Patent Description:
The following abbreviations are herewith defined, at least some of which are referred to within the following description: Third Generation Partnership Project ("3GPP"), Positive-Acknowledgment ("ACK"), Binary Phase Shift Keying ("BPSK"), Clear Channel Assessment ("CCA"), Cyclic Prefix ("CP"), Channel State Information ("CSI"), Common Search Space ("CSS"), Discrete Fourier Transform Spread ("DFTS"), Downlink Control Information ("DCI"), Downlink ("DL"), Downlink Pilot Time Slot ("DwPTS"), Enhanced Clear Channel Assessment ("eCCA"), Enhanced Mobile Broadband ("eMBB"), Evolved Node B ("eNB"), European Telecommunications Standards Institute ("ETSI"), Frame Based Equipment ("FBE"), Frequency Division Duplex ("FDD"), Frequency Division Multiple Access ("FDMA"), Guard Period ("GP"), Hybrid Automatic Repeat Request ("HARQ"), Internet-of-Things ("IoT"), Licensed Assisted Access ("LAA"), Load Based Equipment ("LBE"), Listen-Before-Talk ("LBT"), Long Term Evolution ("LTE"), Multiple Access ("MA"), Modulation Coding Scheme ("MCS"), Machine Type Communication ("MTC"), Multiple Input Multiple Output ("MIMO"), Multi User Shared Access ("MUSA"), Narrowband ("NB"), Negative-Acknowledgment ("NACK") or ("NAK"), Next Generation Node B ("gNB"), Non-Orthogonal Multiple Access ("NOMA"), Orthogonal Frequency Division Multiplexing ("OFDM"), Primary Cell ("PCell"), Physical Broadcast Channel ("PBCH"), Physical Downlink Control Channel ("PDCCH"), Physical Downlink Shared Channel ("PDSCH"), Pattern Division Multiple Access ("PDMA"), Physical Hybrid ARQ Indicator Channel ("PHICH"), Physical Random Access Channel ("PRACH"), Physical Resource Block ("PRB"), Physical Uplink Control Channel ("PUCCH"), Physical Uplink Shared Channel ("PUSCH"), Quality of Service ("QoS"), Quadrature Phase Shift Keying ("QPSK"), Radio Resource Control ("RRC"), Random Access Procedure ("RACH"), Random Access Response ("RAR"), Reference Signal ("RS"), Resource Spread Multiple Access ("RSMA"), Round Trip Time ("RTT"), Receive ("RX"), Sparse Code Multiple Access ("SCMA"), Scheduling Request ("SR"), Single Carrier Frequency Division Multiple Access ("SC-FDMA"), Secondary Cell ("SCell"), Shared Channel ("SCH"), Signal-to-Interference-Plus-Noise Ratio ("SINR"), System Information Block ("SIB"), Transport Block ("TB"), Transport Block Size ("TBS"), Time-Division Duplex ("TDD"), Time Division.

Multiplex ("TDM"), Transmission Time Interval ("TTI"), Transmit ("TX"), Uplink Control Information ("UCI"), User Entity/Equipment (Mobile Terminal) ("UE"), Uplink ("UL"), Universal Mobile Telecommunications System ("UMTS"), Uplink Pilot Time Slot ("UpPTS"), Ultra-reliability and Low-latency Communications ("URLLC"), and Worldwide Interoperability for Microwave Access ("WiMAX"). As used herein, "HARQ-ACK" may represent collectively the Positive Acknowledge ("ACK") and the Negative Acknowledge ("NAK"). ACK means that a TB is correctly received while NAK means a TB is erroneously received.

In certain wireless communications networks, a high carrier frequency (e.g., ><NUM>) may be used, such as millimeter wave. In some networks, conditional handovers may be used. In various networks, to maintain robustness of a handover, a handover command transmitted to a UE may be configured by a serving cell and may involve multiple candidate cells with condition. If more than one candidate cell meets the condition, handover to a wrong cell may occur or a redundancy handover may occur.

In some configurations, a radio link failure ("RLF") may occur shortly after a successful handover from a source cell to a target cell, or a handover failure may occur during a handover procedure. In such configurations, the UE may attempt to re-establish a radio link connection in a cell other than the source cell and the target cell (e.g., wrong cell).

In various configurations, if a UE selects a candidate second cell as a target cell for a system in which both a candidate first cell and the candidate second cell meet a condition, and a quality of the candidate first cell is better than the candidate second cell, after the UE is handed over to the candidate second cell, a handover from the candidate second cell to the candidate first cell may occur shortly (e.g., redundancy handover).

