Patent Description:
The present application claims the Paris convention priority of <CIT>.

Future wireless communications networks will be expected to routinely and efficiently support communications with a wider range of devices associated with a wider range of data traffic profiles and types than current systems are optimised to support. For example it is expected future wireless communications networks will be expected to efficiently support communications with devices including reduced complexity devices, machine type communication (MTC) devices, high resolution video displays, virtual reality headsets and so on. Some of these different types of devices may be deployed in very large numbers, for example low complexity devices for supporting the "The Internet of Things", and may typically be associated with the transmissions of relatively small amounts of data with relatively high latency tolerance.

Another example of such a new service is referred to as Ultra Reliable Low Latency Communications (URLLC) services which, as its name suggests, requires that a data unit or packet be communicated with a high reliability and with a low communications delay. URLLC type services therefore represent a challenging example for both LTE type communications systems and <NUM>/NR communications systems.

The increasing use of different types of terminal devices associated with different traffic profiles gives rise to new challenges for efficiently handling communications in wireless telecommunications systems that need to be addressed.

In the document <NPL>, there is disclosed considerations for a wireless access interface using multiple bandwidth parts.

Various aspects and features of the present invention are defined in the appended claims. Embodiments of the present technique can provide a communications device for communicating in a wireless communications network, the communications device comprising a transceiver configured to transmit signals and to receive signals on a wireless access interface of the wireless communications network using a plurality of currently activated bandwidth parts, each of the plurality of currently activated bandwidth parts being formed from communications resources of a carrier within a carrier bandwidth, and a processor configured to control the transceiver to transmit the signals and to receive the signals. The processor is configured in combination with the transceiver to transmit signals or to receive signals using a first of the plurality of currently activated bandwidth parts, to receive, via the first of the plurality of currently activated bandwidth parts, an indication of one or more other bandwidth parts to be activated, to select one or more of the plurality of currently activated bandwidth parts to be de-activated in accordance with a maximum number of activated bandwidth parts permitted for the communications device, and in response to the selecting, to de-activate the selected one or more of the plurality of currently activated bandwidth parts.

Embodiments of the present technique, which further relate to infrastructure equipment, methods of operating communications devices and infrastructure equipment and circuitry for communications devices and infrastructure equipment, allow for the efficient use of communications resources in a wireless communications network.

Respective further aspects and features of the present disclosure are defined in the appended claims.

The network <NUM> includes a plurality of base stations <NUM> connected to a core network part <NUM>. Each base station provides a coverage area <NUM> (e.g. a cell) within which data can be communicated to and from terminal devices <NUM>. Data is transmitted from the base stations <NUM> to the terminal devices <NUM> within their respective coverage areas <NUM> via a radio downlink. Data is transmitted from the terminal devices <NUM> to the base stations <NUM> via a radio uplink. The core network part <NUM> routes data to and from the terminal devices <NUM> via the respective base stations <NUM> and provides functions such as authentication, mobility management, charging and so on. Terminal devices may also be referred to as mobile stations, user equipment (UE), user terminals, mobile radios, communications devices, and so forth. Base stations, which are an example of network infrastructure equipment / network access nodes, may also be referred to as transceiver stations / nodeBs / e-nodeBs, g-nodeBs and so forth. In this regard different terminology is often associated with different generations of wireless telecommunications systems for elements providing broadly comparable functionality. However, example embodiments of the disclosure may be equally implemented in different generations of wireless telecommunications systems, and for simplicity certain terminology may be used regardless of the underlying network architecture. That is to say, the use of a specific term in relation to certain example implementations is not intended to indicate these implementations are limited to a certain generation of network that may be most associated with that particular terminology.

<FIG> is a schematic diagram illustrating a network architecture for a new RAT wireless communications network / system <NUM> based on previously proposed approaches which may also be adapted to provide functionality in accordance with embodiments of the disclosure described herein. The new RAT network <NUM> represented in <FIG> comprises a first communication cell <NUM> and a second communication cell <NUM>. Each communication cell <NUM>, <NUM>, comprises a controlling node (centralised unit) <NUM>, <NUM> in communication with a core network component <NUM> over a respective wired or wireless link <NUM>, <NUM>. The respective controlling nodes <NUM>, <NUM> are also each in communication with a plurality of distributed units (radio access nodes / remote transmission and reception points (TRPs)) <NUM>, <NUM> in their respective cells. Again, these communications may be over respective wired or wireless links. The distributed units <NUM>, <NUM> are responsible for providing the radio access interface for terminal devices connected to the network. Each distributed unit <NUM>, <NUM> has a coverage area (radio access footprint) <NUM>, <NUM> which together define the coverage of the respective communication cells <NUM>, <NUM>. Each distributed unit <NUM>, <NUM> includes transceiver circuitry for transmission and reception of wireless signals and processor circuitry configured to control the respective distributed units <NUM>, <NUM>.

Depending on the application at hand the responsibility for scheduling transmissions which are scheduled on the radio interface between the respective distributed units and the terminal devices may lie with the controlling node / centralised unit and / or the distributed units / TRPs.

A terminal device <NUM> is represented in <FIG> within the coverage area of the first communication cell <NUM>. This terminal device <NUM> may thus exchange signalling with the first controlling node <NUM> in the first communication cell via one of the distributed units <NUM> associated with the first communication cell <NUM>. In some cases communications for a given terminal device are routed through only one of the distributed units, but it will be appreciated in some other implementations communications associated with a given terminal device may be routed through more than one distributed unit, for example in a soft handover scenario and other scenarios.

The particular distributed unit(s) through which a terminal device is currently connected through to the associated controlling node may be referred to as active distributed units for the terminal device. Thus the active subset of distributed units for a terminal device may comprise one or more than one distributed unit (TRP). The controlling node <NUM> is responsible for determining which of the distributed units <NUM> spanning the first communication cell <NUM> is responsible for radio communications with the terminal device <NUM> at any given time (i.e. which of the distributed units are currently active distributed units for the terminal device). Typically this will be based on measurements of radio channel conditions between the terminal device <NUM> and respective ones of the distributed units <NUM>. In this regard, it will be appreciated that the subset of the distributed units in a cell which are currently active for a terminal device will depend, at least in part, on the location of the terminal device within the cell (since this contributes significantly to the radio channel conditions that exist between the terminal device and respective ones of the distributed units).

In at least some implementations the involvement of the distributed units in routing communications from the terminal device to a controlling node (controlling unit) is transparent to the terminal device <NUM>. That is to say, in some cases the terminal device may not be aware of which distributed unit is responsible for routing communications between the terminal device <NUM> and the controlling node <NUM> of the communication cell <NUM> in which the terminal device is currently operating, or even if any distributed units <NUM> are connected to the controlling node <NUM> and involved in the routing of communications at all. In such cases, as far as the terminal device is concerned, it simply transmits uplink data to the controlling node <NUM> and receives downlink data from the controlling node <NUM> and the terminal device has no awareness of the involvement of the distributed units <NUM>, though may be aware of radio configurations transmitted by distributed units <NUM>. However, in other embodiments, a terminal device may be aware of which distributed unit(s) are involved in its communications. Switching and scheduling of the one or more distributed units may be done at the network controlling node based on measurements by the distributed units of the terminal device uplink signal or measurements taken by the terminal device and reported to the controlling node via one or more distributed units.

