Patent Description:
In order to reduce control signaling overhead on a wireless link, techniques of persistent allocation of resources to a channel of the wireless link are known. Here, using a scheduling control message, resources re-occurring over time are reserved for communication on the channel. Upon a need of communicating on the channel, these re-occurring resources can be readily accessed by the transmitting device, i.e., without the need of using a further scheduling control message to implement a dedicated allocation for the respective data.

<CIT> discusses a method of transmitting and receiving data in wireless communication system.

A need exists for advanced techniques of allocating resources to channels of a wireless link.

Embodiments of the disclosure are defined by the appended claims.

In the following, the disclosure will be described in detail with reference to the accompanying drawings.

Hereinafter, techniques of wirelessly communicating using a communication network are described. The communication network may be a wireless network. For sake of simplicity, various scenarios are described hereinafter with respect to an implementation of the communication network by a cellular network. The cellular network includes multiple cells. Each cell corresponds to a respective sub-area of the overall coverage area. Other example implementations include Institute of Electrical and Electronics Engineers (IEEE) WiFi network, Multifire (see Qualcomm, "MulteFire: LTE-like performance with Wi-Fi-like deployment
simplicity. " <NPL>), etc..

Hereinafter, techniques of allocating resources to channels of a wireless link supported by an access node of the communication network are described.

A wireless link as used herein can enable communication between two or more nodes. A wireless link can enable communication using electromagnetic waves, e.g., in the MHz or GHz regime. A wireless link can support bi-directional communication. Modulation and coding of signals onto a carrier frequency can be used. A wireless link may include one or more channels. Channels may be associated with resources in the spectrum of the electromagnetic waves. Channels may be used to communicate signals and/or data of a specific kind. A wireless link can be supported by an access node of a network. For example, the access node can set certain properties of the wireless link, e.g., a timing, bandwidth etc..

Different channels of a wireless link may be between different nodes. For example, a wireless link supported by an access node may have a channel between the access node and a first terminal; and may have a further channel between access node and the second terminal. The wireless link may even have a still further channel between the first terminal and the second terminal - even for such sidelink communication the access node may set certain properties of the sidelink channel, e.g., timing, bandwidth, etc., so that also the sidelink channel of the wireless link is supported by the access node.

Implementing an allocation of resources to a channel may include refraining from communicating data on the resources which is associated with another channel. Hence, the resources may be reserved to belong to the channel. To this end, implementing an allocation of resources may include keeping track of the associations between the resources and the respective channel. Implementing an allocation can include transmission management to route data packets to the respective resources for sending and/or listening to the respective resources for receiving.

One or more scheduling control messages can be communicated to align the allocations at the transmitter and the receiver. Hence, both, the transmitting device, as well as the receiving device can implement the respective allocation.

The techniques described herein facilitate a coexistence of a persistent allocation and a dedicated allocation. Here, the persistent allocation can be associated with a plurality of resources that are re-occurring over time. The persistent allocation can be associated with a certain duration: For example, the persistent allocation can be associated with a time-out; until expiry of the time-out, the resources can be re-occurring. Such a scenario in which the persistent allocation is associated with a time-limited time duration is sometimes referred to as semi-persistent allocation. When communicating data on the channel for which the plurality of resources have been persistently allocated, it may not be required to communicate a scheduling control message which is dedicated to each specific instance of the data. Rather, resources of the plurality of resources of the persistent allocation may be readily accessed for communicating data which newly arrives in a transmit buffer, i.e., without the need of implementing a dedicated allocation upon receiving the data in a transmit buffer. In other words, a persistent allocation can be implemented without a-priori knowledge on the data that is to be communicated on the respective resources; while, in contrast, a dedicated allocation is typically implemented based on a-priori knowledge on the data that is to be communicated on the respective resources.

As a general rule, resources can be defined in at least one of frequency domain and time domain and code domain.

Resources may can be re-occurring over time if resources are repeated in accordance with a timing schedule. For example, the resources may be repeated periodically. For example, the resources may be occurring in every transmission frame or every n-th subframe, wherein n is an integer.

Frequency hopping can relate to a change of the frequency of the resources used for communicated from time to time. For example, frequency hopping can be applied for re-occurring resources of a persistent allocation. Here, the frequency can be changed from repetition to repetition or for every n-th repetition, according to a frequency hopping schedule. Resources may be defined within a resource grid of a carrier. Different resources may or may not be located in different resource grids of different carriers.

According to examples, a device implements a persistent allocation of a plurality of first resources to a first channel of a wireless link supported by an access node. Then, the device temporarily overrides the persistent allocation for a subset of the plurality of first resources and, while overriding, implements a dedicated allocation of a plurality of second resources to a second channel of the wireless link.

For example, the device may be an access node of a communication network, or a terminal (UE).

In other words, it is possible to free up capacity on the wireless link by said temporarily overriding; this capacity can then be used to accommodate for the second resources.

By such techniques it becomes possible to account for different traffic patterns associated with different channels. For example, a first traffic pattern of data that is communicated on the first channel can correspond to a steady data rate having a comparably small variability; differently, a second traffic pattern of data that is communicated on the second channel can correspond to a discontinuous data rate of large variability with pronounced peaks and dips (infrequent traffic pattern). By supporting the coexistence between the persistent allocation and the dedicated allocation, it becomes possible to tailor the balance between (i) limited-flexibility occupancy of the capacity of the wireless link associated with the persistent allocation; and (ii) increased control signaling overhead for scheduling of the dedicated allocation.

An example scenario in which such different traffic patterns are observed includes a payload channel for application data as a first channel for data associated with traffic of small variability of its data rate; and a control channel for control data as a second channel for control data associated with traffic of large variability of its data rate. This is explained in greater detail hereinafter.

