68:
968:). An A3/A8 algorithm is implemented in Subscriber Identity Module (SIM) cards and in GSM network Authentication Centers. It is used to authenticate the customer and generate a key for encrypting voice and data traffic, as defined in 3GPP TS 43.020 (03.20 before Rel-4). Development of A3 and A8 algorithms is considered a matter for individual GSM network operators, although example implementations are available. To encrypt Global System for Mobile Communications (GSM) cellular communications A5 algorithm is used.
1006:, or collected from the MS. In practice, for performance reasons, most vendors integrate the VLR directly to the V-MSC and, where this is not done, the VLR is very tightly linked with the MSC via a proprietary interface. Whenever an MSC detects a new MS in its network, in addition to creating a new record in the VLR, it also updates the HLR of the mobile subscriber, apprising it of the new location of that MS. If VLR data is corrupted it can lead to serious issues with text messaging and call services.
2298:
384:(G-MSC) is the MSC that determines which "visited MSC" (V-MSC) the subscriber who is being called is currently located at. It also interfaces with the PSTN. All mobile to mobile calls and PSTN to mobile calls are routed through a G-MSC. The term is only valid in the context of one call, since any MSC may provide both the gateway function and the visited MSC function. However, some manufacturers design dedicated high capacity MSCs which do not have any
138:
27:
2287:
1112:
country, which obliges all cellular operators of the country to do so. Therefore, in the delivery of the basic components of the network switching subsystem (core network) is often already present EIR with basic functionality, which includes a ‘whitelisted’ response to all CheckIMEI and the ability to fill IMEI blacklist, which will be given a ‘blacklisted’ response.
1168:
allowed to register the device. To do this, there are blocked all services, except the following: calls to a specific service number, sending SMS to a specific service number, and all
Internet traffic is redirected to a specific landing page. This is achieved by the fact that EIR can send commands to several MNO systems (HLR,
1251:
According to U.S. law, which has also been copied into many other countries, especially in Europe, all telecommunications equipment must provide facilities for monitoring the calls of selected users. There must be some level of support for this built into any of the different elements. The concept of
1111:
Most often, EIR uses the IMEI blacklist feature, which contains the IMEI of the devices that need to be banned from the network. As a rule, these are stolen or lost devices. Mobile operators rarely use EIR capabilities to block devices on their own. Usually blocking begins when there is a law in the
1062:
To purge the subscriber record if a subscriber becomes inactive whilst in the area of a VLR. The VLR deletes the subscriber's data after a fixed time period of inactivity and informs the HLR (e.g., when the phone has been switched off and left off or when the subscriber has moved to an area with no
1107:
The switching equipment must use the EIR response to determine whether or not to allow the device to register or re-register on the network. Since the response of switching equipment to ‘greylisted’ and ‘unknown equipment’ responses is not clearly described in the standard, they are most often not
763:
If the authentication fails, then no services are possible from that particular combination of SIM card and mobile phone operator attempted. There is an additional form of identification check performed on the serial number of the mobile phone described in the EIR section below, but this is not
1167:
Other functions may be required in individual cases. For example, Kazakhstan has introduced mandatory registration of devices and their binding to subscribers. But when a subscriber appears in the network with a new device, the network operation is not blocked completely, and the subscriber is
364:
In the GSM mobile phone system, in contrast with earlier analogue services, fax and data information is sent digitally encoded directly to the MSC. Only at the MSC is this re-coded into an "analogue" signal (although actually this will almost certainly mean sound is encoded digitally as a
929:(which is burned onto the SIM) into the A3 algorithm as appropriate and an SRES is calculated and sent back to the MSC. If this SRES matches with the SRES in the triplet (which it should if it is a valid SIM), then the mobile is allowed to attach and proceed with GSM services.
1119:) system, which is integrated with the EIR of all operators and transmits to them the actual lists of identifiers that must be used when processing CheckIMEI requests. In doing so, there may be many new requirements for EIR systems that are not present in the legacy EIR:
709:
Manage the mobility of subscribers by means of updating their position in administrative areas called 'location areas', which are identified with a LAC. The action of a user of moving from one LA to another is followed by the HLR with a
Location area update
445:
within the area that it serves. The functionality enables split control between (signaling ) and user plane (bearer in network element called as media gateway/MG), which guarantees better placement of network elements within the network.
960:
The AuC is usually collocated with the HLR, although this is not necessary. Whilst the procedure is secure for most everyday use, it is by no means hack proof. Therefore, a new set of security methods was designed for 3G phones.
625:
used by mobile phones to make and receive calls. The primary MSISDN is the number used for making and receiving voice calls and SMS, but it is possible for a SIM to have other secondary MSISDNs associated with it for
440:
is a soft-switch variant (therefore it may be referred to as mobile soft switch, MSS) of the mobile switching center, which provides circuit-switched calling mobility management, and GSM services to the mobile phones
376:
There are various different names for MSCs in different contexts which reflects their complex role in the network, all of these terms though could refer to the same MSC, but doing different things at different times.
