Providing and using implicit PSCells

Abstract

A UE in a wireless network determines whether it has been configured with (multiple) carriers to be used for secondary serving cell carriers in the wireless network. The UE uses a selected one of the (multiple) carriers as the selected secondary serving cell carrier to perform a request for a cell on the selected secondary serving cell carrier to become a secondary serving cell for the user equipment. The UE receives a response from the cell regarding the success of the request to make the cell a secondary serving cell for the user equipment. The cell in the wireless network receives a request to make the cell a secondary cell for the user equipment on the carrier. The cell indicates to the UE that the request to make the cell a secondary cell for the user equipment is successful.

Description

Technical Field

[0001] The present invention generally relates to carrier aggregation and dual connectivity in wireless networks, and more particularly to primary secondary cell (PSCell) interaction in these wireless networks. Background Art

[0002] Abbreviations that may be found in the specification and / or drawings are defined below at the beginning of the Detailed Description section.

[0003] Carrier aggregation (CA) allows wireless (e.g., cellular) network operators to combine resources from multiple individual carriers (e.g., each with different cells). Dual connectivity (DC) is an improvement on this concept and allows a user equipment (UE) to transmit and receive data from two cell groups simultaneously on multiple component carriers via a primary cell (PCell) and potentially one or more secondary cells (SCells) in a primary cell group (MCG), and a secondary cell group (SCG) with a primary secondary cell (PSCell) and potentially one or more secondary cells (SCells). In an SCG there is one primary Scell ​​(PSCell) and (possibly) one or more other SCells, and the PCell and possibly one or other SCells are part of a primary cell group (MCG).

[0004] In the context of CA / DC or any other dual connectivity form (e.g. MR-DC, such as EN-DC, NN-DC, etc.), the concept of PCell represents the mobility anchor cell. In other words, this is the cell responsible for the Radio Resource Control (RRC) connection (establishment / reestablishment / handover (HO)). While in the context of CA, there are SCells (secondary cells) for data offloading, in the context of dual connectivity / multiple connectivity, there is at least one SCG configured with uplink (UL) component carriers (CCs) and one of them (called PSCell) is configured with physical uplink control channel (PUCCH) resources (see 3GPP TS 36.300 and 3GPP TS 38.300 for additional information).

[0005] In Long Term Evolution (LTE), it has been shown that the increased latency associated with configuring and activating SCells has a significant impact on system performance when CA is used. For this reason, a work item (WI) has been created in 3GPP (3rd Generation Partnership Project) to address how to reduce the overall latency associated with CA when configuring and activating SCells to improve overall system performance when CA is used.

[0006] During this work, called Enhanced Utilization of CA (euCA), a number of solutions were defined:

[0007] 1) Early UE measurement reporting;

[0008] 2) Direct SCell activation (e.g., direct SCell configuration and activation during handover (HO));

[0009] 3) Sleeping SCells; and

[0010] 4) Add channel state information (CSI) reporting.

[0011] In New Radio (NR), also known as 5G (fifth generation), groups are currently investigating similar WIs related to dual connectivity and carrier aggregation (DC / CA) enhancements. The focus is on reducing CA and DC setup latency to improve overall system performance. Among these solutions, LTE solutions will be assumed as the baseline - but other additional solutions also need to be considered.

[0012] The NR system design differs from LTE in several aspects, some of which affect possible solutions for reducing DC and CA establishment latency. In a broader context, a similar approach can be envisioned for any multi-connectivity approach (EN-DC, NE-DC, etc.) as part of 5G or future releases. For example, the NR physical layer only provides non-continuous synchronization signals in most cases (whereas in LTE, these signals are continuously transmitted by the network). In addition, NR includes frequencies in a higher frequency range (FR2) relative to frequency range 1 (FR1), which is typically below 6 GHz, where it is assumed that both the base station (gNB) and the UE will use transmit (Tx) and receive (Rx) beams.

[0013] This leads to the possible problem of determining how long a reporting cell can be considered valid. Summary of the invention

[0014] This section is intended to include examples and is not intended to be limiting.

[0015] In an exemplary embodiment, a method is disclosed, the method including determining, by a user equipment in a wireless network, that the user equipment has been configured with one or more carriers, the one or more carriers to be used as secondary serving cell carriers in the wireless network. The method includes, by the user equipment, using a selected one of the one or more carriers as the selected secondary serving cell carrier, executing a request for a cell on the selected secondary serving cell carrier to become a secondary serving cell for the user equipment. The method also includes receiving, by the user equipment, a response from the cell regarding a successful request to make the cell become a secondary serving cell for the user equipment.

[0016] Additional exemplary embodiments include a computer program including code for performing the method described in the previous paragraph when the computer program is run on a processor. According to the computer program of this paragraph, wherein the computer program is a computer program product including a computer readable medium, the computer readable medium carrying computer program code, the computer program code being implemented in the computer readable medium and for use with a computer. Another example is a computer program according to this paragraph, wherein the program can be directly loaded into the internal memory of a computer.

[0017] An exemplary apparatus includes one or more processors and one or more memories including computer program code. The one or more memories and the computer program code are configured to, together with the one or more processors, cause the apparatus to perform operations including: determining, by a user equipment in a wireless network, that the user equipment has been configured with one or more carriers, the one or more carriers to be used as secondary service cell carriers in the wireless network; using, by the user equipment, a selected one of the one or more carriers as a selected secondary service cell carrier, and executing a request for a cell on the selected secondary service cell carrier to become a secondary service cell for the user equipment; and receiving, by the user equipment, a response from the cell regarding a successful request to make the cell become a secondary service cell for the user equipment.

[0018] An exemplary computer program product includes a computer-readable storage medium carrying computer program code, which is implemented in the computer-readable storage medium and is used with a computer. The computer program code includes: a code for determining, by a user equipment in a wireless network, that the user equipment has been configured with one or more carriers, the one or more carriers to be used as secondary service cell carriers in the wireless network; a code for the user equipment to use a selected one of the one or more carriers as a selected secondary service cell carrier, to execute a request for a cell on the selected secondary service cell carrier to become a secondary service cell for the user equipment; and a code for the user equipment to receive a response from the cell regarding the success of the request to make the cell become a secondary service cell for the user equipment.

[0019] In another exemplary embodiment, an apparatus includes: a component for determining, by a user equipment in a wireless network, that the user equipment has been configured with one or more carriers, which are to be used for secondary service cell carriers in the wireless network; a component for executing, by the user equipment, a request for a cell on the selected secondary service cell carrier to become a secondary service cell for the user equipment using a selected one of the one or more carriers as the selected secondary service cell carrier; and a component for receiving, by the user equipment, a response from the cell regarding the success of the request to make the cell become a secondary service cell for the user equipment.

[0020] In another exemplary embodiment, a method is disclosed, the method comprising receiving, at a cell in a wireless network, on a carrier, a request sent by a user equipment to make the cell a secondary cell for the user equipment. The method also comprises indicating, by the cell to the user equipment, that the request to make the cell a secondary cell for the user equipment is successful.