For example, a wireless link typically operates within a given system bandwidth. Signaling on the wireless link may be divided into control signaling and payload signaling. For example, payload data associated with the payload signaling and communicated on a payload channel can be associated with an application layer, e.g., in accordance with then Open Systems Interface (OSI) transmission protocol stack. For example, the payload data may be defined on Layer <NUM> of an OSI transmission protocol stack. The control data associated with control signaling and communicated on a control channel can be associated with, e.g., Layer <NUM>, Layer <NUM>, or Layer <NUM> of an OSI transmission protocol stack. The control data can be for maintenance of the wireless link.

As a general rule, communication on the wireless link can be divided into broadcast signaling in which a transmitting device targets more than one receiving device; and one-to-one signaling where the transmitting device targets a dedicated receiving device. Both, payload data and control data can be associated with, both, broadcast signaling and one-to-one signaling.

Many wireless links implement frequency hopping for one or more channels. Frequency hopping corresponds to a change of the frequency for transmission, e.g., from transmission frame to transmission frame. For example, the frequency hopping may be imposed by channel access regulations - e.g., for an unlicensed band -, and/or for interference and fading mitigation - e.g., for unlicensed and licensed band operation. It has been observed that in reference implementations of a wireless link which implement frequency hopping for, both, control channels and data channels, allocating resources to the control channels significantly increases the control-signaling overhead. Thereby, the available capacity on the wireless link for the data channels is significantly reduced. For example, the capacity on the wireless link can be measured in terms of bits per Hz. This limits the throughput of payload data.

On the other hand, it has been found that certain control channels do not consume significant capacity and/or may be associated with an infrequent or non-periodic traffic pattern.

Then, by facilitating coexistence of the persistent allocation - e.g., for one or more payload channels - and the dedicated allocation - e.g., for one or more control channels - the overall throughput of data can be increased by reducing control-signaling overhead. By temporarily overriding the persistent allocation, on the other hand, capacity can be temporarily provided to accommodate resources of the dedicated allocation, to thereby support the infrequent traffic pattern associated with the traffic routed via the resources of the dedicated allocation.

Such techniques may be of particular relevance for a wireless link which employs frequency hopping, e.g., using a pseudo-random hopping pattern for one or more payload channels. Here, the dedicated allocation may be occasionally triggered in an event-driven fashion, e.g., using an event-driven signaling of control information that indicates the temporary override.

As a general rule, various types of channels are conceivable which include such an infrequent, non-periodic traffic pattern. Examples include a mobility control channel such as a paging control channel or a wake-up control channel or a control channel for data required in the preparation of handovers between cells of a cellular network, and a configuration control channel that indicates updates of operational parameters of the wireless link, e.g., updated system information.

In further detail, an example implementation of infrequent and non-periodic traffic includes wake-up signals (WUS). Such WUS techniques enable a UE to transition a main receiver of a UE into a low-power state, e.g., for power-saving purposes. In some examples, the low-power state of the main receiver may be an inactive state. For example, the WUS may be received by a dedicated low-power receiver of the UE. In other examples, the WUS may be received by the main receiver in the low-power state. Here, it may not be required to provision a dedicated low-power receiver. The low-power receiver and main receiver may be implemented within the same hardware component(s) or may be implemented by at least one different hardware component. The inactive state can be characterized by a significantly reduced power consumption if compared to an active state of the main receiver. For example, the main receiver may be unfit to receive any data in the inactive state such that some or all components may be shut down. Wake-up of the main receiver from the inactive state is then triggered by a WUS. As a general rule, the inactive state can be associated with various operational modes of the UE, e.g., a disconnected mode or idle mode; but in some scenarios also a connected mode. Sometimes, the operational mode of the UE associated with WUS communication is referred to as WUS mode. As a general rule, there may be multiple WUS modes available, e.g., modes in which the UE is registered at the network as connected or idle, etc.. When operating in a WUS mode, such UE's may only listen for a specific WUS - and may not be listening for transmitting on further channels that are active on the wireless link. In such a scenario it is conceivable that there is no persistent allocation for a wake up control channel having predefined re-occurring resources; rather, a dedicated allocation may be used for the wake up control channel. Other UE's not operating in inactive mode may not listen to the resources of the dedicated allocation to the wake up control channel.

On the other hand, an example implementation of a control channel associated with a periodic traffic pattern includes a synchronization control channel and a reference-signal control channel. Synchronization signals may be broadcasted on the synchronization control channel to provide for repeated acquiring of synchronization between UEs and the access node supporting the wireless link. A common timing reference may be provided for. To avoid for drifts and loss of synchronization, these synchronization signals are typically periodically repeated such that a persistent allocation of resources to the synchronization control channel is feasible. Further, similar considerations apply to reference signals used for channel sounding. Typically, a plurality of UEs operating in a cell may be listening for the synchronization control channel and the reference-signal control channel.

<FIG> schematically illustrates a cellular network <NUM>. The example of <FIG> illustrates the network <NUM> according to the 3GPP <NUM> architecture. Details of the fundamental architecture are described in <NPL>). While <FIG> and further parts of the following description illustrate techniques in the 3GPP <NUM> framework, similar techniques may be readily applied to different communication protocols. Examples include 3GPP LTE <NUM> and IEEE Wi-Fi technology.

In the scenario of <FIG>, a UE <NUM> is connectable to the network <NUM>. For example, the UE <NUM> may be one of the following: a cellular phone; a smart phone; an IOT device; an MTC device; a sensor; an actuator; etc..

The UE <NUM> is connectable to the network <NUM> via a radio access network (RAN) <NUM>, typically formed by one or more BSs (not illustrated in <FIG>). A wireless link <NUM> is established between the RAN <NUM> - specifically between one or more of the base stations (BSs) <NUM> of the RAN <NUM> - and the UE <NUM>. The wireless link <NUM> supports communication by implementing a multi-layer transmission protocol stack, defining the ruleset required to align the communication between participating devices <NUM>, <NUM>.