826:
The MSC which requests a new batch of triplet data for an IMSI after the previous data have been used. This ensures that same keys and challenge responses are not used twice for a particular mobile.
1199:
is responsible for processing the toll tickets generated by the VLRs and HLRs and generating a bill for each subscriber. It is also responsible for generating billing data of roaming subscriber.
1260:. Generally, lawful Interception implementation is similar to the implementation of conference call. While A and B are talking with each other, C can join the call and listen silently.
599:(HLR) is a central database that contains details of each mobile phone subscriber that is authorized to use the GSM core network. There can be several logical, and physical, HLRs per
1351:
1115:
When the legislative framework for blocking registration of devices in cellular networks appears in the country, the telecommunications regulator usually has a
Central EIR (
1893:
1257:
97:
1179:
The most common suppliers of individual EIR systems (not as part of a complex solution) are the companies BroadForward, Mahindra
Comviva, Mavenir, Nokia, Eastwind.
756:
core network (typically when the phone is powered on). Once the authentication is successful, the HLR is allowed to manage the SIM and services described above. An
2141:
2153:
1713:
155:
40:
1440:
2326:
1914:
760:
is also generated that is subsequently used to encrypt all wireless communications (voice, SMS, etc.) between the mobile phone and the GSM core network.
705:
The main function of the HLR is to manage the fact that SIMs and phones move around a lot. The following procedures are implemented to deal with this:
1344:
1134:
1013:
604:
1123:
Synchronizing lists with CEIR. CEIR systems are not described by a standard, so the protocols and exchange mode may differ from country to country.
1079:
2221:
804:
1670:
668:
transactions and messages from elements in the GSM network, for example, the location update messages received as mobile phones roam around.
2126:
1567:
202:
1758:
1337:
1116:
174:
2136:
1169:
298:(PSTN). The architecture contains specific features and functions which are needed because the phones are not fixed in one location.
1825:
1474:
1395:
295:
239:
221:
119:
54:
361:, handles mobility and hand-over requirements during the call and takes care of charging and real-time prepaid account monitoring.
181:
1837:
1420:
1370:
46:
2226:
1830:
1400:
464:(CS) used here originates from traditional telecommunications systems. However, modern MSS and MGW devices mostly use generic
2172:
431:
415:
188:
159:
852:
When the MSC asks the AuC for a new set of triplets for a particular IMSI, the AuC first generates a random number known as
918:) form the triplet sent back to the MSC. When a particular IMSI requests access to the GSM core network, the MSC sends the
2165:
2148:
322:
997:
may be served by many MSCs in case of MSC in pool), hence a subscriber cannot be present in more than one VLR at a time.
1665:
1611:
1586:
1469:
1460:
1209:
1173:
644:
567:
326:
170:
80:
1626:
90:
84:
76:
1087:
600:
497:
454:
607:(IMSI)/MSISDN pair can be associated with only one logical HLR (which can span several physical nodes) at a time.
148:
1621:
101:
2291:
2121:
1883:
1877:
1871:
1820:
1788:
1390:
994:
990:
943:(BSC) so that all communications can be encrypted and decrypted. Of course, the mobile phone can generate the
634:
to the HLR record. The HLR data is stored for as long as a subscriber remains with the mobile phone operator.
2241:
1849:
1490:
665:
580:
469:
2266:
1378:
1272:
940:
848:
Algorithm id. (the standard algorithms are called A3 or A8, but an operator may choose a proprietary one).
508:
453:(MGW) makes it possible to cross-connect circuit-switched calls switched by using IP, ATM AAL2 as well as
385:
354:
voice calls and SMS as well as other services (such as conference calls, FAX, and circuit-switched data).
317:
calls. It was extended with an overlay architecture to provide packet-switched data services known as the
283:
1415:
989:) that have roamed into the jurisdiction of the Mobile Switching Center (MSC) which it serves. Each main
767:
Proper implementation of security in and around the AuC is a key part of an operator's strategy to avoid
195:
2321:
2204:
2131:
1557:
1066:
To delete the subscriber record when a subscriber explicitly moves to another, as instructed by the HLR.
1028:
366:
314:
310:
287:
796:
is securely burned into the SIM during manufacture and is also securely replicated onto the AuC. This
2209:
2194:
2184:
1410:
1405:
1127:
726:
Responsible for all SRI related queries (i.e. for invoke SRI, HLR should give sack SRI or SRI reply).
774:
The AuC does not engage directly in the authentication process, but instead generates data known as
388:(BSS) connected to them. These MSCs will then be the gateway MSC for many of the calls they handle.
