Title of Invention	A METHOD OF PLMN SELECTION BY SIM CARD
Abstract	The present invention relates to the field of mobile communication. More specifically, the invention describes a amethod of network (PLMN) selection by a mobile device to give more control to the mobile network operatgor on the mobile device. The invention proposes a new set of proactive commands for the SIM card which can control the behavior of the mobile device related to network selection. To achieve this purpose, the operator will put appropriate logic in the SIM card to trigger the commands. A network selection algorithm is specified in the SIM through a set of commands. The SIM sends the specified commands to the mobile device for executing the algorithm of network selection.

Title of Invention

A METHOD OF PLMN SELECTION BY SIM CARD

Abstract

The present invention relates to the field of mobile communication. More specifically, the invention describes a amethod of network (PLMN) selection by a mobile device to give more control to the mobile network operatgor on the mobile device. The invention proposes a new set of proactive commands for the SIM card which can control the behavior of the mobile device related to network selection. To achieve this purpose, the operator will put appropriate logic in the SIM card to trigger the commands. A network selection algorithm is specified in the SIM through a set of commands. The SIM sends the specified commands to the mobile device for executing the algorithm of network selection.

Full Text	FIELD OF THE INVENTION The present invention relates to the field of Cellular Networks. The invention derives the new set of Proactive commands for a (U)SIM card which give more control to the cellular network operator on the UE. More particularly, the present invention relates to a method of PLMN Selection By SIM card. DESCRIPTION OF RELATED ART UE has to register on a PLMN to get services [except emergency calls]. The PLMN to which UE registers, is known as Registered PLMN (RPLMN). When UE is registered on a PLMN, the operator of the PLMN gets revenue when the UE uses the services. So operator would like the UE to be registered on his network as much as possible. The PLMN selection algorithms on the UE side are getting complex, because of shared networks, EPLMN's, Preferred PLMN's & increasing number of Radio access Technologies. With the growth of new Access Technologies & network sharing, There is need for the operators to have a proper PLMN selection algorithm on the UE side, which can increase there revenue as well as which can serve the Users with Best possible service. This complexity is reflected in UE's by having proprietary PLMN selection methods by different operators, and also the changes in the specifications to include improved methods of PLMN selection. LIMITATIONS There is no single practical PLMN Selection algorithm which is good for all the operators. That is the reason why Network operators add their own proprietary requirements on PLMN selection algorithms by UE. The UE has to support different PLMN selection algorithm if it were to work with Different Networks, which is very difficult for implementation. The UE does not guarantee that it will work as per the network operator's requirement for PLMN selection. There is no enough control for the operator to manage the PLMN selection algorithm on the UE side. It is difficult for the UE to change the PLMN selection algorithm dynamically. Hence there is a need for operators to dynamically control the PLMN selection by UE. The weaknesses in the existing art can be summarized as below 1) The UE's from open market does not guarantee that it will work as per Operator's proprietary PLMN selection algorithm 2) The network operator has less control over the PLMN selection algorithm by the UE. 3) It is time consuming for the UE vendor to implement different PLMN selection algorithm's for different operators. 4) UE does not have multiple PLMN selection algorithms since they add for the algorithm complexity & code size. SUMMARY OF THE INVENTION The invention is about, new set of proactive commands (proactive commands gives a mechanism whereby the (U)SIM can initiate actions to be taken by UE) which control the behaviour of the UE related to PLMN selection. Operator has to decide on when to make use of these primitives. The operator should put appropriate logic in (U) SIM cards which will trigger these commands & make the UE work as per operator's requirement. There are basically two kinds of commands, the first set of commands helps the (U) SIM card to collect information about the UE/networks, the second set of command changes the behaviour of the UE in some kind, The new proactive commands are explained below. 1) SELECT PLMN [MCC + MNC + RAT] 2) SEARCH NETWORK [2G 3G WLAN] 3) SEARCH HPLMN 4) CHANGE UE MODE [GSM,UMTS,WLAN,GSM_UMTS, GSM_WLAN, UMTS_WLAN, GSM_UMTS_WLAN etc] 5) CHANGE PLMN SELECT MODE [Automatic] 6) NEVER SEARCH PLMNS 7) GET_CURRENT_PLMN_SELECT_MODE Accordingly the invention explains a method of PLMN selection by SIM card wherein appropriate logic is incorporated in (U) SIM cards which trigger specific commands and make a UE work as per operator's requirement where two kinds of commands are introduced where the first set of commands helps the (U) SIM card to collect information about the UE/networks, the second set of command changes the behavior of the UE. These and other objects, features and advantages of the present invention will become more apparent from the ensuing detailed description of the invention taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS Figure 1 depicts the command SELECT PLMN Figure 2 