INCA

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INCA

  1. 1. Project Number: 248495 Project acronym: OptiBand Project title: Optimization of Bandwidth for IPTV Video Streaming Deliverable reference number: D1.1 Deliverable title: Functional Specification document Due date of deliverable: M4 Actual submission date: 12 May 2010 Start date of project: 1 January 2010 Duration: 30 months Organisation name of lead contractor for this deliverable: Telecom Italia Lab Project co-funded by the European Commission within the Seventh Framework Programme (2007-2013) Dissemination Level PU Public X PP Restricted to other programme participants (including the Commission Services) RE Restricted to a group specified by the consortium (including the Commission Services) CO Confidential, only for members of the consortium (including the Commission Services) The research leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement n 248495
  2. 2. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 Project history This page is used to follow the deliverable production from its first version until it is approved by all involved partners. Please give details in the table below about successive releases: Release Date Reason of this release Dissemination of this release (task number and/or validation level, WP/SP level, Project Office Manager, Steering Committee, etc) V1 08-04-2010 Draft Version WP level V2 16-04-2010 Second draft Management Support Team V3 19-04-2010 Third draft WP leader V5 12-05-2010 Deliverable WP deliverable OptiBand Public 2 OptiBand Consortium
  3. 3. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 Table of Contents Table of figures .......................................................................................................................................... 4 Glossary ..................................................................................................................................................... 5 1. Executive Summary ........................................................................................................................... 6 2. Requirements ..................................................................................................................................... 7 2.1 Overview of the evolution of IPTV platforms ................................................................................ 7 2.1.1 Business aspects .................................................................................................................... 7 2.1.2 Technology aspects ................................................................................................................ 8 2.2 Components of the IPTV chain ................................................................................................... 9 2.2.1 Server architecture................................................................................................................ 11 2.2.2 Network architecture ............................................................................................................. 12 2.2.3 Metro and access network..................................................................................................... 13 2.3 Foreseen network architecture.................................................................................................. 15 2.3.1 Packet-Drop Algorithm at Edge device .................................................................................. 15 2.4 Functional requirements of the System ..................................................................................... 19 2.4.1 Business requirements .......................................................................................................... 19 2.4.2 Technology requirements ...................................................................................................... 19 2.4.3 User requirements ................................................................................................................ 22 2.5 Operator’s remarks ................................................................................................................... 27 2.6 Definition of relevant use cases ................................................................................................ 29 2.6.1 Typical scenarios .................................................................................................................. 29 2.6.2 Specification of Optiband user testing setup .......................................................................... 30 2.6.3 Success criteria..................................................................................................................... 31 3. Conclusions...................................................................................................................................... 33 4. Bibliography ..................................................................................................................................... 35 OptiBand Public 3 OptiBand Consortium
  4. 4. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 Table of figures Figure 1: Server architecture ...................................................................................................................... 11 Figure 2: Network architecture ................................................................................................................... 12 Figure 3: Metro network (BTV distribution) ................................................................................................. 13 Figure 4: Metro network (Edge VoD servers) .............................................................................................. 14 Figure 5 - Simplified IPTV Network ............................................................................................................. 15 Figure 6 - IGMP Modes .............................................................................................................................. 16 Figure 7 - IGMP Proxy for Multicast Channels ............................................................................................ 17 Figure 8 - Mapping IP Multicast to Physical MAC Address .......................................................................... 17 Figure 9 - Multicast MAC to Unicast MAC................................................................................................... 18 Figure 10 HD Channels available in Europe by country of origin [2] ............................................................ 24 Figure 11: TV viewing habits regarding VOD vs. LiveTV[5] ......................................................................... 25 Figure 12: HD channels available in Europe by genre [2] ............................................................................ 26 OptiBand Public 4 OptiBand Consortium
