IP Multimedia Subsystem

1338:) over the P1 reference point. POTS phone connect to A-MGW over the z interface. The signalling is converted to H.248 in the A-MGW and passed to AGCF. AGCF interprets the H.248 signal and other inputs from the A-MGW to format H.248 messages into appropriate SIP messages. AGCF presents itself as P-CSCF to the S-CSCF and passes generated SIP messages to S-CSCF or to IP border via IBCF (Interconnection Border Control Function). Service presented to S-CSCF in SIP messages trigger PES AS. AGCF has also certain service independent logic, for example on receipt of off-hook event from A-MGW, the AGCF requests the A-MGW to play dial tone. 1220:(CoIx): The physical and logical linking of carriers and service providers based on simple IP connectivity irrespective of the levels of interoperability. For example, an IP interconnection of this type is not aware of the specific end to end service and, as a consequence, service specific network performance, QoS and security requirements are not necessarily assured. This definition does not exclude that some services may provide a defined level of interoperability. However, only SoIx fully satisfies NGN interoperability requirements. 1214:(SoIx): The physical and logical linking of NGN domains that allows carriers and service providers to offer services over NGN (i.e., IMS and PES) platforms with control, signalling (i.e., session based), which provides defined levels of interoperability. For instance, this is the case of "carrier grade" voice and/or multimedia services over IP interconnection. "Defined levels of interoperability" are dependent upon the service or the QoS or the Security, etc. 1949:-based format used for describing control logic. iFCs represent a provisioned subscription of a user to an application. They are stored in the HSS as part of the IMS Subscription Profile and are downloaded to the S-CSCF upon user registration (for registered users) or on processing demand (for services, acting as unregistered users). iFCs are valid throughout the registration lifetime or until the User Profile is changed. 1995:. For this situation, to provide some protection against the most significant threats, 3GPP defines some security mechanisms, which are informally known as "early IMS security," in TR33.978. This mechanism relies on the authentication performed during the network attachment procedures, which binds between the user's profile and its IP address. This mechanism is also weak because the signaling is not protected on the 888:(S-CSCF) is the central node of the signaling plane. It is a SIP server, but performs session control too. It is always located in the home network. It uses Diameter Cx and Dx interfaces to the HSS to download user profiles and upload user-to-S-CSCF associations (the user profile is only cached locally for processing reasons and is not changed). All necessary subscriber profile information is loaded from the HSS. 36: 132: 77: 410:

legacy networks to the new generation of networks based on IP networks. AGCF acts a SIP User agent towards the IMS and performs the role of P-CSCF. SIP User Agent functionality is included in the AGCF, and not on the customer device but in the network itself. Also added voice call continuity between circuit switching and packet switching domain (

488: 671:(IMPI) is a unique permanently allocated global identity assigned by the home network operator. It has the form of a Network Access Identifier(NAI) i.e. user.name@domain, and is used, for example, for Registration, Authorization, Administration, and Accounting purposes. Every IMS user shall have one IMPI. 409:

emulation service) are introduced to the wire-line network for the sake of inheritance of services which can be provided in PSTN network. AGCF works as a bridge interconnecting the IMS networks and the Megaco/H.248 networks. Megaco/H.248 networks offers the possibility to connect terminals of the old

2013:

also did a similar effort given their fixed networks scopes, although the procedures are different. To compensate for the lack of IPsec capabilities, TLS has been added as an option for securing the Gm interface. Later 3GPP Releases have included the Digest-MD5 method, towards a Common-IMS platform,

1858:

Used to exchange User Profile information (e.g., user-related data, group lists, user-service-related information or user location information or charging function addresses (used when the AS has not received the third-party REGISTER for a user)) between an AS (SIP AS or OSA SCS) and HSS. Also allow

1932:

The S-CSCF might apply filter criteria to determine the need to forward SIP requests to AS. It is important to note that services for the originating party will be applied in the originating network, while the services for the terminating party will be applied in the terminating network, all in the

993:

The AS-ILCM (Application Server - Incoming Leg Control Model) and AS-OLCM (Application Server - Outgoing Leg Control Model) store transaction state, and may optionally store session state depending on the specific service being executed. The AS-ILCM interfaces to the S-CSCF (ILCM) for an incoming

498:

The IP multimedia core network subsystem is a collection of different functions, linked by standardized interfaces, which grouped form one IMS administrative network. A function is not a node (hardware box): An implementer is free to combine two functions in one node, or to split a single function

1314:(ECUR) is used, the ECF (event charging function) first reserves a number of credit units in the user's account and then authorizes the MRFC or the AS. After the service is over, the number of spent credit units is reported and deducted from the account; the reserved credit units are then cleared. 1363: 1224:

An NGN interconnection mode can be direct or indirect. Direct interconnection refers to the interconnection between two network domains without any intermediate network domain. Indirect interconnection at one layer refers to the interconnection between two network domains with one or more

643:

Various identities may be associated with IMS: IP multimedia private identity (IMPI), IP multimedia public identity (IMPU), globally routable user agent URI (GRUU), wildcarded public user identity. Both IMPI and IMPU are not phone numbers or other series of digits, but

1719:

Application server sends SIP message to MRFC to play tone and announcement. This SIP message contains sufficient information to play tone and announcement or provide information to MRFC, so that it can ask more information from application server through Cr Interface.

2014:

yet in its own and again different approach. Although all 3 variants of Digest-MD5 authentication have the same functionality and are the same from the IMS terminal's perspective, the implementations on the Cx interface between the S-CSCF and the HSS are different.

759:

which not only protects the network, but also the IMS terminal. The use of an additional SBC between the IMS terminal and the P-CSCF is unnecessary and infeasible due to the signaling being encrypted on this leg. The terminal discovers its P-CSCF with either

1002:

Public Service Identities (PSI) are identities that identify services, which are hosted by application servers. As user identities, PSI takes the form of either a SIP or Tel URI. PSIs are stored in the HSS either as a distinct PSI or as a wildcarded PSI:

1970:

Shared - When provisioning, only a reference number (the shared iFC number) is assigned to the subscriber. During registration, only the number is sent to the CSCF, not the entire XML description. The complete XML will have previously been stored on the

1325:

IMS-based PES (PSTN Emulation System) provides IP networks services to analog devices. IMS-based PES allows non-IMS devices to appear to IMS as normal SIP users. Analog terminal using standard analog interfaces can connect to IMS-based PES in two ways:

1349:

over Gm reference point. The conversion from POTS service over the z interface to SIP occurs in the customer premises VoIP gateway. POTS signaling is converted to SIP and passed on to P-CSCF. VGW acts as SIP user agent and appears to P-CSCF as SIP

299:. From a logical architecture perspective, services need not have their own control functions, as the control layer is a common horizontal layer. However, in implementation this does not necessarily map into greater reduced cost and complexity. 686:). Also known as Address of Record (AOR). There can be multiple IMPU per IMPI. The IMPU can also be shared with another phone, so that both can be reached with the same identity (for example, a single phone-number for an entire family). 1928:

One of the most important features of IMS, that of allowing for a SIP application to be dynamically and differentially (based on the user's profile) triggered, is implemented as a filter-and-redirect signalling mechanism in the S-CSCF.

