System Architecture Evolution
Encyclopedia
System Architecture Evolution (aka SAE) is the core network architecture of 3GPP
's LTE
wireless communication standard.
SAE is the evolution of the GPRS Core Network
, with some differences:
The main component of the SAE architecture is the Evolved Packet Core (EPC), also known as SAE Core. The EPC will serve as equivalent of GPRS networks (via the Mobility Management Entity, Serving Gateway and PDN Gateway subcomponents).
The subcomponents of the EPC are:
Complete NAS transactions consist of specific sequences of elementary procedures with EPS Mobility Management (EMM) and EPS Session Management (ESM) protocols.
EMM involves different types of procedures such as:
Service request: Initiated by the UE and used to establish a secure connection to the network or to request the resource reservation for sending data, or both.
Paging procedure: Initiated by the network and used to request the establishment of a NAS signalling connection or to prompt the UE to re-attach if necessary as a result of a network failure.
Transport of NAS messages: Initiated by the UE or the network and used to transport NAS messages.
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 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 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.
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 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 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 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.
SCTP (Stream Control Transmission Protocol) is a common transport protocol that uses the services of Internet Protocol (IP) to provide a reliable datagram delivery service to the adaptation modules, such as the S1AP. SCTP provides reliable and sequenced delivery on top of the existing IP framework. The main features provided by SCTP are:
Association setup: An association is a connection that is set up between two endpoints for data transfer, much like a TCP connection. A SCTP association can have multiple addresses at each end.
Reliable Data Delivery: Delivers sequenced data in a stream (Elimination of head-of-line blocking): SCTP ensures the sequenced delivery of data with multiple unidirectional streams, without blocking the chunks of data in other direction.
S1AP (S1 Application Part) is the signaling service between E-UTRAN and the Evolved Packet Core (EPC) that fulfills the S1 Interface functions such as SAE Bearer management functions, Initial context transfer function, Mobility functions for UE, Paging, Reset functionality, NAS signaling transport function, Error reporting, UE context release function, Status transfer.
MME S11 Interface support
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 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.
The PGW consists of S5/S8 control and data plane stacks to support S5/S8 interface with SGW.
PGW supports S5/S8 interface with Serving Gateway. The integrated control plane stack for the S5/S8 interfaces consists of IP
, UDP
, eGTP-C.
The integrated data plane stack for the S5/S8 interface consists of IP
, UDP
, eGTP-U.
domain, which is traditionally used for phone calls and SMS
.
3GPP specified two solutions for voice:
3GPP specified two solutions for SMS:
CSFB and SMS over SGs are seen as interim solutions, the long term being IMS
.
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.
3GPP
The 3rd Generation Partnership Project is a collaboration between groups of telecommunications associations, known as the Organizational Partners...
's LTE
3GPP Long Term Evolution
3GPP Long Term Evolution, usually referred to as LTE, is a standard for wireless communication of high-speed data for mobile phones and data terminals. It is based on the GSM/EDGE and UMTS/HSPA network technologies, increasing the capacity and speed using new modulation techniques...
wireless communication standard.
SAE is the evolution of the GPRS Core Network
GPRS Core Network
The GPRS core network is the central part of the General Packet Radio Service which allows 2G, 3G and WCDMA mobile networks to transmit IP packets to external networks such as the Internet...
, with some differences:
- simplified architecture
- all-IP Network (AIPN)
- support for higher throughput and lower latency radio access networkRadio access networkA radio access network is part of a mobile Telecommunication system. It implements a radio access technology. Conceptually, it resides between a device such as a Mobile phone, a computer, or any remotely controlled machine and provides connection with its core network...
s (RANs) - support for, and mobility between, multiple heterogeneous access networks, including E-UTRAE-UTRAe-UTRAN or eUTRAN is the air interface of 3GPP's Long Term Evolution upgrade path for mobile networks. It is the abbreviation for evolved UMTS Terrestrial Radio Access Network, also referred to as the 3GPP work item on the Long Term Evolution also known as the Evolved Universal Terrestrial Radio...
(LTE3GPP Long Term Evolution3GPP Long Term Evolution, usually referred to as LTE, is a standard for wireless communication of high-speed data for mobile phones and data terminals. It is based on the GSM/EDGE and UMTS/HSPA network technologies, increasing the capacity and speed using new modulation techniques...
and LTE AdvancedLTE AdvancedLTE Advanced is a preliminary mobile communication standard, formally submitted as a candidate 4G system to ITU-T in late 2009, was approved into ITU, International Telecommunications Union, IMT-Advanced and expected to be finalized by 3GPP in early 2011...
air interface), 3GPP legacy systems (for example GERANGERANGERAN is an abbreviation for GSM EDGE Radio Access Network. The standards for GERAN are maintained by the 3GPP...
or UTRANUtranUtran is a census town in Surat district in the Indian state of Gujarat.-Geography:Utran is located at . It has an average elevation of 12 metres .-Demographics:...