2261:
2199:
2189:
2179:
1246:
351:
272:
614:
issued by the mobile phone operator. Each SIM has a unique identifier called an IMSI which is the
268:
2302:
461:
318:
2091:
2065:
1053:
To track where the subscriber is within the VLR area (location area) when no call is ongoing.
2216:
2116:
2111:
1988:
1430:
1360:
622:
1282:
2160:
1323:
1302:
Shahabuddin, Shahria; Rahaman, Sadiqur; Rehman, Faisal; Ahmad, Ijaz; Khan, Zaheer (2018).
1050:
To inform the HLR that a subscriber has arrived in the particular area covered by the VLR.
964:
In practice, A3 and A8 algorithms are generally implemented together (known as A3/A8, see
657:
477:
473:
803:
is never transmitted between the AuC and SIM, but is combined with the IMSI to produce a
2251:
2246:
2075:
1381:
986:
757:
745:
723:
Remove subscriber data from the previous VLR when a subscriber has roamed away from it.
621:
Another important item of data associated with the SIM are the MSISDNs, which are the
537:(VLR) provides subscriber information when the subscriber is outside its home network.
2315:
2256:
779:
778:
for the MSC to use during the procedure. The security of the process depends upon a
450:
276:
716:
Broker between the G-MSC or SMSC and the subscriber's current VLR in order to allow
2231:
1978:
1962:
1595:
717:
557:
306:
302:
1187:
Connected more or less directly to the GSM core network are many other functions.
1126:
Supporting additional lists – IMEI white list, IMEI grey list, list of allocated
693:
system for delivering notifications to the mobile phone that a message is waiting
2060:
2009:
1919:
1907:
1133:
Support in lists not only IMEI but also bindings – IMEI-IMSI, IMEI-MSISDN, IMEI-
768:
615:
137:
713:
Send the subscriber data to a VLR or SGSN when a subscriber first roams there.
690:
631:
1329:
1232:
291:
1082:(checkIMEI) of mobile devices that come from the switching equipment (MSC,
882:
are fed into the A3 algorithm and the signed response (SRES) is calculated.
1100:
greylisted – the device is allowed to register on the network temporarily.
2039:
1943:
1842:
1765:
1732:
1692:
1686:
749:
683:
The VLR for handling requests from mobile phones to attach to the network
611:
465:
407:
350:(MSC) is the primary service delivery node for GSM/CDMA, responsible for
330:
696:
The AuC for authentication and ciphering and exchange of data (triplets)
2273:
1770:
1576:
1510:
1505:
1425:
1277:
1097:
blacklisted – the device is prohibited from registering on the network.
965:
950:
itself by feeding the same RAND supplied during authentication and the
922:
part of the triplet to the SIM. The SIM then feeds this number and the
541:
442:
279:
399:(VLR) associated with this MSC will have the subscriber's data in it.
1982:
1853:
1753:
1495:
1435:
1138:
501:
1160:
Accumulating the subscribers’ profiles (history of device changing).
1059:
To allocate roaming numbers during the processing of incoming calls.
637:
Examples of other data stored in the HLR against an IMSI record is:
1157:
Integration with the billing system to receive IMSI-MSISDN bundles.
2070:
2055:
2018:
2005:
1924:
1902:
1708:
1500:
1219:
1215:
932:
After successful authentication, the MSC sends the encryption key
647:(GPRS) settings to allow the subscriber to access packet services.
563:
Connecting outgoing calls to other mobile subscribers or the PSTN.
523:
2236:
1934:
1748:
1616:
1543:
1083:
651:
516:
419:
1333:
1094:
whitelisted – the device is allowed to register on the network.
321:. This allows mobile phones to have access to services such as
1656:
1631:
1552:
1539:
1515:
1151:
627:
395:(V-MSC) is the MSC where a customer is currently located. The
370:
264:
131:
61:
20:
16:
1000:
The data stored in the VLR has either been received from the
641:
GSM services that the subscriber has requested or been given.
290:
and allows mobile devices to communicate with each other and
2034:
1957:
1803:
1727:
1645:
1529:
1450:
1214:
supports the sending of multimedia messages (e.g., images,
1056:
To allow or disallow which services the subscriber may use.
527:
512:
1163:
Long-term storage of processing of all CheckIMEI requests.
1147:
Automatic adding the item to a list in separate scenarios.
664:
The HLR is a system which directly receives and processes
1078:
is a system that handles real-time requests to check the
807:
for identification purposes and an encryption key called
1324:
426:
Mobile switching center server (MSC-Server, MSCS or MSS)
414:
is the MSC toward which a handover should take place. A
896:
are fed into the A8 algorithm and a session key called
1025:
GSM services that the subscriber is allowed to access.
418:
is a part of the redesigned MSC concept starting from
1001:
301:
The NSS originally consisted of the circuit-switched
1222:
and their combinations) to (or from) MMS-bluetooth.