depicts the command SEARCH NETWORK Figure 3 depicts the command SEARCH HPLMN Figure 4 depicts the command CHANGE UE MODE Figure 5 depicts the command NEVER SEARCH PLMNS Figure 6 depicts the command CHANGE PLMN SELECT MODE Figure 7 depicts the command GET CURRENT PLMN SELECT MODE Figure 8 depicts operator of PLMN A having a roaming agreement with PLMN B. Figure 9 depicts 3G coverage and 2G coverage network. Figure 10 depicts exchanges between ME and USIM card showing SELECT PLMN. Figure 11 depicts exchanges between ME and USIM card showing SEARCH NETWORK Figure 12 depicts exchanges between ME and USIM card showing NEVER SEARCH PLMNS DETAILED DESCRIPTION OF THE INVENTION The preferred embodiments of the present invention will now be explained with reference to the accompanying drawings. It should be understood however that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. The following description and drawings are not to be construed as limiting the invention and numerous specific details are described to provide a thorough understanding of the present invention, as the basis for the claims and as a basis for teaching one skilled in the art how to make and/or use the invention. However in certain instances, well-known or conventional details are not described in order not to unnecessarily obscure the present invention in detail. Detailed explanation of commands 1) SELECT PLMN [MCC + MNC + RAT] SIM shall give the MCC, MNC & the RAT in this command. UE shall try to camp & register to the given PLMN & RAT combination. One of the possible implementation of this command is given in fig 1. When UE is in connected mode, it shall not execute this command & instead shall send the failure code as "UE busy". If UE does not support the RAT, mentioned in the command, then UE shall reply with failure code "Beyond ME capabilities" If UE is in manual mode, then the failure shall be sent. While UE is in IDLE & is not in "Manual mode", the Terminal response shall be sent as Successful and the following actions shall be taken by the UE * The HPLMN/PPLMN search timer shall be paused. * The UE shall try to camp on the PLMN mentioned by the SIM card. The result of registration/camping shall not be sent to SIM card. * The HPLMN/PPLMN timer shall be restarted if required. The USIM card maintains 2 kinds of databases 1) list of PLMN id's, location area code and Radio Access Technology 2) The PLMN id, GPS co-ordinates x,y and the radius. This database is pre-computed and written on the sim card. The operator can modify the databases anytime through OTA e.g. in case of change in subscription. Two databases are provided since the location information can be given by 1) PLMN id , lai and cell id 2) PLMN id and GPS co¬ordinates. The GPS co-ordinates give the more accurate location information Database 1 MCC MNC LAc RAT Target PLMN RAT Xxx xxx xxx xxx xxxxxx xxx Database 2 MCC MNC LAC RAT X Y Inside/Outside Radius Target PLMN RAT Xxx xxx xxx xxx x x xx xx xx xx Scenario 1) consider operator of PLMN A having a roaming agreement with PLMN B. In some places the PLMN A and PLMN B may overlap in such cases the operator can write the PLMN id and the LAI of the PLMN B in database 1. and also the database 2 is polulated with the x, y co-ordinates where the PLMN A and PLMN B overlap. Scenario 2: The 3G networks are not deployed in all the places. The 2G network still provides the larger coverage area. Consider the scenario as shown in diagram above, wherein the 3G coverage is present in one small part and the 2G coverage is given in larger chunk. The mobiles in border area often experience the ping pong effect. To avoid the changing of network (2G-3G and 3G to 2G), the mobiles which are in border area can register to 2G network to avoid the ping pong. The network operator will update the second database as shown below. 222 123 XX 3G Xc Yc Rc Outside 222 123 2G what it means is, if the camped network is equal to 222,123 and 3G network. And if the user is in border area, then switch to 2G network. The Xc Yc and Rc help calculate whether the user is in border area or not. The parameter inside or outside helps to decide when the select PLMn sould be issues to ME. With the below sequence diagram, we try to illustrate the exchanges between ME and USIM card. Figure 10 depicts exchanges between ME and USIM card showing SELECT PLMN. af 2) SEARCH NETWORK [2G 3G WLAN] SIM shall provide the list of Access Technologies, in which the UE has to search for the PLMN's, optionally SIM card can also give the band information. One of the possible implementation of this command is given in fig 2. When UE is in connected mode, it shall not execute this command & instead shall send the failure code as "UE busy". If UE does not support the RAT, mentioned in the command, then UE shall reply with failure code "Beyond ME capabilities" If UE is in manual mode, then the failure shall be sent. With the advent of multimode handsets, the complexity for network search is increased. The tri-mode handsets which are capable of WLAN , GSM and WCDMA usually only search the GSM and WCDMA networks. Since the coverage of WLAN is very less, they are often not searched automatically. The decision to search the WLAN network is dependent on user. This patent provides an easy way wherein the search can be automated. The USIM card maintains the location (PLMN, LAC and cell id or the GPS co-ordinates wherein the WLAN hotspot is available). Whenever the ME does a sim write with the new location area identity. The USIM card checks if the WLAN hotspot is available in the area where user is currently located. And if yes, then the search for WLAN is triggered WLAN availability indicator Database 1 MCC MNC LAC cell Id Xxx xxx xxx xxx WLAN availability indicator Database 2 Xc Yc Rc Figure 11 depicts exchanges between ME and USIM card showing SEARCH NETWORK 3) SEARCH HPLMN [2G 3G WLAN] SIM shall provide the list of Access Technologies, in which the UE has to search for HPLMN only; optionally SIM card can also give the band information. One of the possible implementation of this command is given in fig 3. 