<FIG> also illustrates a further UE <NUM>. The further UE <NUM> is also connected to the network <NUM> via the wireless link <NUM> (a respective data connection is not illustrated in <FIG> for sake of simplicity). For example, the wireless link <NUM> may support multiple channels that include resources for communication of signal(s) and/or data between the BS <NUM> and each one of the UEs <NUM>, <NUM>, respectively. For example, the communication between the BS <NUM> and both of the UEs <NUM>, <NUM> may be in accordance with a common timing reference provided by the BS <NUM>; therefore, the UEs <NUM>, <NUM> share the same wireless link <NUM>. For example, a frequency reference of the wireless link <NUM> may be applicable to communication between the BS <NUM> and both UEs <NUM>, <NUM>. In general, the BS <NUM> may set the framework of communication on the wireless link <NUM> such that coexistence of multiple UEs <NUM>, <NUM> is facilitated for shared access to the wireless link <NUM>.

In the various examples described herein, the wireless link <NUM> may be implemented on an unlicensed spectrum. Multiple operators or networks may share access to the unlicensed spectrum. In other words, access to the unlicensed spectrum may not be restricted to a single operator or network. Typically, the wireless communication on the unlicensed spectrum may involve procedures and limitations due to the possibility of multiple networks sharing the same spectrum. Such techniques are sometimes also referred to as clear channel assessment techniques, e.g. Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA). Other techniques to ensure that multiple networks can share the same spectrum may include channel access regulations. Such channel access regulations may include, but are not limited to limitations on maximum percentage of transmissions per time unit (maximum channel access duty cycle), limitations on maximum transmission output power, and limitations on the maximum channel occupancy time per transmission. The required techniques may differ depending on channel access regulations for the unlicensed spectrum, and the requirements may be different depending on the specific frequency spectrum as well as the geographic location of the device. This is captured by the specific channel access regulations.

The RAN <NUM> is connected to a core network (CN) <NUM>. The CN <NUM> includes a user plane (UP) <NUM> and a control plane (CP) <NUM>. Application data is typically routed via the UP <NUM>. For this, there is provided a UP function (UPF) <NUM>. The UPF <NUM> may implement router functionality. Application data may pass through one or more UPFs <NUM>. In the scenario of <FIG>, the UPF <NUM> acts as a gateway towards a data network <NUM>, e.g., the Internet or a Local Area Network. Application data can be communicated between the UE <NUM> and one or more servers on the data network <NUM>.

The network <NUM> also includes an Access and Mobility Management Function (AMF) <NUM>; a Session Management Function (SMF) <NUM>; a Policy Control Function (PCF) <NUM>; an Application Function (AF) <NUM>; a Network Slice Selection Function (NSSF) <NUM>; an Authentication Server Function (AUSF) <NUM>; and a Unified Data Management (UDM) <NUM>. <FIG> also illustrates the protocol reference points N1-N22 between these nodes.

The AMF <NUM> provides one or more of the following functionalities: registration management; non-access stratum (NAS) termination; connection management; reachability management; mobility management; access authentication; and access authorization the AMF <NUM> can negotiate an NAS-level security context with the UE <NUM>. See <NPL>), section <NUM>. For example, the AMF <NUM> controls CN-initiated wake-up and/or paging of the UEs <NUM>: The AMF <NUM> may trigger transmission of WUS and/or paging signals of the UE <NUM>. The AMF <NUM> may keep track of the timing of a DRX cycle of the UE <NUM>.

A data connection <NUM> is established by the AMF <NUM> if the respective UE <NUM> operates in a connected mode. To keep track of the current mode of the UEs <NUM>, the AMF <NUM> sets the UE <NUM> to evolved packet system (EPS) connection management (ECM) connected or ECM idle. During ECM connected, a NAS connection is maintained between the UE <NUM> and the AMF <NUM>. The NAS connection implements an example of a mobility control connection. The NAS connection may be set up in response to wake-up and/or paging of the UE <NUM>, using a random access (RA) transmission.

The data connection <NUM> is established between the UE <NUM> via the RAN <NUM> and the DP <NUM> of the CN <NUM> and towards the DN <NUM>. For example, a connection with the Internet or another packet data network can be established. A server of the DN <NUM> may host a service for which payload data is communicated via the data connection <NUM>. The data connection <NUM> may include one or more bearers such as a dedicated bearer or a default bearer. The data connection <NUM> may be defined on the Radio Resource Control (RRC) layer, e.g., generally Layer <NUM> of the OSI model of Layer <NUM>.

The SMF <NUM> provides one or more of the following functionalities: session management including session establishment, modify and release, including bearers set up of UP bearers between the RAN <NUM> and the UPF <NUM>; selection and control of UPFs; configuring of traffic steering; roaming functionality; termination of at least parts of NAS messages; etc..

As such, the AMF <NUM> and the SMF <NUM> both implement CP mobility management needed to support a moving UE.

<FIG> illustrates aspects with respect to channels <NUM>-<NUM> implemented on the wireless link <NUM>. The wireless link <NUM> implements a plurality of communication channels <NUM>-<NUM>.

Resources - defined in time and frequency - can be allocated to the channels <NUM>-<NUM>. A scheduling control message can be used to align the time-frequency position of the allocated resources between transmitter and receiver. For example, the scheduling control message may be a Layer <NUM> control message.

To avoid collision between communication on the various channels <NUM>-<NUM>, the resources can be exclusively allocated; hence resource allocation to different channels <NUM>-<NUM> can be orthogonal with respect to each other. This may correspond to time division duplex (TDD) and frequency division duplex (FDD).

As a general rule, it is possible to defined, for each channel <NUM>-<NUM> individually, whether frequency hopping is to be used, i.e., whether to switch the resources allocated to the channel <NUM>-<NUM> over time.