  5. 5. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 Glossary Abbreviation Reference ADSL Asymmetric Digital Subscriber Line AVC Advanced Video Coding CDN Content Delivery Network DAM Digital Asset Management DRM Digital Rights Management DSL Digital Subscriber Line DTT Digital Terrestrial Television DVB Digital Video Broadcasting ETSI European Telecommunications Standards Institute FEC Forward Error Correction HD High Definition IEEE Institute of Electrical and Electronics Engineers IGMP Internet Group Management Protocol ISP Internet Service Provider IPTV Internet Protocol Television ITU International Telecommunications Union Mbps Mega-bits per second MPEG Moving Pictures Expert Group MPEG-TS MPEG Transport Stream PVR Personal Video Recorder QoE Quality of Experience RTP Real Time Protocol RTSP Real Time Streaming Protocol SD Standard Definition SMS Service Management System STB Set Top Box SVC Scalable Video Coding TS Transport Stream VDSL Very high speed Digital Subscriber Line VOD Video On Demand OptiBand Public 5 OptiBand Consortium
  6. 6. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 1. Executive Summary This deliverable is the output of the activity performed in WP1 of the OPTIBAND project. The objectives of this WP were: To define the functional specifications of the system, including business aspects and technology aspects To define use cases and success criteria for system testing The job included collection and integration of requirements on business and technological aspects and user perspectives to build the functional specifications of the content aware data drop algorithm. It was decided to consider HD live and on demand contents and attention is paid to them only, even if the IPTV service will continue to include distribution of both SD and HD contents during the years of life of the project. A second target WP1 was to define typical use cases, which are typical scenarios that are characteristics of the operation of the system. For each use case, success criteria will be defined which will be verified during the demonstration. This document will serve as the basis for the live demonstration testing plan at the end of the project. The document includes some remarks from the point of view of an operator. Since TI is the only operator who participates in the project, its experience is considered a meaningful case study and the issues it raises of general interest and reliability. The document is built of three sections:  A first one simply summarizes the foreseen evolutions of the IPTV service, both in the business and in the technology aspects. It comes from the TI plans for the near future but we can state that it is a study case which well describes a general evolutionary framework. Most of the elements are certainly outside the scope of the project. It is up to the project to pick up only the aspects which are relevant for its purposes.  The main one is the list of the requirements of interest for the future developments in the project on several topics: network aspects, encoding aspects, user aspects,…etc.  A third one is a brief description of some use cases, willingly few and as simple as possible but consistent with the indications in the OPTIBAND technical annex document, and the success criteria to follow to validate the results of the project. OptiBand Public 6 OptiBand Consortium
  7. 7. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 2. Requirements 2.1 Overview of the evolution of IPTV platforms This chapter simply summarizes the foreseen evolutions of the IPTV service, both in the business and in the technology aspects. It comes from the TI plans for the near future but we can state that it is a study case which well describes a general evolutionary framework. Most of the elements are certainly outside the scope of the project. It is up to the project to pick up only the aspects which are relevant for its purposes. The remaining of this document will focus only on the specific aspects which have impact on the project results. 2.1.1 Business aspects  Some are straightforward  BTV (MULTICAST, SD/HD): live TV both in SD and HD.  VOD (RTSP/HTTP STREAMING, SD/HD): content on-demand distributed in streaming using the protocols “RTSP” currently used in the AHTV service. (AHTV stands for Alice Home TV, the brand of the IPTV commercial service by TI)  TI thinks about using HTTP as the streaming protocols in the next version of the STB  ENHANCED EPG: guide of the programs. The present version integrates the “free and premium” contents from different broadcaster. The next development foresees specific EPG for each broadcaster (SKY - MEDIASET..).  FAVORITE CHANNELS: possibility to create lists of preferred channels.  SEARCH (VoD and LIVE): VoD research and research of programs or channels for the Live. Researches are based over the “metadata” associated to the single contents.  DTT (FREE/PREMIUM): Digital Terrestrial TV channels free-to-air and premium channels (encrypted).  Some are enhancements of existing audio/video services  PVR - Personal Video Recorder: the choice is for “local PVR”. Therefore the contents are recorded on the hard disk of the STB.  DOWNLOAD&PLAY: service based on the possibility to transfer content on the hard disk of the STB and the possibility to subsequently enjoy of it. It is an alternative to the streaming, useful when the available bandwidth wouldn’t be enough.  S-VOD subscription VoD: subscription to a set of VoD contents, which will be periodically updated by the operator  VOD BUNDLE: offer that allows seeing a certain number of VoD contents to a reduced price.  Some are Internet TV services  WEB-TV: logging to web content like YouTube, with a consumer experience similar to internet.  WIDGET: television applications with a consumer experience similar to internet.  The actual widgets include Finance, Weather, News and Horoscope.  MEDIA SHARING (UPnP/DLNA): possibility to share contents (photo, music and video) that are on other devices of the domestic network using protocols like UPnP and DLNA. OptiBand Public 7 OptiBand Consortium
  8. 8. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010  APPLICATION STORE: catalogue of internet applications like flicker (photo album), twitter (chat), and applications of “T-government” (access to all the services that the public administrations. E.g.: to book medical visits, to request certificates, to pay bills)  COMMUNITY SERVICES: services of messaging and chat (facebook).  Some are new functionalities, currently non implemented in the platform  NEXT TV (TV OF YESTERDAY): possibility to see television content broadcasted in the past days and recorded by the operator  TIME SHIFTED TV: pause a live content and take back its playing from the interrupted point  RECOMMENDATION: the system proposes to the consumer some contents with criteria of the type “similarity” of contents, similarity based on consumer selections and purchases.  