Part 1 Last, but not least Last mile

Transcription

1 FTTH, Access and Triple-Play Testing Urbino 2011 Alfonso Domesi Business Development Manager Access BU rev.1.0, February 2011 Part 1 Last, but not least Last mile 1

2 Once upon a time Proprietary and Confidential 3 Copper was first choice BASIC COPPER PAIR TERMINOLOGY Tip & Ring / A & B Ground / Earth CO Battery Wire Gauges (0.3, 0.4, 0.5, 0.6 mm) Wire Pair (or copper pair) Ring Tip 26 AWG 24 AWG 22 AWG 48-52VDC - + RING TIP 19 AWG Proprietary and Confidential 4 2

3 Loop Plant: any thing is possible Proprietary and Confidential 5 Loop Plant: any thing is possible Proprietary and Confidential 6 3

4 Switch on the light Proprietary and Confidential 7 Fiber expensive alternative (?) FIBER IS MADE OF DIELECTRIC MATERIAL, CONSISTING OF CORE AND CLADDING, THAT ALLOWS TOTAL INTERNAL REFLECTION OF LIGHT FOR PROPAGATION. Cladding Coating IOR n I IOR n R Core 8mm 125 mm 250mm Proprietary and Confidential 8 4

5 Fiber Plant: any thing is possible Proprietary and Confidential 9 The Fiber & Copper Co. gives a great flexibility to operators Proprietary and Confidential 10 5

6 FTTC: Just an example Proprietary and Confidential 11 Part 2 Evolution of the needs Need an evolution 6

7 New app every day Proprietary and Confidential 13 Proprietary and Confidential 14 7

8 Access technology growth VDSL2 100 Mbps ADSL2+ 24 Mbps ADSL 8 Mbps HDSL 2 Mbps ISDN 128 Kbps Proprietary and Confidential 15 New era for the copper pair John Cioffi, now a Stanford Professor, founded Amati and developed Discrete Multi-Tone technology (DMT) based equipment that in 1993 had dramatically better results than all competitors in Bellcore testing and became the most common standard. Proprietary and Confidential 16 8

9 The idea behind DMT Separates the signal into multiples sub-carriers (bins) Each bin transports a piece of the digital information Self-adaption to the quality of each subcarrier Well defined bandwidth between Downstream and Upstream Proprietary and Confidential 17 Some DMT figures Number of Sub-Carrier (SC) = SC are centered at f= khz SNR (Signal-to-Noise-Ratio) is the key Dynamic Rate Adaptation Max number of bit per bin is 15 Complex QAM and FFT technologies ITU-T Rec. G (01/2005) cp The signal-to-noise ratio SNR(f) for a particular subcarrier is a real value which shall represent the ratio between the received signal power and the received noise power for that subcarrier. Proprietary and Confidential 18 9

10 DMT bit loading concept Bit Loading, more information is sent in the SC with the best SNR Flexibility, it is possible to switch off single SC Proprietary and Confidential 19 Part 3 Test challenge IPTV services 10

11 Subscriber (M) IPTV Growth Adoption of IPTV Telco IPTV Subscribers by Region CY08-CY Telco IPTV Subscribers by Type CY08-CY13 CY08 CY09 CY10 CY11 CY12 CY13 Pure IPTV Hybrid IPTV/over-the-air Hybrid IPTV/QAM Over-the-top video is not IPTV CY08 CY09 CY10 CY11 CY12 CY13 North America EMEA APAC CALA Proprietary and Confidential 21 IPTV Ecosystem Proprietary and Confidential 22 11

