This description relates to wireless communications.
A communication system may be a facility that enables communication between two or more nodes or devices, such as fixed or mobile communication devices. Signals can be carried on wired or wireless carriers.
An example of a cellular communication system is an architecture that is being standardized by the 3rd Generation Partnership Project (3GPP). A recent development in this field is often referred to as the long-term evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio-access technology. E-UTRA (evolved UMTS Terrestrial Radio Access) is the air interface of 3GPP's Long Term Evolution (LTE) upgrade path for mobile networks. In LTE, base stations or access points (APs), which are referred to as enhanced Node AP (eNBs), provide wireless access within a coverage area or cell. In LTE, mobile devices, or mobile stations are referred to as user equipments (UE). LTE has included a number of improvements or developments. Aspects of LTE are also continuing to improve.
5G New Radio (NR) development is part of a continued mobile broadband evolution process to meet the requirements of 5G, similar to earlier evolution of 3G & 4G wireless networks. In addition, 5G is also targeted at the new emerging use cases in addition to mobile broadband. A goal of 5G is to provide significant improvement in wireless performance, which may include new levels of data rate, latency, reliability, and security. 5G NR may also scale to efficiently connect the massive Internet of Things (IoT) and may offer new types of mission-critical services. For example, ultra-reliable and low-latency communications (URLLC) devices may require high reliability and very low latency.
According to an example embodiment, a method may include: receiving, by a first network node that is configured as a master node from a second network node that is configured as a source secondary node for dual connectivity for a user device, a message including control information indicating whether or not the first network node may receive from the second network node an updated measurement configuration based on a list of accepted target Primary Secondary Cells (PSCells) that are accepted by the target secondary node among a list of candidate target PSCells; sending, by the first network node to the user device, a conditional reconfiguration message including the initial measurement configuration that is based on the list of candidate target PSCells if the control information indicated that the first network node will not receive from the second network node an updated measurement configuration; and otherwise, sending, by the first network node to the user device, a conditional reconfiguration message including the updated measurement configuration that is based on the list of accepted target PSCells if the control information indicated that the first network node may receive from the second network node an updated measurement configuration based on the list of accepted target PSCells.
According to an example embodiment, a method may include: receiving, by a first network node that is configured as a master node from a second network node that is configured as a source secondary node for dual connectivity for a user device, a message including a list of candidate target Primary Secondary Cells (PSCells) for a target secondary node, an initial measurement configuration for the user device based on the list of candidate target PSCells including at least a conditional PSCell change (CPC) execution condition for one or more of the candidate target PSCells; receiving, from the target secondary node, a list of accepted target PSCells that are accepted by the target secondary node among the list of candidate target PSCells; comparing the list of accepted target PSCells that are accepted by the target secondary node to the list of candidate target PSCells; determining whether the list of accepted target PSCells is the same as or different from the list of candidate target PSCells; performing the following if the list of accepted target PSCells is the same as the list of candidate target PSCells: sending, by the first network node to the user device, a conditional reconfiguration message including the initial measurement configuration that is based on the list of candidate target PSCells, without waiting to receive an updated measurement configuration; otherwise, performing the following if the list of accepted target PSCells is different from the list of candidate target PSCells: waiting to receive, by the first network node from the second network node, the updated measurement configuration that is based on the list of accepted target PSCells; and sending, by the first network node to the user device, a conditional reconfiguration message including the updated measurement configuration that is based on the list of accepted target PSCells.
According to an example embodiment, a method may include: sending, by a second network node that is configured as a source secondary node to a first network node that is configured as a master node for dual connectivity for a user device, a message including a list of candidate target Primary Secondary Cells (PSCells) for a target secondary node, an initial measurement configuration for the user device based on the list of candidate target PSCells including at least a conditional PSCell change (CPC) execution condition for one or more of the candidate target PSCells, and control information indicating whether or not the first network node may receive from the second network node an updated measurement configuration based on a list of accepted target PSCells that are accepted by the target secondary node among the list of candidate target PSCells; receiving, by the second network node from the first network node, a list of accepted target PSCells that are accepted by the target secondary node among the list of candidate target PSCells; determining, by the second network node, an updated measurement configuration based on the list of accepted target PSCells that are accepted by the target secondary node, the updated measurement configuration including at least a conditional PSCell change (CPC) execution condition for one or more of the candidate target PSCells; and sending, by the second network node to the first network node, the updated measurement configuration.
According to an example embodiment, a method may include: receiving, by a user device from a first network node that is configured as a master node for dual connectivity for the user device, a conditional reconfiguration message including a list of accepted target Primary Secondary Cells (PSCells) that are accepted by a target secondary node among a list of candidate target PSCells determined by a second network node that is configured as a source secondary node for dual connectivity for the user device, an updated measurement configuration that is based on the list of accepted target PSCells, the updated measurement configuration based on the list of accepted target PSCells that are accepted by the target secondary node, the updated measurement configuration including at least a measurement object indicating an object or resources to be measured and a conditional PSCell change (CPC) execution condition for one or more of the accepted target PSCells; and determining, by the user device, that a cell, associated with a measurement gap that was previously configured by the second network node for the user device, is not on the list of accepted target PSCells; and, releasing, by the user device, a measurement gap that was previously configured by the user device that is associated with a cell and which is not on the list of accepted target PSCells.
Other example embodiments are provided or described for each of the example methods, including: means for performing any of the example methods; a non-transitory computer-readable storage medium comprising instructions stored thereon that, when executed by at least one processor, are configured to cause a computing system to perform any of the example methods; and an apparatus including at least one processor, and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform any of the example methods.