, air interfaces of GPRS and UMTS respectively), but also non-3GPP systems (for example WiMAXWiMAXWiMAX is a communication technology for wirelessly delivering high-speed Internet service to large geographical areas. The 2005 WiMAX revision provided bit rates up to 40 Mbit/s with the 2011 update up to 1 Gbit/s for fixed stations...
or cdma2000CDMA2000CDMA2000 is a family of 3G mobile technology standards, which use CDMA channel access, to send voice, data, and signaling data between mobile phones and cell sites. The set of standards includes: CDMA2000 1X, CDMA2000 EV-DO Rev. 0, CDMA2000 EV-DO Rev. A, and CDMA2000 EV-DO Rev. B...
)
SAE Architecture
The SAE has 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 equivalent of GPRS networks (via the Mobility Management Entity, Serving Gateway and PDN Gateway subcomponents).
The subcomponents of the EPC are:
- MME (Mobility Management Entity): The MME is the key control-node for the LTE access-network. It is responsible for idle mode UE (User Equipment) tracking and paging procedure including retransmissions. It is involved in the bearer activation/deactivation process and is also responsible for choosing the SGW 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 the HSS). The Non Access StratumNon Access StratumNon-access stratum is a functional layer in the UMTS wireless telecom protocol stack between a core network and user equipment.The layer supports signalling and traffic between those two elements. +- – - – - -+ +- – - – - – -+...
(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 NetworkPublic land mobile networkA public land mobile network is a regulatory term in telecommunications. A PLMN is a network that is established and operated by an administration or by a recognized operating agency for the specific purpose of providing land mobile telecommunications services to the public.A PLMN is identified...
(PLMN) and enforces UE roaming restrictions. The MME is the termination point in the network for ciphering/integrity protection for NAS signaling and handles 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 home HSS for roaming UEs.
- SGW (Serving Gateway): The SGW routes and forwards user data packets, while also acting as 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 PGW). For idle state UEs, the SGW terminates the downlink data path and triggers paging when downlink data arrives for the UE. It manages and stores UE contexts, e.g. parameters of the IP bearer service, network internal routing information. It also performs replication of the user traffic in case of lawful interception.
- PGW (PDN Gateway): The PDN Gateway provides connectivity from the UE to external packet data networks by being the point of exit and entry of traffic for the UE. A UE may have simultaneous connectivity with more than one PGW for accessing multiple PDNs. The PGW performs policy enforcement, packet filtering for each user, charging support, lawful interceptionLawful interceptionLawful interception is obtaining communications network data pursuant to lawful authority for the purpose of analysis or evidence. Such data generally consist of signalling or network management information or, in fewer instances, the content of the communications...
and packet screening. Another key role of the PGW is to act as the anchor for mobility between 3GPP and non-3GPP technologies such as WiMAX and 3GPP2 (CDMA 1X and EvDO).
- HSS (Home Subscriber Server): The HSS is a central database that contains user-related and subscription-related information. The functions of the HSS include functionalities such as mobility management, call and session establishment support, user authentication and access authorization. The HSS is based on pre-Rel-4 Home Location Register (HLR) and Authentication Center (AuC).
- ANDSF (Access Network Discovery and Selection Function): 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.
- ePDG (Evolved Packet Data Gateway): The main function of the ePDG is to secure the data transmission with a UE connected to the EPC over an untrusted non-3GPP access. For this purpose, the ePDG acts as a termination node of IPsecIPsecInternet Protocol Security is a protocol suite for securing Internet Protocol communications by authenticating and encrypting each IP packet of a communication session...
tunnels established with the UE.
Non Access Stratum (NAS) protocols
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 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. They also provide the NAS security by integrity protection and ciphering of NAS signaling messages. EPS provides the subscriber with 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.
- EMM (EPS Mobility Management): The EPS Mobility Management (EMM) protocol provides procedures for 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:
- EMM common procedures -- can always be initiated whilst a NAS signalling connection exists. The procedures belonging to this type are initiated by the network. They include GUTI reallocation, Authentication, Security mode control, Identification, EMM information.