As a general rule, it is possible that different resources are supported by a common carrier - e.g., by using a time-frequency resource grid defined by subcarriers and symbols in frequency and time domain, respectively. It would also be possible that different resources are supported by different carriers. For example, a narrowband carrier may be used for communication of WUSs; while a broadband carrier may be used for communication of payload data.

For example, a first channel <NUM> may carry reference signals, e.g., channel sounding reference signals and/or synchronization signals for acquiring the timing and frequency reference.

A second channel <NUM> may carry WUS which enable the network <NUM> - e.g., the AMF <NUM> (or a MME in the 3GPP LTE framework) - to wake-up the UE <NUM>. The second channel <NUM> may thus implement a wake-up control channel. The WUSs may thus be communicated in dedicated resources of the second channel <NUM>. Alternatively, the second channel <NUM> may carry paging signals,. i.e., implement a paging control channel. Generally, the second channel <NUM> may implement a mobility control channel, e.g., for coordinating handovers between multiple cells of the network, etc..

Further, a third channel <NUM> is associated with a payload signal encoding payload data. For example, payload messages carrying higher-layer user-plane data packets associated with a given service implemented by the UE <NUM> and the BS can be communicated on a payload channel, such as the third channel <NUM>. User-data messages may be transmitted via the payload channel <NUM>. Alternatively, Layer <NUM> or RRC control messages may be transmitted via the payload third channel <NUM>, e.g., a paging message. Also, scheduling control messages - e.g., DL control information (DCI) - can be communicated via the payload third channel <NUM>.

<FIG> schematically illustrates a BS <NUM> of the RAN <NUM> (cf. The BS <NUM> includes an interface <NUM>. For example, the interface <NUM> may include an analog front end and a digital front end. The BS <NUM> further includes control circuitry <NUM>, e.g., implemented by means of one or more processors and software. For example, program code to be executed by the control circuitry <NUM> may be stored in a non-volatile memory <NUM>. In the various examples disclosed herein, various functionality may be implemented by the control circuitry <NUM>, e.g.: implementing a persistent allocation; implementing a dedicated allocation; overriding the persistent allocation; etc..

<FIG> schematically illustrates the UE <NUM>. The UE <NUM> includes an interface <NUM>.

For example, the interface <NUM> may include an analog front end and a digital front end. In some examples, the interface <NUM> may include a main receiver and a low-power receiver. Each one of the main receiver and the low-power receiver may include an analog front end and a digital front end, respectively. The UE <NUM> further includes control circuitry <NUM>, e.g., implemented by means of one or more processors and software. The control circuitry <NUM> may also be at least partly implemented in hardware. For example, program code to be executed by the control circuitry <NUM> may be stored in a non-volatile memory <NUM>. In the various examples disclosed herein, various functionality may be implemented by the control circuitry <NUM>, e.g.: implementing a persistent allocation; implementing a dedicated allocation; overriding the persistent allocation; etc..

<FIG> schematically illustrates aspects with respect to persistent allocations of resources <NUM> to multiple channels <NUM> - <NUM>. Specifically, <FIG> illustrates the resources <NUM> in time and frequency domain. As illustrated in <FIG>, the resources <NUM> are spread out across a frequency band <NUM>. For example, the resources <NUM> associated with different channels <NUM> - <NUM> may be defined in a time-frequency resource grid <NUM> of one or more carriers.

As will be appreciated from <FIG>, the resources <NUM> allocated to the channels <NUM> - <NUM> do not fully occupy the spectrum within the frequency band <NUM>, but only occupy a certain sub- fraction of the spectrum. This can be due to channel access regulations - e.g., if the frequency band <NUM> resides on an unlicensed band. This can limit the maximum amount of resources <NUM> per time.

<FIG> also illustrates aspects with respect to scheduling the persistent allocations <NUM> of the resources <NUM> using a scheduling control message <NUM>. The scheduling control message <NUM> - typically a downlink (DL) control message transmitted by the BS <NUM> and received by the UE <NUM> - facilitates the implementation of the persistent allocations <NUM> of the resources <NUM> to the channels <NUM> - <NUM> at, both, the UE <NUM>, as well as at the BS <NUM>. Specifically, the allocated resources <NUM> are re-occurring over time for an extended time duration <NUM>, in the example of <FIG> with a periodicity that corresponds to the duration of transmission frames <NUM> of the transmission protocol stack implemented on the wireless link <NUM>.

<FIG> illustrates aspects with respect to a frame structure <NUM> of the transmission frames <NUM>. <FIG> illustrates the frame structure <NUM> of the transmission frames <NUM>.

The frame structure <NUM> can be generally characterized by various modalities.

As an example modality, the frame structure <NUM> defines a partition between resources <NUM> allocated to the various channels <NUM> - <NUM>. As illustrated for a further example of a transmission frame <NUM> and a transmission frame <NUM>, the frame structure <NUM> can be varied by varying the partition - e.g., in terms of distribution of resources allocated to the channels <NUM> - <NUM> and, more generally, by an amount of resources per transmission frame <NUM>-<NUM> allocated to the various channels <NUM> - <NUM> (in <FIG>, the amount of resources allocated to the second channel <NUM> is zero for the transmission frame <NUM>, but non-zero for the transmission frames <NUM>, <NUM>).

The frame structure <NUM>, as an example modality, also defines the use of a header <NUM> of the transmission frame <NUM>, <NUM>, <NUM> (the header <NUM> omitted for sake of simplicity in <FIG>). For example, the header <NUM> can include an indicator indicative of the frame structure <NUM>. Typically, the header <NUM> include Layer <NUM> control information, i.e., short and low-level control information. As example, the header may include information related to selection of modulation and coding for the frame transmission. Further it may include information indicative of the type of information in the frame, e.g. hybrid ARQ information indicating whether the payload in a frame is a first transmission or a retransmission. Further the header may include scheduling information such as control information indicative of the uplink versus downlink allocation of the frame.

