MTD-05c
Question: Q.13 interim Ad-hoc meeting Nov. 17, 1999
*SOURCE: Motorola (Contribution)
TITLE: Integrating 3GPP's option-1 architecture into the H.323 wireless IP
mobility system and a full migration from GPRS to a Multimedia IP
network proposal
SUBJECT: Enhancements to ITU-T Recommendation H.323 to support User,
Terminal and Service Mobility
The present contribution outlines the system architecture, and the reference configurations which
are necessary for:
? The delivery of telephone calls which originate in an GPRS and/or wireless IP network and
are delivered to Switched Circuit Networks (SCN), such as Public Switched Telephone
Network (PSTN), Integrated Services Digital Networks (ISDN) and Global System for
Mobile communication (GSM) networks (Scenario 1).
? The delivery of telephone calls which originate in SCNs and are delivered in an GPRS
and/or wireless IP network (Scenario 2).
? The delivery of telephone calls which originate in SCNs, routed through a GPRS and/or
wireless IP network and finally delivered to an SCN (Scenario 3).
? The delivery of telephone calls which originate in GPRS and/or IP networks, routed through
an SCN and finally are delivered to an IP network (Scenario 4).
These four call scenarios part of the basic requirements. The present contribution is applicable to
equipment performing the roles of a mobile terminal, fixed PC terminal, Gateway GPRS Support
Node (GGSN), Serving GPRS Support Node (SGSN), Signalling Gateway, Gatekeeper and
Gateway.
Table of Contents:
Definitions ............................................................................................................................................... 2 References ............................................................................................................................................... 3 Abbreviations ................................................................................................................................... 3 Introduction ............................................................................................................................................. 4 Discussion ............................................................................................................................................... 4 Interworking ...................................................................................................................................... 4 Mobility management ...................................................................................................................... 4
Roaming ............................................................................................................................................ 4 Handover ........................................................................................................................................... 4 Reference Architectures ....................................................................................................................... 5 Conclusion............................................................................................................................................... 9
* Contact Person:
Edgar Martinez Tel: 1-847-632-5278 1501 W. Shure Drive. Fax: 1-847-632-6999 Arlington Heights. IL USA email: martinze@cig.mot.com
Definitions
For the purposes of the present contribution, the following terms and definitions apply:
Gatekeeper: Entity on the IP network which provides address translation and controls access to
the network for terminals and gateways. The gatekeeper may also provide other services to
terminals and gateways, such as bandwidth management and gateway location.
Gateway: A gateway is an endpoint on a network which provides for real-time, two-way
communication between terminals on an IP based network and other terminals on switched circuit
network.
Media Gateway: Provides the media mapping and/or transcoding functions.
Media Gateway Controller: Controls the Media Gateways.
Telephone call: Two-way speech communication between two users by means of terminals connected via network infrastructure.
Signalling Gateway: Provides the signalling mediation function between the IP domain and the SCN domain.
Terminal: An H.323 terminal other than a gateway or a multipoint control unit.
existing service: services supported in Release 99 and earlier releases for both GSM and UMTS.
All IP core network: core network of release 2000 that uses IP for transport of all user data and signalling.
ERAN is defined as an evolved GSM BSS supporting EDGE modulation schemes on a 200kHz
basis and real time packet services.
Public Land Mobile Network: is established and operated by an administration or Recognised
Private Operating Agency (RPOA) for the specific purpose of providing land mobile
telecommunications service services to the public. A PLMN may be regarded as an extension of
a network (e.g. ISDN); it is a collection of MSCs areas within a common numbering plan (e.g.
same National Destination Code) and a common routing plan. The MSCs are the functional
interfaces between the fixed networks and a PLMN for call set-up. Functionally the PLMNs may
be regarded as independent telecommunications entities even though different PLMNs may be
interconnected through the ISDN/PSTN and PDNs for forwarding of calls or network information.
A similar type of interconnection may exist for the interaction between the MSCs of one PLMN.
Serving GPRS Support Node: The location register function in the SGSN stores subscription
information and location information for Packet Switched (PS) services for each subscriber
registered in the SGSN. The SGSN is needed only in a PLMN which supports GPRS.
GPRS Support Nodes: The UMTS PS-services support nodes, Gateway GSN (GGSN) and Serving GSN (SGSN) constitutes the interface between the radio system and the fixed networks
for packet switched services. The GSN performs all necessary functions in order to handle the
packet transmission to and from the mobile stations.
Equipment Identity Register: The Equipment Identity Register (EIR) in the GSM system is the
logical entity which is responsible for storing in the network the International Mobile Equipment
Identities (IMEIs), used in the GSM system. The equipment is classified as "white listed", "grey
listed", "black listed" or it may be unknown as specified in TS 22.016 and TS 29.002.
References
[1] DTR/TIPHON-07001 Analysis of existing roaming techniques applicable to TIPHON
mobility
[2] DTR/TIPHON-07002 Investigation of synergies and common requirements between
TIPHON networks and wireless systems as they are currently being developed by other
bodies.
[3] DTS/TIPHON-07003 Mobility and Access to Wireless Systems; Extensions to
Requirements, Architecture and Protocols.