[0021] Additional exemplary embodiments include a computer program including code for performing the method described in the previous paragraph when the computer program is run on a processor. According to the computer program of this paragraph, wherein the computer program is a computer program product including a computer readable medium, the computer readable medium carrying computer program code, the computer program code being implemented in the computer readable medium and for use with a computer. Another example is a computer program according to this paragraph, wherein the program can be directly loaded into the internal memory of a computer.

[0022] An exemplary apparatus includes one or more processors and one or more memories including computer program code. The one or more memories and the computer program code are configured to, together with the one or more processors, cause the apparatus to perform operations including: receiving, at a cell in a wireless network, on a carrier, a request sent by a user equipment to make the cell become a secondary cell for the user equipment; and indicating, by the cell to the user equipment, that the request to make the cell become a secondary cell for the user equipment is successful.

[0023] An exemplary computer program product includes a computer-readable storage medium carrying computer program code, which is implemented in the computer-readable storage medium and is used with a computer. The computer program code includes: code for receiving a request sent by a user equipment on a carrier at a cell in a wireless network to make the cell become a secondary cell for the user equipment; and code for indicating to the user equipment by the cell that the request to make the cell become a secondary cell for the user equipment is successful.

[0024] In another exemplary embodiment, an apparatus includes: an apparatus for receiving, on a carrier at a cell in a wireless network, a request sent by a user equipment to make the cell a secondary cell for the user equipment; and an apparatus for indicating, by the cell to the user equipment, that the request to make the cell a secondary cell for the user equipment is successful. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In the attached picture:

[0026] Figure 1 is a block diagram of one possible and non-limiting exemplary system in which exemplary embodiments may be practiced;

[0027] Figure 2 It is a schematic diagram of the Tx beam changing due to UE movement;

[0028] Figure 3 is a signaling diagram of a method for providing and using an implicit PSCell according to an exemplary embodiment;

[0029] Figure 4 is a logic flow diagram for providing and using an implicit PSCell performed by a UE and illustrating the operation of one or more exemplary methods for performing functions, the results of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and / or interconnecting means according to exemplary embodiments; and

[0030] Figure 5 is a logic flow diagram executed by a cell for providing and using an implicit PSCell, and illustrates the operation of one or more exemplary methods for performing functions according to exemplary embodiments, the execution results of computer program instructions implemented on a computer-readable memory, functions performed by logic implemented in hardware, and / or interconnection means. DETAILED DESCRIPTION

[0031] The following abbreviations that may be found in the specification and / or drawings are defined as follows:

[0032] 3GPP: Third Generation Partnership Project

[0033] 5G: Fifth Generation

[0034] 5GC: 5G core network

[0035] AMF: Access and Mobility Management Function

[0036] BS: Base Station

[0037] CA: Carrier Aggregation

[0038] CC: Component Carrier

[0039] comm.: communication

[0040] CSI: Channel State Information

[0041] CSI-RSRP: CSI reference signal received power

[0042] CSI-RSRQ: CSI reference signal reception quality

[0043] CSI-SNIR: CSI signal-to-interference-noise ratio

[0044] CQI: Channel Quality Information

[0045] CU: Central Unit

[0046] DC: Dual Connect

[0047] DCCA: Dual Connectivity and Carrier Aggregation

[0048] DL: Downlink (from base station to UE)

[0049] DU: Distributed Unit

[0050] eNB (or eNodeB): Evolved Node B (e.g., LTE base station)

[0051] EN-DC: E-UTRA-NR Dual Connectivity

[0052] en-gNB or En-gNB: A node that provides NR user plane and control plane protocol termination towards the UE and acts as a secondary node in EN-DC

[0053] euCA: Enhanced Utilization of CA

[0054] E-UTRA: Evolved Universal Terrestrial Radio Access, also known as LTE radio access technology

[0055] FR1: Frequency range 1 (e.g., below 6 GHz)

[0056] FR2: Frequency Range 2 (e.g., above 6 GHz, such as 24.25 to 52.6 GHz)

[0057] FR4: Frequency Range 4 (e.g., above 52 GHz)

[0058] gNB (or gNodeB): a base station for 5G / NR, i.e., a node that provides NR user plane and control plane protocol termination towards the UE and is connected to the 5GC via the NG interface

[0059] HO: Handover

[0060] I / F: Interface

[0061] L1-RSRP: Layer 1 (physical layer) RSRP

[0062] LTE: Long Term Evolution

[0063] MAC: Media Access Control

[0064] MCG: Master Cell Group

[0065] MME: Mobility Management Entity

[0066] MO: Mobile (device) initiated

[0067] MR-DC: Multi-Radio Dual Connectivity

[0068] MT: Mobile (device) terminated

[0069] ng or NG: Next Generation

[0070] ng-eNB or NG-eNB: Next Generation eNB

[0071] NN-DC: New Radio-New Radio Dual Connectivity

[0072] NR: New Radio

[0073] N / W or NW: Network

[0074] PCell: Primary cell

[0075] PDCP: Packet Data Convergence Protocol

[0076] PHY: Physical layer

[0077] PRACH: Physical Random Access Channel

[0078] PScell: primary and secondary cells

[0079] RAN: Radio Access Network

[0080] rel: version

[0081] RLC: Radio Link Control

[0082] RRH: Remote Radio Head

[0083] RRC: Radio Resource Control

[0084] RSRP: Reference Signal Received Power

[0085] RSRQ: Reference Signal Received Quality

[0086] RU: Radio Unit

[0087] Rx: Receiver or Receive

[0088] SCell: Secondary cell

[0089] SCG: Secondary Cell Group

[0090] SDAP: Service Data Adaptation Protocol

[0091] SGW: Serving Gateway

[0092] SMF: Session Management Function

[0093] SS: Synchronous signal

[0094] SSB: Synchronization Signal Block

[0095] SS-RSRP: SS reference signal received power

[0096] SS-RSRQ: SS reference signal reception quality

[0097] SS-SNIR: SS signal-to-interference-noise ratio

[0098] TS: Technical Specification

[0099] Tx: Transmitter or Transmission

[0100] UE: User Equipment (e.g., wireless device, typically a mobile device)

[0101] UL: Uplink (from UE to base station)

[0102] UPF: User Plane Function

[0103] UTRA: Universal Terrestrial Radio Access

[0104] WG: Working Group

[0105] WI: Work Item

[0106] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration". Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. All embodiments described in this detailed description are exemplary embodiments provided to enable those skilled in the art to make or use the invention and are not intended to limit the scope of the invention as defined by the claims.

[0107] The exemplary embodiments herein describe techniques for providing and using implicit PSCells. Additional description of these techniques is presented after describing a system in which the exemplary embodiments may be used.

[0108] Steering Figure 1, which shows a block diagram of one possible and non-limiting exemplary system in which exemplary embodiments may be practiced. A user equipment (UE) 110, multiple radio access network (RAN) nodes 170 and 180 (e.g., gNBs), and (multiple) network elements 190 are shown. Multiple RAN nodes 170 and 180 are shown: a first RAN node 170, shown as a PCell; a second RAN node 180-1, shown as a PSCell; and (possibly) one or more other RAN nodes 180, shown as ellipses and 180-N, which are other SCells. The MCG includes the RAN node 170, the SCell 180-1, and any additional SCells 180-2, ..., 180-N. The SCG includes (multiple) SCells 180. Note that there can be a single SCell 180 or multiple SCells from SCell 180-1 to SCell 180-N.

