WO2019196066A1

WO2019196066A1 - Random access response for bwp

Info

Publication number: WO2019196066A1
Application number: PCT/CN2018/082869
Authority: WO
Inventors: Chunli Wu; Samuli Turtinen; Dawid Koziol; Karol Schober
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy; Nokia Technologies Oy
Priority date: 2018-04-12
Filing date: 2018-04-12
Publication date: 2019-10-17
Also published as: CN111919472A; CN111919472B

Abstract

Methods include receiving configuration, at a user terminal, of at least one common search space identifier for a corresponding physical random access channel on at least one uplink bandwidth part. The methods also include 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 part. The methods further include determining whether to switch a downlink bandwidth part upon initiation of random access procedure based on whether the user terminal receives transmissions 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 particularly, to downlink control channel transmission and reception.

BACKGROUND:

In meetings of 3GPP RAN2, agreement was made for random access to be supported on different BWPs. Agreement was also made that common search space may be configured on any DL BWP to send the Random Access Channel (RACH) Response (RAR) .

To avoid sending multiple RAR from multiple DL BWP, the RAN2 meeting determined the following working assumptions. For Frequency Division Duplex (FDD) and Contention BASED Random Access (CBRA) , PRACH configuration/resources are linked with DL BWPs (implicitly or explicitly) . The UE only monitors RAR on DL BWPs that are linked to the used PRACH resources. UL BWP with BWP index k is linked with DL BWP k (for example, with the same BWP indexed) . If the UE intends to transmit preamble on UL BWP k, then the active DL BWP has to be DL BWP k.

Certain abbreviations that may be found in the description and/or in the Figures are herewith defined as follows:

BWP Bandwidth part

CA Carrier aggregation

CC Component carrier

CE Control Element

CORESET Control resource set

CSS Common search space

DAI Downlink Assignment Index

DCI Downlink Control Information

DL Downlink

gNB 5G Enhanced Node B (Base station)

LTE long term evolution

MEC multi-access edge computing

MME mobility management entity

NCE network control element

NR New radio

NR-PDCCH New radio Physical Downlink Control Channel

N/W Network

PBCH Physical Broadcast Channel

PDCCH Physical Downlink Control Channel

PDSCH Physical Downlink Shared Channel

PRACH physical random access channel

RE Resource Element

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

SUMMARY:

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

In accordance with one aspect, an example method comprises receiving configuration, at a user terminal, of at least one common search space identifier for a corresponding physical random access channel on at least one uplink bandwidth part. The methods also include determining whether at least one transmission can be received on an associated at least one common search space identifier for at least one active downlink bandwidth part. The methods further include determining whether to switch a downlink bandwidth part upon initiation of random access procedure based on whether the user terminal can receive transmissions on the associated at least one common search space identifier for the at least one active downlink bandwidth part.

In accordance with another aspect, an example apparatus comprises 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 may be configured to, with the at least one processor, cause the apparatus to: receive configuration of at least one common search space identifier for a corresponding physical random access channel on at least one uplink bandwidth part, determine whether at least one transmission can be received on an associated at least one common search space identifier for at least one active downlink bandwidth part, and determine whether to switch a downlink bandwidth part upon initiation of random access procedure based on whether the user terminal can receive transmissions on the associated at least one common search space identifier for the at least one active downlink bandwidth part.

In accordance with another aspect, an example apparatus comprises means for receiving configuration of at least one common search space identifier for a corresponding physical random access channel on at least one uplink bandwidth part; means for determining whether at least one transmission can be received on an associated at least one common search space identifier for at least one active downlink bandwidth part; and means for determining whether to switch a downlink bandwidth part upon initiation of random access procedure based on whether the user terminal can receive transmissions on the associated at least one common search space identifier for the at least one active downlink bandwidth part.