[4] DTS/TIPHON-02003 v0.3.0 Network architecture and reference configurations; Phase III:
Scenario 1 + Scenario 2 + Scenario 3 + Scenario 4
[5] ITU-T Recommendation H.323 (1998): "Packet-based multimedia communication".
[6] 3rd Generation Partnership Project; Technical Specification Group Services and
Systems Aspects; Architecture for an All IP network (3G TR 23.922 version 1.0.0)
[7] 3rd Generation Partnership Project; Technical Specification Group Services and
Systems Aspects; Network architecture (3G TS 23.002 version 3.1.0)
Abbreviations
For the purposes of the present document, the following abbreviations apply: CAP Capabilities Application Part
CN Core Network
CSCF Call State Control Function
EDGE Enhanced Data for GSM
FFS For Further Study
GGSN Gateway GPRS Support Node
GK GateKeeper
GPRS General Packet Radio Service
GSM Global System for Mobile communications GW Gateway
HSS Home Subscriber Server
IP Internet Protocol
MCU Media Control Unit
MG Media Gateway
MGC Media Gateway Controller
MGCF Media Gateway Controller Function
MGW Media Gateway
MRF Media Resource Function
MT Mobile Terminated/Terminal
PLNM Public Land Mobile Network
PS Packet Switched
PSTN Public Switched Telephone Network
R00 Release 2000
R99 Release 1999
R-SGW Roaming Signalling Gateway
SCP Service Control Point
SG Signalling Gateway
SGSN Serving GPRS Support Node
TE Terminal Equipment
T-SGW Transport Signalling Gateway
UTRAN UMTS Terrestrial Radio Access Network VoIP Voice over IP
Introduction
A recently approved 3GPP feasibility report TR 23.xyz v.0.1. was considered for this contribution ndespecially section 5 which illustrated two architectural options, the 2 option seems to be closest
to a IP type of architecture. This contribution tries to address an alternated option to 3GPP's
option 2 of IP architecture.
Discussion
rdThe aim of the all IP architecture is to allow operators to deploy IP technology to deliver 3
Generation services, that is an architecture based on packet technologies and IP telephony for simultaneous real time and non real time services. This architecture should be based on an evolution from Release 99 specifications and should be compatible with IMT-2000, providing global terminal mobility (roaming) [TS 22.101 version 3.6.0: Service Principles].
The IP network should provide wireless mobility access based on ERAN and UTRAN with a common core network, based an evolution of GPRS, for both. In this context, an E-GPRS radio access network is a 200kHz GSM based network supporting EDGE and evolved to support real time packet services. Although EDGE is not within the scope of 3GPP, there are requirements for the core network of the all IP architecture, to be common to both access technologies.
The characteristics of this network are:
? Based on an evolution of GPRS
? Common network elements for multiple access types including UTRAN and ERAN ? Packet transport using IP protocols
? IP Client enabled terminals
? Support for voice, data, real time multimedia, and services with the same network elements.
The report also covers the support of CS services on IP technologies. The benefits of this approach include:
? Ability to offer seamless services, through the use of IP, regardless of means of access (e.g.
common features used by subscribers whether accessing via conventional land telephony,
cable, wireless, HIPERLAN 2 etc.)
? Synergy with generic IP developments and reduced cost of service
? Efficient solution for simultaneous multi-media services including voice, data, and advanced
real time services.
? Higher level of control of services
? Integrated, and cost reduced OA&M through IP
? Take advantage of Internet applications by supporting terminals which are IP clients. ? Cost reduction through packet transport
Interworking
The All-IP core network shall support interworking to external IP and non-IP networks (e.g. circuit-switched networks (PSTN, ISDN, GSM PLMN, UMTS PLMN,...).
Mobility management
The All-IP core network shall provide streamlining and CN operated hand-over procedures for UMTS.
Roaming
The standard shall enable the All-IP core network to support roaming with 2G GSM/GPRS networks and R99 UMTS networks.
Handover
The support of handover between release 98, release 99 and release 2000 network technologies is essential in maintaining adequate network coverage.
Reference Architectures
[6]The original 3GPP reference architecture provided two options.
The GPRS network part has the GSNs which provide the mobility management and the PDP context activation services to the mobile terminal as they do in the R99 GPRS PS domain network. The HLR functionality for the GPRS network is provided by the Home Subscriber Server, (HSS).
The Call Control part of the architecture is the most critical functionality. The CSCF, MGCF, R-SGW, MGW, T-SGW and the MRF comprise the Call Control and signalling functionality to deliver the real-time mobile/wireless services. The CSCF is similar to the H.323 GateKeeper or a SIP Server. The architecture has been intentionally kept generic and is not based on a specific call control mechanisms such as H.323 or SIP. Such a choice is for further study.
The user profiles are maintained in the HSS. The signalling to the multimedia IP network is interface solely via the CSCF while the bearer is interfaced directly with the GGSN. The MRF interfaces with all bearer components for bearer media and with the CSCF for signaling. The MRF provides for media mixing, multiplexing, other processing and generation functions.
The interconnectivity to external networks such as PLMN, other PDNs, other multimedia VOIP networks and 2G Legacy networks (GSM or TDMA) is supported by the GGSN, MGCF, MGW, R-SGW and T-SGW functional elements. Other PLMNs are interfaced for both bearer and signalling via their respective GPRS components. The CSCF is a new component which also participates in this signalling. The signalling to legacy mobile networks is interfaced via the R-SGW, CSCF, MGCF, T-SGW and HSS, while the bearer is interfaced to and from the legacy PSTN network via an MGW. Legacy landline circuit switch signalling is interfaced via the CSCF, MGCF and T-SGW while the bearer is interfaced to and from the legacy PSTN network via an MGW.
Option 1: has been developed with the goal of allowing operators to deploy an all IP based rdarchitecture to deliver 3 Generation wireless/mobile services. This architecture is based on
packet technologies and IP telephony for simultaneous real time and non real time services. The
reference architecture shown figure 1 is take the from 3GPP technical requirements. See 3G TR [6]23.922 version 1.0.0 for full details of option 1.
Applications &Other PLMNHSSServices
GGSNSCPCxEIRGp
CAPLegacyGfMobileCSCFR-SGWNetworkMsUTRANMrTEMTSGSNIuRUuMgMRF
GnERANMTTEIu-ps Gi
RUmGiT-SGWMGCFPSTN/Legacy/ExternalMc
Signalling InterfaceGGSNMGWGiGiSignallingand
Data Interface
Multimedia IP Network
Ref: 3G TR 23.922 version 1.0.0 (1999-10)
Reference Architecture Option 1.
For simplicity, only the 3GPP interfaces relevant to H.323 interfaces are shown for discussion.
Alternate Proposal for an all IP option for 3GPP R'00:. The purpose the all IP proposal is also to allow support of release 99 CS domain terminals. In addition it will also support the IP based services of option 1.
Applications &Other PLMNServices
GGSNSCPHSSEIRCxCAPGfGpLegacyR-SGWCSCFMobileSGSN( GK )( SG1 )Network( GK )MsSGSNGn
Iu-iH.323MgTerminalUTRANTEMTT-SGWMrMGCFRIu-ps Uu( SG( MGC )MRF2 )PSTN/GnGi( MCU )McLegacy/External
Gi
MGWGGSN
( MG )GiGi
ERANMTTE
Signalling InterfaceRUmMultimedia Signalling/Data/VoIPIP Network GPRS Signalling & Data
H.323 Elements ( X )Sigtran ( SGx )Alternate proposal for 3GPP R?0 Option 2.
For details on the G's, Iu's, Cx and M's interfaces see (3G TR 23.922 version 1.0.0).
Full migration from GPRS to Multimedia IP network:. Based on the proposed diagram for an Alternate all IP option for 3GPP R'00 the migration to a full IP solution can be realised if the MG
could support the Gn interface. It also becomes obvious, that if the ERAN Iu could support pure
data over IP, it could be also connected to the IP Multimedia Network directly.
Applications &Legacy PLMNServicesWireless & FixedGGSNSCPHSSMultimediaEIRIP NetworkCxCAPGpGf
LegacyR-SGWMobileSGSNCSCFSGSN( SG1 )Network( GK )( GK )MsGn Iu-iIu-iH.323MgTerminalERANUTRAN
MrGiT-SGWMGCF
MRF2 )( SGPSTN/Gi( MGC )Gn( MCU )Legacy/ExternalMc
Gi
GGSN + MGW( MG )
Signalling Interface
Signalling/Data/VoIPGPRS Signalling & Data
H.323 Elements ( X )Sigtran ( SGx )Full GPRS Migration to the IP Multimedia Network.
Not shown in diagram for simplicity, the ERAN and UTRAN interfaces, Uu and Um will still be
supposed.
Proposed Universal IP Network solution
Proposal - Universal H.323 Interoperability with PSTN, PLMN and IP Wireless Mobility
Scope ofIP Wireless MobilityBES
LNPHLFVLF
H.323H.323H.323GatekeeperMCUTerminal
Packet Based Network
(Note)
H.323GGSNSS7BTS orH.323GatewayGatewayIP-RANGateway
SCPHLR
GPRS DataSS7CS Voice/DataCS Voice/DataGpNon-H.323 H.323 MobileNetworkTerminalMobile Terminal
LegacyCS Voice/DataGPRSPSTNMSC
MobileTerminalRANBSC
TerminalAnalogBRIPBXPhones
Non-H.323 Mobile Terminal
NOTE ?The IP-RAN (UTRAN and or ERAN) may support one or more types of Non-H.323 Mobile Terminals
Conclusion
The H.323 mobility group should also consider the interworking of the GPRS network and provide
a GPRS migration path to a full IP network solution. Such as the work in H.323 is providing an
interworking and migration path for the PSTN to a full IP network solution. In addition the H.323
mobility group could include the two options the Alternate Proposal for an all IP option for 3GPP
R'00 (interim) and the full migration from GPRS to Multimedia IP network into H.323 Annex-H
interworking sections. Further details can be discussed within the H.323 mobility group.