(19) United States (12) Patent Application Publication (10) Pub

US 20140011497A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2014/0011497 A1 Vashi et al. (43) Pub. Date: Jan. 9, 2014

(54) MOBILE DEVICE WHICH DELETES (52) US. Cl. DUPLICATE PREFERRED ROAMING LIST CPC ...... H04 W8/00 (2013.01); H04 W88/02 SYSTEM RECORDS FOR IMPROVED (201301) PERFORMANCE USPC ...... 455/4321; 455/5751 (71) Applicant: APPLE INC., Cupertino, CA (US) (72) Inventors: Prashant H. Vashi, Sunnyvale, CA (57) ABSTRACT (US); Vikram B. Yerrabommanahalli, Sunnyvale, CA (US); Karthik Anantharaman, Sunnyvale, CA (US) A User Equipment (UE) device and associated method for operating a User Equipment (UE) in a Wireless communica (73) Assignee: APPLE INC., Cupertino, CA (US) tion system. The UE may store a preferred roaming list in a memory. The preferred roaming list may comprise a plurality (21) Appl.N0.: 13/678,701 of system records Which specify radio access technologies (22) Filed: Nov. 16, 2012 that can be used by the UE. The UE may examine the pre ferred roaming list to delete any duplicate system records in Related US. Application Data the PRL for respective geographic locations (GEOs). This may operate to mitigate the problems created by duplicate (60) Provisional application No. 61/668,957, ?led on Jul. 6, listing of system records Within the PRL. In particular, the 2012. removal of redundant system records Within the PRL may Publication Classi?cation reduce or eliminate unneeded or undesired BSR algorithm execution. In addition, the removal of redundant system (51) Int. Cl. records Within the PRL may reduce temporal service outages, H04W 8/00 (2006.01) since no service origination is alloWed While the UE is H04W 88/02 (2006.01) attempting to ?nd the most preferred system.

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US 2014/0011497 A1 Jan. 9, 2014

MOBILE DEVICE WHICH DELETES and other supplementary services for their subscribers When DUPLICATE PREFERRED ROAMING LIST they travel internationally. Roaming agreements can be With SYSTEM RECORDS FOR IMPROVED operators that use the same underlying radio access technol PERFORMANCE ogy or a different technology. For example, a 3GPP2 (Third Generation Partnership Project 2) operator can have roaming PRIORITY CLAIM relationships With other 3GPP2 operators or 3GPP operators. [0001] The present application claims bene?t of priority to [0008] The term “Multi-Mode System Selection” (MMSS) US. Provisional Application No. 61/668,957 titled “Mobile refers to an algorithm that a multimode device utiliZes to Device Which Deletes Duplicate Preferred Roaming List select the radio access technology (RAT) it should use for System Records for Improved Performance” and ?led on Jul. services in any particular region. In some Wireless commu 6, 2012, Whose inventors are Prashant H. Vashi, Vikram B. nication systems, multimode system selection (MMSS) pro Yerrabommanahalli, and Karthik Anantharaman, and Which vides a user equipment (UE) device the ability to select the is hereby incorporated by reference in its entirety as thought best possible RAT (also referred to as “telecommunication fully and completely set forth herein. standar ”) in a given area. For example, MMSS enables a UE to select the most preferred RAT for accessing different ser FIELD vices among both 3GPP and 3GPP2 systems. [0009] Mobile devices store a roaming list, referred to as [0002] The present invention relates generally to Wireless the PRL (Preferred Roaming List), used to select the appro devices, and more particularly to performance improvement priate RAT for a given geographic region (GEO). The PRL strategies for devices that roam on Wireless netWorks. stores one or more (typically a plurality of) system records for each geographic region, Where each system record identi?es DESCRIPTION OF THE RELATED ART a respective RAT that may be used by the mobile device in a [0003] Wireless communication systems are rapidly groW respective GEO. ing in usage. Further, Wireless communication technology [0010] The goal of the PRL is to help the UE ?nd the most has evolved from voice-only communications to also include preferred RAT (or telecommunication standard) Within a the transmission of data, such as Internet and multimedia GEO and utiliZe that RAT for accessing different services. If content. Therefore, improvements are desired in Wireless the UE cannot ?nd the most preferred RAT Within a GEO, it communication. camps on the next available preferred system for accessing [0004] Wireless network operators can deploy neW radio services. HoWever, the UE uses What is called Better System access technologies in parallel With earlier generation radio Re-selection (BSR) algorithm to try the ?nd the most pre ferred (or a more preferred) system When it is camped on a access technologies, and Wireless netWorks can support mul tiple radio access technologies simultaneously to provide less preferred system. smooth transitions through multiple generations of mobile [0011] HoWever, in some instances the PRL might contain Wireless devices. For example, a representative Wireless net duplicate system records. As one example of this, the con Work can include simultaneous support for the Third Genera struction of one type of PRL (the EqPRL) is based on input tion Partnership Project (3GPP) Long Term Evolution (LTE) from many ?les Which are not controlled by the UE, but rather Wireless communication protocol and the Third Generation are controlled by the Wireless operators. Thus there is a Partnership Project 2 (3GPP2) CDMA2000 1x (also referred chance that a system might be listed as the most preferred system as Well as a less preferred system Within the same to as 1xRTT or 1x) Wireless communication protocol. This exemplary “simultaneous” Wireless netWork can support cir GEO. For example, a system record may end up being listed cuit sWitched voice connections through a ?rst Wireless net tWice Within the same GEO due to a change in structure/ content of some ?les by the Wireless