1307:(IEC) is used, a number of credit units is immediately deducted from the user's account by the ECF and the MRFC or AS is then authorized to provide the service. The service is not authorized when not enough credit units are available. 750:

that is the first point of contact for the IMS terminal. It can be located either in the visited network (in full IMS networks) or in the home network (when the visited network is not IMS compliant yet). Some networks may use a

1073:(BGCF) is a SIP proxy which processes requests for routing from an S-CSCF when the S-CSCF has determined that the session cannot be routed using DNS or ENUM/DNS. It includes routing functionality based on telephone numbers. 1053:(MRB) is a functional entity that is responsible for both collection of appropriate published MRF information and supplying of appropriate MRF information to consuming entities such as the AS. MRB can be used in two modes: 922:

reasons. It's the HSS that assigns the S-CSCF to a user, when it's queried by the I-CSCF. There are multiple options for this purpose, including a mandatory/optional capabilities to be matched between subscribers and

466:

Some operators opposed IMS because it was seen as complex and expensive. In response, a cut-down version of IMS—enough of IMS to support voice and SMS over the LTE network—was defined and standardized in 2010 as

291:(SIP). According to the 3GPP, IMS is not intended to standardize applications, but rather to aid the access of multimedia and voice applications from wireless and wireline terminals, i.e., to create a form of 2009:, which adopted also the IMS architecture but has no USIM/ISIM capabilities in their terminals, published deltas to the 3GPP specifications where the Digest-MD5 is a valid authentication option. Later on, 1285:(IOI) is a globally unique identifier shared between sending and receiving networks. Each domain has its own charging network. Billing systems in different domains will also exchange information, so that 1748:

Used for the interworking with another IMS network, when the BGCF has determined that a breakout should occur in the other IMS network to send SIP message from BGCF to the IBCF in the other network

1296:(IMS-GWF) which looks like a regular SIP application server. The IMS-GWF can signal the S-CSCF to terminate the session when the user runs out of credits during a session. The AS and MRFC use the 1654:

Used for the interworking with the PSTN/CS domain, when the BGCF has determined that a breakout should occur in another IMS network to send SIP message from BGCF to the BGCF in the other network

960:

mode. An AS can be located in the home network or in an external third-party network. If located in the home network, it can query the HSS with the Diameter Sh or Si interfaces (for a SIP-AS).

390:, inter-operability between IMS using different IP-connectivity networks, routing group identities, multiple registration and forking, presence, speech recognition and speech-enabled services ( 313:

Since it is becoming increasingly easier to access content and contacts using mechanisms outside the control of traditional wireless/fixed operators, the interest of IMS is being challenged.

975: 1330:

Via A-MGW (Access Media Gateway) that is linked and controlled by AGCF. AGCF is placed within the Operators network and controls multiple A-MGW. A-MGW and AGCF communicate using

1354:

Both A-MGW and VGW are unaware of the services. They only relay call control signalling to and from the PSTN terminal. Session control and handling is done by IMS components.

340:(RCS), which is also known as joyn or Advanced Messaging, and now RCS is operator's implementation. RCS also further added Presence/EAB (enhanced address book) functionality. 349:

IMS was defined by an industry forum called 3G.IP, formed in 1999. 3G.IP developed the initial IMS architecture, which was brought to the 3rd Generation Partnership Project (

1640:

Used for the interworking with the PSTN/CS domain, when the BGCF has determined that a breakout should occur in the same IMS network to send SIP message from BGCF to MGCF

1974:

Non-shared - when provisioning, the entire XML description of the iFC is assigned to the subscriber. During registration, the entire XML description is sent to the CSCF.

2134: 95: 262: 2078: 994:

leg and the AS-OLCM interfaces to the S-CSCF (OLCM) for an outgoing leg. Application Logic provides the service(s) and interacts between the AS-ILCM and AS-OLCM.

1229:. The intermediate network domain(s) provide(s) transit functionality to the two other network domains. Different interconnection modes may be used for carrying 1427:

Used by AS to find the HSS holding the user profile information in a multi-HSS environment. DH_SLF_QUERY indicates an IMPU and DX_SLF_RESP return the HSS name.

451:

3GPP release 10 added support for inter device transfer, enhancements to the single radio voice call continuity (SRVCC), enhancements to IMS emergency sessions.

1593:

Originate a session on behalf of a user or public service identity, if the AS has no knowledge of a S-CSCF assigned to that user or public service identity

851:

Up to Release 6 it can also be used to hide the internal network from the outside world (encrypting parts of the SIP message), in which case it's called a

804:

It inspects the signaling and ensures that the IMS terminals do not misbehave (e.g. change normal signaling routes, disobey home network's routing policy).

2413: 2038: 738:

Several roles of SIP servers or proxies, collectively called Call Session Control Function (CSCF), are used to process SIP signaling packets in the IMS.

358: 499:

into two or more nodes. Each node can also be present multiple times in a single network, for dimensioning, load balancing or organizational issues.

723: 49: 1341:

Via VGW (VoIP-Gateway) or SIP Gateway/Adapter on customer premises. POTS phones via VOIP Gateway connect to P-CSCF directly. Operators mostly use

1396:

Used by MRFC to fetch documents (e.g. scripts, announcement files, and other resources) from an AS. Also used for media control related commands.

455: 2063: 1988: 1441:

Used by I-CSCF or S-CSCF to find a correct HSS in a multi-HSS environment. DX_SLF_QUERY indicates an IMPU and DX_SLF_RESP return the HSS name.

842:

type of DNS records), so that remote servers can find it, and use it as a forwarding point (e.g., registering) for SIP packets to this domain.

765: 2243: 1128:(ISUP) from the MGCF to the CS network. The SGW does call control protocol conversion between SIP and ISUP/BICC under the control of the MGCF. 2347: 2328: 2309: 2290: 2177: 302:

Alternative and overlapping technologies for access and provisioning of services across wired and wireless networks include combinations of

1984: 1113: 376: 1410:

Used to send subscriber data to the S-CSCF; including filter criteria and their priority. Also used to furnish CDF and/or OCF addresses.

