volte ims network architecture
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The document provides an overview of Voice over LTE (VoLTE), detailing its architecture, components, and benefits for users. It describes the interaction between various network elements, such as the IMS, LTE core, SIP servers, and user equipment, emphasizing the importance of Quality of Service (QoS) in prioritizing VoLTE traffic. Additionally, it notes that existing user SIMs can support VoLTE without mandatory swaps to specific versions.
volte ims network architecture
- 2. VoLTE • VoLTE Fundamentals • Handset Requirements • LTE Network Support • IMS Architecture • CS Network Support • QCI & Prioritization of VoLTE Traffic over Radio VoLTE Evolution & Architecture Disclaimer : Views expressed in this blog or Video are strictly mine and not of my employers or Equipment Manufacturers http://TelecomTutorial.info
- 3. LTE or PSTN What is VoLTE LTE IMS enables a packet-based network to provide multiple services on single Control/Service Layers via different access network. IMS IP Network PSTN or LTE IP Network Calling Party Called Party Originating Network Terminating Network • Access agnostic • Services independent • Open architecture • Multi-device • Vendor independent Key Drivers to IMS http://TelecomTutorial.info
- 4. VoLTE Building blocks VoLTE : Voice over LTE • Voice calls over a 4G LTE network • LTE Packet Network used for carrying voice payload over all IP Network SIP Enabled User Equipment Handset LTE Network Radio , Core IMS Core ( SIP Network ) • HD Voice • Fast Call connection (0.25s) VoLTE Benefits to users Voice Core PSTN SIP SERVER IP Nw http://TelecomTutorial.info
- 5. VoLTE Network - Building blocks SIP Enabled Smartphone or Handset LTE Network Radio , Core IMS Core (SIP) Voice Core PSTN • Radio EnodeB • LTE Core MME , SGW , PGW HSS DNS PCRF • SIM Card (ISIM) IMPI IMPU • Handset SIP-UA • Control Plane MSS MSC • User Plane MGW • SIP Servers P-CSCF I-CSCF S-CSCF • Other IMS Core TAS BGw MRF 1 2 3 4 http://TelecomTutorial.info
- 6. VoLTE Handset Components (User Equipment) Universal Integrated Circuit (UICC) IMPI • Private Entity • Global identity allocated by home network IMPU • Public Identity • Like a telephone No. SIP URI , Ex : tel :- +919810602654 • SIP User Agent (SIP-UA) 1. Resides in the UE 2. Transmit & receive SIP Messages 3. Provides telephony functionality 4. Can act as • User Agent Client (UAC) : send SIP request • User Agent Server (UAS) : As a server to receive requests and send response SIP User Agent (SIP-UA) 1 SIM USIM ISIM GSM LTE VoLTE http://TelecomTutorial.info
- 7. VoLTE Building blocks SIP Enabled Smartphone or Handset LTE Network Radio , Core IMS Core (SIP) Voice Core PSTN Universal Integrated Circuit (UICC) IMPI IMPU SIP User Agent (SIP- UA) 1 2 3 4 http://TelecomTutorial.info
- 8. LTE Architecture enB S-GW P-GW MME HSS LTE-UU S1-U S5 S11 S6a OCS PCRF Gy Gx InternetSGi Control Plane User Plane Control Plane P-GW IMSENodeB User Plane2 http://TelecomTutorial.info
- 9. VoLTE Building blocks User Equipment Handset LTE Network Radio , Core IMS Core (SIP) Voice Core PSTN Universal Integrated Circuit (UICC) SIP User Agent (SIP- UA) 1 2 3 4 http://TelecomTutorial.info
- 10. IMS VoLTE Architecture & Specs IMS SPECS 3GPP 23.228 • GSMA FCM.01 • GSMA IR.92 3 http://TelecomTutorial.info
- 11. enB S-GW P-GW MME HSS S5 S11 S6a PCRF Gx Internet SGi LTE to VoLTE Journey eNB ( EnodeB ) MME ( Mobility Management Entity ) SGW ( Serving Gateway ) HSS ( Home Subscriber Server ) PCRF ( Policy charging rules function ) PGW ( Packet Gateway ) http://TelecomTutorial.info
- 12. Here is IMS IMS IP Telephony IMS ( IP Multimedia Subsystem ) enB S-GW P-GW MME HSS S5 S11 S6a PCRF Gx Internet SGi http://TelecomTutorial.info
- 13. SIP Server enB S-GW P-GW MME HSS S5 S11 S6a PCRF Gx Internet SGi SIP Service • Session set-up, session tear-down, session control and routing functions. • Records for billing purposes for all sessions • SIP registrar for VoLTE UEs IMS ( IP Multimedia Subsystem ) Media Gateway Other IMS Networks / PSTN SIP Server http://TelecomTutorial.info
