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40-591: SAE is the evolution of the GPRS Core Network , but with a simplified architecture; an all-IP Network (AIPN); support for higher throughput and lower latency radio access networks (RANs); and support for, and mobility between, multiple heterogeneous access networks, including E-UTRA ( LTE and LTE Advanced air interface), and 3GPP legacy systems (for example GERAN or UTRAN , air interfaces of GPRS and UMTS respectively), but also non-3GPP systems (for example Wi-Fi , WiMAX or CDMA2000 ). The SAE has

80-470: A "ready-to-use" IP connectivity and an "always-on" experience by linking between mobility management and session management procedures during the UE attach procedure. Complete NAS transactions consist of specific sequences of elementary procedures with EPS Mobility Management (EMM) and EPS Session Management (ESM) protocols. The EPS (Evolved Packet System) Mobility Management (EMM) protocol provides procedures for

120-455: A 2G connection and all GAN enabled devices are dual-mode 2G/Wi-Fi. The specification, though, defined support for multimode handset operation. Therefore, 3G/2G/Wi-Fi handsets are supported in the standard. The first 3G/UMA devices were announced in the second half of 2008. A typical UMA/GAN handset will have four modes of operation: In all cases, the handset scans for GSM cells when it first turns on, to determine its location area. This allows

160-468: A default EPS bearer context. The EPS session management messages for the default EPS bearer context activation are transmitted in an information element in the EPS mobility management messages. The UE and network complete the combined default EPS bearer context activation procedure and the attach procedure before the dedicated EPS bearer context activation procedure is completed. The success of the attach procedure

200-659: A flat, all-IP architecture with separation of control plane and user plane traffic. The main component of the SAE architecture is the Evolved Packet Core ( EPC ), also known as SAE Core . The EPC will serve as the equivalent of GPRS networks (via the Mobility Management Entity , Serving Gateway and PDN Gateway subcomponents). The subcomponents of the EPC are: The MME is the key control-node for

240-407: A group of operator and vendor companies. The initial specifications were published on 2 September 2004. The companies then contributed the specifications to the 3rd Generation Partnership Project (3GPP) as part of 3GPP work item "Generic Access to A/Gb interfaces". On 8 April 2005, 3GPP approved specifications for Generic Access to A/Gb interfaces for 3GPP Release 6 and renamed the system to GAN. But

280-521: A network access point over the internet, rather than over-the-air using GSM / GPRS , UMTS or similar. A separate device known as a "GAN Controller" (GANC) receives this data from the Internet and feeds it into the phone network as if it were coming from an antenna on a tower. Calls can be placed from or received to the handset as if it were connected over-the-air directly to the GANC's point of presence ;

320-465: Is activated when the UE requests a connection to a PDN. The first default EPS bearer context, is activated during the EPS attach procedure. Additionally, the network can activate one or several dedicated EPS bearer contexts in parallel. Generally, ESM procedures can be performed only if an EMM context has been established between the UE and the MME, and the secure exchange of NAS messages has been initiated by

360-463: Is based on pre-Rel-4 Home Location Register (HLR) and Authentication Center (AuC). The ANDSF provides information to the UE about connectivity to 3GPP and non-3GPP access networks (such as Wi-Fi). The purpose of the ANDSF is to assist the UE to discover the access networks in their vicinity and to provide rules (policies) to prioritize and manage connections to these networks. The main function of

400-533: Is dependent on the success of the default EPS bearer context activation procedure. If the attach procedure fails, then the ESM session management procedures also fails. The EPS Session Management (ESM) protocol provides procedures for the handling of EPS bearer contexts. Together with the bearer control provided by the Access Stratum , it provides the control of user plane bearers. The transmission of ESM messages

440-431: Is named or VoWiFi by a number of handset manufacturers, including Apple and Samsung , a move that is being mirrored by carriers like T-Mobile US and Vodafone . The service is dependent on IMS, IPsec, IWLAN and ePDG . The original Release 6 GAN specification supported a 2G (A/Gb) connection from the GANC into the mobile core network (MSC/GSN). Today all commercial GAN dual-mode handset deployments are based on