4) CHANGE UE MODE [GSM, UMTS, WLAN, GSMJJMTS, GSM_WLAN, UMTS_WLAN, GSM_UMTS_WLAN etc] This command changes the mode of the UE, i.e. UE which is capable of GSM & UMTS, can be made as single mode GSM/UMTS or it can be made as dual mode GSM-UMTS. The UE shall change its mode, if it supports the given Access Technology; else UE shall send the failure to SIM card. One of the possible implementation of this command is given in fig 4. The subscription details of the user define whether he can use the 3G services or 2G services or both. If a user having a 2G subscription uses a dual mode handsets (2G and 3G). The handset will search for 3G network and waste the battery. Since the user may change his mobile handsets, the SIM card is the best hardware to carry this subscription details. A particular file in the sim card mentions the lists of Radio Access Technologies) which the user can use. The command "Change UE mode" will be issued at power on after sim initialization is complete. The change UE mode command will carry the parameters (GSM, UMTS, WLAN, GSMJJMTS, GSM_WLAN,UMTS_WLAN, GSMJJMTSJ/VLAN etc) 5) CHANGE PLMN SELECT MODE [Automatic] When UE is in manual mode of PLMN Selection, this command will change the UE mode to Automatic. One of the possible implementation of this command is given in fig 5. 6) NEVER SEARCH PLMNS The SIM card shall provide the PLMN's list, which UE shall never try to search. This may include the PLMN's which does not exists. One of the possible implementation of this command is given in fig 6. The USIM cards have the forbidden PLMN list length as 4. since there can be many PLMN which are forbidden, the length of 4 is not enough. Even if the length of forbidden PLMN list is increased, it is still not possible to update all the forbidden PLMN's. hence the forbidden PLMN list can be defined as per the country where the ME is in . e.g: if the ME is in India , it will get the list of forbidden PLMN in India. If ME is in US, it will receives the list of forbidden PLMN's in US. The USIM card can have databases of forbidden PLMN's for various countries. Once the ME updates the location area identity, the USIM card knows the country where the ME has come. The corresponding database will be sent to ME in the "NEVER SEARCH PLMN" command. INDIA FPLMN list (x,y,z) Sri Lanka FPLMN list (xx,xx,xx) Germany FPLMN list (xx.xx.xx) Figure 12 depicts exchanges between ME and USIM card showing NEVER SEARCH PLMNS 7) GET_CURRENT_PLMN_SELECT_MODE The UE shall respond to SIM card with the current PLMN selection mode (Automatic/Manual). One of the possible implementation of this command is given in fig 7. The below mentioned tables are referred from 3GPP TS 11.14. They are reproduced here with same section number for easy reference in the 3GPP specification. 13.2 BER-TLV tags in SIM TO ME direction Description Length of taq V«lu« Proactive SIM command taa 1 'DO1 12.6 Command details Byt»(«) Description Length i CommantJ details tag i 2 Lengfr = '03' 1 3 Command number 4 Type (tf command i 5 Command ouaWfer 1 Command details tag For contents and coding, see sub clause 11.14 section 6.5.1 (3GPP TS 11.14) Type of command Contents: The Type of Command specifies the required interpretation of the data objects which follow, and the required ME procedure. Coding: See section 13.4 The ME shall respond to reserved values (i.e. values not listed) with the result "Command type not understood". Command Qualifier: Contents: Qualifiers specific to the command. Coding: CHANGE UE MODE 8 7 6 5 4 3 2 1 \| \| \| GSM I \| UMTS \| WLAN 0 : indicates that corresponding Access technology is disabled 1 : Indicates that corresponding Access technology is Enabled Bits 4-8 RFU CHANGE PLMN SELECT MODE '00' = change the mode to automatic mode. '01' to 'FF' = reserved values. - SELECT PLMN This Byte is RFU. - SEARCH NETWORK This Byte is RFU. - SEARCH HPLMN This Byte is RFU. - NEVER SEARCH PLMNS This Byte is RFU. - GET CURRENT PLMN SELECT MODE This Byte is RFU. 12.7 Device identities Description Length Device identities 1 2 length = '02' 1 3 Source device identity 1 4 Donation Oevfce dentity 1 - source device identity Contents: the source device for information held in the data objects which follow. - Destination device identity Contents: the destination device for information held in the data objects which follow. NOTE: Only some combinations of Type of Command. Data Download type and Device identities arc allowed These are defined in clause 14. Coding: both Source and Destination device identities are coded as follows: - '01'* Keypad - '02' = Display - 'O.V= Earpiece - '\Vf to '17' = Additional Card Reader x (0 to Value assigned by ME. - '21' to'27'= Channel x fl to 1). Value assigned by ME (if class "e" is supported). - '81'-SIM - '82'« ME - '83'= Network All other values are reserved. 