associated with the first target cell in the memory.

Optionally, in the second aspect of the invention the media further stores instructions for causing the eNB to: receive, from the second target cell, the handover configuration information associated with the second target cell; and store the handover configuration information associated with the second target cell in the memory.

In the second aspect of the invention, the second handover request message includes the handover configuration information associated with the first target cell.

Optionally, in the second aspect of the invention the media further stores instructions for causing the eNB to encode a third handover request message for transmission to the first target cell, the third handover request message including a de-configuration request for the first target cell.

Claim 1:
An apparatus, wherein the apparatus is an evolved NodeB, eNB, or portion thereof, or a next-generation NodeB, gNB, or portion thereof, said apparatus comprising:
memory (<NUM>) to store handover configuration information; and
processing circuitry (604E), coupled with the memory, to:
receive (<NUM>), from a user equipment, UE, a first measurement report associated with a first target cell;
encode (<NUM>), based on the first measurement report, a first handover request message for transmission to the first target cell, wherein the first handover request message is to prepare the first target cell for handover;
retrieve (<NUM>) handover configuration information associated with the first target cell from the memory;
encode (<NUM>) for transmission to the UE, based on the first measurement report, a first conditional handover command, CHO, message that includes the handover configuration information associated with the first target cell;
receive (<NUM>), from the UE, a second measurement report associated with a second target cell;
encode (<NUM>), based on the second measurement report, a second handover request message for transmission to the second target cell, wherein the second handover request message is to prepare the second target cell for handover, and wherein the second handover request message includes the handover configuration information associated with the first target cell; and
encode (<NUM>), based on the first measurement report, a second CHO message for transmission to the UE, wherein the second CHO message includes the handover configuration information associated with the first target cell and handover configuration information associated with the second target cell.