operator(s). These Work that uses the CDMA2000 1x Wireless communication protocol and packet sWitched connections (voice or data) changes are generally governed by forthcoming roaming relationships or other changes Within a Wireless operator’s s through a second Wireless netWork that uses the LTE Wireless communication protocol. service offerings. [0005] The 3GPP Wireless communications standards [0012] This duplicate listing of systems Will trigger the UE organization develops mobile communication standards that to execute the BSR algorithm and ?nd the most preferred include releases for Global System for Mobile Communica system even though it is already camped on the most pre tions (GSM), General Packet Radio Service (GPRS), Univer ferred system. This behavior is referred to herein as “System sal Mobile Telecommunications System (U MTS), Long Selection loops”. System Selection loops cause unnecessary Term Evolution (LTE) and LTE Advanced standards. The battery drain and also a temporal service outage. Battery drain 3GPP2 Wireless communications standards organization is caused by the fact that the UE Will try to ?nd the most develops mobile communication standards that include preferred system once every x seconds, even though there is no need for it to do so. Temporal service outage is caused due CDMA2000 1xRTT and lxEV-DO standards. to the fact no service origination is alloWed While the UE is [0006] Multimode UE devices may refer to UE devices that trying to ?nd the most preferred system. are compatible With a plurality of radio access technologies (RATs) or telecommunication standards. Multimode mobile [0013] Therefore, improvements are desired in the MMSS Wireless devices may include separate signal processing operation of Wireless devices. chips that each can support a different RAT, such as one signal processing chip for the CDMA2000 1x Wireless netWork and SUMMARY another signal processing chip for the LTE Wireless netWork. [0014] Embodiments of the invention relate to a User [0007] Wireless operators, such as AT&T, Sprint, VeriZon, Equipment (UE) device and associated method for operating Orange, etc. typically have roaming relationships With opera a UE in a Wireless communication system. In one embodi tors in different countries to enable accessibility of voice, data ment, the UE may store a preferred roaming list in a memory. US 2014/0011497 A1 Jan. 9, 2014

The preferred roaming list may comprise a plurality of system DETAILED DESCRIPTION OF THE records which specify radio access technologies (RATs) that EMBODIMENTS can be used by the UE. The UE may then examine the pre ferred roaming list to determine if any duplicate system Acronyms records exist in the preferred roaming list for respective geo graphic locations (GEOs). If the UE determines that one or [0026] The following acronyms are used in the present more duplicate system records exist in the preferred roaming Provisional Patent Application. list for a GEO, the UE deletes the duplicate system record(s) [0027] 3GPP: Third Generation Partnership Project from the preferred roaming list for that GEO. The UE pref [0028] 3GPP2: Third Generation Partnership Project 2 erably deletes a less preferred duplicate system record from [0029] BTS: Base Transceiver System the preferred roaming list for the respective GEO. [0030] HRPD: High Rate Packet Data [0015] In one embodiment, the UE examines the preferred [0031] eHRPD: Evolved High Rate Packet Data roaming list and deletes any duplicate system records during [0032] EPC: Evolved Packet Core creation of the preferred roaming list. In another embodi [0033] eqPRL: Equivalent PRL ment, the UE examines the preferred roaming list and deletes [0034] MMSS: Multimode System Selection any duplicate system records at predetermined intervals, e.g., whenever the UE examines the preferred roaming list for [0035] MLPL: MMSS Location Associated Priority List radio access technology selection. (MLPL) [0016] Thus, embodiments of the invention operate to [0036] MSPL: MMSS System Priority List remove redundant system records within the preferred roam [0037] PRL: Preferred Roaming List ing list (PRL). This may operate to mitigate the problems [0038] RAT: Radio Access Technology created by duplicate listing of system records within the same [0039] UE: User Equipment GEO. In particular, the removal of redundant system records [0040] UMTS: Universal Mobile Telecommunications within the PRL may operate to reduce or eliminate unneeded System or undesired BSR algorithm execution, i.e., System Selection [0041] LTE: Long Term Evolution Loops. In addition, the removal of redundant system records within the PRL may operate to reduce temporal service out Terms ages caused by the fact that no service origination is allowed while the UE is attempting to ?nd the most preferred system. [0042] The following is a glossary of terms used in the present application: BRIEF DESCRIPTION OF THE DRAWINGS [0043] Memory MediumiAny of various types of [0017] A better understanding of the present embodiments memory devices or storage devices. The term “memory can be obtained when the following detailed description of medium” is intended to include an installation medium, e. g., the preferred embodiment is considered in conjunction with a CD-ROM, ?oppy disks, or tape device; a computer system the following drawings, in which: memory or random access memory such as DRAM, DDR [0018] FIG. 1 illustrates an exemplary (and simpli?ed) RAM, SRAM, EDO RAM, Rambus RAM, etc.; a non-vola wireless communication system according to one embodi tile memory such as a Flash, magnetic media, e.g., a hard ment; drive, or optical storage; registers, or other similar types of [0019] FIG. 2 illustrates a base station in communication memory elements, etc. The memory medium may include with user equipment according to one embodiment; other types of memory as well or combinations thereof. In [0020] FIG. 3 illustrates an exemplary block diagram of a addition, the memory medium may be located in a ?rst com user equipment device, according to one embodiment; puter in which the programs are executed, or may be located [0021] FIG. 4 is a ?owchart of a method for operating a user in a second different computer which connects to the ?rst equipment device which removes duplicate system records computer over a network, such as the Internet. In the latter from the preferred roaming list; instance, the second computer may provide program instruc [0022] FIG. 5 is a ?owchart illustrating determination and tions to the ?rst computer for execution. The term “memory deletion of duplicate system records in the preferred roaming medium” may include two or more memory mediums which list during creation of the PRL; may reside in different locations, e. g., in different computers [0023] FIG. 6 is a ?owchart illustrating determination and that are connected over a network. The memory medium may deletion of duplicate system records in the preferred roaming store program instructions (e.g., embodied as computer pro list during system selection; and grams) that may be executed by one or more processors. [0024] FIG. 7 illustrates an exemplary PRL generation pro [0044] Carrier Mediumia memory medium as described cedure which includes deletion of duplicate system records in above, as well as a physical transmission medium, such as a the PRL. bus, network, and/ or other physical transmission medium that [0025] While embodiments described herein susceptible to conveys signals such as electrical, electromagnetic, or digital various modi?cations and alternative forms, speci?c embodi signals. ments thereof are shown by way of example in the drawings [0045] Programmable Hardware Elementiincludes vari and are herein described in detail. It should be understood, ous hardware devices comprising multiple programmable however, that the drawings and detailed description thereto function blocks connected via a programmable interconnect. are not intended to limit the embodiments to the particular Examples include FPGAs (Field Programmable Gate form disclosed, but on the contrary, the intention is to cover all Arrays), PLDs (Programmable Logic Devices), FPOAs modi?cations, equivalents and alternatives falling within the (Field Programmable Object Arrays), and CPLDs (Complex spirit and scope of the present embodiments as de?ned by the PLDs). The programmable function blocks may range from appended claims. ?ne grained (combinatorial logic or look up tables) to coarse US 2014/0011497 A1 Jan. 9, 2014

grained (arithmetic logic units or processor cores). A pro through 106-N. Each of the user devices may be referred to grammable hardware element may also be referred to as herein as a “user equipment” (UE). Thus, the user devices are “recon?gurable logic”. referred to as UEs or UE devices. [0046] Computer Systemiany of various types of comput [0051] The base station 102 may be a base transceiver sta ing or processing systems, including a personal computer tion (BTS) or cell site, and comprises hardWare that enables system (PC), mainframe computer system, Workstation, net Wireless communication With the user devices 106-1 through Work appliance, Internet appliance, personal digital assistant 106-N. The base station 102 may also be equipped to com (PDA), personal communication device, smart phone, televi municate With a netWork 100. Thus, the base station 102 may sion system, grid computing system, or other device or com facilitate communication betWeen the user devices and/or binations of devices. In general, the term “computer system” betWeen the user devices and the netWork 100. can be broadly de?ned to encompass any device (or combi [0052] The base station 102 and the user devices may be nation of devices) having at least one processor that executes con?gured to communicate over the transmission medium instructions from a memory medium. using any of various radio access technologies (RATs) or [0047] User Equipment (UE) (or “UE Device”)iany of telecommunication standards such as GSM, CDMA, WLL, various types of computer systems devices Which are mobile WAN, WiFi, WiMAX etc. or portable and Which performs Wireless communications. [0053] At least one UE 106, and possibly each UE 106, may Examples of UE devices include mobile telephones or smart be capable of communicating using multiple RATs. In other phones (e.g., iPhoneTM, AndroidTM-based phones), portable Words, one or more of the UEs 106 may be multimode gaming devices (e.g., Nintendo DSTM, PlayStation Por devices. For example, a UE 106 might be con?gured to com tableTM, Gameboy AdvanceTM, iPhoneTM), laptops, PDAs, municate using either of a 3GPP radio access technology portable lntemet devices, music players, data storage devices, (such as LTE) or a 3GPP2 radio access technology (such as or other handheld devices, etc. In general, the term “UE” or CDMA2000). Other combinations of radio access technolo “UE device” can be broadly de?ned to encompass any elec gies (including more than tWo RATs) are also possible. tronic, computing, and/or telecommunications device (or [0054] The UE device 106 may thus be a multi-mode Wire combination of devices) Which is easily transported by a user less device and hence may be con?gured to communicate and capable of Wireless communication. using multiple RATs. Depending on the location of the [0048] Automaticallyirefers to an action or operation per device, it may be preferable to join one type of netWork at one formed by a computer system (e. g., softWare executed by the time, and another type of netWork at another time. For computer system) or device (e.g., circuitry, programmable example, one geographic region might only support one type hardWare elements, ASlCs, etc.), Without user input directly of netWork, While a different geographic region might only specifying or performing the action or operation. Thus the support the other type of netWork. Additionally, in some term “automatically” is in contrast to an operation being geographic areas, both types of netWorks may be supported, manually