Method, apparatus and computer program

Abstract

An apparatus, e.g. user equipment (UE) 312, stores information of a list of cells, the list of cells comprising a primary cell and one or more secondary cells, and associates at least one combination

Description

TECHNICAL FIELD

[0001] Various examples of this disclosure relate to a method, apparatus, system, user equipment and computer program, and in particular, but not exclusively, to utilisation of telecommunication carriers. BACKGROUND

[0002] A communication network can be seen as a facility that enables communications between two or more communication devices or provides communication devices access to a data network. A mobile or wireless communication network is one example of a communication network. A communication device may be provided with a service by an application server.

[0003] Such communication networks operate in accordance with standards, such as those provided by 3GPP (Third Generation Partnership Project) or ETSI (European Telecommunications Standards Institute). Examples of standards provided by 3GPP include the so-called 3GPP standards for cellular technology generations, such as 3GPP standards for 4G technology and 3GPP standards for 5G technology. SUMMARY

[0004] Some examples of this disclosure will be described with respect to certain aspects. These aspects are not intended to indicate key or essential features of the various examples of this disclosure, nor are they intended to be used to limit the scope of thereof. Other features, aspects, and elements will be apparent to a person skilled in the art in view of this disclosure. For example, it should be appreciated that further aspects may be provided by the combination of any two or more of the various aspects described below.

[0005] According to a first aspect there is provided a user equipment comprising at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the user equipment at least to perform: storing information of a list of cells, the list of cells comprising a primary cell and one or more secondary cells, and associating at least one combination of cells from the list of cells with a carrier switching pattern; indicating capabilities of the user equipment to operate with a first carrier aggregation combination and a second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern; when the user equipment is using the first carrier aggregation combination and in response to an instruction received at the user equipment to connect to the at least one combination of cells that is associated with the carrier switching pattern, transitioning the user equipment from using the first carrier aggregation combination to using the second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern and the carrier switching pattern causes the user equipment to switch between a first carrier and a second carrier.

[0006] According to a second aspect there is provided an apparatus comprising means for performing: storing information of a list of cells, the list of cells comprising a primary cell and one or more secondary cells, and associating at least one combination of cells from the list of cells with a carrier switching pattern; indicating capabilities of the user equipment to operate with a first carrier aggregation combination and a second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern; using the first carrier aggregation combination and in response to an instruction received at the user equipment to connect to the at least one combination of cells that is associated with the carrier switching pattern, transitioning the user equipment from using the first carrier aggregation combination to using the second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern and the carrier switching pattern causes the user equipment to switch between a first carrier and a second carrier.

[0007] According to a third aspect there is provided an apparatus comprising: storing circuitry configured to perform storing information of a list of cells, the list of cells comprising a primary cell and one or more secondary cells, and associating at least one combination of cells from the list of cells with a carrier switching pattern; indicating circuitry configured to perform indicating capabilities of the user equipment to operate with a first carrier aggregation combination and a second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern; using circuitry configured to perform using the first carrier aggregation combination; transitioning circuitry configured to perform, in response to an instruction received at the user equipment to connect to the at least one combination of cells that is associated with the carrier switching pattern, transitioning the apparatus from using the first carrier aggregation combination to using the second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern and the carrier switching pattern causes the user equipment to switch between a first carrier and a second carrier.

[0008] According to a fourth aspect, there is provided a method performed by a user equipment, comprising storing information of a list of cells, the list of cells comprising a primary cell and one or more secondary cells, and associating at least one combination of cells from the list of cells with a carrier switching pattern; indicating capabilities of the user equipment to operate with a first carrier aggregation combination and a second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern; using the first carrier aggregation combination and in response to an instruction received at the user equipment to connect to the at least one combination of cells that is associated with the carrier switching pattern, transitioning the apparatus from using the first carrier aggregation combination to using the second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern and the carrier switching pattern causes the user equipment to switch between a first carrier and a second carrier.

[0009] According to a fifth aspect there is provided a computer program comprising instructions which, when executed by a user equipment, cause the user equipment to perform at least the following: storing information of a list of cells, the list of cells comprising a primary cell and one or more secondary cells, and associating at least one combination of cells from the list of cells with a carrier switching pattern; indicating capabilities of the user equipment to operate with a first carrier aggregation combination and a second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern; using the first carrier aggregation combination and in response to an instruction received at the user equipment to connect to the at least one combination of cells that is associated with the carrier switching pattern, transitioning the user equipment from using the first carrier aggregation combination to using the second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern and the carrier switching pattern causes the user equipment to switch between a first carrier and a second carrier.

[0010] According to a sixth aspect there is provided a non-transitory computer readable medium comprising instructions which, when executed by a user equipment, cause the user equipment to perform at least the following: storing information of a list of cells, the list of cells comprising a primary cell and one or more secondary cells, and associating at least one combination of cells from the list of cells with a carrier switching pattern; indicating capabilities of the user equipment to operate with a first carrier aggregation combination and a second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern; using the first carrier aggregation combination and in response to an instruction received at the user equipment to connect to the at least one combination of cells that is associated with the carrier switching pattern, transitioning the user equipment from using the first carrier aggregation combination to using the second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern and the carrier switching pattern causes the user equipment to switch between a first carrier and a second carrier.

[0011] Some further features are provided according to the following statements. It will be appreciated that each of these statements may apply to any of the first to sixth aspects provided above.

[0012] The user equipment further caused to store an implementation, and to use the implementation to determine when to check for the switching pattern and to check the identity of the carriers to which the switching pattern is to be applied.

[0013] The check of the identity of the carriers to which the switching pattern is to be applied includes checking that those carriers include at least one supplementary downlink carrier.

[0014] The supplementary downlink carrier comprises a frequency division duplexing carrier.

[0015] The user equipment is further caused to react to activation and / or de-activation of the primary cell and / or one or more secondary cells, and to selectively activate and de-activate the switching pattern accordingly.

[0016] The user equipment is further caused to obtain, from one or more media access control messages received at the user equipment, information of the activation and / or de-activation of the primary cell and one or more secondary cells.

[0017] The user equipment further caused to activate the switching pattern based on the activation and / or de-activation of the one or more secondary cells.

[0018] The user equipment further caused to monitor an impact of the switching pattern on the one or more secondary cells.

[0019] The monitoring an impact of the switching pattern comprises performing cell measurements on the one or more secondary cells.

[0020] The first and second carriers of the second carrier aggregation combination comprise low-band carriers.

[0021] The second carrier of the second carrier aggregation combination comprises a supplementary downlink carrier.