The frame structure <NUM>, as a further example modality, also defines a duration <NUM> of the transmission frame <NUM>, <NUM>, <NUM>.

As a general rule, depending on the particular scenario, the frame structure <NUM> may define only a subset of these modalities and/or further modalities.

Again referring to <FIG>: By using the persistent allocation <NUM>, it is possible to communicate signal(s) and/or data <NUM> during an extended time duration <NUM> without the need of re-sending the scheduling control message <NUM> each time the signal(s) and/or data <NUM> arrive in a transmit buffer. Specifically, in <FIG>, the access of the resources <NUM> for the communication of signal(s) and/or data <NUM> on the channels <NUM> is also illustrated. As will be appreciated from <FIG>, signal(s) and/or data <NUM> are communicated on the channel <NUM> having a traffic pattern with low variability; this also applies, to some extent, to the third channel <NUM>. Differently, the traffic pattern of the signal(s) and/or data <NUM> communicated on the second channel <NUM> exhibits a significant variability. There is no periodicity associated with the occurrence of signal(s) and/or data <NUM> to be communicated on the second channel <NUM>. The reference implementation of <FIG> - which uses a persistent allocation <NUM> for the second channel <NUM> - results in an unused overhead of the resources <NUM> persistently allocated to the second channel <NUM>. In the reference implementation of <FIG>, a significant part of the resources <NUM> persistently allocated to the second channel <NUM> remains un-used (cf. arrows in <FIG>). Due to the static character of the persistent allocation <NUM> in the reference implementation of <FIG>, it is not easily possible to avoid such a waste of the resources <NUM> allocated to the second channel <NUM>.

Hereinafter, techniques are described which facilitate mitigation of such a waste of resources <NUM>, by facilitating a flexible coexistence of persistent and dedicated allocations. This helps to mitigate the disadvantages of the reference implementation as illustrated in <FIG> which exclusively employs a persistent allocation <NUM>.

To achieve this, it is possible to temporarily override the persistent allocation <NUM>; then, while overriding, it is possible to temporarily implement a dedicated allocation.

As a general rule, there are various options available for overriding the persistent allocation <NUM>. An example variant is illustrated in connection with <FIG>. This option includes adjustment of the frame structure when overriding.

<FIG> illustrates aspects with respect to the frame structure <NUM>, <NUM> of transmission frames <NUM>, <NUM>.

The transmission frame <NUM> is associated with a persistent allocation <NUM> of resources <NUM>. As such, the transmission frame <NUM> includes resources <NUM> that are persistently allocated to the channels <NUM>, <NUM>. The transmission frame <NUM> does not include any resources <NUM> allocated to the third channel <NUM>.

The transmission frame <NUM> is associated with a dedicated allocation <NUM> of resources <NUM>. As such, the transmission frame <NUM> includes resources <NUM> that are dedicatedly allocated to the second channel <NUM>. The transmission frame <NUM> does not include any resources allocated to the channels <NUM>, <NUM>.

As illustrated in <FIG>, the persistent allocation <NUM> extends beyond the length <NUM> of the transmission frame <NUM>. The persistent allocation <NUM> is natively associated with the transmission frame <NUM> of <FIG> which has a longer length <NUM>: The persistent allocation <NUM> may be expected for the transmission frame <NUM> by the receiver.

To facilitate the coexistence of persistent and dedicated allocations <NUM>, <NUM>, according to the present invention, the persistent allocation <NUM> is temporarily overridden for a subset 251A of resources <NUM>. This is achieved by replacing the transmission frame <NUM> by using the transmission frame <NUM>: the transmission frame <NUM> has a frame structure <NUM> that generally corresponds to the frame structure <NUM> of the transmission frame <NUM>, but with a shortened length <NUM> - i.e., the transmission frame <NUM> is shortened if compared to the transmission frame <NUM>. By using the shorter length <NUM> of the transmission frame <NUM>, the subset 251A is cropped from the resources <NUM> of the persistent allocation <NUM>. The resources <NUM> of the dedicated allocation <NUM> are time-aligned with the transmission gap <NUM> created by the subset 251A of resources <NUM>. Specifically, the transmission frame <NUM> is inserted into the transmission gap <NUM> created by cropping the subset 251A of resources <NUM>. Hence, the resources <NUM> of the dedicated allocation <NUM> are time-aligned (see vertical dashed lines in <FIG>) with the cropped subset 251A and the corresponding transmission gap <NUM>.

The inserted transmission frame <NUM> including the resources <NUM> of the dedicated allocation <NUM> has a frame structure <NUM> which differs from the frame structure <NUM> of, both, the transmission frame <NUM>, as well as the transmission frame <NUM> including the resources <NUM> of the persistent allocation <NUM>. Specifically, in the illustrated nonlimiting example the frame structure <NUM> differs for the transmission frames <NUM> versus <NUM>, <NUM> with respect to the following modalities: length <NUM>; and amount of resources <NUM>, <NUM> allocated to the various channels <NUM> - <NUM>. In other examples, other modalities may differ or only some of the above-identified modalities - length and amount of resources <NUM>, <NUM> - may differ.

In the illustrated example, the length <NUM> of the transmission frame <NUM> including the resources <NUM> of the dedicated allocation <NUM> is shorter if compared to the length <NUM> of the transmission frames <NUM>, <NUM> including the resources <NUM> of the persistent allocation <NUM>. In other examples, the length <NUM> of a transmission frame including resources <NUM> of the dedicated allocation <NUM> may be longer if compared to the length <NUM> of a transmission frames including the resources <NUM> of the persistent allocation <NUM>.