ADVERTISING: publicity both on the live contents that VoD. 2.1.2 Technology aspects  About the encoding  The encoding should be primarily in charge of the operator itself. In this case the configuration of the encoders will be completely under control and knowledge of the operator. This is true both for live contents and for VoD, the last ones being produced in the DAM environment of the operator. In case the encoding process is carried out by content providers or ISP or broadcasters it must be assumed that the way it’s handled is agreed in a SLA which will define the encoding configuration, to guarantee the requested QoE.  The H.264 encoding technology can still have improvements in the next few years. For this reason the encoding bitrates can be foreseen to decrease below their current values. As far as HD is taken into account, one could guess for instance that in a couple of years the video bitrate in case of the 1080i format will go down to 6 Mbps for all kinds of contents keeping a good QoE.  1080p is not fully available yet either for encoders or for source contents. That format could become more common in the project’s timeframes.  The zapping time (which is currently about 1.5 - 2 s) in no longer considered a critical requirement by marketing people. So, it doesn’t put strong requirements on the GOP structure.  Newer audio encoding technologies like HE-AAC or decoding Dolby-E sources (now it can be only pass-through) should become available on all encoders  About the network architecture  The network architecture for VoD is already geographically distributed, including a Central VoD server in the head-end e a series of Edge VoD server located in the PoP all over the country (They are 32 in the TI actual architecture). Currently each Edge VoD server acts simply as a cache, keeping a copy of most of the VoD titles. Activities are in progress to build a true CDN (Content Delivery Network) with more advanced logics for the distribution of contents.  The STB joins a new live channel by issuing an IGMP request for a multicast group, after having checked that it is entitled to ask for that channel with the middleware. OptiBand Public 8 OptiBand Consortium
  9. 9. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 No selection of the transport port is available. The IGMP request is relayed by the DSLAM back to the Feeder router, where it is served. Static multicast flows go down from the headend to the any feeder in the metro network; the multicast flow is dynamic from the feeder to the STB.  The protocol stack currently in use to convey the audio/video payload is UDP/IP in multicast for live channels and in unicast for VoD contents (VoD uses RTSP to control the session). In case of support of FEC a new specific client should be integrated in the firmware of the STB and the support of RTP should be enabled.  About the recovery of network impairments  Recovering audio or video artifacts due to network impairments is a high priority for the acceptance of the service by the users.  The target is to allow no more than 1 artifact per hour.  Different technologies for error recovering are under development and evaluation for their advantages and disadvantages (overhead). Examples are: physical layer retransmission, application layer PRO-MPEG FEC, application layer retransmission.  Error resilience features available in H.264 for the Main and the High Profiles (Intra Coded Macroblocks, Frame segmentation into Slices, Constrained Texture Prediction,…etc.) should be deployed by the encoders to get the same quality of experience (QoE) which is achieved when using MPEG-2. At the moment no encoder is known to implement them. It should be assumed that error concealment is supported by the decoder.  About the user device  User devices are evolving from simple STB without hard-disk to a more complex appliance which supports either IPTV and DTT and WebTV. It has hard-disk to allow local PVR or content’s acquisition in D&P. It can input and manage local and personal media contents (through USB). The display is the TV-set connected through the HDMI interface (SCART interface no longer supported) TI is promoting a new device of this kind called “Cubo” (The cube) See www.cubovision.it for details.  The collection of statistics from the devices in the user’s premises (AG and STB) is planned to be carried out using TR-135 and TR-069. A simplified profile is selected for TR-135. Experience shows that those standards are redundant and heavy for the need and purposes of managing the devices in the IPTV environment. Integration and analysis of data in an ACS server is an activity still in progress. 2.2 Components of the IPTV chain The following list and the associated pictures recap the components in the typical IPTV chain. The pieces of equipment under development by the project will have to find the most effective location in the sketched architecture.  Tagging of the TS packets should be done in the headend. Tagging of the TS packets shouldn’t affect the encryption process. On the other side, the tagging of the TS packets must suit with any DRM in use in an IPTV platform. OptiBand Public 9 OptiBand Consortium
  10. 10. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010  New application servers to fulfil the needs identified in the project can be added in the headend and be considered part of the middleware. It means that they have to be designed taking into account the proprietary API of the other components of the middleware. For instance a “network middleware server”, if required, which is in charge of controlling all the STBs in the distribution network, retrieving the information from the DB of the SMS server, and is in charge of detecting which content is played by any STB at any time.  The data dropping piece of equipment should be placed reasonably close to the xDSL link. The precise position will depend on the way the algorithm will be implemented and the information the equipment will need to carry out its job.  The deployment of the algorithm must be applied to any STB an operator has selected for its IPTV platform, with no change or at least with an upgrade of the STB’s firmware. The choice of the STB is strictly tied to the DRM system and the middleware, so they cannot be changed when new functionalities are added.  The inclusion of the new equipment in the existing network must take into account the scalability, throughput and legacy constraints for the operator. Any new technological solution which doesn’t respect the above reasons would largely decrease the possibility of an actual use in real IPTV solutions.  Headend  Content sources  IRD for satellite inputs  Live Encoders based on AVC solution,  Offline encoders for which a solution based on SVC will be investigated  DAM system Digital Asset Management  VoD Ingestion  CA/DRM system (Conditional Access/Digital Rights Management)  Application server (IPTV Middleware + Database): SMS (Service Management System) and transactions server CMS (Content Management System ) e.g.: metadata management EPG and channel management ………  Access to OSS/BSS (Provisioning, Authentication, Billing, Assurance, etc.)  Other Application Servers (Recommendation, AD insertion, …)  Network  Transport network  Metro network  VoD Server  Access network  Dslam  xDSL link  Home premises  Access Gateway  Home network (Ethernet, Power-lines, Wi-Fi)  User devices o STB and TV-set o Decoder devices on PC  User OptiBand Public 10 OptiBand Consortium
