Opportunistic uplink transmission

Aspects of the present disclosure provide for opportunistic uplink transmissions within a slot. In some examples, after scheduling all regular uplink transmissions within a current slot, a base station (e.g., gNB) may identify a set of unused uplink resources within the current slot and generate and transmit unused resource information identifying the set of unused resources to the user equipment (UE) within the cell served by the base station. If a particular UE is configured to operate in an opportunistic mode, the UE may utilize the unused resource information to generate and transmit an opportunistic uplink transmission within the set of unused uplink resources.

TECHNICAL FIELD

The technology discussed below relates generally to wireless communication systems, and more particularly, to facilitating transmissions on the uplink in a wireless network.

INTRODUCTION

Wireless transmissions between a base station and one or more user equipment (UE) within a cell are generally scheduled in each subframe or slot. For example, the base station may assign resources (e.g., time-frequency resources) for downlink transmissions to one or more UEs and grant the use of resources for uplink transmissions from one or more UEs. The downlink assignments and uplink grants may be provided to the UEs via a physical downlink control channel (PDCCH).

A common form of scheduling utilized in wireless networks is dynamic scheduling, where resources are scheduled when user data traffic is available to be transmitted. For example, in the downlink (e.g., from the base station to the UE), resources may be assigned when the base station has user data traffic to send to the UE. In the uplink (e.g., from the UE to the base station), the UE may transmit a scheduling request to the base station when user data traffic arrives in the UE's uplink buffer.

While dynamic scheduling works well for bursty, infrequent, or bandwidth consuming uplink transmissions, dynamic scheduling is less ideal for low-latency uplink transmissions due to the delay and overhead requirements involved with dynamic scheduling. Therefore, other mechanisms for transmitting uplink user data traffic continue to be researched and developed.

BRIEF SUMMARY OF SOME EXAMPLES

Various aspects of the present disclosure relate to enabling opportunistic uplink transmissions within a slot. In some examples, after scheduling all regular uplink transmissions within a current slot, a scheduling entity (e.g., base station) may identify a set of unused uplink resources within the current slot and generate and transmit unused resource information identifying the set of unused resources to the scheduled entities (e.g., user equipment) within the cell served by the scheduling entity. If a particular scheduled entity is configured to operate in an opportunistic mode, the scheduled entity may utilize the unused resource information to generate and transmit an opportunistic uplink transmission within the set of unused uplink resources. The opportunistic uplink transmission may include, for example, one or more of a grant-free user data traffic transmission for urgent transmissions, a scheduling request transmission or a random access request transmission.

In one aspect of the disclosure, a method of wireless communication in a wireless communication network for a scheduling entity to communicate with a set of one or more scheduled entities is provided. The method includes identifying a set of unused uplink resources unassigned to any of the set of one or more scheduled entities within a slot, transmitting unused resource information identifying the set of unused uplink resources to the set of one or more scheduled entities, and receiving an opportunistic uplink transmission from a scheduled entity of the set of one or more scheduled entities within the set of unused uplink resources of the slot.

Another aspect of the disclosure provides a scheduling entity within a wireless communication network. The scheduling entity includes a processor, a memory communicatively coupled to the processor, and a transceiver communicatively coupled to the processor. The processor is configured to identify a set of unused uplink resources unassigned to any of a set of one or more scheduled entities within a slot, transmit unused resource information identifying the set of unused uplink resources to the set of one or more scheduled entities via the transceiver, and receive an opportunistic uplink transmission via the transceiver from a scheduled entity of the set of one or more scheduled entities within the set of unused uplink resources of the slot.

Another aspect of the disclosure provides a method of wireless communication in a wireless communication network for a scheduled entity to communicate with a scheduling entity. The method includes receiving unused resource information identifying a set of unused uplink resources within a slot. When the scheduled entity is operating in an opportunistic mode, the method further includes determining whether the set of unused uplink resources are to be utilized for an opportunistic uplink transmission, and if the set of unused uplink resources are to be utilized for an opportunistic uplink transmission, transmitting the opportunistic uplink transmission within the set of unused uplink resources of the slot.

Another aspect of the disclosure provides a scheduled entity within a wireless communication network. The scheduled entity includes a processor, a memory communicatively coupled to the process, and a transceiver communicatively coupled to the processor. The processor is configured to receive unused resource information identifying a set of unused uplink resources within a slot via the transceiver. When the scheduled entity is operating in an opportunistic mode, the processor is further configured to determine whether the set of unused uplink resources are to be utilized for an opportunistic uplink transmission, and if the set of unused uplink resources are to be utilized for an opportunistic uplink transmission, transmit the opportunistic uplink transmission within the set of unused uplink resources of the slot via the transceiver.

DETAILED DESCRIPTION

As illustrated, the RAN104includes a plurality of base stations108. Broadly, a base station is a network element in a radio access network responsible for radio transmission and reception in one or more cells to or from a UE. In different technologies, standards, or contexts, a base station may variously be referred to by those skilled in the art as a base transceiver station (BTS), a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), an access point (AP), a Node B (NB), an eNode B (eNB), a gNode B (gNB), or some other suitable terminology.

Base stations108are not the only entities that may function as scheduling entities. That is, in some examples, a UE may function as a scheduling entity, scheduling resources for one or more scheduled entities (e.g., one or more other UEs).

As illustrated inFIG. 1, a scheduling entity108may broadcast downlink traffic112to one or more scheduled entities106. Broadly, the scheduling entity108is a node or device responsible for scheduling traffic in a wireless communication network, including the downlink traffic112and, in some examples, uplink traffic116from one or more scheduled entities106to the scheduling entity108. On the other hand, the scheduled entity106is a node or device that receives downlink control information114, including but not limited to scheduling information (e.g., a grant), synchronization or timing information, or other control information from another entity in the wireless communication network such as the scheduling entity108.

In addition, the uplink and/or downlink control information and/or traffic information may be time-divided into frames, subframes, slots, and/or symbols. As used herein, a symbol may refer to a unit of time that, in an orthogonal frequency division multiplexed (OFDM) waveform, carries one resource element (RE) per sub-carrier. A slot may carry 7 or 14 OFDM symbols. A subframe may refer to a duration of lms. Multiple subframes or slots may be grouped together to form a single frame or radio frame. Of course, these definitions are not required, and any suitable scheme for organizing waveforms may be utilized, and various time divisions of the waveform may have any suitable duration.

In some examples, an unmanned aerial vehicle (UAV)220, which may be a drone or quadcopter, can be a mobile network node and may be configured to function as a UE. For example, the UAV220may operate within cell202by communicating with base station210.

In a further aspect of the RAN200, sidelink signals may be used between UEs without necessarily relying on scheduling or control information from a base station. For example, two or more UEs (e.g., UEs226and228) may communicate with each other using peer to peer (P2P) or sidelink signals227without relaying that communication through a base station (e.g., base station212). In a further example, UE238is illustrated communicating with UEs240and242. Here, the UE238may function as a scheduling entity or a primary sidelink device, and UEs240and242may function as a scheduled entity or a non-primary (e.g., secondary) sidelink device. In still another example, a UE may function as a scheduling entity in a device-to-device (D2D), peer-to-peer (P2P), or vehicle-to-vehicle (V2V) network, and/or in a mesh network. In a mesh network example, UEs240and242may optionally communicate directly with one another in addition to communicating with the scheduling entity238. Thus, in a wireless communication system with scheduled access to time-frequency resources and having a cellular configuration, a P2P configuration, or a mesh configuration, a scheduling entity and one or more scheduled entities may communicate utilizing the scheduled resources. In some examples, the sidelink signals227include sidelink traffic and sidelink control. Sidelink control information may in some examples include a request signal, such as a request-to-send (RTS), a source transmit signal (STS), and/or a direction selection signal (DSS). The request signal may provide for a scheduled entity to request a duration of time to keep a sidelink channel available for a sidelink signal. Sidelink control information may further include a response signal, such as a clear-to-send (CTS) and/or a destination receive signal (DRS). The response signal may provide for the scheduled entity to indicate the availability of the sidelink channel, e.g., for a requested duration of time. An exchange of request and response signals (e.g., handshake) may enable different scheduled entities performing sidelink communications to negotiate the availability of the sidelink channel prior to communication of the sidelink traffic information.

In the radio access network200, the ability for a UE to communicate while moving, independent of its location, is referred to as mobility. The various physical channels between the UE and the radio access network are generally set up, maintained, and released under the control of an access and mobility management function (AMF, not illustrated, part of the core network102inFIG. 1), which may include a security context management function (SCMF) that manages the security context for both the control plane and the user plane functionality, and a security anchor function (SEAF) that performs authentication.

In early 5G NR specifications, user data traffic is coded using quasi-cyclic low-density parity check (LDPC) with two different base graphs: one base graph is used for large code blocks and/or high code rates, while the other base graph is used otherwise. Control information and the physical broadcast channel (PBCH) are coded using Polar coding, based on nested sequences. For these channels, puncturing, shortening, and repetition are used for rate matching.

However, those of ordinary skill in the art will understand that aspects of the present disclosure may be implemented utilizing any suitable channel code. Various implementations of scheduling entities108and scheduled entities106may include suitable hardware and capabilities (e.g., an encoder, a decoder, and/or a CODEC) to utilize one or more of these channel codes for wireless communication.