performed or speci?ed by the user, Where the user in Which case one type of netWork may be preferred (e.g., provides input to directly perform the operation. An auto because it is a home netWork, because it offers more and/or matic procedure may be initiated by input provided by the better communication capabilities, etc). user, but the subsequent actions that are performed “automati [0055] For example, a UE 106 may be able to communicate cally” are not speci?ed by the user, i.e., are not performed With base station 102 using a ?rst RAT, e.g., While in the “manually”, Where the user speci?es each action to perform. geographical area served by base station 102. The UE 106 For example, a user ?lling out an electronic form by selecting may also be able to communicate With other base stations each ?eld and providing input specifying information (e.g., Which utiliZe the ?rst RAT, e.g., While in geographical loca by typing information, selecting check boxes, radio selec tions served by the other base stations Which utiliZe the ?rst tions, etc.) is ?lling out the form manually, even though the RAT. In addition, a UE 106 Which is con?gured to commu computer system must update the form in response to the user nicate using multiple RATs may also be able to communicate actions. The form may be automatically ?lled out by the With base stations Which utiliZe a second RAT, e.g., While in computer system Where the computer system (e.g., softWare geographical locations served by the base stations Which executing on the computer system) analyZes the ?elds of the utiliZe the second RAT. Note that in some cases, a base station form and ?lls in the form Without any user input specifying may be able to communicate With a UE using any of multiple the ansWers to the ?elds. As indicated above, the user may RATs. For example, base station 102 may be able to commu invoke the automatic ?lling of the form, but is not involved in nicate With a UE 106 using either a ?rst RAT or a second RAT the actual ?lling of the form (e.g., the user is not manually (or both, simultaneously, e.g., using different antennas). In specifying ansWers to ?elds but rather they are being auto other cases, a particular base station may only be con?gured matically completed). The present speci?cation provides to communicate With UE devices using one RAT. various examples of operations being automatically per FIG. 2iUE Communicating With Base Station formed in response to actions the user has taken. [0056] FIG. 2 illustrates user equipment (UE) 106 (e.g., one FIG. 14Communication System of the devices 106-1 through 106-N) in communication With the base station 102. The UE 106 may be a device With [0049] FIG. 1 illustrates an exemplary (and simpli?ed) Wireless netWork connectivity such as a mobile phone, a Wireless communication system. It is noted that the system of hand-held device, a computer or a tablet, or virtually any type FIG. 1 is merely one example of a possible system, and of Wireless device. As shoWn, the UE 106 includes a housing, embodiments of the invention may be implemented in any of an antenna attached to or coupled to the housing, and various various systems, as desired. components contained Within the housing as described beloW [0050] As shoWn, the exemplary Wireless communication With respect to FIG. 3. system includes a base station 102 Which communicates over [0057] The UE 106 may include a processor that is con?g a transmission medium With one or more user devices 106-1 ured to execute program instructions stored in memory. The US 2014/0011497 A1 Jan. 9, 2014

UE 106 may perform any of the methods embodiments system record is a data structure comprising information that described herein by executing such stored instructions. In corresponds to or speci?es a respective RAT. some embodiments, the UE 1 06 may include a programmable [0064] The processor 202 of the UE device 106 may be hardWare element such as an FPGA (?eld-programmable con?gured to implement part or all of the methods described gate array) that is con?gured to perform any of the method herein, e.g., by executing program instructions stored on a embodiments described herein, or any portion of any of the memory medium (e.g., a non-transitory computer-readable method embodiments described herein. memory medium). In other embodiments, processor 202 may [0058] In some embodiments, the UE 106 may be con?g be con?gured as programmable hardWare element, such as an ured to communicate using any of multiple radio access tech FPGA (Field Programmable Gate Array), or as an ASIC nologies (RATs). For example, the UE 106 may be con?gured (Application Speci?c Integrated Circuit). to communicate using either of CDMA 2000 or LTE. Other combinations of RATs are also possible. FIG. 4iRemoval of Redundant System Records Within the [0059] In some embodiments, the UE 106 may include a PRL plurality of receive antennas and a corresponding plurality of [0065] FIG. 4 is a ?owchart illustrating operation of one receive chains. The term “receive chain” may refer to a pro embodiment of the invention for modifying a Preferred cessing path for the received signal. For example, the UE 106 Roaming List to remove duplicate system records in the PRL. may include separate signal processing chips, each having a The method shoWn in FIG. 4 may be performed by one or respective receive chain, for each of multiple radio access more of the UEs 106. Alternatively, the method may be used technologies. Alternatively (or in addition), multiple radio in conjunction With any of the systems or devices shoWn in the access technologies may share one or more parts of a receive above Figures, among other devices. In various embodi chain in the UE 106 in some embodiments. ments, some of the method elements shoWn may be per FIG. 3iExemplary Block Diagram of a UE formed concurrently, in a different order than shoWn, or may be omitted. Note also that additional method elements may [0060] FIG. 3 illustrates an exemplary block diagram of a also be performed