  11. 11. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 2.2.1 Server architecture Figure 1 show how the components of the IPTV chain are located in the network architecture and which servers are required to build an IPTV platform. Most of them are located in what is called the HeadEnd, which includes the encoders, the DRM system and the application servers. Only for VoD servers the architecture is geographically distributed. The picture also shows the need of interfaces towards the Operator’s legacy BSS/OSS systems for statistics, assurance and billing. Figure 1: Server architecture OptiBand Public 11 OptiBand Consortium
  12. 12. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 2.2.2 Network architecture Figure 2 shows the network architecture which consists of four components:  The transport network: an optical backbone and its border routers.  The metro networks: regional areas below the PoP with 10 Gigabit IP links between routers.  The access network below the Feeder router with DSLAMs and ADSL links.  The home network in the house, below the AG. It can be based on different technologies (Ethernet, Power Lines or Wireless). Figure 2: Network architecture OptiBand Public 12 OptiBand Consortium
  13. 13. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 2.2.3 Metro and access network Broadcast TV distribution (IP multicast) Figure 3 shows the structure of the metro area network in more details. It reports the path the multicast flows follow from the HeadEnd (IPTV HE) and highlights that the path is static up to the Feeder router and the dynamic from the Feeder to the DSLAM. Figure 3: Metro network (BTV distribution) OptiBand Public 13 OptiBand Consortium
  14. 14. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 Metro network and edge VoD servers Figure 4 shows the structure of the metro area network in more details and reports how the VoD unicast flows are handled from the distributed Edge VoD Servers to the STB. The cluster of redounded Edge VoD servers and their Eth switches are located in the PoP. Figure 4: Metro network (Edge VoD servers) OptiBand Public 14 OptiBand Consortium
  15. 15. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 2.3 Foreseen network architecture The most critical choice to be addressed in designing the network architecture for an IPTV solution which includes the OPTIBAND data dropping functionality is the location of the dropping equipment in case of live contents. The intention is to describe possible solution of implementing the Packet-Drop algorithm (PDA) at the Edge device. Edge device is the network element located at the metro-access edge; it aggregates many DSLAMs access devices and connects them to the Metro area. Implementing the PDA at the Edge device has implications on the control plane (signalling protocols) and data-plane (mainly on Layer2). 2.3.1 Packet-Drop Algorithm at Edge device IPTV Network Description The figure below illustrates a simplified IPTV network, which shows the location of Edge device and the Access devices (DSLAMs). The access devices provide DSL links to households, each may have different access rate, depends on the DSL technology (ADSL, ADSL2+, VDSL, etc.), distances, and the profile that each user has with its ISP. DSLAM may connect from few to hundreds of end users to the network. The Edge device can aggregate many DSLAM devices and connects them to the Metropolitan Area Network (MAN) which also provides the CDN services to the IPTV users. Figure 5 - Simplified IPTV Network OptiBand Public 15 OptiBand Consortium
  16. 16. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 Control Plane For broadcast TV (BCTV) channels, the IPTV STBs are configured with the IP multicast address associated with each broadcast channel. The following table provides an example: Channel IP Address Ch#1 230.0.0.1 Ch#2 230.0.0.2 Ch#3 230.0.0.3 … … When end user zap between channels, its STB sends IGMP messages towards the network to inform the IPTV network that it changed channel, meaning, it leaved the multicast group associated to previously viewed channel and joined a new multicast group associated to the new requested channel. For example: A user that zaps from Ch#1 to Ch#2, its STB will generate: IGMP Leave 230.0.0.1 IGMP Join 230.0.0.2 Note: The process of channels entitlement is ignored to simplify the proposal description. To allow the Edge device to perform the PDA correctly, it is required that the DSLAM devices are configured to operate in IGMP snooping mode, meaning, the DSLAM device that receives the IGMP messages from the user’s STB will only “sniff” the message, and will forward the IGMP message unmodified upward to the Edge device. By forwarding the IGMP messages to the Edge device, the Edge will be able to identify to which channel each STB is tuned, hence, will have the knowledge how many STBs behind each DSL link and which channel is currently viewed by each STB. To minimize the overload of IGMP messages on the network and on the multicast router, the Edge device will be configured as IGMP proxy, it sends a single IGMP message towards the multicast router for all IGMP messages received on DSLAM interfaces for each multicast channel. Figure 6 - IGMP Modes OptiBand Public 16 OptiBand Consortium
  17. 17. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 Data Plane Broadcast channels are distributed over the network, each channel is assigned with specific destination IP multicast address. The network nodes that operate in IGMP proxy mode receives all IP-multicast channels from the network side and forward only channels that were requested by its downstream users, user that were registered to the channel multicast group with IGMP messages. Channels that were not asked by downstream users will not be forwarded by the IGMP proxy nodes. Figure 7 - IGMP Proxy for Multicast Channels Each STB has a unique MAC address, the multicast channel access a group of STBs (those that were registered to this multicast group), by having multicast MAC address that is derived from the IP multicast address. To map an IP multicast address to a MAC-layer multicast address, the low order 23 bits of the IP multicast address are mapped directly to the low order 23 bits in the MAC-layer multicast address. Because the first 4 bits of an IP multicast address are fixed according to the class D convention, there are 5 bits in the IP multicast address that do not map to the MAC-layer multicast address. Figure 8 - Mapping IP Multicast to Physical MAC Address For example, the multicast address 224.192.16.1 becomes 01-00-5E-40-10-01. For OptiBand project, on one hand, we would like to keep the IP multicast unchanged to avoid any need for configuration at the STB devices and the IPTV middleware device. But on the other hand, we still would like to adjust the video channel to each user based on the user's access bandwidth constraints, since each user has different constrains, the Packet-Drop Device (PDD) is required to personalize the multicast channels and actually generate unicast video stream per STB. OptiBand Public 17 OptiBand Consortium