[0109] exist Figure 1In the present invention, a user equipment (UE) 110 wirelessly communicates with a wireless (e.g., cellular) network 100. A UE is a wireless device that can access a wireless network, typically a mobile device. The UE 110 includes one or more processors 120, one or more memories 125, and one or more transceivers 130 interconnected by one or more buses 127. Each of the one or more transceivers 130 includes a receiver Rx 132 and a transmitter Tx 133. The one or more buses 127 may be an address bus, a data bus, or a control bus, and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, an optical fiber or other optical communication device, etc. The one or more transceivers 130 are connected to one or more antennas 128. The one or more memories 125 include computer program code 123. The UE 110 includes a communication (comm.) module 140, which includes one or both of the parts 140-1 and / or 140-2, and the communication module 140 may be implemented in a variety of ways. The communication module 140 may be implemented in hardware as a communication module 140-1, such as being implemented as part of one or more processors 120. The communication module 140-1 may also be implemented as an integrated circuit or by other hardware implementations such as a programmable gate array. In another example, the communication module 140 may be implemented as a communication module 140-2, which is implemented as a computer program code 123 and is executed by one or more processors 120. For example, one or more memories 125 and the computer program code 123 may be configured to cause the user equipment 110 to perform one or more of the operations described herein together with the one or more processors 120. The UE 110 communicates with the RAN node 170 via a wireless link 111-1, communicates with the RAN node 180-1 via a link 111-2, and so on, and communicates with the RAN node 180-N via a link 111-N+1.

[0110] RAN nodes 170 and 180 are base stations that provide access to the wireless network 100 for wireless devices such as UE 110. RAN nodes 170 and 180 may be, for example, base stations for 5G, also known as New Radio (NR). Although 5G is mainly discussed herein, RAN node 170 may also be an eNB (evolved NodeB) base station for LTE (Long Term Evolution) or any other suitable base station. In 5G, each RAN node 170 or 180 may be a NG-RAN node, which is defined as a gNB or ng-eNB. A gNB is a node (e.g., (multiple) network elements 190) that provides NR user plane and control plane protocol termination towards the UE and is connected to the 5GC via an NG interface. For ease of reference herein, RAN nodes 170 and 180 are primarily described as gNBs, but may also be other nodes. In addition, possible internal circuit systems in RAN node 170 are described herein, and it is assumed that other RAN nodes 180-1 to 180-N are similar.

[0111] The ng-eNB is a node that provides E-UTRA user plane and control plane protocol termination towards the UE and is connected to the 5GC via the NG interface. The NG-RAN node may include multiple gNBs, which may also include a central unit (CU) (gNB-CU) 196 and (multiple) distributed units (DU) (gNB-DU), of which DU 195 is shown. Note that the DU may include or be coupled to a radio unit (RU) and control the radio unit. The gNB-CU is a logical node that hosts the RRC, SDAP and PDCP protocols of the gNB or the RRC and PDCP protocols of the en-gNB, which control the operation of one or more gNB-DUs. The gNB-CU terminates the F1 interface connected to the gNB-DU. The F1 interface is shown as reference numeral 198, although reference numeral 198 also shows a link between a remote element of the RAN node 170 and a centralized element of the RAN node 170, such as a link between a gNB-CU 196 and a gNB-DU 195. The gNB-DU is a logical node that hosts the RLC, MAC, and PHY layers of a gNB or en-gNB, and its operation is controlled in part by the gNB-CU. One gNB-CU supports one or more cells. One cell is supported by only one gNB-DU. The gNB-DU terminates the F1 interface 198 connected to the gNB-CU. Note that the DU 195 is considered to include the transceiver 160, for example as part of the RU, but some examples thereof may have the transceiver 160 as part of a separate RU, for example, controlled by and connected to the DU 195.

[0112] The RAN node 170 includes one or more processors 152, one or more memories 155, one or more network interfaces (N / WI / F) 161, and one or more transceivers 160 interconnected by one or more buses 157. Each of the one or more transceivers 160 includes a receiver Rx 162 and a transmitter Tx 163. The one or more transceivers 160 are connected to one or more antennas 158. The one or more memories 155 include computer program code 153. The CU 196 may include (multiple) processors 152, memories 155, and network interfaces 161. Note that the DU 195 may also contain its own memory / memory and (multiple) processors and / or other hardware, but these are not shown.

[0113] The RAN node 170 includes a communication (comm.) module 150, which includes one or both of the parts 150-1 and / or 150-2, which can be implemented in a variety of ways. The communication module 150 can be implemented in hardware as the communication module 150-1, such as being implemented as part of one or more processors 152. The communication module 150-1 can also be implemented as an integrated circuit or by other hardware such as a programmable gate array. In another example, the communication module 150 can be implemented as a communication module 150-2, which is implemented as a computer program code 153 and executed by one or more processors 152. For example, one or more memories 155 and computer program code 153 are configured to, together with one or more processors 152, cause the RAN node 170 to perform one or more of the operations described herein. Note that the functionality of the communication module 150 can be distributed, such as distributed between the DU 195 and the CU 196, or implemented only in the DU 195.

[0114] One or more network interfaces 161 communicate over a network, such as via links 176 and 131. Two or more RAN nodes 170 / 180 communicate using, for example, link 176. Link 176 may be wired or wireless or both, and may implement, for example, an Xn interface for 5G, an X2 interface for LTE, or other suitable interfaces for other standards.

[0115] The one or more buses 157 may be an address bus, a data bus, or a control bus, and may include any interconnection mechanism, such as a series of wires on a motherboard or integrated circuit, an optical fiber or other optical communication device, a wireless channel, etc. For example, the one or more transceivers 160 may be implemented as a remote radio head (RRH) 195 for LTE or a distributed unit (DU) 195 for a gNB implementation for 5G, while other elements of the RAN node 170 may be physically located at a different location from the RRH / DU, and the one or more buses 157 may be partially implemented as, for example, an optical fiber cable or other suitable network connection for connecting other elements of the RAN node 170 (e.g., a central unit (CU), a gNB-CU) to the RRH / DU 195. Reference numeral 198 also indicates those suitable network links (multiple).

[0116] Note that the descriptions herein refer to "cells" performing functions, but it should be clear that the base stations that form the cells will perform these functions. The cell constitutes part of the base station. That is, each base station can have multiple cells. For example, a single carrier frequency and associated bandwidth can have three cells, each covering one-third of a 360-degree area, so the coverage area of ​​a single base station covers an approximate ellipse or circle. In addition, each cell can correspond to a single carrier, and a base station can use multiple carriers. Therefore, if each carrier has three 120-degree cells and there are two carriers, the base station has a total of 6 cells.