BRIEF DESCRIPTION OF THE DRAWINGS:

The foregoing and other aspects of embodiments of this invention are made more evident in the following Detailed Description, when read in conjunction with the attached Drawing Figures, wherein:

Fig. 1 is a block diagram of one possible and non-limiting example system in which the 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 in accordance with example embodiments which may be performed by an apparatus.

DETAILED DESCRIPTION:

In the example embodiments as described herein a method and apparatus that provides a random access response for bandwidth parts.

Turning to Fig. 1, this figure shows a block diagram of one possible and non-limiting example system in which the 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 can access a wireless network. The UE 110 includes one or more processors 120, one or more memories 125, and one or more transceivers 130 interconnected through 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 lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, and the like. The one or more transceivers 130 are connected to one or more antennas 128. The one or more memories 125 include computer program code 123. The UE 110 includes a signaling module 140, comprising one of or both parts 140-1 and/or 140-2, which may be implemented in a number of ways. The signaling module 140 may be implemented in hardware as signaling module 140-1, such as being implemented as part of the one or more processors 120. The signaling module 140-1 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the signaling module 140 may be implemented as signaling module 140-2, which is implemented as computer program code 123 and is executed by the one or more processors 120. For instance, 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 of the operations as described herein. The UE 110 communicates with eNB 170 via a 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 by wireless devices such as the UE 110 to the wireless network 100. The gNB 170 includes one or more processors 152, one or more memories 155, one or more network interfaces (N/W I/F (s) ) 161, and one or more transceivers 160 interconnected through one or more buses 157. Each of the one or more transceivers 160 includes a receiver, Rx, 162 and a transmitter, Tx, 163. The 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 report module 150, comprising one of or both parts 150-1 and/or 150-2, which may be implemented in a number of ways. The report module 150 may be implemented in hardware as report module 150-1, such as being implemented as part of the one or more processors 152. The report module 150-1 may be implemented also as an integrated circuit or through other hardware such as a programmable gate array. In another example, the report module 150 may be implemented as report module 150-2, which is implemented as computer program code 153 and is executed by the one or more processors 152. For instance, the one or more memories 155 and the computer program code 153 are configured to, with the one or more processors 152, cause the gNB 170 to perform one or more of the operations as described herein. The one or more network interfaces 161 communicate over a network such as via the

links

176 and 131. Two or more gNBs 170 communicate using, e.g., link 176. The link 176 may be wired or wireless or both and may implement, e.g., 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 lines on a motherboard or integrated circuit, fiber optics or other optical communication equipment, wireless channels, and the like. For example, the one or more transceivers 160 may be implemented as a remote radio head (RRH) 195, with the other elements of the gNB 170 being physically in a different location from the RRH, and the one or more buses 157 could be implemented in part as fiber optic cable to connect the other elements of the gNB 170 to the RRH 195.

It is noted that description herein indicates that “cells” perform functions, but it should be clear that the gNB that forms the cell will perform the functions. The cell makes up part of a gNB. That is, there can be multiple cells per gNB. Each cell may contain one or multiple transmission and receiving points (TRPs) .

The wireless network 100 may include a network control element (NCE) 190 that may include MME (Mobility Management Entity) /SGW (Serving Gateway) functionality, and which provides connectivity with a further network, such as a telephone network and/or a data communications network (e.g., the Internet) . The gNB 170 is coupled via a link 131 to the NCE 190. The link 131 may be implemented as, e.g., an S1 interface. The NCE 190 includes one or more processors 175, one or more memories 171, and one or more network interfaces (N/W I/F (s) ) 180, interconnected through 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.

The wireless network 100 may implement network virtualization, which is the process of combining hardware and software network resources and network functionality into a single, software-based administrative entity, a virtual network. Network virtualization involves platform virtualization, often combined with resource virtualization. Network virtualization is categorized as either external, combining many networks, or parts of networks, into a virtual unit, or internal, providing network-like functionality to software containers on a single system. Note that the virtualized entities that result from the network virtualization are still implemented, at some level, using hardware such as

processors

152 or 175 and

memories

155 and 171, and also such virtualized entities create technical effects.