13.4 Type of Command and Next Action Indicator The table below shows ilw v aiues which shall be used tor Tyj)e of Command coding (see subclause 12.6> and Next Action Indicator cmhns Value Name used for Type of Command coding used lor Next Action Indicator coding W - ■or REFRESH X 02* MORE TME X T)3' POLL INTERVAL X T)4' POLLING OFF X T)5' SET UP EVENT LIST X ■to* SETUP CALL X X •ir SEND SS X X •\z SEND USSD X X '13' SEND SHORT1 MESSAGE X X '14' SEND DTMF X •15* LAUNCH BROWSER class "c" X '20' PLAY TONE X X ■21' DISPLAY TEXT X X '22 GET 1NKEY X X '23' GET INPUT X X '24' SELECT ITEM 1 X X '25' SETUP MENU X X '26' PftWiDE LOCAL INFbftMATiON X '27' TIMER MANAGEMENT X '28' SET UP'IDLE MODEL TEXT X X •30' PERFORM CARD APDU class "a' X X '31' POWER ON CARD class "a" X X •32* POWER OFF CARD class "a* X X •33' GET READER STATUS class 'a" X X ■34' fijNATiflMMAND class "b" X •35' LANGUAGE NoTlFlcATioN X '40- OPEN CHANNEL class e" X X '4t' CLOSE CHANNEL class V X X '42 RECEIVE DATA class V X X '43' SEND DATA class V X X '44' GET CHANNEL STATUS class "e" X X SO' Reserved for T1A/EIA-136 X X B1' End of the proactive session not applicable X Addition to Table 13.4 Value Name Used for Used for type of next command action coding indicator coding X SELECT PLMN X+1 SEARCH NETWORK X+2 SEARCH HPLMN X+3 CHANGE UE MODE X+4 NEVER SEARCH PLMNS X+5 CHANGE PLMN SELECT MODE X+6 GET CURRENT PLMN SELECT MODE 1) Coding of new items 6.1 PLMN Contents: Mobile Country code (MCC) followed by Mobile Network code (MNC) Coding: According to GSM 4.08 6.2 RAT Contents: Access Technology which MS will consider while searching/selecting a PLMN Coding: - 2 bytes are used to select the access technology where the meaning of each bit is as follows: - bit = 1: access technology selected; - bit = 0: access technology not selected. Byte 1: e8 1 fc7 be \| hi \| b r.e F.FV f.rj F.F'O F.rj "RFJ Reserved 3S T? 3: . 102 [52 • 1 Byte 2 fcg j fc7 j bt j c: \| b4 J \| fcl \| b F.F'J 'f.fv "F.fv 'f.f'.1 "f.f-J "asy. CC-OTA' "SSM RFU bits are coded as '0' 6.3 PLMN List Contents: List of PLMN's which UE shall not search for Coding: ADVANTAGES i) The Operator has more control on the PLMN selection algorithm of UE. ii) The Operator can make the UE to register on any other PLMN as required. iii) UE's performance related to PLMN selection is improved iv) Cost advantage for Operator as well as User. v) Since Operator can have the proprietary PLMN Selection algorithm in the SIM card, this will reduce the time to market. vi) The PLMN selection algorithm can be made independent of UE vendor's implementation to some extent. It will also be obvious to those skilled in the art that other control methods and apparatuses can be derived from the combinations of the various methods and apparatuses of the present invention as taught by the description and the accompanying drawings and these shall also be considered within the scope of the present invention. Further, description of such combinations and variations is therefore omitted above. It should also be noted that the host for storing the applications include but not limited to a microchip, microprocessor, handheld communication device, computer, rendering device or a multi function device. Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are possible and are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart there from. GLOSSARY OF TERMS AND DEFINITIONS THEREOF EF - Elementary file IMEI - International Mobile Equipment identity IMSI - International Mobile subscriber identity ME - Mobile Equipment OTA - Over The Air SAT - SIM application toolkit SIM - Subscriber Identity Module UE - User Equipment J- - 'y We Claim: 1. A method of PLMN selection by SIM card wherein appropriate logic is incorporated in (U) SIM cards which trigger specific commands and make a UE work as per operator's requirement where two kinds of commands are introduced where the first set of commands helps the (U) SIM card to collect information about the UE/networks, the second set of command changes the behavior of the UE. 2. The method as claimed in claim 1 wherein, the operator put appropriate logic in the SIM to trigger the commands. 3. The method as claimed in claim 1 wherein a network selection algorithm is specified in the SIM through a set of commands and the SIM sends the specified commands to the mobile device for executing the algorithm of network selection. 4. The method as claimed in claim 1 wherein the said command include the command SELECT PLMN where the SIM give the MCC, MNC & the RAT in the said command and the UE try to camp and register to the given PLMN and RAT combination. 5. The method as claimed in claim 1 wherein the said command include the command SEARCH NETWORK where the SIM provide the list of Access Technologies, in which the UE has to search for the PLMN's, and optionally SIM is adapted to give the band information. 6. The method as claimed in claim 1 wherein the said command include the command SEARCH HPLMN and where SIM provide the list of Access Technologies, in which the UE has to search for HPLMN only and optionally SIM is adapted to give the band information. 7. The method as claimed in claim 1 wherein the said command include the command CHANGE UE MODE where the said command changes mode of the UE, if the UE supports the given Access Technology or else send the failure to SIM. 8. The method as claimed in claim 1 wherein the said command include the command CHANGE PLMN SELECT MODE wherein when UE is in manual mode of PLMN Selection, the said command change the UE mode to Automatic. 9. The method as claimed in claim 1 wherein the said command include the command NEVER SEARCH PLMNS where the SIM provide the PLMN's list, which UE shall never try to search which include the PLMN's which does not exists. 10. The method as claimed in claim 1 wherein the said command include the command GET_CURRENT_PLMN_SELECT_MODE where the UE respond to SIM card with the current PLMN selection mode (Automatic/Manual). 11. A method of PLMN selection by SIM card substantially described particularly with reference to the accompanying drawings.