[0022] The first carrier aggregation combination comprises at least one carrier that is not a low-band carrier.

[0023] When using the first carrier aggregation combination the user equipment utilises one or more carriers that operate in a continuous fashion without switching.

[0024] In the second carrier aggregation combination at least one further carrier remains available in a continuous manner, in addition to the first and second carriers.

[0025] The transitioning the user equipment from the first carrier aggregation combination to the second carrier aggregation combination occurs whilst the apparatus remains connected to the primary cell and is moving towards a cell edge of the primary cell.

[0026] The transitioning the apparatus from the first carrier aggregation combination to the second carrier aggregation combination occurs in response to the user equipment moving, in relation to the primary cell, from a near field region to a far field region via a transition field region, and the user equipment is caused to activate the second carrier aggregation combination when moving from the transition field region to the far field region.

[0027] When moving back from the far field region to the transition field region the user equipment is configured with the first carrier aggregation combination.

[0028] In the above, many different aspects have been described. As previously noted, it should be appreciated that further aspects may be provided by the combination of any two or more of the aspects described above. Other features, aspects, and elements will become apparent in view of the following. DESCRIPTION OF FIGURES

[0029] Some examples will now be described, by way of non-limiting and illustrative example only, with reference to the accompanying Figures (FIGs.) in which:

[0030] FIG. 1 shows an example of a communication network to which examples disclosed herein may be applied;

[0031] FIG. 2 is a schematic block diagram illustrating a user equipment, a communication network, and a data network in accordance with an example implementation;

[0032] FIG. 3 schematically shows a typical multi-band scenario;

[0033] FIG. 4 schematically shows a secondary cell de-activation scheme in different regions, in a multi-band scenario, according to some examples;

[0034] FIG. 5 schematically shows a concept of mode switching dependent on cell distance, according to some examples;

[0035] FIG. 6 schematically shows a cell configuration strategy, according to some examples;

[0036] FIG. 7 schematically shows carrier interruptions, according to four example scenarios;

[0037] FIG. 8 schematically shows a signalling diagram according to some examples;

[0038] FIGS. 9 to 11 are method flow charts schematically showing some methods according to some examples;

[0039] FIG. 12 schematically shows some features of a telecommunications apparatus, according to some examples. DETAILED DESCRIPTION

[0040] Some examples of this disclosure may be implemented in a communication network, such as any of the following radio access technologies (RATs): World-wide Interoperability for Micro-wave Access (WiMAX), Global System for Mobile communications (GSM, 2G), GSM EDGE radio access Network (GERAN), General Packet Radio Service (GRPS), Universal Mobile Telecommunication System (UMTS, 3G) based on basic wideband-code division multiple access (W-CDMA), high-speed packet access (HSPA), Long Term Evolution (LTE), LTE-Advanced, and enhanced LTE (eLTE), 5G (also called NR), or any future RAT such as 6G. Moreover, communication within the communication network may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiple (OFDM), and / or Discrete Fourier Transform spread OFDM (DFT-s-OFDM).

[0041] As used herein, the term “network device” or “network node” may refer to a node in a communication network via which user equipment may access the network and / or which is capable of controlling radio communication and managing radio resources within a cell. The network node or network device may be referred to as a base station (BS), an access point (AP) or an access node. The network device may be, depending on the applied technology, for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio head (RH), a remote radio head (RRH), a relay, an Integrated Access and Backhaul (IAB) node, a low power node, a nonterrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, or an aircraft network device.

[0042] The term “terminal device” may refer to any end device that may be capable of wireless communication. By way of example, a terminal device may be referred to as a communication device, user equipment (UE), a Subscriber Station (SS), or a Mobile Station (MS). The terminal device may include a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and play-back appliances, vehicle-mounted wireless terminal devices, USB dongles, an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like.

[0043] A term “resource”, as used herein, may refer to radio resources in time domain, in frequency domain, in space domain, and / or in code domain. Some examples of resources include, e.g., a physical resource block (PRB), a radio frame, a subframe, a time slot, a subband, a frequency region, a sub-carrier, a beam, etc. The term “transmission” and / or “reception” may refer to wirelessly transmitting and / or receiving via a wireless propagation channel on radio resources.

[0044] FIG. 1 illustrates an example of a communication network to which examples disclosed herein may be implemented. The communication network or a cellular communication network may comprise a network node 110 providing one or more cells, such as cell 100, and a network node 112 providing one or more other cells, such as cell 102. Each cell may be, e.g., a macro cell, a micro cell, femto, or a pico cell, for example. The cell may define a coverage area or a service area of the corresponding access node.

[0045] The network node 110 may provide a user equipment (UE) 120 (one or more UEs) with wireless access to the communication network. The wireless access may comprise downlink (DL) communication from the network node to the UE 120 and uplink (UL) communication from the UE 120 to the network node. Examples of uplink channels comprise physical uplink control channel (PUCCH) for transmitting control information and physical uplink shared channel (PUSCH) for transmitting data towards the network. Examples of downlink channels comprise physical downlink control channel (PDCCH) for transmitting control information and physical downlink shared channel (PDSCH) for transmitting data towards the user equipment.

[0046] There may be a plurality of UEs 120, 122 in the system. Each UE may be served by the same or by different network nodes 110, 112. A UE may be configured with dual connectivity (DC), wherein the UE, e.g. UE 120, may be connected to multiple network nodes 110, 112. The UEs 120, 122 may communicate with each other, in case device-to-device (D2D) communication interface is established between them via a so-called sidelink (SL). Such D2D communications may be referred to as machine-to-machine, peer-to-peer (P2P) communications, or vehicle-to-vehicle (V2V), for example.

[0047] In the case of multiple network nodes in the communication network, the network nodes may be connected to each other via an interface. LTE specifications call such an interface as X2 interface. An interface between an LTE node and a 5G node, or between two 5G nodes may be called Xn interface. The network nodes 110 and 112 may be further connected via another interface to a core network 116 of the communication network.

[0048] In the following, various examples are explained with reference to communication devices capable of communication with a communication system. Before explaining in detail the various examples of this disclosure, a 5th generation communication system (5GS), an access network and a core network (5GC) thereof, and communication devices are briefly explained with reference to FIG. 2.

[0049] FIG. 2 shows a schematic representation of a communication system. Referring to FIG. 2, user equipment (UE) 200 that communicates with application servers (not shown) hosting third party application functions (not shown) of a data network 202 via a communication network is shown. The communication network includes a radio access network 206 (e.g., a Next Generation Radio Access Network (NG-RAN)) and a core network 208 (e.g., a 5G core network (5GC)) that operate based on the 5th generation radio access technology described, for example, in the 3rd Generation Partnership Project (3GPP) standard for new radio. The core network 208 includes network functions (generally referred to a network function and collectively referred to as network functions) may be connected to a management system configured to manage the communication network as described in further detail below.