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480-409: Is nearly always associated with dual-mode GSM/Wi-Fi services, it is actually a ‘generic’ access network technology that provides a generic method for extending the services and applications in an operator's mobile core (voice, data, IMS) over IP and the public Internet. GAN defines a secure, managed connection from the mobile core (GANC) to different devices/access points over IP. UMA was developed by

520-525: Is not the first system to allow the use of unlicensed spectrum to connect handsets to a GSM network. The GIP/IWP standard for DECT provides similar functionality, but requires a more direct connection to the GSM network from the base station. While dual-mode DECT/GSM phones have appeared, these have generally been functionally cordless phones with a GSM handset built-in (or vice versa, depending on your point of view), rather than phones implementing DECT/GIP, due to

560-458: Is nothing preventing an operator from deploying micro- and pico-cells that use towers that connect with the home network over the Internet. Several companies have developed femtocell systems that do precisely that, broadcasting a "real" GSM or UMTS signal, bypassing the need for special handsets that require 802.11 technology. In theory, such systems are more universal, and again require lower power than 802.11, but their legality will vary depending on

600-441: Is suspended during EMM procedures except for the attach procedure. EPS Bearer: Each EPS bearer context represents an EPS bearer between the UE and a PDN. EPS bearer contexts can remain activated even if the radio and S1 bearers constituting the corresponding EPS bearers between UE and MME are temporarily released. An EPS bearer context can be either a default bearer context or a dedicated bearer context. A default EPS bearer context

640-515: The Home Subscriber Server ). The Non Access Stratum (NAS) signaling terminates at the MME and it is also responsible for generation and allocation of temporary identities to UEs. It checks the authorization of the UE to camp on the service provider's Public Land Mobile Network (PLMN) and enforces UE roaming restrictions. The MME is the termination point in the network for ciphering/integrity protection for NAS signaling and handles

680-535: The cell towers provided by cellular networks . Using this feature, compatible handsets are able to route regular cellular calls through a wireless LAN (Wi-Fi) network with broadband Internet , while seamlessly change connections between the two where necessary. This feature makes use of the Generic Access Network ( GAN ) protocol, also known as Unlicensed Mobile Access ( UMA ). Essentially, GAN/UMA allows cell phone packets to be forwarded to

720-633: The ECM-IDLE, ECM CONNECTED and EMM-DEREGISTERED states. The MME protocol stack consists of: MME supports the S1 interface with eNodeB. The integrated S1 MME interface stack consists of IP , SCTP , S1AP. MME supports S11 interface with Serving Gateway. The integrated S11 interface stack consists of IP , UDP , eGTP-C . The SGW consists of SGW supports S11 interface with MME and S5/S8 interface with PGW. The integrated control plane stack for these interfaces consists of IP , UDP , eGTP-C . SGW supports

760-526: The GAN system works over the internet, a UMA-capable handset can connect to its service provider from any location with internet access. This is particularly useful for travellers, who can connect to their provider's GANC and make calls into their home service area from anywhere in the world. This is subject to the quality of the internet connection, however, and may not work well over limited bandwidth or long-latency connection. To improve quality of service (QoS) in

800-764: The IP bearer service, network internal routing information. It also performs replication of the user traffic in case of lawful interception. The Packet Data Network Gateway (PDN Gateway, also PGW) provides connectivity from the User Equipment (UE) to external packet data networks (PDNs) by being its point of exit and entry of traffic. A piece of User Equipment may have simultaneous connectivity with more than one Packet Data Network Gateway for accessing multiple packet data networks. The PDN Gateway performs policy enforcement, packet filtering for each user, charging support, lawful interception and packet screening. Another key role of

840-542: The LTE access-network. It is responsible for idle mode User Equipment (UE) paging and tagging procedure including retransmissions. It is involved in the bearer activation/deactivation process and is also responsible for choosing the Serving Gateway for a UE at the initial attach and at time of intra-LTE handover involving Core Network (CN) node relocation. It is responsible for authenticating the user (by interacting with

