JP7315769B2 - integrated circuit - Google Patents

Description

The present disclosure relates to configuring control resource sets in networks with complex numerologies and capabilities of communication devices and corresponding integrated circuits.

Currently, the 3rd Generation Partnership Project (3GPP) is working on technical specifications for the next release (Release 15) for the next generation cellular technology, also called 5th Generation (5G). At the 71st Radio Access Network (RAN) meeting of the 3GPP Technical Specification Group (TSG) (Gothenburg, March 2016), the first 5G work item "Study on New Radio Access Technologies", which includes RAN1, RAN2, RAN3 and RAN4, was approved and is considered to be a Release 15 work item defining the first 5G standards.

The purpose of this study item is to develop a “New Radio (NR) Access Technology”, which operates at frequencies up to 100 GHz and supports a wide range of use cases as defined during the RAN requirements review (see, e.g., Non-Patent Document 1, current version 14.0.0, available at www.3gpp.org and incorporated herein in its entirety by reference).

One objective is to provide a single technology framework that addresses all usage scenarios, requirements, and deployment scenarios defined in Non-Patent Document 1, including at least Enhanced Mobile Broadband (eMBB), Ultra Reliable Low Latency Communications (URLLC), and Massive Machine Type Communications (mMTC). For example, eMBB deployment scenarios can include indoor hotspots, dense urban, rural, urban macro, high speed, etc., and URLLC deployment scenarios can include industrial control systems, mobile healthcare (remote monitoring, diagnostics and therapy), real-time control of vehicles, wide area monitoring and control systems for smart grids, while mMTC has multiple device scenarios with non-time-critical data transfer such as smart wearables and sensor networks. can be included.

A second goal is forward compatibility. Backward compatibility with Long Term Evolution (LTE) is not required, which encourages completely new system designs and/or introduction of new features.

The basic physical layer signaling will be based on orthogonal frequency division multiplexing (OFDM) to support non-orthogonal waveforms and multiple access as much as possible. Additional features to OFDM are being considered, for example Discrete Fourier Transform (DFT) Spread OFDM (DFT-S-OFDM), and/or variants of DFT-S-OFDM, and/or filtering/windowing. In LTE, cyclic prefix (CP)-based OFDM and DFT-S-OFDM are used as waveforms for downlink and uplink transmissions, respectively. One of the design goals in NR is to seek as common waveforms as possible for downlink, uplink and sidelink. It is believed that the introduction of DFT spreading may not be required in some cases of uplink transmission. The term "downlink" refers to communication from a higher node to a lower node (eg, base station to relay node or UE, relay node to UE, etc.). The term "uplink" refers to communication from a lower node to a higher node (eg, UE to relay node or base station, relay node to base station, etc.). The term "sidelink" refers to communication between nodes at the same level (eg, between two UEs, or between two relay nodes, or between two base stations).

In addition to waveforms, several basic frame structures and channel coding schemes are under development to achieve the goals mentioned above. As identified in [1], different use cases/deployment scenarios of NR have different requirements in terms of data rate, latency and coverage. For example, eMBB is envisioned to support peak data rates (20 Gbps for downlink and 10 Gbps for uplink) and user perceived data rates that are approximately three times the speed offered by International Mobile Telecommunications-Advanced (IMT-Advanced). On the other hand, for URLLC, more stringent requirements are imposed for ultra-low latency (0.5 ms each for UL and DL for user plane latency) and high reliability. Finally, mMTC demands high connection density (1,000,000 devices/km2 in urban environments), extensive coverage in harsh environments, and extremely long battery life (15 years) for low cost devices.

Thus, OFDM numerology (eg, subcarrier spacing, OFDM symbol period, CP period) and number of symbols per scheduling interval that are suitable for one use case may not work well for another use case. For example, low-latency applications may require shorter OFDM symbol periods (larger subcarrier spacing) and/or fewer symbols per scheduling interval (also called transmission time interval (TTI)) compared to mMTC applications. Furthermore, deployment scenarios with large channel delay spreads require longer CP periods than scenarios with short delay spreads. Therefore, subcarrier spacing should be optimized to maintain similar CP overhead.

At the 3GPP RAN1#84bis meeting (Busan, April 2016), it was agreed that NR should support multiple values of subcarrier spacing. The subcarrier spacing value is derived from a specific value of the subcarrier spacing multiplied by N, where N is an integer scaling factor. At the 3GPP RAN1#85 meeting (Nanjing, May 2016), it was concluded as a practical assumption that LTE-based numerology with 15 kHz subcarrier spacing is the baseline design for NR numerology. For the scale factor N, it was concluded that N=2 ⁿ (where n is an integer such as 0, 1, 2, −1, −2, . . . ) as a baseline design assumption. Correspondingly, subcarrier spacings of 15 kHz, 30 kHz and 60 kHz are being considered.

FIG. 1 shows three different subcarrier spacing settings (15 kHz, 30 kHz, and 60 kHz) and corresponding symbol periods. The symbol period Tu and the subcarrier spacing Δf are directly related by the equation Δf=1/Tu. Similar to LTE systems, the term "resource element" may be used to denote the smallest resource unit consisting of one subcarrier over the length of one OFDM symbol or single-carrier (SC) frequency division multiple access (SC-FDMA) symbol (used in the LTE uplink and possibly also in the uplink NR) symbol.

In order to support multiplexing of different services with diverse requirements, it was agreed at the 3GPP RAN1#85 meeting that NR supports multiplexing of different numerologies within the same NR carrier bandwidth (from a network perspective). On the other hand, from the UE's point of view, the UE may support one or more usage scenarios (eg, an eMBB UE or a UE supports both eMBB and URLLC). However, supporting multiple numerologies may complicate UE processing.

It is also recognized that NR should support flexible network and user equipment (UE) channel bandwidths for several reasons. First, NR is expected to support operation over a very wide range of spectrum, from sub-GHz to tens of GHz, with a variety of configurations that are very different in terms of available spectrum and thus also in terms of possible transmission bandwidths. Second, many frequency bands used for NR have not yet been fully identified, suggesting that the size of the spectrum allocation is still unknown. Third, NR is expected to support a wide range of applications and use cases, some of which require very wide UE transmit/receive bandwidth, and others require very low UE complexity, which means much lower UE transmit/receive bandwidth. Therefore, at the 3GPP RAN#85 meeting, it was agreed that the NR physical layer design should be such that devices with different bandwidth capabilities could efficiently access the same NR carrier regardless of the NR carrier bandwidth.

3GPP TR 38.913 Study on Scenarios and Requirements for Next Generation Access Technologies

One non-limiting exemplary embodiment facilitates providing an efficient set of control resources for a system using complex neurology.

In one general aspect, the technology disclosed herein comprises: a receiver capable of receiving control signals from a base station on a first set of control resources and a second set of control resources; a transmitter capable of transmitting control signals and data; in operation, controlling the transmitter to transmit a random access message associated with the first set of control resources and to transmit a communication device capability indication; and controlling a receiver to receive a configuration of a second set of control resources within the first set of control resources, and controlling the receiver to monitor the control resources in the first set of control resources and/or the second set of control resources after receiving the configuration of the second set of control resources.

The general or specific embodiments may be implemented as systems, methods, integrated circuits, computer programs, storage media, or any selective combination thereof.

Additional benefits and advantages of the disclosed embodiments will be apparent from the specification and drawings. While those benefits and/or advantages may be obtained individually by various embodiments and features of the specification and drawings, not all of them need be provided in order to obtain one or more of such benefits and/or advantages.

1 is a schematic diagram showing various neurology; FIG. FIG. 4 is a schematic diagram illustrating an example of the configuration of two control resource sets; FIG. 4 is a schematic diagram illustrating an example of the configuration of two control resource sets; FIG. 4 is a flow diagram illustrating an example procedure performed by a communications device to obtain first and second sets of controlled resources after power-on; FIG. 4 is a schematic diagram illustrating an exemplary configuration of a first control resource set in a time-frequency resource grid; FIG. 4 is a schematic diagram illustrating an exemplary configuration of a second set of control resources in a time-frequency resource grid; FIG. 4 is a schematic diagram illustrating an exemplary arrangement of first and second control resource sets centered on frequency; FIG. 4 is a schematic diagram illustrating an exemplary configuration of first and second control resource sets that are not centered on frequency; FIG. 4 is a schematic diagram illustrating an example of a configuration in which first and second control resource sets are separated; Fig. 3 is a schematic diagram illustrating frequency hopping of a first control resource set; Fig. 3 is a schematic diagram showing frequency hopping of a first set of control resources as well as a second set of control resources; Fig. 3 is a schematic diagram showing how different scheduling units in time are aligned with sub-frame boundaries (every 1 ms); FIG. 4 is a schematic diagram showing how control resource sets are indicated in the frequency domain; 1 is a block diagram showing configurations of a communication device and a base station; FIG. 1 is a block diagram showing the architecture of a communication system; FIG. Fig. 3 is a flow diagram illustrating a method for configuration of sets 1 and 2 in communication devices and base stations; Fig. 3 is a schematic diagram illustrating the division of radio resources into corresponding resource scheduling units according to three different numerology schemes; FIG. 4 is a sequence diagram representing an exemplary random access procedure;

A “mobile station” or “mobile node” or “user terminal” or “user equipment (UE)” or “communication device” is a physical entity within a communication network. One node may have several functional entities. A functional entity refers to a software or hardware module that implements and/or provides a given set of functions to a node or other functional entity of a network. A node may have one or more interfaces that attach the node to a communication facility or medium with which the node can communicate. Similarly, a network entity may have a logical interface that attaches the functional entity to a communication facility or medium through which it may communicate with other functional entities or corresponding nodes.