  18. 18. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 These two conflicts can be resolved by using Layer-3 multicast IP over Layer-2 unicast MAC. Where the Layer-3 multicast address is the channel multicast group identifier, all STBs on the IPTV network are configured with this multicast address for each multicast channel. The Layer-2 MAC is replaced by the PDD from multicast MAC to unicast MAC per destination STB. The PDD performs the MAC replacement for each STB, as illustrated in following figure: Figure 9 - Multicast MAC to Unicast MAC The DSLAM is a Layer-2 device, it manages a table of Layer-2 MAC addresses per interface by learning and aging MAC addresses of transported flows. The MAC learning is automatically done at the DSLAM by monitoring the source MAC addresses of flows that it forwards between interfaces. A DSLAM that receives a video channel from the Edge device, with IP-Multicast over MAC-Unicast will use its Layer-2 MAC table to perform the forwarding decisions of the channel’s packets to the specific user’s STB based on the destination unicast MAC address value. In this case, the DSLAM doesn’t access the Layer-3 IP multicast address and it doesn’t use the Layer-3 to perform any forwarding decision. The STB that receives the multicast IP channel, over unicast MAC address will pick up the packets and will decode the video content and will present it at the appropriate channel according to the IP-Multicast address. Despite of its location, the “OPTIBAND data dropping” resource needs to get the information about the current state of the STB. This information can be thought as the sum of three components:  Static and administrative information about the STB: its MAC address, the kind of contract the subscriber has purchased, the subscriber’s profile, the number of devices in the household, the nominal rate of the ADSL link (as evaluated by the operator at the time of subscription) …. All these elements can be retrieved from the middleware, in particular from the DB associated to the SMS server, and need to be refreshed at very low frequency.  Dynamic information about a new requested content. If a live channel is requested, the information can be retrieved from the IGMP requests only is the data dropping resource is located within the L2 domain between the STB and the feeder, otherwise it can be retrieved sniffing the proprietary http traffic between the STB and the middleware, which happens prior to making the IGMP request. If VoD content is requested, the information must be retrieved using the protocols specific for handling VoD sessions (e.g. RTSP). Attention must be paid to the geographical distribution of the VoD server architecture: most of the contents are actually supplied by the edge VoD servers.  Dynamic information about the actual immediate available bandwidth for a new requested content. This information is of course available in the DSLAM, but it is not exported. It could be retrieved from the AG querying it using the TR-069 protocol, but the use of this protocol is rather heavy. OptiBand Public 18 OptiBand Consortium
  19. 19. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 2.4 Functional requirements of the System 2.4.1 Business requirements The project decided to focus on HD contents both live and on demand. The considered encoding technology is H.264/AVC for supporting current STBs in usage and scalable extension of H.264/AVC (SVC) for future generations of IPTV system and STBs. MPEG-2 is considered a mature and obsolete standard, limited to the SD world in the IPTV environment. The choice of providing for a new feature referred to HD is a business choice, because theoretically the algorithm must apply both to HD and SD encoding in the same way. The choice derives from the forecast of a growing request for HD contents, a large diffusion of full-HD TV sets and the marketing trend to offer premium contents mainly in HD. It is worth reminding that the service will still be a mix of contents in SD and HD during the life time of the project. 1080i, 720p and 1080p are the video formats to make reference to. At the time being, no commercial live H.264 HD encoder is supporting the 1080p format. There is a chance that the availability of 1080p will grow in time: many TV monitors already support it, Blu- ray discs can be played in that format, …etc. For these reasons it would be advisable that the deployment of the dropping algorithm will work with both formats. 2.4.2 Technology requirements Encoding requirements New layered coding technologies are all far from deployment (mainly owing to the lack of SoC to build new STBs). Among them only SVC and MVC are worth considering as long term solutions and will be investigated by the project (see deliverable D3.1 for details). Live contents The setting of the encoding parameters cannot be the absolute best a technology can provide for, but it must be a trade-off among several conflicting exigencies: a good available QoE but considering the bottleneck of the access network, the objective of reaching the highest possible number of users over the access links, the number of services which the marketing people ask to offer over an IPTV platform (data, VoIP, Internet TV, widgets, …) Usually an operator carries out a set of quality laboratory tests to select the suitable configuration for its services. Considering the TI experience as a meaningful case study, the final setting of the parameters of the encoders is the result of the above process for the most relevant choices and of the suggestions by the encoder manufacturers for the details. Decisions are also affected by the improvements of the deployment of the encoding technology. This is still true for H.264 HD live encoders: hardware architecture is evolving and more performing firmware versions are released. For instance, the video bitrate decreased in the years keeping the video quality unchanged. Nowadays a good QoE is achieved even for challenging contents (soccer, action movies, ..) with a video bitrate of 8 Mbps in case of 1080i format; we can expect that the same quality will be achieved using 6 Mbps by the end of the project. For live contents the encoding process in many cases is carried out directly by the operator in its headend. The content providers feed the encoder’s input through an HD-SDI contribution. Under some circumstances the encoding can be carried out by a broadcaster or an ISP, but even in those cases the encoding configuration is decided by the operator to assure the uniformity of the distributed contents and the compatibility with the network infrastructure. OptiBand Public 19 OptiBand Consortium