[0117] The wireless network 100 may include one or more network elements 190, which may include core network functions and provide connectivity to additional networks such as a telephone network and / or a data communications network (e.g., the Internet) via one or more links 181. Such core network functions for 5G may include access and mobility management functions (AMFs) and / or user plane functions (UPFs) and / or session management functions (SMFs). Such core network functions for LTE may include MME (mobility management entity) / SGW (serving gateway) functions. These are merely exemplary functions that the network element(s) 190 may support, and note that both 5G and LTE functions may be supported. The RAN node 170 / 180 is coupled to the network element 190 via a link 131. The link 131 may be implemented, for example, as an NG interface for 5G or an S1 interface for LTE or other suitable interfaces for other standards. The network element 190 includes one or more processors 175, one or more memories 171, and one or more network interfaces (N / WI / F) 182 interconnected by one or more buses 185. The one or more memories 171 include computer program code 173. The one or more memories 171 and the computer program code 173 are configured to, together with the one or more processors 175, cause the network element 190 to perform one or more operations.

[0118] The wireless network 100 can implement network virtualization, which is a process of combining hardware and software network resources and network functions into a single software-based management entity (virtual network). Network virtualization involves platform virtualization, which is usually combined with resource virtualization. Network virtualization is divided into external network virtualization or internal network virtualization. External network virtualization combines many networks or parts of networks into virtual units, and internal network virtualization provides network-like functions for software containers on a single system. Note that the virtualized entities generated by network virtualization are still implemented using hardware such as processors 152 or 175 and memories 155 and 171 to some extent, and such virtualized entities also produce technical effects.

[0119] Computer readable memories 125, 155, and 171 may be of any type suitable for the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. Computer readable memories 125, 155, and 171 may be means for performing storage functions. Processors 120, 152, and 175 may be of any type suitable for the local technical environment and, as non-limiting examples, may include one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. Processors 120, 152, and 175 may be means for performing functions, such as controlling UE 110, RAN nodes 170 / 180, and other functions described herein.

[0120] In general, various embodiments of user device 110 may include, but are not limited to, a cellular telephone (such as a smart phone), a tablet computer, a personal digital assistant (PDA) with wireless communication capabilities, a portable computer with wireless communication capabilities, an image capture device with wireless communication capabilities (such as a digital camera), a gaming device with wireless communication capabilities, a music storage and playback device with wireless communication capabilities, an Internet device (including an Internet of Things device) that allows wireless Internet access and possible browsing, a tablet computer with wireless communication capabilities, and portable units or terminals incorporating a combination of such functionality.

[0121] Having thus introduced a suitable but non-limiting technical context for the practice of exemplary embodiments of this invention, the exemplary embodiments will now be described in more detail.

[0122] As previously mentioned, NR system design differs from LTE in several aspects, some of which affect possible solutions for reducing DC and CA establishment delays. For example, NR includes frequencies in a higher frequency range (e.g., FR2, although FR4 is also possible), where it is assumed that both the base station (e.g., gNB 170 / 180) and the UE will use both transmit (Tx) beams and receive (Rx) beams.

[0123] In particular, in FR2, it is assumed that both the gNB 170 / 180 and the UE 110 will apply beamforming to increase the link budget to increase cell coverage and improve UE performance. This is considered necessary due to the increased path loss in higher carrier frequencies.

[0124] A diagram illustrating the gNB Tx beamforming aspect is shown in Figure 2It is shown in “R4-1904287, Nokia, Nokia Shanghai Bell, “Discussion on NR SCell activation delay in FR2”, 3GPPTSG-RAN4 Meeting#90bis, Xi'an, China, 8-12 April 2019”. Figure 2 is an illustration of a Tx beam change due to UE movement. The gNB 170 is shown as creating six beams 230-1 to 230-6 within the cell 240. In this example, reference numeral 210 indicates an initial position where the UE 110 is in the coverage area of ​​the beam 230-3. The UE 110 has information of the beam 230-3 and the cell 240. The UE 110 moves to another position shown by reference numeral 220, and the UE 110 is out of the coverage of the beam 230-3, but the UE 110 is still in the coverage of the beam 230-4 of the same cell 240.

[0125] Depending on the network deployment and carrier frequency used, the basic coverage area of ​​DL beam 230 may be quite limited. This means that if UE 110 Figure 2 As shown, the UE will enter the coverage of another DL beam 230. This is similar to the Rx beam of the UE (not shown), where movement, for example due to rotation, etc., may result in a change of the Rx beam required when receiving a given DL beam from the gNB.

[0126] It can be appreciated that such UE movement resulting in Tx beam and / or Rx beam changes increases the connection uncertainty between the UE 110 and the network 100 in terms of when a given Tx / Rx beam set can be assumed to be valid (over time).

[0127] The beamforming aspect has led to lengthy discussions in 3GPP, especially in WG4 (Working Group 4, responsible for developing specifications dealing with UTRA, Evolved UTRA, etc.) regarding assumed HO disruptions, SCell activation delays and PSCell addition delays.

[0128] The very basic question under discussion is the following: Assuming that the Rx / Tx beam pair has not changed, for how long can the detected measurements and reported cells be considered valid?

[0129] When looking at the utilization of cells in FR2 or typically cells above 6 GHz (e.g., FR4), an important scenario use case for NR is to use an NR FR2 carrier and a PCell in FR1, both using LTE or NR. One such example is that the PCell is in FR1 and the PSCell is in FR2. In traditional (and FR1), when a PSCell is added, the addition is predictable assuming that the network configures the PSCell shortly after the UE reports the potential PSCell (see 3GPP TS36.133 and TS 38.133). However, as described above, when the added PSCell is in FR2 or above 6 GHz, it becomes very difficult to define and / or predict the delay associated with the addition of the PSCell. In particular, when the UE is moving and / or in a changing environment (e.g., due to high beam granularity, any small movement of the UE or device may cause significant fluctuations in signal quality), the delay increases when the PSCell is added and until the PSCell can be used for scheduling, and in most cases becomes unpredictable.

[0130] This increased latency (along with the uncertainty of whether the reported beam is still valid) reduces system performance and efficiency in utilizing possible FR2 or above 6GHz cells as PSCells for offloading. That is, a method is needed to improve visibility and predictability about when a PSCell will be ready for use and therefore reduce PSCell addition time.

[0131] To this end, in an exemplary embodiment, a method is proposed, in which a UE is configured with a "PSCell carrier." A PSCell carrier indicates that any cell detected on the PSCell carrier is or can be assumed to be a potential PSCell.

[0132] The method may also include: if the UE detects that a cell on the PSCell carrier is "good enough" (e.g., satisfies (multiple) predefined conditions) and (depending on the scenario) data transmission is in progress (e.g., or is about to start or start or be initiated within a certain time period), the UE will (e.g., in addition to performing access on the PCell) perform access to the cell (e.g., formed by gNB 180-1) on the PSCell carrier (i.e., on a potential "PSCell") .

[0133] Upon or if network 100 receives an access request from a UE on a cell (e.g., a cell for a PSCell formed by gNB 180-1) on a "PSCell carrier," the network may choose to accept use of the cell as a PSCell, e.g., by responding to the UE access request to the accessed cell (potential "PSCell") in response to the access request (e.g., a random access response). This may use normal PRACH procedures, for example. By responding to the UE access request, network 100 thereby confirms that the cell will be used as a PSCell.

[0134] The network 100 (e.g., gNB 180-1) remains the controlling entity for adding the PSCell and necessary parameters. At the same time, the latency of adding the PSCell is significantly reduced due to the reduction of signaling overhead and PSCell configuration time.

