CN117796033A

CN117796033A - Serving cell search

Info

Publication number: CN117796033A
Application number: CN202280011930.XA
Authority: CN
Inventors: L·达尔斯加德; 陈月姬
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Priority date: 2022-07-27
Filing date: 2022-07-27
Publication date: 2024-03-29
Also published as: WO2024020901A1

Abstract

Embodiments of the present disclosure relate to apparatuses, methods, devices, and computer-readable storage media for serving cell search. The method comprises determining a pattern for cell search, the pattern indicating at least that cell search is to be performed in parallel on a second frequency range (FR 2) in a New Radio (NR) and a respective carrier associated with at least one of: a first frequency range (FR 1) in Long Term Evolution (LTE) or NR, or cell search, is to be performed on a respective carrier associated with at least one of: FR1 or LTE that is searched before the corresponding carrier in FR 2; and performing a cell search based on the determined pattern. The scheme proposed in the present disclosure may allow a User Equipment (UE) time to perform cell search considering the maximum configured number of carriers without extending the allowed search time, and thus may avoid unnecessary UE long delays.

Description

Serving cell search

Technical Field

Embodiments of the present disclosure relate generally to the field of telecommunications and, more particularly, relate to an apparatus, method, device, and computer readable storage medium for serving cell search.

Background

Currently, the desired search time for a User Equipment (UE) to detect potential cells on a carrier depends on the Radio Access Technology (RAT) and, for a New Radio (NR), on whether the carrier is in frequency range 1 (FR 1) or frequency range 2 (FR 2). In case the UE detects that the serving cell quality no longer meets the cell selection criteria, the UE may search for configured carriers without interruption, regardless of any rules restricting UE measurement activity.

In Long Term Evolution (LTE), periodic cell detection and measurement associated with Primary Synchronization Signals (PSS), secondary Synchronization Signals (SSS), or Common Reference Signals (CRS) may be performed, while in NR, cell detection and measurement may be performed at each SSB or SMTC period (in ms) of the network configuration.

Disclosure of Invention

In general, example embodiments of the present disclosure provide a solution for serving cell search.

In a first aspect, a first device is provided. The first device includes at least one processor; at least one memory including computer program code; the at least one memory stores instructions that, when executed by the at least one processor, cause the first device to at least determine a pattern for cell search that indicates at least that cell search is to be performed in parallel on a respective carrier associated with FR2 in NR and with at least one of: FR1 in LTE or NR, or cell search, will be performed on a respective carrier associated with at least one of: FR1 or LTE that is searched before the corresponding carrier in FR 2; and performing a cell search based on the determined pattern.

In a second aspect, a second device is provided. The second device includes at least one processor; at least one memory including computer program code; the at least one memory stores instructions that, when executed by the at least one processor, cause the second device to at least generate an indication of a pattern to be used for cell search performed by the first device, the pattern at least indicating: the cell search will be performed in parallel on the respective carriers associated with FR2 in NR and with at least one of: FR1 in LTE or NR, or cell search, will be performed on a respective carrier associated with at least one of: FR1 or LTE that is searched before the corresponding carrier in FR 2; and sending the indication to the first device.

In a third aspect, a method is provided. The method includes determining a pattern for cell search that indicates at least that cell search is to be performed in parallel on a respective carrier associated with FR2 in NR and with at least one of: FR1 in LTE or NR, or cell search, will be performed on a respective carrier associated with at least one of: FR1 or LTE that is searched before the corresponding carrier in FR 2; and performing a cell search based on the determined pattern.

In a fourth aspect, a method is provided. The method comprises generating an indication of a pattern to be used for cell search performed by the first device, the pattern at least indicating: the cell search will be performed in parallel on the respective carriers associated with FR2 in NR and with at least one of: FR1 in LTE or NR, or cell search, will be performed on a respective carrier associated with at least one of: FR1 or LTE that is searched before the corresponding carrier in FR 2; and sending the indication to the first device.

In a fifth aspect, there is provided an apparatus comprising means for determining a pattern for cell search, the pattern indicating at least that cell search is to be performed in parallel on a respective carrier associated with FR2 in NR and with at least one of: FR1 in LTE or NR, or cell search, will be performed on a respective carrier associated with at least one of: FR1 or LTE that is searched before the corresponding carrier in FR 2; and means for performing a cell search based on the determined pattern.

In a sixth aspect, there is provided an apparatus comprising means for generating an indication of a pattern to be used for cell search performed by a first device, the pattern indicating at least: the cell search will be performed in parallel on the respective carriers associated with FR2 in NR and with at least one of: FR1 in LTE or NR, or cell search, will be performed on a respective carrier associated with at least one of: FR1 or LTE that is searched before the corresponding carrier in FR 2; and means for sending the indication to the first device.

In a seventh aspect, there is provided a computer readable medium having a computer program stored thereon, which, when executed by at least one processor of a device, causes the device to perform the method according to the third or fourth aspect.

Other features and advantages of embodiments of the present disclosure will be apparent from the following description of the particular embodiments, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the embodiments of the disclosure.