  20. 20. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 The most relevant parameters which define the encoding and which are decided by the operator are: Parameters H.264 HD H.264 High Profiles H.264 Scalable Baseline H.264 Scalable High Level 4.1 (4.2 for 1080p optional) Video format 1080i, 720p (1080p optional) Video bitrate 7 (14 for 1080p) Mbps Mux bitrate Up to 8 (15 for 1080p) Mbps Rate mode CBR ,VBR GOP length TBD GOP structure TBD IDR frequency TBD Audio coding AC3 Audio bitrate 384 Kbps The above table has been filled with values which are considered mandatory for the operator. Specifically:  The Rate mode refers to the TS stream; it is advisory that the video elementary stream is in CBR mode too and that there is no stuffing  The audio parameters refer to any audio stream included in the TS stream (e.g. for movies it is common to have audio in two different languages)  The items which are labelled ad TBD (To Be Defined) can be discussed with the encoder manufacturer VoD contents The encoding process is performed off-line, generally starting from uncompressed sources on HDCAM tapes. It is carried out in the DAM environment and involves both the encoding itself, the management of metadata and the publishing policy. The encoding parameters are the same as in the live case (see the above table). The VoD content is previously encrypted and then ingested in the VoD server. It should be assumed that when a tagged VoD content is ingested into the VoD server, the server must remain unaware of the tagging. Content protection requirements The following requirements expressly refer in some bullets to the Irdeto content protection system, since Irdeto is a partner in the project. It is up to the partners involved in the development of the solution to integrate the content protection client in the selected STBs.  General:  Elements between the head-end and the STB should be transparent to the CA system.  Protected content shall not be re-scrambled between the head-end (scrambler) and the STB (descrambler). Re-scrambling is allowed in the STB for PVR functionality (outside scope of OptiBand project).  The dropping algorithm shall be able to work on a fully scrambled stream. OptiBand Public 20 OptiBand Consortium
  21. 21. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010  Head-end  It is advised that Encoders/Multiplexers support DVB Simulcrypt interface version 1.4 or above. This interface is described in ETSI TS 101 197 V1.4.1 chapter 5 (SCS <-> ECM generator interface)  The solution shall use TS (MPEG2), MPEG2 TS over IP  VoD content must be pre-encrypted; the pre-encryption is performed by the Irdeto Pre-Encryption Server as part of the integration components. After pre-encryption the content can be handled by industry standard VoD servers.  Encryption must use AES-128 algorithm and may use CSA algorithm. The CSA Algorithm is the DVB native enciphering standard and is designed to be software unfriendly to enforce the use of dedicated hardware.  The system shall guarantee the minimal bandwidth of 100kbps on the access network for the content protection system.  Any metadata that is not related to the CA system shall not be encrypted. The metadata added by the CA system will be encrypted with an Irdeto propriety encryption algorithm and is performed by the Irdeto Key Management System (KMS) as part of the integration components.  In-band transmission of Entitlement Control Messages (ECM) shall be supported.  The system shall guarantee transmission of at least one ECM per crypto cycle (one crypto cycle is 10 seconds).  Network  Networks shall support multicast for Entitlement Management Message stream. As a note the amount of required multicast addresses is dependent on the amount of subscribers yet is configurable.  EMM stream delivery shall have 90% success.  STB  STB middleware shall be integrated with Irdeto CA. It is preferred that the STB is integrated with Irdeto's universal client (software based security model), if required a Smart card security model can be chosen.  STB shall support AES-128 and/or CSA algorithms. This requirement relates to the encryption algorithm requirement for the head-end.  STB shall be a termination point for protected content. Platform requirements An IPTV platform is typically a vertical self-consistent application. There are very tight links among the components of any platform, since most of the API and interfaces are proprietary, so porting portions of software to different platforms is very heavy nowadays. This has an impact on the specific pieces of equipment which might be developed by the project. There is also a tight link between the platform and the selected STBs, since some interactions between the STB and the network middleware are not standardized, or there are several possible standards to choose. The most relevant integration for OptiBand involves the SMS (Service Management System). In the middleware of any platform there is an SMS server whose database keeps information about the subscribers, their STBs, their profile, the contents they can access, … This application server typically doesn’t trace what a STB is doing in real time (which channel or which video it is playing at that time). This means that it could be necessary both to query the DB and to implement some new and specific resource to feed the dropping equipment with all the information it needs to decide whether to file a stream or not. The OPTIBAND project will develop the middleware APIs needed to let the packet dropping algorithm query the required information about the STB status basing on existing standards, because the target is to decouple the packet dropping algorithm from any concrete STB or network middleware implementation. OptiBand Public 21 OptiBand Consortium
  22. 22. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 STB requirements The pool of STBs is one of the major investments by the operator in its IPTV deployment and then it must be safeguarded from changes. One of the goals of the project should be to demonstrate that the dropping algorithm can be supported by the existing STBs transparently. In the OPTIBAND project the candidate middleware will be provided by LambdaStream. The STB that will be used to assess the development of the Data Dropping algorithm and the deployment of the PDD will necessarily be integrated with the selected middleware as well as with the selected content protection system. Nevertheless, OPTIBAND will target to decouple the STB interacting with the network middleware, trying to increase the possibility of upgrading existing platforms extending the middleware application without requiring to replace the STB already deployed The middleware interface to the STB depends on the concrete middleware used. In this project we will try to provide any extra information that might be required using open standards whenever possible. For example, the standards developed by the DSL Forum (TR-XXX) might be candidates to let the head-end query the STB status. However, they are too heavy and redundant to be used by the project. Further they are not thought to provide information in real time. The project should find a different suitable way to get information about the free bandwidth on the DSL line non to be forced to rely only on static information about the STB and dynamic information about what it is playing, nothing about the current DSL rate. 2.4.3 User requirements This section presents important background information from market studies, stakeholder consultations and important standards (e.g., ITU-R BT.500-11 ‎20]), regarding the characteristics of OptiBand target users, [ relevant TV services and content, the user’s TV consumption environment, as well as end-user equipment. These are the basis for the specification of the OptiBand user testing setup (see section ‎ .6.2). 