The details of one or more examples of embodiments are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.
A base station (e.g., such as BS 134) is an example of a radio access network (RAN) node within a wireless network. A BS (or a RAN node) may be or may include (or may alternatively be referred to as), e.g., an access point (AP), a gNB, an eNB, or portion thereof (such as a/centralized unit (CU) and/or a distributed unit (DU) in the case of a split BS or split gNB), or other network node.
According to an illustrative example, a BS node (e.g., BS, eNB, gNB, CU/DU, . . . ) or a radio access network (RAN) may be part of a mobile telecommunication system. A RAN (radio access network) may include one or more BSs or RAN nodes that implement a radio access technology, e.g., to allow one or more UEs to have access to a network or core network. Thus, for example, the RAN (RAN nodes, such as BSs or gNBs) may reside between one or more user devices or UEs and a core network. According to an example embodiment, each RAN node (e.g., BS, eNB, gNB, CU/DU, . . . ) or BS may provide one or more wireless communication services for one or more UEs or user devices, e.g., to allow the UEs to have wireless access to a network, via the RAN node. Each RAN node or BS may perform or provide wireless communication services, e.g., such as allowing UEs or user devices to establish a wireless connection to the RAN node, and sending data to and/or receiving data from one or more of the UEs. For example, after establishing a connection to a UE, a RAN node or network node (e.g., BS, eNB, gNB, CU/DU, . . . ) may forward data to the UE that is received from a network or the core network, and/or forward data received from the UE to the network or core network. RAN nodes or network nodes (e.g., BS, eNB, gNB, CU/DU, . . . ) may perform a wide variety of other wireless functions or services, e.g., such as broadcasting control information (e.g., such as system information or on-demand system information) to UEs, paging UEs when there is data to be delivered to the UE, assisting in handover of a UE between cells, scheduling of resources for uplink data transmission from the UE(s) and downlink data transmission to UE(s), sending control information to configure one or more UEs, and the like. These are a few examples of one or more functions that a RAN node or BS may perform.
A user device (user terminal, user equipment (UE), mobile terminal, handheld wireless device, etc.) may refer to a portable computing device that includes wireless mobile communication devices operating either with or without a subscriber identification module (SIM), including, but not limited to, the following types of devices: a mobile station (MS), a mobile phone, a cell phone, a smartphone, a personal digital assistant (PDA), a handset, a device using a wireless modem (alarm or measurement device, etc.), a laptop and/or touch screen computer, a tablet, a phablet, a game console, a notebook, a vehicle, a sensor, and a multimedia device, as examples, or any other wireless device. It should be appreciated that a user device may also be (or may include) a nearly exclusive uplink only device, of which an example is a camera or video camera loading images or video clips to a network.
In LTE (as an illustrative example), core network 150 may be referred to as Evolved Packet Core (EPC), which may include a mobility management entity (MME) which may handle or assist with mobility/handover of user devices between BSs, one or more gateways that may forward data and control signals between the BSs and packet data networks or the Internet, and other control functions or blocks. Other types of wireless networks, such as 5G (which may be referred to as New Radio (NR)) may also include a core network.
In addition, the techniques described herein may be applied to various types of user devices or data service types, or may apply to user devices that may have multiple applications running thereon that may be of different data service types. New Radio (5G) development may support a number of different applications or a number of different data service types, such as for example: machine type communications (MTC), enhanced machine type communication (eMTC), Internet of Things (IoT), and/or narrowband IoT user devices, enhanced mobile broadband (eMBB), and ultra-reliable and low-latency communications (URLLC). Many of these new 5G (NR)-related applications may require generally higher performance than previous wireless networks.
IoT may refer to an ever-growing group of objects that may have Internet or network connectivity, so that these objects may send information to and receive information from other network devices. For example, many sensor type applications or devices may monitor a physical condition or a status, and may send a report to a server or other network device, e.g., when an event occurs. Machine Type Communications (MTC, or Machine to Machine communications) may, for example, be characterized by fully automatic data generation, exchange, processing and actuation among intelligent machines, with or without intervention of humans. Enhanced mobile broadband (eMBB) may support much higher data rates than currently available in LTE.
Ultra-reliable and low-latency communications (URLLC) is a new data service type, or new usage scenario, which may be supported for New Radio (5G) systems. This enables emerging new applications and services, such as industrial automations, autonomous driving, vehicular safety, e-health services, and so on. 3GPP targets in providing connectivity with reliability corresponding to block error rate (BLER) of 10−5 and up to 1 ms U-Plane (user/data plane) latency, by way of illustrative example. Thus, for example, URLLC user devices/UEs may require a significantly lower block error rate than other types of user devices/UEs as well as low latency (with or without requirement for simultaneous high reliability). Thus, for example, a URLLC UE (or URLLC application on a UE) may require much shorter latency, as compared to a eMBB UE (or an eMBB application running on a UE).
The techniques described herein may be applied to a wide variety of wireless technologies or wireless networks, such as LTE, LTE-A, 5G (New Radio (NR)), cmWave, and/or mmWave band networks, IoT, MTC, eMTC, eMBB, URLLC, etc., or any other wireless network or wireless technology. These example networks, technologies or data service types are provided only as illustrative examples.