In the example of <FIG>, two communication cells <NUM>, <NUM> and one terminal device <NUM> are shown for simplicity, but it will of course be appreciated that in practice the system may comprise a larger number of communication cells (each supported by a respective controlling node and plurality of distributed units) serving a larger number of terminal devices.

Thus example embodiments of the disclosure as discussed herein may be implemented in wireless telecommunication systems / networks according to various different architectures, such as the example architectures shown in <FIG> and <FIG>. It will thus be appreciated the specific wireless communications architecture in any given implementation is not of primary significance to the principles described herein. In this regard, example embodiments of the disclosure may be described generally in the context of communications between network infrastructure equipment / access nodes and a terminal device, wherein the specific nature of the network infrastructure equipment / access node and the terminal device will depend on the network infrastructure for the implementation at hand. For example, in some scenarios the network infrastructure equipment / access node may comprise a base station, such as an LTE-type base station <NUM> as shown in <FIG> which is adapted to provide functionality in accordance with the principles described herein, and in other examples the network infrastructure equipment / access node may comprise a control unit / controlling node <NUM>, <NUM> and / or a TRP <NUM>, <NUM> of the kind shown in <FIG> which is adapted to provide functionality in accordance with the principles described herein.

In wireless telecommunications networks, such as LTE type or <NUM> type networks, there are different Radio Resource Control (RRC) modes for terminal devices. For example, it is common to support an RRC idle mode (RRC_IDLE) and an RRC connected mode (RRC_CONNECTED). A terminal device in the idle mode may transition to the RRC connected mode, for example because it needs to transmit uplink data or respond to a paging request, by undertaking a random access procedure. The random access procedure involves the terminal device transmitting a preamble on a physical random access channel and so the procedure is commonly referred to as a RACH or PRACH procedure / process.

Thus a conventional way for a terminal device (UE) in the RRC idle mode to exchange data with a network involves the terminal device first performing an RRC connection procedure (random access procedure) with the network.

After establishing an RRC connection and exchanging the relevant data, the UE may then perform RRC disconnection and move back into idle mode for power saving.

A wireless telecommunications network, such as a <NUM> (NR) network may support an RRC Inactive (RRC_INACTIVE) mode, in which, as in the RRC idle mode, it may not transmit data, but must transition to the RRC connected mode in order to transmit or receive data. In both the RRC Inactive and RRC Idle modes, mobility (i.e. change of serving cell) is by means of UE-based cell reselection in accordance with parameters transmitted by the wireless telecommunications network. In the RRC connected mode, mobility may be network-controlled; that is, a handover may be initiated by an infrastructure equipment of the network. The handover may be conventionally initiated in response to, for example, measurement reports transmitted by the terminal device, which may indicate the result of measurements of downlink signals transmitted by the network in both the serving cell and one or more neighbour (candidate) cells.

As mentioned above, the embodiments of the present invention can also find application with advanced wireless communications systems such as those referred to as <NUM> or New Radio (NR) Access Technology. The use cases that are considered for NR include:.

eMBB services are characterised by high capacity with a requirement to support up to <NUM> Gb/s. The requirement for URLLC is a reliability of <NUM> - <NUM>-<NUM> (<NUM> %) for one transmission of a <NUM> byte packet with a user plane latency of <NUM> [<NUM>].

The elements of the wireless access network shown in <FIG> may be equally applied to a <NUM> new RAT configuration, except that a change in terminology may be applied as mentioned above.

Ultra reliable low latency communications (URLLC) service, have recently been proposed within 3GPP for <NUM> and <NUM> communications networks. In some examples, URLLC communications are either low latency (where the user plane latency target is <NUM>) or high reliability (where the acceptable error rate on URLLC transmissions is <NUM>-<NUM>) or both low latency and high reliability (where both the latency and reliability targets need to be met at the same time).

Various techniques have been proposed in order to achieve the low latency and high reliability targets. Low latency can be achieved through one or more of the following techniques (which can be applied in combination):.

The short TTI referred to above can be termed a "mini-slot". The scheduling interval may also have an extent of a mini-slot.

High reliability can be achieved through one or more of the following techniques (which can be applied in combination):.

A communications device and an infrastructure equipment, such as the communications device <NUM> and infrastructure equipment <NUM> of <FIG>, are configured to communicate via a wireless access interface. The wireless access interface may comprise one or more carriers, each providing within a ranges of carrier frequencies communications resources for transmitting and receiving signals according to a configuration of the wireless access interface. The one or more carriers may be configured within a system bandwidth provided for the wireless communications network of which the infrastructure equipment <NUM> forms part. Each of the carriers may be divided in a frequency division duplex scheme into an uplink portion and a downlink portion and may comprise one or more bandwidth parts (BWPs). A carrier may be configured therefore with a plurality of different BWP for a communications device to transmit or receive signals.

The nature of the wireless access interface may be different amongst the different BWPs. For example, where the wireless access interface is based on orthogonal frequency division multiplexing, different BWPs may have different sub-carrier spacing, symbol periods and/or cyclic prefix lengths.

By configuring BWPs appropriately, the infrastructure equipment may provide BWPs which are suited for different types of services. For example, a BWP more suitable for eMBB may have a larger bandwidth in order to support high data rates. A BWP suited for URLLC services may use a higher sub-carrier spacing and shorter slot durations, in order to permit lower latency transmissions.

Parameters of the wireless access interface which are applicable to a BWP (e.g. sub-carrier spacing, symbol and slot durations, cyclic prefix lengths) may be referred to collectively as the numerology of a BWP.

<FIG> shows an example of first to fourth BWPs 401a-d configured within a system bandwidth <NUM>. The following Table <NUM> provides a summary of characteristics (including the 'numerology') of each of the BWPs 401a-d:.

As shown in Table <NUM>, each BWP may be identified by an index number.

In the example in <FIG>, the BWPs 401a-d are non-overlapping and collectively span the entire system bandwidth <NUM>. However, in some examples, the frequency range of one or more BWPs may overlap, or be entirely within, the frequency range of another BWP. Furthermore, it is not necessary that all frequencies within the system bandwidth <NUM> are within the range of one or more BWPs.

Prior to being activated, a BWP may be configured for use by the communications device <NUM>. That is, the communications device <NUM> may determine the characteristics of the BWP, for example, by means of radio resource control (RRC) signalling transmitted by the infrastructure equipment <NUM>.