as desired. UE 106. As shoWn, the UE 106 may include a system on chip [0066] In 402 the UE 106 stores a Preferred Roaming List (SOC) 200, Which may include portions for various purposes. (PRL). The PRL comprises one or more (typically a plurality For example, as shoWn, the SOC 200 may include processor of) system records for each respective geographic location (s) 202 Which may execute program instructions for the UE (GEO), Where each system record corresponds to a Radio 106 and display circuitry 204 Which may perform graphics Access Technology (RAT). The PRL may be any of various processing and provide display signals to the display 240. The PRL versions, including any of PRL versions A through E, processor(s) 202 may also be coupled to memory manage inclusive. The PRL may be created by the UE 1 06, or received ment unit (MMU) 240, Which may be con?gured to receive by the UE 106 from a base station. In one embodiment, the addresses from the processor(s) 202 and translate those UE 106 may receive a ?rst PRL from a base station and use addresses to locations in memory (e.g., memory 206, read this ?rst PRL and other information to generate a second only memory (ROM) 250, NAND ?ash memory 210) and/or PRL. to other circuits or devices, such as the display circuitry 204, [0067] The Preferred Roaming List (PRL) is a data struc radio 230, connector UP 220, and/or display 240. In some ture (e.g., a database) residing in a Wireless device, such as a embodiments, the MMU 240 may be included as a portion of cell phone, that contains information used during the system the processor(s) 202. (RAT) selection and acquisition process. The PRL may indi [0061] In the embodiment shoWn, ROM 250 may include a cate Which bands, sub bands and service provider identi?ers bootloader 252, Which may be executed by the processor(s) Will be scanned and in What priority order. The PRL is used by 202 during boot up or initialiZation. As also shoWn, the SOC the UE 106 to alloW the UE 106 to “roam”, i.e., to obtain 200 may be coupled to various other circuits of the UE 106. service outside of the home area. The PRL on a UE 106 may For example, the UE 106 may include various types of be updated periodically. This is desirable if the subscriber memory (e.g., including NAND ?ash 210), a connector inter uses the UE 106 outside the home area frequently, particu face 220 (e.g., for coupling to the computer system), the larly if they do so in multiple different areas. This alloWs the display 240, and Wireless communication circuitry (e.g., for UE 106 to choose the best roaming carriers, particularly LTE, CDMA2000, Bluetooth, WiFi, etc.). “roaming partners” With Whom the home carrier has a cost [0062] The UE device 106 may include at least one saving roaming agreement, rather than using non-a?iliated antenna, and in some embodiments multiple antennas, for carriers. PRL ?les can also be used to identify home netWorks performing Wireless communication With base stations. For along With roaming partners, thus making the PRL an actual example, the UE device 106 may use antennas 235 and 237 to list that determines the total coverage of the subscriber, both perform the Wireless communication. The UE 106 may be home and roaming coverage. con?gured to communicate Wirelessly using multiple (e.g., at [0068] In 404 the UE 106 determines if a system record is least tWo) RATs. duplicated in the PRL Within the same geographic location [0063] As shoWn, the UE 106 may include a SIM (Sub (GEO). In step 404 the UE 106 determines that a system scriber Identity Module) 310, Which may also be referred to record is duplicated if tWo system records present in the PRL as a smart card. The SIM 310 may take the form of a remov are exact copies of each other. As one example, the PRL may able SIM card. As one example, the SIM 310 may be a contain a ?rst system record that corresponds to a ?rst RAT Universal Integrated Circuit Card (U ICC) 310. In some and also may contain a second system record that also corre embodiments, the SIM 310 may store a preferred roaming list sponds to the ?rst RAT, but the ?rst and second system (PRL). The PRL may include one or more system records for records have different system identi?cations. In this example, each of various geographic regions, Wherein each system the UE 106 Would NOT determine these system records to be record corresponds to or speci?es a respective RAT. Each duplicates, as they are not exact copies of each other. US 2014/0011497 A1 Jan. 9, 2014

[0069] If the UE 106 determines that a duplicate system may be made available to the UE device 106 in order to assist record exists in the PRL, in 406 the UE 106 deletes one of the the UE 106 to select a telecommunication standard. Accord duplicate PRLs. In one embodiment, the UE 106 deletes the ing to some embodiments, one or more such priority lists may less preferred duplicate system record. For example, the PRL be stored on a smart card, such as Universal Integrated Circuit typically has system records sorted from most preferred to Card (UICC) 310. In some embodiments, priority lists may be least preferred. If the UE 106 discovers that the PRL includes stored in a subscriber identity module (SIM) on the smart tWo identical system records, the UE 106 deletes the least card. The priority lists may be made available to the UE 106 preferred system record (the one loWer in the list) and the prior to initial operation of the UE 106 (e.g., during con?gu more preferred system record remains in the PRL. ration of the UE 106 by a service provider) in some embodi [0070] In one embodiment, the UE 106 deletes the dupli ments. Alternatively, or in addition, the priority lists may be cate system record from both the copy of the PRL in the made available (and/or updated) during operation of the UE random access memory (RAM) 206 Where the PRL is being device 106, e. g., by request of a user, or automatically. Auto used as Well as the ROM 250 (e.g., ?ash memory). This matic updating or initial doWnloading of the priority lists