In dual-connectivity (or more generally referred to as multi-connectivity), a UE (or user device) may be connected to multiple base stations or network nodes simultaneously, where the network nodes may be of the same or different radio access technologies (RATs). Thus, for multi-connectivity, each of the network nodes may be an eNB, gNB, or other network node. For example, one of the network nodes may be referred to as a master node (MN) or master network node (e.g., master gNB (MgNB) or master eNB (MeNB)), while another network node may be referred to as a secondary node (SN) or a secondary network node (e.g., a secondary gNB (SgNB) or secondary eNB (SeNB)), e.g, with respect to the classical BS architecture. For dual or multi-connectivity, the UE may, for example, establish a first connection to a MN, and then establish a second connection to a SN. For each of the network nodes (MN or SN) that the UE is connected to, the UE may be able to communicate and/or receive data via multiple (a plurality of) cells, e.g., using carrier aggregation (CA). The cells of the MN may be referred to as a master cell group (MCG), while the cells of a SN may be referred to as a secondary cell group (SCG).
In the case of dual or multi-connectivity, the first cell (of the master cell group (MCG)) within the MN to which the UE connects is typically known as the Primary Cell (PCell), while the first cell (of the secondary cell group (SCG)) within the SN to which the UE connects is typically known as the Primary Secondary Cell (PSCell), which serves as a primary cell as far as the UE's connectivity to the SN is concerned. The PCell and the PSCell are each allocated physical uplink control channel (PUCCH) resources to allow the UE to send HARQ ACK/NAK (acknowledgement/negative acknowledgement) feedback, and other control information, to the MCG (or MN) and SCG (or SN), respectively.
Handover (HO) (or cell change) procedures may be used in 5G NR to allow a
change or handover of the UE from a source network node to a target network node, e.g., to maintain robustness of connection between a user equipment (UE) and a wireless network over different cells. A UE handover (HO) may be performed for a UE for both MN and SN, e.g., based on measurement reports and/or a HO trigger condition being satisfied.
For example, with respect to a UE connected to only one network node (single connectivity, or with respect to a MN HO for dual connectivity for the UE), to effect a HO, a UE sends measurement reports to a source network node indicating measurement values for serving and neighboring cells such as reference signal received power (RSRP). The measurement report is typically sent in an event-triggered manner when the measurement values meet certain criteria (e.g., the RSRP of neighboring cell becomes better than the measurement of the serving cell by some offset for some Time-to-Trigger (TTT)). Upon receiving the measurement report, the source network node (e.g., source gNB) identifies a target network node (a target gNB) to which the source gNB sends a HO request. The target gNB may acknowledge the HO request by sending an acknowledgement message to the source gNB. In response, the source gNB then sends a radio resource control (RRC) reconfiguration message to the UE, indicating a HO to the target gNB; at this point, data exchange between the UE and the source gNB terminates and the source gNB forwards data intended for the UE to the target gNB. The UE then initiates communication with the target gNB. For example, the UE sends a physical random access channel (PRACH) preamble to the target gNB. In response, the target gNB sends the UE a random access response (RAR), and the UE sends to the target gNB a message indicating that the RRC reconfiguration is complete. The target gNB sends the forwarded data to the UE and the connection between the UE and target gNB is established.
Alternatively, conditional HO (CHO) has been introduced to reduce radio link and HO failures. In CHO, a configured event triggers the UE to send a measurement report. Based on this report, the source gNB can prepare one or more target cells for the handover (CHO Request+CHO Request Acknowledge) and then sends an RRC Reconfiguration (including handover command) to the UE. In the baseline HO described above, the UE will immediately access the target cell to complete the handover. In contrast, for CHO, the UE will only access the target cell once an additional CHO execution condition is met (the handover preparation and execution phases are decoupled). The CHO execution condition may be configured, e.g., by the source network node in RRC Reconfiguration.
For a UE configured for dual connectivity (where the UE is connected to both a master node (MN) and a secondary node (SN)), with respect to the MN, a conditional handover may be prepared for the MN to allow the UE to perform a conditional handover from a source MN to a target MN when the CHO execution condition is met. Likewise, with respect to the SN, a Conditional PSCell Change (CPC) may be configured to allow the UE to perform a conditional handover or conditional PSCell change from a source SN to a target SN when the CHO/CPC execution condition is met for the target SN.
In step 1, the source SN 214 indicates to MN 212 the identities or identifiers (IDs) of the target SNs that should be contacted for preparing target PSCell(s). Thus, at step 1, source SN 214 may send to MN 212 a SN/SgNB change required message, which may include IDs of the target SNs, and a list of candidate target Primary Secondary Cells (PSCells) for each indicated target SN, and a measurement configuration for the UE. The measurement configuration for the UE is determined (or configured) by the source SN 214 based on the list of candidate target PSCells, and may include the list of candidate target PSCells and an execution condition (e.g., a conditional PSCell change (CPC) execution condition) for each of or one or more of the candidate target PSCells. The measurement configuration for the UE may also include information indicating a measurement object for each candidate cell, e.g., indicating time-frequency resources or indicating reference signals to be measured by the UE 210. Thus, a measurement configuration may indicate frequencies or carrier(s) of cells of the list of candidate target PSCells to be measured by the UE 210. The measurement configuration may be relayed or forwarded by MN 212 to UE 210 via message at step 8.
In step 2/3, MN 212 may send to target SN 216 a SN addition request (at step 2) including the list of candidate target PSCells configured or indicated by the source SN 214 for target SN 216.
In step 4/5, the target SN 216 selects one or more of the candidate target PSCell(s) to accept and prepare for potential CPC. The target SN 216 may accept one or more, or even all, of the cells of the list of candidate target PSCells. Target SN 216 accepting/preparing a cell, among cells on the list of candidate target PSCells, may include, for example, allocating resources, such as a signaling radio bearer (SRB) configuration, a random access procedure (RACH) preamble, and/or other preparations for the accepted cell, to allow for a possible CPC, by UE 210, for that accepted cell. For example, a target cell (or CPC) configuration may be used by UE 210 at step 15 to access the target cell via RACH procedure in response to the execution condition (CPC condition, at steps 11 and 12) for such target cell being met.