In some configurations (for example, in unpaired spectrum), uplink and downlink BWPs may be paired, such that any reference herein to a BWP may refer to a pair of BWPs, the pair comprising one uplink BWP and one downlink BWP. Accordingly, for example, 'activation' and 'de-activation' of a BWP may refer to the simultaneous activation or de-activation of a pair of BWPs.

Alternatively, in some embodiments, bi-directional communications may be possible within a single BWP.

In other configurations (for example, in paired spectrum) uplink and downlink BWPs may be configured and activated independently of all other BWPs [<NUM>]. References to 'a number' of BWPs (including a maximum number of BWPs) may therefore, in some configurations, refer only to downlink BWPs or only to uplink BWPs.

Conventionally, at most one BWP per direction may be activated at any given time in respect of a particular communications device.

Through the use of BWPs, a communications device may reduce its power consumption by operating only using the range of carrier frequencies which are within the activated BWP(s), which may be considerably smaller than the bandwidth of the carrier in which the BWPs are formed. For power-constrained devices (such as those that are battery-powered, and particularly for those, such as machine type communications devices, which may not be easily re-charged), such a reduction in power consumption may be of particular benefit.

An activated BWP refers to a BWP which, for the communications device <NUM>, may be used for the transmission or reception of data to or from the communications device <NUM>. As such, an infrastructure equipment may schedule transmissions to or by the communications device <NUM> only on a BWP if that BWP is currently activated for the communications device <NUM>.

On deactivated downlink BWPs, the communications device <NUM> may not monitor the PDCCH, and on deactivated uplink BWPs, the communications device <NUM> does not transmit on PUCCH, PRACH and UL-SCH. In general terms, an activated BWP may be used for the transmission of data to (on a downlink BWP) or by (on an uplink BWP) the communications device <NUM>.

The communications device <NUM> may maintain a deactivation timer in respect of each activated BWP. The deactivation timer may be started when data is transmitted or received using the BWP. If a deactivation timer expires, the associated BWP may be deactivated.

However, in light of the differing numerologies which may be applicable to BWPs, a single activated BWP may not be suitable for the transmission of data associated with different services, if those different services have different requirements (e.g. latency requirements) or characteristics (e.g. bandwidth / data rate). Additionally or alternatively, there may be insufficient capacity on a single BWP for the requirements of a single communications device Therefore, consideration has been given to the possibility of activating multiple BWPs for a single communications device.

However, a communications device may be limited in terms of the maximum number of BWPs which may be simultaneously activated.

However, no mechanism currently exists to control the activation and/or deactivation of BWPs in a scenario where a communications device <NUM> supports two or more activated BWPs in the same direction (i.e. uplink or downlink) simultaneously, and in particular where the communications device <NUM> supports at most a predetermined number (maximum) of activated BWPs per direction simultaneously.

According to embodiments of the present disclosure, there is provided a communications device for communicating with an infrastructure equipment of a wireless communications network, the communications device comprising a transceiver configured to transmit signals and to receive signals on a wireless access interface of the wireless communications network using a plurality of activated bandwidth parts, each of the bandwidth parts being formed from communications resources of a carrier within a carrier bandwidth, and a processor configured to control the transceiver to transmit the signals and to receive the signals. The processor is configured in combination with the transceiver to transmit signals or to receive signals using a first of the plurality of activated bandwidth parts, to receive, via the first activated bandwidth part, an indication of one or more bandwidth parts to be activated, to select one or more bandwidth parts to be de-activated in accordance with a maximum number of activated bandwidth parts permitted for the communications device, and in response to the selecting, to de-activate the selected one or more bandwidth parts.

A BWP may be designated as a primary BWP which is always activated and which may be used for transmitting control information to or by the communications device <NUM> (depending on whether it is an uplink or downlink BWP). Since the primary BWP is always activated (and thus may be used for data transmission), it may be necessary to activate one or more further (secondary) BWPs only if the primary BWP is unsuitable (e.g. because of its numerology) or insufficient e.g. due to congestion or lack of bandwidth.

Because the primary BWP is always activated, the communications device <NUM> may not maintain a deactivation timer associated with the primary BWP.

Alternatively, a BWP may be designated as a default type BWP, that is, a BWP having an activation or deactivation priority which differs from the activation or deactivation priority of other, non-default BWPs. In some embodiments, as will be described, a default BWP may be preferentially activated or deactivated with lowest preference. A default type BWP (which may be referred to as a default BWP) may further be preferentially used for transmitting an indication that a different BWP is to be activated or de-activated. There may be one or more default BWPs.

<FIG> schematically shows a telecommunications system <NUM> according to an embodiment of the present disclosure. The telecommunications system <NUM> in this example is based broadly around an LTE-type architecture. As such many aspects of the operation of the telecommunications system / network <NUM> are known and understood and are not described here in detail in the interest of brevity. Operational aspects of the telecommunications system <NUM> which are not specifically described herein may be implemented in accordance with any known techniques, for example according to the current LTE-standards.

The telecommunications system <NUM> comprises a core network part (evolved packet core) <NUM> coupled to a radio network part. The radio network part comprises a base station (evolved-nodeB) <NUM> coupled to a plurality of terminal devices. In this example, two terminal devices are shown, namely a first terminal device <NUM> and a second terminal device <NUM>. It will of course be appreciated that in practice the radio network part may comprise a plurality of base stations serving a larger number of terminal devices across various communication cells. However, only a single base station and two terminal devices are shown in <FIG> in the interests of simplicity.

As with a conventional mobile radio network, the terminal devices <NUM>, <NUM> are arranged to communicate data to and from the base station (transceiver station) <NUM>. The base station is in turn communicatively connected to a serving gateway, S-GW, (not shown) in the core network part which is arranged to perform routing and management of mobile communications services to the terminal devices in the telecommunications system <NUM> via the base station <NUM>. In order to maintain mobility management and connectivity, the core network part <NUM> also includes a mobility management entity (not shown) which manages the enhanced packet service (EPS) connections with the terminal devices <NUM>, <NUM> operating in the communications system based on subscriber information stored in a home subscriber server (HSS). Other network components in the core network (also not shown for simplicity) include a policy charging and resource function (PCRF) and a packet data network gateway (PDN-GW) which provides a connection from the core network part <NUM> to an external packet data network, for example the Internet. As noted above, the operation of the various elements of the communications system <NUM> shown in <FIG> may be broadly conventional apart from where modified to provide functionality in accordance with embodiments of the present disclosure as discussed herein.