[0135] An illustrative example is now provided to illustrate how the method can be implemented in NR. This is a non-limiting example using a PCell in FR1 (e.g., LTE or NR PCell) and assuming that the PSCell carrier is a carrier in FR2. However, other combinations are not excluded. The signaling flow is an illustrative example, and other access methods, such as PRACH procedures, may also be used.

[0136] This example uses Figure 3 , Figure 3 is a signaling diagram of a method for providing and using an implicit PSCell according to an exemplary embodiment. PCell 310 is formed by gNB 170, and Pcarrier 320 is broadcast or signaled by gNB 180-1 (e.g., if the cell is added in this way, PSCell 325 is created). It is assumed that each of gNB 170 / 180 is partially controlled by its corresponding communication module 150.

[0137] In this example, UE 110 is in connected mode in block 315. Network 100 (e.g., gNB 170, PCell 310) configures the UE to perform inter-frequency measurements on a carrier in, for example, FR2, which is intended for, for example, EN-DC configuration for offloading. See signaling 323. That is, the cells on the carrier in FR2 and possibly the cells in cell list 326 are intended for use as PSCells. This cell list 326 may also be empty to indicate that any cell is suitable for use as a PSCell (e.g., in the case of a large CU containing multiple DUs).

[0138] UE 110 will perform inter-frequency measurements on the carrier (Pcarrier) in block 330. In one example, the UE will not be configured with any reporting criteria for the carrier, and, for example, UE 110 will not trigger any measurement reports on PCell due to measurements on this FR2 carrier. In another example, the UE is configured such that the measurement configuration includes information that enables the UE to identify the carrier as a "PSCell carrier" type.

[0139] In block 335, the UE searches for cells, for example, by receiving SSBs 340-1 and 340-2. In block 345, the UE may make one or more RSRP measurements using a physical signal such as SS Reference Signal Received Power (SS-RSRP). Note that RSRP is just one exemplary measurement that may be made.

[0140] In some embodiments, once data traffic is initiated (e.g., or if data traffic is ongoing) (see block 350), and a cell on the FR2 PSCell carrier (Pcarrier 320) is assessed to be "good enough" (e.g., according to some criteria / criteria, such as RSRP / RSRQ or similar measurement(s) exceeding one or more thresholds), the UE will initiate an access procedure on the FR2 cell on the PSCell carrier 320. There may be multiple conditions for when the UE 110 is caused to perform an access procedure on a cell on the PSCell carrier 320, but at least one of them is satisfied, such as:

[0141] 1) The measurement from the cell is better than a given threshold;

[0142] 2) the cell is detectable and the cell identity belongs to a list of indicated cell identities indicated by the network (e.g., list 326);

[0143] 3) upon request from the network (e.g., from PCell 310); and / or

[0144] 4) If the data buffer (UE or network side) exceeds a certain threshold.

[0145] For NR, measurements may include any one or more of the following: SS-RSRP, SS-RSRQ, CSI-RSRP, CSI-RSRQ, SS-SNIR, CSI-SNIR, L1-RSRP, etc. For LTE, these may include, for example, RSRP, RSRQ, CSI, CQI, CSI-RSRP, RS-SNIR, RSSI, NR-SS-RSRP, NR-SS-RSRQ, etc.

[0146] Note that the UE may have data transmission initiated (or scheduled (eg, triggered) to initiate), and this may apply if data buffering in the UE exceeds a threshold (ie, the UE has some traffic and therefore can use the PSCell).

[0147] If initiated by the wireless network (see (3)), this can be independent of the service. That is, the network (e.g., PCell) will request this when more capacity is needed. Therefore, since the UE can determine which cell is currently the strongest cell, the UE can select that cell - as long as the cell meets the conditions set by the network. Note that this is different from the current LTE / NR working method where the network configures a specific cell for the UE. This means waiting for the measurement report from the UE so that the network can know which cell the network should configure.

[0148] Regarding (1) and (2) above, one possible approach is to configure the cell as a PSCell when needed (i.e., when the service comes from the MO / MT). In other words, in response to a data service being initiated (or ongoing or scheduled (e.g., triggered) to start, e.g., within a certain time period or immediately), the UE can perform (1) or (2). This restriction makes sense when the UE adds cells autonomously, although it is not absolutely necessary. However, when the network initiates the process, the network may also do so before the service itself is initiated, although the network may not do so unless the network somehow anticipates the need to do so. Anticipation is possible, but it is possible that the network may not be configured for this purpose.

[0149] If one or more conditions are met (in Figure 3 In the example of , in box 355, the cell SS-RSRP is greater than the threshold), and the UE performs access to the FR2 cell on the PSCell carrier 320, the network can reply to the request and thereby confirm that the cell will be used, for example, as the PSCell 325. In one example, the UE initiates an access request on the cell via signaling 360, and uses the PRACH process 365. Note that the UE can signal that it wants to add a PSCell during the random access procedure. For example, instead of requesting an RRC connection establishment, the UE 110 requests (reference numeral 362) to add the cell as a PSCell, for example in Msg3, the UE can send a request to add the cell as a PSCell. As is well known, Msg 3 is the third message in the random access procedure (after the preamble transmission and the random access response), and the message can typically be, for example, an RRC establishment request message. A new message requesting the establishment of a PSCell can be sent, or a modified version of some existing message carrying the new request can be sent. Note that this is different from the current situation where the PSCell is configured by the PCell (usually based on measurement reports from the UE). exist Figure 3 In the example of , by contrast, the UE is requesting that the cell on Pcarrier 320 become the UE's PSCell. If the UE receives a response to the access (which may be in a PRACH procedure or signaling 385 described below), the UE may assume that the cell will be used as the PSCell 325 and act accordingly.

[0150] If the network (e.g., gNB 180-1) wants to use the indicated cell on the PSCell carrier 320 as a PSCell 325, the network responds to the UE access request. Otherwise, the network does not respond to the request in one example or denies the UE access request in another example. Once the network confirms the use of the cell as the PSCell 325, the network configures any necessary missing parameters for the PSCell to the UE (e.g., see signaling 385 and (multiple) parameters 386). These parameters, such as general RRC configuration, dedicated RRC configuration, PHY configuration parameters, MAC configuration for SCell, STAG configuration, etc., will enable the UE to access the PSCell. In one example, as Figure 3 As shown, the UE may assume that the missing parameters are received from the confirmed PSCell 325 on the PSCell carrier 320. However, the parameter(s) may also be received via the PCell 310.

[0151] As optional signaling in block 370, PSCell 325 on Pcarrier 320 may send a request PSCell add message in signaling 375, and PCell 310 responds with a PSCell add acknowledgement (ack) in signaling 380. Note that Figure 3 It is assumed that the PCell 310 accepts the PSCell addition. Another possibility is that the PSCell addition is rejected, for example, the UE's configuration may be outdated and reconfiguration has not been performed. In this case, the process will stop at some point in time and the UE will be signaled that the request was rejected.

[0152] Once the PSCell is added, for example, DC operation may be performed by the PCell 310, the UE 110, and the PSCell 325. Such DC operation is known.