A set of continuous or discontinuous resource blocks may be referred to herein as a Resource Block Group (RBG) or sub-band. A set of sub-bands may span the entire bandwidth. Scheduling of UEs (scheduled entities) for downlink or uplink transmissions typically involves scheduling one or more resource elements306within one or more sub-bands. Thus, a UE generally utilizes only a subset of the resource grid304. An RB may be the smallest unit of resources that can be allocated to a UE. Thus, the more RBs scheduled for a UE, and the higher the modulation scheme chosen for the air interface, the higher the data rate for the UE.

In this illustration, the RB308is shown as occupying less than the entire bandwidth of the subframe302, with some subcarriers illustrated above and below the RB308. In a given implementation, the subframe302may have a bandwidth corresponding to any number of one or more RBs308. Further, in this illustration, the RB308is shown as occupying less than the entire duration of the subframe302, although this is merely one possible example.

Although not illustrated inFIG. 3, the various REs306within a RB308may be scheduled to carry one or more physical channels, including control channels, shared channels, data channels, etc. Other REs306within the RB308may also carry pilots or reference signals, including but not limited to a demodulation reference signal (DMRS) a control reference signal (CRS), or a sounding reference signal (SRS). These pilots or reference signals may provide for a receiving device to perform channel estimation of the corresponding channel, which may enable coherent demodulation/detection of the control and/or data channels within the RB308.

In a DL transmission, the transmitting device (e.g., the scheduling entity108) may allocate one or more REs306(e.g., within a control region312) to carry DL control information including one or more DL control channels, such as a PBCH; a PSS; a SSS; a physical control format indicator channel (PCFICH); a physical hybrid automatic repeat request (HARQ) indicator channel (PHICH); and/or a physical downlink control channel (PDCCH), etc., to one or more scheduled entities. The PCFICH provides information to assist a receiving device in receiving and decoding the PDCCH. The PDCCH carries downlink control information (DCI) including but not limited to power control commands, scheduling information, a grant, and/or an assignment of REs for DL and UL transmissions. The PHICH carries HARQ feedback transmissions such as an acknowledgment (ACK) or negative acknowledgment (NACK). HARQ is a technique well-known to those of ordinary skill in the art, wherein the integrity of packet transmissions may be checked at the receiving side for accuracy, e.g., utilizing any suitable integrity checking mechanism, such as a checksum or a cyclic redundancy check (CRC). If the integrity of the transmission confirmed, an ACK may be transmitted, whereas if not confirmed, a NACK may be transmitted. In response to a NACK, the transmitting device may send a HARQ retransmission, which may implement chase combining, incremental redundancy, etc.

In an UL transmission, the transmitting device (e.g., the scheduled entity106) may utilize one or more REs306to carry UL control information including one or more UL control channels, such as a physical uplink control channel (PUCCH), to the scheduling entity. UL control information may include a variety of packet types and categories, including pilots, reference signals, and information configured to enable or assist in decoding uplink data transmissions. In some examples, the control information may include a scheduling request (SR), i.e., request for the scheduling entity to schedule uplink transmissions. Here, in response to the SR transmitted on the control channel, the scheduling entity may transmit downlink control information that may schedule resources for uplink packet transmissions. UL control information may also include HARQ feedback, channel state feedback (CSF), or any other suitable UL control information.

In addition to control information, one or more REs306(e.g., within the data region314) may be allocated for user data traffic. Such traffic may be carried on one or more traffic channels, such as, for a DL transmission, a physical downlink shared channel (PDSCH); or for an UL transmission, a physical uplink shared channel (PUSCH). In some examples, one or more REs306within the data region314may be configured to carry system information blocks (SIB s), carrying information that may enable access to a given cell.

The channels or carriers illustrated inFIG. 3are not necessarily all of the channels or carriers that may be utilized between a scheduling entity and scheduled entities, and those of ordinary skill in the art will recognize that other channels or carriers may be utilized in addition to those illustrated, such as other traffic, control, and feedback channels.

According to an aspect of the disclosure, one or more slots may be structured as self-contained slots. For example,FIGS. 4 and 5illustrate two example structures of self-contained slots400and500. The self-contained slots400and/or500may be used, in some examples, in place of the slot310described above and illustrated inFIG. 3.

FIG. 4is a diagram illustrating an example of a downlink (DL)-centric slot400according to some aspects of the disclosure. The nomenclature DL-centric generally refers to a structure wherein more resources are allocated for transmissions in the DL direction (e.g., transmissions from the scheduling entity108to the scheduled entity106). In the example shown inFIG. 4, time is illustrated along a horizontal axis, while frequency is illustrated along a vertical axis. The time-frequency resources of the DL-centric slot400may be divided into a DL burst402, a DL traffic region404and an UL burst406.

The DL burst402may exist in the initial or beginning portion of the DL-centric slot. The DL burst402may include any suitable DL information in one or more channels. In some examples, the DL burst402may include various scheduling information and/or control information corresponding to various portions of the DL-centric slot. In some configurations, the DL burst402may be a physical DL control channel (PDCCH), as indicated inFIG. 4. The DL-centric slot may also include a DL traffic region404. The DL traffic region404may sometimes be referred to as the payload of the DL-centric slot. The DL traffic region404may include the communication resources utilized to communicate DL user data traffic from the scheduling entity108(e.g., eNB) to the scheduled entity106(e.g., UE). In some configurations, the DL traffic region404may include a physical DL shared channel (PDSCH).

The UL burst406may include any suitable UL information in one or more channels. In some examples, the UL burst406may include feedback information corresponding to various other portions of the DL-centric slot. For example, the UL burst406may include feedback information corresponding to the control portion402and/or DL traffic region404. Non-limiting examples of feedback information may include an ACK signal, a NACK signal, a HARQ indicator, and/or various other suitable types of information. The UL burst406may include additional or alternative information, such as information pertaining to random access channel (RACH) procedures, scheduling requests (SRs) (e.g., within a PUCCH), and various other suitable types of information.

Here, a slot such as the DL-centric slot400may be referred to as a self-contained slot when all of the data carried in the DL traffic region404is scheduled in the control region402of the same slot; and further, when all of the data carried in the DL traffic region404is acknowledged (or at least has an opportunity to be acknowledged) in the UL burst406of the same slot. In this way, each self-contained slot may be considered a self-contained entity, not necessarily requiring any other slot to complete a scheduling-transmission-acknowledgment cycle for any given packet.

As illustrated inFIG. 4, the end of the DL traffic region404may be separated in time from the beginning of the UL burst406. This time separation may sometimes be referred to as a gap, a guard period, a guard interval, and/or various other suitable terms. This separation provides time for the switch-over from DL communication (e.g., reception operation by the scheduled entity106(e.g., UE)) to UL communication (e.g., transmission by the scheduled entity106(e.g., UE)). One of ordinary skill in the art will understand that the foregoing is merely one example of a DL-centric slot and alternative structures having similar features may exist without necessarily deviating from the aspects described herein.

FIG. 5is a diagram showing an example of an uplink (UL)-centric slot500according to some aspects of the disclosure. The nomenclature UL-centric generally refers to a structure wherein more resources are allocated for transmissions in the UL direction (e.g., transmissions from the scheduled entity106to the scheduling entity108). In the example shown inFIG. 5, time is illustrated along a horizontal axis, while frequency is illustrated along a vertical axis. The time-frequency resources of the UL-centric slot500may be divided into a DL burst502, an UL traffic region504and an UL burst506.

The DL burst502may exist in the initial or beginning portion of the UL-centric slot. The DL burst502inFIG. 5may be similar to the DL burst402described above with reference toFIG. 4. The UL-centric slot may also include an UL traffic region504. The UL traffic region504may sometimes be referred to as the payload of the UL-centric slot. The UL traffic region504may include the communication resources utilized to communicate UL user data traffic from the scheduled entity106(e.g., UE) to the scheduling entity108(e.g., eNB). In some configurations, the UL traffic region504may be a physical UL shared channel (PUSCH). As illustrated inFIG. 5, the end of the DL burst502may be separated in time from the beginning of the UL traffic region504. This time, separation may sometimes be referred to as a gap, guard period, guard interval, and/or various other suitable terms. This separation provides time for the switch-over from DL communication (e.g., reception operation by the scheduling entity106(e.g., UE)) to UL communication (e.g., transmission by the scheduling entity108(e.g., UE)).

The UL burst506inFIG. 5may be similar to the UL burst406described above with reference toFIG. 4. The UL burst506may additionally or alternatively include information pertaining to channel quality indicator (CQI), sounding reference signals (SRSs), and various other suitable types of information. One of ordinary skill in the art will understand that the foregoing is merely one example of an UL-centric slot, and alternative structures having similar features may exist without necessarily deviating from the aspects described herein.

Scheduling of uplink resources (e.g., resource elements/resource blocks) for use by scheduled entities to transmit control and/or traffic information may be performed in various ways. One such example is semi-persistent scheduling (SPS), where the scheduled entity is pre-configured by the scheduling entity with a periodicity of uplink grants. Once configured, the scheduled entity may transmit uplink transmissions at regular intervals according to the periodicity. Typically, during SPS, the resource assignments and modulation and coding scheme remain fixed for each transmission.