In step 6/7, the target SN 216 sends to MN 212 a SN addition request acknowledge message that includes the CPC configuration (target cell configuration) for each accepted (e.g., prepared) target PSCell of the list of accepted target PSCell(s), among the list of candidate target PSCells. The SN addition request acknowledge at step 6 may include IDs/identifiers of the list of accepted (prepared) target PSCells. As noted, the CPC configuration (or target cell configuration) for each accepted target PSCell may include configuration or resources that may be used by the UE 210 to access the accepted target PSCell at step 15, after the execution condition (CPC condition) for such accepted target PSCell is met. As noted, the CPC configuration (target cell configuration) for an accepted target PSCell may include an SRB configuration (for a SRB configured for the UE for that cell), an indication of a RACH preamble that may be used for RACH access at step 15 by the UE 210, time-frequency resources, etc., or other target cell configuration.
In step 8, the MN 212 sends to UE 210 a conditional (re-)configuration message including: the measurement configuration (e.g., which may include the list of the candidate target PSCell to be measured, and the CPC execution conditions and measurement objects or indication of resources or reference signals to be measured for each cell of the list of candidate target PSCells) for the UE, which is determined by the source SN 214 based on the list of candidate target PSCells; and the target cell configurations (CPC configurations) of the list of accepted target PSCell(s) that is determined by the target SN 216 based on the list of accepted target PSCells.
In step 9, the UE sends a message to MN confirming the reception of the conditional configuration message at step 8, and MN 212 confirms (at step 11) to source SN 214 the SN change preparation in step 10.
In step 11, the UE 210 evaluates the CPC (or target cell) execution conditions of the accepted (prepared) target PSCell(s) for target SN 216.
In step 12, UE 210 determines that the CPC (or target cell) execution condition is met for one of the candidate target PSCells for (or provided by or in) target SN 216.
In step 13, UE 210 sends a message to MN 212 indicating the execution of the CPC configuration. The message includes an embedded SN RRC Reconfiguration Complete to the target SN 216 which is sent in step 14.
At step 15, based on the CPC execution condition being met for one of the accepted target PSCells, UE 210 completes (or performs) the random access to the target cell of target SN 216, based on the CPC (or target cell) configuration for this target cell.
With reference to
However, in some cases, one or more problems or inefficiencies may arise as part of this process shown in
Various example embodiments and/or alternatives are described that may, at least in some cases, improve efficiency of this process of PSCell reconfiguration at the UE.
In an illustrative example, MN 212 may receive a message (e.g., at step 1,
In Alternative-1 (Alt-1), Alt-2 and Alt-3, at step 1, source SN 214 sends a SN change required message to MN 212, which may include the identities or identifiers (IDs) of the target SNs that should be contacted for preparing target PSCell(s). Thus, at step 1 of
The SN change required message (at step 1,
In Alt-1, the control information (or flag) of message of step 1 indicates that the MN 212 may receive from the source SN 214 (at step 10,
For Alt-2, the MN 212 may determine that it will not receive an updated measurement configuration at step 10, based on either: 1) the flag (control information) of message of step 1 indicating that MN 212 will not receive (or that it should not expect to receive) from the source SN 214 an updated measurement configuration; or 2) the comparison performed by MN 212 at step 8 indicates that the list of accepted target PSCells (accepted by the target SN 216) is the same as the list of candidate target PSCells (indicated to MN 212 via message at step 1,
Steps 2-7 of
In Alt-1, after reporting the list of accepted target PSCells to source SN 214 at step 9, MN 212 receives (and/or waits to receive, at step 10) an updated measurement configuration based on the accepted target PSCells. In Alt-1, MN 212 may send to UE 210, at step 12, a conditional reconfiguration message (e.g., a conditional PSCell reconfiguration message) including the updated measurement configuration that is based on the list of accepted target PSCells and PSCell configurations for each of the accepted target PSCells.
In Alt-2, after reporting the list of accepted target PSCells to source SN 214 at step 9, MN 212 does not receive (and/or does not wait to receive, at step 10) an updated measurement configuration based on the accepted target PSCells. In Alt-2, MN 212 may send to UE 210, at step 12, a conditional reconfiguration message (e.g., a conditional PSCell reconfiguration message) including the initial measurement configuration that is based on the list of candidate target PSCells and PSCell configurations for each of the candidate target PSCells.
Thus, in Alt-2, an updated measurement configuration is not obtained by MN 212 (step 10 may be skipped by MN 212), nor provided to the UE 210 at step 12, but rather, the initial measurement configuration (obtained by MN 212 via step 1) is sent to the UE 210 at step 12 (e.g., along with a list of the candidate target PSCells and the CPC configuration for each cell of the list of candidate target PSCells).
Whereas for Alt-1, an updated measurement configuration is obtained by MN 212 at step 10, and is sent or provided to the UE 210 at step 12 (e.g., along with a list of the accepted target PSCells and the CPC configuration for each cell of the list of accepted target PSCells). At step 10, the updated measurement configuration may be, or may be considered, or may include, a measurement gap update, since accepted target PSCells are indicated (and these accepted may or may not be inter-frequency, or have reference signals on same or different carrier/carrier frequencies, which thus may or may not require a measurement gap). UE 210 may determine such measurement gap update based on the accepted target PSCells, and whether any of the accepted target PSCells are inter-frequency cells (or provided on different carriers or frequencies, that would require a measurement gap for the UE to switch or tune its receiver to the different frequency for reference signal measurement).