1271:

Rf interface to send accounting information to a CDF located in the same domain. The CDF will collect all this information, and build a

2073: 761: 1281:(ICID) as a unique identifier generated by the first IMS entity involved in a SIP transaction and used for the correlation with CDRs. 246: 480: 1267:

Offline Charging : All the SIP network entities (P-CSCF, I-CSCF, S-CSCF, BGCF, MRFC, MGCF, AS) involved in the session use the

1183:

Media Resources are those components that operate on the media plane and are under the control of IMS core functions. Specifically,

406: 193: 175: 113: 63: 2393: 2383: 1045:

The MRFP is a media plane node used to mix, source or process media streams. It can also manage access right to shared resources.

935: 782:

It sits on the path of all signaling, and can inspect every signal; the IMS terminal must ignore any other unencrypted signaling.

1959:

Trigger point - logical condition(s) which is verified against initial dialog creating SIP requests or stand-alone SIP requests.

1093: 818:(QoS) over the media plane. It is used for policy control, bandwidth management, etc. The PDF can also be a separate function. 2140: 2043: 945: 707:

T-GRUU do not reveal the IMPU and are valid until the contact is explicitly de-registered or the current registration expires

1472:

Allows operators to control QoS in a user plane and exchange charging correlation information between IMS and GPRS network

1255:

are addresses distributed to each IMS entities and provide a common location for each entity to send charging information.

519:

in another network or country (the visited network). The only requirement is that they can use IP and run SIP user agents.

2403: 2068: 426: 292: 1155: 1105: 876: 773: 632: 157: 55: 1873:

Transports CAMEL subscription information, including triggers for use by CAMEL-based application services information.

2408: 1983:

It is envisaged that security defined in TS 33.203 may not be available for a while especially because of the lack of

1346: 948:, and interface with the S-CSCF using SIP. An example of an application server that is being developed in 3GPP is the 860: 645: 624: 620: 619:

of the user, and can provide information about the subscriber's location and IP information. It is similar to the GSM

572: 337: 288: 1996: 830:(I-CSCF) is another SIP function located at the edge of an administrative domain. Its IP address is published in the 756: 2058: 1204: 512: 1790:

Used by the AS to request that media resources be assigned to a call when using MRB in-line mode or in query mode

1112:

A signalling gateway (SGW) interfaces with the signalling plane of the CS. It transforms lower layer protocols as

379:(a different organization from 3GPP) based their CDMA2000 Multimedia Domain (MMD) on 3GPP IMS, adding support for 1342: 1042:

The MRFC is a signalling plane node that interprets information coming from an AS and S-CSCF to control the MRFP

872: 752: 415: 149: 779:

It is assigned to an IMS terminal before registration, and does not change for the duration of the registration.

764:, or it may be configured (e.g. during initial provisioning or via a 3GPP IMS Management Object (MO)) or in the 1142: 901:

it decides to which application server(s) the SIP message will be forwarded, in order to provide their services

790: 422: 1241:

Offline charging is applied to users who pay for their services periodically (e.g., at the end of the month).

855:(THIG). From Release 7 onwards this "entry point" function is removed from the I-CSCF and is now part of the 2418: 2388: 1962:

Application server URI - specifies the application server to be forwarded to when the trigger point matches.

1345:

between VoIP gateways and P-CSCFs for security and to hide network topology. VoIP gateway link to IMS using

898:

it sits on the path of all signaling messages of the locally registered users, and can inspect every message

845:

it queries the HSS to retrieve the address of the S-CSCF and assign it to a user performing SIP registration

544: 524: 219: 414:), fixed broadband connection to the IMS, interworking with non-IMS networks, policy and charging control ( 2423: 2088: 2028: 1246: 1242: 971: 682:(IMPU) is used by any user for requesting communications to other users (e.g. this might be included on a 325: 303: 2428: 2098: 1117: 1101: 1097: 949: 864: 437: 429:, multimedia session continuity, enhanced emergency sessions, SMS over SGs and IMS centralized services. 411: 507:

The user can connect to IMS in various ways, most of which use the standard IP. IMS terminals (such as

2198: 1362: 952:

Function (VCC Server). Depending on the actual service, the AS can operate in SIP proxy mode, SIP UA (

253:. Its original formulation (3GPP Rel-5) represented an approach for delivering Internet services over 1249:

services, or real-time credit control of postpaid services. Both may be applied to the same session.

1226: 1135:(MGCF) is a SIP endpoint that interfaces with the SGW over SCTP. It also controls the resources in a 981: 905: 441: 317: 2398: 1297: 1268: 1167: 1121: 295:(FMC). This is done by having a horizontal control layer that isolates the access network from the 1559:

Used to exchange messages between an IBCF and another IBCF belonging to a different IMS network.

1024: 941: 831: 815: 445: 1573:

Used to forward media streams from a TrGW to another TrGW belonging to a different IMS network.

2363: 2343: 2324: 2305: 2286: 2173: 2164:, Advances in Intelligent and Soft Computing, Berlin, Heidelberg: Springer, pp. 247–254, 1085: 919: 915: 814:

It may include a Policy Decision Function (PDF), which authorizes media plane resources e.g.,

604: 603:(UPSF), is a master user database that supports the IMS network entities that actually handle 227: 2219: 656: 2165: 2048: 868: 238:

technologies are available on smartphones; IMS provides a standard protocol across vendors.

231: 700:

instance. There are two types of GRUU: Public-GRUU (P-GRUU) and Temporary GRUU (T-GRUU).

794: 362: 242: 2281:

The 3G IP multimedia subsystem (IMS) : Merging the Internet and the Cellular Worlds

2279: 1762:

Used for call control services by AGCF to control H.248 A-MGW and residential gateways

1125: 1089: 1057:

Query mode: AS queries the MRB for media and sets up the call using the response of MRB

697: 612: 536: 468: 329: 1901:

Facilitates the management of subscriber information related to services and settings

1859:

AS to activate/deactivate filter criteria stored in the HSS on a per-subscriber basis

650: 17: 2377: 1734:

Used to exchange messages between CSCFs. AGCF appears as a P-CSCF to the other CSCFs

1590:

Forward SIP requests which are destined to a public service identity hosted by the AS

1458:

Used to exchange messages between SIP user equipment (UE) or Voip gateway and P-CSCF

1230: 1191: 1150: 1137: 798: 683: 616: 296: 235: 2259: 1517:

Used for online flow-based bearer charging. Functionally equivalent to Ro interface