Further, in the illustrated example, the transmission frames <NUM>, <NUM> have a non-zero amount of resources <NUM> allocated to the channels <NUM>, <NUM>; but have a zero amount of resources <NUM> allocated to the second channel <NUM>. Differently, the transmission frame <NUM> has a zero amount of resources <NUM> allocated to the channels <NUM>, <NUM>; and has a non-zero amount of resources <NUM> allocated to the second channel <NUM>. As a general rule, beyond such strict separation of resources <NUM>, <NUM> of the various channels <NUM>-<NUM> in accordance with the persistent and dedicated allocation <NUM>, <NUM>, also mixed scenarios are conceivable in which resources <NUM> of the persistent allocation <NUM> are predominantly included in transmission frames having a first frame structure <NUM> - while resources <NUM> of the dedicated allocation <NUM> are predominantly assigned to transmission frames having a second frame structure <NUM>. Hence, the amount of resources <NUM> of the persistent allocation <NUM> can be larger for the transmission frames of the first frame structure <NUM> if compared to the transmission frames of the second frame structure <NUM>.

<FIG> schematically illustrates aspects with respect to persistent allocations of resources <NUM>, <NUM> to multiple channels <NUM> - <NUM>. Specifically, <FIG> illustrates the resources <NUM>, <NUM> in time and frequency domain.

<FIG> corresponds to an implementation of overriding the persistent allocation <NUM> by inserting the short transmission frames <NUM> into a sequence of transmission frames <NUM>, <NUM> including the resources <NUM> of the persistent allocation <NUM>. The transmission frames <NUM> include resources <NUM> of the dedicated allocation <NUM>.

<FIG> also illustrates aspects with respect to signaling the override of the persistent allocation <NUM>. In the example of <FIG>, said overriding of the persistent allocation <NUM> is signaled override control information <NUM>. For example, said overriding can be signaled using override control information <NUM> communicated using a DL control channel of the wireless link <NUM>; and/or a transmission frame header <NUM>. It would be conceivable that an indicator indicative of said overriding is included in the transmission frame header <NUM> of the transmission frames <NUM> that have the shortened length if compared to the transmission frames <NUM>. For example, for each transmission frame <NUM>, <NUM>, <NUM>, an indicator indicative of a codebook index of the respective transmission frame structure <NUM>, <NUM> or, generally, frame type, could be signaled; by switching the transmission frame structure <NUM>, <NUM>, the overriding can be implicitly signaled. In another examples, for each transmission frame <NUM>, <NUM>, the particular length <NUM> can be signaled.

In particular in a scenario in which the override control information <NUM> is not part of the frame header <NUM>, the override control information <NUM> can also be transmitted separately from the particular transmission frame affected by the overriding.

As a general rule, the override control information <NUM> indicative of said overriding can be native to a lower layer of the transmission protocol stack implemented by the wireless link <NUM> if compared to the scheduling control information <NUM>. For example, the scheduling control information <NUM> can be native to Layer <NUM>; while the override control information <NUM> can be native to Layer <NUM> - e.g., by including the override control information <NUM> as an indicator in the transmission frame header <NUM>. Thereby, low-latency override with limited control signaling becomes possible.

As a general rule, the override control information <NUM> can be indicative of a duration <NUM> of said overriding. The override control information <NUM> can be explicitly or implicitly indicative of the duration <NUM>. As an example, considering that the override control information <NUM> is included in a header <NUM> of a transmission frame <NUM>: this can implicitly indicate a duration <NUM> which corresponds to the length <NUM> of that transmission frame <NUM>. The next transmission frame <NUM>, <NUM> including resources <NUM> of the persistent allocation <NUM> may not be covered by the corresponding override control information <NUM>; but may be covered by further override control information <NUM> included in the header of the next transmission frame <NUM>, <NUM>. In other examples, the override control information can be indicative of the duration <NUM> in more explicit terms. For example, the override control information could include an indicator indicative of the duration in terms of milliseconds or a number of sequence numbers of affected transmission frames <NUM>, <NUM>, <NUM>.

The signaling of the override control information <NUM> can be event driven. For example, the event can include arrival of signal(s) and/or data <NUM> for communication on the second channel <NUM> in a transmit buffer. Then, the overriding may be event driven, in response to the need of communicating on the second channel <NUM>.

<FIG> also illustrates aspects with respect to frequency hopping. As will be appreciated from <FIG>, the frequency hopping pattern - i.e., the time-series of used frequencies - differs between the persistent allocation <NUM> and the dedicated allocation <NUM>. Specifically, the resources <NUM> of the dedicated allocation <NUM> are time-aligned with the subset 251A of cropped resources <NUM>; but use different frequencies, because of the different frequency hopping patterns.

As will be appreciated in <FIG>, the (i) override control information <NUM> and (ii) the signal(s) and/or data communicated on the second channel <NUM> may be at different frequencies and offset in frequency domain - e.g., depending on the frequency hopping pattern used for the resources <NUM> of the dedicated allocation <NUM>.

Such a technique helps to avoid a correlation between the timing of the subset 251A on the one side, and the frequencies used for communicating on the resources <NUM> of the dedicated allocation <NUM> on the other side.

A UE <NUM> intending to receive on resources <NUM> of the second channel <NUM> for which resources <NUM> are allocated by the dedicated allocation <NUM> may typically not listen for the resources <NUM> of the persistent allocation <NUM> and may therefore need advanced logic to detect or to calculate which frequency the second channel <NUM> will be allocated to. In some examples, it would even be possible that the dedicated allocation <NUM> does not use frequency hopping, but rather a fixed frequency for its resources, different to the persistent allocation <NUM>, to avoid such issues. Alternatively, a limited hopping range / simplified hopping pattern can help to simplify the logic required to detect the frequency of the resources <NUM> of the dedicated allocation <NUM> by the UE <NUM>: As illustrated, the frequency hopping range <NUM> of the resources <NUM> allocated to the third channel <NUM> by the persistent allocation <NUM> may be smaller than the frequency hopping range <NUM> of the resources <NUM> allocated to the second channel <NUM> by the dedicated allocation <NUM>. As a general rule, the frequency hopping range <NUM> can be limited to <NUM> - <NUM> frequencies for the resources <NUM> of the dedicated allocation <NUM>.

