CN111919472A

CN111919472A - Random access response for BWP

Info

Publication number: CN111919472A
Application number: CN201880091405.7A
Authority: CN
Inventors: 吴春丽; S·图尔蒂南; D·科齐欧; K·肖伯
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Networks Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Oyj
Priority date: 2018-04-12
Filing date: 2018-04-12
Publication date: 2020-11-10
Anticipated expiration: 2038-04-12
Also published as: WO2019196066A1; CN111919472B

Abstract

The method includes receiving, at a user terminal, a configuration of at least one common search space identifier for a corresponding physical random access channel on at least one uplink bandwidth portion. The method also includes determining whether at least one transmission is received on the associated at least one common search space identifier for at least one active downlink bandwidth portion. The method also includes determining whether to switch the downlink bandwidth part after initiating a random access procedure based on whether the user terminal received a transmission on the associated at least one common search space identifier for the at least one active downlink bandwidth part.

Description

Random access response for BWP

Technical Field

The teachings in accordance with the exemplary embodiments of this invention relate generally to radio standards and, more particularly, relate to downlink control channel transmission and reception.

Background

In the conference of 3GPP RAN2, an agreement has been reached for random access to be supported on different BWPs. It is also agreed that a common search space can be configured on any DL BWP to send a Random Access Channel (RACH) response (RAR).

To avoid sending multiple RARs from multiple DL BWPs, the RAN2 conference determines the following working assumptions. For Frequency Division Duplex (FDD) and contention-based random access (CBRA), PRACH configurations/resources are linked (implicitly or explicitly) with DL BWP. The UE monitors only RARs on DL BWPs linked to the used PRACH resources. UL BWP with BWP index k is linked with DL BWP k (e.g., with the same BWP index). If the UE intends to transmit a preamble on UL BWP k, the active DL BWP must be DL BWP k.

Certain abbreviations that may be found in the specification and/or in the drawings are defined as follows:

BWP bandwidth portion

CA carrier aggregation

CC component carrier

CE control element

CORESET control resource aggregation

CSS Common search space

DAI downlink assignment index

DCI downlink control information

gNB 5G enhanced node B (base station)

LTE Long term evolution

MEC multi-access edge computation

MME mobility management entity

NCE network control element

NR new radio

NR-PDCCH new radio physical downlink control channel network

PBCH physical broadcast channel

PDCCH physical downlink control channel

PDSCH physical downlink shared channel

Physical Random Access Channel (PRACH)

RE resource unit

RF radio frequency

RRC radio resource control

RS reference signal

SS search space

TRP transmission-reception point

TXRU transceiver unit

UE user equipment

UL uplink

5G fifth generation mobile communication system

Disclosure of Invention

The following summary includes examples and is intended to be exemplary only. This summary is not intended to limit the scope of the claims:

according to one aspect, an example method includes: at a user terminal, a configuration of at least one common search space identifier is received, the at least one common search space identifier being for a corresponding physical random access channel on at least one uplink bandwidth portion. The method also includes determining whether at least one transmission is received on the associated at least one common search space identifier for at least one active downlink bandwidth portion. The method also includes determining whether the downlink bandwidth part is being handed over after initiating a random access procedure based on whether the user terminal received a transmission on the associated at least one common search space identifier for the at least one active downlink bandwidth part.

According to another aspect, an exemplary apparatus comprises at least one processor; at least one non-transitory memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to: receiving a configuration of at least one common search space identifier for a corresponding physical random access channel on at least one uplink bandwidth portion; determining whether at least one transmission is received on the associated at least one common search space identifier for at least one active downlink bandwidth portion; and determining whether to switch the downlink bandwidth part after initiating a random access procedure based on whether the user terminal received a transmission on the associated at least one common search space identifier for the at least one active downlink bandwidth part.

According to another aspect, an example apparatus includes: means for receiving a configuration of at least one common search space identifier for a corresponding physical random access channel on at least one uplink bandwidth portion; means for determining whether at least one transmission is received on the associated at least one common search space identifier for at least one active downlink bandwidth portion; and means for determining whether to switch the downlink bandwidth part based on whether the user terminal received a transmission on the associated at least one common search space identifier for the at least one active downlink bandwidth part.