2 User characteristics When designing novel algorithms for IPTV, it is important to know who the target users of IPTV services are. US consumer research from 2009 ‎ 1] indicates a high share (44%) of households with higher incomes than [ $75,000. This reflects that IPTV currently only includes paid services and offer many additional pay services (e.g. VOD). Furthermore, the obtained data reveals a rather equal distribution of IPTV user characteristics in terms of gender and age. In Europe is very similar viewers’ distribution ‎ 2]. Moreover, there is no statistically [ significant viewers group in term of gender and age in Europe ‎ 2]. [ Gender Male 59% Female 41% Age Range 18-34 32% 35-54 36% 55+ 32% Average Age 44.9 Annual household incomes Less than $25,000 12% $25,000 - $49,999 20% $50,000 - $74,999 23% $75,000 + 44% Average Income $77,641 Table 1: US IPTV consumer research statistics (BIGresearch, 2009 ‎ 1]) [ OptiBand Public 22 OptiBand Consortium
  23. 23. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 As regards the selection of test subjects for QoE studies, ITU-R BT.500-11 ‎20] provides recommendations [ for sample size, expertise in video processing, and visual acuity (see below). Although, the consumption behaviour of young generation changes, due to new sources of information and entertainment (e. g. you tube, facebook, twitter …), TV services are still fighting their corner. Recent statistics from the European Audiovisual Observatory ‎2] show an increase in average viewing from 187 to [ 188 minutes worldwide. This rise was significant in Europe where the average viewing time went up from 215 (in 2007) to 218 minutes (in 2008). The viewing times in Europe are characterized by the significant differences. Although it is difficult to define coherent geographical grouping, the statistics ‎ 2] show that [ viewers living in the countries of northern Europe watch less television than those living in the east or south. The viewing times in Europe range from approximately 140 minutes a day (e.g. Austria, Swiss (D) to approximately 240 (e.g. Italy. Hungary). TV Services The British consumer statistics ‎ 5] already show the following preference for TV services: [  On digital terrestrial television (DTT), 48% receive the “Freeview” channels but no pay services, with a further 4% receiving pay services on DTT.  43% of respondents have access to some form of satellite television service.  19% of respondents appear to receive cable television services.  10.7 million were subscribers of IPTV within the European Community (EUR27) in 2008 ‎ 2]. [  EUR27 had 40% growth of penetration rate of IPTV service in 2008 ‎ 2]. [  Many consumers are already well equipped to take more control of their television viewing in the home, through the use of home digital recording technologies and/or the adoption of platforms which are capable of delivering content to the home on an “on demand” basis.  The increasing popularity of flat panel displays is evident from the 27% penetration of HD-ready television sets, given that there is a much lower ownership of devices capable of outputting high definition signals to these displays. Despite the financial crisis, 2009 was an exceptional year for TV sales in Europe. The main driver of this success was the introduction of HD TV sets and services in recent years. In Europe, there were approximately 274 HD channels (see Figure 10) ‎ 2]. [ OptiBand Public 23 OptiBand Consortium
  24. 24. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 Figure 10 HD Channels available in Europe by country of origin ‎ 2] [ HD channels are present at all digital platforms with satellite providing the most options. IPTV is also developing as a platform for HD. IPTV in general In Europe are only three markets (Albania, Malta and Turkey) that did not offer IPTV service. IPTV platforms are provisioning a substantial number of channels, in many cases more than hundred. Moreover, the rapid expansion of IPTV services has fostered the distribution of European channels between different markets as well as the prominence the non-European channels that have until now been available only via satellite (e.g. Arabic and Asian channels). In addition, the IPTV platforms provide additional services such as access to HD channels, chatch-up TV, video on demand (VOD) and digital video recording. For example, the biggest European IPTV provider SFR (FR) with 3.9 million subscribers offers 6 HD channels and 2 VOD services ‎ 2]. [ Huge success of IPTV was recognized in 16 countries of the European community where the penetration growth rate is higher than 100% (e.g. Austria, Czech Republic, Great Britain, Italy), and above 30% in the total of EUR27 ‎ 2]. European TV viewers spent nearly 1,5 billion Euros on their IPTV services in 2008 ‎ 2] and [ [ the market is still growing rapidly. Video on Demand (VOD) Market research focused at of TV viewing habits ‎ 5], ‎ 6] identified an increasing popularity of VOD. [ [ VOD services are gaining thanks to the multimedia technologies and services (see Figure 11) OptiBand Public 24 OptiBand Consortium
  25. 25. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 Figure 11: TV viewing habits regarding VOD vs. LiveTV‎ 5] [ The first massive launch of VOD services was in 2005. By the end of 2006, 142 paying VOD services were operational in Europe ‎ 7]. The growing usage of IPTV also entails an increasing usage of related Internet- [ based video services. About 30% of VOD providers are simultaneously IPTV providers and 57% of VOD services are provided in Internet environment. Therefore, it can be assumed that IPTV and Internet video services are becoming a significant part of the video service landscape. As users are increasingly willing to take more control of their television viewing in the home environment, user preference for VOD, IPTV services and increasing usage of home multimedia centres ‎ 5], ‎ 6]. [ [ From a QoE perspective, it is important to note that, it is the current state of knowledge; it is not clear whether there are different quality expectations for IPTV-based Live TV vs. VOD services. Content Content is an important mediating factor when assessing QoE. In the course of the development of a parametric IPTV video quality prediction model ‎11], ‎12], a large number of subjective tests have been [ [ conducted for Standard Definition and High Definition video with different types of content. One main result was that the content dependencies are different for different types of degradations. Therefore, the following content types have to be differentiated with regard to their influence on perceptual quality ‎13], ‎14], ‎15]: [ [ [  Soccer  Action movie  Movie trailer  Video clip  News  Panorama  Interview An internal market study by Telecom Italia conducted for the OptiBand project has revealed that the most popular contents watched on TV were sports (78%). The domination of sport contents is not surprising, given the consistent results of independent content popularity ratings ‎19]. The second- and third-most popular [ OptiBand Public 25 OptiBand Consortium