2083: 1185: 891:

it handles SIP registrations, which allows it to bind the user location (e.g., the

608: 580: 564: 520: 508: 391: 387: 273: 142: 2169: 1838:

Used to exchange policy and charging related information between P-CSCF and PCRF

2093: 2053: 2033: 2006: 769: 528: 398: 2156: 1154:(MGW) interfaces with the media plane of the CS network, by converting between 226:

services. Historically, mobile phones have provided voice call services over a

953: 892: 839: 405:

release R1.1, the function of AGCF (access gateway control function) and PES (

307: 223: 1486:

Used to exchange policy decisions-related information between P-CSCF and PDF

755:(SBC) for this function. The P-CSCF is at its core a specialized SBC for the 2154:

Zhao, Peng; Wei, Qun; Xia, Hailun; Zeng, Zhimin (2012), Tan, Honghua (ed.),

2002: 1537:

Notify the AS of the registered IMPU, registration state and UE capabilities

1500:

Used to exchange policy decisions-related information between PCEF and PCRF

747: 491:

3GPP / TISPAN IMS architectural overview – HSS in IMS layer (as by standard)

487: 479: 1887:

Used by MRFC to fetch documents (scripts and other resources) from an AS

984:

service capability server (OSA SCS): Interfaces SIP to the OSA framework;

552: 532: 380: 277: 1612:

ISUP signalling to SIP signalling and forwards SIP signalling to I-CSCF

1060:

In-Line Mode: AS sends a SIP INVITE to the MRB. The MRB sets up the call

730:, subscriber service profiles, service triggers, and other information. 1540:

Supply the AS with information to allow it to execute multiple services

1286: 859:(IBCF). The IBCF is used as gateway to external networks, and provides 808: 696:(GRUU) is an identity that identifies a unique combination of IMPU and 516: 515:(PDAs) and computers) can register directly on IMS, even when they are 1696:

Allows an MRFC to control media stream resources provided by an MRFP.

2010: 1335: 727: 548: 402: 265: 1534:

Reference point between S-CSCF and AS. Main functions are to :

249:(3GPP), as a part of the vision for evolving mobile networks beyond 1027:(e.g. voice stream mixing) and playing of tones and announcements. 636:(SLF) is needed to map user addresses when multiple HSSs are used. 458:

simulation service, network-provided location information for IMS,

2118:

Technical Specification Group Services and System Aspects (2006),

1668:

Used for exchanging messages between IMS and external IP networks

1361: 1331: 1171: 1163: 957: 835: 786: 576: 568: 540: 486: 478: 321: 258: 2368: 448:

security, enhancements to services centralization and continuity.

1992: 1082: 560: 462:

submit and delivery without MSISDN in IMS, and overload control.

433: 370: 350: 333: 284: 269: 254: 607:. It contains the subscription-related information (subscriber 1946: 1159: 1100:(MTP), while IMS uses SIP over IP. For media, CS networks use 556: 459: 366: 365:), when SIP-based multimedia was added. Support for the older 250: 125: 70: 29: 2023: 785:

It provides subscriber authentication and may establish an

354: 793:

security association with the IMS terminal. This prevents

432:

3GPP release 9 added support for IMS emergency calls over

1275:(CDR), which is sent to the billing system of the domain. 495:

Each of the functions in the diagram is explained below.

1956:

Priority - determines the order of checking the trigger.

1898:

UE and SIP AS (SIP AS, OSA SCS, IM-SSF) PES AS and AGCF

1804:

Used to exchange offline charging information with CDF

1007:

a distinct PSI contains the PSI that is used in routing

153: 91: 2338:

Wuthnow, Mark; Stafford, Matthew; Shih, Jerry (2010).

1821:

Used to exchange online charging information with OCF

1716:

Used to exchange session controls between AS and MRFC

848:

it also forwards SIP request or response to the S-CSCF

579:

and non IMS-compatible systems, are supported through

2277:

Camarillo, Gonzalo; García-Martín, Miguel A. (2007).

2139:, Mobile Communications International, archived from 811:, which reduces the round-trip over slow radio links. 722:

The HSS subscriber database contains the IMPU, IMPI,

1714:

Used to exchange information between S-CSCF and MRFC

1245:, also known as credit-based charging, is used for 86:

may be too technical for most readers to understand

2302:The IMS : IP multimedia concepts and services 2278: 2155: 2133:Alexander Harrowell, Staff Writer (October 2006), 1991:interfaces and prevalence of devices that support 1979:Security aspects of early IMS and non-3GPP systems 1626:Used to exchange messages between S-CSCF and BGCF 807:It can compress and decompress SIP messages using 654:) or alphanumeric identifiers (a SIP URI, such as 2120:IP Multimedia Subsystem (IMS), Stage 2, TS 23.228 1259:(CDF) addresses are used for offline billing and 1010:a wildcarded PSI represents a collection of PSIs. 914:there can be multiple S-CSCFs in the network for 418:), emergency sessions. It also added SMS over IP. 2340:IMS : A New Model for Blending Applications 230:-style network, rather than strictly over an IP 1088:(CS) networks. For signalling, CS networks use 1023:(MRF) provides media related functions such as 704:P-GRUU reveal the IMPU and are very long lived. 648:(URIs), that can be digits (a Tel URI, such as 2079:SIP extensions for the IP multimedia subsystem 964:SIP AS: Host and execute IMS specific services 911:it enforces the policy of the network operator 904:it provides routing services, typically using 571:) are all supported. Other phone systems like 316:Examples of global standards based on IMS are 1801:P-CSCF, I-CSCF, S-CSCF, BGCF, MRFC, MGCF, AS 1292:Online charging : The S-CSCF talks to a 353:), as part of their standardization work for 27:Architectural framework of telecommunications 8: 1915:Conversion of POTS services to SIP messages 268:by requiring support of networks other than 241:IMS was originally designed by the wireless 2319:Syed A. Ahson, Mohammed Ilyas, ed. (2009). 801:and protects the privacy of the subscriber. 64:Learn how and when to remove these messages 2039:OMA Instant Messaging and Presence Service 719:expresses a set of IMPU grouped together. 361:networks. It first appeared in Release 5 ( 257:. This vision was later updated by 3GPP, 1225:intermediate network domain(s) acting as 194:Learn how and when to remove this message 176:Learn how and when to remove this message 114:Learn how and when to remove this message 98:, without removing the technical details. 2254: 2252: 1840:Replacement for the Gq reference point. 1369: 968:IP Multimedia Service Switching Function 483:3GPP / TISPAN IMS architectural overview 2110: 1776:Reference point between AGCF and CSCF. 1682:Allows control of user-plane resources 1424:AS (SIP AS, OSA, IM-SSF) <-> SLF 1366:TISPAN IMS architecture with interfaces 857:Interconnection Border Control Function 386:3GPP release 6 added interworking with 334:Unstructured Supplementary Service Data 320:which is the basis for Voice over LTE ( 287:protocols wherever possible, e.g., the 2321:IP multimedia subsystem (IMS) handbook 2064:Service capability interaction manager 1912:POTS, Analog phones and VoIP gateways 1218:Connectivity-oriented interconnection 853:Topology Hiding Inter-network Gateway 96:make it understandable to non-experts 7: 2214: 2212: 2122:, 3rd Generation Partnership Project 1665:I-CSCF, S-CSCF, external IP network 1312:event charging with unit reservation 1114:Stream Control Transmission Protocol 895:of the terminal) and the SIP address 734:Call Session Control Function (CSCF) 575:(POTS—the old analogue telephones), 332:(ViLTE), SMS/MMS over WiFi and LTE, 212:IP Multimedia Core Network Subsystem 2162:Knowledge Discovery and Data Mining 1793:SIP, in query mode (not specified) 1030:Each MRF is further divided into a 821:It also generates charging records. 2304:(2 ed.). Chichester : Wiley. 2285:(2 ed.). Chichester : Wiley. 1596:Convey charging function addresses 1543:Convey charging function addresses 1081:A PSTN/CS gateway interfaces with 1032:media resource function controller 401:networks by working together with 247:3rd Generation Partnership Project 25: 2414:Telecommunications infrastructure 2136:A Pointless Multimedia Subsystem? 1438:(I-CSCF or S-CSCF) <-> SLF 1166:don't match (e.g., IMS might use 1162:. It can also transcode when the 1133:media gateway controller function 1071:Breakout Gateway Control Function 1036:media resource function processor 690:Globally Routable User Agent URI: 421:3GPP release 8 added support for 397:3GPP release 7 added support for 45:This article has multiple issues. 1212:Service-oriented interconnection 936:Next generation network services 712:Wildcarded Public User Identity: 694:Globally Routable User Agent URI 363:evolution from 2G to 3G networks 156:, and discuss this issue on the 141:may have confusing or ambiguous 130: 75: 34: 2244:"What is Voice over LTE, VoLTE" 2157:"A New Mechanism of EAB in RCS" 717:wildcarded Public User Identity 664:IP Multimedia Private Identity: 53:or discuss these issues on the 2044:IP connectivity access network 1475:COPS (Rel5), diameter (Rel6+) 1233:signalling and media traffic. 