The term "base station" is used herein to refer to a physical entity within a communication network. A physical entity performs a number of control tasks for communication devices, including one or more of scheduling and configuration. Base station functionality and communication device functionality may also be integrated into a single device. For example, a mobile terminal may implement the functionality of a base station for another terminal.

The term "radio resource" or "resource" as used in the claim set and this application should be interpreted broadly to refer to physical radio resources, such as physical time-frequency radio resources.

As used herein, "numerology scheme" (and other similar terms such as "OFDM numerology") should be broadly understood to refer to the manner in which physical time-frequency radio resources are handled in a mobile communication system, in particular the manner in which these resources are divided into resource scheduling units that are assigned by a scheduler (e.g., within a radio base station). Stated another way, the numerology scheme may also be viewed as defined by the parameters used to divide the physical time-frequency radio resources into resource scheduling units as described above, such as subcarrier spacing and corresponding symbol duration, TTI length, number of subcarriers and symbols per resource scheduling unit, cyclic prefix length, etc. These parameters are sometimes referred to as L1 (Layer 1) parameters as they are mainly used at the physical layer for performing uplink transmissions and for receiving downlink transmissions.

The term "resource scheduling unit" should be understood as a group of physical time-frequency radio resources, which is the smallest unit that can be allocated by the scheduler. Thus, the resource scheduling unit comprises time-frequency radio resources made up of one or more consecutive subcarriers over one or more symbol periods, according to certain features of the numerology scheme.

The term "data transmission usage scenario" or simply "usage scenario" or "use case" as used in the claim set and in this application may be interpreted broadly as a range of mobile/fixed terminal usage cases. As an example, the usage scenarios being considered for the new 5G considerations could be eMBB, mMTC or URLLC, for example, as introduced in the background section.

The term "control resource" refers to resources for carrying control information rather than user data (payload). Control information may include, but is not limited to, resource allocation for downlink, uplink or sidelink.

The present disclosure provides configuration of control resource sets in networks with complex numerology (such as OFDM numerology) and UE capabilities.

An example of a system to which the present disclosure is applicable may be NR. For example, eMBB, URLLLC and mMTC may have different OFDM numerologies. For example, URLLC can achieve low delay, eg, 0.5 ms or less, with large subcarrier spacing, such as greater than 15 kHz, and short scheduling spacing. On the other hand, eMBB can reduce control overhead with large subcarrier spacing and long scheduling interval, while latency requirements are somewhat relaxed, eg, up to 4 ms. Furthermore, it is assumed that mMTC requires small carrier spacing (eg, 15 kHz or less) for large number of connections in narrow bandwidth and wide coverage. In these, and possibly further, use cases, the control resource set configurations disclosed herein may be employed.

In order to provide efficient access NR carriers for devices with different bandwidth capabilities, regardless of the actual NR carrier bandwidth, the control channel should not span the entire system bandwidth in all use cases, as is the case for normal UEs in LTE systems. Specifically, in legacy LTE, a physical downlink control channel (PDCCH) is used by base stations (called eNBs) to transmit downlink control information (DCI) to regular UEs. DCI contains downlink scheduling assignments, uplink scheduling grants, and uplink power control information, as well as further configuration parameters. In the frequency domain, the PDCCH is mapped to resource elements spread over the entire system bandwidth. In the time domain, the number of symbols occupied by the PDCCH is indicated by the Physical Control Format Indicator Channel (PCFICH).

In general, in NR there may also be similar mechanisms for sending control information (ie, downlink control information) from the base station to the communication device. Control information may be used, among other things, to schedule resources that may be further used for control information or payload. For example, base stations transmit DCI on control resource sets that must be monitored by communication devices. Here, the term "monitoring" refers to receiving by a communication device a signal carried in a control resource set and determining whether control information is addressed to that communication device (exclusively or to a group of which the communication device is a member). Such monitoring may include performing blind detection, as in LTE. In other words, the communication device detects and decodes signals within the control resource by using the communication device's own identity. The identity may be used to scramble the CRC or otherwise. Blind detection can also be attempted with different group identities to monitor (group) common DCI. If the monitoring reveals a DCI addressed to the communication device, the communication device decodes the DCI and uses the information received therein (resource grant/allocation, etc.) to access the allocated resources signaled in the DCI. In legacy LTE, DCI may be addressed to a group of UEs. Such DCIs are called group or common DCIs. On the other hand, DCI may also be addressed to individual UEs, in which case it is called UE-specific DCI. PDCCHs carrying different DCIs for different UEs/groups are distinguished by a Radio Network Temporary Identifier (RNTI) embedded in a Cyclic Redundancy Check (CRC). For example, a UE-specific C-RNTI (cell RNTI) is used for normal unicast data transmission. After checking the CRC of the PDCCH with its C-RNTI, the UE may determine whether the PDCCH is intended for it. For (group) common DCI, other types of common RNTI are used, such as SI-RNTI, P-RNTI, RA-RNTI, and TPC-PUCCH/PUSCH-RNTI for system information, paging, random access response, and PUCCH/PUSCH uplink power control commands, respectively.

In addition to PDCCH, regular UEs in legacy LTE may be configured to monitor Enhanced PDCCH (EPDCCH) over a subset of the system bandwidth. However, the EPDCCH configuration is typically provided to the UEs via Radio Resource Control (RRC) signaling, with transmissions scheduled by the PDCCH. Therefore, UEs monitoring EPDCCH are normally able to receive PDCCH. Generally, a normal UE in LTE is required to have full system bandwidth capability to receive control information even if EPDCCH is employed.

Given that in NR, the UE bandwidth capability is usually smaller than the system bandwidth, considering that the system aims to enable very wide bandwidth operation and UEs with diverse services accommodated in the same network. As a result, control channels spanning all system bandwidths do not facilitate efficient system design, at least for common DCI. In order to facilitate more efficient system design, in this disclosure the (group) common control channel is transmitted bandwidth-limited so that all UEs (within the group) with different capabilities can decode it. Duplicate messages therefore no longer need to be sent to each individual UE with matching capabilities, but such transmission would dramatically increase the signaling overhead.

On the other hand, even if the NR UE is capable of supporting the full system bandwidth, it may not need to operate at full bandwidth capability all the time. A higher operating radio frequency (RF) bandwidth means a higher power consumption of the UE. If the control channel is transmitted using a subset of the system bandwidth, UE monitoring effort may be reduced. This enables a reduction in power consumption of the UE.

Thus, control subbands or control resource sets to be monitored by all UEs may be defined. A control resource set is a set of time-frequency radio resources in which a UE attempts to blind decode DCI (or control information in general). Control resource sets are defined on control subbands that are advantageously narrower than the system bandwidth. In this disclosure, examples of control resource set configurations are presented, which may be beneficial for NR where multiple neurology coexist in the system and UEs have diverse bandwidth capabilities. To facilitate efficient system design, it is therefore desirable to obtain at least one search space (control resource set to be monitored) from system information (e.g., via cell broadcast) or implicitly derived from initial access information. This at least one search space is then used by the UE to receive control messages that allow the UE to receive higher layer signaling (such as RRC) with the configuration of additional search spaces (control resource sets that may be monitored).

One problem with having NR carriers that support multiplexing of different numerologies is that a single configuration of control resource sets for one numerology case may not work well for another configuration. Furthermore, there is a general design objective of maintaining low signaling overhead and UE power consumption. As the number of control resource sets assigned to a UE increases, so does the amount of signaling associated with control information. This can also lead to congestion when the network is serving too many UEs and when many UEs share the same set of control resources. Furthermore, if multiple control resource sets are configured for the UE, the monitoring effort of the UE will also increase, which can lead to increased power consumption of the UE.

Furthermore, it should be considered how the configuration of control resource sets can enable frequency diversity for UEs with different bandwidth capabilities. Frequency diversity is very important to achieve reliable transmission of control information. The control resource set configuration should support frequency diversity. However, in NR carriers accommodating UEs with different (bandwidth) capabilities, a single configuration for the control resource set does not work well.

Therefore, according to an embodiment, there are two control resource sets for the UE,
A "first control resource set" (set 1) is obtained by the UE from a random access procedure,
A 'second control resource set' (set 2) is configured by the base station after obtaining an indication of UE capabilities.

Each set is associated with an RF bandwidth, set 1 implies a first RF bandwidth (BW) and a second RF BW together with set 2 is configured by the base station. The first and second RF bandwidths are the bandwidths in which any resources that can be allocated by control messages carried in corresponding first and second control resource sets are located. In other words, the first and second RF bandwidths are the operating bandwidths of the UE. Nonetheless, these RF BWs are recommended from a scheduler (eg, base station) standpoint, suggesting that DCI scheduled resources are limited within these RF BWs. A UE may set its RF operating BW according to this recommendation, but may also set it in another manner different from that recommendation, as long as DCI and corresponding data transmissions can be received.