The terminal devices <NUM>, <NUM> (which may correspond to the terminal device <NUM>) comprise transceiver circuitry 506a, 508a (which may also be referred to as a transceiver / transceiver unit) for transmission and reception of wireless signals and processor circuitry 506b, 508b (which may also be referred to as a processor / processor unit) configured to control the devices <NUM>, <NUM>. The processor circuitry 506b, 508b may comprise various sub-units / sub-circuits for providing functionality as explained further herein. These sub-units may be implemented as discrete hardware elements or as appropriately configured functions of the processor circuitry. Thus the processor circuitry 506b, 508b may comprise circuitry which is suitably configured / programmed to provide the desired functionality using conventional programming / configuration techniques for equipment in wireless telecommunications systems. The transceiver circuitry 506a, 508a and the processor circuitry 506b, 508b are schematically shown in <FIG> as separate elements for ease of representation. However, it will be appreciated that the functionality of these circuitry elements can be provided in various different ways, for example using one or more suitably programmed programmable computer(s), or one or more suitably configured application-specific integrated circuit(s) / circuitry / chip(s) / chipset(s). As will be appreciated the terminal devices <NUM>, <NUM> will in general comprise various other elements associated with its operating functionality, for example a power source, user interface, and so forth, but these are not shown in <FIG> in the interests of simplicity.

The base station <NUM> (which may correspond to the infrastructure equipment <NUM>) comprises transceiver circuitry 504a (which may also be referred to as a transceiver / transceiver unit) for transmission and reception of wireless signals and processor circuitry 504b (which may also be referred to as a processor / processor unit) configured to control the base station <NUM> to operate in accordance with embodiments of the present disclosure as described herein. The processor circuitry 504b may comprise various sub-units / sub-circuits for providing desired functionality as explained further herein. These sub-units may be implemented as discrete hardware elements or as appropriately configured functions of the processor circuitry. Thus the processor circuitry 504b may comprise circuitry which is suitably configured / programmed to provide the desired functionality described herein using conventional programming / configuration techniques for equipment in wireless telecommunications systems. The transceiver circuitry 504a and the processor circuitry 504b are schematically shown in <FIG> as separate elements for ease of representation. However, it will be appreciated that the functionality of these circuitry elements can be provided in various different ways, for example using one or more suitably programmed programmable computer(s), or one or more suitably configured application-specific integrated circuit(s) / circuitry / chip(s) / chipset(s). It will be appreciated the base station <NUM> will in general comprise various other elements associated with its operating functionality.

Thus, the base station <NUM> is configured to communicate data with the terminal devices <NUM>, <NUM> according to an embodiment of the disclosure over respective communication links <NUM>, <NUM>. The base station <NUM> is configured to communicate with the terminal device <NUM> over the associated radio communication link <NUM> and with the terminal device <NUM> over the associated radio communication link <NUM> generally following the established principles of LTE-based of <NUM>/NR communications, apart from using modified procedures in accordance with certain embodiments of the present disclosure as described herein.

According to an embodiment of the present technique, a first BWP (such as the first BWP 401a of <FIG>) may be deactivated by the communications device <NUM> in response to receiving an indication transmitted by the infrastructure equipment that one or more different BWPs (such as the second and third BWPs 401b,c of <FIG>) are to be activated. The BWP 401a to be deactivated may preferably be the BWP on which the indication was received.

This approach has the benefit of requiring very limited signalling in order to send the indication, since only the identity of the activated BWP(s) needs to be transmitted.

According to the embodiment, the communications device <NUM> receives an indication from the infrastructure equipment <NUM> that one or more BWPs 401b,c are to be activated, the indication preferably received on a currently activated BWP 401a. In response to the receiving, the infrastructure equipment <NUM> activates the BWPs 401b,c to be activated and deactivates the BWP 401a on which the indication was received.

Accordingly, the infrastructure equipment <NUM>, having transmitted to the communications device <NUM> the indication, determines that the communications device <NUM> has deactivated the BWP 401a on which the indication was transmitted. As such, the infrastructure equipment <NUM> no longer is able to schedule transmissions on the now deactivated BWP 401a.

According to a further embodiment, an explicit indication, allowing the communications device <NUM> to identify one or more BWPs to be deactivated (for example, the second BWP 401b of <FIG>), is transmitted to the communications device <NUM> by the infrastructure equipment <NUM>. The indication may be communicated in downlink control information (DCI). In order to indicate to the communications device <NUM> that the DCI contains an indication of which BWP(s) is/are to be deactivated, the DCI may be formatted in a pre-determined manner. For example, a pre-determined radio network temporary identifier (RNTI) may be used to construct the DCI for transmission. The communications device <NUM> may, having received the DCI and having detected the pre-determined RNTI, thus determine that the DCI contains an indication of one or more BWPs to be deactivated.

In some embodiments, the DCI, when formatted to include an indication of one or more BWPs to be deactivated, does not contain any indication of scheduled transmissions on a shared channel (such as a PDSCH or PUSCH).

In some embodiments, the DCI may be group-common DCI, containing information for multiple communications device <NUM>. In order to differentiate group-common DCI used to indicate BWPs to be deactivated from other group-common DCI, a pre-determined RNTI may be used in the transmission of the group-common DCI used to indicate BWPs to be deactivated, different from RNTI(s) used for other group-common DCI.

Accordingly, the infrastructure equipment <NUM> may form DCI comprising an indication identifying one or more BWPs 401b to be deactivated. The DCI may be formatted in a predetermined manner (e.g. DCI format) and/or may be formed with (e.g. some portion may be scrambled with) a pre-determined RNTI, to indicate that it contains an indication of BWPs to be deactivated.

In some embodiments of the present technique, one or more BWPs may be activated by the communications device <NUM> in response to receiving DLDCI or UL DCI on the primary BWP. Because the primary BWP may be always activated, this provides a method of activating one or more BWPs which is always available.

Alternatively, in some embodiments, DCI transmitted on a default BWP may indicate one or more BWPs to be activated. Preferably, the communications device <NUM> may determine whether the total number of BWPs activated by means of DCI transmitted on the default BWP exceeds a predetermined number. In response to determining that the total number of BWPs activated by means of the DCI exceeds the predetermined number then the communications device <NUM> deactivates the default BWP. The predetermined number may be less than the maximum number of activated BWPs which the communications device <NUM> supports.

In some embodiments, the default BWP may have a relatively low capacity. For example, the bandwidth of the default BWP may span a low frequency range, relative to other configured BWPs. In some embodiments, for example, the default BWP may be defined as the configured BWP having the smallest bandwidth of all configured BWPs. As such, keeping the default BWP activated while other BWPs are activated may provide a limited additional bandwidth or capacity, while resulting in additional power consumption by the communications device. The other BWPs may have higher capacity or be more suited to the current data transmission or reception requirements of the communications device <NUM>.

The predetermined number may be preferably known to the infrastructure equipment <NUM>. Accordingly, the infrastructure equipment <NUM> may determine that one or more BWPs are to be activated for the communications device <NUM>, and consequently transmits DCI on the default BWP indicating the BWP(s) to be activated. The infrastructure equipment <NUM> may determine whether the total number of BWPs activated by means of the DCI exceeds the predetermined number. In response to determining that the total number of BWPs activated by means of the DCI exceeds the predetermined number then the infrastructure equipment <NUM> may determine that the communications device <NUM> has deactivated the default BWP and the infrastructure equipment <NUM> therefore refrains from scheduling transmissions on the default BWP.