[0153] In another example, a list of cells / carriers to be measured when in the inactive / idle state may be configured to the UE before the UE transitions to the idle / inactive state. Later, upon connection establishment (e.g., transitioning the UE to connected mode with a PCell), the UE will use these measured cells for (P)SCell fast establishment in the idle / inactive state. In this case, the UE will be indicated that these cells may be added as implicit (e.g., virtual) PSCells, i.e., without explicit network configuration, but based on a request initiated by the UE.

[0154] Although Figure 3 It is aimed at adding PSCell 325, but Figure 3 It may also be implemented to add a SCell 325-1. This may happen, for example, if a PSCell 325 already exists and the UE wants to add another SCell.

[0155] Exemplary advantages and technical effects include one or more of the following:

[0156] 1) There is no need to report the potential PSCell on the PCell;

[0157] 2) The exemplary embodiment eliminates the uncertainty of delay by obtaining reports only when PSCell usage is required;

[0158] 3) Exemplary embodiments reduce the need to add PSCells for unnecessarily long periods of time;

[0159] 4) Exemplary embodiments reduce UE and network complexity; and / or

[0160] 5) Exemplary embodiments may require less UE measurement work.

[0161] Steering Figure 4 , which is a logic flow diagram for providing and using an implicit PSCell performed by UE 110. The diagram illustrates the operation of one or more exemplary methods for performing functions, the result of execution of computer program instructions embodied on a computer readable memory, functions performed by logic implemented in hardware, and / or interconnecting means in accordance with exemplary embodiments. Figure 4 The blocks in are assumed to be executed by UE 110 , for example under the control of communication module 140 .

[0162] Figure 4The process in begins at block 410, where UE 110 determines that the user equipment has been configured with one or more carriers to be used as secondary cell carriers in the wireless network. In block 420, the user equipment performs a request for a cell on the selected secondary cell carrier to become a secondary cell for the user equipment using a selected one of the one or more carriers as the selected secondary cell carrier. The user equipment receives a response from the cell regarding the success of the request to make the cell become the secondary cell for the user equipment. This occurs in block 430.

[0163] The following is based on the example 1 Figure 4 Additional examples of .

[0164] Example 2. The method according to Example 1 further includes detecting, by the user equipment, that the cell satisfies one or more predefined conditions, and wherein the request for the cell to become a secondary cell is performed in response to detecting that the cell satisfies the one or more predefined conditions.

[0165] Example 3. A method according to Example 2, wherein detecting that the cell satisfies one or more predefined conditions is performed in response to a current data transmission from the user equipment to the primary cell being an ongoing transmission or having been previously initiated or started but not yet in progress or being scheduled or triggered to start within a period of time or immediately.

[0166] Example 4. A method according to any one of Examples 2 or 3, wherein detecting that the cell satisfies one or more predefined conditions includes determining that a measurement from the cell is better than a given threshold.

[0167] Example 5. A method according to Example 4, wherein before the user equipment transitions to an idle / inactive state, the user equipment is configured with a list of carriers to be measured when in the inactive / idle state, and wherein the method further comprises, in response to transitioning to a connected mode with a primary cell in the wireless network, the user equipment measuring the carriers in the list while in the inactive / idle state, and using these measurements for executing the request for the cell.

[0168] Example 6. A method according to any one of Examples 4 or 5, wherein the measurement includes one of the following: SS-RSRP, SS-RSRQ, CSI-RSRP, CSI-RSRQ, SS-SNIR, CSI-SNIR, L1-RSRP, RSRP, RSRQ, CSI, CQI, CSI-RSRP, RS-SNIR, RSSI, NR-SS-RSRP, NR-SS-RSRQ.

[0169] Example 7. A method according to any one of Examples 2 or 3, wherein detecting that the cell satisfies one or more predefined conditions includes: determining that the cell is detectable and that the cell identity of the cell belongs to a cell identity list indicated by the wireless network to the user equipment.

[0170] Example 8. The method according to Example 1 also includes receiving a request from a wireless network, wherein the request from the wireless network requests execution of a request to add any secondary cell to the user equipment as a secondary cell of the user equipment, and wherein the execution of the request for the cell to become the secondary cell is performed in response to the request of the wireless network.

[0171] Example 9. The method according to Example 1 further includes: determining whether the data buffer in the user equipment exceeds a first threshold or determining that the wireless network has indicated to the user equipment that the data buffer at the wireless network has exceeded a second threshold, and wherein the execution of the request for the cell to become a secondary cell is performed in response to determining that the data buffer in the user equipment exceeds the first threshold or determining that the wireless network has indicated to the user equipment that the data buffer at the wireless network has exceeded the second threshold.

[0172] Example 10. A method according to Example 9, wherein determining whether the data buffer in the user equipment exceeds a first threshold is performed in response to a current data transmission from the user equipment to the primary cell being an ongoing transmission or having been previously initiated or started but not yet in progress or scheduled or triggered within a period of time or immediately.

[0173] Example 11. A method according to any one of Examples 1 to 10, wherein the response from the cell uses one of a physical random access channel procedure or signaling that occurs after the physical random access channel procedure is completed.

[0174] Example 12. A method according to any one of Examples 1 to 11, wherein the secondary cell is a primary secondary cell and the request for the cell to become a secondary cell of the user equipment is a request for the cell to become the primary secondary cell of the user equipment.

[0175] Example 13. A method according to any one of Examples 1 to 12, wherein the request for the cell to become a secondary service cell of the user equipment is used to allow the user equipment to participate in dual connectivity or carrier aggregation between the user equipment, at least one secondary cell and a primary cell in the wireless network.

[0176] Example 14. The method of any one of Examples 1 to 13, wherein the performing of the request for the cell to become the secondary cell of the user equipment is performed using at least an access procedure to the cell.

[0177] Example 15. The method according to any one of Examples 1 to 14 further includes, in response to receiving from the cell a response regarding the success of the request to make the cell the secondary cell for the user equipment, using the cell as a secondary cell for the user equipment in dual connectivity or carrier aggregation by the user equipment.

[0178] Example 16. A method according to any one of Examples 1 to 15, wherein the one or more carriers are above 6 GHz.

[0179] Example 17. The method of Example 16, wherein the primary cell to which the user equipment is connected operates on a sub-6 GHz carrier.

[0180] refer to Figure 5 , which is a logical flow chart of the steps performed by a cell to provide and use an implicit PSCell (or SCell). Figure 5 The operations of one or more exemplary methods for performing functions according to the exemplary embodiments, the results of execution of computer program instructions implemented on a computer readable memory, functions performed by logic implemented in hardware, and / or interconnected devices are shown. Figure 5 The boxes in are executed by cell 325 (such as generated by gNB 180 and becoming PSCell), for example, under the control of communication module 150.

[0181] In block 510, the gNB / cell 325 receives a request from a user equipment at a cell in a wireless network on a carrier to make the cell a secondary cell for the user equipment. In block 520, the gNB / cell 325 indicates to the user equipment through the cell that the request to make the cell a secondary cell for the user equipment is successful.

[0182] The following is based on the example 18 Figure 5 Additional examples of .

[0183] Example 19. The method of Example 18, further comprising: in response to the receiving and the indicating, performing one or more actions to serve as the secondary cell for the user equipment.