Another type of scheduling is referred to herein as dynamic scheduling, where resources are scheduled when data is available to be transmitted.FIG. 6is a signaling diagram600illustrating exemplary signaling for dynamic or regular scheduling according to some aspects of the present disclosure. When data arrives in an uplink buffer of a scheduled entity106, at602, the scheduled entity106may transmit a scheduling request to the scheduling entity108to request an uplink grant of time-frequency resources (e.g., resource elements/resource blocks) for the scheduled entity106to transmit the data to the scheduled entity106. The scheduling request may be transmitted, for example, via the PUCCH within an UL burst of a DL-centric slot or an UL-centric slot.

In response to the scheduling request, at604, the scheduling entity108may transmit a buffer status report (BSR) request and power headroom report (PHR) request. The BSR request and PHR request may be transmitted, for example, via the PDCCH within a DL burst of a DL-centric slot or an UL-centric slot. At606, the scheduled entity106may then transmit the BSR and PHR to the scheduling entity108. The BSR includes information on how much user data traffic is in the scheduled entity buffer waiting to be sent to the scheduling entity108. The PHR indicates how much transmission power is left for a scheduled entity to use after subtracting the power being utilized by a current transmission.

Based on the BSR and PHR, the scheduling entity108may then allocate a set of one or more resource elements (e.g. which may correspond to one or more resource blocks or resource block groups) to the scheduled entity106, and at608, transmit scheduling information corresponding to the uplink grant (e.g., information indicative of the assigned resource elements) to the scheduled entity106. The scheduling information may be transmitted, for example, via the PDCCH within a DL burst of a DL-centric slot or an UL-centric slot. In some examples, the scheduling information may be masked (scrambled) with the cell radio network temporary identifier (C-RNTI) of the scheduled entity. At610, the scheduled entity106may then utilize the assigned uplink resource element(s) to transmit the data (traffic) to the scheduling entity108via the PUSCH. The assigned uplink resources for the traffic may be within the same slot as the PDCCH carrying the scheduling information (e.g., when the PDCCH is transmitted in an UL-centric slot) or within a subsequent slot (e.g., when the PDCCH is transmitted in a DL-centric slot).

Another type of scheduling utilizes the Physical Random Access Channel (PRACH). The PRACH may be used, for example, in a random access procedure during initial access of the uplink.FIG. 7is a diagram illustrating an example of a contention based random access procedure700according to some embodiments. The random access procedure700shown inFIG. 7is initiated by the scheduled entity106randomly selecting a preamble from an available set of preambles within the cell served by the scheduling entity108, and transmitting the selected preamble to the scheduling entity108in a RACH preamble message702. In an example, the scheduled entity106may select from64possible preamble sequences for inclusion in the RACH preamble message702.

If the preamble is successfully detected by the scheduling entity108, the scheduling entity108transmits a random access response (RAR) message704to the scheduled entity106on the physical downlink control channel (PDCCH). The RAR message704includes an identifier of the preamble sent by the scheduled entity106, a Timing Advance (TA), a temporary cell radio network temporary identifier (TC-RNTI) or random access (RA) RNTI for the scheduled entity106and a grant of assigned uplink resources. Upon receipt of the RAR message704, the scheduled entity106compares the preamble ID to the preamble sent by the scheduled entity in the RACH preamble message702. If the preamble ID matches the preamble sent in the RACH preamble message702, the scheduled entity106applies the timing advance and starts a contention resolution procedure.

Since the preamble is selected randomly by the scheduled entity, if another scheduled entity selects the same preamble in the same RACH resource, a collision may result between the two scheduled entities. Any collisions may then be resolved using the contention resolution procedure. During contention resolution, the scheduled entity106transmits uplink data (traffic)706on the common control channel (CCCH) using the TA and assigned uplink resources. The uplink traffic706includes an identifier of the scheduled entity106for use by the scheduling entity in resolving any collisions. Although other scheduled entities may transmit colliding uplink transmissions utilizing the TA and assigned uplink resources, these colliding uplink transmissions will likely not be successfully decoded at the scheduling entity since the colliding uplink transmissions were transmitted with TAs that were not intended for those scheduled entities.

Upon successfully decoding the uplink traffic, the scheduling entity108transmits a contention resolution message708to the scheduled entity106. The contention resolution message708may be, for example, an RRC-Connection Setup message. In addition, the contention resolution message708includes the identifier of the scheduled entity106that was received in the uplink traffic706. The scheduled entity106, upon receiving its own identity back in the contention resolution message708, concludes that the random access procedure was successful and completes the RRC connection setup process. Any other scheduled entity receiving the RRC-Connection Setup message708with the identity of the scheduled entity106will conclude that the random access procedure failed and re-initialize the random access procedure.

Each of the above types of scheduling works well for many types of uplink transmissions. However, semi-persistent, dynamic and/or PRACH scheduling may not be ideal for low-latency (urgent) uplink transmissions that are not periodic in nature due to the delay and overhead requirements. Therefore, in accordance with various aspects of the present disclosure, instead of scheduling an uplink transmission, a scheduled entity may transmit uplink user data traffic in an opportunistic manner. To facilitate opportunistic uplink transmissions, the scheduling entity may identify a set of unused uplink resources within a slot and transmit unused resource information identifying the set of unused uplink resources within the slot. As used herein, the term unused uplink resources refers to uplink resource blocks and/or uplink resource block groups that are not scheduled and not allocated for any other use. In some examples, the unused resource information may be broadcast by the scheduling entity within the PDCCH or SIB. Upon receiving the unused resource information, a scheduled entity with user data traffic to transmit may transmit an opportunistic uplink transmission including the user data traffic within the set of unused resources to the scheduling entity.

In some examples, a scheduled entity may be configured to operate in a regular mode to schedule a regular uplink transmission (e.g., utilizing SPS, dynamic or PRACH), in an opportunistic mode to initiate an opportunistic uplink transmission, or in both the regular mode and opportunistic mode. In some examples, for the opportunistic mode-capable scheduled entities, the scheduling entity may enable or disable the opportunistic mode of those scheduled entities based on, for example, the historical uplink resource usage and/or current traffic conditions within the cell. While operating in the opportunistic mode, the scheduled entity may determine whether to initiate an opportunistic uplink transmission. For example, the scheduled entity may consider whether the scheduled entity has user data traffic to transmit to the scheduling entity, the number of resource blocks available within the set of unused uplink resources, and/or whether the scheduled entity already has a regular uplink transmission grant when determining whether to utilize the set of unused uplink resources for an opportunistic uplink transmission. In some examples, the opportunistic uplink transmission may include one or more of a contention-free PUSCH (e.g., user data traffic) transmission, a scheduling request transmission or a random access request transmission.

FIG. 8is a conceptual diagram illustrating an example of a hardware implementation for an exemplary scheduling entity800employing a processing system814. For example, the scheduling entity800may be a next generation (5G) base station as illustrated in any one or more ofFIGS. 1 and 2. In another example, the scheduling entity800may be a user equipment (UE) as illustrated in any one or more ofFIGS. 1 and 2.

The scheduling entity800may be implemented with a processing system814that includes one or more processors804. Examples of processors804include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. In various examples, the scheduling entity800may be configured to perform any one or more of the functions described herein. That is, the processor804, as utilized in a scheduling entity800, may be used to implement any one or more of the processes described below.

In this example, the processing system814may be implemented with a bus architecture, represented generally by the bus802. The bus802may include any number of interconnecting buses and bridges depending on the specific application of the processing system814and the overall design constraints. The bus802communicatively couples together various circuits including one or more processors (represented generally by the processor804), a memory805, and computer-readable media (represented generally by the computer-readable medium806). The bus802may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further. A bus interface808provides an interface between the bus802and a transceiver810. The transceiver810provides a means for communicating with various other apparatus over a transmission medium (e.g., air interface). Depending upon the nature of the apparatus, a user interface812(e.g., keypad, display, speaker, microphone, joystick) may also be provided. Of course, such a user interface812is optional, and may be omitted in some examples, such as a base station.

The processor804is responsible for managing the bus802and general processing, including the execution of software stored on the computer-readable medium806. The software, when executed by the processor804, causes the processing system814to perform the various functions described below for any particular apparatus. The computer-readable medium806and the memory805may also be used for storing data that is manipulated by the processor804when executing software.

In some aspects of the disclosure, the processor804may include circuitry configured for various functions. For example, the processor804may include resource assignment and scheduling circuitry841, configured to generate, schedule, and modify a resource assignment or grant of time-frequency resources (e.g., a set of one or more resource elements). For example, the resource assignment and scheduling circuitry841may schedule time-frequency resources within a plurality of time division duplex (TDD) and/or frequency division duplex (FDD) subframes or slots to carry user data traffic and/or control information to and/or from multiple UEs (scheduled entities).

In some examples, the resource assignment and scheduling circuitry841may be configured to schedule an uplink grant for a scheduled entity. For example, the resource assignment and scheduling circuitry841may be configured to schedule a semi-persistent scheduling (SPS) uplink grant, a dynamic uplink grant and/or a random access uplink grant. In some examples, the resource assignment and scheduling circuitry841may configure the dynamic uplink grant (e.g., allocate the set of resource elements to the dynamic uplink grant) in response to receiving a scheduling request from the scheduled entity. The resource assignment and scheduling circuitry841may further operate in coordination with resource assignment and scheduling software851.