<FIG> illustrates aspects with respect to the frame structures <NUM>, <NUM> of a transmission frame <NUM>. In the example of <FIG>, the overriding is implemented within the transmission frame <NUM>. In the example of <FIG>, communication of signal(s) and/or data in the subset 251A is selectively blocked for the channels <NUM>, <NUM> (upper part of <FIG> illustrates blocking not being active, while lower part of <FIG> illustrates blocking being active). Then, these resources <NUM> of the subset 251A can be temporarily allocated to the channel <NUM>; hence, the implement the resources <NUM> of the dedicated allocation <NUM>. This corresponds to temporarily redistributing the resources <NUM> of the subset 251A from the persistent allocation <NUM> to the dedicated allocation <NUM>, thereby implementing the resources <NUM>. Thus, the frame structure <NUM> is obtained.

Specifically in such a scenario of <FIG> - in which the transmission frame <NUM> is not switched - it is possible to implement the override control information <NUM> in an implicit manner. For example DCI for communicating on the resources <NUM> allocated to the channels <NUM>, <NUM> included in the subset 251A may be omitted - thus, the DCI is not transmitted, but generally expected, this can correspond to an indication of the temporary redistribution of the respective resources <NUM> in the subset 251A from the persistent allocation <NUM> to the resources <NUM> of the dedicated allocation <NUM>. The DCI can thus be blocked from being transmitted.

<FIG> is a signaling diagram of various examples. Initially, at <NUM>, a scheduling control message <NUM> is transmitted by the BS <NUM> and received by the UE <NUM>. The scheduling control message <NUM> is indicative of the persistent allocation <NUM>.

Optionally, the scheduling control message <NUM> can also be indicative of the dedicated allocation <NUM>. For example, the scheduling control message <NUM> could be indicative of certain properties of the dedicated allocation <NUM>, e.g., the frequency hopping pattern including the frequency range <NUM>, and/or a rule set with respect to the timing of said overriding, e.g., specifying a timing relationship between communicating the overriding control information <NUM>, the activation of said overriding, and the time duration <NUM> of said overriding.

The scheduling control message <NUM> may directly activate the persistent allocation <NUM>; differently, the scheduling control message <NUM> may not directly activate the dedicated allocation <NUM>. Rather, the scheduling control message <NUM> may set a general framework of the dedicated allocation, while activation of the dedicated allocation <NUM> is handled by the override control information <NUM>.

The scheduling control message <NUM> may be a Layer <NUM> RRC control message.

As a general rule, more than a single scheduling control messages <NUM> may be communicated, e.g., at least one for the persistent allocation <NUM> and at least one for the dedicated allocation <NUM>.

Next, at <NUM>, signal(s) and/or data <NUM> of the third channel <NUM> are communicated using the resources <NUM> of the persistent allocation <NUM>, i.e., the persistent allocation <NUM> is implemented at each one of the UE <NUM> and the BS <NUM>. At <NUM>, further signal(s) and/or data <NUM> of the channel <NUM> are communicated using the resources <NUM> of the persistent allocation <NUM>, i.e., the persistent allocation <NUM> is implemented at each one of the UE <NUM> and the BS <NUM>. As a general rule, it is possible that the channels <NUM>, <NUM> for which resources are allocated by the persistent allocation <NUM> include at least one of DL channels and uplink (UL) channels (cf. <FIG>: <NUM> - UL; and <NUM> - DL).

Next, using the override control information <NUM>, at <NUM>, the persistent allocation is overridden for a time duration <NUM> and, while overriding, the dedicated allocation <NUM> is implemented: specifically, in the scenario of <FIG>, DL signal(s) and/or data <NUM> are transmitted by the BS <NUM> and received by the UE <NUM> on the resources <NUM> of the dedicated allocation <NUM>. Then, overriding completes; and, at <NUM>, <NUM>, again, signal(s) and/or data <NUM> are communicated on the resources <NUM> of the persistent allocation <NUM>.

As will be appreciated from <FIG>, generally, it would be possible that the directivity of the channels <NUM>, <NUM> for which resources are allocated by the persistent allocation <NUM> and the dedicated allocation <NUM>, respectively, is the same or different. For example, both, the persistent allocation <NUM>, as well as the dedicated allocation <NUM> could allocate UL resources <NUM> or DL resources <NUM>; other scenarios, it would be possible that the persistent allocation <NUM> includes DL resources <NUM> and the dedicated allocation <NUM> includes UL resources, or vice versa.

<FIG> is a signaling diagram. The example of <FIG> generally corresponds to the example of <FIG>. Specifically, <NUM> corresponds to <NUM>; <NUM> corresponds to <NUM>; <NUM> corresponds to <NUM>; <NUM> corresponds to <NUM>; <NUM> corresponds to <NUM>; and <NUM> corresponds to <NUM>.

In the example of <FIG>, the second channel <NUM> for which resources are allocated using the dedicated allocation <NUM> is between different end nodes than the first and third channels <NUM>, <NUM> for which resources of the persistent allocation <NUM> are used. Specifically, the second channel <NUM> is between the BS <NUM> and a second UE <NUM>.

<FIG> is a flowchart of a method according to various examples. For example, the method of <FIG> could be executed by the control circuitry <NUM>, <NUM> of the BS <NUM>. Alternatively or additionally, the method of <FIG> could be executed by the control circuitry <NUM>, <NUM> of the UE <NUM> (cf.

At block <NUM>, a persistent allocation of first resources to a first channel is implemented. This may include resolving the respective resources for use of communicating on the first channel at the transmitting device and/or the receiving device.