[0184] Example 20. The method of Example 18, wherein performing one or more actions further comprises:

[0185] Sending, by the cell in the wireless network, a request for adding a secondary cell to a primary cell; and

[0186] In response to receiving a primary-secondary cell addition confirmation from the primary cell, the serving as the secondary cell for the user equipment is performed.

[0187] Example 21. A method according to any one of Examples 19 or 20, wherein performing one or more actions also includes sending one or more parameters for the secondary cell by the cell to the user equipment, and the one or more parameters enable the user equipment to access the secondary cell.

[0188] Example 22. A method according to any one of Examples 18 to 21, wherein the carrier is above 6 GHz.

[0189] Example 23. A method according to any one of Examples 18 to 22, wherein the receiving of the request occurs during a physical random access channel process, and the indicating to the user equipment occurs during the physical random access channel process or in one of the signaling that occurs after the physical random access channel process is completed.

[0190] Example 24. A method according to any one of Examples 18 to 23, wherein the secondary cell is a primary secondary cell, and the request of the user equipment for the cell to become a secondary cell for the user equipment is a request for the cell to become the primary secondary cell for the user equipment.

[0191] Additional examples are as follows.

[0192] Example 25. A computer program comprising code for performing a method according to any one of Examples 1 to 24 when the computer program is run on a computer.

[0193] Example 26. A computer program according to Example 25, wherein the computer program is a computer program product comprising a computer readable medium carrying computer program code embodied in the computer readable medium for use with the computer.

[0194] Example 27. A computer program according to Example 25, wherein the computer program is directly loadable into an internal memory of the computer.

[0195] Example 28. An apparatus comprising:

[0196] means for determining, by a user equipment in a wireless network, that the user equipment has been configured with one or more carriers, the one or more carriers to be used as secondary cell carriers in the wireless network;

[0197] means for executing, by the user equipment, a request for a cell on the selected secondary cell carrier to become a secondary cell for the user equipment using the selected one of the one or more carriers as the selected secondary cell carrier; and

[0198] Means for receiving, by the user equipment, a response from the cell regarding success of the request for the cell to become the secondary cell for the user equipment.

[0199] Example 29. The apparatus of Example 28 further comprises a component for performing a method of any one of Examples 2 to 17.

[0200] Example 30. A user device comprising an apparatus according to any one of Examples 28 or 29.

[0201] Example 31. An apparatus comprising:

[0202] means for receiving, at a cell in a wireless network, on a carrier, a request by a user equipment to make the cell a secondary cell for the user equipment; and

[0203] means for indicating, by the cell to the user equipment, that the request for the cell to become a secondary cell for the user equipment is successful.

[0204] Example 32. The device according to Example 31 also includes a component for performing a method according to any one of Examples 19 to 24.

[0205] Example 33. A base station comprising an apparatus according to any one of Examples 31 or 32.

[0206] Example 34. A wireless communication system comprising an apparatus according to any one of Examples 28 or 29 and an apparatus according to any one of Examples 31 or 32.

[0207] Example 35. An apparatus comprising:

[0208] at least one processor; and

[0209] at least one memory including computer program code,

[0210] The at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to perform operations comprising:

[0211] Determining, by a user equipment in a wireless network, that the user equipment has been configured with one or more carriers, where the one or more carriers are to be used as secondary cell carriers in the wireless network;

[0212] receiving, by the user equipment, from the cell a response regarding success of the request for the cell to become the secondary cell for the user equipment; and

[0213] A response is received, by the user equipment, from the cell regarding success of the request for the cell to become the secondary cell for the user equipment.

[0214] Example 36. An apparatus comprising:

[0215] at least one processor; and

[0216] at least one memory including computer program code,

[0217] The at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to perform operations comprising:

[0218] receiving, at a cell in a wireless network, on a carrier, a request from a user equipment to make the cell a secondary cell for the user equipment; and

[0219] The cell indicates to the user equipment that the request for the cell to become a secondary cell for the user equipment is successful.

[0220] Example 37. A computer program product, comprising a computer readable storage medium bearing computer program code embodied in the computer readable storage medium for use with a computer, the computer program code comprising:

[0221] code for determining, by a user equipment in a wireless network, that the user equipment has been configured with one or more carriers, the one or more carriers to be used as secondary cell carriers in the wireless network;

[0222] code for executing, by the user equipment, a request for a cell on the selected secondary cell carrier to become a secondary cell for the user equipment using the selected one of the one or more carriers as the selected secondary cell carrier; and

[0223] Code for receiving, by the user equipment, a response from the cell regarding success of the request for the cell to become the secondary cell for the user equipment.

[0224] Example 38. A computer program product, comprising a computer readable storage medium carrying computer program code, the computer program code being embodied in the computer readable storage medium and for use with a computer, the computer program code comprising:

[0225] Code for receiving, at a cell in a wireless network, on a carrier, a request by a user equipment to make the cell a secondary cell for the user equipment; and

[0226] A code for indicating, by the cell to the user equipment, that the request for the cell to become a secondary cell for the user equipment is successful.

[0227] As used in this application, the term "circuitry" may refer to one or more or all of the following:

[0228] (a) hardware circuit implementation only (such as implementation only in analog and / or digital circuitry), and

[0229] (b) a combination of hardware circuitry and software, such as (as applicable): (i) a combination of analog and / or digital hardware circuitry and software / firmware, and (ii) any portion of hardware processor(s) (including digital signal processor(s), software and memory(s)) with software that work together to enable a device (such as a mobile phone or server) to perform various functions, and

[0230] (c) Hardware circuits and / or processor(s), such as microprocessor(s) or portions of microprocessor(s), that require software (e.g., firmware) to operate, but the software may not be present when the software is not required for operation.

[0231] This definition of circuitry applies to all uses of the term in this application, including in any claims. As another example, as used in this application, the term circuitry also covers an implementation of only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers (for example and if applicable to a particular claim element) a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing device or network device.

[0232] The embodiments herein may be implemented in software (executed by one or more processors), hardware (e.g., application specific integrated circuits), or a combination of software and hardware. In example embodiments, the software (e.g., application logic, instruction sets) is maintained on any of a variety of conventional computer-readable media. In the context of this document, a "computer-readable medium" may be any medium or device that contains, stores, communicates, propagates, or transmits instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer, an example of which is a computer. Figure 1Computer-readable media may include computer-readable storage media (e.g., memory 125, 155, 171 or other devices), which may be any medium or device that contains, stores, and / or transmits instructions for use by or in conjunction with an instruction execution system, apparatus, or device, such as a computer. Computer-readable storage media do not include propagating signals.

[0233] If desired, the different functions discussed herein may be performed in different orders and / or simultaneously with each other. In addition, if desired, one or more of the above functions may be optional or may be combined.

[0234] Although various aspects of the invention are set out in the independent claims, further aspects of the invention comprise other combinations of features from the described embodiments and / or the dependent claims with features of the independent claim, and not just the combinations explicitly stated in the claims.

[0235] It should also be noted herein that although the above describes example embodiments of the invention, these descriptions should not be viewed in a limiting sense. Rather, numerous variations and modifications may be made without departing from the scope of the invention as defined in the appended claims.