The processor804may further include opportunistic configuration circuitry842, configured to support opportunistic uplink transmissions by scheduled entities. For example, after the resource assignment and scheduling circuitry841schedules all regular uplink transmissions (e.g., dynamic, SPS, and/or random access) within a slot (e.g., a DL-centric slot or an UL-centric slot), the opportunistic configuration circuitry842may be configured to identify any unused uplink resources (e.g., resource blocks within the PUSCH and/or PUCCH) and generate unused resource information identifying the unused uplink resources. The unused resource information may have a resource granularity of a single resource block or a resource block group. In some examples, the unused resource information may include a bit map, where each bit indicates one resource block or one resource block group that is either in use or not in use within the slot. In other examples, the unused resource information may include a set of resource block indices or resource block group indices and an indicator bit that indicates whether the resource blocks associated with the resource block indices or resource block groups associated with the resource block indices are in use or not in use. For example, the unused resource information may include b, i0, i1, i2, . . . , iN, where b is the indicator bit and i0, i1, i2, . . . , iN are the resource block or resource block group indices. In some examples, when b=0, the resource blocks or resource block groups associated with the included indices i0, i1, i2, . . . , iN are unused resources and when b=1, the resource blocks or resource block groups associated with the included indices i0, i1, i2, . . . , iN are used resources.

The set of unused uplink resources may further be divided into different resource pools, with each pool including uplink resources for a particular type of uplink transmission. Examples of uplink transmission types include PUSCH (user data traffic) uplink transmissions, scheduling request uplink transmissions, and random access request uplink transmission. The unused resource information may further indicate the particular unused uplink resources allocated to each resource pool. For example, the unused resource information may include first unused resource information identifying PUSCH resources within the set of unused uplink resources, scheduling request resources within the set of unused uplink resources, and random access channel resources within the set of unused uplink resources.

The opportunistic configuration circuitry842may further be configured to determine whether to enable or disable an opportunistic mode on each scheduled entity within the cell served by the scheduling entity. For example, the opportunistic configuration circuitry842may identify the scheduled entities within the cell that support the opportunistic mode and then enable or disable the opportunistic mode on each of those scheduled entities. The opportunistic configuration circuitry842may enable or disable the opportunistic mode based on, for example, historical uplink resource usage and/or current traffic conditions within the cell. When the opportunistic mode is disabled on a scheduled entity, the scheduled entity is prevented from transmitting opportunistic uplink transmissions, but may operate in a regular mode to transmit grant-based uplink transmissions (e.g., PUSCH, buffer status report or power headroom report). In the regular mode, the scheduled entity may further transmit scheduling requests and random access requests within regular uplink resources (e.g., uplink resources designated for scheduling requests and random access requests).

To reduce processing of opportunistic uplink transmissions, the opportunistic configuration circuitry842may further be configured to designate limited locations within the set of unused resources at which opportunistic uplink transmissions may begin. For example, the opportunistic configuration circuitry842may set a granularity of four resource blocks for each opportunistic transmission, thus requiring opportunistic uplink transmissions to start at the beginning of a four resource block (RB) section (e.g., RB0, RB4, RB8, RB12, etc.). The opportunistic configuration circuitry842may further signal a starting resource block and the resource block granularity in the unused resource information.

The processor804may further include downlink (DL) traffic and control channel generation and transmission circuitry843, configured to generate and transmit downlink user data traffic and control channels within one or more subframes or slots. The DL traffic and control channel generation and transmission circuitry843may operate in coordination with the resource assignment and scheduling circuitry841to place the DL user data traffic and/or control information onto a time division duplex (TDD) or frequency division duplex (FDD) carrier by including the DL user data traffic and/or control information within one or more subframes or slots in accordance with the resources assigned to the DL user data traffic and/or control information.

For example, the DL traffic and control channel generation and transmission circuitry843may be configured to generate a physical downlink control channel (PDCCH) (or Enhanced PDCCH (ePDCCH)) including downlink control information (DCI). In some examples, each DCI may include control information indicating an assignment of downlink resources for downlink user data traffic or a grant of uplink resources for one or more scheduled entities. The DL traffic and control channel generation and transmission circuitry843may further be configured to generate a physical downlink shared channel (PDSCH) (or Enhanced PDSCH (ePDSCH)) including downlink user data traffic.

In various aspects of the present disclosure, the DL traffic and control channel generation and transmission circuitry843may further be configured to transmit the unused resource information generated by the opportunistic configuration circuitry842for a current slot (e.g., DL-centric or UL-centric) to the scheduled entities within the cell. In some examples, the DL traffic and control channel generation and transmission circuitry843may broadcast the unused resource information within, for example, the PDCCH, a system information block (SIB), or a master information block (MIB) of a physical broadcast channel (PBCH) included within the DL burst of the current slot. For example, the DL traffic and control channel generation and transmission circuitry843may broadcast the unused resource information within the common search space for the PDCCH. The common search space consists of resource elements used for sending control information that is common to a group of scheduled entities. Thus, the common search space is monitored by all scheduled entities in a cell and is typically static between slots. Each scheduled entity may blind decode over the common search space to retrieve the unused resource information.

The DL traffic and control channel generation and transmission circuitry843may further be configured to transmit opportunistic mode information generated by the opportunistic configuration circuitry842for a scheduled entity that indicates whether to enable or disable the opportunistic mode on the scheduled entity. For example, the opportunistic mode information may include a single bit that turns on/off the opportunistic mode on the scheduled entity. The opportunistic mode information may be transmitted to the scheduled entity, for example, via RRC signaling or within a physical downlink control channel (PDCCH).

The DL traffic and control channel generation and transmission circuitry843may further be configured to generate and transmit feedback information (e.g., ACK/NACK) to a scheduled entity in response to receiving an opportunistic PUSCH uplink transmission from the scheduled entity. The DL traffic and control channel generation and transmission circuitry843may further be configured to generate and transmit an uplink grant in response to receiving an opportunistic scheduling request or a random access response in response to receiving an opportunistic random access request. For example, the DL traffic and control channel generation and transmission circuitry may transmit the feedback information for opportunistic PUSCH transmissions and the uplink grants for opportunistic scheduling request transmissions within the PDCCH (DL burst) of the next slot. The PDCCH may be scrambled with the C-RNTI of the scheduled entity. For opportunistic random access requests, the DL traffic and control channel generation and transmission circuitry843may transmit the random access response within the PDCCH of the next slot, which may be scrambled with the temporary C-RNTI (TC-RNTI) corresponding to the opportunistic random access request. The DL traffic and control channel generation and transmission circuitry843may further operate in coordination with DL traffic and control channel generation and transmission software853.

The processor804may further include uplink (UL) traffic and control channel reception and processing circuitry844, configured to receive and process uplink control channels and uplink traffic channels from one or more scheduled entities. In general, the UL traffic and control channel reception and processing circuitry844may operate in coordination with the resource assignment and scheduling circuitry841to schedule UL user data traffic transmissions, DL user data traffic transmissions and/or DL user data traffic retransmissions in accordance with the received UL control information. For example, the UL traffic and control channel reception and processing circuitry844may be configured to receive a regular dynamic scheduling request, a request for an SPS uplink grant, or a random access request from a scheduled entity. The UL traffic and control channel reception and processing circuitry844may further be configured to provide the scheduling request, SPS uplink grant request, or random access request to the resource assignment and scheduling circuitry841for processing.

The UL traffic and control channel reception and processing circuitry844may further be configured to receive regular uplink user data traffic from one or more scheduled entities. In some examples, the UL traffic and control channel reception and processing circuitry844may receive regular user data traffic from a scheduled entity within a set of resource elements allocated to the scheduled entity. For dynamic or SPS uplink grants, the UL traffic and control channel reception and processing circuitry844may receive user data traffic from the scheduled entity in accordance with the set of resource elements allocated to the dynamic or SPS uplink grant. In some examples, the scheduling information indicating the allocated set of resource elements may be included at the beginning of an UL-centric slot and the scheduled user data traffic may be received by the UL traffic and control channel reception and processing circuitry844within the same UL-centric slot.

The UL traffic and control channel reception and processing circuitry844may further be configured to receive opportunistic uplink transmissions within a set of unused uplink resources. In some examples, the opportunistic uplink transmissions may include grant-free user data traffic (e.g., grant-free PUSCH), buffer status reports, power headroom reports, scheduling requests, extended scheduling requests (e.g., multi-bit scheduling requests), and/or random access requests (e.g., PRACH). If the opportunistic uplink transmission from a scheduled entity includes user data traffic (e.g., contention-free PUSCH), the opportunistic uplink transmission may further include opportunistic transmission information at the beginning of the opportunistic uplink transmission. The opportunistic transmission information may include, for example, resource block information identifying the resource block(s) utilized for the opportunistic uplink transmission and a modulation and coding scheme (MCS) selected for the opportunistic uplink transmission. In some examples, the opportunistic transmission information may be encoded with a fixed MCS and resource block configuration to enable the UL traffic and control channel reception and processing circuitry844to identify and decode the opportunistic transmission information for use in decoding the remainder of the opportunistic uplink transmission.

If the set of unused uplink resources is divided into different resource pools, with each pool including uplink resources for a particular type of uplink transmission, each opportunistic uplink transmission received by the UL traffic and control channel reception and processing circuitry844may be received within the uplink resources designated for the particular type of opportunistic uplink transmission. For example, opportunistic PUSCH transmissions may be received within the unused resources designated for PUSCH transmissions, opportunistic scheduling request transmissions may be received within the unused resources designated for scheduling requests, and opportunistic uplink transmissions may be received within the unused resources designated for random access requests.

Since the UL traffic and control channel reception and processing circuitry844is unaware of whether an opportunistic uplink transmission exists in a current slot (e.g., DL-centric slot or UL-centric slot) or the size of the opportunistic uplink transmission, the UL traffic and control channel reception and processing circuitry844may further be configured to perform blind decoding of the unused uplink resources. To limit the number of blind decodes, and therefore reduce processing by the UL traffic and control channel reception and processing circuitry844, the opportunistic uplink transmissions may begin at designated (pre-defined) locations within the set of unused resources and may be of a preconfigured size (e.g., number of resource blocks), as determined by the starting location (e.g., starting resource block) and resource block granularity provided by the opportunistic configuration circuitry842. For example, if the opportunistic configuration circuitry842sets a granularity of four resource blocks for each opportunistic transmission, the UL traffic and control channel reception processing circuitry844may be configured to blind decode each section of four resource blocks (e.g., RB0-RB3, RB4-RB7, RB8-RB11, etc.). If more than one starting location/granularity is allowed, each opportunistic uplink transmission may further include a length-dependent demodulation reference signal (DMRS). For example, a length-dependent DMRS may include a sequence length that is dependent upon the size of the opportunistic uplink transmission, which therefore enables the UL traffic and control channel reception and processing circuitry844to detect the number of resource blocks utilized for the opportunistic uplink transmission and perform corresponding channel estimation.

In addition, to manage potential collisions between opportunistic PUSCH and scheduling request uplink transmissions, the opportunistic uplink transmissions may be code-division multiplexed with randomly selected shifts. For example, for uplink user data traffic, buffer status reports and power headroom reports, the opportunistic uplink transmissions may each include a respective DMRS that may be code-division multiplexed with DMRS of other opportunistic uplink transmissions to enable the UL traffic and control channel reception and processing circuitry844to decode each DMRS and perform channel estimation for each opportunistic uplink transmission. The UL traffic and control channel reception and processing circuitry844may then perform joint detection and demodulation of each opportunistic uplink transmission based on the respective channel estimations. Similarly, opportunistic scheduling request uplink transmissions may be code-division multiplexed with other opportunistic uplink transmissions to enable the UL traffic and control channel reception and processing circuitry844to decode the opportunistic scheduling request uplink transmissions.

If a particular scheduled entity lacks a timing advance (e.g., the DL traffic and control channel generation and transmission circuitry843has not provided the scheduled entity with a timing advance calculated by the scheduling entity800), the opportunistic uplink transmission may include an extended cyclic prefix (CP) to account for potential long propagation delays. For example, in LTE, a normal CP has a duration of 4.7 μs, while an extended CP has a duration of 16.67 μs. The CP is typically generated by copying a small part of the end of an OFDM symbol to the beginning of the OFDM symbol, which operates as a guard band between OFDM symbols to enable the UL traffic and control channel reception and processing circuitry844to identify the end of each OFDM symbol and correctly correlate multipath components of an uplink transmission. In some examples, opportunistic uplink transmissions from scheduled entities that lack timing advances may be limited to only random access opportunistic uplink transmissions. Thus, opportunistic PUSCH/scheduling request uplink transmissions may not be allowed from scheduled entities that have not been provided timing advances. The UL traffic and control channel reception and processing circuitry844may further operate in coordination with UL traffic and control channel reception and processing software854.

FIG. 9is a conceptual diagram illustrating an example of a hardware implementation for an exemplary scheduled entity900employing a processing system914. In accordance with various aspects of the disclosure, an element, or any portion of an element, or any combination of elements may be implemented with a processing system914that includes one or more processors904. For example, the scheduled entity900may be a user equipment (UE) as illustrated in any one or more ofFIGS. 1 and 2.

The processing system914may be substantially the same as the processing system814illustrated inFIG. 8, including a bus interface908, a bus902, memory905, a processor904, and a computer-readable medium906. Furthermore, the scheduled entity900may include a user interface912and a transceiver910substantially similar to those described above inFIG. 8. That is, the processor904, as utilized in a scheduled entity900, may be used to implement any one or more of the processes described below.

In some aspects of the disclosure, the processor904may include downlink (DL) traffic and control channel reception and processing circuitry941, configured for receiving and processing downlink user data traffic on a downlink traffic channel, and to receive and process control information on one or more downlink control channels. For example, the DL traffic and control channel reception and processing circuitry941may be configured to receive downlink control information (DCI) (e.g., within a PDCCH) including one or more dynamic or SPS uplink grants.

In various aspects of the present disclosure, the DL traffic and control channel reception and processing circuitry941may further be configured to receive unused resource information identifying a set of unused uplink resources within a current slot. In some examples, the unused resource information may include a bit map, where each bit indicates one resource block or one resource block group that is either in use or not in use within the slot. In other examples, the unused resource information may include a set of resource block indices or resource block group indices and an indicator bit that indicates whether the resource blocks or resource block groups associated with the set of indices are in use or not in use. The unused resource information may further indicate resource pools within the set of unused resources, with each pool including uplink resources for a particular type of uplink transmission. In addition, the unused resource information may further include a starting resource block and a resource block granularity for opportunistic uplink transmissions.

The unused resource information may be received, for example, within the PDCCH, system information block (SIB), or master information block (MIB) of a physical broadcast channel (PBCH) included within the DL burst of the current slot. For example, the DL traffic and control channel reception and processing circuitry941may receive the unused resource information within the common search space for the PDCCH. The DL traffic and control channel reception and processing circuitry941may then blind decode over the common search space to retrieve the unused resource information.

The DL traffic and control channel reception and processing circuitry941may further receive opportunistic mode information from the scheduling entity and provide the opportunistic mode information to opportunistic mode circuitry943to enable or disable the opportunistic mode on the scheduled entity900. For example, the opportunistic mode information may include a single bit that turns on/off the opportunistic mode on the scheduled entity900. When the opportunistic mode is disabled on the scheduled entity, the scheduled entity is prevented from transmitting opportunistic uplink transmissions, but may operate in a regular mode if the scheduled entity is configured to operate in a regular mode. In some aspects of the present disclosure, the scheduled entity may be configured to operate in regular mode only (e.g., opportunistic mode is not available on the scheduled entity), opportunistic mode only (e.g., regular mode is not available on the scheduled entity), or in both regular mode and opportunistic mode (e.g., when the opportunistic mode is enabled on the scheduled entity). The DL traffic and control channel reception and processing circuitry941may operate in coordination with DL traffic and control channel reception and processing software951.

The processor904may further include uplink (UL) traffic and control channel generation and transmission circuitry942, configured to generate and transmit uplink control/feedback/acknowledgement information on an UL control channel in the regular mode. For example, the UL traffic and control channel generation and transmission circuitry942may be configured to generate and transmit an uplink control channel (e.g., a Physical Uplink Control Channel (PUCCH)) on allocated uplink resources. In some examples, the UL traffic and control channel generation and transmission circuitry942may be configured to detect the presence of user data traffic in an uplink buffer (e.g., data buffer915) and to generate and transmit a dynamic scheduling request to a scheduling entity to request uplink resources (e.g., a set of one or more uplink resource elements) for transmitting the user data traffic to the scheduling entity. The UL traffic and control channel generation and transmission circuitry942may further be configured to generate and transmit a request for an SPS uplink grant for periodic transmissions. In addition, the UL traffic and control channel generation and transmission circuitry942may be configured to generate and transmit a random access request.

The UL traffic and control channel generation and transmission circuitry942may further be configured to generate and transmit uplink user data traffic on an UL traffic channel (e.g., a PUSCH) in accordance with an uplink grant in the regular mode. In some examples, the UL traffic and control channel generation and transmission circuitry942may utilize the respective allocated resources for an uplink grant to transmit uplink user data traffic in accordance with the uplink grant.

In various aspects of the present disclosure, the UL traffic and control channel generation and transmission circuitry942may further operate in coordination with the opportunistic mode circuitry943to generate and transmit an opportunistic uplink transmission when the opportunistic mode is enabled on the scheduled entity. The opportunistic uplink transmission may include grant-free user data traffic (e.g., grant-free PUSCH), buffer status reports, power headroom reports, scheduling requests, extended scheduling requests (e.g., multi-bit scheduling requests), and/or random access requests (e.g., PRACH).

The opportunistic mode circuitry943may determine whether or not to transmit uplink channels within the set of unused resources of a current slot in an opportunistic fashion based on various factors. For example, the opportunistic mode circuitry943may instruct the UL traffic and control channel generation and transmission circuitry942to generate and transmit an opportunistic uplink transmission based on the uplink traffic needs of the scheduled entity (e.g., whether the scheduled entity has uplink user data traffic in the data buffer915to transmit).

The opportunistic mode circuitry943may further consider whether the scheduled entity already has an uplink grant within the current slot to transmit uplink user data traffic when determining whether to utilize the unused uplink resources for an opportunistic uplink transmission. For example, if the scheduled entity does have an uplink grant within the current slot, the opportunistic mode circuitry943may decide to not transmit an opportunistic uplink transmission in the current slot. However, if the scheduled entity has urgent user data traffic to transmit that is not associated with the uplink grant, the opportunistic mode circuitry943may instruct the UL traffic and control channel generation and transmission circuitry942to generate and transmit the urgent user data traffic in an opportunistic uplink transmission.

The opportunistic mode circuitry943may further consider the number of resource blocks available in the set of unused resources when deciding whether to utilize the set of unused resources for an opportunistic uplink transmission. For example, if the number of resource blocks within the set of unused uplink resources is greater than a threshold and the scheduled entity has user data traffic to be transmitted to the scheduling entity, the opportunistic mode circuitry943may instruct the UL traffic and control channel generation and transmission circuitry942to generate and transmit an opportunistic uplink transmission within the set of unused resources of the current slot.

If the opportunistic uplink transmission includes user data traffic (e.g., contention-free PUSCH), the opportunistic uplink transmission may further include opportunistic transmission information at the beginning of the opportunistic uplink transmission. The opportunistic transmission information may include, for example, resource block information identifying the resource block(s) utilized for the opportunistic uplink transmission and a modulation and coding scheme (MCS) selected for the opportunistic uplink transmission. In some examples, the opportunistic transmission information may be encoded with a fixed MCS and resource block configuration to enable the scheduling entity to identify and decode the opportunistic transmission information for use in decoding the remainder of the opportunistic uplink transmission.

If the unused resource information identifies resource pools for different types of uplink transmissions, the opportunistic uplink transmission may be transmitted within the uplink resources designated for the particular type of opportunistic uplink transmission. For example, opportunistic PUSCH transmissions may be transmitted within the unused resources designated for PUSCH transmissions, opportunistic scheduling request transmissions may be transmitted within the unused resources designated for scheduling requests, and opportunistic uplink transmissions may be transmitted within the unused resources designated for random access requests.

In addition, the opportunistic uplink transmission may begin at designated (pre-defined) locations within the set of unused resources and may be of a preconfigured size (e.g., number of resource blocks), as determined by the starting location (e.g., starting resource block) and resource block granularity signaled in the unused resource information. For example, if the granularity is four resource blocks for an opportunistic uplink transmission, the UL traffic and control channel generation and transmission circuitry942may be configured to transmit the opportunistic uplink transmission within at least one set of four resource blocks of the unused uplink resources. If more than one starting location/granularity is allowed, the opportunistic uplink transmission may further include a length-dependent demodulation reference signal (DMRS), which enables the scheduling entity to detect the number of resource blocks utilized for the opportunistic uplink transmission and perform corresponding channel estimation.

In addition, the opportunistic uplink transmissions may further be code-division multiplexed with a randomly selected shift. For example, for uplink user data traffic, buffer status reports and power headroom reports, the opportunistic uplink transmissions may include a DMRS that may be code-division multiplexed with DMRS of other opportunistic uplink transmissions. Similarly, an opportunistic scheduling request uplink transmission may be code-division multiplexed with other opportunistic uplink transmissions.

In some examples, if the scheduled entity lacks a timing advance (e.g., the DL traffic and control channel reception and processing circuitry941has not received a timing advance from the scheduling entity), the opportunistic uplink transmission may include an extended cyclic prefix (CP) to account for potential long propagation delays. In other examples, the opportunistic mode circuitry943may be configured (e.g., by the scheduling entity or pre-configured) to only transmit opportunistic random access uplink transmissions when the scheduled entity lacks a timing advance. The UL traffic and control channel generation and transmission circuitry942may operate in coordination with UL traffic and control channel generation and transmission software952.

In response to an opportunistic PUSCH uplink transmission, the DL traffic and control channel reception and processing circuitry941may further be configured to receive feedback information (e.g., ACK/NACK) from the scheduling entity. The DL traffic and control channel reception and processing circuitry941may further be configured to receive an uplink grant in response to an opportunistic scheduling request or a random access response in response to an opportunistic random access request. For example, the DL traffic and control channel reception and processing circuitry941may receive the feedback information for opportunistic PUSCH transmissions and the uplink grants for opportunistic scheduling request transmissions within the PDCCH (DL burst) of the next slot. The PDCCH may be scrambled with the C-RNTI of the scheduled entity. For opportunistic random access requests, the DL traffic and control channel reception and processing circuitry941may receive the random access response within the PDCCH of the next slot, which may be scrambled with the temporary C-RNTI (TC-RNTI) corresponding to the opportunistic random access request.

FIG. 10is a diagram illustrating exemplary signaling for opportunistic uplink transmissions according to some aspects of the present disclosure. As shown inFIG. 10, when there are unused uplink resources within a current slot, the scheduling entity108may transmit unused resource information1002to the scheduled entity106. If the scheduled entity106has user data traffic to transmit to the scheduling entity108, the scheduled entity may decide to utilize the set of unused resources to transmit an opportunistic uplink transmission1004to the scheduling entity. The opportunistic uplink transmission1004may include grant-free user data traffic (e.g., grant-free PUSCH), a buffer status report, a power headroom report, a scheduling request, an extended scheduling request (e.g., multi-bit scheduling requests), and/or a random access request (e.g., PRACH).

At1008, the scheduling entity108may transmit feedback information (e.g., an ACK/NACK in response to received opportunistic uplink user data traffic), an uplink grant (e.g., in response to an opportunistic scheduling request) and/or a random access response (e.g., in response to an opportunistic random access request) to the scheduled entity106. The feedback information and/or uplink grant may be included in a PDCCH that is scrambled with the C-RNTI of the scheduled entity106. The random access response may be scrambled with the TC-RNTI corresponding to the opportunistic random access request.

FIG. 11illustrates a structure of an uplink-centric (UL-centric) slot1100including unused uplink resources according to some embodiments. In the example shown inFIG. 11, time is illustrated along a horizontal axis, while frequency is illustrated along a vertical axis. The time-frequency resources of the UL-centric slot1000may be divided into a DL burst1102, an UL traffic portion1106and an UL burst1108. A gap or guard period1104separates the end of the DL burst1102in time from the beginning of the UL traffic portion1106.

The DL burst1102may exist in the initial or beginning portion of the UL-centric slot. The DL burst1102inFIG. 11may be similar to the DL burst502described above with reference toFIG. 5. The DL burst1102of the UL-centric slot1100may also include unused resource information1110that indicates a set of unused uplink resources1112within the UL traffic portion1106and/or UL burst1108. In the example shown inFIG. 11, the set of unused uplink resources1112is within the UL traffic portion1106.

Upon receiving the unused resource information1110in the DL burst1102of the UL-centric slot1100, a scheduled entity (UE) that is enabled in the opportunistic mode may transmit an opportunistic uplink transmission within the set of unused uplink resources1112. For example, if the UE has user data traffic to transmit to the scheduling entity (base station), the UE may decide to transmit the user data traffic, a scheduling request for the user data traffic or a random access request for the user data traffic to the base station within the set of unused uplink resources1112.

FIG. 12is a flow chart illustrating an exemplary process1200for enabling opportunistic uplink transmissions in a wireless communication network according to some aspects of the present disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. In some examples, the process1200may be carried out by the scheduling entity illustrated inFIG. 8. In some examples, the process1200may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block1202, the scheduling entity may identify a set of unused uplink resources within a slot (e.g., DL-centric or UL-centric). In some examples, the scheduling entity may schedule all regular uplink transmissions (e.g., dynamic, SPS, and/or random access) within a current slot and then identify any unused uplink resources (e.g., resource blocks within the PUSCH and/or PUCCH). For example, the opportunistic configuration circuitry842, shown and described above in reference toFIG. 8, may identify the set of unused resources.

At block1204, the scheduling entity may generate and transmit unused resource information identifying the set of unused uplink resources to the scheduled entities within the cell served by the scheduling entity. For example, the unused resource information may be broadcast within the common PDCCH or SIB in the DL burst of the current slot. For example, the opportunistic configuration circuitry842together with the DL traffic and control channel generation and transmission circuitry843and transceiver810, shown and described above in reference toFIG. 8, may transmit the unused resource information.

At block1206, the scheduling entity may receive an opportunistic uplink transmission from a scheduled entity within the set of unused resources. In some examples, the opportunistic uplink transmission may include grant-free user data traffic (e.g., grant-free PUSCH), a buffer status report, a power headroom report, a scheduling request, an extended scheduling request (e.g., multi-bit scheduling requests), and/or a random access request (e.g., PRACH). For example, the UL traffic and control channel reception and processing circuitry844and transceiver810, shown and described above in reference toFIG. 8, may receive the opportunistic uplink transmission.

FIG. 13is a flow chart illustrating another exemplary process1300for enabling opportunistic uplink transmissions in a wireless communication network according to some aspects of the present disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. In some examples, the process1300may be carried out by the scheduling entity illustrated inFIG. 8. In some examples, the process1300may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block1302, the scheduling entity may determine uplink resource information, which may include historical uplink resource usage information and/or current traffic conditions. In some examples, the scheduling entity may determine a number or average number of unused uplink resource blocks (or a percentage or average percentage of unused uplink resource blocks) over a period of time (e.g., one or more consecutive slots, selected slots, historical data based on time of day, etc.). For example, the opportunistic configuration circuitry842, shown and described above in reference toFIG. 8, may determine the uplink resource usage information.

At block1304, the scheduling entity may generate and transmit opportunistic mode information based on the uplink resource information. The opportunistic mode information may indicate whether to enable or disable the opportunistic mode on one or more scheduled entities. In some examples, the scheduling entity may compare the uplink resource information to a threshold to determine the congestion (or historical congestion) in the cell and may set the opportunistic mode information to enable the opportunistic mode on the one or more scheduled entities when congestion in the cell is low. For example, the opportunistic configuration circuitry842, shown and described above in reference toFIG. 8, may determine whether to enable the opportunistic mode.