[0050] Radio access network 206 comprises one or more radio access network (RAN) nodes (otherwise referred to as base stations). A RAN node may provide one or more cells. A cell may be, for example, a macro cell, a micro cell, femto, or a pico cell. A cell defines a coverage area or a service area of a RAN node. A RAN node may be, for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), a next generation node B (gNB), a Remote Radio Unit (RRU), a remote radio head (RRH), a relay, an Integrated Access and Backhaul (IAB) node, a low power node. RAN nodes may be deployed in non-terrestrial network (NTN) devices, such as satellites (e.g., low earth orbit (LEO) satellites or geosynchronous earth orbit (GEO) satellites), aircrafts, or drones, where such NTN devices form a non-terrestrial network, such as a ground station. RAN nodes may also be deployed on the group in which case the RAN nodes may be referred to as terrestrial network device. A RAN comprising terrestrial network devices is generally referred to as a terrestrial network.

[0051] A RAN node may have a split architecture where functions of the RAN node (e.g., an eNB or a gNB) are split between various entities. A RAN node that has a split architecture may comprise a radio unit (RU) (otherwise referred to as a remoter radio read (RRH), a centralized unit (CU) and one or more distributed units (DUs). A DU may be connected to a RU via a fronthaul. A DU may be connected to a CU via a midhaul or F1 interface. A CU may be connected to a core network (e.g., core network 108) via a backhaul. In a RAN node with a split architecture, operations of the RAN node may be carried out, by the CU, the DU. One CU may control one or more DUs.

[0052] A RU converts radio signals sent to and from an antenna into a digital signal for transmission over packet network, handles the digital front end (DFE) and the lower PHY layer, and includes digital beamforming functionality. A DU is a logical entity (e.g., software) that is hosted and run on a server located near an RU. A CU is a logical entity (e.g., software) that is hosted and run on a server. The CU may be hosted and run on its own server or may be hosted and run on the same server that hosts and runs the DU located near an RU. The DU includes a subset of the functions of a RAN node (e.g., eNB or gNB) depending on the split of functions and the CU includes the other functions of a RAN node that are not in the subset of functions of the DU. A DU may comprise a subset of the layers of a protocol stack of a RAN node and a CU may comprise the other layers of the protocol stack that are not in the subset of layers in the DU. For example, in some implementations, a DU may include a radio link control (RLC) layer, a medium access control (MAC) layer and a physical (PHY) layer of a protocol stack for a RAN node, whereas a CU may comprise the layers of the protocol stack of a RAN node above the RLC layer, such as a packet data convergence protocol (PDCP) layer, a radio resource control (RRC) layer and an internet protocol (IP) layer. The operations of a DU are controlled by a CU.

[0053] The core network 208 may have a service-based architecture. The network functions of the core network 208 include an access and mobility function (AMF), an authentication server function (AUSF), a network exposure function (NEF), a network repository function (NRF), a network slicing selection function (NSSF), a policy control function (PCF), a session management function (SMF), a user plane function (UPF), a united data repository (UDM), and a network data analytics function (NWDAF). Other network functions of the core network 208, such as a binding support function (BSF), a charging function (CHF), are not shown in FIG. 2 for ease of illustration.

[0054] The AMF handles access, authorization, authentication of user equipment, including the UE 200 and manages the mobility of user equipment 200 as the user equipment 200 moves between different radio access networks, cells, or locations.

[0055] The SMF is responsible for establishing, maintaining, and terminating protocol data unit sessions in the core network 208. The SMF manages user plane resources and interacts with the UPF of the core network 208 to ensure data packets are correctly routed and forwarded.

[0056] The UDM performs authentication procedures, stores and manages user data, including such as subscriber profiles, authentication credentials, and authorization policies, implements security mechanisms to protect user data and resources of the communication network (e.g., the core network208) from unauthorized access attacks and vulnerabilities, and interacts with other network functions of the core network 208, such as the PCF, to enforce access control policies, Quality of Service (QoS) parameters, and service restrictions based on user profiles and subscription plans. The UDM is also responsible for managing the registration of network functions that serve the user equipment 200.

[0057] The network analytics data function (NWAF) is configured to collect or retrieve data about one or more NFs of the core network, generate analytics based on the data about the one or more NFs collected or retrieved by the NWDAF, and to provide the analytics that are generated to itself or to other NFs that have requested analytics generated by the NWADF. The NWDAF may include an Analytics logical function (AnLF) that is configured to generate analytics (e.g., generate statistics and / or generate predictions) based on the data about the one or more NFs collected and / or retrieved by the NWDAF. The NWDAF further includes an analytics service that is exposed by the NWDAF to provide the analytics generated by the AnLF. The NWDAF further includes a Model Training logical function (NWDAF(MTLF)) that is configured to train AI / ML models that can be used by AnLF to generate analytics based on the data about the one or more network functions collected or retrieved from the one or more network functions and / or the OAM entity.

[0058] The functionalities of other network functions of the core network 208 are not further described in detail.

[0059] The present application aims to address challenges regarding the use of low-band carriers.

[0060] A challenge of mid-band versus low-band is shown in Figure 3 which schematically shows an environment 330 in which the present disclosure may take effect. The amount of mid-band spectrum that an operator holds may be 10 to 20 times greater than the amount of low-band spectrum. Mid-band spectrum 332 is useful closer to sites (e.g. closer to a base station or cell 310), whereas low-band spectrum propagates farther making it more useful further away from sites. The low-band spectrum carries a lower traffic volume percentage in urban (indoor) and rural areas whereas the main traffic volume in urban areas is in the midband spectrum. In rural areas, the split is more equal in traffic volume between low-bands and mid-bands. Therefore there is a shift in which spectrum that is used when moving away or to a cell centre, if the edge of the cell is in a rural area.

[0061] Low bands are of frequencies less than 1GHz, while mid bands are frequencies of more than 1.7GHz when defined from an operator point of view.

[0062] The topic is discussed in “New WID on low band carrier aggregation via switching” (RP-243317 NR_LBCA_Sw_WID) which states that an enhancement of the 3GPP specification is needed to enable the following solution: “Device needs to support switching: when the SCell operation is triggered, UE needs to switch to the SCell, and during the operation period there is no simultaneous Tx / Rx between the PCell and the Scell. Device switches back to the PCell after the SCell operation is finished”. In the context of this discussion, it relates to the PCell and the Scell both being located in the low-band range. These switch states are then defined as the following cases: “Case 1: Tx / Rx on FDD carrier 1 and no Rx on SDL carrier 2; Case 2: Rx on SDL carrier 2 and no Tx / Rx on FDD carrier 1”.