Claims

1. A method for communication, comprising: Determining, by a user equipment in a wireless network, that the user equipment has been configured with one or more carriers, and that the one or more carriers are to be used as secondary cell carriers in the wireless network; The user equipment detects that a cell satisfies one or more predefined conditions; In response to the user equipment using the selected one of the one or more carriers as the selected secondary cell carrier, detecting that a cell on the selected secondary cell carrier satisfies the one or more predefined conditions, performing access to the cell to request the cell to become a secondary cell for the user equipment; determining whether data buffering in the user equipment exceeds a first threshold or determining that the wireless network has indicated to the user equipment that data buffering at the wireless network has exceeded a second threshold, wherein performing the request for the cell to become a secondary cell is performed in a manner as follows: in response to determining that the data buffering in the user equipment exceeds the first threshold or determining that the wireless network has indicated to the user equipment that the data buffering at the wireless network has exceeded the second threshold, and wherein determining whether data buffering in the user equipment exceeds the first threshold is performed in a manner as follows: in response to a current data transmission from the user equipment to the primary cell being an ongoing transmission, or having been previously initiated or started but not yet ongoing, or being scheduled or triggered to start within a period of time or to start immediately; as well as A response is received, by the user equipment, from the cell regarding success of the request for the cell to become the secondary cell for the user equipment.

2. The method of claim 1 , wherein detecting that the cell satisfies one or more predefined conditions is performed in response to a current data transmission from the user equipment to the primary cell being an ongoing transmission, or previously initiated or started but not yet ongoing, or scheduled or triggered to start within a period of time or to start immediately.

3. The method of claim 1 , wherein detecting that the cell satisfies one or more predefined conditions comprises determining that a measurement from the cell is better than a given threshold, wherein before the user equipment transitions to an idle / inactive state, the user equipment is configured with a list of carriers to measure while in the inactive / idle state, and wherein the method further comprises: The user equipment measures carriers in the list while the user equipment is in the inactive / idle state and uses the measurements for performing the request for the cell in response to transitioning to a connected mode with a primary cell in the wireless network.

4. The method according to claim 1, wherein the detecting that the cell satisfies one or more predefined conditions comprises: It is determined that the cell is detectable and that a cell identity of the cell belongs to a list of cell identities indicated by a wireless network to the user equipment.

5. The method according to claim 1, further comprising: A request issued by a wireless network is received, the request issued by the wireless network being used to perform a request for the user equipment to add any secondary cell as a secondary cell for the user equipment, and wherein performing the request for the cell to become the secondary cell is performed in response to the request issued by the wireless network. 6 . The method according to claim 1 , wherein the secondary cell is a primary secondary cell, and the request for the cell to become a secondary cell for the user equipment is a request for the cell to become the primary secondary cell for the user equipment.

7. The method of claim 1, wherein the request for the cell to become a secondary cell for the user equipment is used to allow the user equipment to participate in dual connectivity or carrier aggregation between the user equipment, at least one secondary cell and a primary cell in the wireless network.

8. A method for communication, comprising: receiving, at a cell in a wireless network, on a carrier, a random access procedure initiated by a user equipment to request the cell to become a secondary serving cell for the user equipment, the cell satisfying one or more predefined conditions detected by the user equipment; as well as Indicating, by the cell, to the user equipment that the request for the cell to become a secondary cell for the user equipment is successful; wherein the requesting the cell to become a secondary serving cell for the user equipment is performed in response to determining that data buffering in the user equipment exceeds a first threshold or determining that the wireless network has indicated to the user equipment that data buffering at the wireless network has exceeded a second threshold, and wherein determining whether the data buffering in the user equipment exceeds the first threshold is performed in response to a current data transmission from the user equipment to the primary cell being an ongoing transmission, or previously initiated or started but not yet ongoing, or scheduled or triggered to start within a period of time or to start immediately.

9. The method according to claim 8, further comprising: In response to the receiving and the indicating, one or more actions are performed to serve as the secondary cell for the user equipment.

10. The method of claim 9, wherein performing one or more actions further comprises: Sending, by the cell in the wireless network, a request for adding a secondary cell to a primary cell; as well as In response to receiving a primary-secondary cell addition confirmation from the primary cell, the serving as the secondary cell for the user equipment is performed.

11. The method of claim 9, wherein performing one or more actions further comprises sending, by the cell to the user equipment, one or more parameters for the secondary cell, the one or more parameters enabling the user equipment to access the secondary cell.

12. The method according to claim 8, wherein the secondary cell is a primary secondary cell, and the request issued by the user equipment for the cell to become a secondary cell for the user equipment is a request for the cell to become the primary secondary cell for the user equipment.

13. An apparatus for communication, comprising: at least one processor; as well as at least one memory including computer program code, The at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to perform operations comprising: Determining, by a user equipment in a wireless network, that the user equipment has been configured with one or more carriers, and that the one or more carriers are to be used as secondary cell carriers in the wireless network; The user equipment detects that a cell satisfies one or more predefined conditions; In response to the user equipment using the selected one of the one or more carriers as the selected secondary cell carrier, detecting that a cell on the selected secondary cell carrier satisfies the one or more predefined conditions, performing access to the cell to request the cell to become a secondary cell for the user equipment; determining whether data buffering in the user equipment exceeds a first threshold or determining that the wireless network has indicated to the user equipment that data buffering at the wireless network has exceeded a second threshold, wherein performing the request for the cell to become a secondary cell is performed in response to determining that the data buffering in the user equipment exceeds the first threshold or determining that the wireless network has indicated to the user equipment that the data buffering at the wireless network has exceeded the second threshold, and wherein determining whether data buffering in the user equipment exceeds the first threshold is performed in response to a current data transmission from the user equipment to the primary cell being an ongoing transmission, or previously initiated or started but not yet ongoing, or scheduled or triggered to start within a period of time or to start immediately; and A response is received, by the user equipment, from the cell regarding success of the request for the cell to become the secondary cell for the user equipment.

14. The apparatus of claim 13, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to perform detecting that the cell satisfies one or more predefined conditions in the following manner: in response to a current data transmission from the user equipment to the primary cell being an ongoing transmission, or previously initiated or started but not yet ongoing, or scheduled or triggered to start within a period of time or to start immediately. 15 . The apparatus according to claim 13 , wherein the secondary cell is a primary secondary cell, and the request for the cell to become a secondary cell for the user equipment is a request for the cell to become the primary secondary cell for the user equipment.

16. An apparatus for communication, comprising: at least one processor; as well as at least one memory including computer program code, The at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to perform operations comprising: receiving, at a cell in a wireless network, on a carrier, a random access procedure initiated by a user equipment to request the cell to become a secondary cell for the user equipment, the cell satisfying one or more predefined conditions detected by the user equipment; and Indicating, by the cell, to the user equipment that the request for the cell to become a secondary cell for the user equipment is successful; wherein the requesting the cell to become a secondary serving cell for the user equipment is performed in response to determining that data buffering in the user equipment exceeds a first threshold or determining that the wireless network has indicated to the user equipment that data buffering at the wireless network has exceeded a second threshold, and wherein determining whether the data buffering in the user equipment exceeds the first threshold is performed in response to a current data transmission from the user equipment to the primary cell being an ongoing transmission, or previously initiated or started but not yet ongoing, or scheduled or triggered to start within a period of time or to start immediately.

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