Drawings

The foregoing and other aspects of embodiments of this invention will become more apparent in the following detailed description when read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a block diagram of one possible and non-limiting example system in which example embodiments may be practiced;

FIG. 2 shows an example illustration of different configurations of multiple BWPs;

fig. 3 shows an example table of supported PDCCH mapping options;

fig. 4 shows a method according to an example embodiment that may be performed by an apparatus.

Detailed Description

In example embodiments described herein, methods and apparatus to provide random access response for a bandwidth segment.

Turning to FIG. 1, a block diagram of one possible and non-limiting example system is shown in which example embodiments may be practiced. In fig. 1, a User Equipment (UE)110 is in wireless communication with a wireless network 100. A UE is a wireless, typically mobile device that may access a wireless network. UE110 includes one or more processors 120, one or more memories 125, and one or more transceivers 130 interconnected by one or more buses 127. Each of the one or more transceivers 130 includes a receiver Rx 132 and a transmitter Tx 133. The one or more buses 127 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of wires on a motherboard or integrated circuit, an optical fiber, or other optical communication device, and so forth. One or more transceivers 130 are connected to one or more antennas 128. The one or more memories 125 include computer program code 123. UE110 includes a signaling module 140 that includes one or both of portions 140-1 and/or 140-2, which may be implemented in a variety of ways. The signaling module 140 may be implemented in hardware as a signaling module 140-1, such as part of one or more processors 120. The signaling module 140-1 may also be implemented as an integrated circuit or by other hardware, such as a programmable gate array. In another example, the signaling module 140 may be implemented as a signaling module 140-2 that is implemented as computer program code 123 and executed by one or more processors 120. For example, the one or more memories 125 and the computer program code 123 may be configured to, with the one or more processors 120, cause the user equipment 110 to perform one or more operations as described herein. UE110 communicates with eNB 170 via wireless link 111.

The gNB (NR/5G node B, but possibly an evolved NodeB)170 is a base station (e.g., for LTE, long term evolution, or for NR new radio) that provides access to a wireless network by wireless devices, such as UE 110. The gNB 170 includes one or more processors 152, one or more memories 155, one or more network interfaces ((N/WI/F) 161, and one or more transceivers 160 interconnected by one or more buses 157. Each of the one or more transceivers 160 includes a receiver Rx162 and a transmitter Tx 163. One or more transceivers 160 are connected to one or more antennas 158. The one or more memories 155 include computer program code 153. The gNB 170 includes a reporting module 150, the reporting module 150 including one or both of the portions 150-1 and/or 150-2, which may be implemented in a variety of ways. The reporting module 150 may be implemented in hardware as a reporting module 150-1, such as part of one or more processors 152. The reporting module 150-1 may also be implemented as an integrated circuit or by hardware, such as a programmable gate array. In another example, the reporting module 150 may be implemented as a reporting module 150-2, which is implemented as computer program code 153 and executed by one or more processors 152. For example, the one or more memories 155 and the computer program code 153 are configured, with the one or more processors 152, to cause the gNB 170 to perform one or more operations described herein. One or more network interfaces 161 communicate over a network, such as via

links

176 and 131. Two or more gnbs 170 communicate using, for example, link 176. The link 176 may be wired or wireless, or both, and may implement, for example, an X2 interface.

The one or more buses 157 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of wires on a motherboard or integrated circuit, an optical fiber or other optical communication device, a wireless channel, and so forth. For example, one or more transceivers 160 may be implemented as Remote Radio Heads (RRHs) 195, wherein other elements of the gNB 170 are physically located at a different location than the RRHs, and one or more buses 157 may be implemented in part as optical fibers to connect the other elements of the gNB 170 to the RRHs 195.

Note that the description herein indicates that "cell" performs the function, but it should be clear that the gnbs forming the cell will perform the function. The cell forms part of the gbb. That is, there may be multiple cells per gbb. Each cell may contain one or more Transmission and Reception Points (TRPs).

The wireless network 100 may include a Network Control Element (NCE)190, and the NCE 190 may include MME (mobility management entity)/SGW (serving gateway) functionality and provide connectivity to additional networks, such as a telephone network and/or a data communications network (e.g., the Internet). The gNB 170 is coupled to the NCE 190 via link 131. Link 131 may be implemented as, for example, an S1 interface. NCE 190 includes one or more processors 175, one or more memories 171, and one or more network interfaces ((N/WI/F) 180 interconnected by one or more buses 185. The one or more memories 171 include computer program code 173. The one or more memories 171 and the computer program code 173 are configured to, with the one or more processors 175, cause the NCE 190 to perform one or more operations.