[0063] The present application identifies a technical problem which is that transitions between configurations of carriers includes reconfigurations managed by the network. The Radio resource control (RRC) messages will interrupt and load the network with traffic, not creating value for data traffic. Since the low band carrier aggregations of the WID study are two-band combinations, all of which are new FDD-SDL combinations in the low-band frequency range, then there is also the problem that the network (NW) will have to signal new RRC_Reconfiguration messages to every UE that enters or exits the regions 336, 338, 340 shown in Figure 3, for accessing the mid-band carriers, causing significant overhead in signaling new configurations.

[0064] Taking into account these problems identified by the present application, the present application proposes activation of a carrier switching pattern while having more carriers (i.e. further carriers in addition to the switching carriers) configured and active. As will be discussed in more detail below, a UE is configured with a list of cells, not limited to two-band combinations. For example, the list contains a list of cells that are available for the UE to connect to, for example dependent upon location of the UE and signal strength of those cells in the list. In examples, at least one combination of cells will activate a carrier switching pattern for the UE. In other words, certain cell combinations may be associated with a carrier switching pattern. The cells for the UE to connect to, and thus the combination of cells, may be activated by the network. If the network doesn’t activate the combination that requires or activates carrier switching, the UE and network operate without carrier switching. Once the network sends a cell activation command containing a combination of cells that require or activate carrier switching, the UE and network operate with carrier switching. Carrier switching may reduce congestion on each of the carriers that is involved with the switching (compared to not implementing switching and passing all traffic through one carrier). Carrier activation and deactivation will also reduce congestion, since the carriers have more space for data, as the RRC_Reconfiguration messages are skipped.

[0065] Table 1 below, which is an extract from 3GPP TS38.101, shows some known carrier aggregation combinations, that includes specifically the 5G bands n5 and n29, which are a focus of the study. It shows that these bands are present in combinations of more than two carriers, the third carrier being a mid-band carrier. NRCA configuration Uplink CA configuration or single uplink carrier NR Band Channel bandwidth (MHz) Bandwidth combination set CA_n5A-n25A-n29A CA_n5A-n25A n5 5, 10, 15, 20 0 n25 5, 10, 15, 20, 25, 30, 40 n29 5, 10 CA_n5A-n29A-n66A CA_n5A-n66A n5 5, 10, 15, 20 0 n29 5, 10 n66 5, 10, 15, 20, 25, 30, 40 CA_n5A-n29A-n77A n77 CA_n5A-n77A n5 5, 10, 15, 20 0 n29 5, 10 n77 10, 15, 20, 25, 30, 40, 50, 60, 70, 80, 90, 100 Table 1

[0066] In the present application it is proposed that higher order combinations (i.e. greater 10 number of combined carriers) are used and assigned while the UE has coverage of the mid band (e.g. n25, n66 and n77 of the table above), which holds multiple carriers, also beyond the switching pair in low-band. Once the UE is configured with serving cells for these carriers, the NW applies MAC CE Scell activation and deactivation to manage the UE mode of operation. The Scell activation-deactivation doesn’t involve RRC reconfigurations. However, 15 the Scell activation / deactivation wouldn’t automatically make the UE aware of the mode of operation.

[0067] In the present application it is proposed that for higher order combinations the NW may signal to the UE to apply a switched operation (i.e. carrier switching) when the combination of active cells require or are associated with the switched operation. For example, a certain Pcell+Scells combination may activate the carrier switching operation. For example, switching may occur between the n5 and n29 carriers during carrier aggregation of those carriers (CA_n5A-n29A).

[0068] According to examples, when the UE is on the cell edge, and the UE is served by the switched carriers, the UE will still be configured by the NW to perform periodic measurements of the deactivated Scell(s). This may assist with subsequent reactivation of that deactivated Scell if required (e.g. moving back towards that Scell).

[0069] Secondary cell activation / deactivation and carrier utilization is explained with reference to Figure 4, which schematically shows a UE 312 which can move between regions closer to the cell 310 (e.g. regions 336 and 338) and regions further from the cell e.g. region 340. Region 336 may be an urban area, and may be termed a near-field region. Region 338 may be termed a transition field region. Region 340 may be a rural area and may be termed a far-field region or a cell-edge region.

[0070] As shown schematically in Fig. 4, carriers may be selected based on active Scell(s). In Figure 4 (bottom left and bottom right) de-activated carriers are represented with underline. In some examples, n29A is a supplementary downlink (SDL) carrier with no uplink capability. For example, in the near-field region 336 three carrier aggregation combinations may be available to the UE 312: CA_n5A-n25A (n29A inactive) CA_n5A-n66A (n29A inactive) CA_n5A-n77A (n29A inactive)

[0071] Likewise, in the far-field region 340 three carrier aggregation combinations may be available to the UE 312: CA_n5A-n29A (n25A inactive) CA_n5A-n29A (n66A inactive) CA_n5A-n29A (n77A inactive)

[0072] In one example the UE 312 moves back towards the centre of the cell i.e. back towards base station 310, from far-field region 340. Upon receiving mid-band coverage, the NW reactivates the mid-band carrier, while de-activating the supplementary downlink band (n29A). So in this example the configuration is all relevant bands, but the set of activated cells is as indicated. So, in this case the configuration could be CA_n5A-n29A-n66A, where the carriers on band 5 and 66 are active in cell centre and the carriers on band 5 and 29 are active at cell edge. In between the cell centre and the cell edge all bands may actually be active, in some examples The change in Scell activation will trigger UE signaling to exit the switched operation state, if the UE 312 was in switched operation state or mode when in far-field region 340.

[0073] According to the present application, one configuration strategy for a UE 312 supporting low-band carrier aggregation (LBCA) is shown in Figure 5. Again, inactive carriers are represented with underline.

[0074] In Figure 5, the UHB (ultra high band, UE band group definition), HB (high band, UE band group definition) and MB (mid-band, UE band group definition) bands have good coverage in the near field 336, HB and MB in the transition field 338 and in the rural area 340, where the LBCA switching feature becomes advantageous as these are carrying 50% of the traffic on low-bands .

[0075] However, there is a technical problem in the boundary between the transition field 338 and the rural area 340, in that the only overlap between the two fields is the root low band, band n5. This could result in a drop of average bit rate for the user.