Full Text

FIELD OF THE INVENTION
The present invention relates to the field of Cellular Networks. The invention derives the new set of Proactive commands for a (U)SIM card which give more control to the cellular network operator on the UE. More particularly, the present invention relates to a method of PLMN Selection By SIM card.
DESCRIPTION OF RELATED ART
UE has to register on a PLMN to get services [except emergency calls]. The PLMN to which UE registers, is known as Registered PLMN (RPLMN). When UE is registered on a PLMN, the operator of the PLMN gets revenue when the UE uses the services. So operator would like the UE to be registered on his network as much as possible. The PLMN selection algorithms on the UE side are getting complex, because of shared networks, EPLMN's, Preferred PLMN's & increasing number of Radio access Technologies. With the growth of new Access Technologies & network sharing, There is need for the operators to have a proper PLMN selection algorithm on the UE side, which can increase there revenue as well as which can serve the Users with Best possible service. This complexity is reflected in UE's by having proprietary PLMN selection methods by different operators, and also the changes in the specifications to include improved methods of PLMN selection.
LIMITATIONS
There is no single practical PLMN Selection algorithm which is good for all the operators. That is the reason why Network operators add their own proprietary requirements on PLMN selection algorithms by UE. The UE has to support different PLMN selection algorithm if it were to work with Different Networks, which is very difficult for implementation. The UE does not guarantee that it will work as per the network operator's requirement for PLMN selection. There is no enough control for the operator to manage the PLMN selection algorithm on the UE side. It is difficult for the UE to change the PLMN selection algorithm dynamically. Hence there is a need for operators to dynamically control the PLMN selection by UE.
The weaknesses in the existing art can be summarized as below
1) The UE's from open market does not guarantee that it will work as per Operator's proprietary PLMN selection algorithm
2) The network operator has less control over the PLMN selection algorithm by the UE.
3) It is time consuming for the UE vendor to implement different PLMN selection algorithm's for different operators.
4) UE does not have multiple PLMN selection algorithms since they add for the algorithm complexity & code size.
SUMMARY OF THE INVENTION
The invention is about, new set of proactive commands (proactive commands gives a mechanism whereby the (U)SIM can initiate actions to be taken by UE) which control the behaviour of the UE related to PLMN selection. Operator has to decide on when to make use of these primitives. The operator should put appropriate logic in (U) SIM cards which will trigger these commands & make the UE work as per operator's requirement. There are basically two kinds of commands, the first set of commands helps the (U) SIM card to collect information about the UE/networks, the second set of command changes the behaviour of the UE in some kind, The new proactive commands are explained below.
1) SELECT PLMN [MCC + MNC + RAT]
2) SEARCH NETWORK [2G 3G WLAN]
3) SEARCH HPLMN
4) CHANGE UE MODE [GSM,UMTS,WLAN,GSM_UMTS, GSM_WLAN, UMTS_WLAN, GSM_UMTS_WLAN etc]
5) CHANGE PLMN SELECT MODE [Automatic]
6) NEVER SEARCH PLMNS
7) GET_CURRENT_PLMN_SELECT_MODE
Accordingly the invention explains a method of PLMN selection by SIM card wherein appropriate logic is incorporated in (U) SIM cards which trigger specific commands and make a UE work as per operator's requirement where two kinds of commands are introduced where the first set of commands helps the (U) SIM card to collect information about the UE/networks, the second set of command changes the behavior of the UE.
These and other objects, features and advantages of the present invention will become more apparent from the ensuing detailed description of the invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
Figure 1 depicts the command SELECT PLMN
Figure 2 depicts the command SEARCH NETWORK
Figure 3 depicts the command SEARCH HPLMN
Figure 4 depicts the command CHANGE UE MODE
Figure 5 depicts the command NEVER SEARCH PLMNS
Figure 6 depicts the command CHANGE PLMN SELECT MODE
Figure 7 depicts the command GET CURRENT PLMN SELECT MODE
Figure 8 depicts operator of PLMN A having a roaming agreement with
PLMN B.
Figure 9 depicts 3G coverage and 2G coverage network.
Figure 10 depicts exchanges between ME and USIM card showing
SELECT PLMN.
Figure 11 depicts exchanges between ME and USIM card showing SEARCH NETWORK
Figure 12 depicts exchanges between ME and USIM card showing NEVER SEARCH PLMNS
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiments of the present invention will now be explained with reference to the accompanying drawings. It should be understood however that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. The following description and drawings are not to be construed as limiting the invention and numerous specific details are described to provide a thorough understanding of the present invention, as the basis for the claims and as a basis for teaching one skilled in the art how to make and/or use the invention. However in certain instances, well-known or conventional details are not described in order not to unnecessarily obscure the present invention in detail.
Detailed explanation of commands 1) SELECT PLMN [MCC + MNC + RAT]
SIM shall give the MCC, MNC & the RAT in this command. UE shall try to camp & register to the given PLMN & RAT combination. One of the possible implementation of this command is given in fig 1.
When UE is in connected mode, it shall not execute this command & instead shall send the failure code as "UE busy".
If UE does not support the RAT, mentioned in the command, then UE shall reply with failure code "Beyond ME capabilities" If UE is in manual mode, then the failure shall be sent.
While UE is in IDLE & is not in "Manual mode", the Terminal response shall be sent as Successful and the following actions shall be taken by the UE
* The HPLMN/PPLMN search timer shall be paused.
* The UE shall try to camp on the PLMN mentioned by the SIM card. The result of registration/camping shall not be sent to SIM card.
* The HPLMN/PPLMN timer shall be restarted if required.
The USIM card maintains 2 kinds of databases
1) list of PLMN id's, location area code and Radio Access Technology
2) The PLMN id, GPS co-ordinates x,y and the radius.