Steps 14-20 may be the same as or similar to the steps 9-15 of
In another example embodiment, the SN change required message at step 1 may include a list of cells (a list of target PSCells) requiring an updated measurement configuration. After receiving the list of accepted target PSCells at step 6, the MN 212 may determine if the list of accepted cells includes any cells that were indicated in message at step 1 that require an updated measurement configuration, the MN 212 obtains an updated measurement configuration at 10, and then sends this updated measurement configuration to the UE 210 at step 12.
In another example embodiment, in general, a measurement gap may be released or added by a UE, based on the (carriers or frequencies of reference signals for the) accepted target PSCells, for example. For example, if inter-frequency cells are not included in the list of accepted target PSCells, then a measurement gap that is associated with an inter-frequency cell that has been omitted from the accepted target PSCells, may be released by the UE 210. Or, if the list of accepted target PSCells includes inter-frequency cells (target PSCells on different carriers or frequencies), then the UE may add a measurement gap to allow the UE to perform measurement for the cells of the list of accepted target PSCells.
For Alt-3, the message at step 1 may include a list of cells with autonomous measurement gap removal is allowed by the UE. This list of cells with autonomous measurement gap removal allowed, may be forwarded to the UE from MN 212 via message at 12. The UE 210 may then determine if one of these cells was omitted from the received measurement configuration (e.g., updated measurement configuration). The UE 210 may, for example, release (remove or omit) the measurement gap of a cell on this list, if such cell is not on the list of cells (e.g., accepted cells) of the received measurement configuration, and the information in message of step 1 indicates that the UE 210 may remove such measurement gap. Thus, efficiency may be improved by allowing the UE to release or remove a measurement gap for an inter-frequency cell that is omitted from (or not included within) the measurement configuration (e.g., updated measurement configuration) and/or list of cells (e.g., list of accepted target PSCells) received by UE 210 via step 12.
Some further examples or details are provided below.
For example a Source SN may inform the MN in Step 1: SN Change Required, indicating whether or not the MN shall wait for the response (in step 10) from the source SN upon receiving the information on which target PSCells have been prepared (the list of accepted target PSCells, via message at step 9):
If the source SN has indicated in Step 1: SN Change Required that no such response (no updated measurement configuration at step 10) should be expected, the MN informs the source SN of which cells have been accepted/prepared and then proceeds directly to step 12 to send the CPC command (RRC Reconfiguration message towards the UE, comprising measurement configuration (including CPC execution conditions) and Target PSCell configurations).
If the source SN has indicated in Step 1: SN Change Required that such measurement reconfiguration may be required (and thus an indication that the MN should receive or wait to receive at step 10, the updated measurement configuration) that an updated measurement configuration (e.g., in case target SN accepts the inter-frequency candidate PSCell, which may require to provide the UE with a measurement gap), then the MN sends (at step 9) the notification on which cells were accepted/prepared to source SN and waits for the response which may include a reconfiguration of SN's configuration at the UE (to be provided via MN). Alternatively, this may also be provided to the UE via SRB3, directly from the SN, if SRB3 is supported).
The source SN can also inform in Step 1: SN Change Required as to which particular cells requires the update of the measurement configuration, so MN shall wait for source SN's reaction (at step 10) to the list of accepted cells, e.g., MN should wait to receive updated measurement configuration, based on list of accepted target PSCells.
Alternative method (denoted by Alt-3): UE autonomous gap disabling/releasing as part of CPAC or CPC evaluation. Source SN can inform in Step 1 autonomous gap disabling/releasing at UE based on the applicable cells as part of CPC evaluation. In this case source SN decides to activate the measurement gap based on the list of cells indicated from MN after CPC preparation, e.g., UE may activate a measurement gap if inter-frequency cells are included on list of accepted target PSCells and the UE has permission to adjust (add or release) the measurement gap.
For example, the UE may determine or decide to use measurement gap only if at least one of the applicable (listed) cells (accepted target PSCells) are inter-frequency cell. In the same way source SN may also decide to activate a measurement gap only if there is one inter-frequency candidate cell prepared.
1st example, wherein SN has intra-frequency neighbours: cells c1, c2:
In this example, measurement gaps are not configured at all in the measurement configuration since the measurement object configured by SN is for the same frequency. In this case, after the first measurement report is sent by the UE to the source SN the preparations for, e.g., cell c1 (and/or cell c2) start. Source SN indicates to MN that there is no need to wait for the response (at step 10) from source SN after informing source SN about the list of prepared cells (at step 9).
2nd example, wherein SN has inter-frequency neighbours, cells c1, c2:
In this example, measurement gaps are configured in the measurement configuration since the measurement object configured by SN is for different frequency. After the first measurement report is triggered for cell, e.g. c1 (and/or c2), source SN triggers CPC preparation for cell c1 (and/or cell c2). Source SN indicates to MN that there is no need to wait (at step 10) for the response from source SN after informing SN about the list of prepared cells. This is because the source SN has already configured measurement gaps which are needed to measure both cells c1 and c2.