[0076] Therefore, the present application has identified that it is advantageous establishing the additional support of band n29. n29 may be an SDL carrier. A switching pattern between bands n5 and n29 (for example) may therefore be established before disabling or inactivating other bands that were being used in the transition field 338 (e.g. inactivating n25 and / or n66, but only once the switching pattern has been established).

[0077] For this reason, in some examples the UE 312 is configured to maintain at least one of the other carriers (mid / high band carrier which does not require switching) while entering the far-field region 340, in addition to the two switching band carriers. “Maintaining” at least one of the other carriers may be considered that the at least one of the other carriers (which may also be referred to as a further carrier) is kept available so that it can be activated quickly, for example when sufficient power returns.

[0078] Since in some examples the UE may support either CA_n5A-n29A in a concurrent operational state or it may support CA_n5A-n29A only in a switched mode of operation the transition region 338 may face two different configuration cases of the UEs, referred to as Case A and Case B below. In both cases below, the primary cell (Pcell) is n5. Case A

[0079] UEs supporting the concurrent CA operation could use Scell activation and deactivation between the bands different to n5 (PCell). It should be noted that n5 and n29 may also be Scells. Case B

[0080] UEs supporting the switched operation could also use Scell activation and deactivation between the bands different to n5 (PCell), but at the same time transition to and from the switched mode of operation on the PCell when the SDL band is activated, and back to normal FDD (Frequency Division Duplexing) operation when the n29 SDL Scell is deactivated.

[0081] According to some examples, how the gNB 310 and UE 312 negotiates the proper operation may rely on the UE 312 declaring or signalling its capabilities to the gNB 312. For example, UE 312 may declare its support for the FDD-SDL operation in the LB. When the UE 312 declares switched mode support, only the gNB 310 and UE 312 will engage this switched pattern upon Scell activation commands (MB / HB / UHB vs. SDL Scell). This may eliminate the need for RRC reconfigurations to swap the configurations all together.

[0082] Not having to apply RRC reconfigurations, while supporting different types of UEs in the transition field 338 may significantly offload the NW in overhead created by reconfigurations (which may be a very large number of reconfiguration), especially for inbound and outbound traffic in a city.

[0083] Another example is shown with respect to Figure 6, which shows a cell configuration strategy which facilitates fewer gaps in bit-rate during a transition from cell centre to cell edge.

[0084] In the example of Figure 6, in the near field region 336 and transition field region 338 the UE 312 may adopt any of the carrier aggregation combinations shown at 342, i.e. any of: CA_n5A-n25A (n29A inactive) CA_n5A-n66A (n29A inactive) CA_n5A-n77A (n29A inactive)

[0085] It is to be noted that where a carrier (e.g. n29A) is “inactive”, it is still configured and remains part of the configuration, albeit in an inactive state.

[0086] In the example of Figure 6, in the transition field region 338 and far field region 340 the UE 312 may adopt any of the carrier aggregation combinations shown at 344, i.e. any of: CA_n5A-n29A (n25A inactive) CA_n5A-n29A (n66A inactive) CA_n5A-n29A (n77A inactive)

[0087] Again, in Figure 6 the inactive carriers are represented with underline.

[0088] An example of switching two carriers, while two other carriers are active is shown in the chart on the bottom right of Figure 6. As shown the n25 and n29 carriers switch, such that when the n5 carrier is active the n29 carrier is inactive, and when the n5 carrier is inactive the n29 carrier is active. In other words, it may be considered that the n5 and n29 carriers alternate their activity. The two other carriers n25 and n66 remain active while the n5 and n29 carriers adopt their switching pattern. It will also be noted that the switching pattern may be causing interruptions on other carriers (n25 and n66 in this case) than the switching FDD-SDL switching pair of carriers (n5 and n29 in this case). As explained previously above, the UE 312 may adopt this switching pattern when the UE 312 is commanded or instructed by the NW to adopt a cell combination (Scell(s) combination) from a list that is configured to cause the UE to adopt the switching pattern.

[0089] Figure 7, as discussed below, shows in more detail the impact of interruptions between switching carriers and non-switching carriers. In the example of Figure 7, the switching carriers are n5 and n29, and the non-switching carriers are one or more of n25, n66, n77.

[0090] Figure 7 illustrates the potential impact of interruptions between the switching carriers and non-switching carriers. The interruptions may be considered internal interruptions at the UE 312, for example interruptions of Tx and / or Rx data symbols. Four examples (i) to (iv) are shown in Figure 7, summarised as follows:

[0091] (i) Switching carriers n5 and n29, additional non-switching carriers n25 and n66, interruptions caused by switching experienced by carriers n25 and n66.

[0092] (ii) Switching carriers n5 and n29, additional non-switching carriers n25 and n66, interruptions caused by switching experienced by carrier n25, no interruption experienced by carrier n66.

[0093] (iii) Switching carriers n5 and n29, additional non-switching carriers n25 and n66, interruptions caused by switching experienced by carrier n66, no interruption experienced by carrier n25.

[0094] (iv) Switching carriers n5 and n29, additional non-switching carriers n25 and n66, no interruption experienced by carriers n25 and n66.

[0095] According to some examples, the UE 312 is configured to inform the network of the UE’s capabilities with respect to interruptions between switching and non-switching carriers. In other words, the UE 312 may inform the network of an interruption behaviour. For example, the UE 312 may be configured to report to the NW which non-switching carriers experience interruptions caused by the switching carriers. For example the information of UE’s capabilities with respect to interruptions may comprise information that the additional (non-switching) carrier does not experience the data interruptions when the UE 312 has indicated that no interruptions are needed for operation with the first and second (switching) carriers and the additional (non-switching) carrier(s). Or, the information of UE’s capabilities with respect to interruptions may comprise information that the additional (non-switching) carrier does experience the data interruptions when the UE 312 has indicated that interruptions are needed for operation with the first and second (switching) carriers and the additional (nonswitching) carrier(s).This enables the network to make an informed decision about which nonswitching carrier(s) to select (e.g. ones without interruptions). This may help improve data rates.

[0096] Figure 8 is a signalling diagram showing communications between a UE 812, which may be considered equivalent to UE 120 in Figure 1 and UE 312 in Figure 4 and network (NW) 850, which may be considered equivalent to network 110 in Figure 1, and a network 310 in Figure 4. In this example the NW comprises a Pcell 810, a first secondary cell ScelU shown at 852 and a second secondary cell Scell2 shown at 854. The signalling diagram in Figure 8 shows how activation and deactivation of a carrier (in this case n29) starts and stops the switching pattern.