818:
Other GSM core network elements connected to the AuC
672:
Other GSM core network elements connected to the HLR
534:
484:
Other GSM core network elements connected to the MSC
396:
2104:
2084:
2048:
2033:
1998:
1971:
1956:
1933:
1892:
1863:
1813:
1802:
1781:
1741:
1726:
1701:
1679:
1655:
1644:
1604:
1585:
1566:
1538:
1528:
1483:
1459:
1449:
1377:
1256:is also known, following the relevant U.S. law, as
1154:
notifications to subscribers in separate scenarios.
526:(UTRAN) which handles the radio communication with
457:. More information is available in 3GPP TS 23.205.
162:. Unsourced material may be challenged and removed.
1144:Supporting the customized logic of lists applying.
1103:An error ‘unknown equipment’ may also be returned.
1320:4GLET - the standardisation body for GSM and UMTS
993:in the network is served by exactly one VLR (one
835:The AuC stores the following data for each IMSI:
560:as they arrive based on information from the VLR.
511:(BSS) which handles the radio communication with
493:
369:(PCM) signal in a 64-kbit/s timeslot, known as a
1090:). The answer contains the result of the check:
576:Carrying out handovers from this MSC to another.
89:but its sources remain unclear because it lacks
718:incoming calls or text messages to be delivered
660:settings applicable for each associated MSISDN.
472:. MSS software may run on generic computers or
1345:
8:
822:The AuC connects to the following elements:
676:The HLR connects to the following elements:
504:number (MSISDN; i.e., the telephone number).
488:The MSC connects to the following elements:
55:Learn how and when to remove these messages
2045:
1968:
1810:
1738:
1652:
1535:
1456:
1352:
1338:
1330:
1203:Multimedia messaging service center (MMSC)
470:next-generation telecommunication networks
240:Learn how and when to remove this message
222:Learn how and when to remove this message
120:Learn how and when to remove this message
1306:. John Wiley & Sons Ltd. p. 12.
814:for use in over the air communications.
650:Current location of subscriber (VLR and
605:international mobile subscriber identity
566:Delivering SMSs from subscribers to the
1294:
1022:MSISDN (the subscriber's phone number).
782:between the AuC and the SIM called the
2222:Multimedia Broadcast Multicast Service
1046:The primary functions of the VLR are:
630:and data calls. Each MSISDN is also a
583:such as conference calls or call hold.
680:The G-MSC for handling incoming calls
524:UMTS terrestrial radio access network
7:
2180:Spectral efficiency comparison table
1304:A Comprehensive Guide to 5G Security
1037:SCP Address(For Prepaid Subscriber).
573:Arranging handovers from BSC to BSC.
160:adding citations to reliable sources
1016:(the subscriber's identity number).
867:to produce two numbers as follows:
686:The SMSC for handling incoming SMSs
496:(HLR) for obtaining data about the
1034:The HLR address of the subscriber.
540:Other MSCs for procedures such as
14:
2327:Telecommunications infrastructure
1071:Equipment identity register (EIR)
357:The MSC sets up and releases the
296:public switched telephone network
36:This article has multiple issues.
2296:
2285:
1371:List of mobile phone generations
764:relevant to the AuC processing.
752:that attempts to connect to the
610:The HLRs store details of every
136:
66:
25:
983:Visitor Location Register (VLR)
972:Visitor location register (VLR)
586:Generating billing information.
558:Delivering calls to subscribers
147:needs additional citations for
44:or discuss these issues on the
1237:records and stores voicemail.
438:mobile switching center server
432:Mobile switching centre server
416:mobile switching center server
286:. It is owned and deployed by
1:
1326:- a PDF eBook by Gunnar Heine
1241:Lawful interception functions
591:Home location register (HLR)
337:Mobile switching center (MSC)
171:"Network switching subsystem"
2292:Telecommunication portal
1210:multimedia messaging service
1003:Home Location Register (HLR)
645:General Packet Radio Service
568:short message service center
731:Authentication center (AuC)
253:Network switching subsystem
2343:
1789:CDMA2000 1xEV-DO Release 0
1244:
1063:coverage for a long time).
985:is a database of the MSs (
860:is then combined with the
601:public land mobile network
553:Tasks of the MSC include:
429:
2282:
1671:EDGE/EGPRS - Evolved EDGE
1596:D-AMPS (IS-54 and IS-136)
1368:
652:serving GPRS support node
535:visitor location register
397:visitor location register
991:base transceiver station
410:has been initiated. The
406:is the MSC from which a
284:network of base stations
267:system that carries out
263:) is the component of a
75:This article includes a
2127:Comparison of standards
1766:UTRA-TDD LCR / TD-SCDMA
1183:Other support functions
1009:Data stored include:
957:into the A8 algorithm.
