KPIs for Mobile Services MTSI - Multimedia Telephony Services over IMS Effects of Transmission Performance on Multimedia QoS STQ Mobile represented by K. Adler, J. Gustafsson, G. Heikkilä ETSI 2007. All rights reserved
Presentation Content Introduction Key Performance Areas Control Plane Realtime User Plane Non-realtime User Plane MTSI vs. PoC Summary Multimedia Telephony Services over IMS 2
MTSI Interoperability Concept Today Multimedia Telephony A Voice + SMS + (MMS) Voice B A Voice + Video + Messaging + File sharing + Presence B C D C D Voice Multimedia Telephony Services over IMS 3
MTSI Communication My devices My Contacts Communication Voice Call + + Video Call Conference call Video share Chatting Share a file Multimedia Telephony Services over IMS 4
Add/drop of Media During a Session Users 3 2 1 Media Presence Messaging Voice Video File sharing Multimedia Telephony Services over IMS 5
Key Performance Areas MTSI Control Plane (SIP/SDP) Registration Session setup Session add/drop Session completion MTSI User Plane (realtime RTP/UDP) Speech quality Speech delay Video quality Video delay Real-time text MTSI User Plane (non-realtime MSRP/TCP) Messaging File or media sharing Multimedia Telephony Services over IMS 6
SIP Call Setup and RTP/MSRP Media Flow Home network TAS Visited network SIP HSS SIP S.CSCF SIP I.CSCF SIP I.CSCF SIP SIP P.CSCF P.CSCF SIP RTP or MSRP SIP UE A UE B Multimedia Telephony Services over IMS 7
MTSI Registration Failure Ratio MTSI Registration Time Control Plane KPIs MTSI Session Set-up Failure Ratio MTSI Session Set-up Time Examples on following slides MTSI Session Add Failure Ratio MTSI Session Add Time MTSI Session Remove Failure Ratio MTSI Session Remove Time MTSI Session Completion Failure Ratio Multimedia Telephony Services over IMS 8
MTSI Registration Time Note that first response is always an authentication failure MTSI Registration Time Multimedia Telephony Services over IMS 9
User decides to add video User modifies session MTSI Session Add Time IMS Client Initate session signal Terminal IMS Core MTAS SIP INVITE SIP INVITE SIP INVITE to terminating network MTSI Add Time SIP 183 Session Progress from terminating network SIP 183 Session Progress SIP 183 Session Progress Add time can differ depending SIP PRACK SIP PRACK to Resource SIP PRACK on added service, due terminating to network Reservation SIP 200 OK (PRACK) different SIP 200 OK (PRACK) need of radio SIP 200 OK (PRACK) SIP UPDATE resource SIP UPDATE to SIP UPDATE reservations terminating network Callee alerted notification Session changed notification Alerted signal Session set-up signal SIP 200 OK (UPDATE) SIP 180 Ringing SIP 200 OK (UPDATE) SIP 180 Ringing SIP 200 OK (UPDATE) SIP 180 Ringing from terminating network SIP 200 OK (INVITE) SIP 200 OK (INVITE) SIP 200 OK (INVITE) Note that auto-answer is always used for drive-testing measurements Multimedia Telephony Services over IMS 10
MTSI Speech Quality MTSI Speech Path Delay Realtime User Plane MTSI Video Quality MTSI Video Path Delay Discussion on following slides MTSI Audio/Video Synchronization MTSI Real-Time Text Failure Ratio MTSI Real-Time Text Delivery Time Multimedia Telephony Services over IMS 11
MTSI Speech Quality MTSI speech requires jitter buffer in terminal Speech is very sensitive to exact playout time The buffer handles variation in arrival time for speech frames Depth of jitter buffer is a compromise Small buffer means low delay Large buffer handles jitter variations better Adaptive jitter buffer often used Buffer depth changes when radio environment changes Uses speech time-scaling to shorten or lengthen output speech during buffer depth adaptations Objective speech quality measurements currently difficult ITU-T P.862 (PESQ) cannot handle time-scaling Ongoing ITU-T P.OLQA standardization promises to handle this Multimedia Telephony Services over IMS 12