3rd example, wherein SN has intra-frequency neighbours, cells c1, c2 and inter-frequency neighbours, cells c3, c4:
In this example, measurements gaps are configured for measuring inter-frequency cells, i.e., c3 and c4. When the first measurement report is received by source SN (which serves as a basis for triggering the CPC preparations), e.g., cells c2 and c3 are selected by the source SN to be prepared from the target SN. The decision concerning the future use of measurement gaps depends on which of those will be finally accepted and prepared by target SN. If c3 is prepared by target SN, then the measurement gap is needed. But as it was configured beforehand, no need for the SN to take subsequent actions and update the measurement configuration. If c3 is not prepared by target SN, then the measurement gap can be released. Herein, MN informs the source SN about the list of prepared PSCells and S-SN reconfigures its measurement configuration (also referred to as the updated measurement configuration) which is provided to the UE along with the conditional reconfiguration. The MN may send such notification and wait for S-SN's response before contacting the UE, based on the list of cells (received in Step 1: SN Change Required) which-in case any cell is accepted that require further reconfiguration from the source SN.
In one embodiment, the MN updates the source SN (irrespective of the prepared target PSCells) as shown in step 9 and waits for a response from the source SN (see Alt-1 in step 10) before sending the conditional reconfiguration to the UE if the flag value set by source SN (in Step 1) was V1 (value 1). Herein, the MN does not need to perform the check (comparison) of step 8.
In another embodiment, the MN updates the source SN in step 9 and waits for a response from the source SN (at step 10) before sending the conditional reconfiguration to the UE (see Alt-1 in step 10) only if the target SN prepared at least one PSCell that is part of the “list of cells requiring update” provided by source SN to MN in Step 1 of
In another embodiment, the MN sends immediately the conditional reconfiguration to the UE (irrespective of the prepared target PSCells) without waiting for a response from the source SN (i.e., without step 10 of
In yet another embodiment, the MN informs the S-SN on which cells have been prepared and sends directly the Conditional Reconfiguration to the UE without waiting for a response from the source SN (i.e. without Step 10). In Step 1 of
An updated measurement configuration may be obtained and forwarded to the UE, to improve efficiency, by allowing release of measurement gaps and signal measurement only for indicated target PSCells, for example. Also, for example, the measurement configuration may be updated only when it is needed, reducing the signaling overhead, latency and unnecessary measurement gap configurations. Also, a UE may be allowed to adjust measurement gap(s), e.g., add or release a measurement gap, e.g., based on control signals indicating permission to make such change to measurement gap(s) and/or based on the list of target PSCells or measurement configuration provided to the UE.
Example 1.
Example 2. The method of example 1 wherein the message comprises a secondary node change required message.
Example 3. The method of example 1, wherein: the receiving comprises receiving, by a first network node that is configured as a master node from a second network node that is configured as a source secondary node for dual connectivity for a user device, a message including a list of candidate target Primary Secondary Cells (PSCells) for a target secondary node, an initial measurement configuration for the user device based on the list of candidate target PSCells including at least a conditional PSCell change (CPC) execution condition for one or more of the candidate target PSCells, and control information indicating whether or not the first network node may receive from the second network node an updated measurement configuration based on a list of accepted target PSCells that are accepted by the target secondary node among the list of candidate target PSCells; wherein the sending comprises sending, by the first network node to the user device without waiting to receive the updated measurement configuration, a conditional reconfiguration message including the initial measurement configuration that is based on the list of candidate target PSCells if the control information indicated that the first network node will not receive from the second network node an updated measurement configuration; and wherein the otherwise sending comprises: otherwise, performing the following if the control information indicated that the first network node may receive from the second network node an updated measurement configuration based on the list of accepted target PSCells: receiving, by the first network node from the second network node, the updated measurement configuration that is based on the list of accepted target PSCells; and sending, by the first network node to the user device, a conditional reconfiguration message including the updated measurement configuration that is based on the list of accepted target PSCells.
Example 4. The method of example 2, further comprising: sending, by the first network node to the second network node, the list of accepted target PSCells; wherein the receiving, by the first network node from the second network node, the updated measurement configuration is based on the list of accepted target cells sent to the second network node.
Example 5. The method of any of examples 1-4: wherein the message further comprises a request to provide a list of accepted target PSCells that are accepted by the target secondary node among the list of candidate target PSCells; and wherein the method further comprises: sending, by the first network node to the target secondary node, a secondary node addition request message that includes the list of candidate PSCells for the target secondary node.
Example 6. The method of any of examples 1-5 wherein the sending a conditional reconfiguration message including the initial measurement configuration comprises: sending, by the first network node to the user device, a conditional reconfiguration message including the initial measurement configuration that is based on the list of candidate target PSCells and PSCell configurations for each of the candidate target PSCells, if the control information in the received message indicated that the first network node will not receive from the second network node an updated measurement configuration.
Example 7. The method of any of examples 1-6, wherein the sending, by the first network node to the user device, a conditional reconfiguration message including the updated measurement configuration comprises: sending, by the first network node to the user device, a conditional reconfiguration message including the updated measurement configuration that is based on the list of accepted target PSCells and PSCell configurations for each of the accepted target PSCells, if the control information in the received message indicated that the first network node may receive from the second network node an updated measurement configuration.
Example 8. The method of any of examples 1-2, further comprising: receiving, from the target secondary node, the list of accepted target PSCells that are accepted by the target secondary node among the list of candidate target PSCells; sending, by the first network node to the second network node, the list of accepted target PSCells; wherein the otherwise performing the following if the control information indicated that the first network node may receive from the second network node an updated measurement configuration comprises performing the following: comparing the list of accepted target PSCells that are accepted by the target secondary node to the list of candidate target PSCells; determining whether the list of accepted target PSCells are the same as or different from the list of candidate target PSCells; performing the following if the list of accepted target PSCells is the same as the list of candidate target PSCells: sending, by the first network node to the user device, a conditional reconfiguration message including the initial measurement configuration that is based on the list of candidate target PSCells; otherwise, performing the following if the list of accepted target PSCells is different from the list of candidate target PSCells: receiving, by the first network node from the second network node, the updated measurement configuration that is based on the list of accepted target PSCells; sending, by the first network node to the user device, a conditional reconfiguration message including the updated measurement configuration that is based on the list of accepted target PSCells.