The computer

readable memories

125, 155, and 171 maybe 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 maybe means for performing storage functions. The

processors

120, 152, and 175 may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on a multi-core processor architecture, as non-limiting examples. The

processors

120, 152, and 175 may be means for performing functions, such as controlling the UE 110, gNB 170, and other functions as described herein.

In general, the various embodiments of the user equipment 110 can include, but are not limited to, cellular telephones such as smart phones, tablets, 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, tablets with wireless communication capabilities, as well as 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., an application specific integrated circuit) , or a combination of software and hardware. In an example of an embodiment, the software (e.g., application logic, an instruction set) is maintained on any one of various 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 or in connection with an instruction execution system, apparatus, or device, such as a computer, with one example of a computer described and depicted, e.g., in Fig. 1. A computer-readable medium may comprise a computer-readable storage medium or other device that may be any media 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 requires bringing the content close to the radio which leads to local break out and multi-access edge computing (MEC) . 5G may use edge cloud and local cloud architecture. Edge computing covers a wide range of technologies such as wireless sensor networks, mobile data acquisition, mobile signature analysis, cooperative distributed peer-to-peer ad hoc networking and processing also classifiable as local cloud/fog computing and grid/mesh computing, dew computing, mobile edge computing, cloudlet, distributed data storage and retrieval, autonomic self-healing networks, remote cloud services and augmented reality. In radio communications, using edge cloud may mean node operations to be carried out, at least partly, in a server, host or node operationally coupled to a remote radio head or base station comprising radio parts. It is also possible that node operations will be distributed among a plurality of servers, nodes or hosts. It should also be understood that the distribution of labor between core network operations and base station operations may differ from that of the LTE or even be non-existent. Some other technology advancements probably to be used are Software-Defined Networking (SDN) , Big Data, and all-IP, which may change the way networks are being constructed and managed.

Example embodiments may be implemented in network backhaul. Example embodiments may also be implemented in relay nodes (for example, with regard to functions described herein below with respect to UE 110) . Furthermore, in a multi-hop relay scenario, a radio network (RN) , for example network 100, may implement functionality described with respect to gNB 170 herein below.

Having thus introduced one suitable but non-limiting technical context for the practice of the example embodiments of this invention, the example embodiments will now be described with greater specificity.

Fig. 2 illustrates an example 200 of different configuration of multiple DL BWP. Two UEs 110, such as UE1 210-1 and UE2 210-2 maybe configured with the same DL BWP1 including Coreset id=0 and SS id=0 (CSS) .

For a single UE, the signalling structure of PDCCH configuration for BWP may allow the network to configure the same CORESET/search space for multiple BWPs when they overlap, for example, UE 1 210-1 configured with C SS0 for both DL BWP ₁ (230-1) and DL BWP ₂ (235-1) in Fig. 2.

As shown in Fig. 2, one user device UE 110, such as UE1 210-1 may be configured with a DL BWP ₁ (230-1) , with a Coreset id=0 and SS id=0 (CSS) (240-1) and a DL BWP ₂ (235-1) (for example, 40 MHz) , which may be measured along a frequency axis 220. The UE1 210-1 may also be configured with a UL BWP1 250-1. Another user device UE 110, such as UE2 210-2 may be configured with a DL BWP ₁ (for example, and initial BWP of 10 MHz 230-2) , with a Coreset id=0 and SS id=0 (CSS) (240-2-0) and a DL BWP ₂ (235-2) with a Coreset id=1 and SS id=1 (CSS) (240-2-1) .