In some embodiments the default BWP may be used by the infrastructure equipment <NUM> to transmit DCI indicating that one or more other BWPs are to be activated. In such embodiments, the default BWP may remain activated unless the total number of activated BWPs would exceed the maximum number of activated BWPs which the communications device <NUM> supports.

In some such embodiments, the default BWP, if not already activated, may be activated automatically whenever an activated BWP (which is not the default BWP) becomes deactivated, for example, as the result of an associated inactivity timer expiring on the activated BWP. This has the effect of ensuring that the default BWP is activated as much as possible, within the constraints of the maximum number of activated BWPs which the communications device <NUM> supports. As such, the default BWP may be said to have an activation priority which is higher than the activation priority of other (non-default) BWPs which are configured.

If the default BWP is not active (for example, because this would require the number of activated BWPs to exceed the maximum number of activated BWPs which the communications device <NUM> supports, or for any other reason) then in some embodiments, DCI transmitted by the infrastructure equipment <NUM> to the communications device <NUM> on one of the activated non-default BWPs may indicate one or more other (inactivated) BWPs which are to be activated, or may indicate that one or more activated BWPs are to be deactivated.

In some embodiments, the default BWP is activated if another BWP is deactivated and no other BWP remains activated. Similarly, if the default BWP is activated and another BWP is also activated, the default BWP is automatically deactivated. In such embodiments, the default BWP (if not explicitly activated otherwise) may be activated if, and only if, no other BWP is activated. As such, the default BWP may be said to have an activation priority which is lower than the activation priority of other (non-default) BWPs which are configured.

An example of an embodiment of the present technique is shown in <FIG>. In the example of <FIG>, the third BWP 401c is designated as the default BWP, and the maximum number of activated BWPs which the communications device <NUM> supports is three.

Prior to time t1, only the third BWP 401c (i.e. the default BWP) is activated. At time t1, the second and fourth BWPs (401b, 401d) are activated. The activation of the second and fourth BWPs may be in response to a demand for data transmission bandwidth, and may be indicated to the communications device <NUM> by the infrastructure equipment <NUM> transmitting DCI using the default BWP 401c.

Subsequently, at time t2, the first BWP 401a is also activated by the communications device <NUM>. The first BWP 401a may be activated for example, as a result of receiving DCI on the third BWP 401c indicating that the first BWP 401a is to be activated. Because the activation of the first BWP 401a would result in the number of activated BWPs (four) exceeding the maximum number of activated BWPs which the communications device <NUM> supports (three), then in accordance with some embodiments of the present technique, the default (third) BWP 401c is deactivated.

<FIG> illustrates an embodiment of the present technique in which the communications device <NUM> activates a default BWP in response to the expiry of an inactivity timer associated with a non-default BWP.

In the example of <FIG>, as in <FIG>, the third BWP 401c is designated as the default BWP, and the maximum number of activated BWPs which the communications device <NUM> supports is three.

Prior to time t3, three non-default BWPs 401a, 401b and 401d are activated. At time t3, data is transmitted on the first BWP 401a and an inactivity timer is restarted. At time t4, there having been no further data transmission on the first BWP 401a, the inactivity timer expires and the first BWP 401a is deactivated; no other inactivity timer associated with another BWP expires prior to time t4. As a result of this deactivation, and because i) the default BWP is not active, and ii) activating the default BWP would not cause the number of activated BWPs to exceed the maximum number of activated BWPs which the communications device <NUM> supports, then the default BWP 401c is activated by the communications device <NUM>.

<FIG> illustrates further examples of BWP activation and deactivation, in accordance with embodiments of the present technique.

In the example of <FIG>, the second BWP 401b is designated as the default BWP.

Prior to time t1, only the default BWP 401b is activated. At time t1, a non-default BWP (in this case, the fourth BWP 401d) is activated. Since at least one non-default BWP is activated, the default BWP 401b is deactivated. In other words, the communications device <NUM> determines whether, as a result of a BWP activation, at least one non-default BWP is (or is to be) activated and, if so, determines whether the default BWP is currently active. If both conditions are met then, when the non-default BWP is activated, the default BWP is deactivated.

In these embodiments, it is possible to activate and deactivate a BWP by means of signalling (for example, DCI) transmitted on an activated, non-default BWP. In the example shown in <FIG>, at time t2, the third BWP 401c is activated by means of signalling on the fourth BWP 401d.

Subsequently, at time t3, the third BWP 401c is deactivated and, at time t4, the fourth BWP 401d is deactivated. The deactivation of the third and fourth BWPs may be in response to an expiry of an associated inactivity timer, or to explicit signalling, or for any other reason.

At time t4, the communications device <NUM> determines whether, as a result of the deactivation of the fourth BWP 401d, any non-default BWPs will remain activated. In response to determining that no non-default BWPs will remain activated, the communications device <NUM> activates the default BWP 401b.

<FIG> illustrates a flow chart for a process carried out by the communications device <NUM> in accordance with embodiments of the present technique.

The process starts at step <NUM>, at which the communications device <NUM> determines one or more BWPs. For example, this may be in response to receiving RRC signalling from the infrastructure equipment <NUM>, the RRC signalling comprising an indication of the one or more configured BWPs. the RRC signalling may comprise, for each configured BWP, an index, a frequency range, and the numerology.

The process continues at step <NUM>, in which the communications device <NUM> determines the maximum number of activated BWPs which the communications device <NUM> supports. This may be, for example, stored in a memory of the communications device <NUM>.

At step <NUM>, the communications device <NUM> determines the default BWP. This may be indicated in the RRC signalling described above in step <NUM>. Alternatively, the default BWP may be determined according to a pre-configured rule; for example, it may be the BWP having the highest (or lowest) index number. Alternatively, it may be the BWP having the smallest frequency range.

At step <NUM>, the communications device <NUM> determines whether the default BWP is in fact activated; that is to say, for example, whether or not the communications device <NUM> is required to monitor a control channel transmitted using, or associated with, the default BWP.

Based on the outcome of the determination, control then passes to step <NUM> (if the default BWP is activated) or step <NUM> (if the default BWP is not activated).

In both steps <NUM> and <NUM>, the communications device <NUM> determines whether one or more BWPs other than the default BWP is activated; that is to say, for example, whether or not the communications device <NUM> is required to monitor a control channel transmitted using, or associated with, a BWP other than the default BWP.

If, at step <NUM>, it is determined that one or more non-default BWPs are activated, then control passes to step <NUM>, in which the default BWP is deactivated. Control then passes to step <NUM>. If, at step <NUM>, it is determined that no non-default BWP is activated, then control passes to step <NUM>.

If, at step <NUM>, it is determined that no non-default BWP is activated, then control passes to step <NUM>, in which the default BWP is activated. Control then passes to step <NUM>. If, at step <NUM>, it is determined that one or more non-default BWPs are activated, then control passes to step <NUM>.