[0097] The signalling diagram of Figure 8 corresponds to scenario (iv) of Figure 7. Mapping Figure 8 to scenario (iv) of Figure 7, Scell2 854 is considered to be the SDL carrier (i.e. carrier n29), PCell the root FDD carrier in Low-band (i.e. carrier n5) and SCelU is a contiguous carrier (i.e. carrier n25) other than the switched pair. The contiguous carrier (n25) does not experience any interruptions caused by switching between PCell (n5 in this example) and SCell2 (n29 in this example).

[0098] The steps of Figure 8 are set-out below.

[0099] 1. The UE 812 sends information of its capabilities to use a carrier aggregation combination which utilises a carrier switching pattern which switches between a first carrier and a second carrier, to NW 850. More particularly the UE 812 sends information of the UE’s capabilities to use the FDD-SDL LB-LB switched operation to the network 850, more particularly to Pcell 810 of NW 850. This information may also include information of additional carrier(s), besides the two low-band switching carriers, that is / are affected or not affected by the LB-LB switching.

[0100] 2. The PCell 810 is configured for a data connection.

[0101] 3. The PCell 810 engages in active data communication. As can be seen, SCelU 852 and SCell2 854 are not yet configured and therefore are not yet active.

[0102] 4. The RRC connection is re-configured, adding SCelU 852 and SCell2 854 as secondary carriers and configuring the PCell 810 and SCell2 854 to operate in a switched scheme. At this step only PCell 810 is active. Using Figure 7 as an example, the PCell 810 could be on band n5, SCelU 852 on n66 and SCell2 854 on n29.

[0103] 5. The network decides to activate SCelU 852, but not SCell2 854. Compared to Figure 6, the UE 810 may be in the near or transition field and need additional resources. The UE 812 evaluates that because SCell2 854 is NOT activated, there is no reason to enable the switching scheme on the PCell 810.

[0104] 6. The UE 810 has an implementation to be applied, the UE 810 must determine the state when to engage the switched mode operation and to which carriers it must be applied. Determining that the RRC configuration is granted (step 4) with a switched operation, the UE 812 is configured to react to Scell activation / de-activation in a command from the NW 850 (e.g. MAC / CE message) to also potentially change the switched operation of the frontend. In examples, the configuration information of step 1 indicates how every SCell is to behave if the PCell starts to switch. For example the UE is configured with an implementation that triggers in certain CA combinations only when they involve FDD-SDL switched operation. If the UE is in such RRC configured state the UE knows that it must now be observant of MAC / CE instructions on Scell-activation / de-activation, not only to activate and de-activate these, but also when switching to the FDD-SDL state trigger the switched mode operation for these two FDD-SDL carriers, including any of the states (i) to (iv) in Fig.7 for any potential additional Scell. For example, the determining the state when to engage the switched mode operation may comprise checking of the identity of the carriers to which the switching pattern is to be applied, which may include checking that those carriers include at least one supplementary downlink (SDL) carrier. Although this disclosure uses the FDD-SDL as an example where carrier switching is used, the PCell and Scell may also use other types of duplexing combinations, such as FDD-FDD, TDD-TDD, TDD-FDD or others.

[0105] 7. SCelU 852 is now active and there is parallel data communication between the UE 812 and the PCell 810 and SCelU 852.

[0106] 8. The network activates SCell2 854 on top of SCelU 852.

[0107] 9. The UE 810 is configured to now activate the switching pattern between the LB-LB switching pair based on the activation of SCell2 854. In some examples the UE 810 is configured to activate the switching pattern between the LB-LB switching pair based purely on the activation of SCell2 854.

[0108] 10. The UE 812 now starts a switching pattern between PCell 810 and SCell2 854. As seen, the network can still communicate in parallel to SCelU 852 from both switching states, i.e. both if the PCell 810 is active while SCell2 854 is not active, or if the PCell 810 is not active while SCell2 854 is active (see switching pattern in scenario (iv) of Figure 7).

[0109] 11. The network 850, or more particularly PCell 810, now de-activate SCelU 852, whereas SCell2 854 remains active.

[0110] 12. The UE 812 is configured to now determine that the affected SCell (ScelU 852) is not impacting the switching pattern between the LB-LB switching, and remains in the current switched operation engaged at step 8 for the Pcell 810 and Scell2 854.

[0111] 13. PCell 810 and Scell2 854 are now active and there is switched data communication between the UE 812 using the PCell 810 and SCell2 854. In other words, the network 850 can either communicate with the PCell 810 or with the SCell2 854, but not in parallel.

[0112] It will be appreciated that the described apparatus, method and user equipment enables fast activation-deactivation of the switching pattern, without RRC reconfigurations between the regions served by low band or low+mid band.

[0113] Moreover, the disclosure provides a distinction between modes for the UE to use and operate (e.g. LB-LB FDD-SDL CA).

[0114] The disclosure also facilitates transition of UEs with switched operation between transition field region and far-field region, and vice versa, whilst still providing support for UEs with no switching needs

[0115] Also, the disclosure does not apply scheduling restrictions on carriers not needing scheduling restrictions.

[0116] The disclosure also provides a UE implementation to link switched operation from MAC-CE Scell state, to hardware switched operation for affected FDD-SDL carriers.

[0117] Figures 9 to 11 are flow charts of methods, according to some examples.

[0118] With respect to Figure 9, which shows a method performed by an apparatus (such as a UE), at S901 the method comprises storing information of a list of cells, the list of cells comprising a primary cell and one or more secondary cells, and associating at least one combination of cells from the list of cells with a carrier switching pattern.

[0119] At S902 the method comprises using a first carrier aggregation combination, and in response to an instruction to connect to the at least one combination of cells that is associated with the carrier switching pattern, transitioning from using the first carrier aggregation combination to using a second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern and the carrier switching pattern causes the apparatus to switch between a first carrier and a second carrier.

[0120] With respect to Figure 10, which shows a method performed by an apparatus (such as a UE), at S1001 the method comprises connecting with a primary cell and one or more secondary cells.

[0121] At S1002 the method comprises transitioning the apparatus from a first carrier aggregation combination to a second carrier aggregation combination, wherein in the second carrier aggregation combination a carrier switching pattern is utilised between a first carrier and a second carrier whilst a third carrier remains available in a continuous manner, with an interruption behaviour on the third carrier being based on one or more capabilities of the apparatus, the interruption behaviour relating to data interruptions on the third carrier at the apparatus.

[0122] At S1003 the method comprises sending an indication of the interruption behaviour associated with the combination of the first, second and third carriers.

[0123] With respect to Figure 11, which show a method performed by a user equipment, at S1101 the method comprises storing information of a list of cells, the list of cells comprising a primary cell and one or more secondary cells, and associating at least one combination of cells from the list of cells with a carrier switching pattern.