- EMM specific procedures -- specific to the UE only. At any time only one UE-initiated EMM specific procedure can run. The procedures belonging to this type are Attach and combined attach, Detach or combined detach, Normal tracking area update and combined tracking area update (S1 mode only), Periodic tracking area update (S1 mode only).
- EMM connection management procedures -- manage the connection of UE with network:
Service request: Initiated by the UE and used to establish a secure connection to the network or to request the resource reservation for sending data, or both.
Paging procedure: Initiated by the network and used to request the establishment of a NAS signalling connection or to prompt the UE to re-attach if necessary as a result of a network failure.
Transport of NAS messages: Initiated by the UE or the network and used to transport NAS messages.
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 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 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.
- ESM (EPS Session Management): 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 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 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 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:
- EPS bearer contexts procedures -- initiated by the network and are used for the manipulation of EPS bearer contexts, including Default EPS bearer context activation, Dedicated EPS bearer context activation, EPS bearer context modification, EPS bearer context deactivation.
- Transaction related procedures -- initiated by the UE to request for resources, i.e. a new PDN connection or dedicated bearer resources, or to release these resources. They include PDN connectivity procedure, PDN disconnect procedure, Bearer resource allocation procedure, Bearer resource modification procedure.
The MME maintains EMM context and EPS bearer context information for UEs in the ECM-IDLE, ECM CONNECTED and EMM-DEREGISTERED states.
EPC protocol stack
- MME (Mobility Management Entity)
The MME protocol stack consists of
- S1-MME stack to support S1-MME interface with eNodeB
- S11 stack to support S11 interface with Serving Gateway
MME supports the S1 interface with eNodeB. The integrated S1 MME interface stack consists of IP
Internet Protocol
The Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...
, SCTP
Stream Control Transmission Protocol
In computer networking, the Stream Control Transmission Protocol is a Transport Layer protocol, serving in a similar role to the popular protocols Transmission Control Protocol and User Datagram Protocol...
, S1AP.
SCTP (Stream Control Transmission Protocol) is a common transport protocol that uses the services of Internet Protocol (IP) to provide a reliable datagram delivery service to the adaptation modules, such as the S1AP. SCTP provides reliable and sequenced delivery on top of the existing IP framework. The main features provided by SCTP are:
Association setup: An association is a connection that is set up between two endpoints for data transfer, much like a TCP connection. A SCTP association can have multiple addresses at each end.
Reliable Data Delivery: Delivers sequenced data in a stream (Elimination of head-of-line blocking): SCTP ensures the sequenced delivery of data with multiple unidirectional streams, without blocking the chunks of data in other direction.
S1AP (S1 Application Part) is the signaling service between E-UTRAN and the Evolved Packet Core (EPC) that fulfills the S1 Interface functions such as SAE Bearer management functions, Initial context transfer function, Mobility functions for UE, Paging, Reset functionality, NAS signaling transport function, Error reporting, UE context release function, Status transfer.
MME S11 Interface support
MME supports S11 interface with Serving Gateway. The integrated S11 interface stack consists of IP
Internet Protocol
The Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...
, UDP
User Datagram Protocol
The User Datagram Protocol is one of the core members of the Internet Protocol Suite, the set of network protocols used for the Internet. With UDP, computer applications can send messages, in this case referred to as datagrams, to other hosts on an Internet Protocol network without requiring...
, eGTP-C.
- SGW (Serving Gateway)
The SGW consists of
- S11 control plane stack to support S11 interface with MME
- S5/S8 control and data plane stacks to support S5/S8 interface with PGW
- S1 data plane stack to support S1 user plane interface with eNodeB
- S4 data plane stack to support S4 user plane interface between RNC of UMTS and SGW of eNodeB
SGW supports S11 interface with MME and S5/S8 interface with PGW. The integrated control plane stack for these interfaces consists of IP
Internet Protocol
The Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...
, UDP
User Datagram Protocol
The User Datagram Protocol is one of the core members of the Internet Protocol Suite, the set of network protocols used for the Internet. With UDP, computer applications can send messages, in this case referred to as datagrams, to other hosts on an Internet Protocol network without requiring...
, eGTP-C.
SGW supports 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
Internet Protocol
The Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...
, UDP
User Datagram Protocol
The User Datagram Protocol is one of the core members of the Internet Protocol Suite, the set of network protocols used for the Internet. With UDP, computer applications can send messages, in this case referred to as datagrams, to other hosts on an Internet Protocol network without requiring...
, eGTP-U.
- PGW (Packet Data Network Gateway)
The PGW consists of S5/S8 control and data plane stacks to support S5/S8 interface with SGW.