The example embodiments may, instead of linking DL BWP k to UL BWP k, explicitly configure Common Search Space (CSS) ID for RAR and/or msg4 reception on DL BWP for the corresponding PRACH on UL BWP. UE 110 may decide whether to switch its DL BWP upon initiation of Random Access procedure based on whether it can receive on the associated CSS on the active DL BWP, for example, based on whether the CSS is associated with the UE’s active DL BWP when performing the random access. According to an example embodiment, the PRACH on UL BWP may be associated to CORESET/CSS, but not to the UE’s DL BWP, to avoid unnecessary switching of DL BWP during PRACH procedure. The search-space configuration contains an association to CORESET ID, and therefore an association between a CORESET and user-specific as well as common search spaces within the CORESET is known to UE 110.

In instances in which the UE 110 has to switch its active DL BWP and there are multiple DL BWPs from where to receive the RAR for (example, the same CSS ID is associated to both) , the UE 110 may select DL BWPs based on the following selection principles or combinations thereof. The DL BWP with lower/higher BWP index that contains the configured CSS may be selected. The DL BWP with narrower/wider BW that contains the configured CSS may be selected. Initial DL BWP is selected over any dedicatedly configured DL BWP. Default DL BWP is selected over any other configured DL BWP. NW may configure explicitly which one to select if the UE 110 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.

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

The ControlResourceSetId IE concerns a short identity, used to identify a control resource set within a serving cell. The ControlResourceSetId = 0 identifies the ControlResourceSet configured via PBCH (MIB) and in ServingCellConfigCommon. The ID space is used across the BWPs of a Serving Cell. The number of CORESETs 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 one ControlResourceSet. The IE SearchSpaceId may be used to identify Search Spaces. The search space with the 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. BWP downlink dedicated sequence 310 may include information and a sequence for configuration elements pdcch-Config (for example, PDCCH configuration) .

The PDCCH-Config information element (IE) may be used to configure UE specific PDCCH parameters such as control resource sets (CORESET) , search spaces and additional parameters for acquiring the PDCCH. A PDCCH-Config information element may include information for PDCCH configuration, such as a PDCCH-Config SEQUENCE, including a list of UE specifically configured Control Resource Sets (CORESETs) to be used by the UE 110. The PDCCH-Config information element may also include a list of UE specifically configured Control Resource Sets (CORESETs) . The network 100 may configures at most 10 Search Spaces per BWP per cell (including the initial Search Space) .

With regard to configuration of control resource sets, PDCCH configuration sequence 320 may include information for configuring the UEs 110 with control resource sets 330 and search spaces 340. The control resource set configuration 330 may include information such as a list of UE specifically configured Control Resource Sets (CORESETs) to be used by the UE 110. The network 100 may configure the UE with at most 3 CORESETs per BWP per cell (including the initial CORESET#0) . controlResourceSetToAddModList corresponds to sequence (size (1..3) ) of ControlResourceSet. Optionally, controlResourceSetToReleaseList may correspond to sequence (size (1..3) ) of ControlResourceSetId.

With regard to configuration of search spaces, the search space configuration information 340 may include a list of UE specifically configured Control Resource Sets (CORESETs) to be used by the UE 110. The network 100 may configure the UE with at most 10 search-spaces per BWP per cell (including the initial search space #0) .

In instances of DL BW “breathing” with BW adaptation, where gNB 170 dynamically switches between narrow and wide DL BWPs to reduce power consumption at the UE when DL data buffer is empty, gNB 170 may operate one UL BWP and two DL BWPs. However, a working assumption of one to one mapping may require UE 1 210-1, such as shown in Fig. 2, to switch during RA procedure to DL BWP 1 even if the CSS ID 0 are shared for DL BWP 1 and DL BWP 2 and the UE 210-1 is capable to receive RAR from CCS ID 0 from DL BWP 2 as well. This may introduce unnecessary BWP switching and interruption in service due to RF retuning as well as due to NW being unaware of the UE DL BWP switching before the RA procedure is completed. Unnecessary signalling overhead may also be incurred by the network to switch back the UE to previously utilized DL BWP. The example embodiments alleviate this undesirable condition and allow improved performance of the network 100, for example with regard to DL BW adaptation, which is a major use case for BWP.