[0124] At S1102 the method comprises indicating capabilities of the user equipment to operate with a first carrier aggregation combination and a second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern.

[0125] At S1103 the method comprises, when the user equipment is using the first carrier aggregation combination and in response to an instruction received at the apparatus to connect to the at least one combination of cells that is associated with the carrier switching pattern, transitioning the apparatus from using the first carrier aggregation combination to using the second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern and the carrier switching pattern causes the apparatus to switch between a first carrier and a second carrier.

[0126] While reference may be made to “an”, “one”, or “some” example(s) throughout this disclosure, this does not necessarily mean that each reference is made to the same example(s), or that a particular feature only applies to a single example. Single features of different examples may also be combined to provide other examples. Further, when a particular feature, structure, or characteristic is described in connection of an example, it is within the knowledge of one skilled in the art to apply such feature, structure, or characteristic in connection with other examples whether or not explicitly described. It shall be understood that although the terms “first,” “second” and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another.

[0127] It is understood that references in the above to various network functions (e.g., to an AMF, an SMF, etc.) may be implemented by apparatus that perform at least some of the functionality associated with those network functions. Further, an apparatus configured to implement a network function may further be configured to implement a virtual network function instance of that network function.

[0128] It should be understood that the apparatuses may comprise or be coupled to other units or modules etc., such as radio parts or radio heads, used in or for transmission and / or reception. Although the apparatuses have been described as one entity, different modules and memory may be implemented in one or more physical or logical entities.

[0129] It is noted that whilst some examples have been described in relation to 5G networks, similar examples can be applied in relation to other networks and communication systems. Therefore, although certain examples were described above by way of example with reference to certain example architectures for wireless networks, technologies and standards, further examples may be applied to any other suitable forms of communication systems than those illustrated and described herein.

[0130] It is also noted herein that there are several variations and modifications which may be made to the various examples described herein without departing from the scope of this disclosure.

[0131] As used herein, the phrases “at least one of A or B”, “at least one of A and B”, and “A and / or B” means (A), (B), or (A and B). For the purposes of the present disclosure, the phrase “A, B, and / or C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C).

[0132] As used herein, the term “or” refers to a non-exclusive “or” unless otherwise indicated (e.g., use of “or else” or “or in the alternative”).

[0133] As used herein, unless stated explicitly, performing a step “in response to A” does not indicate that the step is performed immediately after “A” occurs and one or more intervening steps may be included. Analogously, performing a step or functionality “based on A” does not indicate that the step or functionality is performed solely based on “A” as one or more additional conditions may be included.

[0134] FIG. 12 shows, by way of example, a block diagram of an apparatus 1210. The apparatus 1210 comprises, for example, at least one processor 1212 and at least one memory 1214 storing instructions 1215 that, when executed by the at least one processor, may cause the apparatus 1210 at least to perform the method or methods as disclosed herein. In some examples, the at least one memory and the instructions (e.g., computer program code, software, etc.), are configured, with the at least one processor, to cause the apparatus 1210 to perform the method or methods as disclosed herein.

[0135] A processor 1212 may comprise circuitry, or be constituted as circuitry or circuitries, the circuitry or circuitries being configured to perform phases of methods in accordance with examples described herein. As used herein, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations, such as implementations in analog, digital and / or quantum circuitry, and (b) combinations of hardware circuit(s) and software, such as, as applicable: (i) a combination of analog, digital and / or quantum hardware circuit(s) with software / firmware and (ii) any or all portions of hardware processor(s) (including digital and / or quantum processor(s)), with software, and memory(ies) that work together to cause an apparatus, such as a device, computing device, user equipment, or server to perform various functions) and (c) any or all portions of hardware circuit(s), such as microprocessor(s), processor(s) and / or quantum processor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation. This definition of circuitry applies to all uses of this term in this disclosure, including in any claims. As a further example, as used in this disclosure, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or 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 the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0136] The memory 1214 may be implemented using any suitable data storage technology. The memory may comprise a database for storing data. The memory 1214 may be at least in part external to apparatus 1210 but accessible to apparatus 1210.

[0137] The instructions 1215 may be comprised in a computer readable medium or a non-transitory computer readable medium. A term non-transitory, as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., random access memory, RAM, vs. read only memory, ROM).

[0138] For example, the apparatus 1210 may be a terminal device, such as the UE described previously. As another example, the apparatus may be comprised in such a terminal device (e.g., as a chipset configured to control the terminal device). The apparatus 1210 may be caused or configured to perform at least the method of one or more of the examples described.

[0139] As another example, the apparatus 1210 may be a network node, e.g., the network node described previously. In another example, the apparatus may be comprised in such a network node, e.g., as a chipset configured to control the network node. The apparatus 1210 may be caused or configured to perform at least the method of any one or more of the examples described.

[0140] The apparatus may comprise one or more entities of any of protocol layers, such as a MAC entity, an RRC entity, an RLC entity, a PDCP entity or a PHY entity. In some examples, the entity may be configured to perform at least the method of and / or any one or more of the examples described.

[0141] The apparatus 1210 may comprise a radio interface 1216. The radio interface 1216 may provide the apparatus 1210 with communication capabilities. The radio interface 1216 may comprise a receiver configured to receive information in accordance with at least one cellular or non-cellular standard. The radio interface 1216 may comprise a transmitter configured to transmit information in accordance with at least one cellular or non-cellular standard. The receiver may comprise more than one receiver. The transmitter may comprise more than one transmitter. The radio interface 1216 may comprise a transceiver configured to receive and transmit information in accordance with at least one cellular or non-cellular standard. The transceiver may comprise more than one transceiver.

[0142] The apparatus 1210 may comprise a user interface 1128 comprising, for example, at least one of a keypad, a microphone, a touch display, a display, a speaker, etc. The user interface 1218 may be used to control the apparatus by the user. The user interface 1218 may be external to the apparatus 1210. For example, the apparatus 1210 may be connected to another device, such as a computer, either via wireless or wired connection, and the apparatus 1210 is controlled by the user via the computer.