In some configurations, after RRCConnectionReconfiguration including conditional handover is configured by a gNB and transmitted to a UE, the UE may apply this RRC configuration only when a condition is met. Before applying this RRC reconfiguration, the UE may suspend this RRC reconfiguration and evaluate whether the condition is met. As may be appreciated, more power and/or processing time may be used for such an evaluation than with another RRM measurement. This may occur because after the gNB configures the handover command and transmits the command to the UE, the handover condition may not be met for a long time. For example, after the UE moves to the cell edge, then the UE may move back to a center of the cell or may not move beyond the cell.

<NPL>, discusses conditional handover. <CIT> discloses that the number of handover-related failures that occur in a communication system may be reduced by taking target access point conditions into account when declaring radio link failure and/or by delaying certain handover operations. <CIT> discloses an apparatus for minimizing the recovery time of connecting to a network, the apparatus being configured to receive a message including a preparatory handover command indicating one or more candidate target cells for handover and data indicating that the candidate target cells are selectable for handover in response to a future detection of one or more handover conditions. <CIT> concerns radio resource management in high speed train environments.

The present invention provides a method performed by a user equipment according to claim <NUM> and a corresponding user equipment apparatus according to claim <NUM>.

<FIG> depicts an embodiment of a wireless communication system <NUM> for conditional handovers. In one embodiment, the wireless communication system <NUM> includes remote units <NUM> and base units <NUM>. Even though a specific number of remote units <NUM> and base units <NUM> are depicted in <FIG>, one of skill in the art will recognize that any number of remote units <NUM> and base units <NUM> may be included in the wireless communication system <NUM>.

The base units <NUM> may be distributed over a geographic region. In certain embodiments, a base unit <NUM> may 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. The base units <NUM> are generally part of a radio access network that includes one or more controllers communicably coupled to one or more corresponding base units <NUM>.

In one implementation, the wireless communication system <NUM> is compliant with the LTE of the 3GPP protocol, wherein the base unit <NUM> transmits using an OFDM modulation scheme on the DL and the remote units <NUM> transmit on the UL using a SC-FDMA scheme or an OFDM scheme. More generally, however, the wireless communication system <NUM> may implement some other open or proprietary communication protocol, for example, WiMAX, among other protocols.

In one embodiment, a base unit <NUM> may transmit a handover command to a remote unit <NUM>.

In certain embodiments, a remote unit <NUM> may receive a handover command involving multiple candidate cells. The remote unit <NUM> may select a target cell of the multiple candidate cells in response to the target cell meeting a predetermined condition. Accordingly, a remote unit <NUM> may be used for conditional handovers.

In various embodiments, a remote unit <NUM> may receive a handover command involving multiple candidate cells. The remote unit <NUM> may select a target cell of the multiple candidate cells in response to the target cell meeting a predetermined condition relative to other cells of the plurality of candidate cells. Accordingly, a remote unit <NUM> may be used for conditional handovers.

In some embodiments, a remote unit <NUM> may receive RRCConnectionReconfiguration including a condition for handover. The remote unit <NUM> may suspend the RRCConnectionReconfiguration until the condition for handover is met. The remote unit <NUM> may overwrite the previously suspended RRCConnectionReconfiguration including the condition for handover in response to a predetermined criteria. Accordingly, a remote unit <NUM> may be used for conditional handovers.

<FIG> depicts one embodiment of an apparatus <NUM> that may be used for conditional handovers. The apparatus <NUM> includes one embodiment of the remote unit <NUM>. Furthermore, the remote unit <NUM> may include a processor <NUM>, a memory <NUM>, an input device <NUM>, a display <NUM>, a transmitter <NUM>, and a receiver <NUM>. In some embodiments, the input device <NUM> and the display <NUM> are combined into a single device, such as a touchscreen. In certain embodiments, the remote unit <NUM> may not include any input device <NUM> and/or display <NUM>. In various embodiments, the remote unit <NUM> may include one or more of the processor <NUM>, the memory <NUM>, the transmitter <NUM>, and the receiver <NUM>, and may not include the input device <NUM> and/or the display <NUM>.