to ensures that the PRL is properly modi?ed. In an alternate the smart card of the UE device 106 may be initiated by either embodiment, the UE 106 only modi?es the copy of the PRL a base station (e.g., the network/service provider) or the UE in the random access memory (RAM) 206. device 106 itself, according to various embodiments. [0071] In a ?rst exemplary embodiment, steps 404 and 406 [0077] It may be common for one priority list (a “location of FIG. 4 are performed While the PRL is being generated by priority list” or “LPL”) to be used to group sets of netWorks the MMSS algorithm. This is illustrated in FIG. 5. Thus, in (Which may operate according to different telecommunica this embodiment, as the UE 106 is creating the PRL, the UE tion standards) Which may be present in the same geographic 106 checks to determine if a system record is listed tWice region. In the exemplary embodiment of FIG. 7, MMSS Within the same GEO of the PRL in 502. If the UE 106 Location Priority List (MLPL) 312 may function as an LPL in determines that the system is listed tWice Within the same some embodiments. GEO, then the UE 106 deletes the less preferred system [0078] The LPL may also assign a relative priority to each record from the PRL in 504. netWork and/or telecommunication standard per listing, in [0072] In a second exemplary embodiment, steps 404 and some embodiments. Alternatively, the LPL may refer to (or 406 of FIG. 4 are performed after the PRL has been created include pointers to) one or more additional lists Which assign and stored. In this embodiment, the UE 106 examines the relative priority to each of multiple netWorks (and/ or telecom PRL after it has been created and removes redundant system munication standards) according to different scenarios (e.g., records. For example, as shoWn in the FIG. 6, the UE 106 may home, roaming, scenarios speci?c to particular geographic perform steps 404 and 406 at every RAT selection instance areas, or other scenarios). Such a set of lists may be referred (steps 602 and 604 of FIG. 6. The UE 106 may instead (or to as a “system priority list” or “SPL”. In the exemplary also) perform steps 404 and 406 based on some other repeti embodiment of FIG. 7, MMSS System Priority List (MSPL) tive or periodic basis and remove duplicate system records 314 may function as an SPL in some embodiments. from the PRL. [0079] A further priority list that may be available in some [0073] Thus, as described herein, embodiments of the embodiments is a ?rst preferred roaming list (PRL). The ?rst invention operate to remove redundant system records Within PRL may include information relating to the availability of the preferred roaming list (PRL). This may operate to miti netWorks Which operate according to a ?rst telecommunica gate the problems created by duplicate listing of systems tion standard in various geographic locations. One example Within the same GEO. In particular, the removal of redundant of such a ?rst PRL is the IS-683D PRL Which may be used in system records Within the PRL may operate to reduce or UE devices con?gured to communicate using a 3GPP2 tele eliminate unneeded or undesired BSR algorithm execution, communication protocol in some embodiments. In the exem i.e., System Selection Loops. In addition, the removal of plary embodiment of FIG. 7, EPRL 316 (Which may also be redundant system records Within the PRL may operate to an IS-683D PRL) may function as a ?rst PRL. reduce temporal service outages caused by the fact that no [0080] In at least some embodiments of the invention, the service origination is alloWed While the UE 106 is attempting ?rst PRL includes information that is useable to identify to ?nd the most preferred system. geographic regions Which support multiple telecommunica tion standards and regions Which support only one telecom FIG. 7 munication standard (or a smaller subset). It is noted that in [0074] FIG. 7 illustrates an exemplary embodiment of the current systems telecommunication carriers may not provide invention Which uses a ?rst preferred roaming list (e.g., EPRL this type of information in the ?rst PRL. HoWever, in embodi 316) as Well as other information to generate a second pre ments of the invention, the carriers provide this information in ferred roaming list (e.g., eqPRL 322). According to embodi the ?rst PRL. As one example, the carriers may provide this ments of the invention, the method may operate to remove information as Mobile Country Codes (MCCs). redundant system records from the second preferred roaming [0081] The ?rst PRL may enable the UE device 106 to list as it is being created. identify and select access points (e. g., cells provided by base [0075] In order to account for the various roaming possi stations) provided by its service provider outside of its bilities available to multi-mode UE device 106, the UE device “home” region, e.g., While “roaming”. In some embodiments 106 may employ a Multi-Mode System Selection (MMSS) the ?rst PRL may also assist the UE 106 in identifying access capability in order to select a preferred telecommunication points provided by other service providers, Which may utiliZe standard to use in a given area. the same telecommunication standard as the home service [0076] The UE 106 may initially boot up (or alternatively, provider of the UE device, e.g., While roaming in a different may perform a SIM refresh), e. g., as shoWn in the exemplary geographic region than its home region. Note that the ?rst embodiment of FIG. 7 in step 302. One or more priority lists PRL may also assist in identifying netWorks/access points US 2014/0011497 A1 Jan. 9, 2014