One reason a UE is configured with multiple control resource sets is for power saving purposes. RF BWs associated with different controls may be different. In that case, the UE's operating RF bandwidth may be set judiciously. As a result, when a UE is idle or inactive, the UE may be instructed to monitor a controlled resource set (e.g., set 1) that has a smaller associated RF operating bandwidth to conserve power consumption. When the UE is not inactive, the UE may be instructed to monitor a control resource set (e.g., set 2) that has a larger associated RF operating bandwidth to allow for larger allocations and thus higher data rates.

A base station may be a gNB, which is the name currently used in 3GPP to refer to an NR base station. However, the present disclosure is not limited to NRs and, consequently, to gNBs. Any other communication system may employ the configurations disclosed herein.

The first control resource set may be a subset of the second control resource set in the frequency domain. In other words, the bandwidth of the first set of control resources is included in the bandwidth of the second set of control resources. Additionally, the first set of control resources may be a subset of the second set of control resources in the time domain. In other words, the number of symbols of the first set of control resources (OFDM) may be less than or equal to the number of symbols of the second set of control resources. Therefore, the first control resource set is still being used by the UE after configuring the second control resource set. However, the disclosure is not limited to this example. This may be advantageous in some scenarios or systems if the UE stops monitoring the first resource set after acquiring the second control resource set.

As described above, the frequency range (bandwidth) of the first control resource set may be narrower than the frequency range (bandwidth) of the second control resource set to allow UEs with different capabilities to access the first control resource set, reduce UE power consumption, etc. Specifically, the frequency range of the first control resource set may overlap or be completely contained within the bandwidth of the second control resource set.

According to an exemplary configuration, control information common to two or more UEs is carried only by overlapping portions of Set 1 and Set 2. FIG. In other words, a group common search space (CSS) is carried only on resources included in both the first control resource set and the second control resource set. In contrast, a user-specific search space (USS) may be carried by the remainder of the second control resource set. This exemplary configuration is shown in FIG. The term UE-specific/group/common "search space" denotes a subset of specific/group/common control information to be monitored by blind decoding.

Specifically, FIG. 2 illustrates an example relationship between a control resource set and the control information (DCI) type carried by it. Set 1 carries common control information to be read by all UEs, possibly group control information to be read by a specific group of UEs, and UE-specific control information addressed only to specific UEs. The part of Set 2 that does not overlap with Set 1 only carries UE-specific control information and no common/group control information. Set 1 is part of Set 2. When the UE is instructed to monitor only set 2 for UE-specific DCI, there are more resources for DCI transmission (compared to the case in FIG. 3), resulting in potentially greater diversity gain.

FIG. 3 shows another example of the relationship between control resource sets and DCI. Specifically, another exemplary configuration of sets 1 and 2 is shown. In this configuration, set 1 carries common control information, group common control information and UE-specific control information, and set 2 carries UE-specific control information but no common/group control information, similar to the configuration of FIG. Set 1 and Set 2 are disjoint (mutually exclusive) in this example. The monitoring effort is also reduced when the UE is instructed to monitor only Set 2 for UE-specific DCI.

The examples described with reference to FIGS. 2 and 3 are merely illustrative, and generally set 1 and set 2 may consist of overlapping resources. Additionally, in the above example, all common search spaces and group search spaces, including common search spaces associated with all communication devices, are carried in set 1 . However, the present disclosure is not limited to such configurations. Specifically, one or more group search spaces may also be carried in set 2 .

In LTE, the UE has two different RRC states, RRC_idle and RRC_connected.

In the idle state, the UE sleeps most of the time to save power, so no data transfer takes place. The UE wakes up periodically, eg, to receive paging messages. In the connected state there is an established RRC context, ie the parameters required for communication between the UE and the radio access network are known to both entities. The connection state is intended for data transfer to/from the terminal.

In NR, these two-state designs are expected to persist, but the need to introduce additional new states, such as the inactive state, is being discussed in order to better trade-off UE power saving and wake-up time. New state behavior is still being defined.

In general, signaling traffic during idle and inactive states is considered lower than in connected states. Thus, in some example operations, the communication device may be configured to monitor only Set 1 in the idle or inactive state, and set 2 and/or Set 1 otherwise, e.g., in the Connected state. Further, when the communication device is in the connected state, the communication device may be configured to monitor only set 1 when traffic is low (e.g., below a specified threshold) and to monitor set 2 in addition to or instead of set 1 when traffic exceeds a specified threshold. Thus, a "power save" mode may include RRC_idle, RRC_connected, or possibly new states.

FIG. 4 outlines an exemplary UE procedure for obtaining the configuration of control resource sets 1 and 2 after power up. Specifically, in step 410 a communication device (UE) is switched on.

At 420, the communication device performs synchronization tasks and reads system information. Specifically, step 420 may include operations similar to those performed by a UE after power up in an LTE system. Such operations may include detecting primary synchronization sequences (PSS) and secondary synchronization sequences and performing frame and symbol synchronization accordingly.

Additionally, after synchronization, the communications device may read system information broadcast by the base station. In LTE, system information specifically includes a master information block (MIB) and a further system information block (SIB). The master information block consists of a limited number of the most frequently transmitted parameters required to perform initial access to the cell. The detailed parameters in the MIB for NR are still under discussion, but they can be designed similarly to LTE, i.e. reused to some extent. The first SIB, eg SIB1, then comprises a list of candidates for the first set of control resources, each candidate being associated with a particular set of random access channel resources (in LTE, Physical Random Access Channel (PRACH)). The association of each candidate set with a unique set of random access channel resources provides the advantage that the base station is positioned to identify a first set of control resources over which the base station transmits control information to a particular communication device based on the random access channel resources. Additionally, each candidate may be associated with additional parameters such as numerology, operating bandwidth (first bandwidth), frequency location, and the like.

The numerology and time-frequency resources for transmitting the PSS/SSS/MIB can be defined in the standard so that all UEs can decode this information. The numerology for sending further SIBs (eg, SIB1) to be read to perform random access may be the same as the MIB, or alternatively may be dictated by the MIB. The time-frequency resources for transmitting further SIBs (eg SIB1) are known to the UE from the MIB or alternatively defined in the standard. The reason for incorporating the Set 1 configuration into a further SIB (e.g., SIB1) is to avoid significantly increasing the MIB size, but still be able to utilize Set 1 to schedule the rest of the SIBs as early as possible. However, the present disclosure is not limited to the Set 1 configurations included in SIB1. The Set 1 configurations may be broadcast by the base station as any format or structure that allows UEs to receive and decode. For example, it may be included in the MIB. Furthermore, NR may apply a different structure than the MIB/SIB hierarchy used in LTE.

The above description is based on the LTE initial access procedure. However, the synchronization and system information acquisition procedures in NR may differ from those known in LTE. In any event, after power-up, the communication device synchronizes with the base station, at least to enable reading of system information. The system information may include, for example, an indication of the resource on which the further control (system) information is conveyed and/or the numerology of the control (system) information. For example, the system information may indicate a first set of controlled resources or indicate a resource on which an indication of the first set of controlled resources is conveyed. In one exemplary implementation, the system information indicates multiple candidate controlled resource sets, one of which the communication device may select to monitor. Selection of the first control resource set from the candidate set is indicated at step 430 . The communication device may select one of the candidate sets similarly according to supported numerology and bandwidth capabilities. For example, in system information there may be different candidate sets associated with different numerologies and bandwidth capabilities and different random access channel resources. To initiate a random access procedure, a communications device transmits a preamble using uplink resources associated with a pseudorandom sequence and a selected set.

At step 440, a random access procedure is performed. A random access procedure may also be employed to inform the base station of the first control resource set selected in step 430 . Specifically, during the random access procedure, the communication device transmits random access messages using resources associated with the selected control resource set. For example, such an association may be provided by associating a particular set of control resources with respective random access signatures from which the communication device selects one for inclusion in the random access preamble.

At step 450, a radio resource control (RRC) connection is established after a successful random access procedure. In other words, a signaling bearer is established to facilitate further control information exchange between the communication device and the base station. Specifically, the base station may transmit UE-specific DCI in Set 1, including scheduling information for RRC signaling in the downlink, to configure the UE.

At step 460, the communications device notifies the base station of its capabilities. UE capabilities may include, for example, operating bandwidth capabilities and/or use cases.

After informing the base station of its capabilities, the communications device continues to monitor the first set of control resources for control information in step 470 . In response to receiving the notification of UE capabilities, the base station may transmit to the communication device a configuration of a second control resource set to be monitored within the first control resource set. For example, the gNB determines the Set 2 configuration and the second RF bandwidth, bandwidth capabilities, and network conditions via the UE numerology and signals that configuration to the UE via a DCI-scheduled RRC reconfiguration message carried in the first set of control resources.

The communications device receives the configuration of the second set of controlled resources and upon receipt begins monitoring the second set of controlled resources in step 480 . As explained above, in some examples the communication device also continues to monitor the first set of controlled resources, while in other examples only the second set of controlled resources is monitored.