- 14. Media Gateway enB S-GW P-GW MME HSS S5 S11 S6a PCRF Gx Internet SGi IMS ( IP Multimedia Subsystem ) Media Gateway • Responsible for the control/media plane interworking at the network • Interconnect point to circuit-switched networks. • Transcoding of the media plane. • Interconnect to other IMS Networks Media Gateway Other IMS Networks / PSTN SIP Server http://TelecomTutorial.info
- 15. Role of IPCAN Internet Access Network Media Gateway Other IMS Networks / PSTNLTE SIP Server Or Wifi Or DSL , Cable IP Connectivity Access Network (IP-CAN) http://TelecomTutorial.info
- 16. The Proxy SIP Proxy • First Point of Entry point to IMS Network • Typically Belongs to VPLMN • Function : Integrity of SIP Messages , Ensures the security , Authenticates & identity of the UE • Find out Home SIP Server & Routes Traffic to same SIP Server S-CSCF LTE SIP Proxy Proxy CSCF Or P-CSCF Media Gateway Other IMS Networks / PSTN http://TelecomTutorial.info
- 17. The Interrogator Interrogator I-CSCF SIP Server S-CSCF HSS LTE Media Gateway Other IMS Networks / PSTN Interrogator • Belongs to Home Network • Interrogates the HSS to determine SIP Server • During Registration • During MT Call routing SIP Proxy P-CSCF http://TelecomTutorial.info
- 18. HSS (Home Subscriber Server) HSS ( Home Subscriber Server ) Interrogator I-CSCF SIP Server S-CSCF LTE Media Gateway Other IMS Networks / PSTN HSS ( Home Subscriber Server ) • Stores Profile of User • Equivalent to HLR of Circuit Domain SIP Proxy P-CSCF HSS http://TelecomTutorial.info
- 19. The Telephony App Server (TAS) LTE Telephony App Server (TAS) HSS Media Gateway Other IMS Networks / PSTN SIP Proxy P-CSCF Interrogator I-CSCF SIP Server S-CSCF Telephony App Server • Types of App Servers : Telephony Service , Video Service , Multimedia Service • TAS : Telephony Brain to IMS & Equivalent to MSC • Provides : Call waiting, hold, forwarding, transfer , blocking services, Malicious Caller Identification , Lawful interception , Announcements, , Conference http://TelecomTutorial.info
- 20. Media Control Media Gateway Other IMS Networks / PSTN LTE Media Control SIP Proxy P-CSCF Interrogator I-CSCF SIP Server S-CSCF Media Control • Control for media channels • Performs Call Related Signaling for calls with PSTN ( ISUP ) • Performs protocol conversion between ISUP and the IM subsystem protocols TASHSS http://TelecomTutorial.info
- 21. Media Gateway Media Gateway Other IMS Networks / PSTN SIP Proxy P-CSCF Interrogator I-CSCF SIP Server S-CSCF LTE Media Control Media Gateway • Voice Payload handling • Interface between IP / PSTN Network • RTP to PCM & Vice versa conversion • Codec Handling • Echo cancellation HSS TAS http://TelecomTutorial.info
- 22. ( IBCF & TrGW ) , ( MGCF & IMS-MGW ) IMS Gateway Other IMS Networks LTE SIP/IMS Control SIP Proxy P-CSCF Interrogator I-CSCF SIP Server S-CSCF PSTN Gateway PSTN Control Other PSTN Networks TrGW IBCF IMS-MGW MGCF HSS TAS All Media Entities • IBCF (Interconnection Border Control Functions) • TrGW (Transition Gateway) ============================================= • MGCF (Media Gateway Control Function) • IMS-MGw (IP Multimedia-Media Gateway Function) http://TelecomTutorial.info
- 23. ATCF & ATGW SIP Proxy P-CSCF Interrogator I-CSCF SIP Server S-CSCF LTE HSS TASMedia Gateway Access Control ATCF ATGW All Media Entities • ATCF (Access Transfer Control Function) • ATGW (Access Transfer Gateway) Other IMS Networks Other PSTN Networks TrGW IBCF IMS-MGW MGCF http://TelecomTutorial.info
- 24. All Media Entities TrGW Other IMS Networks LTE IBCF SIP Proxy P-CSCF Interrogator I-CSCF SIP Server S-CSCF ATGW ATCF IMS-MGW MGCF Other PSTN Networks All Media Entities • ATCF (Access Transfer Control Function) • ATGW (Access Transfer Gateway) • IBCF (Interconnection Border Control Functions) • TrGW (Transition Gateway) • MGCF (Media Gateway Control Function) • IM-MGw (IP Multimedia-Media Gateway Function) HSS TAS http://TelecomTutorial.info