Referring back to Fig. 2, an example scenario illustrates an instance in which UE1 210-1 and UE2 210-2 are in a same cell and are configured with same UL BWP1. UE1 210-1 is configured with DL BWP1 which is the initial BWP as well as default BWP, and DL BWP 2 with wider BW than the BW of the DL BWP1. The BWPs may overlap and share the same CSS0. UE2 210-2, being a UE with limited BW capability, may be configured with DL BWP1 which is the initial BWP same as UE1 210-1, and DL BWP 2 with same BW as DL BWP 1 for load balancing purpose. For UE 210-2 gNB may associate PRACH to either SS ID=0 or SS ID=1.

These example embodiments provide a solution to instances in which same UL PRACH resource configured, when the UEs 110 (for example, UE1 210-1 and UE2 210-2) are performing contention based RACH, the gNB 170 may not know which DL BWP the particular UE 110 is operating on and may therefore need to send RAR on both CSS ID 0 on DL BWP ₁ and CSS ID 1 on DL BWP ₂ for the UE2 210-2 if the transmission is to be made without any linking for RAR reception. Search-space may be configured with ID, and configuration also tells whether it is common or user-specific, for example, CSS or USS, such as SS ID.

For UE1 210-1, CSS0 may be configured for RAR and/or MSG4 (Contention Resolution Message in RA procedure) reception for PRACH on UL BWP ₁. The UE1 210-1 may not need to switch DL BWP regardless of which DL BWP the UE 110 is operating on when performing RACH. After the RACH procedure, UE1 210-1 may stay on a current operating BWP as well. While, in contrast, in instance of one-one BWP ID linking, the UE1 210-1 may be required (for example, may need) to switch DL BWP ₁ if UE1 210-1 is operating on DL BWP ₂ even if UE1 210-1 can already receive RAR there.

With regard to UE2 210-2, gNB 170 may have the configuration flexibility to configure CSS0 or CSS1 for RAR and/or MSG4 reception. In instances in which gNB 170 determines to keep the UE2 210-2 mainly operating on DL BWP 2 and avoid UE autonomous switching, gNB 170 may configure CSS1 for RAR and sending RAR on both CSS1 and CCS0 when gNB 170 gets a contention based preamble. While, in contrast, in instances in which gNB 170 determines to minimise RAR overhead, gNB 170 may configure the UE2 210-2 with CSS0 which implies the UE2 210-2 may be required to switch to DL BWP ₁ when UE2 210-2 is performing RACH.

According to an embodiment, UE 110 may be configured with at least one common search space identifier for a corresponding PRACH on at least one uplink bandwidth part. The UE 110 may additionally be configured with one or more common search space identifiers on at least one downlink bandwidth part. When the UE 110 initiates RA procedure and switches its DL BWP based on at least one common search space identifier, the UE 110 may receive the corresponding RAR and/or MSG4 on any of the common search spaces available in the activated DL BWP (regardless of whether the CSS ID was configured explicitly for PRACH or not) .

In some instances, instead of configuring at least one common search space identifier, UE 110 may be configured with at least one CORESET identifier for a corresponding PRACH on at least one uplink bandwidth part. The example embodiments may thereby be similarly applicable to CORESET identifier as they are for common search space identifier.

Fig. 4 is an example flow diagram 400 of a method in accordance with example embodiments which may be performed by an apparatus, for example, a UE 110 as described herein.

At block 410, UE 110 may be configured with at least one common search space identifier for a corresponding PRACH on at least one uplink bandwidth part.

At block 420, UE 110 may determine whether a transmission can be received on an associated common search space identifier for an active downlink bandwidth part.

At block 430, UE 110 may determine to switch a downlink bandwidth part upon initiation of random access procedure based on whether the user terminal can receive transmissions on the associated common search space identifier for the active downlink bandwidth part.