FIG. 5 shows an example of a first control resource set and a first operating RF bandwidth (also referred to as first bandwidth) for a UE in a network, where Set 1 bandwidth is equal to the first UE operating RF bandwidth. Specifically, FIG. 5 shows an OFDM grid, the vertical dimension of which is given by the system bandwidth (SYS BW) that extends on either side of the center frequency of the NR carrier, and the horizontal dimension of which is given by an exemplary two-slot (of 1 ms) subframe with each slot comprising seven OFDM symbols. As explained above, set 1 is used to carry both (group) common control information and UE-specific control information before transfer of UE capabilities. Furthermore, Set 1 only has control resources located within the first bandwidth (UE1's first RF BW), which is a subset of the system bandwidth. Furthermore, as can be seen from FIG. 5, the first control resource set is only located in some OFDM symbols. Specifically, in this example, the first control resource set is located in the first two OFDM symbols of each slot. However, the present disclosure is not limited to such configurations, and in general the first control resource set may be defined over any subset of the system bandwidth and (sub)frames. In this case the symbols are OFDM symbols. However, the present disclosure is not limited to OFDM. Any other time-frequency system such as SC-FDMA can be used as well. In general, other than time-frequency radio resources may also be configured.

In other words, after decoding the initial system information (e.g., SIB1) required to perform random access, the UE selects one entry (ENTRY) from the list of first control resource set candidates and returns its center frequency (i.e., the center frequency of the UE1 receiver in FIG. 5). The UE's first RF BW may be set to the minimum requirement for this list entry, ie, the minimum bandwidth configuration associated with the selected candidate set. In other words, the entry may define the range of RB BWs to be supported, outside which the UE may be configured to apply minimum requirements.

FIG. 6 shows an example of a second control resource set and a second operating RF bandwidth for a UE in a network, where the bandwidth of set 2 is smaller than the second UE operating RF bandwidth. Specifically, FIG. 6 shows the same OFDM resource grid as shown in FIG. 5, given by the system bandwidth (SYS BW) in the frequency domain and a two-slot subframe in the time domain. A second control resource set is located within the second bandwidth. The second bandwidth (marked in the figure as the second RB BW of UE1) is a subset of the system bandwidth, ie the second bandwidth is less than or equal to the system bandwidth. In Figure 6, the second control resource set is defined only in a subset of OFDM symbols (the first three symbols in each slot) in the time domain.

As noted above, in general the second bandwidth may overlap the first bandwidth. However, the present disclosure is not limited to such configurations, and the first bandwidth and the second bandwidth need not overlap. A particular example of a first bandwidth forming part of a second bandwidth is shown in FIG. Specifically, FIG. 7 shows the same OFDM grid as FIGS. 5 and 6, but here the first bandwidth (UE1's first RF BW) is completely contained within the second bandwidth (UE1's second RF BW). In this example, both the first and second bandwidths have the same center frequency (the center frequency of the UE1 receiver). As can be seen from FIG. 7, in this example the first control resource set is also completely contained within (and overlapping with) the second control resource set.

In other words, after the UE capability transfer, the gNB is ready to configure the second set of control resources and the second bandwidth for the UE. According to FIG. 7, the first and second bandwidths of the UE are center aligned, ie the center frequency of the first bandwidth is the same as the center frequency of the second bandwidth. This alignment provides the advantage of eliminating the need for retuning when the UE switches between monitoring set 1 and set 2, resulting in a shorter transition time required between monitoring the two sets. Furthermore, the message size for configuring the second set of control resources can also be reduced as there is no need to indicate the center of the bandwidth.

FIG. 8 shows another example of Set 1 and Set 2, where Set 1 and Set 2 are non-overlapping and Set 2 contains only UE-specific DCI. A connected UE may be configured to monitor both set 1 and set 2 . Specifically, FIG. 8 shows another example in which the first bandwidth and the second bandwidth are not centered with respect to each other. In this example, the first bandwidth and the second bandwidth still completely overlap, but the first bandwidth forms part of the second bandwidth. However, the first control resource set is not a subset of the second control resource set.

FIG. 9 shows an example configuration where the first bandwidth is part of the second bandwidth. However, the first set of control resources and the second set of control resources are separate from each other and discontinuous. In other words, set 1 and set 2 are non-contiguous and set 2 contains only UE-specific DCI. A connected UE may be configured to monitor both set 1 and set 2 . This provides greater flexibility for the gNB to configure the control resource set. However, in FIG. 9 the second UE operating BW is much larger than in FIGS. 7 and 8 in order to allow for separate parts from each other and specifically to allow the UE to monitor both set 1 and set 2.

Either (or both) set 1 and set 2 in any of the examples shown above may be shared by multiple UEs.

All the examples described with reference to FIGS. 5-9 show continuous UE working BWs (first and second UE working BWs), ie the RF BW is formed by N consecutive subcarriers. For UEs with relatively high bandwidth capabilities, frequency diversity can be achieved by mapping control channels to distributed physical resource blocks (PRBs) within the frequency domain within one control resource set and still within the bandwidth supported by the UE. Using such dispersion mapping in the frequency domain improves frequency diversity. A physical resource block is a scheduling unit, each having a size of multiple subcarriers and multiple symbols.

A further improvement in frequency diversity may be achieved by frequency hopping where the control resource set and associated RF BW are composed of non-contiguous frequency portions and the UE's receive window is hopped between those portions (i.e., one portion at a time). This may result in desirable frequency diversity improvements, especially for UEs with low bandwidth capabilities, eg, mMTC UEs. For such narrowband UEs, it may otherwise be difficult to achieve frequency diversity.

An example of such hopping is shown in FIG. In this configuration, the communication device follows the hopping pattern defined for the control resource set. The term "hopping pattern" herein refers to the location of control resource set instances in a time-frequency grid. Specifically, for frequency hopping, the hopping pattern indicates changes in frequency locations of control resource set instances over time.

Between different patterns, the UE may need to perform retuning. Therefore, it may be desirable to skip one or more OFDM symbols, ie not assign these symbols to the control resource set pattern, in order to provide transition time for retuning. Specifically, FIG. 10 shows the system bandwidth (SYS BW) and hopping between two patterns and the corresponding two respective subbands. First frequency portion 1010 includes first instance 1015 of first control resource set and second frequency portion 1020 includes second instance 1025 of first control resource set. As can be seen, the first instance is separated from the second instance in the time domain by one OFDM symbol (the seventh symbol) that does not carry the first control resource set. If this pattern of first and second instances is repeated for each slot, it can be seen that there is also one null OFDM symbol between the second instance and the following repeated first instance. The term "null" means that the OFDM symbol does not carry any data (control or payload).

In this example, the timeslot length is 14 OFDM symbols. Hopping is performed between 2 instances every 7 OFDM, but the length of one instance is 6 OFDM symbols.

This disclosure is not limited to any particular number of OFDM symbols per slot or per subframe, nor is it limited to any particular number of slots per subframe. In general, hopping can occur every K symbols or any arbitrary time unit. To facilitate less complex UE implementations, it may be advantageous if the length of the control resource set instances is less than or equal to the length of K symbols.

FIG. 11 shows the relationship between set 1 and set 2 with hopping, where set 1 is a subset of set 2. FIG. In this example, set 1 and set 2 have the same hopping interval, and switching between two instances in each of two different bandwidths is performed every 7 OFDM symbols. In this example, group common message/control information (DCI) is sent in the overlapping portion of set 1 and set 2 . The first bandwidth and the second bandwidth are not centered. A hopping pattern generally specifies the change in operating bandwidth over time. The example above only shows hopping between two instances. However, the disclosure is not so limited, and longer sequences of instances in which the bandwidth is switched may be defined. For example, the hopping pattern may also be defined across multiple subframes or slots, different from the example above.

However, it is not necessary that set 1 and set 2 have the same hopping pattern. An advantage of having the same hopping pattern for the two sets is that the monitoring effort on the communication device (UE) is reduced.

As mentioned above, the control resource set configuration may contain various different parameters whose values may be optimized for different use cases, such as eMBB or URLLC. Specifically, the communication device receives system information from the base station, such as system information necessary to implement a random access procedure, which system information includes a list of entries of the first control resource set of different respective configurations.

For example, an entry may have the following parameters for the first control resource set candidate.
- Subcarrier Spacing (SCS), which defines the spacing in the frequency domain between two consecutive subcarriers;
- a set bandwidth (BW) that defines the bandwidth of the set of control resources;
- the frequency location of the control resource set defining the center frequency of the control resource set - the PRB (physical resource block) index (instead of signaling the center frequency and width, the BW of a set and its frequency location can be indicated by the PRB (physical resource block) index that makes up the set)
- First RF BW (the operating bandwidth, i.e. the bandwidth in which any resource schedulable by the control information carried by the set is located, and may be assumed to be equal to the BW of the set. In such cases no additional parameters are required. However, if the bandwidth of the set is different from the operating bandwidth, another parameter may be included)
- Physical Random Access Channel (PRACH) resources (including preamble sequence and PRACH time-frequency resources)

An exemplary list of candidate control resource sets may have, for example, the following entries:
- Entry 1: SCS = 15 kHz, configured BW = 5 MHz, configured center frequency, PRACH time-frequency resources, preamble sequence - Entry 2: SCS = 60 kHz, configured BW = 20 MHz, configured center frequency, PRACH time-frequency resources, preamble sequence

In other words, entry 1 has a carrier spacing of 15 kHz and the bandwidth of the set is 5 MHz, here assumed to be the same as the operating bandwidth (similar to the example shown in FIG. 5). The center frequency indicates the band's location within the system bandwidth. A PRACH resource may include the location of the corresponding PRACH resource in the grid and a preamble sequence that may be used with this set.