[0143] In some examples, at least some of the processes described herein may be carried out by an apparatus comprising means for carrying out at least some of the described processes. Means for performing method steps as disclosed herein may include software and / or hardware components of the apparatus 1210. For example, the at least one processor 1212, the memory 1214, and the computer program code form means for carrying out the method or methods as disclosed herein, and any of the examples. As used herein the term “means” is to be construed in singular form, i.e. referring to a single element, or in plural form, i.e. referring to a combination of single elements. Therefore, terminology “means for [performing A, B, C]”, is to be interpreted to cover an apparatus in which there is only one means for performing A, B and C, or where there are separate means for performing A, B and C, or partially or fully overlapping means for performing A, B, C. Further, terminology “means for performing A, means for performing B, means for performing C” is to be interpreted to cover an apparatus in which there is only one means for performing A, B and C, or where there are separate means for performing A, B and C, or partially or fully overlapping means for performing A, B, C.

[0144] The scope of protection sought for various examples of the disclosure is set out by the independent claims. The examples and features thereof, if any, described in this disclosure that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various examples of this disclosure.

[0145] Even though examples of this disclosure have been described above with reference to the accompanying drawings, it is clear that the examples are not restricted thereto but can be modified in several ways within the scope of this disclosure. Therefore, all words and expressions should be interpreted broadly, and they are intended to illustrate, not to restrict, the examples. It is understood, as technology advances, the scope of this disclosure can be implemented and adapted in various ways. Further, it is clear to a person skilled in the art that the described examples may, but are not required to, be combined with other examples in various manners.

Claims

1. A user equipment comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the user equipment at least to perform:storing information of a list of cells, the list of cells comprising a primary cell and one or more secondary cells, and associating at least one combination of cells from the list of cells with a carrier switching pattern;indicating capabilities of the user equipment to operate with a first carrier aggregation combination and a second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern;using the first carrier aggregation combination and in response to an instruction received at the user equipment to connect to the at least one combination of cells that is associated with the carrier switching pattern, transitioning the user equipment from using the first carrier aggregation combination to using the second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern and the carrier switching pattern causes the user equipment to switch between a first carrier and a second carrier.

2. A user equipment according to claim 1, the user equipment further caused to store an implementation, and to use the implementation to determine when to check for the switching pattern and to check the identity of the carriers to which the switching pattern is to be applied.

3. A user equipment according to claim 2, wherein the check of the identity of the carriers to which the switching pattern is to be applied includes checking that those carriers include at least one supplementary downlink carrier.

4. A user equipment according to claim 3, wherein the supplementary downlink carrier comprises a frequency division duplexing carrier.

5. A user equipment according to any preceding claim, wherein the user equipment is further caused to react to activation and / or de-activation of the primary cell and / or one or more secondary cells, and to selectively activate and de-activate the switching pattern accordingly.

6. A user equipment according to claim 5, wherein the user equipment is further caused to obtain, from one or more media access control messages received at the user equipment, information of the activation and / or de-activation of the primary cell and one or more secondary cells.

7. A user equipment according to claim 5 or claim 6, the user equipment further caused to activate the switching pattern based on the activation and / or de-activation of the one or more secondary cells.

8. A user equipment according to any of claims 1 to 7, the user equipment further caused to monitor an impact of the switching pattern on the one or more secondary cells.

9. A user equipment according to claim 8, wherein the monitoring an impact of the switching pattern comprises performing cell measurements on the one or more secondary cells.

10. A user equipment according to any preceding claim, wherein the first and second carriers of the second carrier aggregation combination comprise low-band carriers.

11. A user equipment according to any preceding claim, wherein the second carrier of the second carrier aggregation combination comprises a supplementary downlink carrier.

12. A user equipment according to any preceding claim, wherein the first carrier aggregation combination comprises at least one carrier that is not a low-band carrier.

13. A user equipment according to any preceding claim, wherein when using the first carrier aggregation combination the user equipment utilises one or more carriers that operate in a continuous fashion without switching.

14. A user equipment according to any of claims 1 to 13, wherein in the second carrier aggregation combination at least one further carrier remains available in a continuous manner, in addition to the first and second carriers.

15. A user equipment according to any preceding claim, wherein the transitioning the user equipment from the first carrier aggregation combination to the second carrier aggregation combination occurs whilst the apparatus remains connected to the primary cell and is moving towards a cell edge of the primary cell.

16. A user equipment according to any preceding claim, wherein the transitioning the apparatus from the first carrier aggregation combination to the second carrier aggregation combination occurs in response to the user equipment moving, in relation to the primary cell, from a near field region to a far field region via a transition field region, and the user equipment is caused to activate the second carrier aggregation combination when moving from the transition field region to the far field region.

17. A user equipment according to claim 16, wherein when moving back from the far field region to the transition field region the user equipment is configured with the first carrier aggregation combination.

18. A method performed by a user equipment, the method comprising:storing information of a list of cells, the list of cells comprising a primary cell and one or more secondary cells, and associating at least one combination of cells from the list of cells with a carrier switching pattern;indicating capabilities of the user equipment to operate with a first carrier aggregation combination and a second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern;using the first carrier aggregation combination and in response to an instruction received at the user equipment to connect to the at least one combination of cells that is associated with the carrier switching pattern, transitioning the apparatus from using the first carrier aggregation combination to using the second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern and the carrier switching pattern causes the user equipment to switch between a first carrier and a second carrier.

19. A method according to claim 18, the method comprising storing an implementation, and using the implementation to determine when to check for the switching pattern and to check the identity of the carriers to which the switching pattern is to be applied.

20. A method according to claim 19, wherein the check of the identity of the carriers to which the switching pattern is to be applied includes checking that those carriers include at least one supplementary downlink carrier.

21. A method according to claim 20, wherein the supplementary downlink carrier comprises a frequency division duplexing carrier.

22. A method according to any of claims 18 to 21, comprising reacting to activation and / or de-activation of the primary cell and / or one or more secondary cells, and selectively activating and de-activating the switching pattern accordingly.

23. A method according to claim 22, comprising obtaining, from one or more media access control messages received at the user equipment, information of the activation and / or de-activation of the primary cell and one or more secondary cells.

24. A method according to claim 22 or claim 23, the method comprising activating the switching pattern based on the activation and / or de-activation of the one or more secondary cells.

25. A computer program comprising instructions which, when executed by a user equipment, cause the user equipment to perform at least the following:storing information of a list of cells, the list of cells comprising a primary cell and one or more secondary cells, and associating at least one combination of cells from the list of cells with a carrier switching pattern;indicating capabilities of the user equipment to operate with a first carrier aggregation combination and a second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern;using the first carrier aggregation combination and in response to an instruction received at the user equipment to connect to the at least one combination of cells that is associated with the carrier switching pattern, transitioning the user equipment from using the first carrier aggregation combination to using the second carrier aggregation combination, wherein the second carrier aggregation combination utilises the carrier switching pattern and the carrier switching pattern causes the user equipment to switch between a first carrier and a second carrier.

Images