Drawings

Embodiments of the present disclosure are presented in an exemplary sense and their advantages are explained in more detail below with reference to the drawings, in which

FIG. 1 illustrates an example environment in which example embodiments of the present disclosure may be implemented;

fig. 2 shows a signaling diagram illustrating a procedure of a serving cell search according to some example embodiments of the present disclosure;

fig. 3 illustrates a flowchart of an example method of serving cell search, according to some example embodiments of the present disclosure;

fig. 4 illustrates a flowchart of an example method of serving cell search, according to some example embodiments of the present disclosure;

FIG. 5 illustrates a simplified block diagram of a device suitable for implementing exemplary embodiments of the present disclosure; and

fig. 6 illustrates a block diagram of an example computer-readable medium, according to some embodiments of the disclosure.

In the drawings, the same or similar reference numerals denote the same or similar elements.

Detailed Description

Principles of the present disclosure will now be described with reference to some example embodiments. It should be understood that these examples are presented for illustrative purposes only and to assist those skilled in the art in understanding and practicing the present disclosure and are not intended to suggest any limitation as to the scope of the present disclosure. The disclosure described herein may be implemented in various ways other than those described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

References in the present disclosure to "one embodiment," "an example embodiment," etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with an example embodiment, it is submitted that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It will be understood that, although the terms "first" and "second," etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish between the functionality of the various elements. As used herein, the term "and/or" includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," and/or "including," when used herein, specify the presence of stated features, elements, components, and/or so forth, but do not preclude the presence or addition of one or more other features, elements, components, and/or groups thereof.

As used in this application, the term "circuitry" may refer to one or more or all of the following:

(a) Pure hardware circuit implementations (such as implementations in analog and/or digital circuitry only), and

(b) A combination of hardware circuitry and software, such as (if applicable):

(i) Combination of analog and/or digital hardware circuit(s) and software/firmware, and

(ii) Any portion of the hardware processor(s) with software, including the digital signal processor(s), software, and memory(s) that work together to cause a device such as a mobile phone or server to perform various functions, and

(c) Hardware circuit(s) and/or processor(s) such as microprocessor(s) or portion of microprocessor(s) that require software (e.g., firmware) to run, but the software may not exist when it is not needed for operation.

This definition of circuitry applies to all uses of this term in this application, including all uses in any claims. As a further example, as used in this application, the term circuitry also encompasses hardware-only circuitry or a processor (or multiple processors) or a portion of hardware circuitry or a processor and its (or their) implementation in conjunction with software and/or firmware. For example and where applicable to the elements of the specific claims, the term circuitry also encompasses a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, a cellular network device, or other computing or network device.

As used herein, the term "communication network" refers to a network that conforms to any suitable communication standard, such as a fifth generation (5G) system, long Term Evolution (LTE), LTE-advanced (LTE-a), wideband Code Division Multiple Access (WCDMA), high Speed Packet Access (HSPA), narrowband internet of things (NB-IoT), and so forth. Furthermore, the communication between the terminal device and the network device may be performed in the communication network according to any suitable generational communication protocol, including, but not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, future fifth generation (5G) New Radio (NR) communication protocols and/or any other protocol currently known or to be developed in the future. Embodiments of the present disclosure may be applied to various communication systems. In view of the rapid development of communications, there will of course also be future types of communication technologies and systems that may embody the present disclosure. The scope of the present disclosure should not be considered limited to only the systems described above.

As used herein, the term "network device" refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. A network device may refer to a Base Station (BS) or an Access Point (AP), such as a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), a NR next generation NodeB (gNB), a Remote Radio Unit (RRU), a Radio Head (RH), a Remote Radio Head (RRH), a relay, a low power node (such as femto, pico, etc.), depending on the terminology and technology applied. The RAN split architecture includes a gNB-CU (centralized unit, hosting RRC, SDAP, and PDCP) that controls multiple gNB-DUs (distributed units, hosting RLC, MAC, and PHY). The relay node may correspond to the DU portion of the IAB node.

The term "terminal device" refers to any terminal device that may be capable of wireless communication. By way of example, and not limitation, a terminal device may also be referred to as a communication device, user Equipment (UE), subscriber Station (SS), portable subscriber station, mobile Station (MS), or Access Terminal (AT). The terminal devices may include, but are not limited to, mobile phones, cellular phones, smart phones, voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, personal Digital Assistants (PDAs)), portable computers, desktop computers, image capture terminal devices (such as digital cameras), gaming terminal devices, music storage and playback devices, in-vehicle wireless terminal devices, wireless terminals, mobile stations, laptop embedded devices (LEEs), laptop mounted devices (LMEs), USB dongles, smart devices, wireless Customer Premises Equipment (CPE), internet of things (IoT) devices, watches or other wearable devices, head Mounted Displays (HMDs), vehicles, drones, medical devices and applications (e.g., tele-surgery), industrial devices and applications (e.g., robots and/or other wireless devices operating in an industrial and/or automated processing chain environment), consumer electronic devices, devices operating in a commercial and/or industrial wireless network, and the like. The terminal device may also correspond to a Mobile Terminal (MT) part of an Integrated Access and Backhaul (IAB) node (also known as a relay node). In the following description, the terms "terminal device", "communication device", "terminal", "user equipment" and "UE" may be used interchangeably.