For example, entry 1 may be selected by eMBB UEs, while entry 2 may be selected by URLLLC UEs. In general, if a UE supports multiple services and/or numerologies, the UE may randomly select one of the entries that matches one of the numerologies. Alternatively, there may be a predefined default numerology based on which the UE selects entries.

As another alternative, the UE may select an entry based on its UE ID. For example, entries may be selected applying the following exemplary rules.
selected_entry_index = UE_ID mod number_of_numerologies_it_supports
where mod is the modulo operation, selected_entry_index is the selection result (specifies the index of the entry among the selectable entries in the set), and number_of_numerologies_it_supports is the number of numerologies supported by the UE with the UE_ID.

As yet another alternative, the UE may select an entry based on its channel conditions. For example, if the channel is good, choose a PRACH with low diversity, otherwise choose a PRACH resource with high diversity (high repetition level, which occupies more uplink time-frequency resources).

Selection of entries in the control resource set candidate list provides the advantage of associating the random access procedure with a particular numerology and bandwidth such that no explicit signaling between the communication device and the base station is required. Rather, by implementing the random access procedure, the base station is implicitly informed of a selected set of control resources that can be monitored by and used by the base station to transmit control information to the communication device.

The same configuration parameters for the above example of set 1 may be used for set 2 as well. However, if the entries of the second set are configured with only a subset of the parameters of the configuration of the first set and it is assumed that the remaining parameters are the same as the first set, the signaling overhead for system information can be further reduced. For example, set 2 may consist only of the second bandwidth. The remaining parameters may be considered the same as for Set 1 previously selected by the UE.

An example of a set 2 configuration parameter list might be as follows.
- a set 2 BW that defines the bandwidth of control resource set 2;
- a second RF BW (second bandwidth) that defines the frequency resource to which the scheduling grant in DCI applies;
- No PRACH resource required for set 2

In the example configuration of Set 2 above, Set 1 and Set 2 are center aligned in the frequency domain (shown in FIG. 7), so no explicit signaling is needed to indicate the location of Set 2. However, the present disclosure is not so limited and set 2 may be configurable with other parameters of set 2 bandwidth.

In some of the above examples, the first control resource set carries both (group) common DCI and UE-specific DCI. Therefore, serving too many terminals can cause congestion. In other words, it may be difficult to receive user-specific DCI when there are a large number of UEs to be provided with DCI. This can be especially problematic when multiple UEs select the same control resource. Additional selection criteria apart from numerology may be applied to reduce the likelihood of congestion.

Another example of an entry in the candidate set list could be:
- Entry 1: SCS = 15 kHz, configured BW = 5 MHz, 5 MHz <= UE capability <= 20 MHz (selection criteria), configured center frequency, preamble sequence, PRACH time-frequency resources - Entry 2: SCS = 15 kHz, configured BW = 5 MHz, 20 MHz <= UE capability <= 80 MHz (selection criteria), configured center frequency, preamble sequence, PRACH time-frequency resources - Entry 3: SCS = 60 kHz , configured BW = 20 MHz, 20 MHz <= UE capability <= 80 MHz (selection criteria), configured center frequency, preamble sequence, PRACH time-frequency resources

For example, entry 1 is characterized by an SCS of 15 kHz and the bandwidth of the set is 5 MHz, assumed here to be the same as the operating bandwidth. Further, the UE bandwidth capability is due to the UE capability bandwidth range from 5MHz to 20MHz. The rest of the parameters are the same as in the example above.

The communication device then selects a set according to both its numerology and selection criteria. For example, in the list above, both entry 1 and entry 2 have the same subcarrier spacing and bandwidth, and thus both are suitable for and targeted for the same use case, such as eMBB operation. However, they differ with respect to UE capabilities, which is an additional selection criterion here. Specifically, entry 1 is for UEs with bandwidth capabilities from 5 MHz to 20 MHz, while entry 2 is for UEs with bandwidth capabilities from 20 MHz to 80 MHz. Thus, UEs with bandwidth capabilities from 20 MHz to 80 MHz (eg, 40 MHz) may select entry 2, while UEs with bandwidth capabilities below 20 MHz (eg, 10 MHz) may select entry 1. Entry 3, for example, is suitable and targeted for the URLLLC use case.

Specifically, the communications device may set the first operating bandwidth to the minimum requirement of the UE capability for the same neurology. According to the exemplary list of entries 1-3 shown above, if a UE supporting 15 kHz SCS has a bandwidth capability of 80 MHz, entry 2 would be selected and the first RF UE operating BW may be set to 20 MHz (corresponding to the minimum requirement of the selection criteria in entry 2, in other words corresponding to the minimum value of the UE capability range parameter). The advantage of such a configuration is that the gNB (or scheduler) knows that all UEs monitoring the set of entry 2 have at least 20 MHz BW capability, so the DCI carried by this set can schedule resources matching this 20 MHz without worrying about detection failures for any UEs. On the other hand, choosing an operating BW of 20 MHz for a UE with 80 MHz capability will save power consumption of the monitor.

In the example above, entry 3 is the only entry for neurology with SCS=60 kHz. However, the disclosure is not so limited. In general, there may also be one or more additional entries with the same SCS and BW and additional selection parameters with different values.

If the set BW is less than the UE's first RF operating BW (first bandwidth):
- The control resource set can be centered inside the first bandwidth in the frequency domain, so that no signaling for the center frequency is required. The size relationship between the BW of the control resource set and the first BW may be defined or signaled in the standard.
- Alternatively, the offset between the center of the set and the center of the first bandwidth can also be incorporated as one parameter.
- Or alternatively, the UE may perform blind decoding within the first bandwidth.

Accordingly, congestion problems can be reduced by appropriately grouping communication devices according to additional selection criteria. One possible selection criterion is the UE capability range in terms of bandwidth, as mentioned in the example above. With such selection criteria, the range of UE bandwidth capabilities is implicitly known to the gNB during the random access procedure. Thus, the gNB may provide the DCI with a resource allocation in the first control resource set, but the resource allocation schedules resources that match the UE's capabilities, i.e. resources that are located within the bandwidth included in the UE capabilities (e.g., the minimum UE capability range value). The example above shows only two different UE capability ranges. However, in general there may be more than two such capability ranges that are used as selection criteria.

Entries in the candidate set list may also include additional parameters that indicate whether hopping is enabled or disabled, and possibly also the signaling of the hopping pattern. An example of such a list is shown below.

- Entry 1: SCS = 15 kHz, configured BW = 5 MHz, 5 MHz <= UE capability <= 20 MHz (selection criteria), configured center frequency, hopping = false, PRACH sequence, PRACH time-frequency resources -Entry 2: SCS = 15 kHz, configured BW = 5 MHz, 20 MHz <= UE capability <= 80 MHz (selection criteria), configured center frequency, hopping = false, PRACH sequence, PRACH time-frequency resources - Entry 3: SCS = 60 kHz, configured BW = 20 MHz, 20 MHz <= UE capability <= 80 MHz (selection criteria), configured center frequency, hopping = false, PRACH sequence, PRACH time-frequency resources - Entry 4: SCS = 15 kHz, configured BW = 180 MHz, 1.4 MHz <= UE capability <= 5 MHz (selection criteria), configured center frequency, hopping = true, hopping pattern, PRACH sequence, PRA CH time-frequency resource

Therefore, there are different hopping options for each different entry in the list. Hopping can be switched on (hopping = true value in this example) or off (hopping = false value in this example). If hopping is true, a predefined or preconfigured hopping pattern may be applied.

In the example above, entries 1 and 2 may be appropriate for the eMBB use case, while entry 3 may be appropriate for the URLLC use case. Entries 1-3 have hopping turned off. Additionally, for entry 4, which has the lowest bandwidth, hopping is turned on and an additional parameter hopping pattern is configured. The parameter hopping pattern indicates the hopping pattern. This can be done by referencing one of a number of specific patterns that can be defined in the standard or configured by system information. Entry 4 can be particularly efficient for low-bandwidth use cases, such as mMTC, as it allows providing frequency diversity even for UEs with very low BW capabilities.

Also, there can be different entries in the hopping pattern that can be specified as additional parameters.

The entry list above is merely exemplary. A list with more entries with different parameter combinations can be provided. Providing greater freedom of choice can help reduce the likelihood of congestion.

Other parameters in the basic parameters described above may also be configured for the second set of control resources in order to obtain greater flexibility for configuration.

The following first and second control resource sets may be defined for the first eMBB UE.
- Set 1: SCS = 15 kHz, set BW = 5 MHz, 5 MHz <= UE capability <= 20 MHz (selection criteria), set center frequency, hopping = false, PRACH sequence, PRACH time-frequency resources - Set 2: SCS = 15 kHz, set BW = 20 MHz, second RF BW = 20 MHz, set center frequency, hopping = false

Specifically, in this example, set 1 has a setting BW that is assumed to be the same as the first bandwidth, and set 2 allows the configuration of the set bandwidth and the second bandwidth to be separated. Additionally, set 2 may be located at a different center frequency than set 1 . However, in the above entry for set 2, the operating (second RF BW) bandwidth is still set equal to the set bandwidth.

The following first and second control resource sets may be defined for the second eMBB UE.