Steps <NUM> and <NUM> comprise a determination as to whether or not criteria are met for deactivating (step <NUM>) or activating (step <NUM>) one or more BWPs. Criteria for deactivating may be based on a deactivation timer expiry or explicit signalling, or a determination by the communications device <NUM> that one or more BWPs should be deactivated, or receipt of signalling indicating a deactivation from the infrastructure equipment <NUM>. The determination by the communications device that one or more of the BWPs should be deactivated may be based on criteria including a data queue amount or other internal assessment of data transmission requirements.

Criteria for activating may be based on an increase in an amount of data for transmission, the generation or receipt of traffic for transmission for which the currently activated BWP(s) is/are not suitable (e.g. because of their numerology) or a receipt of signalling indicating an activation from the infrastructure equipment <NUM>.

If no criteria for activating a BWP are met, and no criteria for deactivating a BWP are met, then steps <NUM> and <NUM> are repeated.

If, at step <NUM>, it is determined that criteria for deactivating a BWP are met, then control passes to step <NUM>. At step <NUM>, the one or more BWP for which criteria for deactivation are met are deactivated, and control passes to step <NUM>.

If, at step <NUM>, it is determined that criteria for activating a BWP are met, then control passes to step <NUM>. At step <NUM>, the one or more BWP for which criteria for activation are met are activated, and control passes to step <NUM>.

Thus, by means of the process illustrated in <FIG>, the communications device <NUM> activates and deactivates BWPs in response to pre-determined criteria, and activates and deactivates the default BWP based on the activation state of the other (non-default) BWPs.

Preferably, in some embodiments, when control passes to either steps <NUM> or <NUM> then, should control subsequently pass (as a result) to either steps <NUM> or <NUM>, the process should be controlled such that the one of the steps <NUM> and <NUM> occur substantially simultaneously with (or alternatively, after a delay of a pre-determined duration starting from) the one of steps <NUM> and <NUM>.

The example of <FIG> above may arise as the result of the process of <FIG>.

In some embodiments, therefore, the activation and deactivation of the default BWP may be determined based on one or more criteria (which may include, for example, the maximum number of activated BWPs which the communications device <NUM> can support, and the activation status of other, non-default, BWPs), thereby avoiding the need to explicitly signal to or by the infrastructure equipment <NUM> when the default BWP is to be activated or deactivated.

In some embodiments, an infrastructure equipment <NUM> may determine which (if any) BWPs are currently activated for a communications device <NUM> and which (if any) BWP is to be activated for the communications device <NUM>. Preferably, the algorithm or process (which may be in accordance with one or more embodiments described herein) according to which the communications device <NUM> activates or deactivates BWPs in response to determining that one or more BWPs are to be activated or deactivated is predetermined and known to the infrastructure equipment <NUM>; for example, the infrastructure equipment <NUM> may transmit an indication in system information or RRC signalling, received by the communications device <NUM>, the indication indicating what process is to be used by the communications device <NUM> in respect of BWP activation and deactivation. Alternatively, the process or algorithm may be standardised and documents in appropriate specifications.

In addition, where a primary BWP and/or default BWP is configured at the communications device <NUM>, the identity of these BWPs is known to the infrastructure equipment. This may be by means of predetermined (e.g. standardised) rules according to which the default and/or primary BWPs are selected from the configured BWPs, or by means of an explicit indication transmitted by either the communications device <NUM> or the infrastructure equipment <NUM> to the infrastructure equipment <NUM> or the communications device <NUM>, respectively.

The infrastructure equipment <NUM> may thus determine which, if any, BWPs will be deactivated or activated by the communications device <NUM>, and may schedule future transmissions accordingly. For example, it may refrain from transmitting control information (such as DCI) using a data channel (such as a PDCCH) on the deactivated BWP(s).

In some embodiments, the BWP designated in the examples above as the default BWP may be additionally or alternatively be designated as a primary BWP, and references to `default BWP' may, in such embodiments, refer to the primary BWP.

In some embodiments, the infrastructure equipment <NUM> may transmit an indication of one or more BWPs to be activated or deactivated. The indication of BWPs may be transmitted in a message on a shared channel (for example, the PDSCH). The communications device <NUM> may receive an indication of the resources of the shared channel used for the transmission of the activation / deactivation message on a control channel (for example, the PDCCH).

In some embodiments, DCI transmitted on a control channel may comprise an indication of the index of each BWP to be activated or deactivated. Where a BWP is to be activated, the DCI may further comprise an indication of the shared channel assignment associated with the BWP, which may comprise an assignment on a shared channel of communications resources within the frequency range of the BWP, for the transmission of data to or by the communications device <NUM>.

In some embodiments of the present technique, criteria for activating one or more BWPs may be met, however, the activation would result in the total number of activated BWPs exceeding the maximum number of BWPs which the communications device <NUM> can support.

Thus, in some embodiments of the present technique, when one or more BWPs are to be activated, the communications device <NUM> determines whether, as a result, the total number of activated BWPs would exceed the maximum number of BWPs which the communications device <NUM> can support.

If such a determination is made, then the communications device <NUM> may select one or more BWPs which are currently activated, to be deactivated in response, in accordance with a predetermined priority. The number of selected BWPs may preferably be the number required to be deactivated so that the sum of the number of remaining activated BWPs and the number of newly activated BWPs is equal to the maximum number of activated BWPs which can be supported by the communications device <NUM>. The selected BWP(s) may be selected from the currently activated BWPs, according to one or more of:.

In some embodiments, instead of selecting from only the BWPs which are currently activated, the communications device <NUM> may select from the set of BWPs consisting of the currently activated BWPs and those for which the criteria for activation have been met.

The predetermined priority may comprise one or more of the above selections, in a predetermined precedence order. For example, the default BWP may be selected with the highest priority; if it is necessary to select one or more further BWPs, these may be selected from those BWPs having a numerology (or aspect thereof) in common with one or more other.

The predetermined priority may comprise a 'tie-break' rule for selecting amongst multiple BWPs meeting a particular criteria, if it is not necessary to select all such BWPs. For example, the predetermined priority may be to select from BWPs having the lowest sub-carrier spacing, and where multiple such BWPs exist, those BWPs having the lowest index are selected.

The predetermined priority may be indicated by the infrastructure equipment <NUM> in signalling which is received by the communications device <NUM>. Additionally or alternatively, the priority may be specified in a specification for a standard to which the communications device <NUM> conforms. Preferably, the predetermined priority and the maximum number of activated BWPs which can be supported by the communications device <NUM> are known also to the infrastructure. Therefore, no additional indication needs to be transmitted to or by the infrastructure equipment <NUM> to indicate the selected BWP(s).