Optionally, at block <NUM>, signal(s) and/or data are communicated on the first resources. The signal(s) and/or data can be communicated upon arrival at a transmit buffer, without the need of additionally scheduling. For this, the first resources may be re-occurring over time such that they are ready to access upon a need of communicating the signal(s) and/or data on the first channel.

At optional block <NUM>, it is checked whether the persistent allocation should be overridden. For example, at block <NUM>, receipt of an override control information (cf. <FIG>: block <NUM>) could be monitored.

For example, the override control information can be implemented by an indication of the transmission frame type - which can be transmitted by the access node such as a BS supporting the wireless link. The procedure may involve to transmit the indication of frame type, followed by the event driven signal(s) and/or data on the same or other frequency, addressed to one or more UEs.

Other trigger criteria for activating the override are conceivable at <NUM>. For example, the activation of the override <NUM> can be event driven. For example, overriding the persistent allocation can be in response to a need of communicating data on a second channel. For this, at block <NUM>, receipt of signal(s) and/or data in a transmit buffer associated with the second channel could be monitored.

Next, at block <NUM>, the persistent allocation is temporarily overridden - e.g., for certain time duration (cf. <FIG>: time duration <NUM>).

Then, while overriding, at block <NUM>, a dedicated allocation of second resources to a second channel is implemented. This may include reserving the respective resources for communicating on the second channel at the transmitting device and/or the receiving device.

As a general rule, the first channel and the second channel can be of the same or different directivity. As a further general rule, the first channel and the second channel can be between the same or different devices. Both channels may be supported by a common access node such as a BS (cf. <FIG>, BS <NUM>).

The overriding is for a subset of the first resources. The subset of the first resources cropped from the first resources (cf. <FIG>) may be redistributed from the first resources to the second resources (cf. Cropping may include using shortened transmission frames.

Next, at optional block <NUM>, signal(s) and/or data are communicated on the second resources. This may be a broadcast or one-to-one communication.

Here, the same or different frequencies may be used for communicating if compared to a scenario in which overriding has not been triggered.

If there is a deviating frequency hopping pattern used for the persistent resources <NUM> and the dedicated resources <NUM>, the transmitting device and the receiving device adjust their receiver properties accordingly.

At optional block <NUM>, it is checked whether a timeout of the override has occurred; if not, then the override at block <NUM> is still active; otherwise, the method commences with block <NUM>.

To summarize techniques are described in which pre-allocated resources of a persistent allocation are used, e.g., for payload data channels; these resources can be re-allocated in an event-driven fashion to be used for, e.g., control signaling purpose. The re-allocation can be done by using a different frame type, or by skipping dedicated resource allocation. One particular implementation could be if the pre-allocated resources is using a frequency hopping scheme while the inserted control channel occurs in another frequency than the pre-allocated resources.

Thereby, an on-demand transmission gap can be created, e.g., for control signaling. The transmission gap can be created in a pre-allocated data transmission slot, in a frequency hopping system.

Various use cases are conceivable for such techniques.

In one example use case, the dedicated allocation is for a system that is utilizing separate WUS for idle mode UEs. Such UEs may during the idle mode only listen for a specific WUS and may not be involved in listening or transmitting on the other channels that are active within the system. In such a system the wake-up channel for communicating the WUSs may not have resources of a persistent allocation, but may be inserted in an event driven manner when there is one or more UEs to wake up. In such scenario, the WUS could be communicated in response to overriding a persistent allocation, to implement a dedicated allocation for the WUS. In such an example, UEs that are not in idle mode and that are active in the cell will not listen to the wake-up control channel when overriding.

Another example use case relates to a system operating with as little control signaling as possible. Such a system may only use a persistent allocation for periodic control signals, e.g., for synchronization signals on a synchronization control channel and perhaps a few other main signaling blocks. Any other signal(s) and/or data may be occasionally inserted when needed, by overriding the persistent allocation. Contrary to the above example of wake-up control channel using the dedicated allocation, in this example any signal(s) and/or data communicated on resources of the dedicated allocation are assumed to be received by at least some of the active devices in the cell, i.e., UEs operating in connected mode and not in idle mode.

The present invention is limited only by the scope of the appended claims.

Claim 1:
A method of operating a device (<NUM>, <NUM>, <NUM>), comprising:
- implementing (<NUM>) a persistent allocation (<NUM>) of a plurality of first resources (<NUM>) to a first channel (<NUM>, <NUM>) of a wireless link (<NUM>) supported by an access node (<NUM>), the plurality of first resources (<NUM>) being included in a sequence of first transmission frames (<NUM>, <NUM>) of a transmission protocol implemented on the wireless link (<NUM>), the first transmission frames (<NUM>, <NUM>) having at least one first frame structure (<NUM>),
- temporarily overriding (<NUM>) the persistent allocation (<NUM>) for a subset (251A) of the plurality of first resources (<NUM>), and
- while overriding (<NUM>): implementing (<NUM>) a dedicated allocation (<NUM>) of a plurality of second resources (<NUM>) to a second channel (<NUM>) of the wireless link (<NUM>), the plurality of second resources (<NUM>) being included in at least one second transmission frame (<NUM>) of the transmission protocol, the at least one second transmission frame (<NUM>) having at least one second frame structure (<NUM>) different from the at least one first frame structure (<NUM>),
wherein said overriding (<NUM>) comprises cropping the subset (251A) of the plurality of first resources (<NUM>) from the plurality of first resources (<NUM>),
the plurality of second resources (<NUM>) are time-aligned with the cropped subset (251A) of the plurality of first resources (<NUM>), and
said cropping of the subset (251A) of the plurality of first resources (<NUM>) comprises using a shortened transmission frame (<NUM>) of a transmission protocol implemented on the wireless link (<NUM>) to create a transmission gap (<NUM>) of communication on the first channel (<NUM>, <NUM>) associated with the subset (251A) of the plurality of first resources (<NUM>), and the plurality of second resources (<NUM>) is time-aligned with the transmission gap (<NUM>).