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880-590: The MME by use of the EMM procedures. Once the UE is successfully attached, the UE can request the MME to set up connections to additional PDNs. For each additional connection, the MME activates a separate default EPS bearer context. A default EPS bearer context remains activated throughout the lifetime of the connection to the PDN. Types of ESM procedures: ESM involves different types of procedures such as: The MME maintains EMM context and EPS bearer context information for UEs in

920-551: The Packet Data Network Gateway is to act as the anchor for mobility between 3GPP and non-3GPP technologies such as WiMAX and 3GPP2 (CDMA 1X and EvDO ). The Home Subscriber Server is a central database that contains user-related and subscription-related information. The functions of the HSS include mobility management, call and session establishment support, user authentication and access authorization. The HSS

960-587: The S1-U interface with eNodeB and S5/S8 data plane interface with PGW. The integrated data plane stack for these interfaces consists of IP , UDP , eGTP-U . Main interfaces supported by the P-GW are: The EPC is a packet-only core network. It does not have a circuit-switched domain, which is traditionally used for phone calls and SMS . 3GPP specified two solutions for voice: 3GPP specified three solutions for SMS: CSFB and SMS over SGs are seen as interim solutions,

1000-451: The UE and the session management procedures to establish and maintain IP connectivity between the UE and a PDN GW. They define the rules for a mapping between parameters during inter-system mobility with 3G networks or non-3GPP access networks. They also provide the NAS security by integrity protection and ciphering of NAS signaling messages. EPS (Evolved Packet System) provides the subscriber with

1040-983: The UK initially on the Nokia Lumia 640 and Samsung Galaxy S6 and Samsung Galaxy S6 Edge handsets. In March 2016, Vodafone Netherlands launched Wi-Fi Calling support along with VoLTE . Since the Autumn of 2016, Wifi Calling / Voice over Wifi has been available for customers of Telenor Denmark, including the ability to do handover to and from the 4G (VoLTE) network. This is available for several Samsung and Apple handsets. AT&T and Verizon are going to launch Wi-Fi calling in 2015. Industry organisation UMA Today tracks all operator activities and handset development. In September 2015, South African cellular network Cell C launched WiFi Calling on its South African network. In November 2024, Belgian cellular network Voo launched WiFi Calling on its Belgian network. GAN/UMA

1080-659: The UK. The announcement, the largest to date, covers more than 60m of Orange's mobile subscribers in the UK, France, Poland, Spain and the Netherlands. Cincinnati Bell announced the first UMA deployment in the United States. The service, originally called CB Home Run, allows users to transfer seamlessly from the Cincinnati Bell cellular network to a home wireless network or to Cincinnati Bell's WiFi HotSpots. It has since been rebranded as Fusion WiFi. This

1120-496: The Wikimedia System Administrators, please include the details below. Request from 172.68.168.133 via cp1102 cp1102, Varnish XID 553388705 Upstream caches: cp1102 int Error: 429, Too Many Requests at Thu, 28 Nov 2024 05:55:34 GMT Wi-Fi calling Wi-Fi calling , also called VoWiFi , refers to mobile phone voice calls and data that are made over IP networks using Wi-Fi , instead of

1160-444: The carrier to route the call to the nearest GANC, set the correct rate plan, and comply with existing roaming agreements. At the end of 2007, the GAN specification was enhanced to support 3G (Iu) interfaces from the GANC to the mobile core network (MSC/GSN). This native 3G interface can be used for dual-mode handset as well as 3G femtocell service delivery. The GAN release 8 documentation describes these new capabilities. While UMA

1200-511: The control of mobility when the User Equipment (UE) uses the Evolved UMTS Terrestrial Radio Access Network (E-UTRAN). It also provides control of security for the NAS protocols. EMM involves different types of procedures such as: The UE and the network execute the attach procedure, the default EPS bearer context activation procedure in parallel. During the EPS attach procedure the network activates