In various embodiments, the processor <NUM> selects a target cell of multiple candidate cells in response to the target cell meeting a predetermined condition. In certain embodiments, the processor <NUM> selects a target cell of multiple candidate cells in response to the target cell meeting a predetermined condition relative to other cells of the multiple candidate cells. In some embodiments, the processor <NUM> suspends an RRCConnectionReconfiguration until a condition for handover is met and overwrites the previously suspended RRCConnectionReconfiguration including a condition for handover in response to a predetermined criteria.

In some embodiments, the memory <NUM> stores data relating to handovers.

The transmitter <NUM> is used to provide UL communication signals to the base unit <NUM> and the receiver <NUM> is used to receive DL communication signals from the base unit <NUM>. In various embodiments, the receiver <NUM> may be used to receive a handover command involving multiple candidate cells. In some embodiments, the receiver <NUM> may be used to receive RRCConnectionReconfiguration including a condition for handover.

<FIG> depicts one embodiment of an apparatus <NUM> that may be used for conditional handovers. The apparatus <NUM> includes one embodiment of the base unit <NUM>. Furthermore, the base unit <NUM> may include a processor <NUM>, a memory <NUM>, an input device <NUM>, a display <NUM>, a transmitter <NUM>, and a receiver <NUM>. As may be appreciated, the processor <NUM>, the memory <NUM>, the input device <NUM>, the display <NUM>, the transmitter <NUM>, and the receiver <NUM> may be substantially similar to the processor <NUM>, the memory <NUM>, the input device <NUM>, the display <NUM>, the transmitter <NUM>, and the receiver <NUM> of the remote unit <NUM>, respectively.

In various embodiments, the transmitter <NUM> is used to transmit conditional handover commands to the remote unit <NUM>. Although only one transmitter <NUM> and one receiver <NUM> are illustrated, the base unit <NUM> may have any suitable number of transmitters <NUM> and receivers <NUM>.

<FIG> illustrates one embodiment of communications <NUM> for handovers. Specifically, communications <NUM> between a UE <NUM>, a source eNB <NUM>, a target eNB <NUM>, a mobility management entity ("MME") <NUM>, and a serving gateway <NUM> are illustrated.

In certain embodiments, a UE context <NUM> within the source eNB <NUM> may contain information regarding roaming and access restrictions which were provided either at connection establishment or at a last TA update. In some embodiments, a first communication <NUM> from the source eNB <NUM> to the UE <NUM> includes the source eNB <NUM> configuring UE measurement procedures according to roaming and access restriction information and available multiple frequency band information. Measurements provided by the source eNB <NUM> may facilitate the function controlling the UE's connection mobility.

In various embodiments, a second communication <NUM> from the UE <NUM> to the source eNB <NUM> includes a measurement report triggered and sent to the source eNB <NUM>. In certain embodiments, the source eNB <NUM> determines <NUM>, based on the measurement report and radio resource management ("RRM") information, to hand off the UE <NUM>. In a third communication <NUM> from the source eNB <NUM> to the target eNB <NUM>, the source eNB <NUM> issues a handover request message to the target eNB <NUM> passing information to prepare the handover at the target side. Admission control <NUM> may be performed by the target eNB <NUM> dependent on received QoS information to increase the likelihood of a successful handover, if the resources can be granted by target eNB <NUM>. The target eNB <NUM> configures the required resources according to the received QoS information and reserves a cell radio network temporary identifier ("C-RNTI") and optionally a RACH preamble. The configuration to be used in the target cell may either be specified independently (e.g., an establishment) or as a delta compared to the configuration used in the source cell (e.g., a reconfiguration).

In a fourth communication <NUM> from the target eNB <NUM> to the source eNB <NUM>, the target eNB <NUM> prepares a handover with L1/L2 and sends a handover request acknowledge to the source eNB <NUM>. The handover request acknowledge message includes a transparent container to be sent to the UE <NUM> as an RRC message to perform the handover. The container includes a new C-RNTI, target eNB <NUM> security algorithm identifiers for the selected security algorithms, and may include a dedicated RACH preamble, and possibly other parameters (e.g., access parameters, SIBs, etc.). The handover request acknowledge message may also include radio network layer/transmission network layer ("RNL/TNL") information for the forwarding tunnels, if necessary. In certain embodiments, as soon as the source eNB <NUM> receives the handover request acknowledge, or as soon as the transmission of the handover command is initiated in the downlink, data forwarding may be initiated.