12 IPTV: 7 steps video process 1 Digitizing Analog content 2 Encoding Digital video 3 Encapsulating in IP packets 4 Transporting IP video content 7 Converting to analog 6 Decoding digital content 5 Removing content from IP packets Proprietary and Confidential 23 Digital Encoding Compression Rates PAL Standard Definition TV video High Definition TV video Digital Video Encoding / Compressing format Pre-compressed Bandwidth Requirement Compressed Bandwidth Requirement Pre-Compressed Bandwidth Requirement Compressed Bandwidth Requirement MPEG2 250 Mbps 2-6 Mbps 1250 Mbps 8-20 Mbps MPEG4 (H.264 part 10) 250 Mbps 1-3 Mbps 1250 Mbps 4-10 Mbps VC Mbps 1-3 Mbps 1250 Mbps 4-10 Mbps SD image = 25 frames per sec X (576 rows X 720 columns X 24 bits) HD image = 25 frames per sec X (1080rows X 1920 columns X 24 bits) Proprietary and Confidential 24 12

13 MPEG-2 video coding Compression based on processing 8x8 pixel blocks Proprietary and Confidential 25 MPEG-2 video coding Only changing area have to be coded Proprietary and Confidential 26 13

14 MPEG-2 video coding Compression using motion vector Proprietary and Confidential 27 MPEG-2 GOP structure (GOP = Group Of Pictures) Intra-coding I pictures Forward prediction P pictures Bidirectional prediction B pictures Proprietary and Confidential 28 14

15 MPEG-2 TS Transport stream (TS) is a format specified in MPEG-2 Part 1 (ISO/IEC standard ) which contains seven packets of 188 bytes each (184 bytes of payload and 4 bytes of packet header) TS can also be utilized to transport MPEG-4 encoded video Proprietary and Confidential 29 MPEG Transport Stream structure Multi-program transport stream (MPTS) The packet ID (PID) is part of that 4-byte header and represents a unique address identifier for the type of packet or payload carried by the TS. Video or audio packets in the stream need to have a unique PID. This allows the decoder or STB to process the packets accordingly. Proprietary and Confidential 30 15

16 Header (4 bytes / 32 bits) MPEG Transport Stream structure Source: IP Television Ma Proprietary and Confidential 31 IPTV over the network Head End TS TS TS TS IP IP IP IP IP IP IP IP IP IP IP IP Ethernet/ATM DSL Optical STB TS = MPEG2 Transmission Stream Core Access network DSLAM Last mile Edge Last mile Home Proprietary and Confidential 33 16

17 Part 4 Ensuring Quality of Experience All is about Quality of Experience Quality of experience (QoE) refers to the overall IPTV user experience, including application responsiveness, functionality, usability, and the service context that surrounds it. Video quality of service (V-QoS) refers to the error-free video delivery from the operator s facilities to the customer s premises. Video quality (VQ) refers to the video content itself. Often the QoE of a customer is only known when he calls to complain or when subscription revenue drops needed! Analysis and Realization of IPTV Service Quality Bilgehan Erman and Elissa P. Matthews Proprietary and Confidential 35 17

18 Scope of error analysis Scope of Quality of Experience V-QoS A/V source Encoder / multiplexer Core Network Aggregation Network Access Network Home Network Decoder STB [1] A/V monitor VQ Scope of the error analysis VQ Video Stream QoE = (Quality of the Network Delivery System + Quality of the Encoding Components to the Network + Quality of the Decoder from the Network + Human Factors) per unit time [1] STB = Set Top Box Proprietary and Confidential 36 Quality of Experience Video content is encoded and compressed into transport streams, which are mapped into IP packets for transport across the network. As the packet transitions through the network it is subject to: Packet Loss: loss of packets Jitter: variation in arrival times Latency: delay in packet arrival due to congestion or routing Proprietary and Confidential 37 18

19 Quality of Experience Quality of Experience Depending on which type of problem you have and which frame is corrupted, you may experience different problems. Resulting in tiling, frozen frames or complete loss of picture Jitter Effect Packet Loss Effect Out-of-order Effect Proprietary and Confidential 38 Packet Loss It is the failure of one or more transmitted packets [of data] to arrive at their destination and is typically cited as a percentage. Loss of IP packets (ultimately those carrying MPEG information) may occur for multiple reasons Network congestion (over-utilization, over-subscription, hand-offs between carriers, bandwidth limitations) Higher priority traffic blocking lower priority traffic Network equipment problems (failed switches, routers, etc.) Setting / configuration problems (10/100 Mbps mismatches, use of duplicate IP addresses, etc.) Video equipment issues (transmission errors) Cabling issues (wiring issues, failed links issues) Proprietary and Confidential 39 19