1240-403: The ePDG is to secure the data transmission with a UE connected to the EPC over untrusted non-3GPP access, e.g. Wi-Fi calling ( VoWiFi ). For this purpose, the ePDG acts as a termination node of IPsec tunnels established with the UE. The Non-Access Stratum (NAS) protocols form the highest stratum of the control plane between the user equipment (UE) and MME. NAS protocols support the mobility of

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1280-592: The home or office, some providers also supply a specially programmed wireless access point that prioritizes UMA packets. Another benefit of Wi-Fi calling is that mobile calls can be made through the internet using the same native calling client; it does not require third-party Voice over IP (VoIP) closed services like WhatsApp or Skype , relying instead on the mobile cellular operator. The GAN protocol that extends mobile voice, data and multimedia ( IP Multimedia Subsystem / Session Initiation Protocol (IMS/SIP)) applications over IP networks. The latest generation system

1320-404: The lack of suitable infrastructure to hook DECT base-stations supporting GIP to GSM networks on an ad-hoc basis. GAN/UMA's ability to use the Internet to provide the "last mile" connection to the GSM network solves the major issue that DECT/GIP has faced. Had GIP emerged as a practical standard, the low power usage of DECT technology when idle would have been an advantage compared to GAN. There

1360-540: The long term being IMS . The UE can connect to the EPC using several access technologies. These access technologies are composed of: It is up to the network operator to decide whether a non-3GPP access technology is trusted or untrusted. It is worth noting that these trusted/untrusted categories do not apply to 3GPP accesses. The 3GPP delivers standards in parallel releases, which compose consistent sets of specifications and features. 03056876920 GPRS Core Network Too Many Requests If you report this error to

1400-458: The mobility anchor for the user plane during inter- eNodeB handovers and as the anchor for mobility between LTE and other 3GPP technologies (terminating S4 interface and relaying the traffic between 2G/3G systems and Packet Data Network Gateway). For idle state User Equipment, the Serving Gateway terminates the downlink data path and triggers paging when downlink data arrives for the User Equipment. It manages and stores UE contexts, e.g. parameters of

1440-557: The security key management. Lawful interception of signaling is also supported by the MME. The MME also provides the control plane function for mobility between LTE and 2G/3G access networks with the S3 interface terminating at the MME from the SGSN . The MME also terminates the S6a interface towards the HSS for roaming UEs. The Serving Gateway routes and forwards user data packets, while also acting as

1480-402: The system is essentially invisible to the network as a whole. This can be useful in locations with poor cell coverage where some other form of internet access is available, especially at the home or office. The system offers seamless handoff , so the user can move from cell to Wi-Fi and back again with the same invisibility that the cell network offers when moving from tower to tower. Since

1520-443: The term GAN is little known outside the 3GPP community, and the term UMA is more common in marketing. For carriers: For subscribers: The first service launch was BT with BT Fusion in the autumn of 2005. The service is based on pre-3GPP GAN standard technology. Initially, BT Fusion used UMA over Bluetooth with phones from Motorola . From January 2007, it used UMA over 802.11 with phones from Nokia, Motorola and Samsung and

1560-469: Was branded as a "Wi-Fi mobile service". BT has since discontinued the service. On August 28, 2006, TeliaSonera was the first to launch an 802.11 based UMA service called "Home Free". The service started in Denmark but is no longer offered. On September 25, 2006 Orange announced its "Unik service", also known as Signal Boost in the UK. However this service is no longer available to new customers in

1600-734: Was followed shortly by T-Mobile US on June 27, 2007. T-Mobile's service, originally named "Hotspot Calling", and rebranded to "Wi-Fi Calling" in 2009, allows users to seamlessly transfer from the T-Mobile cellular network to an 802.11x wireless network or T-Mobile HotSpot in the United States. In Canada, both Fido and Rogers Wireless launched UMA plans under the names UNO and Rogers Home Calling Zone (later rebranded Talkspot, and subsequently rebranded again as Wi-Fi Calling), respectively, on May 6, 2008. In Australia, GAN has been implemented by Vodafone, Optus and Telstra. Since 10 April 2015, Wi-Fi Calling has been available for customers of EE in

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