Set 1: SCS = 15 kHz, set BW = 5 MHz, 20 MHz <= UE capability <= 80 MHz (selection criteria), set center frequency, hopping = false, PRACH sequence, PRACH time-frequency resources Set 2: SCS = 15 kHz, set BW = 40 MHz, second RF BW = 40 MHz, set center frequency, hopping = false

Additionally, for a possible URLLLC UE, two sets may be defined as follows.
- Set 1: SCS = 60 kHz, configured BW = 20 MHz, 20 MHz <= UE capability <= 80 MHz (selection criteria), configured center frequency, hopping = false, PRACH sequence, PRACH time-frequency resources - Set 2: SCS = 60 kHz, configured BW = 40 MHz, second RF BW = 80 MHz, configured center frequency, offset between configured BW center and second BW center, hopping = false

In the above entry for set 2, the set bandwidth is narrower than the second bandwidth and the offset is defined.

For a possible mMTC UE, two sets may be defined as follows.
- Set 1: SCS = 15 kHz, set BW = 180 MHz, 1.4 MHz <= UE capability <= 5 MHz (selection criteria), hopping = true, hopping pattern, PRACH sequence, PRACH time-frequency resources - Set 2: SCS = 15 kHz, set BW = 360 kHz, second RF BW = 1.4 MHz, hopping = true, hopping pattern

Specifically, in this example, the center frequencies of Set 1 and Set 2 are not given in the configuration parameters. A default location is used in this case. For example, the control resource set is always located at the edge of the system bandwidth, such as the examples shown in FIGS.

In the above examples, the focus is on configuring control resource sets in the frequency domain. However, it may also be useful to consider the position of the control resource set in the time domain.

FIG. 12 shows an exemplary alignment of various time units within subframes. A subframe is a unit of time having a length of 1 ms in this example. However, the lms subframe length is merely an example, and the present disclosure is not limited to any particular time unit length. Subframes are further divided into slots or minislots. To support multiple numerologies, each numerology may have its own scheduling interval in terms of slot or minislot length. As can be seen from FIG. 12, scheduling intervals such as slots and minislots for different neurology are aligned within subframe boundaries. Further, FIG. 12 shows the following scheduling interval lengths.

- Two 0.5ms long slots in the subframe. This configuration corresponds to a 15 kHz SCS with 7 symbols per TTI (Scheduling Interval).
- 7 minislots in a subframe. This configuration corresponds to 15 kHz SCS and 2 symbols per TTI.
- 16 minislots within a subframe. This configuration applies to 30 kHz SCS and 2 symbols per minislot.
- 8 slots in a subframe. This configuration corresponds to 60 kHz and 7 symbols per TTI.

FIG. 17 shows an exemplary numerology scheme. Specifically, FIG. 17 is a simplified diagram of radio resource partitioning according to three different numerology schemes. The resulting resource scheduling unit is shown in each of the numerology schemes as a bold square.

The numerology scheme 1 of FIG. 17 is characterized by having a subcarrier spacing of 15 kHz (with a resulting symbol duration of 66.7 μs (see FIG. 1)), 12 subcarriers and 6 symbols per resource scheduling unit. The resulting resource scheduling unit has a frequency bandwidth of 180 kHz and a length of 0.5 ms (eg, taking exemplary cyclic prefixes of 16.7 μs each, as known from LTE systems). Correspondingly, in the frequency domain, the bandwidth of the frequency band is divided into 24 resource scheduling units, each with a bandwidth of 180 kHz. With these numerology features, numerology scheme 1 can be considered for data transmission of mMTC services. Therefore, a UE following that numerology scheme can theoretically be scheduled by the scheduler every TTI, ie every 0.5 ms.

Numerology scheme 2 is characterized by having a subcarrier spacing of (2×15kHz=)30kHz (resulting symbol duration is 33.3 μs (see FIG. 1)), 12 subcarriers and 6 symbols per resource scheduling unit. The resulting resource scheduling unit thus has a frequency bandwidth of 360 kHz and a length of 0.25 ms (if we consider exemplary scaled cyclic prefixes of 16.7 μs every two). Correspondingly, in the frequency domain, the bandwidth of the frequency band is divided into 12 resource scheduling units, each with a bandwidth of 360 kHz. With these numerology features, numerology scheme 2 can be considered for data transmission of eMBB services. A UE that follows the numerology scheme can therefore theoretically be scheduled by the scheduler every TTI, ie every 0.25 ms.

Numerology scheme 3 is characterized by having a subcarrier spacing of (4×15kHz=)60kHz (resulting symbol duration is 16.7 μs (see FIG. 1)), 12 subcarriers and 4 symbols per resource scheduling unit. The resulting resource scheduling unit thus has a frequency bandwidth of 720 kHz and a length of 0.0833 ms (if we exemplarily consider every four scaled cyclic prefixes of 16.7 μs). Correspondingly, in the frequency domain, the bandwidth of the frequency band is divided into 6 resource scheduling units, each with a bandwidth of 720 kHz. With these numerology features, numerology scheme 3 can be considered for data transmission of URLLC services. Therefore, a UE following that numerology scheme can theoretically be scheduled by the scheduler every TTI, ie every 0.0833ms.

Different numerology schemes must coexist in a mobile network, and radio resources of different numerology schemes should be available to be allocated to user terminals as needed. There are several possibilities for different numerology within the frequency band and how to multiplex the radio resources within the frequency and/or time domain. In general, the available time-frequency radio resources of the frequency band should be divided among the different numerology schemes coexisting in the system in an appropriate manner, so as to be able to allocate radio resources for data transmission according to each numerology scheme. Correspondingly, each numerology scheme is associated with a particular set of radio resources from among the available radio resources of the frequency band, which set of radio resources can then be used by a scheduler (such as a radio base station) to be allocated according to that numerology scheme, i.e., to allocate radio resources for transmitting data for the corresponding service (here, URLLC, mMTC, mMBB) according to the numerology characteristics of the particular numerology scheme. This multiplexing of different coexisting numerology schemes for a service can also be flexible given the varying traffic volume of each service over time.

The communications device then monitors the control resource at most every scheduling interval. To reduce monitoring effort, greater power savings can be obtained as monitoring occurs less frequently.

In which slots/minislots DCI is expected in one subframe, the UE can be configured with RRC or more generally with higher layer protocols. Its configuration may depend on the DCI type (eg, RA-RNTI, SI-RNTI, UE-specific DCI, etc.). For example, a first slot within a subframe may be configured to carry common control information, while a second slot within the same subframe may be configured to carry UE-specific control information and no common control information. Additionally, the slot carrying group information may be designated separately from the first and second slots or may be the same. Such subdivision also allows for reduced monitoring effort, as attempts to decode control information with a particular type of RNTI (or RNTI) may be made on only one slot.

The sizes in the time domain of the first control resource set and the second control resource set may be implicitly determined by the communication device based on another configurable parameter, or configured by the base station through explicit signaling. Specifically, the number of symbols of the control resource set within the scheduling interval may be a fixed value according to the slot/minislot length. In other words, the communication device determines the number of symbols for the control resource set based on the slot size (or scheduling interval size). The determination scheme may be given in the standard, for example, as a table of the number of symbols of the control resource set for a particular configurable slot size and/or scheduling interval size.

Alternatively, the size of the resource control set is configurable. Specifically, the size of the (first or second) resource control set may be signaled in the first symbol of the (first and second respectively) resource control set, ie in the physical control format indicator channel (PCFICH). However, the present disclosure is not limited to such signaling. Alternatively, the size of the resource control sets in the time domain may be a parameter of each resource control set, selected by the communication device, and dictated by a random procedure as indicated above with respect to numerology and/or operating bandwidth range.

Additionally, the configurability of the size of the resource control set in the time domain can be configurable. For example, the parameter “PCFICH Configuration Possibilities” may be included among the configuration parameters for Set 1 and Set 2 . If the value of the parameter "Possibility of PCFICH configuration" is false, fixed values are used for the number of symbols in set 1 and/or set 2, respectively. This fixed value is either a default value or a value determined by the communication device as described above. On the other hand, if the value of the parameter "Possibility of PCFICH configuration" is true, the number of symbols is signaled by the PCFICH located within the first symbol of the control set.

A communication device may utilize different control resource sets in various manners. For example, according to the first option (option 1), different sets are configured for different neurology. The UE should perform blind decoding in all configured control resource sets. Specifically, the base station may control the communication device to monitor one or more configured control resource sets, such as a first control resource set and a second control resource set and/or another control resource set such as a third, fourth, etc. For example, there may be a set of control resources transmitted based on a numerology similar to that of resources scheduled by control information (DCI) carried in that set. Nevertheless, the monitoring effort increases with each new set monitored.

To further reduce the monitoring effort, according to option 2, one set is configured to carry DCI for data transmission of other numerology schemes. In other words, the numerology of a control resource set may differ from the numerology of resources scheduled by the control resources of that control resource set. One of the advantages of this approach is that the UE only needs to monitor one numerology scheme for control information. Control information (DCI) may then similarly indicate the neurology used by the data transmissions assigned (scheduled) by that DCI.

The frequency resources and associated RF BWs of the control resource set may be indexed by their absolute values or by indices assigned to particular values, eg in standards. Alternatively, in order to provide sufficient flexibility in signaling and at the same time conserve signaling resources, the frequency resources of the (first and/or second) control resource set may be directed relative to the resource grid in the same numerology scheme that the set targets.