941:base station controller
744:(AuC) is a function to
509:base station subsystems
386:base station subsystems
348:mobile switching center
305:, used for traditional
104:more precise citations.
2132:Channel access methods
1771:UTRA-TDD HCR / TD-CDMA
1273:Base station subsystem
1226:Voicemail system (VMS)
1042:Procedures implemented
831:Procedures implemented
701:Procedures implemented
597:home location register
581:supplementary services
570:(SMSC) and vice versa.
549:Procedures implemented
494:home location register
468:technologies and form
288:mobile phone operators
2303:Telephones portal
1411:MTA - MTB - MTC - MTD
1269:The GSM core network.
742:authentication center
367:pulse-code modulation
359:end-to-end connection
315:circuit switched data
309:such as voice calls,
1920:iBurst (IEEE 802.20)
1693:CDMA2000 1X Advanced
1019:Authentication data.
618:to each HLR record.
502:mobile services ISDN
156:improve this article
1806:(3.5G, 3.75G, 3.9G)
1648:(2.5G, 2.75G, 2.9G)
1416:Mobile TeleSeratout
1254:lawful interception
1247:Lawful interception
1191:Billing center (BC)
1029:access point (GPRS)
603:(PLMN), though one
273:mobility management
2294:
1880:(TIA/EIA/IS-856-B)
1874:(TIA/EIA/IS-856-A)
1872:1xEV-DO Revision A
805:challenge/response
77:list of references
2309:
2308:
2112:Cellular networks
2100:
2099:
2029:
2028:
1952:
1951:
1798:
1797:
1754:UTRA-FDD / W-CDMA
1722:
1721:
1689:(TIA/EIA/IS-2000)
1640:
1639:
1524:
1523:
623:telephone numbers
462:Circuit switching
319:GPRS core network
250:
249:
242:
232:
231:
224:
206:
130:
129:
122:
59:
2334:
2301:
2300:
2299:
2290:
2289:
2288:
2217:Mobile broadband
2117:Mobile telephony
2105:Related articles
2046:
1989:LTE Advanced Pro
1969:
1884:EV-DO Revision C
1878:EV-DO Revision B
1811:
1739:
1653:
1536:
1457:
1382:radio telephones
1361:Cellular network
1354:
1347:
1340:
1331:
1308:
1307:
1299:
474:virtual machines
261:GSM core network
245:
238:
227:
220:
216:
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207:
205:
164:
140:
132:
125:
118:
114:
111:
105:
100:this article by
91:inline citations
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2185:Frequency bands
2096:
2080:
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2025:
1994:
1961:
1948:
1929:
1888:
1859:
1805:
1804:3G transitional
1794:
1777:
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1718:
1697:
1675:
1647:
1646:2G transitional
1636:
1600:
1581:
1577:cdmaOne (IS-95)
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1445:
1373:
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1358:
1317:
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1311:
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1300:
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1249:
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1228:
1205:
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1185:
1073:
1044:
987:Mobile stations
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901:
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81:related reading
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2081:
2079:
2078:
2073:
2068:
2063:
2058:
2052:
2050:
2043:
2031:
2030:
2027:
2026:
2024:
2023:
2022:
2021:
2016:
2002:
2000:
1996:
1995:
1993:
1992:
1986:
1975:
1973:
1966:
1954:
1953:
1950:
1949:
1947:
1946:
1940:
1938:
1931:
1930:
1928:
1927:
1922:
1917:
1912:
1911:
1910:
1899:
1897:
1890:
1889:
1887:
1886:
1881:
1875:
1867:
1865:
1861:
1860:
1858:
1857:
1847:
1846:
1845:
1835:
1834:
1833:
1828:
1817:
1815:
1808:
1800:
1799:
1796:
1795:
1793:
1792:
1785:
1783:
1779:
1778:
1776:
1775:
1774:
1773:
1768:
1763:
1762:
1761:
1745:
1743:
1736:
1724:
1723:
1720:
1719:
1717:
1716:
1711:
1705:
1703:
1699:
1698:
1696:
1695:
1690:
1683:
1681:
1677:
1676:
1674:
1673:
1668:
1662:
1660:
1650:
1642:
1641:
1638:
1637:
1635:
1634:
1629:
1624:
1619:
1614:
1608:
1606:
1602:
1601:
1599:
1598:
1592:
1590:
1583:
1582:
1580:
1579:
1573:
1571:
1564:
1563:
1561:
1560:
1555:
1549:
1547:
1533:
1526:
1525:
1522:
1521:
1519:
1518:
1513:
1508:
1503:
1498:
1493:
1487:
1485:
1481:
1480:
1478:
1477:
1472:
1466:
1464:
1454:
1447:
1446:
1444:
1443:
1438:
1433:
1428:
1426:Autotel (PALM)
1423:
1418:
1413:
1408:
1403:
1398:
1393:
1387:
1385:
1375:
1374:
1369:
1366:
1365:
1359:
1357:
1356:
1349:
1342:
1334:
1328:
1327:
1321:
1316:
1315:External links
1313:
1310:
1309:
1293:
1292:
1290:
1287:
1286:
1285:
1280:
1275:
1270:
1265:
1262:
1245:Main article:
1242:
1239:
1227:
1224:
1204:
1201:
1197:billing center
1192:
1189:
1184:
1181:
1165:
1164:
1161:
1158:
1155:
1148:
1145:
1142:
1131:
1124:
1105:
1104:
1101:
1098:
1095:
1072:
1069:
1068:
1067:
1064:
1060:
1057:
1054:
1051:
1043:
1040:
1039:
1038:
1035:
1032:
1026:
1023:
1020:
1017:
978:
975:
973:
970:
953:
946:
935:
925:
914:
905:
904:
903:is calculated.