PGW supports S5/S8 interface with Serving Gateway. The integrated control plane stack for the S5/S8 interfaces consists of IP
Internet Protocol
The Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...
, UDP
User Datagram Protocol
The User Datagram Protocol is one of the core members of the Internet Protocol Suite, the set of network protocols used for the Internet. With UDP, computer applications can send messages, in this case referred to as datagrams, to other hosts on an Internet Protocol network without requiring...
, eGTP-C.
The integrated data plane stack for the S5/S8 interface consists of IP
Internet Protocol
The Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...
, UDP
User Datagram Protocol
The User Datagram Protocol is one of the core members of the Internet Protocol Suite, the set of network protocols used for the Internet. With UDP, computer applications can send messages, in this case referred to as datagrams, to other hosts on an Internet Protocol network without requiring...
, eGTP-U.
Support of voice services and SMS
The EPC is a packet-only core network. It does not have a circuit-switchedCircuit switching
Circuit switching is a methodology of implementing a telecommunications network in which two network nodes establish a dedicated communications channel through the network before the nodes may communicate. The circuit guarantees the full bandwidth of the channel and remains connected for the...
domain, which is traditionally used for phone calls and SMS
SMS
SMS is a form of text messaging communication on phones and mobile phones. The terms SMS or sms may also refer to:- Computer hardware :...
.
3GPP specified two solutions for voice:
- IMSIP Multimedia SubsystemThe IP Multimedia Subsystem or IP Multimedia Core Network Subsystem is an architectural framework for delivering Internet Protocol multimedia services. It was originally designed by the wireless standards body 3rd Generation Partnership Project , as a part of the vision for evolving mobile...
: A solution for IMSIP Multimedia SubsystemThe IP Multimedia Subsystem or IP Multimedia Core Network Subsystem is an architectural framework for delivering Internet Protocol multimedia services. It was originally designed by the wireless standards body 3rd Generation Partnership Project , as a part of the vision for evolving mobile...
Voice over IPVoice over IPVoice over Internet Protocol is a family of technologies, methodologies, communication protocols, and transmission techniques for the delivery of voice communications and multimedia sessions over Internet Protocol networks, such as the Internet...
was specified in Rel-7. - Circuit-Switched fallback (CSFB): in order to make or receive calls, the UE changes its radio access technology from LTE3GPP Long Term Evolution3GPP Long Term Evolution, usually referred to as LTE, is a standard for wireless communication of high-speed data for mobile phones and data terminals. It is based on the GSM/EDGE and UMTS/HSPA network technologies, increasing the capacity and speed using new modulation techniques...
to a 2G/3G technology that supports circuit-switched services. This feature requires 2G/3G coverage. A new interface (called SGs) between the MME and the MSC is required. This feature was developed in Rel-8.
3GPP specified two solutions for SMS:
- IMSIP Multimedia SubsystemThe IP Multimedia Subsystem or IP Multimedia Core Network Subsystem is an architectural framework for delivering Internet Protocol multimedia services. It was originally designed by the wireless standards body 3rd Generation Partnership Project , as a part of the vision for evolving mobile...
: A solution for SMS over IP was specified in Rel-7. - SMS over SGs: this solution requires the SGs interface introduced during the work on CSFB. SMS are delivered in the Non Access StratumNon Access StratumNon-access stratum is a functional layer in the UMTS wireless telecom protocol stack between a core network and user equipment.The layer supports signalling and traffic between those two elements. +- – - – - -+ +- – - – - – -+...
over LTE. There is no inter-system change for sending or receiving SMS. This feature was specified in Rel-8.
CSFB and SMS over SGs are seen as interim solutions, the long term being IMS
IP Multimedia Subsystem
The IP Multimedia Subsystem or IP Multimedia Core Network Subsystem is an architectural framework for delivering Internet Protocol multimedia services. It was originally designed by the wireless standards body 3rd Generation Partnership Project , as a part of the vision for evolving mobile...
.
Multiple access networks
The UE can connect to the EPC using several access technologies. These access technologies are composed of:- 3GPP accesses: these access technologies are specified by the 3GPP3GPPThe 3rd Generation Partnership Project is a collaboration between groups of telecommunications associations, known as the Organizational Partners...
. They include GPRS, UMTS, EDGEEdge- Aviation :* Leading edge, a line connecting the forward-most points of a wing's profile* Trailing edge, the rear edge of the wing* Zivko Edge 540, an aerobatic aircraft- Mathematics, science and technology :...