Wireless network 100 may implement network virtualization, which is the process of combining hardware and software network resources and network functions into a single, software-based management entity, i.e., a virtual network. Network virtualization involves platform virtualization, often combined with resource virtualization. Network virtualization is classified as either external (combining many networks or parts of networks into one virtual unit) or internal (providing network-like functionality to software containers on a single system). It should be noted that the virtualized entities resulting from network virtualization are still implemented to some extent using hardware, such as the

processor

152 or 175 and the

memories

155 and 171, and that such virtualized entities also produce technical effects.

The computer-

readable memories

125, 155 and 171 may be of any type suitable to the local technical environment, and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The computer

readable memories

125, 155 and 171 may be means for performing a storage function.

Processors

120, 152, and 175 may be of any type suitable to the local technical environment, and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, Digital Signal Processors (DSPs) and processors based on a multi-core processor architecture.

Processors

120, 152, and 175 may be means for performing the functions of controlling gNB 170 of UE110, as well as other functions described herein.

In general, the various embodiments of the user device 110 can include, but are not limited to, cellular telephones (such as smart phones), tablet computers, Personal Digital Assistants (PDAs) having wireless communication capabilities, portable computers having wireless communication capabilities, image capture devices (such as digital cameras having wireless communication capabilities), gaming devices having wireless communication capabilities, music storage and playback appliances having wireless communication capabilities, internet appliances permitting wireless internet access and browsing, tablet computers having wireless communication capabilities, and portable units or terminals that incorporate combinations of such functions.

Embodiments herein may be implemented in software (executed by one or more processors), hardware (e.g., application specific integrated circuits), or a combination of software and hardware. In an example of an embodiment, software (e.g., application logic, a set of instructions) is maintained on any of a variety of conventional computer-readable media. In the context of this document, a "computer-readable medium" may be any media or means that can contain, store, communicate, propagate or transport the instructions for use by an instruction execution system, apparatus, or device, such as a computer, for example, one example of a computer described and depicted in FIG. 1. A computer-readable medium may include a computer-readable storage medium or other device that may be any medium or means that can contain or store the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer.

The current architecture in LTE networks is fully distributed in the radio and fully centralized in the core network. The low latency requirement is to bring the content close to the radio, which results in local breakout and multiple access edge computation (MEC). 5G may use edge cloud and local cloud architectures. Edge computing covers a wide range of technologies such as wireless sensor networks, mobile data acquisition, mobile signature analysis, collaborative distributed peer-to-peer ad hoc networks and processes, and can also be divided into local cloud/fog computing and grid/mesh computing, dew computing, mobile edge computing, clouds (cloudlet), distributed data storage and retrieval, autonomous self-healing networks, remote cloud services, and augmented reality. In radio communications, using an edge cloud may mean that node operations are to be performed at least in part in a server, host, or node operatively coupled to a remote radio head or base station that includes a radio portion. Node operations may also be distributed among multiple servers, nodes, or hosts. It should also be understood that the labor allocation between core network operation and base station operation may be different than that of LTE, or even non-existent. Some other technological advances that may be used are Software Defined Networking (SDN), big data, and all IP, which may change the way the network is built and managed.

Example embodiments may be implemented in a network backhaul. Example embodiments may also be implemented in a relay node (e.g., with respect to the functionality described herein below with respect to UE 110). Further, in a multihop relay scenario, a Radio Network (RN) (e.g., network 100) may implement the functionality described below with respect to the gNB 170.

Having thus introduced a suitable but non-limiting technical context for practicing the exemplary embodiments of this invention, the exemplary embodiments will now be described in greater detail.

Fig. 2 illustrates an example 200 of different configurations of a multi-DL BWP. Two UEs 110, such as UE 1210-1 and UE2210-2, may be configured with the same DL BWP including core set (Coreset) id 0 and SS id 0(CSS)₁。

For a single UE, the signaling structure of the PDCCH configuration for BWPs may allow the network to configure the same CORESET/search space for multiple BWPs when they overlap, e.g., UE 1210-1 in fig. 2 is configured with CSS0 for two DL BWPs 1(230-1) and DL BWP2 (235-1).