675:IP Multimedia Public Identity: 669:IP Multimedia Private Identity 1: 2260:"3GPP Stage 2 Specifications" 2069:System Architecture Evolution 1966:There are two types of iFCs: 1731:P-CSCF, I-CSCF, S-CSCF, AGCF 1300:Ro interface towards an OCF. 680:IP Multimedia Public Identity 592:HSS – Home subscriber server: 563:) and wireless access (e.g., 2170:10.1007/978-3-642-27708-5_33 1116:(SCTP, an IP protocol) into 1106:Real-time Transport Protocol 970:(IM-SSF): Interfaces SIP to 877:network-to-network interface 774:General Packet Radio Service 633:subscriber location function 601:user profile server function 2199:"3GPP Release Descriptions" 1253:Charging function addresses 834:(DNS) of the domain (using 646:uniform resource identifier 573:plain old telephone service 513:personal digital assistants 373:networks was also provided. 338:Rich Communication Services 289:Session Initiation Protocol 2445: 2300:Poikselkä, Miikka (2007). 2059:Peer-to-peer video sharing 1855:AS (SIP AS, OSA SCS), HSS 1343:session border controllers 1321:IMS-based PES architecture 1263:(OCF) for online billing. 1205:next-generation networking 933: 2342:. Boca Raton: CRC Press. 2323:. Boca Raton: CRC Press. 1283:Inter Operator Identifier 1124:(SS7) protocol), to pass 873:session border controller 753:Session Border Controller 1952:The iFC is composed of: 1385:Technical specification 1305:immediate event charging 1277:Each session carries an 1261:Online Charging Function 657:sip:john.doe@example.com 357:mobile phone systems in 293:fixed-mobile convergence 2394:LTE (telecommunication) 2384:Audio network protocols 1943:initial filter criteria 1937:Initial filter criteria 1587:Main functions are to: 1289:charges can be applied. 1279:IMS Charging Identifier 1203:There are two types of 1021:Media Resource Function 998:Public Service Identity 539:), mobile access (e.g. 525:digital subscriber line 220:architectural framework 208:IP Multimedia Subsystem 2220:"Dispelling LTE Myths" 2089:Ultra Mobile Broadband 2029:Generic Access Network 1997:user–network interface 1407:(I-CSCF, S-CSCF), HSS 1367: 1358:Interfaces description 1257:charging data function 1104:(PCM), while IMS uses 944:(AS) host and execute 757:User–network interface 621:home location register 597:home subscriber server 492: 484: 454:3GPP release 11 added 304:Generic Access Network 18:Home Subscriber Server 2364:A decent IMS tutorial 2099:Voice call continuity 1365: 1118:Message Transfer Part 1102:Pulse-code modulation 1098:Message Transfer Part 1051:Media Resource Broker 950:Voice call continuity 625:Authentication centre 490: 482: 336:(USSD) over LTE, and 2404:Network architecture 1933:respective S-CSCFs. 1609:MGCF -> I,S-CSCF 1584:I-CSCF <-> AS 1531:S-CSCF <-> AS 1294:IMS gateway function 1199:NGN interconnection 974:to communicate with 906:Electronic Numbering 875:specialized for the 442:multimedia telephony 218:) is a standardised 154:improve this article 2242:Ian Poole, editor. 1523:TS23.203, TS32.299 1506:TS29.211, TS29.212 1447:TS29.229, TS29.212 1416:TS29.229, TS29.212 1122:Signalling System 7 978:Application Servers 942:Application servers 930:Application servers 768:or assigned in the 651:tel:+1-555-123-4567 2409:Telecommunications 1623:S-CSCF -> BGCF 1399:TCP/SCTP channels 1368: 1273:call detail record 1025:media manipulation 832:Domain Name System 828:Interrogating-CSCF 816:quality of service 493: 485: 440:, enhancements to 234:network. Various 222:for delivering IP 148:Please review the 2349:978-1-4200-9285-1 2330:978-1-4200-6459-9 2311:978-0-470-01906-1 2292:978-0-470-01818-7 2179:978-3-642-27708-5 1921: 1920: 1818:AS, MRFC, S-CSCF 1207:interconnection: 1170:, PSTN might use 920:high availability 916:load distribution 871:). The IBCF is a 310:and "naked" SIP. 280:and fixed lines. 204: 203: 196: 186: 185: 178: 124: 123: 116: 68: 16:(Redirected from 2436: 2353: 2334: 2315: 2296: 2284: 2264: 2263: 2256: 2247: 2240: 2234: 2233: 2231: 2230: 2216: 2207: 2206: 2195: 2189: 2188: 2187: 2186: 2159: 2151: 2145: 2144: 2130: 2124: 2123: 2115: 2049:Mobile broadband 1924:Session handling 1745:BGCF/CSCF, IBCF 1651:BGCF -> BGCF 1637:BGCF -> MGCF 1370: 1227:transit networks 1141:(MGW) across an 1086:circuit switched 1065:Breakout gateway 989:Functional model 795:spoofing attacks 640:User identities: 228:circuit-switched 199: 192: 181: 174: 170: 167: 161: 134: 133: 126: 119: 112: 108: 105: 99: 79: 78: 71: 60: 38: 37: 30: 21: 2444: 2443: 2439: 2438: 2437: 2435: 2434: 2433: 2374: 2373: 2360: 2350: 2337: 2331: 2318: 2312: 2299: 2293: 2276: 2273: 2271:Further reading 2268: 2267: 2258: 2257: 2250: 2241: 2237: 2228: 2226: 2218: 2217: 2210: 2197: 2196: 2192: 2184: 2182: 2180: 2153: 2152: 2148: 2132: 2131: 2127: 2117: 2116: 2112: 2107: 2020: 2007:PacketCable 2.0 1981: 1939: 1926: 1715: 1710: 1705: 1373:Interface name 1360: 1323: 1276: 1243:Online charging 1239: 1201: 1181: 1179:Media resources 1079: 1067: 1017: 1000: 991: 938: 932: 736: 714: 692: 677: 666: 642: 594: 589: 505: 477: 346: 232:packet-switched 200: 189: 188: 187: 182: 171: 165: 162: 150:Manual of Style 147: 135: 131: 120: 109: 103: 100: 92:help improve it 89: 80: 76: 39: 35: 28: 23: 22: 15: 12: 11: 5: 2442: 2440: 2432: 2431: 2426: 2421: 2419:Videotelephony 2416: 2411: 2406: 2401: 2396: 2391: 2389:3GPP standards 2386: 2376: 2375: 2372: 2371: 2369:IMS Call Flows 2366: 2359: 2358:External links 2356: 2355: 2354: 2348: 2335: 2329: 2316: 2310: 2297: 2291: 2272: 2269: 2266: 2265: 2248: 2235: 2208: 2190: 2178: 2146: 2125: 2109: 2108: 2106: 2103: 2102: 2101: 2096: 2091: 2086: 2081: 2076: 2071: 2066: 2061: 2056: 2051: 2046: 2041: 2036: 2031: 