Example 9. The method of any of examples 1-3: wherein the message further comprises a list of cells among the list of candidate target PSCells cells that require an updated measurement configuration; the method further comprising: receiving, by the first network node from the second network node, the updated measurement configuration that is based on the list of accepted target PSCells; determining that one or more cells that require an updated measurement configuration are on the list of accepted target PSCells; and sending, by the first network node to the user device, a conditional reconfiguration message including the updated measurement configuration, in response to determining that one or more cells that require an updated measurement configuration are on the list of accepted target PSCells.
Example 10. The method of example 1: wherein the message further comprises an indication that the user device may release a measurement gap if the list of accepted target PSCells does not include an inter-frequency cell associated with the measurement gap; wherein the conditional reconfiguration message further includes the indication that the user device may release a measurement gap if the list of accepted target PSCells does not include an inter-frequency cell associated with the measurement gap.
Example 11. A non-transitory computer-readable storage medium comprising instructions stored thereon that, when executed by at least one processor, are configured to cause a computing system to perform the method of any of examples 1-10.
Example 12. An apparatus comprising means for performing the method of any of examples 1-10.
Example 13. An apparatus comprising: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform the method of any of examples 1-10.
Example 14.
Example 15. The method of example 14, further comprising: sending, by the first network node to the second network node, the list of accepted target PSCells; wherein the receiving, by the first network node from the second network node, the updated measurement configuration is based on the list of accepted target cells sent to the second network node.
Example 16. The method of any of examples 14-15: wherein the message further comprises a request to provide a list of accepted target PSCells that are accepted by the target secondary node among the list of candidate target PSCells; and wherein the method further comprises: sending, by the first network node to the target secondary node, a secondary node addition request message that includes the list of candidate PSCells for the target secondary node.
Example 17. The method of any of examples 14-16 wherein the sending a conditional reconfiguration message including the initial measurement configuration comprises: sending, by the first network node to the user device, a conditional reconfiguration message including the initial measurement configuration that is based on the list of candidate target PSCells and PSCell configurations for each of the candidate target PSCells.
Example 18. The method of any of examples 14-17, wherein the sending, by the first network node to the user device, a conditional reconfiguration message including the updated measurement configuration comprises: sending, by the first network node to the user device, a conditional reconfiguration message including the updated measurement configuration that is based on the list of accepted target PSCells and PSCell configurations for each of the accepted target PSCells.
Example 19. The method of example 14: wherein the message further comprises an indication that the user device may release a measurement gap if the list of accepted target PSCells do not include an inter-frequency cell associated with the measurement gap; wherein the sending, by the first network node to the user device, a conditional reconfiguration message including the updated measurement configuration comprises: sending, by the first network node to the user device, a conditional reconfiguration message including the updated measurement configuration that is based on the list of accepted target PSCells, PSCell configurations for each of the accepted target PSCells, and the indication that the user device may release a measurement gap if the list of accepted target PSCells does not include an inter-frequency cell associated with the measurement gap.
Example 20. A non-transitory computer-readable storage medium comprising instructions stored thereon that, when executed by at least one processor, are configured to cause a computing system to perform the method of any of examples 14-19.
Example 21. An apparatus comprising means for performing the method of any of examples 14-19.
Example 22. An apparatus comprising: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform the method of any of examples 14-19.
Example 23.
Example 24. The method of example 23, wherein the message comprises a secondary node change required message.
Example 25.
Example 26. The method of example 25, further comprising: performing, by the user device, measurement of signals associated with one or more cells of the list of accepted target PSCells, while omitting measurement of the cell associated with the released measurement gap.
Example 27. The method of any of examples 25-26, wherein the conditional reconfiguration message includes an indication that the user device may release a measurement gap if the list of accepted target PSCells does not include an inter-frequency cell associated with the measurement gap; wherein the releasing is performed based on the indication that the user device may release the measurement gap.
Example 28. The method of example 25: wherein the conditional reconfiguration message further includes an indication that the user device may release a measurement gap if the list of accepted target PSCells does not include an inter-frequency cell associated with the measurement gap.
Example 29. The method of example 25: wherein the conditional reconfiguration message further comprises the updated measurement configuration that is based on the list of accepted target PSCells, PSCell configurations for each of the accepted target PSCells, and an indication that the user device may release a measurement gap if the list of accepted target PSCells does not include an inter-frequency cell associated with the measurement gap.
Example 30. A non-transitory computer-readable storage medium comprising instructions stored thereon that, when executed by at least one processor, are configured to cause a computing system to perform the method of any of examples 25-29.
Example 31. An apparatus comprising means for performing the method of any of examples 25-29.
Example 32. An apparatus comprising: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform the method of any of examples 25-29.