In a fifth communication <NUM> from the source eNB <NUM> to the UE <NUM>, in response to the target eNB <NUM> generating an RRC message to perform the handover (e.g., RRCConnectionReconfiguration message including the mobilityControlInformation), the source eNB <NUM> transmits the RRC message to the UE <NUM>. The source eNB <NUM> performs the necessary integrity protection and ciphering of the message. The UE <NUM> receives the RRCConnectionReconfiguration message with necessary parameters (e.g., new C-RNTI, target eNB <NUM> security algorithm identifiers, and optionally dedicated RACH preamble, target eNB <NUM> SIBs, etc.) and is commanded by the source eNB <NUM> to perform the handover. The UE <NUM> does not need to delay the handover execution for delivering the HARQ/ARQ responses to the source eNB <NUM>.

In a sixth communication <NUM> from the source eNB <NUM> to the target eNB <NUM>, the source eNB <NUM> sends a SN status transfer message to the target eNB <NUM> to convey an uplink packet data convergence protocol ("PDCP") SN receiver status and a downlink PDCP SN transmitter status of enhanced radio access bearers ("E-RABs") for which PDCP status preservation applies. The uplink PDCP SN receiver status includes at least the PDCP SN of a first missing UL service data unit ("SDU") and may include a bit map of the receive status of the out of sequence UL SDUs that the UE <NUM> needs to retransmit in the target cell, if there are any such SDUs. The downlink PDCP SN transmitter status indicates the next PDCP SN that the target eNB <NUM> may assign to new SDUs, not having a PDCP SN yet. The source eNB <NUM> may omit sending this message if none of the E-RABs of the UE <NUM> are to be treated with PDCP status preservation.

In a seventh communication <NUM> from the UE <NUM> to the target eNB <NUM>, after receiving the RRCConnectionReconfiguration message including the mobilityControlInformation, the UE <NUM> performs synchronization to the target eNB <NUM> and accesses the target cell via RACH, following a contention-free procedure if a dedicated RACH preamble was indicated in the mobilityControlInformation, or following a contention-based procedure if no dedicated preamble was indicated. The UE <NUM> derives target eNB <NUM> specific keys and configures the selected security algorithms to be used in the target cell.

In an eighth communication <NUM> from the target eNB <NUM> to the UE <NUM>, thee target eNB <NUM> responds with UL allocation and timing advance. In a ninth communication <NUM> from the UE <NUM> to the target eNB <NUM>, the UE <NUM> has successfully accessed the target cell and the UE <NUM> sends an RRCConnectionReconfigurationComplete message (e.g., including C-RNTI) to confirm the handover, along with an uplink buffer status report, whenever possible, to the target eNB <NUM> to indicate that the handover procedure is completed for the UE <NUM>. The target eNB <NUM> verifies the C-RNTI sent in the RRCConnectionReconfigurationComplete message. The target eNB <NUM> may then begin sending data to the UE <NUM>.

In a tenth communication <NUM> from the target eNB <NUM> to the MME <NUM>, the target eNB <NUM> sends a path switch request message to the MME <NUM> to inform the MME <NUM> that the UE <NUM> has changed cell. In an eleventh communication <NUM> from the MME <NUM> to the serving gateway <NUM>, the MME <NUM> sends a modify bearer request message to the serving gateway <NUM>. The serving gateway <NUM> switches <NUM> the downlink data path to the target side. The serving gateway <NUM> may send one or more end marker packets on the old path to the source eNB <NUM> and then may release any U-plane/TNL resources towards the source eNB <NUM>.

In a twelfth communication <NUM> from the serving gateway <NUM> to the MME <NUM>, the serving gateway <NUM> sends a modify bearer response message to the MME <NUM>. In a thirteenth communication <NUM> from the MME <NUM> to the target eNB <NUM>, the MME <NUM> confirms the path switch request message with a path switch request acknowledge message. In a fourteenth communication <NUM> from the target eNB <NUM> to the source eNB <NUM>, by sending a UE context release message, the target eNB <NUM> informs success of the handover to the source eNB <NUM> and triggers the release of resources by the source eNB <NUM>. The target eNB <NUM> sends this message after the path switch request acknowledge message is received from the MME <NUM>. Upon reception of the UE context release message, the source eNB <NUM> may release <NUM> radio and C-plane related resources associated to the UE <NUM> context. Any ongoing data forwarding may continue.