At block 440, UE 110 may determine (for example, explicitly and/or alternatively, implicitly) which BWP to select if the UE 110 has to switch its DL BWP.

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 common search space (CSS) ID for RAR and/or MSG4 reception for the corresponding PRACH on UL BWP. Another technical effect is that the UE may decide whether to switch its DL BWP upon initiation of Random Access procedure based on whether it can receive on the associated CSS on the active DL BWP.

An example embodiment may provide a method comprising performing receiving configuration, at a user terminal, of at least one common search space identifier for a corresponding physical random access channel on at least one uplink bandwidth part; 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 part; and determining whether to switch a downlink bandwidth part upon initiation of random access procedure based on whether the user terminal receives transmissions on the associated at least one common search space identifier for the at least one active downlink bandwidth part.

In accordance with the example embodiments as described in the paragraphs above, receiving configuration of the at least one common search space identifier for at least one of random access channel response and media access control message 4 reception.

In accordance with the example embodiments as described in the paragraphs above, wherein the at least one common search space identifier is configured using at least one control resource sets identifier associated with the at least one common search space identifier.

In accordance with the example embodiments as described in the paragraphs above, determining which bandwidth part to select if the user terminal has to switch the at least one active bandwidth part.

In accordance with the example embodiments as described in the paragraphs above, determining that the downlink bandwidth part is to be selected with one of a lower downlink bandwidth part index and a higher downlink bandwidth part index that contains the configured at least one common search space identifier.

In accordance with the example embodiments as described in the paragraphs above, determining that the downlink bandwidth part is to be selected with one of a narrower downlink bandwidth part and a wider downlink bandwidth part that contains the configured at least one common search space identifier.

In accordance with the example embodiments as described in the paragraphs above, determining that the downlink bandwidth part is to be selected from an initial downlink bandwidth part over any dedicatedly configured downlink bandwidth part.

In accordance with the example embodiments as described in the paragraphs above, determining that the downlink bandwidth part is to be selected from a default downlink bandwidth part over any other configured downlink bandwidth part.

In accordance with the example embodiments as described in the paragraphs above, receiving configuration indicating a downlink bandwidth part to select when switching the downlink bandwidth part.

In accordance with the example embodiments as described in the paragraphs above, receiving configuration of a first downlink bandwidth part and a second downlink bandwidth part, 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 includes a wider bandwidth than the default bandwidth part.

In accordance with the example embodiments as described in the paragraphs above, receiving configuration of common search space for random access channel response; and sending at least one random access channel response on both a first common search space and second common search space in response to receiving a preamble.

In accordance with the example embodiments as described in the paragraphs above, receiving configuration of common search space when performing random access channel response.

An example embodiment 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 may be configured to, with the at least one processor, cause the apparatus to: receive configuration of at least one common search space identifier for a corresponding physical random access channel on at least one uplink bandwidth part; determine whether at least one transmission can be received on an associated at least one common search space identifier for at least one active downlink bandwidth part; and determine whether to switch a downlink bandwidth part upon initiation of random access procedure based on whether the user terminal can receive transmissions on the associated at least one common search space identifier for the at least one active downlink bandwidth part.

In accordance with the example embodiments as described in the paragraphs above, receive configuration of the at least one common search space identifier for at least one of random access channel response and media access control message 4 reception.

In accordance with the example embodiments as described in the paragraphs above, determine which bandwidth part to select if the user terminal has to switch the at least one active bandwidth part.

In accordance with the example embodiments as described in the paragraphs above, determine that the downlink bandwidth part is to be selected with one of a lower downlink bandwidth part index and a higher downlink bandwidth part index.

In accordance with the example embodiments as described in the paragraphs above, determine that the downlink bandwidth part is to be selected with one of a narrower downlink bandwidth part and a wider downlink bandwidth part.

In accordance with the example embodiments as described in the paragraphs above, determine that the downlink bandwidth part is to be selected from an initial downlink bandwidth part over any dedicatedly configured downlink bandwidth part.