Processor 1204 may also make decisions or determinations, generate frames, packets or messages for transmission, decode received frames or messages for further processing, and other tasks or functions described herein. Processor 1204, which may be a baseband processor, for example, may generate messages, packets, frames or other signals for transmission via wireless transceiver 1202 (1202A or 1202B). Processor 1204 may control transmission of signals or messages over a wireless network, and may control the reception of signals or messages, etc., via a wireless network (e.g., after being down-converted by wireless transceiver 1202, for example). Processor 1204 may be programmable and capable of executing software or other instructions stored in memory or on other computer media to perform the various tasks and functions described above, such as one or more of the tasks or methods described above. Processor 1204 may be (or may include), for example, hardware, programmable logic, a programmable processor that executes software or firmware, and/or any combination of these. Using other terminology, processor 1204 and transceiver 1202 together may be considered as a wireless transmitter/receiver system, for example.
In addition, referring to
In addition, a storage medium may be provided that includes stored instructions, which when executed by a controller or processor may result in the processor 1204, or other controller or processor, performing one or more of the functions or tasks described above.
According to another example embodiment, RF or wireless transceiver(s) 1202A/1202B may receive signals or data and/or transmit or send signals or data. Processor 1204 (and possibly transceivers 1202A/1202B) may control the RF or wireless transceiver 1202A or 1202B to receive, send, broadcast or transmit signals or data.
The embodiments are not, however, restricted to the system that is given as an example, but a person skilled in the art may apply the solution to other communication systems. Another example of a suitable communications system is the 5G concept. It is assumed that network architecture in 5G may be similar to that of LTE-advanced. 5G is likely to use multiple input-multiple output (MIMO) antennas, many more base stations or nodes than LTE (a so-called small cell concept), including macro sites operating in co-operation with smaller stations and perhaps also employing a variety of radio technologies for better coverage and enhanced data rates.
It should be appreciated that future networks will most probably utilise network functions virtualization (NFV) which is a network architecture concept that proposes virtualizing network node functions into “building blocks” or entities that may be operationally connected or linked together to provide services. A virtualized network function (VNF) may comprise one or more virtual machines running computer program codes using standard or general type servers instead of customized hardware. Cloud computing or data storage may also be utilized. In radio communications this may mean node operations may be carried out, at least partly, in a server, host or node may be operationally coupled to a remote radio head. It is also possible that node operations will be distributed among a plurality of servers, nodes or hosts. It should also be understood that the distribution of labour between core network operations and base station operations may differ from that of the LTE or even be non-existent.
Embodiments of the various techniques described herein may be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations of them. Embodiments may be implemented as a computer program product, i.e., a computer program tangibly embodied in an information carrier, e.g., in a machine readable storage device or in a propagated signal, for execution by, or to control the operation of, a data processing apparatus, e.g., a programmable processor, a computer, or multiple computers. Embodiments may also be provided on a computer readable medium or computer readable storage medium, which may be a non-transitory medium. Embodiments of the various techniques may also include embodiments provided via transitory signals or media, and/or programs and/or software embodiments that are downloadable via the Internet or other network(s), either wired networks and/or wireless networks. In addition, embodiments may be provided via machine type communications (MTC), and also via an Internet of Things (IOT).
The computer program may be in source code form, object code form, or in some intermediate form, and it may be stored in some sort of carrier, distribution medium, or computer readable medium, which may be any entity or device capable of carrying the program. Such carriers include a record medium, computer memory, read-only memory, photoelectrical and/or electrical carrier signal, telecommunications signal, and software distribution package, for example. Depending on the processing power needed, the computer program may be executed in a single electronic digital computer or it may be distributed amongst a number of computers.
Furthermore, embodiments of the various techniques described herein may use a cyber-physical system (CPS) (a system of collaborating computational elements controlling physical entities). CPS may enable the embodiment and exploitation of massive amounts of interconnected ICT devices (sensors, actuators, processors microcontrollers, . . . ) embedded in physical objects at different locations. Mobile cyber physical systems, in which the physical system in question has inherent mobility, are a subcategory of cyber-physical systems. Examples of mobile physical systems include mobile robotics and electronics transported by humans or animals. The rise in popularity of smartphones has increased interest in the area of mobile cyber-physical systems. Therefore, various embodiments of techniques described herein may be provided via one or more of these technologies.
A computer program, such as the computer program(s) described above, can be written in any form of programming language, including compiled or interpreted languages, and can be deployed in any form, including as a standalone program or as a module, component, subroutine, or other unit or part of it suitable for use in a computing environment. A computer program can be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a communication network.
Method steps may be performed by one or more programmable processors executing a computer program or computer program portions to perform functions by operating on input data and generating output. Method steps also may be performed by, and an apparatus may be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).
Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer, chip or chipset. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. Elements of a computer may include at least one processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer also may include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magnetooptical disks, or optical disks. Information carriers suitable for embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magnetooptical disks; and CDROM and DVD-ROM disks. The processor and the memory may be supplemented by, or incorporated in, special purpose logic circuitry.
To provide for interaction with a user, embodiments may be implemented on a computer having a display device, e.g., a cathode ray tube (CRT) or liquid crystal display (LCD) monitor, for displaying information to the user and a user interface, such as a keyboard and a pointing device, e.g., a mouse or a trackball, by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input.
Embodiments may be implemented in a computing system that includes a backend component, e.g., as a data server, or that includes a middleware component, e.g., an application server, or that includes a frontend component, e.g., a client computer having a graphical user interface or a Web browser through which a user can interact with an embodiment, or any combination of such backend, middleware, or frontend components. Components may be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include a local area network (LAN) and a wide area network (WAN), e.g., the Internet.
While certain features of the described embodiments have been illustrated as described herein, many modifications, substitutions, changes and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the various embodiments.
Number | Date | Country | Kind |
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202141035564 | Aug 2021 | IN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2022/070724 | 7/25/2022 | WO |