Although in various example embodiments, the functionality described herein may be performed in a fixed and/or wireless network node, in other example embodiments, the functionality may be implemented in a user equipment device, such as a cell phone or tablet or notebook or desktop or mobile internet of things device or a fixed internet of things device. The user equipment device may for example be equipped with appropriate corresponding capabilities as described in connection with the fixed and/or wireless network node(s). The user equipment device may be a user equipment and/or a control device such as a chipset or processor configured to control the user equipment when installed in the user equipment. Examples of such functionality include a bootstrapping server function and/or a home subscriber server, which may be implemented in a user equipment device by providing the user equipment device with software configured to cause the user equipment device to execute from the perspective of these functions/nodes.

Fig. 1 illustrates an example communication network 100 in which embodiments of the present disclosure may be implemented. As shown in fig. 1, the communication network 100 may include a terminal device 110 (hereinafter may also be referred to as UE 110 or first device 110). The communication network 100 may also include a network device 120 (hereinafter may also be referred to as a gNB 120 or a second device 120). Terminal device 110 and network device 120 may communicate with each other.

It will be appreciated that the number of network devices and terminal devices shown in fig. 1 is given for illustrative purposes and is not meant to suggest any limitation. Communication network 100 may include any suitable number of network devices and terminal devices.

Currently, the UE may measure synchronization signal-reference signal received power (SS-RSRP) and secondary synchronization signal-reference signal received quality (SS-RSRQ) levels of the serving cell and evaluate a cell selection criterion for the serving cell at least once every M1 x N1 Discontinuous Reception (DRX) cycle; wherein m1=2 if SSB-based measurement timing configuration (SMTC) periodicity (TSMTC) >20ms and DRX cycle is less than or equal to 0.64 seconds, otherwise m1=1.

The UE may use at least 2 measurements to filter SS-RSRP and SS-RSRQ measurements of the serving cell. Within the set of measurements for filtering, at least two measurements may be separated by at least a DRX cycle/2.

If the UE is in N _serv The serving cell evaluated (according to table 1 below) in the individual continuous DRX cycles does not meet the cell selection criteria, the UE may initiate measurements of all neighboring cells indicated by the serving cell. If the UE in Radio Resource Control (RRC) idle mode fails to find any new suitable cell within 10s based on searches and measurements using intra-frequency, inter-frequency and inter-RAT information indicated in the system information, the UE may initiate a cell selection procedure for the selected Public Land Mobile Network (PLMN).

Table 1: n (N) _serv Definition of (2)

However, conventional mechanisms for cell search may not allow the UE to have reasonable search time in all cases. For example, the UE may be configured to have one or more NR inter-frequency carriers of FR1 and FR2 to be measured in idle mode. In this case, a minimum of up to 14 carriers, including the serving carrier, need to be measured. For NR, the number of layers may be up to 7 and may consist of FR1 and/or FR2 carriers.

The expected search time for the UE to detect potential cells on the carrier depends on the Radio Access Technology (RAT) and for NR, the expected search time also depends on whether the carrier is in FR1 or FR2. In case the UE detects that the serving cell quality no longer meets the cell selection criteria, the UE may search for configured carriers without interruption, regardless of any rules restricting UE measurement activity.

In LTE, cell detection and measurement may be performed every 5ms, since reference signals associated with PSS, SSS and CRS are available at 5ms periodicity, for example.

In NR, since reference signals (PSS, SSS) are available with SSB periodicity or assumed to be available with each SMTC periodicity, cell detection and measurement may be performed at each SSB period (in ms), where SSB or SMTC periods may be configured by the network and have the following ranges: [5, 10, 20, 40, 80 and 160] ms.

To estimate the UE search time when defining the approximate maximum search time required to search all possible carriers when needed (in which case the serving cell quality no longer meets the cell selection criteria), the UE time for cell detection and the time for measurements on carriers after potential cell detection may be estimated and considered for all possible configured carriers (i.e. up to 14 carriers).

For LTE it is generally assumed that the UE should be able to detect available cells using 5 instances of PSS/SSS under the worst required conditions. A round of measurement is then required. That is, up to 5 measurements may be performed in connected mode (to account for worst conditions), while idle mode may only require 2 samples.

For NR, it is also assumed that up to 5 samples are required in FR1, and then one round of measurement is performed (5 and 2 samples are assumed in the connected mode and idle mode, respectively). For FR2, it is necessary to allow the UE to sweep through multiple Rx panels and spatial settings in time. How the UE implements the frequency sweep depends on the implementation of the UE. In the conventional manner, there are two methods, namely, using a connection mode requirement based on unused DRX or using recalculated idle mode performance, not applying DRX, but configuring SMTC periods based on measured carriers.

For example, if the connection mode requirement is considered to be the baseline, it is assumed that 5 are usedPSS/SSS samples are used for cell detection and 5 samples are also needed for one round of measurement, then the search time for 5 instances of PSS/sss+5 CRS measurements for LTE may be equal to 5×5ms+5×5ms+margin=100 ms (note that margin is optional). In this case, the search time of NR FR1 may be equal to (T _{PSS/SSS_sync_intra} +T _{SSB_measurement_period_intra} )＝max(600ms,ceil(5x K _p ) x SMTC period) ^{Comment 1} x CSSF _intra +max(200ms,ceil(5x K _p ) x SMTC period) ^{Comment 1} x CSSF _intra =max (600 ms,5x SMTC period) +max (200 ms,5x SMTC period) (DRX is not used) = (25 ms-800 ms) + (25-800) = [ 50); 1600ms]Wherein smtc= [5, 10, 20, 40, 80 and 160]ms, and no margin is applied (assuming the UE uses SMTC of the carrier and is not limited by any rules that limit UE measurements (including DRX)).

Also in this case, the search time for NR FR2 may be equal to (T _{PSS/SSS_sync_intra} +T _{SSB_measurement_period_intra} )＝(max(600ms,ceil(M _{pss/sss_sync_w/o_gaps} x K _p x K _{layer1_measurement} ) x SMTC period) ^{Comment 1} x CSSF _intra )+(max(400ms,ceil(M _{meas_period_w/o_gaps} x K _p x K _{layer1_measurement} ) x SMTC period) ^{Comment 1} x CSSF _intra )＝(max(600ms,M _{pss/sss_sync_w/o_gaps} x SMTC period)), + (max (400 ms, m) _{meas_period_w/o_gaps} x SMTC period)), = (120-3840) ms+ (120-3840) ms=240-7680 ms, wherein SMTC = [5, 10, 20, 40, 80, and 160]ms, and no application margin (assuming the UE uses SMTC of the carrier and is not limited by any rules restricting UE measurements (including DRX)), M _{pss/sss_sync_w/o_gaps} ＝M _{meas_period_w/o_gaps} ＝24。

That is, in connected mode, the total search and measurement time for each NR FR1 carrier will be 50ms-1600ms, while the total search and measurement time for each NR FR2 carrier is: 240ms-7680ms due to the requirement of "no matter what any rules restrict UE measurement activity".

Furthermore, if the idle mode requirement is considered asBaseline, where NR cell detection requires X samples of LTE and 36 samples of PSS/SSS for cell detection, and one round of measurement requires Y samples of LTE and 4 samples of NR, the search time for 5 instances of PSS/sss+2 CRS measurements for LTE may be equal to x×5ms+y×5ms+margin=70 ms (where addition of margin is optional). In this case, the search time for NR FR1 may be equal to (T _{PSS/SSS_sync_intra} +T _{SSB_measurement_period_intra} ) =36 x SMTC period+4 x SMTC period=200 ms-6400ms, while the search time for NR FR2 may be equal to (T _{PSS/SSS_sync_intra} +T _{SSB_measurement_period_intra} ) =36x 8x SMTC period+4x 8x SMTC period=1600 ms-51200ms, where it is assumed that the UE is allowed to search each carrier in a serial fashion, for the worst case with a connection mode assumption, 7NR FR2 carriers+7 LTE carriers (including services) may need up to 54460ms, and for the lowest case with an idle mode assumption, 7NR FR2 carriers+7 LTE carriers (including services) may need up to 358890ms. Even assuming each FR search, the maximum search time based on the minimum requirement of the UE is limited by the FR2 search time (53760 ms-358400 ms).

That is, under the requirement of the conventional UE for cell search, when the minimum requirement of the UE is assumed, the search time of the UE required for cell search may exceed a threshold time interval, for example, 10s.

It should be appreciated that in these examples as described above, it is assumed that intra-frequency requirements are used as baselines. However, the solutions in the present disclosure are not limited to being based on intra-frequency measurement requirements, and may also be based on inter-frequency measurement requirements or inter-RAT measurement requirements, for example.

Accordingly, the present disclosure provides a solution for serving cell search. In this solution, the UE may determine a mode for cell search. The mode may instruct the UE to search for carriers associated with LTE and/or FR1 and FR2 in parallel, or to search for carriers associated with LTE or FR1 before carriers associated with FR 2. The UE may then perform a cell search based on the determined mode.

In this way, the method proposed in the present disclosure may allow the UE time to perform cell search considering the maximum number of configured carriers without having to lengthen the allowed search time, and thus may avoid unnecessarily long UE delays.

The principles and implementations of the present disclosure will be described in detail below with reference to fig. 2, which shows a signaling diagram of a process 200 of serving cell search according to some example embodiments of the present disclosure. For discussion purposes, the process 200 will be described with reference to fig. 1. Process 200 may involve UE 110 and gNB 120.

For example, procedure 200 may be implemented if UE 110 is not allowed to apply DRX in idle mode when performing a cell search because the serving cell no longer satisfies the cell selection criteria.

Reference is now made to fig. 2. As shown, if a cell search is triggered at UE 110, UE 110 may determine (210) a mode of the cell search. Alternatively, the pattern may indicate that cell search may be performed in parallel on carriers associated with LTE and/or FR1 and FR 2. As another option, the pattern may indicate that the cell search may be performed on a carrier associated with LTE or FR1 before a carrier associated with FR 2.