899:
888:
883:
874:
863:
850:
849:
846:
842:
832:
829:
828:
827:
819:
816:
810:
799:
792:
785:
758:encryption key
737:
734:
732:
729:
728:
727:
724:
721:
714:
711:
702:
699:
698:
697:
694:
687:
684:
681:
673:
670:
662:
661:
655:
648:
642:
592:
589:
588:
587:
584:
577:
574:
571:
564:
561:
550:
547:
546:
545:
538:
531:
530:mobile phones.
520:
519:mobile phones.
505:
485:
482:
430:Main article:
427:
424:
420:3GPP Release 4
343:
340:
338:
335:
275:functions for
248:
247:
230:
229:
144:
142:
135:
128:
127:
85:external links
74:
72:
65:
60:
34:
33:
31:
24:
15:
13:
10:
9:
6:
4:
3:
2:
2339:
2328:
2325:
2323:
2320:
2319:
2317:
2304:
2293:
2281:
2275:
2272:
2268:
2267:Wi-Fi Calling
2265:
2263:
2260:
2258:
2255:
2253:
2250:
2248:
2245:
2244:
2243:
2240:
2238:
2235:
2233:
2230:
2228:
2227:NGMN Alliance
2225:
2223:
2220:
2218:
2215:
2211:
2208:
2206:
2203:
2201:
2198:
2196:
2193:
2191:
2188:
2187:
2186:
2183:
2181:
2178:
2174:
2171:
2167:
2164:
2163:
2162:
2159:
2155:
2152:
2151:
2150:
2147:
2143:
2140:
2139:
2138:
2135:
2134:
2133:
2130:
2128:
2125:
2123:
2120:
2118:
2115:
2113:
2110:
2109:
2107:
2103:
2093:
2090:
2089:
2087:
2083:
2077:
2074:
2072:
2069:
2067:
2064:
2062:
2059:
2057:
2054:
2053:
2051:
2047:
2044:
2041:
2036:
2032:
2020:
2017:
2014:
2013:
2011:
2007:
2004:
2003:
2001:
1997:
1990:
1987:
1984:
1980:
1977:
1976:
1974:
1970:
1967:
1964:
1959:
1955:
1945:
1942:
1941:
1939:
1936:
1932:
1926:
1923:
1921:
1918:
1916:
1913:
1909:
1906:
1905:
1904:
1901:
1900:
1898:
1895:
1891:
1885:
1882:
1879:
1876:
1873:
1869:
1868:
1866:
1862:
1855:
1851:
1848:
1844:
1841:
1840:
1839:
1836:
1832:
1829:
1827:
1824:
1823:
1822:
1819:
1818:
1816:
1812:
1809:
1807:
1801:
1790:
1787:
1786:
1784:
1780:
1772:
1769:
1767:
1764:
1760:
1757:
1756:
1755:
1752:
1751:
1750:
1747:
1746:
1744:
1740:
1737:
1734:
1729:
1725:
1715:
1712:
1710:
1707:
1706:
1704:
1700:
1694:
1691:
1688:
1685:
1684:
1682:
1678:
1672:
1669:
1667:
1664:
1663:
1661:
1658:
1654:
1651:
1649:
1643:
1633:
1630:
1628:
1625:
1623:
1620:
1618:
1615:
1613:
1610:
1609:
1607:
1603:
1597:
1594:
1593:
1591:
1588:
1584:
1578:
1575:
1574:
1572:
1569:
1565:
1559:
1556:
1554:
1551:
1550:
1548:
1545:
1541:
1537:
1534:
1531:
1527:
1517:
1514:
1512:
1509:
1507:
1504:
1502:
1499:
1497:
1494:
1492:
1489:
1488:
1486:
1482:
1476:
1473:
1471:
1470:AMPS - N-AMPS
1468:
1467:
1465:
1462:
1458:
1455:
1452:
1448:
1442:
1439:
1437:
1434:
1432:
1429:
1427:
1424:
1422:
1419:
1417:
1414:
1412:
1409:
1407:
1404:
1402:
1399:
1397:
1394:
1392:
1389:
1388:
1386:
1383:
1380:
1376:
1372:
1367:
1362:
1355:
1350:
1348:
1343:
1341:
1336:
1335:
1332:
1325:
1322:
1319:
1318:
1314:
1305:
1298:
1295:
1288:
1284:
1281:
1279:
1276:
1274:
1271:
1268:
1267:
1263:
1261:
1259:
1255:
1248:
1240:
1238:
1236:
1234:
1225:
1223:
1221:
1217:
1213:
1211:
1202:
1200:
1198:
1190:
1188:
1182:
1180:
1177:
1175:
1171:
1162:
1159:
1156:
1153:
1149:
1146:
1143:
1140:
1136:
1132:
1129:
1125:
1122:
1121:
1120:
1118:
1113:
1109:
1102:
1099:
1096:
1093:
1092:
1091:
1089:
1085:
1081:
1077:
1070:
1065:
1061:
1058:
1055:
1052:
1049:
1048:
1047:
1041:
1036:
1033:
1030:
1027:
1024:
1021:
1018:
1015:
1012:
1011:
1010:
1007:
1005:
1004:
998:
996:
992:
988:
984:
976:
971:
969:
967:
962:
958:
956:
949:
942:
938:
930:
928:
921:
917:
910:
907:The numbers (
902:
895:
891:
884:
881:
877:
870:
869:
868:
866:
859:
855:
847:
845:
838:
837:
836:
830:
825:
824:
823:
817:
815:
813:
806:
802:
795:
788:
781:
780:shared secret
777:
772:
770:
765:
761:
759:
755:
751:
747:
743:
735:
730:
725:
722:
719:
715:
712:
708:
707:
706:
700:
695:
692:
688:
685:
682:
679:
678:
677:
671:
669:
667:
659:
656:
653:
649:
646:
643:
640:
639:
638:
635:
633:
629:
624:
619:
617:
613:
608:
606:
602:
598:
590:
585:
582:
578:
575:
572:
569:
565:
562:
559:
556:
555:
554:
548:
543:
539:
536:
532:
529:
525:
521:
518:
514:
510:
506:
503:
499:
495:
491:
490:
489:
483:
481:
480:environment.
479:
475:
471:
467:
463:
458:
456:
452:
451:media gateway
447:
444:
439:
433:
425:
423:
421:
417:
413:
409:
405:
400:
398:
394:
389:
387:
383:
378:
374:
373:in America).
372:
368:
362:
360:
355:
353:
349:
341:
336:
334:
332:
328:
324:
320:
316:
312:
308:
304:
299:
297:
294:in the wider
293:
289:
285:
281:
278:
277:mobile phones
274:
270:
266:
262:
258:
254:
244:
241:
226:
223:
215:
204:
201:
197:
194:
190:
187:
183:
180:
176:
173: –
172:
168:
167:Find sources:
161:
157:
151:
150:
145:This article
143:
139:
134:
133:
124:
121:
113:
103:
99:
93:
92:
86:
82:
78:
73:
64:
63:
58:
56:
49:
48:
43:
42:
37:
32:
23:
22:
19:
2322:GSM standard
2232:Push-to-talk
2010:IEEE 802.16m
1979:LTE Advanced
1963:IMT Advanced
1908:IEEE 802.16e
1903:Mobile WiMAX
1864:3GPP2 family
1791:(TIA/IS-856)
1782:3GPP2 family
1680:3GPP2 family
1659:/3GPP family
1475:TACS - ETACS
1303:
1297:
1253:
1250:
1231:
1229:
1208:
1206:
1196:
1194:
1186:
1178:
1166:
1114:
1110:
1106:
1075:
1074:
1045:
1008:
1002:
999:
982:
980:
963:
959:
951:
944:
933:
931:
923:
919:
912:
908:
906:
897:
893:
886:
879:
872:
861:
857:
853:
851:
840:
834:
821:
808:
797:
790:
783:
775:
773:
766:
762:
753:
746:authenticate
741:
739:
704:
675:
663:
636:
620:
609:
596:
594:
552:
487:
459:
448:
437:
435:
411:
403:
401:
392:
390:
381:
379:
375:
363:
358:
356:
347:
345:
307:GSM services
303:core network
300:
260:
256:
252:
251:
236:
218:
209:
199:
192:
185:
178:
166:
154:Please help
149:verification
146:
116:
107:
96:Please help
88:
52:
45:
39:
38:Please help
35:
18:
2061:5G-Advanced
2049:3GPP family
1999:IEEE family
1991:(4.5G/4.9G)
1972:3GPP family
1814:3GPP family
1742:3GPP family
1687:CDMA2000 1X
1558:CSD - HSCSD
1031:subscribed.