In some embodiments, therefore, an infrastructure equipment <NUM> may determine which (if any) BWPs are currently activated for the communications device <NUM>. The infrastructure equipment <NUM> may determine that a BWP, which is currently deactivated for the communications device <NUM> is to be activated for the communications device <NUM>. For example, the infrastructure equipment <NUM> may receive a request from the communications device <NUM> for communications resources to transmit traffic associated with a particular service, or a quality of service, for which the presently activated BWPs are not suitable or not sufficient (or both).

The infrastructure equipment <NUM> may subsequently transmit an indication to the communications device <NUM>, identifying one or more BWPs that are to be activated by the communications device <NUM>.

The infrastructure equipment <NUM> may further determine whether the sum of the number of currently activated BWPs for the communications device <NUM> and the number of BWPs that are to be activated exceeds the maximum number of activated BWPs which can be supported by the communications device <NUM>. If the sum would exceed the maximum number and criteria of activating a new BWP is met, then the infrastructure equipment <NUM> determines, in accordance with the predetermined priorities, which currently activated BWPs will be selected by the communications device <NUM> and deactivated.

The infrastructure equipment <NUM> may thus determine which, if any, BWPs will be deactivated by the communications device <NUM>, and may schedule future transmissions accordingly. For example, it may refrain from transmitting control information (such as DCI) using a data channel (such as a PDCCH) on the deactivated BWP(s)).

Because the predetermined priorities are known to both the infrastructure equipment <NUM> and the communications device <NUM>, it is not necessary for the identity (or existence) of any BWPs which are to be deactivated to be indicated in any signalling. As such, embodiments of the present technique provide a method for controlling BWPs using a relatively small amount of signalling.

Further advantages of such a priority scheme may be apparent. For example, selecting BWPs based on an index number provides a simple, unambiguous scheme, if no two BWPs share a common index number.

Selecting a BWP based on its numerology (or an aspect thereof) may ensure that either a diverse range of BWPs remains activated (if precedence is given to selecting BWPs having a numerology common to other BWPs, therefore ensuring continued support for diverse application requirements.

Alternatively, selecting a BWP based on its numerology (or an aspect thereof) may ensure that a consistent set of BWPs remains activated, therefore reducing the complexity for the ongoing operation of the communications device <NUM> since the active BWPs will have fewer different numerologies.

Selecting BWPs based on sub-carrier spacing may prioritize support (i.e. bandwidth and the corresponding data capacity) for services having particular quality of service (latency, throughput, etc.) requirements. For example, selecting for deactivation a BWP(s) having a lower sub-carrier spacing may ensure that sufficient bandwidth remains to effectively support applications or services requiring low latency transmissions.

A BWP(s) having a low remaining deactivation timer is one which, should no further data be transmitted on any activated BWPs, will be deactivated first, in response to the expiry of its associated deactivation timer. As such, prioritizing such a BWP for selection (i.e. for deactivation) may ensure that a BWP which was likely to be soon deactivated in any case (because it had not been recently used for data transmission) may avoid deactivating a more heavily (i.e. recently) used BWP.

Each BWP may have associated with it a control channel (such as a PDCCH), on which control information (such as DCI) may be transmitted. Control information may include scheduling information, indicating communications resources (for example, on a PUSCH or on a PDSCH) which have been scheduled by the infrastructure for the transmission of data to, or by, the communications device <NUM>.

Conventionally, DCI may be decoded 'blind' - that is to say, the communications device <NUM> may receive signals on the PDCCH, and may attempt to detect within those sequences predetermined patterns, corresponding to formats of DCI which may comprise information intended for it, without any a priori knowledge of whether, in fact, any DCI destined for the communications device <NUM> has been transmitted in that instance of the PDCCH. This so-called 'blind decoding' requires significant processing resources. Conventionally, a communications device <NUM> may be required to attempt to blind decode up to four DCI formats in a given PDCCH instance.

In some embodiments, when there are multiple activated BWPs, the communications device <NUM> monitors (that is, attempts blind decoding) in every instance of the PDCCH on each of the activated BWPs. In some embodiments, the PDCCH on an activated BWP may be used only to schedule transmissions on the same BWP. Alternatively, in other embodiments, a PDCCH on an activated BWP may schedule a transmission on any of the activated BWPs; in this case, the DCI may include an explicit indication of the BWP on which the scheduled communications resource is located. This provides the greatest flexibility to the infrastructure equipment <NUM>, since it provides the possibility to schedule on multiple BWPs simultaneously, with few or no constraints.

However, in such embodiments, there is the potential for the number of required blind decodes to increase according to the number of activated BWPs.

According to an example of the present technique, the communications device <NUM> attempts blind decodes on only one PDCCH. For example, the communications device <NUM> may monitor only the PDCCH associated with the primary BWP. In each slot of the primary BWP, the communications device <NUM> may attempt to blind decode DCI on the PDCCH. If DCI, comprising scheduling information intended for the communications device <NUM>, is decoded then the communications device <NUM> determines on which activated BWP the scheduled communications resources are located. This may be explicitly indicated in the DCI. Alternatively, in some embodiments, this may be implicit based on the timing of the PDCCH instance containing the DCI.

<FIG> illustrates a scheme for transmitting scheduling information to a communications device <NUM> having multiple activated BWPs, in accordance with example embodiments of the present technique.

<FIG> illustrates an example arrangement of first to third activated BWPs 801a, 801b and 801c. The first activated BWP 801a is designated as the primary BWP. According to the numerology of the primary BWP 801a, its communications resources are arranged in time slots 820a-f, and within each slot is a respective PDCCH instance 810a-f.

According to the numerology of the second activated BWP 801b, each of its slots are half of the duration of a slot of the primary BWP 801a. Similarly, each of the slots of the third activated BWP 801c are one quarter of the duration of a timeslot of the primary BWP 801a.

Each slot of the second and third BWPs 801b, 801c may comprise a PDCCH instance (not shown for conciseness and clarity).

In the example illustrated in <FIG>, the infrastructure equipment <NUM> transmits all scheduling information for the communications device <NUM> in DCI transmitted on the PDCCH of the primary BWP 801a. Thus, for example, an allocation of communications resources in a timeslot <NUM> of the second BWP 801b may be indicated in DCI transmitted in the PDCCH instance 810b of the primary BWP 801a, as indicated by the arrow <NUM>.

Similarly, an allocation of communications resources in a timeslot <NUM> of the third BWP 801c may be indicated in DCI transmitted in the PDCCH instance 810c of the primary BWP 801a, as indicated by the arrow <NUM>.

The mapping between PDCCH instance (on which DCI indicating allocated communications resources are transmitted) and BWP on which the corresponding allocated communications resources are located may be predetermined and known to both the communications device <NUM> and to the infrastructure equipment <NUM>. As such, for example, the communications device <NUM>, having decoded successfully the DCI transmitted in the PDCCH instance 810c, may determine, for example, based on the time or slot number of the slot 820c, that the DCI refers to resources on the third BWP 801c.

Because scheduling information for the communications device <NUM> for all activated BWPs 801a-c is sent on the PDCCH of a single BWP (such as the primary BWP 801a), the number of blind decode attempts required for the communications device <NUM> is significantly reduced.