In some example embodiments, UE 110 may autonomously determine a mode for cell search. For example, if UE 110 is in a situation where the quality of the serving cell is low, cell search may be performed in parallel on carriers associated with LTE and/or FR1 and FR2, or on carriers associated with LTE or FR1 before cell search is performed on carriers associated with FR2, to ensure fast cell search.

Alternatively or additionally, the gNB 120 may determine which mode the UE 110 is to use to perform the cell search. The gNB 120 may generate an indication of the determined mode and send (205) the mode to the UE 110.

After determining the mode for cell search, UE 110 may perform 215 a cell search based on the determined mode.

Embodiments of cell search based on different mode UEs may be described in detail as follows. The worst case scenario is assumed and there is no restriction/assumption on how the network configures SMTC on the configured carriers, and it is assumed that the UE only needs to search for 1 carrier at a time. As described above, the total time may be up to 358400ms under idle mode assumption and up to 53760ms under connected mode assumption, where 160ms SMTC periods and 7 FR2 carriers are assumed. Then, LTE searches may also be required, which may be up to 7 x 70-100 ms, and in addition, which together accumulate a significant total search time.

In general, in the worst case, an overall search may be allowed. Specifically, assuming that the UE is configured with X NR carriers, where Y carriers are FR1 carriers, for the connected mode assumption, the NR search time may be equal to (y×1600 ms+ (X-Y) ×7680 ms), and the LTE search time may be equal to (14-X) ×70-100 ms. For idle mode, the search time may be determined in the same manner but using different absolute numbers.

In the case where the UE searches for the largest worst case configuration of 7 NR carriers (FR 1 or FR 2) and 7 LTE carriers without limitation, the UE's requirement for search time may be expressed as search time=max (10 seconds, 700ms+ (y×1600 ms+ (X-Y) ×7680 ms)), where X is the number of configured NR carriers, where Y NR carriers are FR1 carriers.

If the actually configured SMTC period of the configured NR carrier may be less relaxed, the allowed search time may be expressed as search time=max (10 seconds, T _{LTE_carrier_search} ++ (Y [10] SMTC period]ms+ (X-Y) [ 48X smtc period ]]ms), where X is the number of configured NR carriers, where Y NR carriers are FR1 carriers, and SMTC is the network configuration SMTC for each NR carrier to be searched. Here, 5 samples for cell detection and 5 samples for measurement of NR FR1 carrier are assumed, and 24 samples for cell detection and 24 samples for measurement of NR FR2 carrier are assumed.

Under normal conditions, the search time may be expressed as search time=max (10 seconds, (T _{LTE_carrier_search} +T _{NR_FR1_carrier_search} +T _{NR_FR2_carrier_search} ) (x) wherein T _{LTE_carrier_search} Time allowed to search LTE carrier, T _{NR_FR1_carrier_search} ＝Y*[[10]* SMTC period]ms,T _{NR_FR2_carrier_search} ＝(X-Y)*[[48]* SMTC period]ms; and X is the number of configured NR carriers, where Y NR carriers are FR1 carriers and SMTC is the network configured SMTC for each carrier to be searched.

It should be appreciated that the numbers/parameters [10] and [48] used herein may be considered as one example, which may depend on the expected UE requirements for the search time and what mode (connected mode/idle mode) is considered as the baseline UE requirement. Any other suitable value may be used.

If UE 110 performs cell search on carriers associated with LTE and/or FR1 and FR2 in parallel, the search time may be expressed as, as an alternative, assuming that the current minimum required time for cell search for a predefined time interval (e.g., 10 seconds) remains unchanged:

search time=max [ (10, max (10,1400 + (Y [ [10 ]) ]]* SMTC period]ms)),Max(10,(X-Y)*[[48]* SMTC period]ms))]＝Max[10,(T _{LTE_carrier_search} +T _{NR_FR1_carrier_search} ),T _{NR_FR2_carrier_search} )] (1)

Where X is the number of configured NR carriers, where Y NR carriers are FR1 carriers, SMTC is a network configured SMTC for each carrier to be searched, and 1400ms is an example of the time allowed by the search time assumption of LTE carriers.

As another option, if it can be assumed that a fixed time interval (e.g., 10 seconds) includes searching for an LTE carrier, when NR cannot be searched for due to SMTC limitation (SSB broadcasting), the search time can be expressed as:

search time = Max [10, t _{NR_FR1_carrier_search} ],Max(10,T _{NR_FR2_carrier_search} )] (2)

It may also be assumed that a fixed time interval (e.g., 10 seconds) includes a search for LTE carriers and NR FR1, as searching for LTE carriers and NR FR1 carriers within a fixed time interval may be allowed. In this case, the search time can be expressed as:

search time = Max [10, t _{NR_FR2_carrier_search} ] (3)

It should be appreciated that the fixed lower boundary may also be removed in some cases.