In accordance with the example embodiments as described in the paragraphs above, determine that the downlink bandwidth part is to be selected from a default downlink bandwidth part over any other configured downlink bandwidth part.

In accordance with another example, an example apparatus comprises: means for receiving configuration of at least one common search space identifier for a corresponding physical random access channel on at least one uplink bandwidth part; means for determining whether at least one transmission can be received on an associated at least one common search space identifier for at least one active downlink bandwidth part; and means for determining whether to switch a downlink bandwidth part upon initiation of random access procedure based on whether the user terminal can receive transmissions on the associated at least one common search space identifier for the at least one active downlink bandwidth part.

In accordance with the example embodiments as described in the paragraphs above, means for receiving configuration of the at least one common search space identifier for at least one of random access channel response and media access control message 4 reception.

In accordance with the example embodiments as described in the paragraphs above, means for determining which bandwidth part to select if the user terminal has to switch the at least one active bandwidth part.

In accordance with the example embodiments as described in the paragraphs above, means for determining that the downlink bandwidth part is to be selected with one of a lower downlink bandwidth part index and a higher downlink bandwidth part index.

In accordance with the example embodiments as described in the paragraphs above, means for determining that the downlink bandwidth part is to be selected with one of a narrower downlink bandwidth part and a wider downlink bandwidth part.

In accordance with the example embodiments as described in the paragraphs above, means for determining that the downlink bandwidth part is to be selected from an initial downlink bandwidth part over any dedicatedly configured downlink bandwidth part.

In accordance with the example embodiments as described in the paragraphs above, means for means for receiving configuration indicating a downlink bandwidth part to select when switching the downlink bandwidth part.

Embodiments herein may be implemented in software (executed by one or more processors) , hardware (e.g., an application specific integrated circuit) , or a combination of software and hardware. In an example embodiment, the software (e.g., application logic, an instruction set) is maintained on any one of various 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 or in connection with an instruction execution system, apparatus, or device, such as a computer, with one example of a computer described and depicted, e.g., in Fig. 1. A computer-readable medium may comprise a computer-readable storage medium (e.g.,

memories

125, 155, 171 or other device) that may be any media or means that can contain, store, and/or transport the instructions for use by or in connection with an instruction execution system, apparatus, or device, such as a computer. A computer-readable storage medium does not comprise propagating signals.

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

Although various aspects are set out above, other aspects comprise other combinations of features from the described embodiments, and not solely the combinations described above.

It is also noted herein that while the above describes example embodiments, these descriptions should not be viewed in a limiting sense. Rather, there are several variations and modifications which may be made without departing from the scope of the present 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, there are several variations and modifications which may be made without departing from the scope of the present 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, although the 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 understood 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 devices, or some combination thereof.

Embodiments may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large 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 example 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, mean any connection or coupling, either direct or indirect, 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 can be physical, logical, or a combination thereof. As employed herein two elements may be considered to be "connected" or "coupled" together by the use of one or more wires, cables and/or printed electrical connections, as well as by the use of electromagnetic energy, such as electromagnetic energy having wavelengths in the radio frequency region, the microwave region and the optical (both visible and invisible) region, as several non-limiting and non-exhaustive examples.

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 invention, and not in limitation thereof.

Claims

A method, comprising:

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

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 part; and

determining whether to switch a downlink bandwidth part upon initiation of random access procedure based on whether the user terminal receives transmissions on the associated at least one common search space identifier for the at least one active downlink bandwidth part.
The method of claim 1, wherein receiving configuration of the at least one common search space identifier further comprises:

receiving configuration of the at least one common search space identifier for at least one of random access channel response and media access control message 4 reception.
The method according to any of claims 1 to 2, wherein the at least one common search space identifier is configured using at least one control resource sets identifier associated with the at least one common search space identifier.
The method according to any of claims 1 to 3, further comprising:

determining which bandwidth part to select ifthe user terminal has to switch the at least one active bandwidth part.
The method according to any of claims 1 to 4, further comprising:

determining that the downlink bandwidth part is to be selected with one of a lower downlink bandwidth part index and a higher downlink bandwidth part index that contains the configured at least one common search space identifier.
The method according to any of claims 1 to 5, further comprising:

determining that the downlink bandwidth part is to be selected with one of a narrower downlink bandwidth part and a wider downlink bandwidth part that contains the configured at least one common search space identifier.
The method according to any of claims 1 to 6, further comprising:

determining that the downlink bandwidth part is to be selected from an initial downlink bandwidth part over any dedicatedly configured downlink bandwidth part.
The method according to any of claims 1 to 6, further comprising:

determining that the downlink bandwidth part is to be selected from a default downlink bandwidth part over any other configured downlink bandwidth part.
The method according to any of claims 1 to 8, further comprising:

receiving configuration indicating a downlink bandwidth part to select when switching the downlink bandwidth part.
The method according to any of claims 1 to 9, further comprising:

receiving configuration of a first downlink bandwidth part and a second downlink bandwidth part, 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 includes a wider bandwidth than the default bandwidth part.
The method according to any of claims 1 to 10, further comprising:

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

sending at least one random access channel response on both a first common search space and second common search space in response to receiving a preamble.
The method according to any of claims 1 to 11, receiving configuration of common search space when performing random access channel response.
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:

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

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

determine whether to switch a downlink bandwidth part upon initiation of random access procedure based on whether the user terminal receives transmissions on the associated at least one common search space identifier for the at least one active downlink bandwidth part.
The apparatus of claim 13, wherein the at least one memory and the computer program code, when receiving configuration of the at least one common search space identifier, is further configured, with the at least one processor, to cause the apparatus at least to:

receive configuration of the at least one common search space identifier for at least one of random access channel response and media access control message 4 reception.
The apparatus according to any of claims 13 to 14, wherein the at least one memory and the computer program code is further configured, with the at least one processor, to cause the apparatus at least to:

determine which bandwidth part to select ifthe user terminal has to switch the at least one active bandwidth part.
The apparatus according to any of claims 13 to 15, wherein the at least one memory and the computer program code is further configured, with the at least one processor, to cause the apparatus at least to:

determine that the downlink bandwidth part is to be selected with one of a lower downlink bandwidth part index and a higher downlink bandwidth part index that contains the configured at least one common search space identifier.
The apparatus according to any of claims 13 to 16, wherein the at least one memory and the computer program code is further configured, with the at least one processor, to cause the apparatus at least to:

determine that the downlink bandwidth part is to be selected with one of a narrower downlink bandwidth part and a wider downlink bandwidth part that contains the configured at least one common search space identifier.
The apparatus according to any of claims 13 to 17, wherein the at least one memory and the computer program code is further configured, with the at least one processor, to cause the apparatus at least to:

determine that the downlink bandwidth part is to be selected from an initial downlink bandwidth part over any dedicatedly configured downlink bandwidth part.
The apparatus according to any of claims 13 to 18, wherein the at least one memory and the computer program code is further configured, with the at least one processor, to cause the apparatus at least to:

receive configuration indicating a downlink bandwidth part to select when switching the downlink bandwidth part.
The apparatus according to any of claims 12 to 18, wherein the at least one memory and the computer program code is further configured, with the at least one processor, to cause the apparatus at least to:

receive configuration of a first downlink bandwidth part and a second downlink bandwidth part, 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 includes a wider bandwidth than the default bandwidth part.
A non-transitory computer readable medium encoded with instructions that, when executed by a computer, cause performance of a method comprising:

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

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

determining whether to switch a downlink bandwidth part upon initiation of random access procedure based on whether the user terminal can receive transmissions on the associated at least one common search space identifier for the at least one active downlink bandwidth part.