In the example illustrated in <FIG>, the infrastructure equipment <NUM> transmits all scheduling information for the communications device <NUM> in DCI transmitted on the PDCCH of the primary BWP 801a; however, the present disclosure is not so limited. For example, the BWP having the shortest slot duration may be used in order to reduce a scheduling latency.

<FIG> illustrates a further scheme for transmitting scheduling information to the communications device <NUM> having multiple activated BWPs, in accordance with example embodiments of the present technique.

According to the scheme illustrated in <FIG>, at any given time (e.g. within any given time slot on a selected BWP, such as the primary BWP), the communications device <NUM> is required to decode only a single PDCCH instance. The PDCCH instance which the communications device <NUM> is required to decode (i.e. on which it may receive DCI indicating communications resource allocations) may change over time in accordance with a predetermined schedule. The schedule may be based on, for example, time slot numbers of time slots of a selected BWP, such as the primary BWP. For example, during a first slot 820a of the primary BWP, the communications device <NUM> may decode PDCCH instance 810a on the first BWP 801a. During the second slot 820b of the primary BWP 801a, the communications device <NUM> may decode PDCCH instances 850a, 850b on the second BWP 801b. During the third slot 820c of the primary BWP 801a, the communications device <NUM> may decode PDCCH instances 860a-d on the third BWP 801c. In subsequent slots of the primary BWP 801a, the pattern may repeat.

In some embodiments, multiple PDCCH instances may occur on a given BWP within a single time slot of the primary BWP 801a. In some embodiments, only a subset of (e.g. only the first) PDCCH instances on a given BWP may be decoded within a single slot of the primary BWP 801a. For example, in the third slot 820c, the communications device <NUM> may perform blind decoding only during the PDCCH instance 860a, which is the first PDCCH instance on the third BWP 801c occurring during the third time slot 820c.

The arrows <NUM>, <NUM> and <NUM> of <FIG> illustrate how DCI transmitted in PDCCH instances 810a, 850a and 860a may indicate scheduled communications resources on the same respective BWP and in the same slot.

DCI transmitted during a PDCCH which is monitored by the communications device <NUM> may conform to conventional DCI formats for transmission of scheduling information. That is, a given DCI transmitted on a PDCCH may indicated scheduled communications resources only on the BWP on which the PDCCH was transmitted.

Because the communications device <NUM> is required to only decode a single PDCCH at a given time, the number of blind decode attempts for the communications device <NUM> is significantly reduced. Furthermore, because scheduling information is transmitted on the BWP on which the scheduled resources are located, no additional information (e.g. identifying a different BWP) needs to be added to the DCI.

In some embodiments, the PDCCH(s) which are monitored by the communications device <NUM> are determined based on a capability of the communications device <NUM> indicative of the maximum number of blind decodes which the communications device <NUM> is able to perform in respect of simultaneously received signals.

For example, the communications device <NUM> may transmit an indication of the maximum number of blind decodes which the communications device <NUM> is able to perform in respect of simultaneously received signals to the infrastructure equipment <NUM>.

The communications device <NUM> determines, prior to receiving a PDCCH instance, whether the total number of simultaneous PDCCH instances (considering all activated BWPs) exceeds its capability to decode DCI from each of the simultaneous PDCCHs. If the communications device <NUM> determines that this is the case, then a subset of the activated BWPs having simultaneous PDCCHs are selected, based on a predetermined prioritisation scheme, which is known to the infrastructure equipment <NUM>. The prioritisation scheme may be selected from one or more described above in the context of BWP deactivation when the total number of activated BWPs may exceed the maximum number of activated BWPs which the communications device <NUM> can support.

Thus there has been described a communications device for communicating with an infrastructure equipment of a wireless communications network, the communications device comprising a transceiver configured to transmit signals and to receive signals on a wireless access interface of the wireless communications network using a plurality of activated bandwidth parts, each of the bandwidth parts being formed from communications resources of a carrier within a carrier bandwidth, and a processor configured to control the transceiver to transmit the signals and to receive the signals, wherein the processor is configured in combination with the transceiver to transmit signals or to receive signals using a first of the plurality of activated bandwidth parts, to receive, via the first activated bandwidth part, an indication of one or more bandwidth parts to be activated, to select one or more bandwidth parts to be de-activated in accordance with a maximum number of activated bandwidth parts permitted for the communications device, and in response to the selecting, to de-activate the selected one or more bandwidth parts.

It may be noted various example approaches discussed herein may rely on information which is predetermined / predefined in the sense of being known by both the base station and the terminal device. It will be appreciated such predetermined / predefined information may in general be established, for example, by definition in an operating standard for the wireless telecommunication system, or in previously exchanged signalling between the base station and terminal devices, for example in system information signalling, or in association with radio resource control setup signalling, or in information stored in a SIM application. That is to say, the specific manner in which the relevant predefined information is established and shared between the various elements of the wireless telecommunications system is not of primary significance to the principles of operation described herein. It may further be noted various example approaches discussed herein rely on information which is exchanged / communicated between various elements of the wireless telecommunications system and it will be appreciated such communications may in general be made in accordance with conventional techniques, for example in terms of specific signalling protocols and the type of communication channel used, unless the context demands otherwise. That is to say, the specific manner in which the relevant information is exchanged between the various elements of the wireless telecommunications system is not of primary significance to the principles of operation described herein.

It will be appreciated that the principles described herein are not applicable only to certain types of terminal device, but can be applied more generally in respect of any types of terminal device, for example the approaches are not limited to machine type communication devices / IoT devices or other narrowband terminal devices, but can be applied more generally, for example in respect of any type terminal device operating with a wireless link to the communication network.

It will further be appreciated that the principles described herein are not applicable only to LTE-based wireless telecommunications systems, but are applicable for any type of wireless telecommunications system that supports a random access procedure comprising an exchange of random access procedure messages between a terminal device and a base station.

Claim 1:
A communications device (<NUM>, <NUM>, <NUM>, <NUM>) for communicating in a wireless communications network, the communications device comprising
a transceiver (506a, 508a) configured to transmit signals and to receive signals on a wireless access interface of the wireless communications network using a plurality of currently activated bandwidth parts, each of the plurality of currently activated bandwidth parts being formed from communications resources of a carrier within a carrier bandwidth, and
a processor (506b, 508b) configured to control the transceiver to transmit the signals and to receive the signals, wherein the processor is configured in combination with the transceiver
to transmit signals or to receive signals using a first of the plurality of currently activated bandwidth parts,
to receive, via the first of the plurality of currently activated bandwidth parts, an indication of one or more other bandwidth parts to be activated,
to select one or more of the plurality of currently activated bandwidth parts to be deactivated in accordance with a maximum number of activated bandwidth parts permitted for the communications device, and
in response to the selecting, to de-activate the selected one or more of the plurality of currently activated bandwidth parts.