In some example embodiments, in the case where UE 110 performs cell search on carriers associated with LTE and/or FR1 and FR2 in parallel, cell search may be stopped when UE 110 detects a suitable cell. In this case, the lower boundary of the search unit may be removed. The search time can be expressed as:

search time=min [ (700+ (Y [ [10 ])]* SMTC period]ms)),((X-Y)*[[48]* SMTC period]ms)]＝Min[(T _{LTE_carrier_search} +T _{NR_FR1_carrier_search} ),T _{NR_FR2_carrier_search} ] (4)

Where X is the number of configured NR carriers, where Y NR carriers are FR1 carriers, SMTC is the network configured SMTC for each carrier to be searched.

Alternatively, a new maximum search time may be defined based on SMTC assumptions, with at least one carrier for 20ms per band and the remaining carriers for 160ms. In this case, UE 110 may search only for the one carrier in each frequency band. The search time can be expressed as:

search time=max [ (700+ (X1) [ [10 ]]* SMTC period]ms)),(Y1*[[48]* SMTC period]ms)]＝Max[(T _{LTE_carrier_search} +T _{NR_FR1_carrier_search} ),T _{NR_FR2_carrier_search} ] (5)

Where X1 is the number of configured NR FR1 carriers, Y1 is the number of NR FR2 carriers having smtc=20 ms configuration per FR2 band; SMTC is a network configured SMTC in each FR1 and FR2 carrier to be searched and the FR2 carrier searched by the UE is 20ms SMTC. Thus, in one example, the UE searches all configured LTE and NR FR1 carriers and all NR FR2 carriers with smtc=20 ms. In one example, the UE need only search for one FR2 carrier per band, and in one example, the carrier may be limited to the carrier with smtc=20 ms or the carrier with the shortest SMTC period.

In this case, the UE allows additional time for FR2 search only if no FR1 candidate is detected.

In the case where UE 110 performs a cell search on carriers associated with LTE and/or FR1 before performing a cell search on those carriers associated with FR2, if UE 110 measures carriers configured by LTE and NR FR1, UE 110 may perform the cell search at predetermined time intervals (e.g., 10 s). If UE 110 is configured with an NR FR2 carrier, UE 110 may have additional search time allowed if the time required to search for the NR FR1 carrier exceeds a predefined time interval. In this case, the search time can be expressed as:

search time = Min [10, max [ (T) _{LTE_carrier_search} +T _{NR_FR1_carrier_search} )],T _{NR_FR2_carrier_search} ] (6)

As another option, UE 110 may initially search for LTE and/or NR FR1 carriers. If a suitable cell is detected, UE 110 may stop the cell search. That is, UE 110 may no longer search for NR FR2 carriers. In this case, the search time can be expressed as:

search time 1=10s; or (b)

Search time 2=search time 1+t _{NR_FR2_carrier_search} (7)

Alternatively, the search time may be expressed as:

search time = maximum (10 s, t _{NR_FR2_carrier_search} ) (8)

In this case, if a suitable cell is detected in LTE or NR FR1, UE 110 may stop further searching for configured carriers, including cell searching for configured NR FR2 carriers. If a suitable LTE/FR1 cell is searched, the search time may be equal to a predefined time interval (e.g. 10 s). If no suitable LTE/FR1 cell is searched, searching for FR2 cells is started, the search time may be equal to Max (10 s, T _{NR_FR2_carrier_search} )。

In some scenarios, it is also possible to configure only the carrier associated with FR 2. In this case, UE 110 may be allowed additional extended search time for cell search. Such an extended search time may depend on, for example, the number of configured FR2 carriers, FR2 carriers having an SMTC period of 20ms in each band (or all carriers), FR2 subcarriers having a minimum SMTC period (period) in each or all bands.

In this way, the method proposed in the present disclosure may allow the UE time to perform cell search considering the maximum configured number of carriers without having to lengthen the allowed search time, and thus may avoid unnecessary long delays of the UE.

Fig. 3 illustrates a flowchart of an example method 300 of serving cell search, according to some example embodiments of the present disclosure. The method 300 may be implemented at the first device 110, as shown in fig. 1. For discussion purposes, the method 300 will be described with reference to FIG. 1.

At 310, the first device determines a pattern for cell search that indicates at least that cell search is to be performed in parallel on a respective carrier associated with FR2 in NR and with at least one of: FR1 in LTE or NR, or cell search, will be performed on a respective carrier associated with at least one of: FR1 or LTE that is searched before the corresponding carrier in FR 2; and performing a cell search based on the determined pattern.

In some example embodiments, the first device may autonomously determine the mode by the first device; or determining the mode based on an indication of the mode to be used for cell search received from the second device.

At 320, the first device performs a cell search based on the determined mode.

In some example embodiments, if it is determined that the cell search is to be performed in parallel on a respective carrier associated with the second frequency range in the NR and with at least one of the LTE or the first frequency range, the first device performs the cell search within at least one of: a predefined time interval, a time interval for searching for a respective carrier associated with at least one of: LTE or FR1, or a time interval for searching for a corresponding carrier associated with FR 2.

In some example embodiments, the first device may stop cell search when satisfactory cells are detected if it is determined that the cell search is to be performed in parallel on a respective carrier associated with the second frequency range in the NR and with at least one of the LTE or the first frequency range.

In some example embodiments, if it is determined that the cell search is to be performed on a respective carrier associated with at least one of the first frequency range or the LTE preceding the second frequency range, the first device performs the cell search on a respective carrier associated with at least one of the LTE or the first frequency range for a predefined time interval.

In some example embodiments, the first device may stop the cell search if a satisfactory cell is detected.

In some example embodiments, if it is determined that a satisfactory cell is not detected, the first device performs the cell search on a respective carrier associated with the second frequency range for a time interval for searching the respective carrier associated with the second frequency range.

In some example embodiments, if it is determined that carriers associated with the LTE and the first frequency range are not configured, the first device performs the cell search for a time interval required for the cell search on the corresponding carrier on the second frequency range.

In some example embodiments, the first device comprises a terminal device and the second device comprises a network device.

Fig. 4 illustrates a flowchart of an example method 400 of serving cell search, according to some example embodiments of the present disclosure. The method 400 may be implemented at the second device 120, as shown in fig. 1. For discussion purposes, the method 400 will be described with reference to FIG. 1.

At 410, the second device generates an indication of a mode to be used for cell search performed by the first device, the cell search to be performed in parallel on a respective carrier associated with FR2 in NR and with at least one of: FR1 in LTE or NR, or cell search, will be performed on a respective carrier associated with at least one of: FR1 or LTE that is searched before the corresponding carrier in FR 2; and performing a cell search based on the determined pattern.

At 420, the second device sends the indication to the first device.

In some example embodiments, an apparatus capable of performing the method 300 (e.g., implemented at the UE 110) may include means for performing the various steps of the method 300. The apparatus may be implemented in any suitable form. For example, the apparatus may be implemented in a circuit or a software module.

In some example embodiments, the apparatus includes means for determining a pattern for cell search that indicates at least that cell search is to be performed in parallel on a respective carrier associated with FR2 in NR and with at least one of: FR1 in LTE or NR, or cell search, will be performed on a respective carrier associated with at least one of: FR1 or LTE that is searched before the corresponding carrier in FR 2; and performing a cell search based on the determined pattern.

In some example embodiments, an apparatus capable of performing the method 400 (e.g., implemented at the gNB 120) may include means for performing the various steps of the method 400. The apparatus may be implemented in any suitable form. For example, the apparatus may be implemented in a circuit or a software module.

In some example embodiments, the apparatus includes means for generating an indication of a pattern to be used for cell search performed by the first device, the pattern at least indicating: the cell search will be performed in parallel on the respective carriers associated with FR2 in NR and with at least one of: FR1 in LTE or NR, or cell search, will be performed on a respective carrier associated with at least one of: FR1 or LTE that is searched before the corresponding carrier in FR 2; and means for sending the indication to the first device.

Fig. 5 is a simplified block diagram of an apparatus 500 suitable for implementing embodiments of the present disclosure. Device 500 may be provided to implement a communication device, such as UE 110 and gNB 120 as shown in fig. 1. As shown, the device 500 includes one or more processors 510, one or more memories 520 coupled to the processors 510, and one or more communication modules 540 coupled to the processors 510.

The communication module 540 is used for two-way communication. The communication module 540 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interface may represent any interface necessary to communicate with other network elements. In some example embodiments, the communication module 540 may include at least one antenna.

Processor 510 may be of any type suitable for use in a local technology network and may include, by way of non-limiting example, one or more of a general purpose computer, a special purpose computer, a microprocessor, a Digital Signal Processor (DSP), and a processor based on a multi-core processor architecture. The device 500 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to the clock of the synchronous master processor.

Memory 520 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memory include, but are not limited to, read-only memory (ROM) 524, electrically programmable read-only memory (EPROM), flash memory, hard disks, compact Disks (CD), digital Video Disks (DVD), and other magnetic and/or optical storage. Examples of volatile memory include, but are not limited to, random Access Memory (RAM) 522 and other volatile memory that will not last for the duration of the power outage.

The computer program 530 includes computer-executable instructions that are executed by an associated processor 510. Program 530 may be stored in ROM 520. Processor 510 may perform any suitable actions and processes by loading program 530 into RAM 520.

Embodiments of the present disclosure may be implemented by means of program 530 such that device 500 may perform any of the processes of the present disclosure as discussed with reference to fig. 2-4. Embodiments of the present disclosure may also be implemented in hardware or a combination of hardware and software.

In some embodiments, program 530 may be tangibly embodied in a computer-readable medium that may be included in device 500 (such as in memory 520) or other storage device accessible to device 500. Device 500 may load program 530 from a computer readable medium into RAM 522 for execution. The computer readable medium may include any type of tangible, non-volatile memory, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. Fig. 6 shows an example of a computer readable medium 600 in the form of a CD or DVD. The computer readable medium has a program 530 stored thereon.

In general, the various embodiments of the disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. 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. While various aspects of the embodiments of the disclosure are 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.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product comprises computer executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor to perform the methods 300 and 400 as described above with reference to fig. 3-4. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. In various embodiments, the functionality of the program modules may be combined or split between program modules as desired. Machine-executable instructions for program modules may be executed within a local device or within a distributed device. In distributed devices, program modules may be located in both local and remote memory storage media.

Program code for carrying out the methods of the present disclosure may be written in any combination of one or more programming languages. These program code may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus such that the program code, when executed by the processor or controller, causes the functions/operations specified in the flowchart and/or block diagram to be implemented. The program code may execute entirely on the machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of this disclosure, computer program code or related data may be carried by any suitable carrier to enable an apparatus, device, or processor to perform the various processes and operations described above. Examples of carriers include signals, computer readable media, and the like.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. The computer readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Moreover, although operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In some cases, multitasking and parallel processing may be advantageous. Also, while the above discussion contains several specific implementation details, these should not be construed as limitations on the scope of the disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination.

Although the disclosure has been described in language specific to structural features and/or methodological acts, it is to be understood that the disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. A first device, comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the first device to at least:

determining a pattern for cell search, the pattern indicating at least:

the cell search is to be performed in parallel on a respective carrier associated with a second frequency range in the new radio NR and with at least one of: a first frequency range in long term evolution, LTE, or said NR, or

The cell search is to be performed on a respective carrier associated with at least one of: the first frequency range preceding a corresponding carrier in the second frequency range, or the LTE; and

the cell search is performed based on the determined mode.

2. The first device of claim 1, wherein the first device is caused to determine the mode by:

Autonomously determining, by the first device, the mode; or (b)

The mode is determined based on an indication of the mode to be used for the cell search received from a second device.

3. The first device of claim 1, wherein the first device is caused to perform the cell search by:

if it is determined that the cell search is to be performed in parallel on a respective carrier associated with the second frequency range in the NR and with at least one of the LTE or the first frequency range, performing the cell search within at least one of:

the time period of the pre-defined time period,

a time interval for searching for a respective carrier associated with at least one of the LTE or the first frequency range, or

A time interval for searching for a respective carrier associated with the second frequency range.

4. The first device of claim 1, wherein the first device is caused to perform the cell search by:

if it is determined that the cell search is to be performed in parallel on a respective carrier associated with the second frequency range in the NR and with at least one of the LTE or the first frequency range, the cell search is stopped when a satisfactory cell is detected.

5. The first device of claim 1, wherein the first device is caused to perform the cell search by:

if it is determined that the cell search is to be performed on a respective carrier associated with at least one of the first frequency range or the LTE preceding the second frequency range, the cell search is performed on a respective carrier associated with at least one of the LTE or the first frequency range for a predefined time interval.

6. The first device of claim 5, wherein the first device is further caused to:

if it is determined that a satisfactory cell is detected, cell search is stopped.

7. The first device of claim 5, wherein the first device is further caused to:

if it is determined that a satisfactory cell is not detected, the cell search is performed on a respective carrier associated with the second frequency range for a time interval for searching the respective carrier associated with the second frequency range.

8. The first device of claim 1, wherein the first device is caused to perform the cell search by:

if it is determined that carriers associated with the LTE and the first frequency range are not configured, the cell search is performed within a time interval required for the cell search on the corresponding carrier on the second frequency range.

9. The first device of any of claims 1-8, wherein the first device comprises a terminal device and the second device comprises a network device.

10. A second device, comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the second device to at least:

generating an indication of a pattern to be used for cell search performed by the first device, the pattern at least indicating:

The cell search is to be performed on a respective carrier associated with at least one of the first frequency range or the LTE preceding a respective carrier in the second frequency range; and

the indication is sent to the first device.

11. The second device of claim 10, wherein the first device comprises a terminal device and the second device comprises a network device.

12. A method, comprising:

Determining, at a first device, a mode for cell search, the mode indicating at least:

The cell search is to be performed on a respective carrier associated with at least one of: the first frequency range or the LTE preceding a corresponding carrier in the second frequency range; and

the cell search is performed based on the determined mode.

13. The method of claim 12, wherein determining the pattern comprises:

receiving an indication of the mode to be used for the cell search from a second device; and

the mode is determined based on the indication.

14. The method of claim 12, wherein performing the cell search comprises:

The time period of the pre-defined time period,

15. The method of claim 12, wherein performing the cell search comprises:

if it is determined that the cell search is to be performed in parallel on a respective carrier associated with the second frequency range in the NR and with at least one of the LTE or the first frequency range: the cell search is stopped when a satisfactory cell is detected.

16. The method of claim 12, wherein performing the cell search comprises:

17. The method of claim 16, further comprising:

18. The method of claim 16, further comprising:

19. The method of claim 12, wherein performing the cell search comprises:

20. The method of any of claims 12-19, wherein the first device comprises a terminal device and the second device comprises a network device.

21. A method, comprising:

generating, at the second device, an indication of a pattern to be used for cell search performed by the first device, the pattern indicating at least:

The cell search is to be performed on a respective carrier associated with at least one of the first frequency range preceding a respective carrier in the second frequency range, or the LTE; and

the indication is sent to the first device.

22. The method of claim 21, wherein the first device comprises a terminal device and the second device comprises a network device.

23. An apparatus comprising means for performing at least the method of any one of claims 12-20 or the method of any one of claims 21-22.

24. A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method of any one of claims 12-20 or the method of any one of claims 21-22.