20 Packet Loss Depending on the type of transport protocol used for the video streaming, a packet loss will affect the quality of the perceived video differently. When UDP is used, the lost packets will directly affect the image since the information cannot be recovered and the image will be corrupt or unavailable. When transmission control protocol (TCP) is used, a packet loss will generate a retransmission, which can produce a buffer underflow that may result in a frozen image. Proprietary and Confidential 40 Packet Jitter It is the variation in arrival time between packets. A constant rate of packet arrival is preferred However, the IPTV system can accept a certain amount of jitter too much jitter will result in lost packets. First Last TX IP IP IP IP IP IP IP RX Arrival Time t1 t2 t3 t1=t2=t3 Ideal case with constant arrival time (no jitter), no packet loss and no error. RFC 3550 Proprietary and Confidential 41 20

21 Impact on the quality Too much jitter will result in lost packets. The impact of packet loss on an IP video call depends upon a number of factors including: The percent of packet loss The distribution of the packet loss over time The capabilities of the endpoints / devices (STB) Packet loss causes voice clipping and skips, often resulting in choppy and sometimes unintelligible audio. First Last TX IP IP IP IP IP IP RX t1 t2 t3 t1 t2 t3 Real case with not constant arrival time (packet jitter), packet loss and errors. Proprietary and Confidential 42 Program Clock Reference (PCR) Inside the MPEG Transport Stream, it is carried out also synchronization information. This clock synchronization information is called PCR PCR info is instantaneous value or sampling of the original 27MHz system clock (STC). PCR info allows the MPEG decoder to recovery the original clock. Proprietary and Confidential 43 21

22 Program Clock Reference (PCR) TX RX Video input Video encoder DSLAM PCR IP IP IP PCR Video Audio 27MHz STC PCR Video Audio Video decoder 27MHz PLL Proprietary and Confidential 44 Program Clock Reference (PCR) Jitter It is the difference between measured arrival time of last bit of the PCR counter and the expected value of the PCR. Expected arrival time is derived from the PCR counter value inside the MPEG packets ETSI TR Proprietary and Confidential 45 22

23 Media Delivery Index Media Delivery Index (MDI) is an index of quality of service (QoS). Measurements serving as indicators of problems in the network that can be proactively addressed before it becomes a service affecting issue One of the key benefits - does not perform any type of stream decoding to achieve its metrics and therefore it does not require significant real-time processing power. MDI uses packet level metrics so it can be used to validate network equipment such as switches and routers RFC 4445 Proprietary and Confidential 46 MDI and Quality of Service MDI is expressed as Delay Factor (DF) and Media Loss Rate (MLR) DF indicates how long a data stream must be buffered or delayed at its nominal constant bit rate to prevent packet loss MLR is a measurement of the number of lost or out of order media packets (transport streams) over a selected time interval. MDI Low/Good QoE 10:0 MDI High/Bad QoE 122:8 MDI Low/Good QoE 5:0 Proprietary and Confidential 47 23

24 Set Top Box Initialization Channel Selection Head End Channel 208= IP packet: Channel 208= IP packet: Customer profile IPTV Middleware Broadband Core Network Access Network Set Top Box Home Network Set Top Box is auto-discovered by the middleware / network (DHCP) and middleware downloads the STB client software configuration When customer selects a video broadcast channel, the STB launches a request (IGMP) to connect to the appropriate IP port in the network Proprietary and Confidential 48 Zapping time - IGMP in Action FOX MPEG IGMP Leave FOX IGMP Query IGMP Join CNN CNN MPEG IGMP CONTROL POINT NETWORK FOX CNN HBO Proprietary and Confidential 49 24