Within the UE device’s home region (Which may typically be stores the second PRL, either in the SIM 310 or RAM 320. In provided by its service provider, but may also or alternatively this situation, since the UE 106 does not create the second be provided by other service providers), in some embodi PRL, the UE 106 operates to remove duplicate records from ments. Alternatively, another ?le or data structure, such as the PRL When it is received from the base station 102, or equivalent home public land mobile netWork identi?er (EH periodically When the eqPRL is examined as mentioned PLMN) 318 shoWn in FIG. 7, may be available to assist in above. identifying/ selecting home region netWorks/access points. [0088] Embodiments of the invention may thus operate to The ?rst PRL may also provide information used for identi mitigate the problems created by duplicate listing of system fying the availability of telecommunication standards as records Within the same GEO of the PRL. In particular, described herein. embodiments of the invention operate to remove redundant [0082] Together, the ?rst PRL and the LPL (and in some system records Within the PRL. This operates to reduce or cases the SPL) may be used by the UE device 106 to construct eliminate unneeded or undesired BSR algorithm execution, a second PRL Which includes information relating to the i.e., System Selection Loops, and also operates to reduce a availability of multiple telecommunication standards in vari temporal service outage. ous geographic locations. That is, since the ?rst PRL may [0089] Although the embodiments above have been include information identifying Which netWorks operating described in considerable detail, numerous variations and according to a ?rst telecommunication standard may be avail modi?cations Will become apparent to those skilled in the art able in each of multiple geographical regions, and the LPL once the above disclosure is fully appreciated. It is intended may include information identifying Which netWorks of dif that the folloWing claims be interpreted to embrace all such ferent telecommunication standards may co-exist in a geo variations and modi?cations. graphic region, the UE 106 may be able to combine the We claim: information to generate a second PRL Which includes infor mation relating to the availability of netWorks Which operate 1. A method for operating a mobile Wireless User Equip ment (UE), the method comprising: according to any of multiple telecommunication standards in various geographic locations. The SPL (or LPL) may also be storing a preferred roaming list in a memory of the UE, used to prioritize the netWorks listed in the second PRL for a Wherein the preferred roaming list comprises a plurality given geographic region, in some embodiments. The second of system records Which specify radio access technolo PRL may then be stored. gies that can be used by the UE; [0083] According to the exemplary embodiment of FIG. 7, examining the preferred roaming list to determine if any the process of generating the second PRL based on the ?rst duplicate system records exist in the preferred roaming PRL and the LPL (and possible the SPL) is shoWn as step 304 list; and is performed by the UE device 106. The second PRL may deleting at least one duplicate system record from the pre be exempli?ed by eqPRL 322 (Which may be an IS-683E ferred roaming list in response to determining that the at PRL, in some embodiments) shoWn in FIG. 7, Which may be least one duplicate system record exists in the preferred stored in device RAM 320. roaming list. [0084] According to embodiments of the invention, as 2. The method of claim 1, further comprising: described above in FIG. 5, When the second PRL is being creating, by the UE, the preferred roaming list; generated in FIG. 7 the UE 106 may in 502 determine if a Wherein said examining the preferred roaming list and said system record is duplicated in the second PRL Within the deleting at least one duplicate system record are per same GEO. If the UE 106 determines that a system record is formed during said creating the preferred roaming list. duplicated in the second PRL, then in 504 the UE 106 deletes 3. The method of claim 1, the one or more duplicates. In one embodiment, the UE 106 Wherein said examining the preferred roaming list is per deletes the less preferred system record. formed When the UE examines the preferred roaming [0085] Once the second PRL has been generated (and list for radio access technology selection. stored), it may be used by the UE to search for and select a 4. The method of claim 1, netWork in any given geographical region. This is shoWn in Wherein said deleting the at least one duplicate system the exemplary embodiment of FIG. 4 as step 306. record comprises deleting a less preferred duplicate sys [0086] Once a netWork has been selected, normal device tem record from the preferred roaming list. operation may commence. This is shoWn in the exemplary 5. The method of claim 1, embodiment of FIG. 4 as step 308. Wherein said examining determines that duplicate system [0087] In some embodiments, the UE device 106 operates records exist in the preferred roaming list if tWo system to examine the second PRL and remove duplicate records at certain times after the second PRL has been created. For records present in the preferred roaming list are exact copies of each other. example, as described above in FIG. 6, in a second exemplary embodiment, the UE 106 examines the PRL at every System 6. The method of claim 1, Selection instance (step 602) and removes one or more dupli Wherein the preferred roaming list comprises a ?rst system cate records from the eqPRL Within a GEO (step 604). This record that corresponds to a ?rst radio access technology method may be useful Where the second PRL is changed, e.g., and a second system record that also corresponds to the by a base station, after creation. In addition, in some embodi ?rst radio access technology, Wherein the ?rst and sec ments the base station 102 (e.g., a telecommunication carrier) ond system records have different system identi?ca may perform the operation of creating the second PRL (e.g., tions; eqPRL 322) as described herein. In these embodiments, the Wherein said examining determines that the ?rst system base station 102 creates and provides the second PRL in a record and the second system record are not duplicates Wireless manner to the UE device 106, Which receives and of each other. US 2014/0011497 A1 Jan. 9, 2014

