Patent Description:
A User equipment (UE) may be present in a <NUM>th Generation (<NUM>) and <NUM>th Generation (<NUM>) overlapping area, wherein in a Non-Stand Alone (NSA) device, Long Term Evolution (LTE) cells may be connected with a 5GCore (5GC) which may be referred to as Architecture option <NUM> per 3GPP connectivity standards. For <NUM> Stand Alone (SA) gNodeB (gNB) is directly connected to 5GC network which may be referred to as Architecture option <NUM> per 3GPP connectivity standards.

<CIT> discloses a method for handling cell selection in a multiple radio access technology dual connectivity (MR-DC) system, including scanning, by a user equipment (UE), at least one frequency, identifying, by the UE, a first cell supporting an MR-DC based on the scanned at least one frequency, and camping, by the UE, to the identified first cell.

In a discussion paper to <NPL>, the issue of inefficient cell selection and reselection in the case of different SSB periodicities set on different cells and frequency layers was discussed in general.

When the UE is powered on or when the UE is recovering from out of service (OOS), or when higher priority scan is triggered, the device takes a long time to camp on best available cell as there is a delay in finding the cell for camping.

<FIG> illustrates a conventional method of camping on a cell when the UE is in powered on state or out of service (OOS) recovery state. As seen in <FIG> at <NUM> the UE is powered on or is recovering from OOS mode. At <NUM>, <NUM> MRU (most recently used) frequencies are scanning for finding the cell. At, <NUM> the method includes determining whether the cell is found or not. At <NUM>, the UE is camped on the <NUM> cell if the <NUM> cell is found. At <NUM>, if the cell is not found then the method comprises performing scan on the <NUM> MRU frequencies. At <NUM>, the method includes determining whether the cell for camping the UE is found after scanning the <NUM> MRU frequencies. The UE is camped on the <NUM> cell with 5GC at <NUM> if the cell is found. If the cell is not found at <NUM>, then a <NUM> full band scan is performed at <NUM> followed by a <NUM> full band scan at full band scan at <NUM> if no cell is found at <NUM> after performing the <NUM> full band scan.

As discussed above scanning the <NUM> full band and if the cell is not found then scanning the <NUM> full band causes a delay and increases latency.

<FIG> illustrates a conventional method of camping the UE when the UE is in connected mode. As seen in <FIG>, at <NUM> the UE is connected to <NUM>. At <NUM> a higher priority PLMN (public land mobile network) search is performed. At <NUM>, the method includes determining whether the UE is connected in <NUM> mode. At <NUM>, the <NUM> full band scan is performed in background if the UE is connected to <NUM> stack, followed by <NUM> MRU scan and <NUM> full band scan at <NUM>. If the UE is not connected to <NUM>, then the <NUM> full band scan is performed in foreground at <NUM> followed by <NUM> MRU and <NUM> full band scan at <NUM>. At <NUM>, the PLMN is reported to upper layers. This causes a delay in reporting the PLMN to upper layers.

Embodiments of the disclosure provide a method and system for camping the UE on a cell in <NUM> and <NUM> overlapping area without delay.

Embodiments of the disclosure improve latency in searching and reporting higher priority PLMN to upper layers during Higher Priority PLMN search.

Embodiments of the disclosure provide a method and system to camp the UE on the best available state when the UE is powered on or is recovering from OOS mode.

Embodiments of the disclosure prepare a combined MRU list for reducing the latency of finding the cell.

Embodiments of the disclosure perform <NUM> scan in parallel to <NUM> scan.

Embodiments of the disclosure utilise transceiver sets available in <NUM> capable UE for reducing camping time of the UE.

Embodiments of the disclosure optimise stored frequency information for eLTE and <NUM> cells connected to <NUM> core network.

A method and apparatus are provided as set out in the independent claims.

Example embodiments herein disclose a method of camping a User Equipment (UE) on a cell, when the UE is present in overlapping area of <NUM>th Generation (<NUM>) Stand Alone (SA), <NUM> Non-SA, and Long Term Evolution LTE. The method comprises: creating a combined Most Recently Used (MRU) list by merging a list <NUM> MRU frequencies with a Public Land Mobile Network (PLMN) having a 5GC and a list of <NUM> MRU frequencies; determining whether one of a <NUM> cell with <NUM> core and a <NUM> cell is available for camping the UE by performing a MRU scan on the combined MRU list.

In an example embodiment, performing the MRU scan comprises performing a scan on the list of <NUM> MRU frequencies in parallel to a scan on the list of <NUM> MRU frequencies with 5GC.

In an example embodiment, the UE is camped on one of the <NUM> cell with <NUM> core and the <NUM> cell in response to determining that one of the <NUM> cell and the <NUM> cell with <NUM> core is available for camping the UE based on the MRU scan on the combined MRU list.

In an example embodiment, the UE performs a <NUM> MRU frequency scan on a list of <NUM> MRU frequencies without 5GC in response to determining that one of the <NUM> cell with <NUM> core and the <NUM> cell is not available for camping the UE based on the MRU scan on the combined MRU list, and camping the UE based on the <NUM> MRU frequency scan.

In an example embodiment, the UE determines whether a SIB24 message is present providing details about a NR radio. Based on the NR information being present the UE searches for neighboring <NUM> cell for camping the UE. If the NR information is not present, then the UE <NUM> is camped on the <NUM> cell without 5GC.

In an example embodiment, camping the UE based on the <NUM> MRU frequency scan comprises determining whether a <NUM> cell without 5GC is available for camping the UE by performing the <NUM> MRU frequency scan on the list of <NUM> MRU frequencies without 5GC. The camping based on the <NUM> MRU scan comprises camping the UE on the <NUM> cell without 5GC in response to determining that the <NUM> cell without 5GC is available for camping the UE based on the <NUM> MRU frequency scan on the list of <NUM> MRU frequencies without the 5GC. In an example embodiment, the UE performs a <NUM> full band scan on a list of <NUM> frequencies and a <NUM> full band scan on a list of <NUM> frequencies in parallel, and camping the UE based on the <NUM> full band scan or the <NUM> full band scan.

In an example embodiment camping the UE based on the <NUM> full band scan or the <NUM> full band scan comprises: determining whether at least one of a <NUM> cell is available based on the <NUM> full band scan on the list of <NUM> frequencies, or whether a <NUM> cell is available based on the <NUM> full band scan on the list of <NUM> frequencies. In an example embodiment, the UE is camped on the <NUM> cell and terminating the the <NUM> full band scan in response to determining that the <NUM> cell is available based on the <NUM> full band scan. While camping the UE on the <NUM> cells, <NUM> cell with <NUM> core are given higher priority over <NUM> cells without 5GC.

In an example embodiment The UE is camped on the <NUM> cell and the <NUM> full band scan is terminated in response to determining that that the <NUM> cell is available based on the <NUM> full band scan. In an example embodiment, the UE is camped on the <NUM> cell and the <NUM> full band scan is terminated in response to determining that both the <NUM> cell is available based on the <NUM> full band scan and the <NUM> cell is available based on the <NUM> full band scan.

In an example embodiment, based on the UE being camped on the <NUM> cell without 5GC, the UE determines whether the SIB24 message is present providing details about the NR radio. Based on the NR information being present the UE searches for neighboring <NUM> cell for camping the UE. Based on the NR information not being present, the UE <NUM> is camped on the <NUM> cell without 5GC.

Accordingly various embodiments herein disclose a method of camping the UE on the cell, based on the UE being in connected state. The method comprises: detecting, by the UE, a higher priority PLMN scan while the UE is in connected mode, determining, by the UE, whether a Rx chain is available; performing, by the UE, a <NUM> full band scan on a list of <NUM> frequencies and a <NUM> full band scan on a list of <NUM> frequencies in parallel in response to detecting that the Rx chain is available; and camping the UE based on the <NUM> full band scan or the <NUM> full band scan.

In an example embodiment camping the UE based on the <NUM> full band scan or the <NUM> full band scan comprises determining whether at least one of a <NUM> cell is available based on the <NUM> full band scan on the list of <NUM> MRU frequencies, or whether a <NUM> cell is available based on the <NUM> full band scan on the list of <NUM> MRU frequencies, and in response to determining that the <NUM> cell is available based on the <NUM> full band scan: camping the UE on the <NUM> cell, terminating the the <NUM> full band scan, and reporting a list of scanned cells resulted based on the <NUM> full band scan, or in response to determining that the <NUM> cell is available based on the <NUM> full band scan: camping the UE on the <NUM> cell, terminating the the <NUM> full band scan, and reporting a list of scanned cells resulted based on the <NUM> full band scan, or in response to determining that both the <NUM> cell is available based on the <NUM> full band scan and the <NUM> cell is available based on the <NUM> full band scan: camping the UE on the <NUM> cell, terminating the the <NUM> full band scan, and reporting a list of scanned cells resulted based on the <NUM> full band scan and a list of scanned cells resulted based on the <NUM> full band scan. In an example embodiment, the <NUM> cell with 5GC are preferred over <NUM> cell without 5GC.

In an example embodiment performing, by the UE, the <NUM> full band scan on the list of <NUM> frequencies and a <NUM> full band scan on the list of <NUM> frequencies in parallel comprises: detecting, by the UE, whether the UE is in <NUM> connected mode; and triggering the <NUM> full band scan on the list of <NUM> frequencies in background and the <NUM> full band scan on the list of <NUM> frequencies in foreground in response to determining that the UE is in the <NUM> connected mode, or triggering both the <NUM> full band scan on the list of <NUM> frequencies and the <NUM> full band scan on the list of <NUM> frequencies in foreground in response to determining that the UE is not in the <NUM> connected mode.

Accordingly various embodiments herein disclose the UE be camped on a cell, based on the UE being present in overlapping area of <NUM>th Generation (<NUM>) Stand Alone (SA), <NUM> Non-SA, and Long Term Evolution LTE, the UE comprises: a memory, a processor coupled to a communicator comprising communication circuitry, the UE configured to: create a combined Most Recently Used (MRU) list by merging a list <NUM> MRU frequencies with a Public Land Mobile Network (PLMN) having a 5GC and a list of <NUM> MRU frequencies, determine whether one of a <NUM> cell with <NUM> core and a <NUM> cell is available for camping the UE by performing a MRU scan on the combined MRU list, camp the UE on one of the <NUM> cell with <NUM> core and the <NUM> cell in response to determining that one of the <NUM> cell and the <NUM> cell with <NUM> core is available for camping the UE based on the MRU scan on the combined MRU list, or perform a <NUM> MRU frequency scan on a list of <NUM> MRU frequencies without 5GC in response to determining that one of the <NUM> cell with <NUM> core and the <NUM> cell is not available for camping the UE based on the MRU scan on the combined MRU list, and camping the UE based on the <NUM> MRU frequency scan.

Various example embodiments disclosed herein and the various features and advantageous details thereof are explained with reference to the non-limiting example embodiments that are illustrated in the accompanying drawings and described in the following disclosure. Descriptions of well-known components and processing techniques may be omitted so as to not unnecessarily obscure the embodiments herein. The various example embodiments disclosed herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments. The examples used herein are intended merely to facilitate an understanding of ways in which the various example embodiments herein can be practiced and to further enable those skilled in the art to practice the embodiments herein.

As is traditional in the field, embodiments may be described and illustrated in terms of blocks which carry out a described function or functions. These blocks, which may be referred to herein as managers, units, modules, hardware components or the like, are physically implemented by analog and/or digital circuits such as logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive electronic components, active electronic components, optical components, hardwired circuits and the like, and may optionally be driven by firmware. The circuits may, for example, be embodied in one or more semiconductor chips, or on substrate supports such as printed circuit boards and the like. The circuits of a block may be implemented by dedicated hardware, or by a processor (e.g., one or more programmed microprocessors and associated circuitry), or by a combination of dedicated hardware to perform some functions of the block and a processor to perform other functions of the block. Each block of the embodiments may be physically separated into two or more interacting and discrete blocks without departing from the scope of the disclosure. Likewise, the blocks of the embodiments may be physically combined into more complex blocks without departing from the scope of the disclosure.

The accompanying drawings are provided to aid in understanding various technical features and it should be understood that the various example embodiments presented herein are not limited by the accompanying drawings. As such, the disclosure should be construed to extend to any alterations, equivalents and substitutes in addition to those which are particularly set out in the accompanying drawings. These terms are simply used to distinguish one element from another.

Various example embodiments disclosed herein disclose a method and system for improving latency while camping the UE, when the UE is present in a <NUM> and a <NUM> overlapping area. Unlike conventional arts, in example embodiments, a combined MRU list is created by a MRU list creator by merging <NUM> MRU frequencies and <NUM> MRU frequencies having PLMN supported by <NUM> core (5GC). A cell selector scans the combined MRU list for finding the cell for camping the UE. If the UE is still not camped, then the cell selector performs a <NUM> full band scan using a first transceiver of the UE and performs a <NUM> full band scan in parallel using another transceiver of the UE.

Thus scanning the combined MRU list and/or performing the parallel <NUM> full band scan and <NUM> full band helps in reducing the latency of camping the UE thereby enabling quick camping.

Unlike conventional arts, the example embodiments have less delay in camping the cell while recovering from OOS mode or when powered on or when in in a connected mode. The various embodiments also reduce the delay while reporting the higher order PLMN.

Referring now to the drawings and more particularly to <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG> and <FIG> where similar reference characters denote corresponding features consistently throughout the figures, there are shown various example embodiments.

<FIG> is a block diagram illustrating an example UE <NUM>, wherein the UE <NUM> is present in <NUM> and <NUM> overlapping area according to various embodiments. The UE <NUM> may be in a connected state or idle state. The overlapping area may refer, for example, to the area where <NUM> cell connected with EPC or <NUM> Core are present.

The UE <NUM> may include, for example, and without limitation, a smart social robot, a smart watch, a cellular phone, a smart phone, a Personal Digital Assistant (PDA), a tablet computer, a laptop computer, a music player, a video player, an Internet of things (IoT) device, a smart speaker, an Artificial intelligent (AI) device, or the like. The UE <NUM> includes a memory <NUM>, a processor (e.g., including processing circuitry) <NUM>, a communicator (e.g., including communication circuitry) <NUM> and a cell selector (e.g., including processing circuitry and/or executable program elements) <NUM>.

The processor <NUM> is coupled to the memory <NUM>, and the communicator <NUM>. The processor <NUM> may include various processing circuitry, such as, for example, and without limitation, a general purpose processor, such as a central processing unit (CPU), an application processor (AP), a graphics-only processing unit such as a graphics processing unit (GPU), a visual processing unit (VPU), and the like. The processor <NUM> may include multiple cores or may have a single core. The processor <NUM> is coupled to the cell selector <NUM>, the memory <NUM>, and the communicator <NUM>. The processor <NUM> may include various processing circuitry and may be configured to execute instructions stored in the memory <NUM> and to perform various other processes.

The memory <NUM> stores instructions to be executed by the processor <NUM>. The memory <NUM> may include non-volatile storage elements. Examples of such non-volatile storage elements may include magnetic hard discs, optical discs, floppy discs, flash memories, or forms of erasable programmable read-only memories (EPROM) or electrically erasable programmable read-only memories (EEPROM). In addition, the memory <NUM> may, in some examples, be considered a non-transitory storage medium. The term "non-transitory" may indicate that the storage medium is not embodied in a carrier wave or a propagated signal. However, the term "non-transitory" should not be interpreted to be non-movable. In some examples, the memory <NUM> can be configured to store larger amounts of information than the memory. In certain examples, a non-transitory storage medium may store data that can, over time, change (e.g., in Random Access Memory (RAM) or cache).

The communicator <NUM> may include various communication circuitry and may be configured for communicating internally between internal hardware components and with external devices via one or more networks. The communicator <NUM> may include an electronic circuit specific to a standard that enables communication between internal hardware components and with external devices via one or more networks.

The cell selector <NUM> may include various processing circuitry and/or executable program elements and may be configured for searching a best available cell for the UE <NUM> for camping. The cell selector <NUM> may select the cell when the UE is either in connected state or in idle state and when the UE <NUM> is present in either of option <NUM>, option, <NUM> and option <NUM> of 3GPP standards of communication. As per 3GPP option <NUM> indicates that the UE <NUM> is in <NUM> standalone mode where the UE <NUM> is connected with eLTE Radio and EPC (Evolved Packet Core). Option <NUM> indicates that the UE <NUM> is in <NUM> standalone mode where the UE <NUM> is connected with NR Radio and <NUM> Core. Option <NUM> indicates that the UE <NUM> is in <NUM>+<NUM> mode wherein the UE <NUM> is connected with eLTE Radio and <NUM> Core.

In an embodiment, when the UE <NUM> is switched on or is in idle state then the UE needs to be camped on the cell for communication. The time taken by the UE <NUM> should be very low. The below described method ensures minimal and/or reduced delay in camping the UE <NUM> thereby improving latency.

In an embodiment, in finding the cell for camping, the cell selector <NUM>, may create a combined MRU (Most recently used) list by merging a list of <NUM> MRU frequencies with a Public Land Mobile Network (PLMN) having a 5GC and a list of <NUM> MRU frequencies. The <NUM> MRU frequencies with PLMN having 5GC comprises the <NUM> frequencies which are recently used by the UE <NUM> and which have <NUM> core. The <NUM> MRU frequencies are the <NUM> frequencies which are recently used by the UE <NUM>.

The cell selector <NUM> may perform a scan on the combined MRU list for determining whether one of a <NUM> cell with <NUM> core and a <NUM> cell is available for camping the UE <NUM>. The <NUM> cells are the cell supporting <NUM> Radio and connected with EPC or <NUM> core. The <NUM> cells are the cell supporting <NUM> radio connected with <NUM> core.

The UE <NUM> is camped on the <NUM> cell with <NUM> core if the <NUM> cell with <NUM> core is available. In an embodiment, the UE <NUM> is camped on the <NUM> cell if the <NUM> cell is available. In an embodiment if both the <NUM> cell with <NUM> core and the <NUM> cell are available then the cell selector <NUM> selects the <NUM> cell for camping.

If both the <NUM> cell with <NUM> core and the <NUM> cell are not available the cell selector <NUM> performs a <NUM> MRU frequency scan. The <NUM> MRU frequency scan is performed on a list of <NUM> MRU frequencies without 5GC. The UE <NUM> is camped on a <NUM> cell with EPC core if the cell <NUM> cell with EPC core is found. In an embodiment, the UE determines whether a SIB (system information block) <NUM> message is present providing details about a NR radio after camping on the <NUM> cell with EPC core. If the NR information is present the UE searches for neighboring <NUM> cell for camping the UE. If the NR information is not present, the UE <NUM> is camped on the <NUM> cell without 5GC.

In an embodiment, if the cell is not found in the <NUM> MRU scan, the cell selector <NUM> performs a <NUM> full band and <NUM> full band scan in parallel. The <NUM> full band scan includes scanning all the available <NUM> frequencies in a <NUM> list with and without <NUM> core for finding the 4Gcell with or without <NUM> core for camping the UE <NUM>. The <NUM> full band scan includes scanning all the available <NUM> frequencies in a <NUM> list for finding the <NUM> cell for camping the UE <NUM>.

During parallel scanning of <NUM> full band and <NUM> full band, the UE <NUM> the may be camped on either <NUM> cell or the <NUM> cell. If the <NUM> cell is found before the <NUM> cell then the UE <NUM> is camped on the <NUM> cell. The <NUM> cell on which the UE <NUM> is camped during the parallel scanning may have PLMN supported by 5GC or EPC. In an embodiment, the UE determines whether the SIB24 message is present providing details about the NR radio. If the NR information is present the UE searches for neighboring <NUM> cell for camping the UE. If the NR information is not present, the UE <NUM> is camped on the <NUM> cell without 5GC.

If the <NUM> cell is found before the <NUM> cell the UE <NUM> is camped on the <NUM> cell. In an embodiment, if both the <NUM> cell and the 5C cell are found simultaneously, the UE <NUM> is camped on the <NUM> cell.

If the UE <NUM> is not camped on any cell during parallel scanning of <NUM> full band and <NUM> full band, due to unavailability of the cell, the UE <NUM> performs a legacy scan. The legacy scan includes scanning <NUM> frequencies followed by <NUM> frequencies for finding the cell for camping the UE <NUM>.

In an embodiment, when the UE <NUM> is in connected state, the UE <NUM> performs a higher priority PLMN search. Searching higher priority PLMN is explained in 3GPP specification at 3GPP SP TS <NUM>. under Automatic Network Selection Mode Procedure.

The UE <NUM> also determines the cell to which it is connected. The UE <NUM> performs the <NUM> full band scan and the <NUM> full band scan in parallel. If the UE <NUM> determines that the cell to which the UE <NUM> is already connected is the <NUM> cell the <NUM> full scan band is performed in background. The <NUM> full band scan is performed on the list of <NUM> frequencies and the <NUM> full band scan is performed on the list of <NUM> frequencies.

The cell found during scanning is reported to upper layers. The upper layers are the mobility management layer and the application layer. <FIG> shows a limited overview of the UE <NUM> but it is to be understood that other embodiments are not limited thereto.

<FIG> is a block diagram illustrating an example configuration of the cell selector <NUM> illustrating various components for selecting the cell for camping the UE <NUM>, when the UE is present in overlapping area of <NUM> SA, <NUM> Non-SA, and LTE according to various embodiments.

The cell selector <NUM> includes a combined MRU list creator (e.g., including various processing circuitry and/or executable program elements) <NUM>, a <NUM> cell selector (e.g., including various processing circuitry and/or executable program elements) <NUM>, a <NUM> cell selector (e.g., including various processing circuitry and/or executable program elements) <NUM> and a higher priority PLMN identifier (e.g., including various processing circuitry and/or executable program elements) <NUM>. When the UE <NUM> is in idle mode or is switched on or is recovering from out of service mode then the UE <NUM> needs to camp on a cell for communication. The cell on which the UE <NUM> is camped may be a <NUM> cell or a <NUM> cell based on the availability.

As discussed above existing methods first perform a <NUM> MRU scan followed by a 4GMRU scan. If the cell is not found in MRU frequencies then the UE <NUM> performs a <NUM> full band scan. If the cell is not found in <NUM> full band scan then the UE <NUM> performs <NUM> full band scan, due to which there is a lot of (e.g., relatively long) delay. Whereas the current method reduces the delay in searching the cell for camping the UE <NUM>. The combined MRU list creator <NUM> may include various processing circuitry and/or executable program elements and creates the combined MRU list by merging the list of <NUM> MRU frequencies having PLMN supported by 5GC and the list of <NUM> MRU frequencies. The <NUM> cell selector <NUM> and the <NUM> cell selector <NUM> may include various processing circuitry and/or executable program elements and perform a scan on the combined MRU list for finding the <NUM> cell with <NUM> core and the <NUM> cell respectively for camping the UE <NUM>. The UE <NUM> is camped on the <NUM> cell with <NUM> core if the <NUM> cell with <NUM> core is found first or is camped on <NUM> cell if the <NUM> cell is found first.

In an embodiment, if the cell for camping is not found in the combined MRU list, then the <NUM> cell selector <NUM> performs the scan on the <NUM> MRU frequencies without 5GC (with EPC) for finding the cell for camping the UE <NUM>. If the <NUM> cell with EPC is found then the UE <NUM> is camped. In an embodiment, the UE (e.g., higher priority PLMN identifier <NUM>) determines whether the SIB24 message is present providing details about the NR radio. If the NR information is present then the UE (e.g., higher priority PLMN identifier <NUM>) searches for neighboring <NUM> cell for camping the UE. If the NR information is not present, then the UE <NUM> is camped on the <NUM> cell without 5GC.

If the <NUM> cell with EPC is not found in the list of <NUM> MRU frequencies with EPC, then the <NUM> cell selector <NUM> performs the <NUM> full band scan and the <NUM> cell selector <NUM> performs the <NUM> full band scan in parallel. The <NUM> full band scan is performed on the list comprising all the <NUM> frequencies with 5GC and EPC. The <NUM> full band scan is performed on the list comprising all the <NUM> frequencies. If the <NUM> cell selector <NUM> finds the <NUM> cell during the <NUM> full band scan, then the UE <NUM> is camped on the <NUM> cell found during the full band scan and the <NUM> full band scan is terminated. Similarly if the <NUM> cell selector <NUM> finds the <NUM> cell during the <NUM> full band scan, then the UE <NUM> is camped on the <NUM> cell found during the full band scan and the <NUM> full band scan is terminated. In an embodiment, during the <NUM> full band scan the <NUM> cell selector <NUM> searches for the <NUM> cell with 5GC first and if the <NUM> cell with 5GC is not found then the <NUM> cell selector <NUM> searches for the <NUM> cell without 5GC. In an embodiment, the UE determines whether the SIB24 message is present providing details about the NR radio. If the NR information is present the UE searches for neighboring <NUM> cell for camping the UE. If the NR information is not present, the UE <NUM> is camped on the <NUM> cell without 5GC.

If the cell for camping the UE <NUM> is not found after the <NUM> full band scan and the <NUM> full band scan, then the cell selector <NUM> performs the legacy scan.

When the UE <NUM> is in connected mode then the cell selector <NUM> performs the high priority PLMN scan using the higher priority PLMN identifier <NUM>.

<FIG> is a diagram, illustrating example creation of combined MRU list, according various embodiments.

The <NUM> MRU frequencies include the <NUM> frequencies which have been recently used by UE <NUM>. The <NUM> MRU frequencies include two types the <NUM> frequencies with PLMN having 5GC support (based on LTE cell indication to support <NUM> core network in SIB1 using IE: CellAccessRelatedInfoList-5GC) and <NUM> frequencies with PLMN not having 5GC support. The <NUM> MRU frequencies include the <NUM> frequencies which have been recently used by the UE <NUM>.

At <NUM>, the combined MRU list creator <NUM>, merges the list comprising <NUM> MRU frequencies with the list comprising the <NUM> MRU frequencies having PLMN supported by the 5GC. The combined MRU list is stored <NUM> and scanned <NUM> by the <NUM> cell selector <NUM> and the <NUM> cell selector for selecting either the <NUM> cell or the <NUM> cell respectively. The UE <NUM> is camped <NUM> on the best available cell in found after the combined MRU scan. If the cell is not found after the combined MRU scan, the <NUM> MRU frequency list comprising <NUM> MRU frequencies without 5GC are scanned,.

Thus the two frequency lists namely the <NUM> MRU frequency list and the <NUM> MRU frequency list having PLMN supported by 5GC are scanned together which saves the time as compared to the prior art where the <NUM> MRU frequencies are scanned first followed by <NUM> MRU frequencies with 5GC, further followed by <NUM> MRU frequencies without 5GC.

<FIG> is a diagram, illustrating an example interface for parallel scanning of the <NUM> full band scan and the <NUM> full band scan, according to various embodiments.

As illustrate in <FIG>, <NUM> indicates the <NUM> NAS in communication with <NUM> AS <NUM>. Similarly <NUM> indicates <NUM> NAS which is communicating with <NUM> AS <NUM>. A new interface is introduced between <NUM> NAS <NUM> and <NUM> AS <NUM> which enables communication while parallel scanning of the <NUM> full band and the <NUM> full band.

In an embodiment, the new interface provides communication between <NUM> NAS (upper layers) and <NUM> AS (lower layer). <NUM> NAS and <NUM> AS may exchange commands related to frequency band and PLMN selection.

<FIG> is a flowchart illustrating an example method for camping the UE <NUM> in the <NUM> and <NUM> overlapping area when the UE <NUM> is powered on or is in OOS recovery mode, according to various embodiments.

At <NUM>, the combined MRU list creator <NUM> merges the list comprising <NUM> MRU frequencies and the list comprising <NUM> MRU frequencies with PLMN having 5GC for creating the combined MRU list. At 604A and 604B, the <NUM> cell selector <NUM> and the <NUM> cell selector <NUM> scans the combined MRU list for finding the cell for camping the UE <NUM>. At <NUM>, the <NUM> cell selector <NUM> and the <NUM> cell selector <NUM> determines whether the <NUM> cell or the <NUM> cell having PLMN with 5GC is found. If the cell is not found to the method performs operation <NUM>. In an embodiment, at <NUM>, the UE <NUM> is camped on the <NUM> cell in response to determining that the <NUM> cell selector <NUM> has found the <NUM> cell after scanning the combined MRU list. In an embodiment at <NUM>, the UE <NUM> is camped on the <NUM> cell having PLMN supported with 5GC in response to determining that the <NUM> cell selector <NUM> has found the <NUM> cell having PLMN supported with 5GC. Once the UE <NUM> is camped at <NUM>, the method flow is stopped here.

At <NUM>, the <NUM> cell selector <NUM> scans the list comprising <NUM> MRU frequencies without 5GC. At <NUM>, the cell selector <NUM> determines whether the <NUM> cell without 5GC is found. If the <NUM> cell without 5GC is found, the method proceeds to <NUM> else to <NUM>. At <NUM>, the UE <NUM> is camped on the <NUM> cell without 5GC found after scanning the list comprising the <NUM> cell without 5GC. Once the UE <NUM> is camped at <NUM>, the method proceeds to <NUM>. At <NUM>, the UE determines whether the SIB24 message is present providing details about the NR radio. If the NR information is present the UE searches for neighboring <NUM> cell for camping the UE and the UE <NUM> is camped on the <NUM> cell at <NUM>.

If the NR information is not present, the UE <NUM> is camped on the <NUM> cell without 5GC in <NUM> and the method flow is stopped. However if the UE <NUM> is not camped at <NUM>, the method flow <NUM> is directed to <NUM> and <NUM>.

At <NUM>, the <NUM> cell selector <NUM> scans the list including all the <NUM> frequencies which may be referred to as <NUM> full band scan. At <NUM>, the <NUM> cell selector <NUM> scans the list including all the <NUM> frequencies which may be referred to as <NUM> full band scan in parallel to the <NUM> full band scan at <NUM>. At <NUM>, the <NUM> cell selector <NUM> and the <NUM> cell selector <NUM> determines whether the <NUM> cell with or without PLMN having 5GC or the <NUM> cell is found for camping the UE <NUM> during the parallel scanning of the <NUM> full band and the <NUM> full band. If the <NUM> cell with 5GC is found the method <NUM> proceeds to <NUM>. If the <NUM> cell is found then the method proceeds to <NUM>. If neither <NUM> cell with 5GC nor <NUM> cell is found the method proceeds to <NUM>. In an embodiment The UE <NUM> is camped on either the <NUM> cell with 5GC or the <NUM> cell whichever is found first. For example if the <NUM> cell during the <NUM> full band scan at <NUM> is found first then the UE <NUM> is camped on the <NUM> cell and the <NUM> full band scanning at <NUM> is terminated.

At <NUM>, the UE <NUM> is camped on the <NUM> cell with 5GC found during scanning at <NUM> and the scanning of the <NUM> full band at <NUM> is terminated.

At <NUM>, the UE <NUM> is camped on the <NUM> cell found during the <NUM> full band scan at <NUM>, and the <NUM> full band scan at <NUM> is terminated.

In an embodiment at <NUM>, the UE <NUM> is camped on the <NUM> cell without 5GC found during the <NUM> full band scan at <NUM>. In an embodiment at <NUM>, the <NUM> cell selector <NUM> determines whether a SIB24 message is present providing details about NR radio at <NUM>. If the NR information is present then the cell selector <NUM> searches for the <NUM> cell for camping the UE <NUM> and camps the UE at <NUM>. If the NR information is not present, then the UE <NUM> is camped on the <NUM> cell without 5GC.

If the UE <NUM> is not camped on any cell after the parallel scanning of the <NUM> full band the <NUM> full band, the legacy scan is performed for finding the cell for camping the UE <NUM>.

<FIG> is a flowchart illustrating a method for camping the UE <NUM>, when the UE <NUM> is in the <NUM> and <NUM> overlapping area and is in connected state according to various embodiments.

In an embodiment, the UE <NUM> is already camped on any cell and is in connected mode. The higher priority PLMN search is performed to camp the UE <NUM> on a higher priority cell.

The operations for searching the higher priority PLMN are same as or similar to that explained in <FIG>.

At <NUM>, the UE <NUM> is in connected state and the UE <NUM> initiates a searches for the higher priority PLMN. The UE <NUM> scans the combined MRU list, followed by <NUM> MRU frequencies without 5GC.

Further, step <NUM> and step <NUM> are performed in parallel. At <NUM>, <NUM> full band scan is performed. At <NUM><NUM> full band scan is performed. In an embodiment, if the <NUM> stack is in connected mode, then the <NUM> full band scan is performed in background.

At <NUM>, the PLMN list including the available cell is reported to higher layers.

<FIG> is a signal flow diagram, illustrating an example method for camping the UE <NUM> in the <NUM> and <NUM> overlapping area when the UE <NUM> is powered on or is in OOS recovery mode, according to various embodiments.

As illustrate in <FIG>, <NUM> indicates <NUM> Non-Access Stratum (<NUM>-NAS), <NUM> indicates <NUM> Non-Access Stratum (<NUM>-NAS), <NUM> indicates <NUM> Standalone (<NUM>-AS) and <NUM> indicates <NUM> Access Stratum (4GAS).

At <NUM>, the UE <NUM> is powered up or is recovering from OOS mode. At <NUM>, the combined MRU scan is performed on the list of the <NUM> MRU frequencies and the list of <NUM> MRU frequencies with 5GC. At 806a, the UE <NUM> is camped on the <NUM> cell if the <NUM> cell is found after scanning the combined MRU list. In an embodiment at 806b, the UE <NUM> is camped on the <NUM> cell having PLMN supported with 5GC if the <NUM> cell having PLMN supported with 5GC is found.

If the UE <NUM> is not camped on any cell after combined MRU scan then the full band <NUM> scan is performed in parallel to full band <NUM> scan at <NUM>. In an embodiment, the scan is performed on the 4GMRU frequencies without 5GC before performing full band scans at <NUM>.

At 810a, the UE <NUM> is camped on the <NUM> cell if the <NUM> cell is found during the full band scan and the <NUM> full band scan is terminated. At 810b, the UE <NUM> is camped in the <NUM> cell with 5GC if the <NUM> cell with the <NUM> core is found first and the <NUM> full band scan is terminated.

<FIG> is signal flow diagram, illustrating an example method of performing the higher priority PLMN search for camping the UE <NUM>, according to various embodiments.

As illustrated in <FIG>, at <NUM>, the higher priority PLMN scan is performed. The UE <NUM> may be in <NUM> connected mode or may not be connected to a <NUM> stack. At <NUM>, the <NUM> full band scan is performed in parallel to <NUM> full band scan. If the UE <NUM> is connected to <NUM> stack already then the <NUM> full band scan is performed in background.

At Step 906a, the <NUM> cell is found and the <NUM> full band scan is terminated. At 908a, the UE <NUM> is camped on the <NUM> cell. In an embodiment if the <NUM> cell with 5GC is found at 906b, then the <NUM> full band scan is terminated. At 908b the UE <NUM> is camped on the <NUM> cell with 5GC.

<FIG> is a diagram illustrating a conventional implementation indicating a delay in camping the UE on <NUM> where stored frequencies are not present due to <NUM> scan, according to the prior art.

As illustrated in <FIG>, the UE <NUM> is present in location A and is registered on <NUM>. The UE <NUM> moves to other city at location B via airplane. During travel, the UE <NUM> is in airplane mode. Once the airplane mode is off after reaching the location B, the UE <NUM> scans <NUM> MRU frequencies. If no cell is found the UE performs the scan on the <NUM> MRU frequencies, In an embodiment, if no cell is available in the <NUM> MRU scan MRU scan, the UE <NUM> performs <NUM> full band followed by <NUM> full band scan. If the <NUM> frequencies are not available, the UE <NUM> is camped on the cell available in the <NUM> frequencies. Thus as seen, there is a large delay in camping the UE <NUM> on the <NUM> cell.

<FIG> is a diagram, illustrating an example method, according to various embodiments.

As illustrated in <FIG>, the UE <NUM> is present in location A and is registered on <NUM>. The UE <NUM> moves to other city at location B via airplane. During travel, the UE <NUM> is in airplane mode. Once the airplane mode is off after reaching the location B, the UE <NUM> scans <NUM> MRU frequencies in parallel to <NUM> MRU frequencies, which is the MRU scan on the combined MRU list as explained above. The UE <NUM> camps on any cell found in the combined MRU scan, thus saving the camping time.

However if no cell is available in the combined MRU scan, the UE <NUM> performs <NUM> full band scan in parallel to <NUM> full band scan. If the <NUM> frequencies are not available, the UE <NUM> is camped on the cell available in the <NUM> frequencies. Thus as seen, there the delay in camping the UE <NUM> is reduced.

However if no cell is available in the combined MRU scan, the UE <NUM> performs <NUM> full band scan in parallel to <NUM> full band scan. The UE <NUM> find <NUM> cell. Here the UE <NUM> finds SIB24 message and reads the information about neighboring <NUM> cells in the SIB24 message. Thus the UE <NUM> is camped on the <NUM> cell based on the information present in the SIB24 message. Thus as seen, there the delay in camping the UE <NUM> is reduced.

In an embodiment, if the UE <NUM> is not camped on any cell after the parallel scanning of the <NUM> full band the <NUM> full band, the legacy scan is performed for finding the cell for camping the UE <NUM>.

Claim 1:
A method of camping a user equipment, UE, (<NUM>) on a cell, based the UE being present in overlapping <NUM>th generation, <NUM>, and <NUM>th generation, <NUM>, areas, the method comprising:
creating (<NUM>), by the UE, a combined most recently used, MRU, list by merging a list of <NUM> MRU frequencies having a <NUM> core, 5GC, and a list of <NUM> MRU frequencies;
determining (<NUM>), by the UE, whether one of a <NUM> cell with <NUM> core and a <NUM> cell is available for camping the UE by performing (604A, 604B) a MRU scan on the combined MRU list;
performing (<NUM>) a <NUM> MRU frequency scan on a list of <NUM> MRU frequencies without 5GC in response to determining that one of the <NUM> cell with <NUM> core and the <NUM> cell is not available for camping the UE based on the MRU scan on the combined MRU list; and
camping (<NUM>) on a <NUM> cell without 5GC in response to determining that the <NUM> cell without 5GC is available for camping the UE based on the <NUM> MRU frequency scan on the list of <NUM> MRU frequencies without 5GC,
wherein performing the MRU scan on the combined MRU list comprises performing a <NUM> MRU frequency scan (604A) on the list of <NUM> MRU frequencies in parallel to with a <NUM> with 5GC MRU frequency scan (604B) on the list of <NUM> MRU frequencies having the 5GC.