977:Description
769:SIM cloning
736:Description
658:Call divert
616:primary key
579:Supporting
393:visited MSC
382:gateway MSC
342:Description
102:introducing
2316:Categories
1915:Flash-OFDM
1289:References
710:procedure.
691:voice mail
632:unique key
412:target MSC
404:anchor MSC
292:telephones
212:March 2009
182:newspapers
110:March 2019
41:improve it
2015:WiMax 2.1
1870:CDMA2000
1363:standards
1233:voicemail
1176:, etc.).
542:hand over
460:The term
47:talk page
2040:IMT-2020
1944:HiperMAN
1843:DC-HSDPA
1733:IMT-2000
1264:See also
1150:Sending
911:, SRES,
776:triplets
750:SIM card
612:SIM card
466:Internet
449:MSS and
408:handover
331:Internet
329:and the
269:call out
2274:Osmocom
2122:History
2092:DECT-5G
2066:NR-IIoT
1511:DataTAC
1506:Mobitex
1278:COMP128
966:COMP128
939:to the
856:. This
654:/SGSN).
443:roaming
352:routing
282:on the
280:roaming
196:scholar
98:improve
2076:NB-IoT
2042:(2021)
2037:(2018)
1983:E-UTRA
1965:(2013)
1960:(2009)
1937:family
1896:family
1854:E-UTRA
1735:(2001)
1730:(1998)
1589:family
1570:family
1546:family
1532:(1991)
1463:family
1453:(1979)
1436:B-Netz
1384:(1946)
1235:system
1212:center
1139:MSISDN
1130:, etc.
1108:used.
789:. The
313:, and
259:) (or
198:
191:
184:
177:
169:
2252:ViLTE
2247:VoLTE
2205:5G NR
2154:STDMA
2142:OFDMA
2085:Other
2071:LTE-M
2056:5G NR
2019:WiBro
2006:WiMAX
1925:WiBro
1838:HSPA+
1831:HSUPA
1826:HSDPA
1709:WiDEN
1702:Other
1605:Other
1568:3GPP2
1501:Hicap
1496:C-450
1484:Other
1401:Altai
1283:4GLET
1258:CALEA
1220:video
1216:audio
748:each
478:cloud
203:JSTOR
189:books
83:, or
2262:ViNR
2257:VoNR
2237:MIMO
2210:CDMA
2195:UMTS
2173:SDMA
2166:CDMA
2161:SSMA
2149:TDMA
2137:FDMA
1935:ETSI
1894:IEEE
1821:HSPA
1759:FOMA
1749:UMTS
1714:DECT
1666:GPRS
1617:iDEN
1612:CDPD
1587:AMPS
1544:3GPP
1461:AMPS
1421:AMTS
1396:IMTS
1230:The
1207:The
1195:The
1174:SMSC
1170:PCRF
1135:IMSI
1128:TACs
1117:CEIR
1084:SGSN
1080:IMEI
1014:IMSI
981:The
920:RAND
909:RAND
894:RAND
892:and
885:The
880:RAND
878:and
871:The
858:RAND
854:RAND
839:the
740:The
689:The
595:The
533:The
522:The
517:2.5G
515:and
507:The
500:and
492:The
436:The
402:The
391:The
380:The
346:The
271:and
175:news
2242:IMS
2200:LTE
2190:GSM
1850:LTE
1657:GSM
1632:CT2
1627:PHS
1622:PDC
1553:GSM
1540:GSM
1516:CT1
1491:NMT
1441:AMR
1431:ARP
1406:OLT
1391:MTS
1152:SMS
1088:MME
1076:EIR
995:BTS
754:gsm
666:MAP
628:fax
498:SIM
476:in
455:TDM
371:DS0
327:MMS
323:WAP
311:SMS
265:GSM
257:NSS
158:by
2318::
2035:5G
2012:)
1958:4G
1728:3G
1530:2G
1451:1G
1379:0G
1218:,
1172:,
1086:,
771:.
528:3G
513:2G
422:.
333:.
325:,
87:,
79:,
50:.
2008:(
1985:)
1981:(
1856:)
1852:(
1542:/
1353:e
1346:t
1339:v
1141:.
1137:-
954:i
952:K
947:c
945:K
936:c
934:K
926:i
924:K
915:c
913:K
900:c
898:K
889:i
887:K
875:i
873:K
864:i
862:K
843:i
841:K
811:c
809:K
800:i
798:K
793:i
791:K
786:i
784:K
720:.
544:.
255:(
243:)
237:(
225:)
219:(
214:)
210:(
200:·
193:·
186:·
179:·
152:.
123:)
117:(
112:)
108:(
94:.
57:)
53:(
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