7. The method of claim 1, Wherein the processor is con?gured to delete the at least wherein said deleting the at least one duplicate system one duplicate system record from only the second copy record comprises deleting both a copy of the at least one of the preferred roaming list. duplicate system record in a random access memory and 17. The UE device of claim 10, Wherein the preferred a copy of the at least one duplicate system record from a roaming list comprises a plurality of data structures for each non-volatile memory of the UE device. respective geographic location (GEO), Where each data struc 8. The method of claim 1, further comprising: ture corresponds to a Radio Access Technology (RAT). the UE device selecting a radio access technology based on 18. The UE device of claim 7, Wherein the plurality of data the preferred roaming list. structures comprise a plurality of system records. 9. The method of claim 1, 19. The UE device of claim 7, Wherein the preferred roaming list is an Equivalent Pre ferred Roaming List (eqPRL). Wherein the UE device is a mobile, Wireless telephone. 10. A user equipment (UE) device, the UE device compris 20. A non-transitory computer readable memory medium mg: in a User Equipment (UE), Wherein the UE is a mobile Wire an antenna for performing Wireless communications With a less device capable of roaming on various netWorks, Wherein base station; the memory medium comprises program instructions Which a memory con?gured to store a preferred roaming list, are executable to: Wherein the preferred roaming list comprises informa store a preferred roaming list in a memory of the UE, tion regarding an ordering of radio access technologies Wherein the preferred roaming list comprises a plurality to be examined for roaming in one or more geographic of system records Which specify radio access technolo locations; gies that can be used by the UE; a processor con?gured to examine the preferred roaming examine the preferred roaming list to determine if any list to determine if any duplicate information exists in duplicate system records exist in the preferred roaming the preferred roaming list, and delete at least one dupli list; cate piece of information from the preferred roaming delete at least one duplicate system record from the pre list. ferred roaming list in response to determining that the at 11. The UE device of claim 10, least one duplicate system record exists in the preferred Wherein the processor is further con?gured to create the roaming list. preferred roaming list; 21. The non-transitory computer readable memory Wherein the processor is con?gured to examine the pre medium of claim 20, Wherein the program instructions are ferred roaming list and delete at least one duplicate piece further executable to: of information during creation of the preferred roaming create the preferred roaming list; list. 12. The UE device of claim 10, Wherein the program instructions examine the preferred Wherein the processor is further con?gured to examine the roaming list and delete at least one duplicate system preferred roaming list for radio access technology selec record during creation of the preferred roaming list. tion; 22. The non-transitory computer readable memory Wherein the processor is con?gured to examine the pre medium of claim 20, ferred roaming list for duplicate information and delete Wherein the program instructions examine the preferred at least one duplicate piece of information When the UE roaming list When the program instructions examine the examines the preferred roaming list for radio access preferred roaming list for radio access technology selec technology selection. tion. 13. The UE device of claim 10, 23. The non-transitory computer readable memory Wherein said deleting the at least one duplicate piece of medium of claim 20, information comprises deleting a less preferred dupli Wherein, When deleting at least one duplicate system cate piece of information from the preferred roaming record, the program instructions delete a less preferred list. duplicate system record from the preferred roaming list. 14. The UE device of claim 10, 24. The non-transitory computer readable memory Wherein the UE device is con?gured to select a radio access medium of claim 20, technology based on the preferred roaming list. Wherein the program instructions determine that duplicate 15. The UE device of claim 10, system records exist in the preferred roaming list if tWo Wherein the UE device comprises a non-volatile memory system records present in the preferred roaming list are Which stores a ?rst copy of the preferred roaming list and exact copies of each other. a random access memory Which stores a second copy of the preferred roaming list; 25. A handheld Wireless telephone device, the telephone device comprising: Wherein the processor is con?gured to delete the at least one duplicate system record from both the ?rst copy of a housing; the preferred roaming list and the second copy of the an antenna attached to the housing for performing Wireless preferred roaming list. communications With a base station; 16. The UE device of claim 10, a memory contained Within the housing and con?gured to Wherein the UE device comprises a non-volatile memory store a preferred roaming list, Wherein the preferred Which stores a ?rst copy of the preferred roaming list and roaming list comprises information regarding an order a random access memory Which stores a second copy of ing of radio access technologies to be examined for the preferred roaming list; roaming in one or more geographic locations; US 2014/0011497 A1 Jan. 9, 2014

a processor contained Within the housing and con?gured to examine the preferred roaming list to determine if any duplicate information exists in the preferred roaming list, and delete at least one duplicate piece of information from the preferred roaming list.

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