MTSI Real-Time Text Delivery Time Not an ordinary chat service Chat services (e.g. MSN) typically transfers the whole line of text after the user press Enter Not a messaging service Messaging services (e.g. SMS, MMS) typically are sessionless Real-time text characteristics The text transfer is done during an ongoing session Every character (or erasing of a character) is shown to the other party Instant feedback, more like a real-life conversation than a chat Relevant measurements Transfer delay and transfer failure Delay requirements are in the order of 500 ms for a high-fidelity realtime text feeling Multimedia Telephony Services over IMS 13
Non-realtime User Plane MTSI Messaging Failure Ratio MTSI Messaging Delivery Time MTSI File/Media Sharing Failure Ratio MTSI File/Media Sharing Mean Data Rate Example on next slide Multimedia Telephony Services over IMS 14
MTSI Messaging Delivery Time MTSI messaging characteristics Message exchange are done within the context of a session Different media can be sent; text, speech, video etc. Can be seen as MMS within a session, but without the size restrictions of an MMS IMS Client Terminal IMS Core MTAS User starts the messaging application Initate messaging session signal SIP INVITE SIP 200 OK (INVITE) SIP INVITE Delivery time depends on message size SIP 200 OK (INVITE) SIP INVITE to terminating network SIP 200 OK (INVITE) from terminating network User sends message Send message signal MSRP SEND TCP Connection Set-up MSRP SEND MSRP SEND Message delivered notification Message delivered signal MSRP 200 OK MSRP 200 OK MSRP 200 OK MTSI Messaging Delivery Time Multimedia Telephony Services over IMS 15
MTSI vs. PoC Red = PoC combination parameters green = PoC mode parameters MTSI Registration Failure Ratio MTSI Registration Time MTSI Session Set-up Failure Ratio MTSI Session Set-up Time MTSI Session Add Failure Ratio MTSI Session Add Time MTSI Session Remove Failure Ratio MTSI Session Remove Time MTSI speech and PoC share some common characteristics, but the different modes for PoC requires more KPIs MTSI Session Completion Failure Ratio MTSI Session Completion Time MTSI Deregistration Failure Ratio MTSI Deregistration Time MTSI Speech Path Delay MTSI Speech Quality PoC Registration Failure Ratio PoC Registration Time PoC Publish Failure Ratio PoC Publish Time PoC Registration Failure Ratio (long) PoC Registration Time (long) PoC Session Initiation Failure Ratio (on demand) PoC Session Initiation Time (on demand) PoC Session Media Par. Neg. Failure Ratio (pre) PoC Session Media Par. Neg. Time (pre) PoC Session Initiation Failure Ratio (pre established) PoC Session Initiation Time (pre established) PoC Session Setup Failure Ratio (on demand) PoC Session Setup Failure Ratio (pre established) PoC Session Setup Time PoC Push to Speak Failure Ratio PoC Push to Speak Time PoC Session Leaving Failure Ratio (on demand) PoC Session Leaving Time (on demand) PoC Session Leaving Failure Ratio (pre established) PoC Session Leaving Time (pre established) PoC Deregistration Failure Ratio PoC Deregistration Time PoC Busy Floor Response Failure Ratio PoC Busy Floor Response Time PoC Talk Burst Request Failure Ratio PoC Talk Burst Request Time PoC Talk Burst Cut off Ratio PoC Talk Burst Packet Drop Ratio PoC Voice Transmission Delay (first) PoC Voice Transmission Delay (others) PoC Speech Quality Multimedia Telephony Services over IMS 16
Summary IMS-based services promises an enhanced end-user experience Allows easy combination of different media types within one session Achieving good end-user quality is vital for success Important to use relevant KPI:s for the MTSI services ETSI STQ Mobile is well prepared with ongoing standardization work for MTSI services ITU-T is also currently standardizing new algorithms for objective speech and video quality assessment, suitable for MTSI services Thank you for your attention! Multimedia Telephony Services over IMS 17