25 Impact of IGMP Delays Proprietary and Confidential 50 Performance Indicators (IPTV delivery) Parameter Acceptable Marginal Unacceptable MDI Delay Factor (ms) 9 to 15 * de-jittering of STB allows for higher DF > 50 MDI Media Loss (fps) 0.02 to.05 >.05 Packet Jitter (ms) < > 30 Packet Loss (%) < to 1 > 1 PCR Jitter (ms) > 10 Zap Time (ms) < > 400 Proprietary and Confidential 51 25

26 Part 5 EXFO solutions by application The AXS-200/600 series IPTV service testing VoIP service testing Data service testing Provisioning Troubleshooting Installation Maintenance AXS-200/600 Pre-qualification work order customer-specific tests CUSTOMIZATION workforce automation taskforce bluetooth PROFILE triple play easy to use OPEX close-out test test-head support time saving job note collect results set OSS integration DATA MINING Proprietary and Confidential 53 26

27 AXS-200/650 Applications Ethernet Triple Play Testing Triple Play Services AXS-650 CENTRAL OFFICE DSLAM Application Ethernet service verification Data service verification IPTV Analysis VoIP Analysis AXS-650 DSLAM REMOTE TERMINAL xpon Ethernet Triple Play testing expands products capability Proprietary and Confidential 54 AXS-200/650 Applications RIGHT TOOL FOR PON (FTTH)! IPTV Service testing MPEG2/4 TS, WM9/VC-1 Bandwidth usage IGMP and STB Info IGMP Emulation Packet Loss, Jitter counter Graph & tabular output Zap Time QoS Pass/Fail Indicators VoIP Service Testing Monitors SIP, MGCP, SCCP Call Flow Codec indicator Packet Loss, Jitter counter Delay counter Graph & tabular output QoS Pass/Fail Indicators Data Service Testing PPPoE, PPPoA, IPoE, IPoA Tx / Rx counters PING, Traceroute WEB (HTTP) and FTP speed tests ATM Setup & Statistics VPI VCI, OAM Loopback Basic IP Service Verification Errors, TX / RX counters, PPP, IP, DHCP & Static IP address Fiber Optic Inspection Probe Proprietary and Confidential 55 27

28 AXS-200/600 Applications Fiber Inspection Probe Fiber Connector Inspection Cleaning is one of the most neglected operations but it is the most important one Remember also to clean the connector which you connect to. This must be done at LT,NT, ONT, splitter and ODF. Permanent damage can occur on dirty connectors when high power signal is turned on! Proprietary and Confidential 56 AXS-200/600 Applications Data Login provides PPP, IP, and bridged Ethernet encapsulation methods and support PAP/CHAP authentication. Ping user definable address, packet size and number of attempts. Reports success or failure. Traceroute user definable address, number of hops. Reports success or failure HTTP/FTP test determine access to user definable web and FTP server address (URL or IP address) Proprietary and Confidential 57 28

29 AXS-200/600 Applications IPTV STB Emulation emulates Set Top Box (STB) for joining/leaving channels and zap time analysis Codec Independent works in environments using MPEG-2, MPEG-4, H.264, and Microsoft codecs Metrics PID Viewer, PCR Jitter, Packet Loss, Packet Jitter, Zap Time Proprietary and Confidential 58 AXS-200/600 Applications IPTV Media Delivery Index Supports RFC4445 (MDI) and displays Delay Factor and Media Loss Rate. Can be used on conjunction with the EXFO FTB-8510B which provides MDI measurements in the network core QoS Pass/Fail Quickly see whether the circuit passes or fails based on user definable thresholds Proprietary and Confidential 59 29

30 AXS-200/600 Applications VoIP Monitor Monitor VoIP calls to ensure correct Caller ID, call flow, and codecs (G.711, G.729, G.726, G.723) Metrics View Packet Loss, Jitter, and Delay distribution graph QoS Pass/Fail Quickly see whether the circuit passes or fails based on user definable thresholds Counters Duplicated or Out Of Sequence packets, Invalid received packets Proprietary and Confidential 60 Thanks! 30