For example, the resource grid is defined per numerology scheme and known to both the gNB and the UE. The grid does not change with respect to resource allocation. This state is shown in FIG. Specifically, FIG. 13 shows three respective grids as three rows for three different neuronologies with subcarrier spacings of 60 kHz, 30 kHz and 15 kHz. UE1 in FIG. 13 may be informed of the first RF BW as {RB#-13 to RB#-10} by SCS at 15 kHz. In other words, the first bandwidth and/or the second bandwidth may be indicated by the lowest resource block (RB) index and the highest resource block index belonging to the respective bandwidth. A resource block may be the smallest allocatable unit in the frequency domain and may include several subcarriers, eg, 12 subcarriers.

Thus, control information (eg, dedicated RRC signaling or higher layer signaling such as broadcasted system information, and physical layer signaling) carrying control resource sets can be signaled with improved efficiency.

However, the present disclosure is not limited to such signaling. In general, the operating bandwidth can be signaled by its center frequency and width, or in any other manner such as lowest RB and bandwidth.

Additionally, the signaling described above may be used to indicate any subband of the system band by lowest and highest frequency (indicated by resource block index). In other words, this signaling scheme is not limited to signaling an operating bandwidth, but can be used to indicate any frequency band or range (e.g., the capability bandwidth range described above in connection with candidate set configuration).

The present disclosure can be implemented in software, hardware, or software cooperating with hardware. Each functional block used in the description of each embodiment described above can be partially or wholly realized by an LSI such as an integrated circuit, and each process described in each embodiment can be partially or completely controlled by the same LSI or a combination of LSIs. The LSI may be formed individually as chips, or may be formed so that one chip includes some or all of the functional blocks. An LSI may include a data input and a data output coupled to it. The LSI here can be called an IC, system LSI, super LSI, or ultra LSI depending on the degree of integration. However, the technology for implementing integrated circuits is not limited to LSIs, and may be implemented by using dedicated circuits or general-purpose or special-purpose processors. In addition, an FPGA (Field Programmable Gate Array) that can be programmed after the LSI is manufactured or a reconfigurable processor that can reconfigure the connections and settings of circuit cells arranged inside the LSI may be used. The present disclosure may be implemented as digital or analog processing. If future integrated circuit technology replaces LSI as a result of advances in semiconductor technology or other derivative technologies, the functional blocks can be integrated using that future integrated circuit technology. Biotechnology may also be applied.

FIG. 14 shows a block diagram of a system including a communication device 1410 and a scheduling device 1460 communicating with each other via a (wireless) physical channel 1450 . Communication device 1410 comprises transceiver 1420 and circuitry 1430 . Transceiver 1420 comprises a receiver and a transmitter. Circuitry 1430 may be one or more pieces of hardware, such as one or more processors or any of the LSIs described above. Between the transceiver 1420 and the circuit 1430 there is an input/output point 1425 via which the circuit controls the transceiver 1420 in operation, i.e. controls the receiver and/or transmitter and exchanges received/transmitted data. Transceiver 1420 may include an RF front including one or more antennas, amplifiers, RF modulators/demodulators, and the like. Circuit 1430 may specifically implement control tasks such as controlling transceiver 1420 to transmit user data, control data provided by the circuit, and/or receive user and control data to be further processed by the circuit.

A simple exemplary scenario is shown in FIG. 15 with a radio base station and several user terminals. Each of the three UEs shown supports different services, namely mMTC, eMBB and URLLC services already introduced in the background section. As shown, one UE shall support and be configured for two different services, typically URLLC and eMBB services.

A radio base station in FIG. 15 may correspond to base station 1460 in FIG. Any of the three UEs in FIG. 15 may correspond to communication device 1410 in FIG.

According to one embodiment, a communications device 1410 is provided and comprises a receiver 1420 capable of receiving control signals from a base station 1460 on a first set of control resources and a second set of control resources. Communication device 1410 further comprises a transmitter 1420 capable of transmitting control signals and data, and circuitry 1430 which, in operation,
- controlling a transmitter to transmit a random access message associated with a first set of control resources and to transmit a communication device capability indication;
- controlling the receiver to monitor controlled resources in the first set of controlled resources after sending the random access message and to receive within the first set of controlled resources an indication of the configuration of the second set of controlled resources;
- controlling the receiver to monitor the control resources in the first set of control resources and/or the second set of control resources after receiving the configuration of the second set of control resources;

The indication of the configuration of the second set of control resources may be, for example, a resource allocation of higher layer signaling conveying the configuration of the second set of control resources for the communication device. However, the disclosure is not limited to this example. For example, the indication may also refer directly to the second set of controlled resources.

A first set of control resources is located within a first bandwidth and a second set of control resources is located within a second bandwidth. Here, the first bandwidth is the bandwidth in which any resource allocated by the control information conveyed in the first set of control resources is located, and the second bandwidth is the bandwidth in which any resource allocated by the control information conveyed in the second set of control resources is located.

The first bandwidth and the second bandwidth may be the same. In other words, allocations received in the first resource set may span the same operating bandwidth as allocations received in the second resource set. However, if the first bandwidth is a subset of the second bandwidth, monitoring effort and power consumption may be reduced.

In one example, the first bandwidth and the second bandwidth are centered on each other in the frequency domain. Similarly, the bandwidths of each of the first and second control resource sets may also be centered with respect to each other.

Regarding the relationship between the two sets, in one example, the bandwidth of the first set of control resources is included in the bandwidth of the second set of control resources. Furthermore, the first set of control resources may be a subset of the second set of control resources. For example, if the resources are defined in a time-frequency grid of number of symbols in time and number of subcarriers in frequency, in addition the symbols carrying the first set of control resources may be included in the symbols carrying the second set. However, the present disclosure is not limited by the relationship between Set 1 and Set 2 in the time domain.

According to another example, the first set of control resources and the second set of control resources are separate from each other in the frequency domain or only partially overlap.

The bandwidth of the first control resource set is equal to or less than the first bandwidth. Similarly, the bandwidth of the second control resource set is equal to or less than the second bandwidth.

In any of the above examples, the first set of control resources advantageously includes common control information for decoding by multiple communication devices, as well as user-specific control information for decoding only by specific communication devices, and the second set of control resources includes user-specific control information.

The second set of control resources may also contain (group) common control information, which is especially true when set 1 is a subset of set 2 . On the other hand, if set 1 and set 2 are separate (or partially overlapping), set 2 need not contain any (group) common control information.

The circuitry, in operation, may control the receiver to monitor the first set of control resources when the communications device is in an operational mode that facilitates power saving.

Modes that promote power savings may, for example, be modes in which the communication device has no active data connections or only low activity (eg, below a certain traffic threshold) data connections. For example, the mode promoting power saving may correspond to the idle mode defined in LTE (no data bearers established).

Additionally, the circuitry, in operation, may control the receiver to monitor the second set of control resources when the communications device is not in an operational mode that facilitates power savings. In addition to monitoring the second set, the receiver can also be controlled to still monitor the first set.

Alternatively, the circuit may be configured, in operation, to control the receiver to monitor the first set of control resources when the communication device traffic does not exceed the threshold and to monitor the second set of control resources when the communication device traffic exceeds the threshold. The threshold may be configured by the base station and provided to the communication device via higher layer signaling. Alternatively, it may be specified by the standard. Alternatively, the threshold may be used only by the base station, which directs communication according to the threshold whether the first control resource set or the second control resource set is to be monitored.

To further improve frequency diversity, the first control resource set is distributed in the frequency domain, and the circuit, in operation, controls the receiver to perform frequency hopping every first predetermined time interval to monitor the first control resource set.

In one example, the second control resource set is distributed in the frequency domain, the circuitry, in operation, controls the receiver to perform frequency hopping every second predetermined time interval to monitor the second control resource set, and the hopping pattern of the first control resource set is similar to the hopping pattern of the second resource set.

The first and second predetermined time intervals may be a specific number K such as symbols or slots or subframes. They can be the same or different from each other. Frequency hopping may generally be applied only to the first set, only to the second set, applied to neither of the sets, or applied to both.

In one example, the second control resource set is distributed in the frequency domain, and the circuitry, in operation, controls the receiver to perform frequency hopping every second predetermined time interval to monitor the second control resource set, and the hopping pattern of the first control resource set differs from the hopping pattern of the second resource set in at least one frequency band in at least one time interval.

The hopping pattern of the first set of control resources defines a sequence of the first set of bandwidths (and corresponding operating bandwidths) that change over time. The pattern can be applied repeatedly and periodically.

According to an exemplary combination of the above examples, the circuitry is further configured to control the receiver to receive system information including a list of entries, the entries representing respective candidates for the first controlled resource set configuration, and to control the receiver to select the first controlled resource set configuration.

The selection can be performed, for example, based on the supported numerology.

Specifically, the first control resource set configuration parameters include at least one of subcarrier spacing and bandwidth of the first control resource set, and at least one of preamble sequence and random access channel resources.

In one example, the circuitry, in operation, selects the first control resource set according to at least one of subcarrier spacing and a bandwidth of the first control resource set supported by the communication device.

The second control resource set configuration may also be given by a second control resource set configuration parameter comprising at least the bandwidth of the second control resource set or the second bandwidth (the operating bandwidth for receiving data scheduled by the control information carried in the second set). However, the second control resource set configuration parameter may also include numerology.

In one example, the first controlled resource set configuration parameter further includes a range of bandwidth capabilities of the communication device, and the circuit, in operation, selects the first controlled resource set according to its bandwidth capabilities as well.

Further, the circuit, in operation, selects a first controlled resource set configuration if the communications device supports multiple configurations by:
- a random selection of one of the supported configurations,
- selecting a configuration with default subcarrier spacing and/or bandwidth of the first control resource set;
- selection based on the identifier of the communication device;
- Can be implemented as any of the selections based on the current channel conditions of the communication device.

The first control resource set configuration parameter and/or the second control resource set configuration parameter may also further include a hopping indication indicating whether frequency hopping should be applied to the corresponding control resource set.

Additionally, the first control resource set configuration parameter and/or the second control resource set configuration parameter may further include a hopping pattern indication if the hopping indication indicates that hopping should be applied to the corresponding control resource set.

A hopping pattern describes the sequence in time of frequencies (bandwidths) that carry the control resource set.

The configuration of the second control resource set may include either the bandwidth of the second control resource set or the second bandwidth, or a subset of the configuration parameters, and the circuit, in operation, applies the remaining parameters of the first control resource set to the second control resource set.

In one exemplary embodiment, the circuit, in operation,
- to monitor the first set of controlled resources and/or the second set of controlled resources, and
- controlling the receiver to receive control information indicating resource allocation for data transmission to the communication device within the first control resource set and/or the second control resource set;
- Resource allocation also indicates a time-frequency numerology including at least one of subcarrier spacing, bandwidth, number of symbols or cyclic prefix length.

The present disclosure also relates to scheduling a node 1460 comprising a transmitter 1470 capable of transmitting a control signal to a communication device on a first set of control resources and a second set of control resources, a receiver 1470 capable of receiving the control signal and data, and a circuit 1480, the circuit 1480, in operation:
- controlling a receiver to receive a random access message associated with a first set of control resources and to receive a communication device capability indication;
- controlling the transmitter to transmit control information on the first set of control resources after receiving the random access message and to transmit within the first set of control resources an indication of the configuration of the second set of control resources;
- controlling the transmitter to transmit control information on the first set of control resources and/or the second set of control resources after transmitting the configuration of the second set of control resources;

As can be seen in FIG. 14, there is also an input/output node 1475 located between the transceiver 1470, which includes the transmitter and receiver, and the circuit 1480. FIG. Input/output node 1475 services the input/output of data and control commands between transceiver 1470 and circuitry 1480 . Scheduling node 1460 may be, for example, a base station. However, the disclosure is not so limited and the scheduling node may be a relay node or a communication device operating as a base station or relay node for other communication devices.

As can also be seen from FIG. 14, both the communication device and the base station use the same configuration of set 1 and set 2 and exchange configuration information as already explained above in relation to the communication device. Accordingly, the embodiments and examples described above focusing on communication devices also apply to scheduling nodes (base stations).

The present disclosure also provides corresponding methods that may be implemented by circuitry 1430 of communication device 1410 and/or circuitry 1480 of base station 1460 . Specifically, those circuits may control the communication device and the corresponding receiver/transmitter of the base station to perform the receive/transmit tasks as described below.

Specifically, as also shown in FIG. 16, a method for a communication device comprising:
- sending 1620 a random access message associated with the first set of control resources;
- monitoring 1630 the control resources in the first set of control resources after sending the random access message;
- sending 1640 a communication device capability indication;
- after step 1640 of sending a communication device capability indication, receiving 1650 an indication of the configuration of the second set of controlled resources within the first set of controlled resources;
- monitoring 1660 the control resources in the first set of control resources and/or the second set of control resources after receiving the configuration of the second set of control resources.

Further, the method may also include step 1610 of receiving control information including the configuration of the candidate first control resource set prior to sending the random access message. This control information may be received within a system broadcast.

Further, a method for a scheduling node, comprising:
- receiving 1625 a random access message associated with the first set of control resources;
- a step 1645 of receiving a communication device capability indication (after step 1625 of receiving a random access message);
- after step 1625 of receiving the random access message, step 1635 of sending control information on the first set of control resources;
- sending 1655 an indication of the configuration of the second set of control resources within the first set of control resources;
- transmitting 1665 control information on the first set of control resources and/or the second set of control resources after transmitting the configuration of the second set of control resources.

The steps described above may be performed as disclosed above in relation to the operations performed by the respective device.

Furthermore, the above examples relate to a "communication device" or "UE" or "base station" or "gNB" or "scheduling device". However, the circuitry of each of these devices alone (see circuits 1430 and 1480 in FIG. 14) alone can already provide the improvements described above. This circuitry controls the transmitter and receiver of the device, which may be standard wireless transmitters and receivers including, for example, one or more antennas, amplifiers and modulators. The control is performed by outputting control commands to the input/output nodes (1425, 1475) and inputting received data (control and/or user data) from the input/output nodes for further processing by the circuit.

FIG. 18 shows an exemplary random access procedure.

In step 1810, a UE (communication device) sends a random access preamble (i.e., a random access message) using the sequence over the uplink time-frequency resources associated with control resource set 1 selected from the candidate set.

In step 1820, the BS (base station, scheduling device) detects a random access attempt and then sends a message over the downlink data channel, which message is:
- the index of the random access preamble sequence detected by the network and for which the response is valid;
- timing corrections calculated by the random access preamble receiver,
- a scheduling grant indicating the resources that the terminal will use for the transmission in step 1830;
- Contains the TC-RNTI, which is a temporary identity used for further communication between the UE and the network.

Since each Set 1 candidate has a separate sequence (and/or associated uplink resources for sending the preamble), the BS knows which Set 1 the UE has selected after decoding the preamble sequence. Therefore, the DCI indicating the resources carrying the above mentioned messages is sent in set 1 selected by the UE.

A UE that sent a preamble monitors the corresponding set 1 to receive the DCI and thus the message.

In step 1830, after step 1820, the UE's uplink is time synchronized to the network. In step 1830, the UE sends the identifier to the BS via normal uplink data channel and performs an RRC connection request. (There are no modifications compared to the LTE procedure)

At step 1840, contention resolution is performed. If multiple UEs happen to select the same random access resource (preamble sequence and associated uplink resource) from step 1820, those UEs performing simultaneous random access attempts using the same preamble resource in the first step 1810 will listen to the same response message in the second step 1820 and thus have the same temporary identifier. Therefore, in the fourth step 1840 each terminal receiving the downlink message will compare the identity in the message with the identity sent in the third step 1830 . Only terminals observing a match between the identity received in the fourth step 1840 and the identity transmitted as part of the third step 1830 will declare the random access procedure successful.

Step 1840 of the random access procedure exemplified above is similar to the LTE procedure, except that in step 1840 the DCI scheduling message is again transmitted in Set 1 selected by the UE. The random access procedure described with reference to Figure 18 is merely exemplary. The present disclosure is not limited by this random access procedure, and random access may also be implemented in different schemes. In general, any access with randomly selected resources (by the random access message sender) may be applied.

Claims (9)

An integrated circuit for controlling processing of a scheduling node, the scheduling node comprising:
a transmitter capable of transmitting control signals to a communication device on a first set of control resources and a second set of control resources;
a receiver capable of receiving control signals and data;
The processing is
controlling the receiver to receive a random access message associated with the first set of controlled resources and to receive a communication device capability indication;
controlling the transmitter to transmit control information on the first control resource set after receiving the random access message and to transmit an indication of configuration of a second control resource set in the first control resource set;
controlling the transmitter to transmit control information on the first control resource set and/or the second control resource set after transmitting the configuration of the second control resource set;
Said processing further comprises:
controlling the transmitter to transmit, using system information, a plurality of entries, each entry indicating a respective candidate for configuration of the first control resource set;
informed of a configuration of the first control resource set selected from the plurality of entries using a random access message associated with the received first control resource set;
integrated circuit. the first control resource set located within a first bandwidth and the second control resource set located within a second bandwidth;
the first bandwidth is the bandwidth in which any resources allocated by control information carried in the first set of control resources are located;
the second bandwidth is the bandwidth in which any resources allocated by control information carried in the second control resource set of control resources are located;
The integrated circuit of Claim 1. wherein the first bandwidth and the second bandwidth are centered on each other in the frequency domain;
3. The integrated circuit of claim 2. The bandwidth of the first control resource set is included in the bandwidth of the second control resource set;
the first control resource set is a subset of the second control resource set;
4. An integrated circuit according to claim 2 or 3. the first control resource set includes common control information decoded by multiple communication devices and user-specific control information decoded only by a specific communication device;
the second set of control resources includes the user-specific control information;
The integrated circuit of Claim 1. the configuration parameters of the first control resource set and/or the configuration parameters of the second control resource set include at least one of a subcarrier spacing and a corresponding bandwidth of the control resource set, and at least one of a preamble sequence and a resource of a random access channel of the first control resource set;
The integrated circuit of Claim 1. configuration parameters of the first set of control resources further comprising a range of bandwidth capabilities of the communication device;
7. An integrated circuit as claimed in claim 6. the first control resource set configuration parameter and/or the second control resource set configuration parameter further includes a hopping indication specifying whether frequency hopping should be applied to the corresponding control resource set;
7. An integrated circuit as claimed in claim 6. the first control resource set configuration parameter and/or the second control resource set configuration parameter further comprises a hopping pattern indication when the hopping indication indicates that hopping should be applied to the respective control resource set;
9. The integrated circuit of claim 8.

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