As shown in fig. 2, one user equipment UE110, such as UE 1210-1, may be configured with DL BWP with Coreset id 0 and SS id 0(CSS) (240-1)₁(230-1) byAnd DL BWP₂(235-1) (e.g., 40MHz), which may be measured along the frequency axis 220. The UE 1210-1 may also be configured with UL BWP 1250-1. Another user equipment UE110, such as UE2210-2, may be configured with DL BWP with Coreset id 0 and SS id 0(CSS) (240-2-0)₁(e.g., initial BWP is 10MHz 230-2) and DL BWP with Coreset id 1 and SS id 1(CSS) (240-2-1)₂(235-2)。

Instead of linking DL BWP k to UL BWP k, example embodiments may explicitly configure the received Common Search Space (CSS) ID for RAR and/or msg4 on DL BWP for the corresponding PRACH on UL BWP. The UE110 may decide whether to handover its DL BWP when initiating the random access procedure based on whether it can receive on an associated CSS on the active DL BWP (e.g., based on whether the CSS is associated with the active DL BWP of the UE when performing the random access). According to example embodiments, PRACH on UL BWP may be associated with CORESET/CSS and not with DL BWP of the UE to avoid unnecessary handover of DL BWP during PRACH procedure. The search space configuration contains an association with the CORESET ID, and thus UE110 knows the association between the CORESET and the user-specific and common search space within the CORESET.

In case the UE110 has to switch its active DL BWP and there are multiple DL BWPs from which the RAR is received (e.g. the same CSS ID is associated to both), the UE110 may select the DL BWP based on the following selection principle or a combination thereof. DL BWPs with lower/higher BWP indices containing configured CSS may be selected. A DL BWP with narrower/wider BW containing configured CSS may be selected. An initial DL BWP is selected on any specially configured DL BWP. The default DL BWP is selected from any other configured DL BWPs. The NW may explicitly configure which to select if the UE110 has to switch its DL BWP.

Fig. 3 illustrates one example of a sequence diagram 300 including a BWP downlink dedicated sequence 310 and a PDCCH configuration sequence 320.

IE controlresouseset may be used to configure a time/frequency control resource set (CORESET) in which to search for downlink control information. The associated ControlResourceSet information element may include instructions for configuration of CORESET. This may include a controlResourceSetId, which is unique in the BWP of the ServingCell. Each bit may correspond to a set of 6 RBs, the packet starting from PRB 0, which is completely contained in the bandwidth part within which the CORESET is configured. The most significant bits correspond to the lowest frequency group that is fully contained in the portion of the bandwidth in which the CORESET is configured, and each next lower significant bit corresponds to the next lowest frequency group that is fully contained in the portion of the bandwidth in which the CORESET is configured, if any.

The ControlResourceSetId IE relates to a short identity, which is used to identify a set of control resources within a serving cell. ControlResourceSetId ═ 0 identifies a ControlResourceSet that is configured in ServingCellConfigCommon via pbch (mib). The ID space is used across BWPs of the serving cell. The number of CORESET per BWP is limited to 3 (including the initial CORESET).

The IE SearchSpace defines how/where to search for PDCCH candidates. Each search space is associated with a ControlResourceSet. The IE searchspacleid may be used to identify the search space. The search space with SearchSpaceId 0 identifies the search space configured via pbch (mib) and in ServingCellConfigCommon. The number of search spaces per BWP may be limited to 10, including the initial search space. The BWP downlink-specific sequence 310 may include information and sequences (e.g., PDCCH configuration) for configuring the element PDCCH-Config.

The PDCCH-Config Information Element (IE) may be used to configure UE-specific PDCCH parameters such as control resource set (CORESET), search space, and additional parameters for acquiring PDCCH. The PDCCH-Config information element may include information for PDCCH configuration, such as PDCCH-Config SEQUENCE, which includes a list of UE-specifically configured control resource sets (CORESET) to be used by UE 110. The PDCCH-Config information element may also include a list of UE-specifically configured control resource sets (CORESET). The network 100 may configure up to 10 search spaces per BWP per cell (including the initial search space).

With respect to the configuration of the control resource set, PDCCH configuration sequence 320 may include information for configuring UE110 with control resource set 330 and search space 340. Control resource set configuration 330 may include a list of UE-specifically configured control resource set (CORESET) information, such as would be used by UE 110. The network 100 may configure the UE with a maximum of 3 CORESET per BWP per cell (including the initial CORESET # 0). The controlResourceSetToAddModList corresponds to the sequence of controlresourcesets (size (1.. 3)). Alternatively, the controlresourcesetttoreleaselist may correspond to the sequence of ControlResourceSetId (size (1.. 3)).