If the scheduling entity determines to set the opportunistic mode information to disable the opportunistic mode (N branch of block1306), at block1308, the scheduling entity prevents opportunistic uplink transmissions in the cell. For example, the scheduling entity may transmit the opportunistic mode information including a single bit that turns off the opportunistic mode on scheduled entities in the cell. The opportunistic mode information may be transmitted to scheduled entities, for example, via RRC signaling or within a physical downlink control channel (PDCCH). When the opportunistic mode is disabled on a scheduled entity, the scheduled entity may still operate in a regular mode to transmit grant-based uplink transmissions (e.g., PUSCH, buffer status report or power headroom report), scheduling requests and random access requests within regular uplink resources (e.g., uplink resources designated for scheduling requests and random access requests). For example, the opportunistic configuration circuitry842, shown and described above in reference toFIG. 8, may prevent opportunistic uplink transmissions in the cell.

If the scheduling entity determines to set the opportunistic mode information to enable the opportunistic mode (Y branch of block1306), at block1310, the scheduling entity may identify a set of unused uplink resources within a slot (e.g., DL-centric or UL-centric). In some examples, the scheduling entity may schedule all regular uplink transmissions (e.g., dynamic, SPS, and/or random access) within a current slot and then identify any unused uplink resources (e.g., resource blocks within the PUSCH and/or PUCCH). For example, the opportunistic configuration circuitry842, shown and described above in reference toFIG. 8, may identify the set of unused resources.

At block1312, the scheduling entity may generate and transmit unused resource information identifying the set of unused uplink resources to the scheduled entities within the cell served by the scheduling entity. For example, the unused resource information may be broadcast within the common PDCCH or SIB in the DL burst of the current slot. For example, the opportunistic configuration circuitry842together with the DL traffic and control channel generation and transmission circuitry843and transceiver810, shown and described above in reference toFIG. 8, may transmit the unused resource information.

At block1314, the scheduling entity may receive an opportunistic uplink transmission from a scheduled entity within the set of unused resources. In some examples, the opportunistic uplink transmission may include grant-free user data traffic (e.g., grant-free PUSCH), a buffer status report, a power headroom report, a scheduling request, an extended scheduling request (e.g., multi-bit scheduling requests), and/or a random access request (e.g., PRACH). For example, the UL traffic and control channel reception and processing circuitry844and transceiver810, shown and described above in reference toFIG. 8, may receive the opportunistic uplink transmission.

FIG. 14is a flow chart illustrating another exemplary process1400for enabling opportunistic uplink transmissions in a wireless communication network according to some aspects of the present disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. In some examples, the process1400may be carried out by the scheduling entity illustrated inFIG. 8. In some examples, the process1400may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block1402, the scheduling entity may identify a set of unused uplink resources within a slot (e.g., DL-centric or UL-centric). In some examples, the scheduling entity may schedule all regular uplink transmissions (e.g., dynamic, SPS, and/or random access) within a current slot and then identify any unused uplink resources (e.g., resource blocks within the PUSCH and/or PUCCH). For example, the opportunistic configuration circuitry842shown and described above in reference toFIG. 8may identify the set of unused resources.

At block1404, the scheduling entity may generate and transmit unused resource information identifying the set of unused uplink resources to the scheduled entities within the cell served by the scheduling entity. For example, the unused resource information may be broadcast within the common PDCCH or SIB in the DL burst of the current slot. In addition, the unused resource information may indicate the resource block granularity allowed for opportunistic uplink transmissions and pre-defined starting locations within the set of unused resources that opportunistic uplink transmissions may begin. For example, the opportunistic configuration circuitry842together with the DL traffic and control channel generation and transmission circuitry843and transceiver810shown and described above in reference toFIG. 8, may transmit the unused resource information.

At block1406, the scheduling entity may receive an opportunistic uplink transmission from a scheduled entity starting at a predefined location within the set of unused resources. In some examples, the opportunistic uplink transmission may include grant-free user data traffic (e.g., grant-free PUSCH), a buffer status report, a power headroom report, a scheduling request, an extended scheduling request (e.g., multi-bit scheduling requests), and/or a random access request (e.g., PRACH). If more than one starting location/granularity is allowed, the opportunistic uplink transmission may further include a length-dependent demodulation reference signal (DMRS). For example, the UL traffic and control channel reception and processing circuitry844and transceiver810shown and described above in reference toFIG. 8, may receive the opportunistic uplink transmission.

At block1408, the scheduling entity may detect the opportunistic uplink transmission based on the length-dependent DMRS. For example, the length-dependent DMRS may include a sequence length that is dependent upon the size of the opportunistic uplink transmission, which therefore enables the UL traffic and control channel reception and processing circuitry844, shown and described above in reference toFIG. 8, to detect the number of resource blocks utilized for the opportunistic uplink transmission and perform corresponding channel estimation.

FIG. 15is a flow chart illustrating another exemplary process1500for enabling opportunistic uplink transmissions in a wireless communication network according to some aspects of the present disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. In some examples, the process1500may be carried out by the scheduling entity illustrated inFIG. 8. In some examples, the process1500may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block1502, the scheduling entity may identify a set of unused uplink resources within a slot (e.g., DL-centric or UL-centric). In some examples, the scheduling entity may schedule all regular uplink transmissions (e.g., dynamic, SPS, and/or random access) within a current slot and then identify any unused uplink resources (e.g., resource blocks within the PUSCH and/or PUCCH). For example, the opportunistic configuration circuitry842, shown and described above in reference toFIG. 8, may identify the set of unused resources.

At block1504, the scheduling entity may generate and transmit unused resource information identifying the set of unused uplink resources to the scheduled entities within the cell served by the scheduling entity. For example, the unused resource information may be broadcast within the common PDCCH or SIB in the DL burst of the current slot. For example, the opportunistic configuration circuitry842together with the DL traffic and control channel generation and transmission circuitry843and transceiver810, shown and described above in reference toFIG. 8, may transmit the unused resource information.

At block1506, the scheduling entity may schedule an uplink grant of scheduled uplink resources to a scheduled entity in the slot. For example, the resource assignment and scheduling circuitry841, shown and described above in reference toFIG. 8, may schedule a semi-persistent scheduling (SPS) uplink grant, a dynamic uplink grant and/or a random access uplink grant. In some examples, the resource assignment and scheduling circuitry841may further configure the dynamic uplink grant (e.g., allocate the set of resource elements to the dynamic uplink grant) in response to receiving a scheduling request from the scheduled entity.

At block1508, the scheduling entity may transmit scheduling information indicating the scheduled uplink resources to the scheduled entity. For example, the DL traffic and control channel generation and transmission circuitry843and transceiver810, shown and described above in reference toFIG. 8, may generate and transmit a physical downlink control channel (PDCCH) (or Enhanced PDCCH (ePDCCH)) including downlink control information (DCI) indicating a grant of uplink resources for the scheduled entity.

At block1510, the scheduling entity may receive the scheduled uplink transmission from the scheduled entity utilizing the scheduled uplink resources. For example, the UL traffic and control channel reception and processing circuitry844and transceiver810, shown and described above in reference toFIG. 8, may receive user data traffic from a scheduled entity within the scheduled uplink resources. For dynamic or SPS uplink grants, the UL traffic and control channel reception and processing circuitry844may receive user data traffic from the scheduled entity in accordance with the set of resource elements allocated to the dynamic or SPS uplink grant.

At block1512, the scheduling entity may further receive an opportunistic uplink transmission from the same scheduled entity within the set of unused resources. In some examples, the opportunistic uplink transmission may include grant-free user data traffic (e.g., grant-free PUSCH), a buffer status report, a power headroom report, a scheduling request, an extended scheduling request (e.g., multi-bit scheduling requests), and/or a random access request (e.g., PRACH). For example, the UL traffic and control channel reception and processing circuitry844and transceiver810, shown and described above in reference toFIG. 8, may receive the opportunistic uplink transmission.

FIG. 16is a flow chart illustrating another exemplary process1600for enabling opportunistic uplink transmissions in a wireless communication network according to some aspects of the present disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. In some examples, the process1600may be carried out by the scheduling entity illustrated inFIG. 8. In some examples, the process1600may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block1602, the scheduling entity may identify a set of unused uplink resources within a slot (e.g., DL-centric or UL-centric). In some examples, the scheduling entity may schedule all regular uplink transmissions (e.g., dynamic, SPS, and/or random access) within a current slot and then identify any unused uplink resources (e.g., resource blocks within the PUSCH and/or PUCCH). For example, the opportunistic configuration circuitry842, shown and described above in reference toFIG. 8, may identify the set of unused resources.

At block1604, the scheduling entity may generate and transmit unused resource information identifying the set of unused uplink resources to the scheduled entities within the cell served by the scheduling entity. For example, the unused resource information may be broadcast within the common PDCCH or SIB in the DL burst of the current slot. For example, the opportunistic configuration circuitry842together with the DL traffic and control channel generation and transmission circuitry843and transceiver810, shown and described above in reference toFIG. 8, may transmit the unused resource information.

At block1606, the scheduling entity may receive an opportunistic uplink transmission from a scheduled entity within the set of unused resources. In some examples, the opportunistic uplink transmission may include grant-free user data traffic (e.g., grant-free PUSCH), a buffer status report, a power headroom report, a scheduling request, an extended scheduling request (e.g., multi-bit scheduling requests), and/or a random access request (e.g., PRACH). For example, the UL traffic and control channel reception and processing circuitry844and transceiver810, shown and described above in reference toFIG. 8, may receive the opportunistic uplink transmission.

At block1608, the scheduling entity may transmit feedback information for the opportunistic transmission. For example, the DL traffic and control channel generation and transmission circuitry843, shown and described above in reference toFIG. 8, may generate and transmit an ACK/NACK in response to received opportunistic uplink user data traffic, an uplink grant (e.g., in response to an opportunistic scheduling request) and/or a random access response (e.g., in response to an opportunistic random access request) to the scheduled entity. The ACK/NACK and/or uplink grant may be included in a PDCCH that is scrambled with the C-RNTI of the scheduled entity. The random access response may be scrambled with the TC-RNTI corresponding to the opportunistic random access request.

FIG. 17is a flow chart illustrating an exemplary process1700for performing opportunistic uplink transmissions in a wireless communication network according to some aspects of the present disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. In some examples, the process1700may be carried out by the scheduled entity illustrated inFIG. 9. In some examples, the process1700may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block1702, the scheduled entity may receive unused resource information identifying a set of unused uplink resources within a slot (e.g., a DL-centric slot or UL-centric slot). For example, the unused resource information may be broadcast within the common PDCCH or SIB in the DL burst of the current slot. For example, the DL traffic and control channel reception and processing circuitry941, shown and described above in reference toFIG. 9, may receive the unused resource information.

At block1704, the scheduled entity may determine whether the set of unused uplink resources should be used for an opportunistic uplink transmission. For example, the scheduled entity may consider whether the scheduled entity has user data traffic to transmit to the scheduling entity, the number of resource blocks available within the set of unused uplink resources, and/or whether the scheduled entity already has a regular uplink transmission grant when determining whether to utilize the set of unused uplink resources for an opportunistic uplink transmission. For example, the opportunistic mode circuitry943, shown and described above in reference toFIG. 9, may determine whether to utilize the set of unused uplink resources for an opportunistic uplink transmission.

If the scheduled entity determines to utilize the set of unused uplink resources for an opportunistic uplink transmission (Y branch of block1706), at block1708, the scheduled entity may generate and transmit an opportunistic uplink transmission within the set of unused uplink resources. In some examples, the opportunistic uplink transmission may include one or more of a contention-free PUSCH (e.g., user data traffic) transmission, a scheduling request transmission or a random access request transmission. For example, the opportunistic mode circuitry943together with the UL traffic and control channel generation and transmission circuitry942, shown and described above in reference toFIG. 9, may generate and transmit the opportunistic uplink transmission.

FIG. 18is a flow chart illustrating another exemplary process1800for performing opportunistic uplink transmissions in a wireless communication network according to some aspects of the present disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. In some examples, the process1800may be carried out by the scheduled entity illustrated inFIG. 9. In some examples, the process1800may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block1802, the scheduled entity may receive unused resource information identifying a set of unused uplink resources within a slot (e.g., a DL-centric slot or UL-centric slot). For example, the unused resource information may be broadcast within the common PDCCH or SIB in the DL burst of the current slot. For example, the DL traffic and control channel reception and processing circuitry941, shown and described above in reference toFIG. 9, may receive the unused resource information.

At block1804, the scheduled entity may determine whether the number of resource blocks available within the set of unused uplink resources is greater than a threshold. For example, the opportunistic mode circuitry943, shown and described above in reference toFIG. 9, may determine whether the number of resource blocks in the set of unused uplink resources is greater than the threshold.

If the number of resource blocks within the set of unused uplink resources is greater than the threshold (Y branch of block1804), at block1806, the scheduled entity may determine whether the scheduled entity has user data traffic to transmit to the scheduling entity. For example, the UL traffic and control channel generation and transmission circuitry942together with the opportunistic mode circuitry943, shown and described above in reference toFIG. 9, may determine whether there is user data traffic to transmit.

If the scheduled entity determines that there is user data traffic to transmit (Y branch of block1806), at block1808, the scheduled entity may generate and transmit an opportunistic uplink transmission within the set of unused uplink resources. In some examples, the opportunistic uplink transmission may include one or more of a contention-free PUSCH (e.g., user data traffic) transmission, a scheduling request transmission or a random access request transmission. For example, the opportunistic mode circuitry943together with the UL traffic and control channel generation and transmission circuitry942, shown and described above in reference toFIG. 9, may generate and transmit the opportunistic uplink transmission.

FIG. 19is a flow chart illustrating another exemplary process1900for performing opportunistic uplink transmissions in a wireless communication network according to some aspects of the present disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. In some examples, the process1900may be carried out by the scheduled entity illustrated inFIG. 9. In some examples, the process1900may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block1902, the scheduled entity may receive unused resource information identifying a set of unused uplink resources within a slot (e.g., a DL-centric slot or UL-centric slot). For example, the unused resource information may be broadcast within the common PDCCH or SIB in the DL burst of the current slot. For example, the DL traffic and control channel reception and processing circuitry941, shown and described above in reference toFIG. 9, may receive the unused resource information.

At block1904, the scheduled entity may determine whether the scheduled entity has already received a grant for a scheduled uplink transmission and also has additional urgent user data traffic to transmit. For example, the UL traffic and control channel generation and transmission circuitry942together with the opportunistic mode circuitry943, shown and described above in reference toFIG. 9, may determine whether there is additional urgent user data traffic to transmit that is not associated with the uplink grant.

If the scheduled entity determines that there is additional urgent user data traffic to transmit that is not associated with the uplink grant (Y branch of block1904), at block1906, the scheduled entity may generate and transmit an opportunistic uplink transmission within the set of unused uplink resources. In some examples, the opportunistic uplink transmission may include a contention-free PUSCH (e.g., user data traffic) transmission. For example, the opportunistic mode circuitry943together with the UL traffic and control channel generation and transmission circuitry942, shown and described above in reference toFIG. 9, may generate and transmit the opportunistic uplink transmission.

FIG. 20is a flow chart illustrating another exemplary process2000for performing opportunistic uplink transmissions in a wireless communication network according to some aspects of the present disclosure. As described below, some or all illustrated features may be omitted in a particular implementation within the scope of the present disclosure, and some illustrated features may not be required for implementation of all embodiments. In some examples, the process2000may be carried out by the scheduled entity illustrated inFIG. 9. In some examples, the process2000may be carried out by any suitable apparatus or means for carrying out the functions or algorithm described below.

At block2002, the scheduled entity may receive opportunistic mode information from a scheduling entity. For example, the opportunistic mode information may include a single bit that turns on/off the opportunistic mode on the scheduled entity. The opportunistic mode information may be received, for example, via RRC signaling or within a physical downlink control channel (PDCCH). For example, the DL traffic and control channel reception and processing circuitry941, shown and described above in reference toFIG. 9, may receive the opportunistic mode information.

At block2004, the scheduled entity may determine whether the opportunistic mode is enabled based on the opportunistic mode information. For example, the opportunistic mode circuitry943, shown and described above in reference toFIG. 9, may determine whether the opportunistic mode is enabled.

If the opportunistic mode is disabled (N branch of block2004), at block2006, the scheduled entity may be prevented from generating and transmitting opportunistic uplink transmissions. When the opportunistic mode is disabled on the scheduled entity, the scheduled entity is prevented from transmitting opportunistic uplink transmissions, but may operate in a regular mode if the scheduled entity is configured to operate in a regular mode. For example, the opportunistic mode circuitry943, shown and described above in reference toFIG. 9, may prevent the scheduled entity from generating and transmitting opportunistic uplink transmissions when the opportunistic mode is disabled.

If the opportunistic mode is enabled (Y branch of block2004), at block2008, the scheduled entity may receive unused resource information identifying a set of unused uplink resources within a slot (e.g., a DL-centric slot or UL-centric slot). For example, the unused resource information may be broadcast within the common PDCCH or SIB in the DL burst of the current slot. For example, the DL traffic and control channel reception and processing circuitry941, shown and described above in reference toFIG. 9, may receive the unused resource information.

At block2010, the scheduled entity may determine whether the set of unused uplink resources should be used for an opportunistic uplink transmission. For example, the scheduled entity may consider whether the scheduled entity has user data traffic to transmit to the scheduling entity, the number of resource blocks available within the set of unused uplink resources, and/or whether the scheduled entity already has a regular uplink transmission grant when determining whether to utilize the set of unused uplink resources for an opportunistic uplink transmission. For example, the opportunistic mode circuitry943, shown and described above in reference toFIG. 9, may determine whether to utilize the set of unused uplink resources for an opportunistic uplink transmission.

If the scheduled entity determines to utilize the set of unused uplink resources for an opportunistic uplink transmission (Y branch of block2012), at block2014, the scheduled entity may generate and transmit an opportunistic uplink transmission within the set of unused uplink resources. In some examples, the opportunistic uplink transmission may include one or more of a contention-free PUSCH (e.g., user data traffic) transmission, a scheduling request transmission or a random access request transmission. For example, the opportunistic mode circuitry943together with the UL traffic and control channel generation and transmission circuitry942, shown and described above in reference toFIG. 9, may generate and transmit the opportunistic uplink transmission.