In the communication system described in <FIG>, handover failure may occur due to the following three reasons: an RLF (e.g., too late handover) may occur after the UE <NUM> has stayed for a long period of time in a cell and the UE <NUM> may attempt to re-establish a radio link connection in a different cell; an RLF (e.g., too early handover) may occur shortly after a successful handover from a source cell to a target cell or a handover failure occurs during the handover procedure and the UE <NUM> may attempt to re-establish a radio link connection in a source cell; and an RLF (e.g., handover to a wrong cell) may occurs shortly after a successful handover from a source cell to a target cell or a handover failure may occur during a handover procedure and the UE <NUM> may attempt to re-establish the radio link connection in a cell other than a source cell and a target cell.

<FIG> illustrates one embodiment of communications <NUM> for conditional handovers. By using conditional handovers, too late handover, too early handover, and/or handover to a wrong cell may be avoided. Communications <NUM> between a UE <NUM>, a gNB <NUM>, and a target gNB <NUM> are illustrated.

A first communication <NUM> transmitted from the UE <NUM> to the source gNB <NUM> may include the UE <NUM> reporting measurement results (e.g., reference signal received power ("RSRP"), reference signal received quality ("RSRQ")) based on a trigger condition configured by the source gNB <NUM>. A second communication <NUM> from the source gNB <NUM> to the target gNB <NUM> may include, in response to the source gNB <NUM> making a decision to perform conditional handover based on the measurement result from the UE <NUM>, the source gNB <NUM> sending a handover request to the target gNB <NUM>. The handover request may be sent to more than one candidate cell (e.g., target gNBs). A third communication <NUM> from the target gNB <NUM> to the source gNB <NUM> may include the source gNB <NUM> receiving a handover acknowledge from the target gNB <NUM> (e.g., one or more candidate cells). A fourth communication <NUM> from the source gNB <NUM> to the UE <NUM> may include the source gNB <NUM> sending a RRCconnectionreconfiguration message including mobilityControlInfo IE and a condition for handover configured by the source gNB <NUM> to the UE <NUM>. Meanwhile, the source gNB <NUM> may forward data to the target gNB <NUM> (e.g., all candidate cells).

A fifth communication <NUM> from the UE <NUM> to the target gNB <NUM> may include, in response to the condition being met and the UE <NUM> applying the RRCconnectionreconfiguration, accessing the target gNB <NUM>. A sixth communication <NUM> from the UE <NUM> to the target gNB <NUM> may include the UE <NUM> informing the target gNB <NUM> that RRC reconfiguration is complete. A seventh communication <NUM> from the target gNB <NUM> to the source gNB <NUM> may include the target gNB <NUM> informing the source gNB <NUM> that handover is completed.

In certain embodiments, to avoid handover to a wrong cell and/or redundancy handover, the UE <NUM> may select a candidate cell (out of multiple available candidate cells) with a best channel quality (e.g., highest RSRP) as the target cell if more than one candidate cell meets the condition.

In some embodiments, the UE <NUM> may have a trigger condition for handover in which the trigger condition is relative to another cell such as a serving cell and/or one or more candidate cells. For example, the trigger condition for handover may be that the target cell (or beam) becomes offset better than a serving cell (or beam) and/or the target cell (or beam) becomes better than other candidate cells (or beams. As another example, the trigger condition for handover may be that the target cell (or beam) becomes offset better than the serving cell (or beam) in a configured duration and/or the target cell (or beam) becomes better than other candidate cells (or beams) in the configured duration. In some embodiments, the configured duration (e.g., predetermined time period) may be configured by a base unit <NUM>.

In various embodiments, a new behavior for a remote unit <NUM> is defined for suspended RRCConnectionReconfiguration including mobilityControlInfo and a condition for handover. For example, in one embodiment a base unit <NUM> informs a remote unit <NUM> to release a suspended RRCConnectionReconfiguration including conditional handover command by using RRC signaling.

As another example, in certain embodiments, a timer may be included in RRCConnectionReconfiguration including conditional handover. Once the timer expires, the remote unit <NUM> may release the RRCConnectionReconfiguration including conditional handover.

As a further example, in some embodiments, a remote unit <NUM> may suspend suspends RRCConnectionReconfiguration including conditional handover until a new RRCConnectionReconfiguration including conditional handover is configured. In such embodiments, in response to RRCConnectionReconfiguration including conditional handover being received by a remote unit <NUM>, the remote unit <NUM> overwrites the previous suspended RRCConnectionReconfiguration including conditional handover.

<FIG> is a schematic flow chart diagram illustrating one embodiment of a method <NUM> for conditional handovers. In some embodiments, the method <NUM> is performed by an apparatus, such as the remote unit <NUM>. In certain embodiments, the method <NUM> may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

The method <NUM> may include receiving <NUM> a handover command involving multiple candidate cells. The method <NUM> also includes selecting <NUM> a target cell of the multiple candidate cells in response to the target cell meeting a predetermined condition.