With respect to the configuration of the search space, search space configuration information 340 may include a list of UE-specifically configured control resource sets (CORESET) to be used by UE 110. The network 100 may configure the UE with up to 10 search spaces per BWP per cell (including initial search space # 0).

In the case of DL BW "breathing" with BW adaptation, when the DL data buffer is empty, the gNB 170 dynamically switches between narrow DL BWPs and wide DL BWPs to reduce power consumption at the UE, and the gNB 170 may operate one UL BWP and two DL BWPs. However, working assumptions for one-to-one mapping may require that UE 1210-1 (shown in FIG. 2) switch to DL BWP1 during RA, even though CSS ID 0 is shared by DL BWP1 and DL BWP2 and UE 210-1 is able to receive RARs from DL BWP2, from CCS ID 0. This may lead to unnecessary BWP handover and service interruption due to RF retuning and due to the NW not knowing the UE DL BWP handover before the RA procedure is completed. Unnecessary signaling overhead to switch the UE back to the previously utilized DL BWP may also be incurred by the network. The example embodiments mitigate this undesirable situation and (e.g., for DL BW adaptation) allow for performance improvements of the network 100, which is the main use case for BWP.

Referring back to fig. 2, the example scenario illustrates an instance where UE 1210-1 and UE2210-2 are in the same cell and are configured with the same UL BWP 1. UE 1210-1 is configured with DL BWP1 as the initial BWP and default BWP and DL BWP2 with a wider BW than that of DL BWP 1. BWPs may overlap and share the same CSS 0. As a UE with limited BW capability, UE2210-2 may be configured with DL BWP1 having the same initial BWP as UE 1210-1, and DL BWP2 having the same BW as DL BWP1 for load balancing. For UE 210-2, the gNB may associate the PRACH with an SS ID of 0 or an SS ID of 1.

These example embodiments provide a solution for instances in which the same UL PRACH resources are configured, when UEs 110 (e.g., UE 1210-1 and UE 2210-2) are performing contention-based RACH, the gNB 170 may not know on which DL BWP a particular UE110 is operating, and may therefore need to transmit on DL BWPs if it is not going to do so without any link for RAR reception₁CSS ID 0 and DL BWP₂RAR is sent for UE2210-2 on both CSS ID 1 above. The search space may be configured with an ID, and the configuration may also inform whether it is generic or user specific (e.g., CSS or USS, such as SS ID).

For UE 1210-1, CSS0 may be configured for RAR and/or MSG4 (Contention resolution message in RA procedure) for UL BWP₁PRACH of (2). No matter which DL BWP UE110 is operating on when performing RACH, UE 1210-1 may not need to handover DL BWP. After the RACH procedure, the UE 1210-1 may also stay on the currently operating BWP. In contrast, however, in the case of one-to-one BWP ID chaining, even though the UE 1210-1 may already receive RARs there, if the UE 1210-1 is DL BWP₂Up running, the UE 1210-1 may still need (e.g., may need) to handover DL BWP₁。

With respect to UE2210-2, the gNB 170 may have configuration flexibility to receive configuration CSS0 or CSS1 for RAR and/or MSG 4. In the case where gNB 170 determines to keep UE2210-2 operating primarily on DL BWP2 and avoid UE autonomous handover, gNB 170 may configure CSS1 for RAR and send RAR on CSS1 and CCS0 when gNB 170 obtains a contention-based preamble. In contrast, however, in the event that gNB 170 determines to minimize RAR overhead, gNB 170 may configure UE2210-2 with CSS0, meaning that UE2210-2 may need to be handed over to DL BWP when UE2210-2 performs RACH₁。

According to an embodiment, the UE110 may be configured with at least one common search space identifier for a corresponding PRACH on at least one uplink bandwidth portion. Additionally, UE110 may be configured with one or more common search space identifiers on at least one downlink bandwidth portion. When the UE110 initiates an RA procedure and switches its DL BWP based on at least one common search space identifier, the UE110 may receive the corresponding RAR and/or MSG4 on any common search space available in the active DL BWP (whether or not the CSS ID is explicitly configured for the PRACH).