, HSPAHigh Speed Packet AccessHigh Speed Packet Access is an amalgamation of two mobile telephony protocols, High Speed Downlink Packet Access and High Speed Uplink Packet Access , that extends and improves the performance of existing WCDMA protocols...
, LTE3GPP Long Term Evolution3GPP Long Term Evolution, usually referred to as LTE, is a standard for wireless communication of high-speed data for mobile phones and data terminals. It is based on the GSM/EDGE and UMTS/HSPA network technologies, increasing the capacity and speed using new modulation techniques...
and LTE AdvancedLTE AdvancedLTE Advanced is a preliminary mobile communication standard, formally submitted as a candidate 4G system to ITU-T in late 2009, was approved into ITU, International Telecommunications Union, IMT-Advanced and expected to be finalized by 3GPP in early 2011...
. - non-3GPP accesses: these access technologies are not specified by the 3GPP3GPPThe 3rd Generation Partnership Project is a collaboration between groups of telecommunications associations, known as the Organizational Partners...
. They include technologies such as cdma2000CDMA2000CDMA2000 is a family of 3G mobile technology standards, which use CDMA channel access, to send voice, data, and signaling data between mobile phones and cell sites. The set of standards includes: CDMA2000 1X, CDMA2000 EV-DO Rev. 0, CDMA2000 EV-DO Rev. A, and CDMA2000 EV-DO Rev. B...
, WiFiWIFIWIFI is a radio station broadcasting a brokered format. Licensed to Florence, New Jersey, USA, the station is currently operated by Florence Broadcasting Partners, LLC.This station was previously owned by Real Life Broadcasting...
or fixed networks. 3GPP specifies two classes of non-3GPP access technologies with different security mechanisms:- trusted accesses, that the network operator consider trustable from a security stand point (for example: a cdma2000CDMA2000CDMA2000 is a family of 3G mobile technology standards, which use CDMA channel access, to send voice, data, and signaling data between mobile phones and cell sites. The set of standards includes: CDMA2000 1X, CDMA2000 EV-DO Rev. 0, CDMA2000 EV-DO Rev. A, and CDMA2000 EV-DO Rev. B...
network). Trusted non-3GPP accesses interface directly with the network. - untrusted accesses, that the network operator doesn't consider trustable from a security stand point (for example, a connection over a public WiFi hotspot). Untrusted non-3GPP accesses are connected to the network via an ePDG, which provide additional security mechanisms (IPsecIPsecInternet Protocol Security is a protocol suite for securing Internet Protocol communications by authenticating and encrypting each IP packet of a communication session...
tunneling).
- trusted accesses, that the network operator consider trustable from a security stand point (for example: a cdma2000
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.
3GPP releases
The 3GPP delivers standards in parallel releases, which compose consistent sets of specifications and features.| Version | Released | Info |
|---|---|---|
| Release 7 | 2007 Q4 | Feasibility study on All-IP Network (AIPN) |
| Release 8 | 2008 Q4 | First release of EPC. SAE specification: high level functions, support of LTE and other 3GPP accesses, support of non-3GPP accesses, inter-system mobility, Single Radio Voice Call Continuity (SRVCC), CS fallback. Earthquake and Tsunami Warning System (ETWS). Support of Home Node B Home Node B A Home Node B, or HNB, is the 3GPP's term for a 3G femtocell.A Node B is an element of a 3G macro Radio Access Network, or RAN. A femtocell performs many of the function of a Node B, but is optimized for deployment in the home.-Standard:... / Home eNode B. |
| Release 9 | 2009 Q4 | LCS control plane for EPS. Support of IMS emergency calls over GPRS and EPS. Enhancements to Home Node B Home Node B A Home Node B, or HNB, is the 3GPP's term for a 3G femtocell.A Node B is an element of a 3G macro Radio Access Network, or RAN. A femtocell performs many of the function of a Node B, but is optimized for deployment in the home.-Standard:... / Home eNode B. Public Warning System (PWS). |
| Release 10 | 2011 Q1 | Network improvements for machine-type communications. Various offload mechanisms (LIPA, SIPTO, IFOM). |
| Release 11 | 2012 Q3 (to be confirmed) | Work in progress (as of September 2011). Further improvements for machine-type communications. Simulation of USSD in IMS. QoS control based on subscriber spending limits. Further improvements to LIPA and SIPTO. Single Radio Video Call Continuity (vSRVCC). Support of interworking with Broadband Forum Broadband Forum The Broadband Forum is a non-profit industry consortium dedicated to developing broadband network specifications. Members include telecommunications networking and service provider companies, broadband device and equipment vendors, consultants and independent testing labs... accesses. |