2026: 2019: 2016: 1980: 1977: 1976: 1975: 1972: 1964: 1963: 1960: 1957: 1938: 1935: 1925: 1922: 1919: 1918: 1916: 1913: 1910: 1906: 1905: 1904:HTTP(s), XCAP 1902: 1899: 1896: 1892: 1891: 1888: 1885: 1882: 1878: 1877: 1874: 1871: 1868: 1864: 1863: 1860: 1856: 1853: 1849: 1848: 1845: 1842: 1836: 1833: 1829: 1828: 1825: 1822: 1819: 1816: 1812: 1811: 1808: 1805: 1802: 1799: 1795: 1794: 1791: 1788: 1785: 1781: 1780: 1777: 1774: 1771: 1767: 1766: 1763: 1760: 1757: 1753: 1752: 1749: 1746: 1743: 1739: 1738: 1735: 1732: 1729: 1725: 1724: 1721: 1717: 1712: 1707: 1701: 1700: 1697: 1694: 1691: 1687: 1686: 1683: 1680: 1677: 1673: 1672: 1669: 1666: 1663: 1659: 1658: 1655: 1652: 1649: 1645: 1644: 1641: 1638: 1635: 1631: 1630: 1627: 1624: 1621: 1617: 1616: 1613: 1610: 1607: 1603: 1602: 1599: 1598: 1597: 1594: 1591: 1585: 1582: 1578: 1577: 1574: 1571: 1568: 1564: 1563: 1560: 1557: 1554: 1550: 1549: 1546: 1545: 1544: 1541: 1538: 1532: 1529: 1525: 1524: 1521: 1518: 1515: 1512: 1508: 1507: 1504: 1501: 1498: 1495: 1491: 1490: 1487: 1484: 1481: 1477: 1476: 1473: 1470: 1467: 1463: 1462: 1459: 1456: 1453: 1449: 1448: 1445: 1442: 1439: 1436: 1432: 1431: 1428: 1425: 1422: 1418: 1417: 1414: 1411: 1408: 1405: 1401: 1400: 1397: 1394: 1391: 1387: 1386: 1383: 1380: 1377: 1374: 1359: 1356: 1352: 1351: 1339: 1322: 1319: 1318: 1317: 1316: 1315: 1308: 1290: 1238: 1235: 1222: 1221: 1215: 1200: 1197: 1180: 1177: 1176: 1175: 1146: 1129: 1126:ISDN User Part 1090:ISDN User Part 1078: 1075: 1066: 1063: 1062: 1061: 1058: 1047: 1046: 1043: 1016: 1013: 1012: 1011: 1008: 999: 996: 990: 987: 986: 985: 979: 965: 956:) mode or SIP 931: 928: 927: 926: 925: 924: 912: 909: 908:(ENUM) lookups 902: 899: 896: 882: 881: 880: 849: 846: 824: 823: 822: 819: 812: 805: 802: 799:replay attacks 783: 780: 746:(P-CSCF) is a 735: 732: 709: 708: 705: 613:authentication 588: 585: 504: 503:Access network 501: 476: 473: 469:Voice over LTE 464: 463: 452: 449: 430: 419: 395: 384: 374: 345: 342: 330:Video over LTE 202: 201: 184: 183: 138: 136: 129: 122: 121: 83: 81: 74: 69: 43: 42: 40: 33: 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 2441: 2430: 2427: 2425: 2424:Voice over IP 2422: 2420: 2417: 2415: 2412: 2410: 2407: 2405: 2402: 2400: 2397: 2395: 2392: 2390: 2387: 2385: 2382: 2381: 2379: 2370: 2367: 2365: 2362: 2361: 2357: 2351: 2345: 2341: 2336: 2332: 2326: 2322: 2317: 2313: 2307: 2303: 2298: 2294: 2288: 2283: 2282: 2275: 2274: 2270: 2261: 2255: 2253: 2249: 2245: 2239: 2236: 2225: 2221: 2215: 2213: 2209: 2204: 2200: 2194: 2191: 2181: 2175: 2171: 2167: 2163: 2158: 2150: 2147: 2143:on 2010-09-18 2142: 2138: 2137: 2129: 2126: 2121: 2114: 2111: 2104: 2100: 2097: 2095: 2092: 2090: 2087: 2085: 2082: 2080: 2077: 2075: 2072: 2070: 2067: 2065: 2062: 2060: 2057: 2055: 2052: 2050: 2047: 2045: 2042: 2040: 2037: 2035: 2032: 2030: 2027: 2025: 2022: 2021: 2017: 2015: 2012: 2008: 2004: 2000: 1998: 1994: 1990: 1986: 1978: 1973: 1969: 1968: 1967: 1961: 1958: 1955: 1954: 1953: 1950: 1948: 1944: 1936: 1934: 1930: 1923: 1917: 1914: 1911: 1908: 1907: 1903: 1900: 1897: 1894: 1893: 1889: 1886: 1883: 1880: 1879: 1875: 1872: 1869: 1866: 1865: 1861: 1857: 1854: 1851: 1850: 1846: 1843: 1841: 1837: 1835:P-CSCF, PCRF 1834: 1831: 1830: 1826: 1823: 1820: 1817: 1814: 1813: 1809: 1806: 1803: 1800: 1797: 1796: 1792: 1789: 1786: 1783: 1782: 1778: 1775: 1772: 1769: 1768: 1764: 1761: 1758: 1755: 1754: 1750: 1747: 1744: 1741: 1740: 1736: 1733: 1730: 1727: 1726: 1722: 1718: 1713: 1708: 1703: 1702: 1698: 1695: 1692: 1689: 1688: 1684: 1681: 1679:MGCF, IM-MGW 1678: 1675: 1674: 1670: 1667: 1664: 1661: 1660: 1656: 1653: 1650: 1647: 1646: 1642: 1639: 1636: 1633: 1632: 1628: 1625: 1622: 1619: 1618: 1614: 1611: 1608: 1605: 1604: 1600: 1595: 1592: 1589: 1588: 1586: 1583: 1580: 1579: 1575: 1572: 1569: 1566: 1565: 1561: 1558: 1555: 1552: 1551: 1547: 1542: 1539: 1536: 1535: 1533: 1530: 1527: 1526: 1522: 1519: 1516: 1513: 1510: 1509: 1505: 1502: 1499: 1496: 1493: 1492: 1488: 1485: 1482: 1479: 1478: 1474: 1471: 1468: 1465: 1464: 1460: 1457: 1454: 1451: 1450: 1446: 1443: 1440: 1437: 1434: 1433: 1429: 1426: 1423: 1420: 1419: 1415: 1412: 1409: 1406: 1403: 1402: 1398: 1395: 1392: 1389: 1388: 1384: 1381: 1378: 1376:IMS entities 1375: 1372: 1371: 1364: 1357: 1355: 1348: 1344: 1340: 1337: 1333: 1329: 1328: 1327: 1320: 1313: 1309: 1306: 1302: 1301: 1299: 1295: 1291: 1288: 1284: 1280: 1274: 1270: 1266: 1265: 1264: 1262: 1258: 1254: 1250: 1248: 1244: 1236: 1234: 1232: 1231:service layer 1228: 1219: 1216: 1213: 1210: 1209: 1208: 1206: 1198: 1196: 1194: 1193: 1192:Media gateway 1188: 1187: 1178: 1173: 1169: 1165: 1161: 1157: 1153: 1152: 1151:media gateway 1147: 1144: 1140: 1139: 1138:Media Gateway 1134: 1130: 1127: 1123: 1119: 1115: 1111: 1110: 1109: 1107: 1103: 1099: 1095: 1091: 1087: 1084: 1077:PSTN gateways 1076: 1074: 1072: 1064: 1059: 1056: 1055: 1054: 1052: 1044: 1041: 1040: 1039: 1037: 1034:(MRFC) and a 1033: 1028: 1026: 1022: 1015:Media servers 1014: 1009: 1006: 1005: 1004: 997: 995: 988: 983: 980: 977: 973: 969: 966: 963: 962: 961: 959: 955: 951: 947: 943: 937: 929: 921: 917: 913: 910: 907: 903: 900: 897: 894: 890: 889: 887: 883: 878: 874: 870: 866: 862: 858: 854: 850: 847: 844: 843: 841: 837: 833: 829: 825: 820: 817: 813: 810: 806: 803: 800: 796: 792: 788: 784: 781: 