In some instances, instead of configuring at least one common search space identifier, UE110 may be configured with at least one CORESET identifier for a corresponding PRACH on at least one uplink bandwidth portion. Thus, example embodiments may be similarly applicable to CORESET identifiers, as they are directed to common search space identifiers.

Fig. 4 is an example flow diagram 400 of a method that may be performed by an apparatus (e.g., UE110 described herein) according to an example embodiment.

At block 410, the UE110 may be configured with at least one common search space identifier for a corresponding PRACH on at least one uplink bandwidth portion.

At block 420, UE110 may determine whether a transmission can be received on the associated common search space identifier for the active downlink bandwidth portion.

At block 430, UE110 may determine to switch downlink bandwidth portions based on whether the user terminal may initiate a random access procedure based on receiving a transmission on an associated common search space identifier for the active downlink bandwidth portion.

At block 440, if the UE110 has to switch its DL BWP, the UE110 may determine (e.g., explicitly and/or alternatively, implicitly) which BWP to select.

Without in any way limiting the scope, interpretation, or application of the claims appearing below, a technical effect of one or more of the example embodiments disclosed herein is that a UE may explicitly configure a Common Search Space (CSS) ID for RAR and/or MSG4 reception for a corresponding PRACH on UL BWP. Another technical effect is that the UE may decide whether to handover its DL BWP after initiating the random access procedure based on whether it can receive on the associated CSS on the active DL BWP.

Example embodiments may provide a method comprising: receiving, at a user terminal, a configuration of at least one common search space identifier for a corresponding physical random access channel on at least one uplink bandwidth portion; determining whether at least one transmission is received on the associated at least one common search space identifier for at least one active downlink bandwidth portion; and determining whether to switch the downlink bandwidth part after initiating a random access procedure based on whether the user terminal received a transmission on the associated at least one common search space identifier for the at least one active downlink bandwidth part.

According to an example embodiment described in the preceding paragraph, a configuration of at least one common search space identifier is received for at least one of a random access channel response and a medium access control message 4 reception.

According to an example embodiment described in the preceding paragraph, wherein the at least one common search space identifier is configured using at least one control resource set identifier associated with the at least one common search space identifier.

According to the exemplary embodiment described in the above paragraph, it is determined which bandwidth part to select if the user terminal has to switch at least one active bandwidth part.

According to an example embodiment described in the preceding paragraph, it is determined that a downlink bandwidth part having one of the following is to be selected: a lower downlink bandwidth part index and a higher downlink bandwidth part index containing the configured at least one common search space identifier.

According to an example embodiment described in the preceding paragraph, it is determined that a downlink bandwidth part having one of the following is to be selected: a narrower downlink bandwidth portion and a wider downlink bandwidth portion containing the configured at least one common search space identifier.

According to the example embodiments described in the preceding paragraphs, the determining of the downlink bandwidth part is to be selected from an initial downlink bandwidth part on any specially configured downlink bandwidth part.

According to the example embodiments described in the above paragraphs, the determining of the downlink bandwidth part is to be selected from a default downlink bandwidth part on any other configured downlink bandwidth part.

According to an example embodiment described in the preceding paragraph, a configuration is received indicating a downlink bandwidth part to be selected when switching the downlink bandwidth part.

According to an example embodiment described in the above paragraph, a configuration of a first downlink bandwidth part and a second downlink bandwidth part is received, wherein the first downlink bandwidth part is at least one of an initial bandwidth part and a default bandwidth part, and the second downlink bandwidth part comprises a wider bandwidth than the default bandwidth part.

According to an example embodiment described in the preceding paragraph, receiving a configuration of a common search space for a random access channel response; and transmitting at least one random access channel response on both the first common search space and the second common search space in response to receiving the preamble.

According to an example embodiment described in the above paragraph, the configuration of the common search space is received when performing a random access channel response.

Example embodiments may be provided in an apparatus comprising at least one processor; and at least one non-transitory memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to: receiving a configuration of at least one common search space identifier for a corresponding physical random access channel on at least one uplink bandwidth portion; determining whether at least one transmission is received on the associated at least one common search space identifier for at least one active downlink bandwidth portion; and determining whether to switch the downlink bandwidth part after initiating a random access procedure based on whether the user terminal received a transmission on the associated at least one common search space identifier for the at least one active downlink bandwidth part.