This database is pre-computed and written on the sim card. The operator can modify the databases anytime through OTA e.g. in case of change in subscription. Two databases are provided since the location information can be given by 1) PLMN id , lai and cell id 2) PLMN id and GPS co¬ordinates. The GPS co-ordinates give the more accurate location information
Database 1
MCC MNC LAc RAT Target PLMN RAT Xxx xxx xxx xxx xxxxxx xxx
Database 2
MCC MNC LAC RAT X Y Inside/Outside Radius Target PLMN RAT Xxx xxx xxx xxx x x xx xx xx xx
Scenario 1)
consider operator of PLMN A having a roaming agreement with PLMN B. In some places the PLMN A and PLMN B may overlap in such cases the operator can write the PLMN id and the LAI of the PLMN B in database 1. and also the database 2 is polulated with the x, y co-ordinates where the PLMN A and PLMN B overlap.
Scenario 2:
The 3G networks are not deployed in all the places. The 2G network still provides the larger coverage area. Consider the scenario as shown in diagram above, wherein the 3G coverage is present in one small part and the 2G coverage is given in larger chunk. The mobiles in border area often experience the ping pong effect. To avoid the changing of network (2G-3G and 3G to 2G), the mobiles which are in border area can register to 2G network to avoid the ping pong. The network operator will update the second database as shown below.
222 123 XX 3G Xc Yc Rc Outside 222 123 2G
what it means is, if the camped network is equal to 222,123 and 3G network. And if the user is in border area, then switch to 2G network. The Xc Yc and Rc help calculate whether the user is in border area or not. The parameter inside or outside helps to decide when the select PLMn sould be issues to ME.
With the below sequence diagram, we try to illustrate the exchanges between ME and USIM card.
Figure 10 depicts exchanges between ME and USIM card showing SELECT PLMN.
af
2) SEARCH NETWORK [2G 3G WLAN]
SIM shall provide the list of Access Technologies, in which the UE has to search for the PLMN's, optionally SIM card can also give the band information. One of the possible implementation of this command is given in fig 2.
When UE is in connected mode, it shall not execute this command & instead shall send the failure code as "UE busy". If UE does not support the RAT, mentioned in the command, then UE shall reply with failure code "Beyond ME capabilities"
If UE is in manual mode, then the failure shall be sent.
With the advent of multimode handsets, the complexity for network search is increased. The tri-mode handsets which are capable of WLAN , GSM and WCDMA usually only search the GSM and WCDMA networks. Since the coverage of WLAN is very less, they are often not searched automatically. The decision to search the WLAN network is dependent on user. This patent provides an easy way wherein the search can be automated.
The USIM card maintains the location (PLMN, LAC and cell id or the GPS co-ordinates wherein the WLAN hotspot is available). Whenever the ME
does a sim write with the new location area identity. The USIM card checks if the WLAN hotspot is available in the area where user is currently located. And if yes, then the search for WLAN is triggered
WLAN availability indicator Database 1 MCC MNC LAC cell Id Xxx xxx xxx xxx
WLAN availability indicator Database 2 Xc Yc Rc
Figure 11 depicts exchanges between ME and USIM card showing SEARCH NETWORK
3) SEARCH HPLMN [2G 3G WLAN]
SIM shall provide the list of Access Technologies, in which the UE has to search for HPLMN only; optionally SIM card can also give the band information. One of the possible implementation of this command is given in fig 3.
4) CHANGE UE MODE [GSM, UMTS, WLAN, GSMJJMTS, GSM_WLAN, UMTS_WLAN, GSM_UMTS_WLAN etc]
This command changes the mode of the UE, i.e. UE which is capable of
GSM & UMTS, can be made as single mode GSM/UMTS or it can be made as dual mode GSM-UMTS. The UE shall change its mode, if it supports the given Access Technology; else UE shall send the failure to SIM card. One of the possible implementation of this command is given in fig 4.
The subscription details of the user define whether he can use the 3G services or 2G services or both. If a user having a 2G subscription uses a dual mode handsets (2G and 3G). The handset will search for 3G network and waste the battery. Since the user may change his mobile handsets, the SIM card is the best hardware to carry this subscription details. A particular file in the sim card mentions the lists of Radio Access Technologies) which the user can use. The command "Change UE mode" will be issued at power on after sim initialization is complete. The change UE mode command will carry the parameters (GSM, UMTS, WLAN, GSMJJMTS, GSM_WLAN,UMTS_WLAN, GSMJJMTSJ/VLAN etc)
5) CHANGE PLMN SELECT MODE [Automatic]
When UE is in manual mode of PLMN Selection, this command will change the UE mode to Automatic. One of the possible implementation of this command is given in fig 5.
6) NEVER SEARCH PLMNS
The SIM card shall provide the PLMN's list, which UE shall never try to search. This may include the PLMN's which does not exists. One of the possible implementation of this command is given in fig 6.
The USIM cards have the forbidden PLMN list length as 4. since there can be many PLMN which are forbidden, the length of 4 is not enough. Even if the length of forbidden PLMN list is increased, it is still not possible to update all the forbidden PLMN's. hence the forbidden PLMN list can be defined as per the country where the ME is in . e.g: if the ME is in India , it will get the list of forbidden PLMN in India. If ME is in US, it will receives the list of forbidden PLMN's in US.
The USIM card can have databases of forbidden PLMN's for various countries. Once the ME updates the location area identity, the USIM card knows the country where the ME has come. The corresponding database will be sent to ME in the "NEVER SEARCH PLMN" command.
INDIA FPLMN list (x,y,z) Sri Lanka FPLMN list (xx,xx,xx) Germany FPLMN list (xx.xx.xx)
Figure 12 depicts exchanges between ME and USIM card showing NEVER SEARCH PLMNS
7) GET_CURRENT_PLMN_SELECT_MODE
The UE shall respond to SIM card with the current PLMN selection mode (Automatic/Manual). One of the possible implementation of this command is given in fig 7.
The below mentioned tables are referred from 3GPP TS 11.14. They are reproduced here with same section number for easy reference in the 3GPP specification.
13.2 BER-TLV tags in SIM TO ME direction
Description Length of taq V«lu«
Proactive SIM command taa 1 'DO1