- 25. PCRF (Policy and Charging Rule Function) PCRF TrGW Other IMS Networks LTE TASHSS IBCF SIP Proxy P-CSCF Interrogator I-CSCF SIP Server S-CSCF IMS-MGW MGCF Other PSTN Networks ATGW ATCF PCRF (Policy and Charging Rule Function) • Apply Policy to PDN or IPCAN Session - Provides priority of Bearers used for Making VoLTE calls & SIP Signaling ( QCI – 1 for Voice , QCI – 5 for SIP ) • Helps Voice call to pass thru even in case of Radio Congestion • Act as Anchoring point between PCSCF & PGW over Gm Protocol reference Point Gx Rx Gm http://TelecomTutorial.info
- 26. MRF ( Media Resource Function ) TrGW Other IMS Networks LTE TASHSS IBCF SIP Proxy P-CSCF Interrogator I-CSCF SIP Server S-CSCF IMS-MGW MGCF Other PSTN Networks PCRF MRF ATGW ATCF MRF ( Media resource function ) • Deals with Call conferencing & things associated with RTP Mixing such as transcoding, multiparty conferencing, network announcements/tones, etc. • It is also used for Announcement & Media related functionalities http://TelecomTutorial.info
- 27. BGCF .. B Number routing Table TrGW Other IMS Networks LTE TASHSS IBCF SIP Proxy P-CSCF Interrogator I-CSCF SIP Server S-CSCF IMS-MGW MGCF Other PSTN Networks PCRF MRF ATGW ATCF BGCFBGCF ( Breakout Gateway Control Function ) • BGCF does routing the call to destination Network • Equivalent to Routing Table in Network , Similar to B Table of MSC http://TelecomTutorial.info
- 28. Complete VoLTE IMS Picture Sessionand ControlLayer App& Services Layer Transport Layer TrGW Other IMS Networks LTE TASHSS IBCF SIP Proxy P-CSCF SIP Interrogator I-CSCF SIP Server S-CSCF IMS-MGW MGCF Other PSTN Networks PCRF MRFATGW ATCF BGCF http://TelecomTutorial.info
- 29. Practical deployment TrGW TASHSS IBCF SIP Proxy P-CSCF SIP Interrogator I-CSCF SIP Server S-CSCF IMS-MGW MGCF MRF ATGW ATCF BGCF LTE PCRF 1 2 3 4 Cloud IMS Hardware SBC Gateway Cloud TAS Cloud MRF External External External External BONUS TIP http://TelecomTutorial.info
- 30. User Equipment Handset LTE Network Radio , Core IMS Core (SIP) Voice Core PSTN Universal Integrated Circuit (UICC) SIP User Agent (SIP- UA) The Big Picture .. 1 2 3 4 TrGW IMS-MGW http://TelecomTutorial.info
- 31. What if LTE Radio is Congested ?? Priority QCI Resource Type Packet Delay Budget Packet Error Loss Rate Example Services 1 5 non-GBR 100ms 10−6 Volte , IMS Signaling 2 1 Guaranteed Bit Rate (GBR) 100ms 10−2 Volte , Conversational Voice 3 3 50ms 10−3 Real Time Gaming, V2X messages 4 2 150ms 10−3 Volte , Conversational Video (Live Streaming) 5 4 300ms 10−6 Non-Conversational Video (Buffered Streaming) 6 6 non-GBR Best Effort 300ms 10−6 Internet Services , Video (Buffered Streaming) TCP-Based (for example, www, email, chat, ftp, p2p and the like) 7 7 100ms 10−3 8 8 300ms 10−6 9 9 300ms 10−6 http://TelecomTutorial.info
- 32. Changes in Core Network to support VoLTE • Default & dedicated Bearer Enable • IMS APN IP Pool • PGW - SBC / PCSCF Reachability • Disable Gy for IMS Packet Core SGW / PGW • Sv Link – SRVCC • IMS APN SGW / PGW Selection • Paging Policy - VoLTE Calls • QCI – 1,5 Testing & Validation Packet Core MME • Sv Link – SRVCC • IMS & MGW – IP Reachability • Break in & Break out Calls Config • Common Codec between MSS & IMS Voice Core MSS / MSC http://TelecomTutorial.info
- 33. I don’t have I-SIM in my Network ? Do existing 3G or LTE customer using USIM need to go for SIM Swap for availing VoLTE Services ? BONUS TIP USIM itself can be used to Avail VoLTE Services , Deriving the IMPU and IMPI for authentication can be done by VoLTE stack/client residing on the UE ( ISIM is not Mandatory ) IMPI :- <IMSI>@ims.mnc<3-digit MNC>.mcc<3-digit MCC>.3gppnetwork.org IMPU :- <MSISDN>@ims.mnc<3-digit MNC>.mcc<3-digit MCC>.3gppnetwork.org Derived Derived http://TelecomTutorial.info
- 34. Thanks VISIT MY WEBSITE http://telecomtutorial.info Vikas Shokeen Free Download – Video 1080p (MP4) Free Download – Presentation (PDF) [email protected] FOR http://TelecomTutorial.info