According to the exemplary embodiment described in the above paragraph, it is determined which bandwidth part to select if the user terminal has to switch to at least one active bandwidth part.

According to an example embodiment described in the preceding paragraph, it is determined that a downlink bandwidth portion having one of: a lower downlink bandwidth part index and a higher downlink bandwidth part index.

According to an example embodiment described in the preceding paragraph, it is determined that a downlink bandwidth portion having one of: a narrower downlink bandwidth portion and a wider downlink bandwidth portion.

According to an example embodiment described in the above paragraph, the determining of the downlink bandwidth part is to be selected from a default downlink bandwidth part of any other configured downlink bandwidth part.

According to another example, an example apparatus includes: means for receiving a configuration of at least one common search space identifier for a corresponding physical random access channel on at least one uplink bandwidth portion; means for determining whether at least one transmission is received on the associated at least one common search space identifier for at least one active downlink bandwidth portion; and means for determining whether to switch the downlink bandwidth part after initiating a random access procedure based on whether the user terminal received a transmission on the associated at least one common search space identifier for the at least one active downlink bandwidth part.

According to an example embodiment described in the preceding paragraph, means for receiving a configuration of at least one common search space identifier for at least one of a random access channel response and a medium access control message 4 reception.

According to an example embodiment described in the above paragraph, the means for determining which bandwidth part to select in case the user terminal has to switch to at least one active bandwidth part.

According to an example embodiment described in the preceding paragraph, means for determining that a downlink bandwidth part having one of: a lower downlink bandwidth part index and a higher downlink bandwidth part index.

According to an example embodiment described in the preceding paragraph, means for determining that a downlink bandwidth part having one of: a narrower downlink bandwidth portion and a wider downlink bandwidth portion

According to an example embodiment described in the preceding paragraph, means for determining that the downlink bandwidth part is to be selected from an initial downlink bandwidth part on any specially configured downlink bandwidth part.

According to an example embodiment described in the preceding paragraph, the means for receiving a configuration indicating a downlink bandwidth part to be selected when switching the downlink bandwidth part.

Embodiments herein may be implemented in software (executed by one or more processors), hardware (e.g., application specific integrated circuits), or a combination of software and hardware. In an example embodiment, the software (e.g., application logic, a set of instructions) is maintained on any of a variety of conventional computer-readable media. In the context of this document, a "computer-readable medium" can be any media or means that can contain, store, communicate, propagate, or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer, for example, one example of a computer described and depicted in FIG. 1. A computer-readable medium may include a computer-readable storage medium (e.g.,

memory

125, 155, 171, or other device) that may be any medium or means that can contain, store, and/or transport the instructions for use by or in connection with the instruction execution system, apparatus, or device. Computer-readable storage media do not include propagated signals.

If desired, the different functions discussed herein may be performed in a different order and/or concurrently with each other. Further, if desired, one or more of the above-described functions may be optional or may be combined.

While various aspects are set forth above, other aspects include other combinations of features from the described embodiments, not just the above.

It is also noted herein that while the above describes example embodiments, these descriptions should not be viewed in a limiting sense. Rather, various modifications and adaptations may be made without departing from the scope of the invention.

Although various aspects of the invention are set out in the independent claims, other aspects of the invention comprise other combinations of features from the described embodiments and/or the dependent claims with the features of the independent claims, and not solely the combinations explicitly set out in the claims.

It is also noted herein that while the above describes example embodiments, these descriptions should not be viewed in a limiting sense. Rather, various modifications and changes may be made without departing from the scope of the invention as defined in the appended claims.

In general, the various embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. The present invention is not limited thereto. While various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well known that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples: hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing device, or some combination thereof.

Embodiments may be practiced in various components, such as integrated circuit modules. The design of integrated circuits is generally a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

The word "exemplary" is used herein to mean "serving as an example, instance, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. All of the embodiments described in this detailed description are exemplary embodiments provided to enable persons skilled in the art to make or use the invention and not to limit the scope of the invention which is defined by the claims.

The foregoing description has provided by way of exemplary and non-limiting examples a full and informative description of the best method and apparatus presently contemplated by the inventors for carrying out the invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention.

It should be noted that the terms "connected," "coupled," or any variant thereof, refer to any direct or indirect connection or coupling between two or more elements and may encompass the presence of one or more intermediate elements between two elements that are "connected" or "coupled" together. The coupling or connection between the elements may be physical, logical, or a combination thereof. As employed herein, two elements may be considered "connected" or "coupled" together by the following as a few non-limiting and non-exhaustive examples: using one or more wires, cables, and/or printed electrical connections, and by using electromagnetic energy, such as electromagnetic energy having wavelengths in the radio frequency region, the microwave region, and the optical (visible and invisible) region.

Furthermore, some of the features of the preferred embodiments of this invention could be used to advantage without the corresponding use of other features. As such, the foregoing description should be considered as merely illustrative of the principles of the present invention, and not in limitation thereof.

Claims

1. A method, comprising:

receiving, at a user terminal, a configuration of at least one common search space identifier for a corresponding physical random access channel on at least one uplink bandwidth portion;

determining whether at least one transmission is received on an associated at least one common search space identifier for at least one active downlink bandwidth portion; and

determining whether to switch downlink bandwidth parts after initiating a random access procedure based on whether the user terminal receives a transmission on the associated at least one common search space identifier for the at least one active downlink bandwidth part.

2. The method of claim 1, wherein receiving a configuration of the at least one common search space identifier further comprises:

receiving a configuration of the at least one common search space identifier for at least one of a random access channel response and a medium access control message 4 reception.

3. The method of any of claims 1-2, wherein the at least one common search space identifier is configured using: at least one control resource set identifier associated with the at least one common search space identifier.

4. The method of any of claims 1 to 3, further comprising:

determining which bandwidth part to select if the user terminal has to switch the at least one active bandwidth part.

5. The method of any of claims 1 to 4, further comprising:

determining that the downlink bandwidth portion having one of: a lower downlink bandwidth part index and a higher downlink bandwidth part index containing the at least one configured common search space identifier.

6. The method according to any one of claims 1-5, further comprising:

determining that the downlink bandwidth portion having one of: a narrower downlink bandwidth portion and a wider downlink bandwidth portion, the narrower downlink bandwidth portion and wider downlink bandwidth portion containing the at least one common search space identifier configured.

7. The method of any of claims 1 to 6, further comprising:

determining that the downlink bandwidth part is to be selected from an initial downlink bandwidth part on any specially configured downlink bandwidth part.

8. The method of any of claims 1 to 6, further comprising:

determining that the downlink bandwidth part is to be selected from a default downlink bandwidth part on any other configured downlink bandwidth part.

9. The method of any of claims 1 to 8, further comprising:

receiving a configuration indicating a downlink bandwidth portion to be selected when switching the downlink bandwidth portion.

10. The method of any of claims 1 to 9, further comprising:

receiving a configuration of a first downlink bandwidth portion and a second downlink bandwidth portion, wherein the first downlink bandwidth portion is at least one of an initial bandwidth portion and a default bandwidth portion, and the second downlink bandwidth portion includes a bandwidth wider than the default bandwidth portion.

11. The method of any of claims 1 to 10, further comprising:

receiving a configuration of a common search space for a random access channel response; and

at least one random access channel response is transmitted on both the first common search space and the second common search space in response to receiving the preamble.

12. The method according to any of claims 1 to 11, receiving a configuration of a common search space when performing a random access channel response.

13. An apparatus, comprising:

at least one processor; and

at least one memory including computer program code,

the at least one memory and the computer program code configured, with the at least one processor, to cause the apparatus at least to:

receiving a configuration of at least one common search space identifier for a corresponding physical random access channel on at least one uplink bandwidth portion;

14. The apparatus of claim 13, wherein when receiving the configuration of the at least one common search space identifier, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus at least to:

15. The apparatus of any of claims 13 to 14, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus at least to:

16. The apparatus of any of claims 13 to 15, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus at least to:

17. The apparatus of any of claims 13 to 16, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus at least to:

18. The apparatus of any of claims 13 to 17, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus at least to:

19. The apparatus of any of claims 13 to 18, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus at least to:

20. The apparatus according to any of claims 12 to 18, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus at least to:

21. A non-transitory computer-readable medium encoded with instructions that, when executed by a computer, cause performance of a method comprising:

determining whether at least one transmission can be received on the associated at least one common search space identifier for at least one active downlink bandwidth portion; and

determining whether to switch downlink bandwidth parts after initiating a random access procedure based on whether the user terminal is capable of receiving transmissions on the associated at least one common search space identifier for the at least one active downlink bandwidth part.