12.6 Command details
Byt»(«) Description Length
i CommantJ details tag i
2 Lengfr = '03' 1
3 Command number
4 Type (tf command i
5 Command ouaWfer 1

Command details tag
For contents and coding, see sub clause 11.14 section 6.5.1 (3GPP TS 11.14)
Type of command
Contents: The Type of Command specifies the required interpretation of the data objects which follow, and the required ME procedure.
Coding:
See section 13.4
The ME shall respond to reserved values (i.e. values not listed) with the result "Command type not understood".
Command Qualifier:
Contents: Qualifiers specific to the command. Coding:
CHANGE UE MODE
8 7 6 5 4 3 2 1
| | | GSM
I | UMTS
| WLAN
0 : indicates that corresponding Access technology is disabled
1 : Indicates that corresponding Access technology is Enabled Bits 4-8 RFU
CHANGE PLMN SELECT MODE
'00' = change the mode to automatic mode.
'01' to 'FF' = reserved values.
- SELECT PLMN This Byte is RFU.
- SEARCH NETWORK This Byte is RFU.
- SEARCH HPLMN This Byte is RFU.
- NEVER SEARCH PLMNS This Byte is RFU.
- GET CURRENT PLMN SELECT MODE
This Byte is RFU.
12.7 Device identities
Description Length
Device identities 1
2 length = '02' 1
3 Source device identity 1
4 Donation Oevfce dentity 1

- source device identity
Contents: the source device for information held in the data objects which follow.
- Destination device identity
Contents: the destination device for information held in the data objects which follow.
NOTE: Only some combinations of Type of Command. Data Download type and Device identities arc allowed These are defined in clause 14.
Coding: both Source and Destination device identities are coded as follows:
- '01'* Keypad
- '02' = Display
- 'O.V= Earpiece
- '\Vf to '17' = Additional Card Reader x (0 to Value assigned by ME.
- '21' to'27'= Channel x fl to 1). Value assigned by ME (if class "e" is supported).
- '81'-SIM
- '82'« ME
- '83'= Network
All other values are reserved.
13.4 Type of Command and Next Action Indicator
The table below shows ilw v aiues which shall be used tor Tyj)e of Command coding (see subclause 12.6> and Next Action Indicator cmhns Value Name used for Type of Command coding used lor Next Action Indicator coding
W -
■or REFRESH X
02* MORE TME X
T)3' POLL INTERVAL X
T)4' POLLING OFF X
T)5' SET UP EVENT LIST X
■to* SETUP CALL X X
•ir SEND SS X X
•\z SEND USSD X X
'13' SEND SHORT1 MESSAGE X X
'14' SEND DTMF X
•15* LAUNCH BROWSER class "c" X
'20' PLAY TONE X X
■21' DISPLAY TEXT X X
'22 GET 1NKEY X X
'23' GET INPUT X X
'24' SELECT ITEM 1 X X
'25' SETUP MENU X X
'26' PftWiDE LOCAL INFbftMATiON X
'27' TIMER MANAGEMENT X
'28' SET UP'IDLE MODEL TEXT X X
•30' PERFORM CARD APDU class "a' X X
'31' POWER ON CARD class "a" X X
•32* POWER OFF CARD class "a* X X
•33' GET READER STATUS class 'a" X X
■34' fijNATiflMMAND class "b" X
•35' LANGUAGE NoTlFlcATioN X
'40- OPEN CHANNEL class *e" X X
'4t' CLOSE CHANNEL class V X X
'42* RECEIVE DATA class V X X
'43' SEND DATA class V X X
'44' GET CHANNEL STATUS class "e" X X
SO' Reserved for T1A/EIA-136 X X
B1' End of the proactive session not applicable X

Addition to Table 13.4
Value Name Used for Used for
type of next
command action
coding indicator
coding

X SELECT PLMN
X+1 SEARCH NETWORK
X+2 SEARCH HPLMN
X+3 CHANGE UE MODE
X+4 NEVER
SEARCH
PLMNS
X+5 CHANGE PLMN SELECT MODE
X+6 GET
CURRENT PLMN SELECT MODE