In one embodiment, selecting the target cell includes selecting the target cell with a best channel quality. In a further embodiment, selecting the target cell includes selecting the target cell with a highest reference signal received power. In certain embodiments, the predetermined condition is indicated in the handover command. In various embodiments, each candidate cell of the multiple candidate cells has a corresponding predetermined condition.

In some embodiments, the handover command is a conditional handover command. In one embodiment, the handover command is part of RRCConnectionReconfiguration and includes mobilityControlInfo. In certain embodiments, the method <NUM> includes applying the RRCConnectionReconfiguration including the handover command in response to selecting the target cell. In various embodiments, the method <NUM> includes overwriting a previously suspended handover command in response to receiving the handover command having the predetermined condition.

<FIG> is a schematic flow chart diagram illustrating a method <NUM> for conditional handovers according to the claimed embodiment. In some embodiments, the method <NUM> is performed by an apparatus, such as the remote unit <NUM>. In certain embodiments, the method <NUM> may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

The method <NUM> includes receiving <NUM> a handover command involving multiple candidate cells. The method <NUM> also includes selecting <NUM> a target cell of the multiple candidate cells in response to the target cell meeting a predetermined condition relative to other cells of the multiple candidate cells.

In the claimed embodiment embodiment, the predetermined condition includes an offset that is better than a serving cell, an offset that is better than the other cells of the multiple candidate cells, or some combination thereof. In a further embodiment, the predetermined condition includes an offset that is better than a serving cell in a predetermined time period, an offset that is better than the other cells of the multiple candidate cells in the predetermined time period, or some combination thereof. In certain embodiments, the predetermined time period is configured by a base unit. In the claimed embodiment, the predetermined condition is indicated in the handover command.

In some embodiments, each candidate cell of the multiple candidate cells has a corresponding predetermined condition. In one embodiment, the handover command is a conditional handover command. In certain embodiments, the handover command is part of RRCConnectionReconfiguration and includes mobilityControlInfo. In various embodiments, the method <NUM> includes applying the RRCConnectionReconfiguration including the handover command in response to selecting the target cell. In the claimed embodiment the method <NUM> includes overwriting a previously suspended handover command in response to receiving the handover command having the predetermined condition.

<FIG> is a schematic flow chart diagram illustrating a further embodiment of a method <NUM> for conditional handovers. In some embodiments, the method <NUM> is performed by an apparatus, such as the remote unit <NUM>. In certain embodiments, the method <NUM> may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

The method <NUM> may include receiving <NUM> RRCConnectionReconfiguration including a condition for handover. The method <NUM> also includes suspending <NUM> the RRCConnectionReconfiguration until the condition for handover is met. The method <NUM> includes overwriting <NUM> the previously suspended RRCConnectionReconfiguration including the condition for handover in response to a predetermined criteria.

In one embodiment, the predetermined criteria includes a timer that is part of the RRCConnectionReconfiguration, and in response to the timer elapsing the RRCConnectionReconfiguration is released. In a further embodiment, the timer is started in response to the receiver receiving the RRCConnectionReconfiguration. In certain embodiments, the timer is stopped in response to applying the RRCConnectionReconfiguration. In various embodiments, in response to the timer expiring, the method <NUM> includes releasing the suspended RRCConnectionReconfiguration including the condition for handover.

In some embodiments, the predetermined criteria includes receiving a new RRCConnectionReconfiguration, and in response to receiving the new RRCConnectionReconfiguration, the new RRCConnectionReconfiguration overwrites the RRCConnectionReconfiguration including the condition for handover. In one embodiment, the method <NUM> includes applying the RRCConnectionReconfiguration in response to the condition for handover being met.

Claim 1:
A method performed by a user equipment (<NUM>), the method comprising:
receiving (<NUM>) a handover command involving a plurality of candidate cells (<NUM>);
selecting (<NUM>) a target cell of the plurality of candidate cells (<NUM>) in response to the target cell meeting a predetermined condition relative to other cells of the plurality of candidate cells;
wherein the predetermined condition is indicated in the handover command and comprises the condition where the target cell becomes offset better than the serving cell and/or where the target cell becomes offset better than other candidate cells;
characterized by:
overwriting a previously suspended handover command in response to receiving the handover command having the predetermined condition.