778: 777: 775: 771: 767: 763: 758: 754: 749: 745: 741: 740: 739: 733: 731: 729: 725: 720: 718: 713: 706: 703: 702: 701: 699: 695: 691: 687: 685: 684:business card 681: 676: 672: 670: 665: 661: 660: 658: 653: 652: 647: 641: 637: 635: 634: 628: 626: 622: 618: 617:authorization 614: 610: 606: 602: 598: 593: 586: 584: 582: 578: 574: 570: 566: 562: 558: 554: 550: 546: 542: 538: 534: 530: 526: 522: 518: 514: 510: 509:mobile phones 502: 500: 496: 489: 481: 474: 472: 470: 461: 457: 453: 450: 447: 443: 439: 435: 431: 428: 424: 420: 417: 413: 408: 404: 400: 396: 393: 389: 385: 382: 378: 375: 372: 368: 364: 360: 356: 352: 348: 347: 343: 341: 339: 335: 331: 327: 326:Wi-Fi Calling 323: 319: 314: 311: 309: 305: 300: 298: 297:service layer 294: 290: 286: 281: 279: 275: 271: 267: 264: 260: 256: 252: 248: 244: 239: 237: 236:voice over IP 233: 229: 225: 221: 217: 213: 209: 198: 195: 180: 177: 169: 159: 155: 151: 145: 144: 143:abbreviations 139:This article 137: 128: 127: 118: 115: 107: 104:December 2010 97: 93: 87: 84:This article 82: 73: 72: 67: 65: 58: 57: 52: 51: 46: 41: 32: 31: 19: 2429:IMS services 2339: 2320: 2301: 2280: 2238: 2227:. Retrieved 2224:www.3gpp.org 2223: 2202: 2193: 2183:, retrieved 2161: 2149: 2141:the original 2135: 2128: 2119: 2113: 2084:Text over IP 2001: 1982: 1965: 1951: 1945:(iFC) is an 1942: 1940: 1931: 1927: 1870:IM-SSF, HSS 1839: 1759:AGCF, A-MGW 1709:S-CSCF, MRFC 1483:P-CSCF, PDF 1379:Description 1353: 1324: 1311: 1304: 1293: 1282: 1278: 1272: 1260: 1256: 1252: 1251: 1240: 1223: 1217: 1211: 1202: 1190: 1186:Media Server 1184: 1182: 1149: 1136: 1132: 1080: 1070: 1068: 1050: 1048: 1035: 1031: 1029: 1020: 1018: 1001: 992: 967: 939: 886:Serving-CSCF 885: 856: 852: 827: 743: 737: 721: 716: 711: 710: 693: 689: 688: 679: 674: 673: 668: 663: 662: 655: 649: 639: 638: 631: 629: 611:), performs 600: 596: 591: 590: 587:Core network 529:cable modems 521:Fixed access 506: 497: 494: 475:Architecture 465: 392:Push to talk 315: 312: 308:softswitches 301: 282: 274:Wireless LAN 240: 215: 211: 207: 205: 190: 172: 163: 140: 110: 101: 85: 61: 54: 48: 47:Please help 44: 2094:Video share 2054:Mobile VoIP 2034:Image share 1773:AGCF, CSCF 1693:MRFC, MRFP 1497:PCEF, PCRF 1455:UE, P-CSCF 1092:(ISUP) (or 867:functions ( 770:PDP Context 446:media plane 2399:Multimedia 2378:Categories 2229:2021-04-08 2185:2021-04-08 2105:References 1514:PCEF, OCS 1469:PDF, GGSN 1145:interface. 954:user agent 934:See also: 893:IP address 744:Proxy-CSCF 623:(HLR) and 599:(HSS), or 328:(VoWIFI), 272:, such as 224:multimedia 50:improve it 2003:CableLabs 1884:MRFC, AS 1862:Diameter 1847:TS29.214 1844:Diameter 1827:TS32.299 1824:Diameter 1810:TS32.299 1807:Diameter 1711:AS, MRFC 1520:Diameter 1503:Diameter 1489:Diameter 1444:Diameter 1430:Diameter 1413:Diameter 1393:MRFC, AS 1382:Protocol 1350:terminal. 1189:(MS) and 869:pinholing 776:(GPRS)). 748:SIP proxy 471:(VoLTE). 283:IMS uses 243:standards 158:talk page 56:talk page 2018:See also 1787:MRB, AS 1298:Diameter 1269:Diameter 1237:Charging 1120:(MTP, a 1038:(MRFP). 946:services 923:S-CSCFs. 865:firewall 609:profiles 581:gateways 553:CDMA2000 533:Ethernet 381:CDMA2000 278:CDMA2000 166:May 2011 1287:roaming 1247:prepaid 1108:(RTP). 1096:) over 809:SigComp 627:(AuC). 527:(DSL), 523:(e.g., 517:roaming 344:History 152:, help 90:Please 2346: 2327: 2308: 2289: 2176: 2074:SIMPLE 2011:TISPAN 1765:H.248 1699:H.248 1685:H.248 1570:TrGWs 1556:IBCFs 1336:Megaco 1195:(MGW) 1164:codecs 879:(NNI). 728:MSISDN 549:W-CDMA 444:, IMS 403:TISPAN 266:TISPAN 1971:CSCF. 1890:HTTP 1332:H.248 1310:When 1303:When 1172:G.711 1143:H.248 976:CAMEL 958:B2BUA 836:NAPTR 787:IPsec 659:" ). 605:calls 577:H.323 569:WiMAX 541:5G NR 399:fixed 377:3GPP2 322:VoLTE 318:MMTel 259:3GPP2 245:body 2344:ISBN 2325:ISBN 2306:ISBN 2287:ISBN 2203:3GPP 2174:ISBN 1993:IPv4 1989:ISIM 1985:USIM 1876:MAP 1779:SIP 1751:SIP 1737:SIP 1723:SIP 1706:Mr' 1671:SIP 1657:SIP 1643:SIP 1629:SIP 1615:SIP 1601:SIP 1576:RTP 1567:Izi 1562:SIP 1553:Ici 1548:SIP 1528:ISC 1461:SIP 1334:.1 ( 1158:and 1094:BICC 1083:PSTN 1049:The 1019:The 940:SIP 918:and 863:and 838:and 797:and 772:(in 766:ISIM 762:DHCP 724:IMSI 678:The 667:The 615:and 595:The 565:WLAN 561:GPRS 537:FTTx 456:USSD 436:and 434:GPRS 407:PSTN 388:WLAN 371:GPRS 369:and 359:UMTS 351:3GPP 285:IETF 270:GPRS 263:ETSI 261:and 255:GPRS 206:The 2166:doi 2005:in 1947:XML 1941:An 1895:Ut 1881:Sr 1867:Si 1852:Sh 1832:Rx 1815:Ro 1798:Rf 1784:Rc 1770:P2 1756:P1 1742:Mx 1728:Mw 1690:Mp 1676:Mn 1662:Mm 1648:Mk 1634:Mj 1620:Mi 1606:Mg 1581:Ma 1511:Gy 1494:Gx 1480:Gq 1466:Go 1452:Gm 1435:Dx 1421:Dh 1404:Cx 1390:Cr 1347:SIP 1168:AMR 1160:PCM 1156:RTP 982:OSA 972:CAP 861:NAT 840:SRV 826:An 791:TLS 789:or 557:GSM 545:LTE 460:SMS 438:EPS 427:SAE 423:LTE 416:PCC 412:VCC 367:GSM 324:), 251:GSM 216:IMS 210:or 94:to 2380:: 2251:^ 2222:. 2211:^ 2201:. 2172:, 2160:, 2024:4G 1999:. 1909:z 1704:Mr 1174:). 1148:A 1131:A 1069:A 884:A 742:A 726:, 715:A 698:UE 630:A 583:. 567:, 559:, 555:, 551:, 547:, 543:, 535:, 531:, 511:, 425:/ 394:). 355:3G 306:, 276:, 59:. 2352:. 2333:. 2314:. 2295:. 2262:. 2246:. 2232:. 2205:. 2168:: 1987:/ 383:. 214:( 197:) 191:( 179:) 173:( 168:) 164:( 160:. 146:. 117:) 111:( 106:) 102:( 88:. 66:) 62:( 20:)

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Index