1) Coding of new items
6.1 PLMN
Contents: Mobile Country code (MCC) followed by Mobile Network code (MNC)
Coding: According to GSM 4.08
6.2 RAT
Contents: Access Technology which MS will consider while
searching/selecting a PLMN
Coding:
- 2 bytes are used to select the access technology where the meaning of each bit is as follows:
- bit = 1: access technology selected;
- bit = 0: access technology not selected.
Byte 1:
e8 1 fc7 be | hi | b
r.e
F.FV
f.rj
F.F'O F.rj "RFJ
Reserved 3S T? 3: . 102 [52 • 1
Byte 2
fcg j fc7 j bt j c: | b4 J | fcl | b
F.F'J 'f.fv "F.fv
'f.f'.1 "f.f-J
"asy. CC-OTA'
"SSM
RFU bits are coded as '0'
6.3 PLMN List
Contents: List of PLMN's which UE shall not search for Coding:
ADVANTAGES
i) The Operator has more control on the PLMN selection algorithm of UE.
ii) The Operator can make the UE to register on any other PLMN as required.
iii) UE's performance related to PLMN selection is improved
iv) Cost advantage for Operator as well as User.
v) Since Operator can have the proprietary PLMN Selection algorithm in the SIM card, this will reduce the time to market.
vi) The PLMN selection algorithm can be made independent of UE vendor's implementation to some extent.
It will also be obvious to those skilled in the art that other control methods and apparatuses can be derived from the combinations of the various methods and apparatuses of the present invention as taught by the description and the accompanying drawings and these shall also be considered within the scope of the present invention. Further, description of such combinations and variations is therefore omitted above. It should also be noted that the host for storing the applications include but not limited to a microchip, microprocessor, handheld communication device, computer, rendering device or a multi function device.
Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are possible and are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart there from.
GLOSSARY OF TERMS AND DEFINITIONS THEREOF
EF - Elementary file
IMEI - International Mobile Equipment identity
IMSI - International Mobile subscriber identity
ME - Mobile Equipment
OTA - Over The Air
SAT - SIM application toolkit
SIM - Subscriber Identity Module
UE - User Equipment

J- -
'y We Claim:
1. A method of PLMN selection by SIM card wherein appropriate logic is incorporated in (U) SIM cards which trigger specific commands and make a UE work as per operator's requirement where two kinds of commands are introduced where the first set of commands helps the (U) SIM card to collect information about the UE/networks, the second set of command changes the behavior of the UE.
2. The method as claimed in claim 1 wherein, the operator put appropriate logic in the SIM to trigger the commands.
3. The method as claimed in claim 1 wherein a network selection algorithm is specified in the SIM through a set of commands and the SIM sends the specified commands to the mobile device for executing the algorithm of network selection.
4. The method as claimed in claim 1 wherein the said command include the command SELECT PLMN where the SIM give the MCC, MNC & the RAT in the said command and the UE try to camp and register to the given PLMN and RAT combination.
5. The method as claimed in claim 1 wherein the said command include the command SEARCH NETWORK where the SIM provide the list of Access Technologies, in which the UE has to search for the PLMN's, and optionally SIM is adapted to give the band information.
6. The method as claimed in claim 1 wherein the said command include the command SEARCH HPLMN and where SIM provide the list of Access Technologies, in which the UE has to search for HPLMN only and optionally SIM is adapted to give the band information.
7. The method as claimed in claim 1 wherein the said command include the command CHANGE UE MODE where the said command changes mode of the UE, if the UE supports the given Access Technology or else send the failure to SIM.
8. The method as claimed in claim 1 wherein the said command include the command CHANGE PLMN SELECT MODE wherein when UE is in manual mode of PLMN Selection, the said command change the UE mode to Automatic.
9. The method as claimed in claim 1 wherein the said command include the command NEVER SEARCH PLMNS where the SIM provide the PLMN's list, which UE shall never try to search which include the PLMN's which does not exists.
10. The method as claimed in claim 1 wherein the said command include the command GET_CURRENT_PLMN_SELECT_MODE where the UE respond to SIM card with the current PLMN selection mode (Automatic/Manual).
11. A method of PLMN selection by SIM card substantially described particularly with reference to the accompanying drawings.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=A+C0MVhIM1rIncBl8BhCCQ==&loc=egcICQiyoj82NGgGrC5ChA==

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Patent Number

279284

Indian Patent Application Number

2491/CHE/2006

PG Journal Number

03/2017

Publication Date

20-Jan-2017

Grant Date

17-Jan-2017

Date of Filing

29-Dec-2006

Name of Patentee

SAMSUNG R& D INSTITUTE INDIA BANGALORE PRIVATE LIMITED

Applicant Address

#2870 ORION BUILDING BAGMANE CONSTELLATION BUSINESS PARK OUTER RING ROAD DODDANEKUNDI CIRCLE MARATHAHALLI POST BANGALORE -560037

Inventors:

#	Inventor's Name	Inventor's Address
1	SOMASHEKAR VISHWANTH RUDRAKSHI	EMPLOYED AT SAMSUNG INDIA SOFTWARE OPERATIONS PVT LTD HAVING ITS OFFICE AT BAGMANE LAKEVIEW BLOCK 'B' NO 66/1 BAGMANE TECH PARK C V RAMAN NAGAR BYRASANDRA BANGALORE-560093 KARNATAKA INDIA

PCT International Classification Number

H04B1/38

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA