CLIAMS:We claim:
1) A method for performing reference data assisted Public Land Mobile Network (PLMN) search by a User Equipment (UE), said method comprising:
identifying at least one PLMN in said UE’s location as result of a first level of search, by a PLMN selection module present in said UE;
verifying said result of said first level of search by said PLMN selection module, wherein said verifying involves checking if said results cover all PLMNs in said location; and
performing a second level search by said PLMN selection module if said result of said first level search do not cover all PLMNs in said location, wherein said second level search identifies at least one PLMN missed during said first level search.
2) The method as claimed in claim 1, wherein said verifying said result of first level search further comprises:
identifying PLMN Id corresponding to said identified PLMN, by a PLMN selection module; and
comparing said identified PLMN Id with a reference database by said PLMN selection module, wherein said reference database possesses information on all PLMNs and corresponding PLMN Ids.
3) The method as claimed in claim 2, wherein said information on PLMNs and corresponding PLMN Ids is location specific.
4) The method as claimed in claim 1, wherein performing said second level search further comprises:
identifying at least one PLMN missed out during said first level search, by a PLMN selection module;
populating a plurality of cells of said at least one PLMN, by said PLMN selection module; and
searching for at least one valid cell among said plurality of cells by said PLMN selection module, wherein said valid cell meets a pre-configured criteria in terms of signal strength and type of services being handled.
5) The method as claimed in claim 4, wherein said identifying said at least one PLMN missed out during said first level search further comprises comparing results of said first level search with a reference database, by said PLMN selection module.
6) A User Equipment (UE) for performing reference data assisted Public Land Mobile Network (PLMN) search, said UE further configured for:
identifying at least one PLMN in said UE’s location as result of a first level of search, by a PLMN selection module present in said UE;
verifying said result of said first level of search by said PLMN selection module, wherein said verifying involves checking if said results cover all PLMNs in said location; and
performing a second level search by said PLMN selection module if said result of said first level search do not cover all PLMNs in said location, wherein said second level search identifies at least one PLMN missed out during said first level search.
7) The UE as claimed in claim 6, wherein said PLMN selection module is further configured for verifying said result of said first level search by:
identifying PLMN Id corresponding to said identified PLMN, using a scanning module; and
comparing said identified PLMN Id with a reference database using said scanning module, wherein said reference database possesses information on a plurality of PLMNs and PLMN Id corresponding each of said plurality of PLMNs, in said location.
8) The UE as claimed in claim 6, wherein said PLMN selection module is further configured for performing said second level search by:
identifying at least one PLMN missed out during said first level search, using a scanning module;
populating cells of said at least one PLMN, using said scanning module; and
searching for at least one valid cell among said populated cells using said scanning module, wherein said valid cell meets pre-configured criteria in terms of signal strength and type of services being handled.
9) The UE as claimed in claim 8, wherein said scanning module is further configured to identify said at least one PLMN missed out during said first level search by comparing results of said first level search with a reference database.

Date: 26 February 2015 Signature:
Kalyan Chakravarthy
,TagSPECI:FORM 2
The Patent Act 1970
(39 of 1970)
&
The Patent Rules, 2005

COMPLETE SPECIFICATION
(SEE SECTION 10 AND RULE 13)

TITLE OF THE INVENTION

“Enhanced PLMN search in a communication network”

APPLICANT:

Name Nationality Address
SAMSUNG R&D Institute India - Bangalore Private Limited India # 2870, Orion Building, Bagmane Constellation Business Park, Outer Ring Road, Doddanekundi Circle, Marathahalli Post, Bangalore-560037, India

The following specification particularly describes and ascertains the nature of this invention and the manner in which it is to be performed:-

FIELD OF INVENTION
[001] The present invention relates to the field of telecommunication and more particularly to reference data assisted Public Land Mobile Network (PLMN) search in the telecommunication network.

BACKGROUND OF INVENTION
[002] A User Equipment (UE) in a telecommunication network connects to a corresponding Public Land Mobile Network (PLMN) network to avail mobile as well as other value added services. The UE has two modes for PLMN selection, namely the Automatic and Manual Modes. When the automatic mode is turned ON, the UE automatically searches for available PLMN networks in the UE’s location. In the manual mode, the user may have to initiate the search, and further manually select a network from the list that the UE displays to the user upon finishing the search.
[003] While performing the PLMN search, due to bad signal strength, which might be a temporary issue, the UE might not identify most desirable PLMN which can provide the type of service(s) the UE has requested for, and at optimal cost of the service. As a result, during the search, the UE may end up not receiving required services at optimal service charges, though cell(s) which can provide the required service(s) is available in the UE’s location, but with weak signal strength.

OBJECT OF INVENTION
[004] The principal object of the embodiments herein is to perform reference data assisted Public Land Mobile Network (PLMN) search in a location.
[005] Another object of the invention is to update a reference database with latest data on PLMNs and corresponding PLMN Ids, in a location.
SUMMARY
[006] Accordingly the invention provides a method for performing reference data assisted Public Land Mobile Network (PLMN) search by a User Equipment (UE). At least one PLMN is identified in the UE’s location as result of a first level of search, by a PLMN selection module present in the UE. The PLMN selection module then verifies the result of the first level of search, wherein the verifying involves checking if the results cover all PLMNs in the location. If the results of first level search do not cover all PLMNs in the location, a second level search is performed by the PLMN selection module, wherein the second level search identifies at least one PLMN missed during the first level search.
[007] Accordingly the invention provides a User Equipment (UE) for performing reference data assisted Public Land Mobile Network (PLMN) search. The UE is further configured for identifying at least one PLMN in the UE’s location as result of a first level of search, by a PLMN selection module present in the UE. The UE further verifies the result of the first level of search by the PLMN selection module, wherein the verifying involves checking if the results cover all PLMNs in the location. Further, if the results of the first level search do not cover all PLMNs in the location, a second level search is performed by the PLMN selection module, wherein the second level search identifies at least one PLMN missed out during the first level search.
[008] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF FIGURES
[009] This invention is illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0010] FIG. 1 illustrates a block diagram of a PLMN (Public Land Mobile Network) connected to at least one User Equipment (UE), according to embodiments as disclosed herein;
[0011] FIG. 2 illustrates a block diagram which shows various components of the PLMN selection module, according to embodiments as disclosed herein;
[0012] FIG. 3 is a flow diagram depicting various steps involved in the process of reference data assisted PLMN search, according to embodiments as disclosed herein; and
[0013] FIG. 4 is a flow diagram depicting various steps involved in the process of updating a reference database, according to embodiments as disclosed herein.

DETAILED DESCRIPTION OF INVENTION

[0014] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein can be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0015] The embodiments herein achieve a reference data assisted Public Land Mobile Network (PLMN) search in a telecommunication network. Referring now to the drawings, and more particularly to FIGS. 1 through 4, where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments.
[0016] FIG. 1 illustrates a block diagram of a PLMN (Public Land Mobile Network) connected to at least one User Equipment (UE), according to embodiments as disclosed herein. The PLMN 103 is connected to at least one UE 101 using a suitable communication channel. The UE 101 may be any suitable communication device such as, but not limited to a mobile phone, a tablet that supports SIM and audio calling. The UE 101 further comprises of a PLMN selection module 102.
[0017] The PLMN selection module 102 in the UE 101 can be configured to perform the PLMN search and to identify all PLMNs 104 in the location. In an embodiment, the PLMN selection module 102 can initiate the PLMN search process automatically. In another embodiment, the PLMN selection module 102 may require the user to provide manual request so as to initiate the PLMN search process.
[0018] In a preferred embodiment, the PLMN selection module 102 can perform a dual step PLMN search. The PLMN selection module 102 may be configured to use any suitable PLMN search process in a first level of the dual step PLMN search. The PLMN selection module 102 may be further configured to verify whether the first step could identify all PLMNs in that particular location, based on recent past search result data information stored as the reference data. The PLMN selection module 102 may be further configured to perform a second level search upon identifying that the first level search did not find all PLMNs in that location. In a preferred embodiment, the PLMN selection module 102 may be configured to use reference data i.e. recent past search result data pertaining to previous PLMN searches, and PLMNs identified in that location during previous searches, to identify whether the first level of search has covered all PLMNs in that location. The reference data may be further used by the PLMN selection module 102 so as to identify PLMNs that were missed out during the first level of search.
[0019] The PLMN selection module 102 can be further configured to verify result of the first level of search to check if the result covers all PLMNs in that location. The PLMN selection module 102 can be further configured to perform a second level search upon identifying that the results of first level search has not covered all PLMNs in that location, wherein the second level search is needed to be triggered if, at least one PLMN missed out during the first level of search based on the reference data base available.
[0020] FIG. 2 illustrates a block diagram which shows various components of the PLMN selection module, according to embodiments as disclosed herein. The PLMN selection module 102 further comprises of a scanning module 201, a memory module 202, a timer module 203, and an updation module 204. The scanning module 201 may be configured to search and identify PLMNs in any specific location. In various embodiments, the scanning module 201 may initiate the search process automatically or upon receiving manual instruction from a user, based on configured settings of the UE 101. The scanning module 201 may be configured to communicate with the memory module 202 to access information stored in a verification database, and/or any data required for the PLMN search purpose.
[0021] The memory module 202 may be configured to store information pertaining to previous PLMN searches, search results, as a reference database, with corresponding location information. The memory module 202 may be further configured to save any other information required for the purpose of the dual step PLMN search. In various embodiments, the memory module 202 may be internal or external to the PLMN selection module 102. Further, the memory module 202 may be in any suitable form such as but not limited to permanent memory, temporary memory, fixed memory, expandable memory, and removable memory cards, as supported by the UE 101.
[0022] The updation module 204 can be configured to identify and update changes pertaining to data saved in the memory module 202. The updation module 204 can be further configured to update the memory module 203 with new data pertaining to the dual step PLMN search process.
[0023] The timer module 203 may be configured to provide time instances as input, which may be used by the scanning module 201, the memory module 202, and the updation module 204 while executing various steps involved in the dual step PLMN search process. For example, the memory module 202 can use the time information collected from the timer module 203 to add time instances to the recent past search result data stored as the reference data. The updation module 204 can use the time information collected from the timer module 203 to save time instances of data updation in the memory module 202. The timer module may be in any suitable format as supported by the UE 101, and may be kept internal or external to the UE 101.
[0024] FIG. 3 is a flow diagram depicting various steps involved in the process of reference data assisted PLMN search, according to embodiments as disclosed herein. The PLMN selection module 102 in the UE 101 performs search for PLMNs in UE’s location, using any suitable PLMN searching method/algorithm. In various embodiments, the PLMN search is manually or automatically triggered.
[0025] In a preferred embodiment, the PLMN selection module 102 performs a dual level search. In the first level, the PLMN selection module 102 initiates (302) search for pending bands in the location. If any pending band is found (304) during the search, the scanning module 201 in the PLMN selection module 102 scans (306) the band and prepares a channel list that comprises list of channels available under that particular band.
[0026] Further, the PLMN selection module 102 checks (308) if any valid channel is present in the list of channels identified. In a preferred embodiment, the PLMN selection module 102 checks if a channel is valid or not, based on signal strength threshold.
[0027] Upon identifying at least one valid channel, the PLMN selection module 102 scans the channel to check (310) and identify at least one valid cell in the channel, wherein the cell meets requirements in terms of signal strength, type of services being offered, and any other parameter. If at least one valid cell is identified, then the PLMN selection module 102 checks (312) if cell has been listed in the reference database or not. If the cell is listed in the reference database along with valid PLMN id, the PLMN selection module 102 marks the PLMN Id’s detected information by resetting the timer in the reference database. This cell may be used by the UE 101 for the purpose of communication.
[0028] If the identified cell is listed in the reference database, then the PLMN selection module 102 verifies if signal strength of the cell at that instant of time is meeting a set threshold value. In an embodiment, the threshold value is pre-configured by an authorized person such as an administrator, based on various network requirements.
[0029] If the signal strength of the cell meets (324) the threshold value, then the PLMN selection module 102 selects and marks (326) the cell as suitable for communication. The cell(s) marked as suitable for communication may be used by the UE 101 for the purpose of communication. If the valid cell is not listed in the reference database or if the signal strength of the cell is not meeting the threshold limit, the PLMN selection module 102 identifies (314) PLMN Id of the cell by reading the broadcast channels of the cell. If the PLMN Id is not present in the data base, new entry is made for the cell, after identifying the PLMN Id.
[0030] Further, the PLMN selection module 102 scans next channel if any, for identifying valid channels and valid cells. The PLMN selection module 102 can consider (322) the next channel and search for valid cells under various other circumstances. For example, if the channel being considered is not a valid channel, then the PLMN selection module 102 can directly consider next channel if any, without scanning cells in that particular channel.
[0031] Upon completing the first level search and upon populating the results, the PLMN selection module 102 checks (316) if the search result has covered all PLMNs in that location. In a preferred embodiment, the PLMN selection module 102 checks if the search has covered all PLMNs in that location, by comparing the results with a reference database present in the memory module 203, wherein the reference database possesses information on past/recent past search results, PLMNs identified in that particular location, and PLMN Ids of all PLMNs in that location. In another preferred embodiment, the reference database is updated on a regular basis.
[0032] If the first level search has covered all PLMNs in that location, then the PLMN selection module 102 terminates (328) the scan for pending bands. If the first level search has not covered all PLMNs in that location, then the PLMN selection module 102 populates (318) cell(s) that belong to the PLMN Id that was identified as missing from the results of the first level search. Further, the PLMN selection module 102 searches (320) among the populated cell list to identify at least one valid cell.
[0033] The various actions in method 300 may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some actions listed in FIG. 3 may be omitted.
[0034] FIG. 4 is a flow diagram depicting various steps involved in the process of updating a reference database, according to embodiments as disclosed herein. The process of updating the reference database may involve updating PLMN Id of the PLMNs information pertaining to which are stored in the database.
[0035] The PLMN selection module 102 initiates (402) a PLMN Id read process which involves reading PLMN Id of cells identified in that location. If the PLMN Id read process is successful (404) for any cell, the PLMN selection module 102 checks (406) if information pertaining to that particular cell is present in the reference database. If the information pertaining to that cell is present in the reference database, then the PLMN selection module 102 checks if any reference parameter specific to that cell has changed. For example, the PLMN Id associated with that cell may have changed. In that scenario, the PLMN selection module 102 resets (408) the timer module 203 and updates the reference database with the PLMN Id.
[0036] If the information pertaining to the cell is not specified in the reference database, then the PLMN selection module 102 checks (412) if there is sufficient space available in the reference database to add the information pertaining to the cell identified. If space is not available, then the PLMN selection module 102 removes (414) oldest cell of the same PLMN Id from the reference database. If sufficient space is available in the reference database, then the PLMN selection module 102 adds (416) the cell information to the database.
[0037] The various actions in method 400 may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some actions listed in FIG. 4 may be omitted.
[0038] The dual level search ensures that the UE 101 identifies all PLMNs in the UE’s location, so that the UE 101 can select a cell that can provide required services and desired signal strength. The embodiments disclosed herein can be implemented through at least one software program running on at least one hardware device and performing network management functions to control the elements. The elements shown in Fig. 1 can be at least one of a hardware device, or a combination of hardware device and software module.
[0039] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

CLAIMS
We claim:
1) A method for performing reference data assisted Public Land Mobile Network (PLMN) search by a User Equipment (UE), said method comprising:
identifying at least one PLMN in said UE’s location as result of a first level of search, by a PLMN selection module present in said UE;
verifying said result of said first level of search by said PLMN selection module, wherein said verifying involves checking if said results cover all PLMNs in said location; and
performing a second level search by said PLMN selection module if said result of said first level search do not cover all PLMNs in said location, wherein said second level search identifies at least one PLMN missed during said first level search.
2) The method as claimed in claim 1, wherein said verifying said result of first level search further comprises:
identifying PLMN Id corresponding to said identified PLMN, by a PLMN selection module; and
comparing said identified PLMN Id with a reference database by said PLMN selection module, wherein said reference database possesses information on all PLMNs and corresponding PLMN Ids.
3) The method as claimed in claim 2, wherein said information on PLMNs and corresponding PLMN Ids is location specific.
4) The method as claimed in claim 1, wherein performing said second level search further comprises:
identifying at least one PLMN missed out during said first level search, by a PLMN selection module;
populating a plurality of cells of said at least one PLMN, by said PLMN selection module; and
searching for at least one valid cell among said plurality of cells by said PLMN selection module, wherein said valid cell meets a pre-configured criteria in terms of signal strength and type of services being handled.
5) The method as claimed in claim 4, wherein said identifying said at least one PLMN missed out during said first level search further comprises comparing results of said first level search with a reference database, by said PLMN selection module.
6) A User Equipment (UE) for performing reference data assisted Public Land Mobile Network (PLMN) search, said UE further configured for:
identifying at least one PLMN in said UE’s location as result of a first level of search, by a PLMN selection module present in said UE;
verifying said result of said first level of search by said PLMN selection module, wherein said verifying involves checking if said results cover all PLMNs in said location; and
performing a second level search by said PLMN selection module if said result of said first level search do not cover all PLMNs in said location, wherein said second level search identifies at least one PLMN missed out during said first level search.
7) The UE as claimed in claim 6, wherein said PLMN selection module is further configured for verifying said result of said first level search by:
identifying PLMN Id corresponding to said identified PLMN, using a scanning module; and
comparing said identified PLMN Id with a reference database using said scanning module, wherein said reference database possesses information on a plurality of PLMNs and PLMN Id corresponding each of said plurality of PLMNs, in said location.
8) The UE as claimed in claim 6, wherein said PLMN selection module is further configured for performing said second level search by:
identifying at least one PLMN missed out during said first level search, using a scanning module;
populating cells of said at least one PLMN, using said scanning module; and
searching for at least one valid cell among said populated cells using said scanning module, wherein said valid cell meets pre-configured criteria in terms of signal strength and type of services being handled.
9) The UE as claimed in claim 8, wherein said scanning module is further configured to identify said at least one PLMN missed out during said first level search by comparing results of said first level search with a reference database.

Date: 26 February 2015 Signature:
Kalyan Chakravarthy

ABSTRACT
Disclosed herein are a method and a User Equipment (UE) for reference data assisted Public Land Mobile Network (PLMN) search in a telecommunication network. The UE performs a first level search and identifies possible PLMN Id list in the UE’s location, as result of the first level search. Further the UE verifies the results and checks if the results have covered all PLMNs in that location based on reference data. If the results have not covered all PLMNs in that location, the UE performs a second level search and populates cells corresponding to channels being identified as missed in the results of the first level search. After identifying all channels, the UE identifies at least one valid cell, which can be used by the UE for availing services.
FIG. 1