  26. 26. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 content types surprisingly show user preference for movies and documentaries video contents. This may indicate that full-HD users find important video quality of these two contents. This also confirms the recent market study focused at HD channel availability in Europe by genre ‎ 2]. The [ HD channel availability by genre (see Figure 12) reflects also the viewers’ preference for specific genres and contents. Sport and film channels each represent about fifth of HD channels available. This shows also the importance of this content for driving HD services. Figure 12: HD channels available in Europe by genre ‎ 2] [ End-user equipment According to an internal questionnaire study with their IPTV customers, Telecom Italia identified important information regarding currently predominant end-user equipment. The questions were related to user TV equipment, IPTV service quality. The following information we can derive from performed survey:  Flat panel TV sets dominate with 91 % share. This allows us to conclude that flat panel TV technology has already removed the CRT technology to history. Next interesting factor is domination of LCD technology with 73 % share in flat panels TV sets. This trend confirms also the recent market reports ‎18]. [  The 83 % of the TV sets support are already HD resolution. Furthermore, we can derive from previous question that 89% of all flat panel sets are HD ready. Moreover, we can see that full HD TV set with 26% share are already becoming significant.  The screen sizes are going to be bigger. Majority of the IPTV users own the screen larger than 32”. OptiBand Public 26 OptiBand Consortium
  27. 27. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010  The strong preference of HDMI shows good technical equipment of IPTV users. The scart connection between the TV set and STB was used only in 13%.  All connecting technologies provide sufficient resources for full HD video service. On the other hand domination of fixed Ethernet shows sufficient additional network resources for additional services.  Finally, the user perception of HD quality in comparison to SD significantly outperformed the SD service. Very satisfying is also the preference of HD IPTV service to HD satellite service. This may indicate that additional IPTV services provide significant usage advantage in compare to satellite HD service. TV consumption environment The emerging technologies and services described above do not significantly change the classical scenario of watching TV “on the couch”. While acknowledging the increasing parallel usage of multiple TV services in one household, the character of consuming HD TV services is therefore still best represented by a living- room environment. This is also because optimal viewing distance for screen sizes above 32” can be achieved in the most cases only in the (usually larger) living room. 2.5 Operator’s remarks The acceptance by an operator of the offered solution for a new functionality is not only a matter of cost vs. benefits ratio but also of the impact the deployment of that solution could have on its existing architecture. It is important for an operator that the inclusion of new functionalities in its platform does not significantly modify the existing architecture. This is mainly tied to its need to save the investment on existing resources. Examples of relevant investments devoted to the deployment of an IPTV platform are the live encoders, the STBs for their large number or the IP DSLAMs in the access network. The feasibility of a new solution results from its capability of fulfilling the following operator’s needs and interests:  It’s a common policy by the operators non to be tied to a single provider for the pieces of equipments they use in their deployments. For this reason the dropping equipment must have no dependencies from a specific existing element, for instance a specific brand of a DSLAM.  It’s important for an operator non to have to change its network engineering as far as possible, when new elements are added. Examples are the designed throughput of the links or the firmware of already presents other pieces of equipment.  The size of the investment and the scalability and legacy issues. For example, TI has almost 3000 IPTV DSLAMs all over the country, from at least three different manufacturers, and upgrading all those pieces of equipment would be a heavy job. The problem has been analyzed with reference to the network architecture for the IPTV service provided for by TelecomItalia, because it was the only one available, but it can be assumed that it represents a reliable reference approach for the operator’s point of view. TI had to deal with the same kind of problems when considered the inclusion of fast channel change or retransmission servers in its platform and in those cases the choice was always to put those servers in the PoP as the best tradeoff between efficiency and feasibility. With reference to the requirements defined in this deliverable, TI believes its duty to raise some points of attention coming from its experience on field in Italy: OptiBand Public 27 OptiBand Consortium
  28. 28. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010  The unicast video streams coming out from the OPTIBAND data dropping equipment at the EDGE device and addressed to each active STB linked to a DSLAM, whether data dropping was required or not, might heavily load the 1Gb access to that DSLAM. The new traffic size actually will depend on statistical factors (#subscribers per DSLAM, #IPTV subscribers, #HD users) but it could have heavy side effects on the performance of the link or require multiple input fibers to the DSLAM. Load tests are outside the scope of the project, but it would be important to consider this scalability issue too.  It is most unlikely that the interlaced formats will be fully replaced by progressive formats during the lifetime of the project. For this reason it is advisable that the deployed solution applies to both formats.  It is important that any encoded content (live or on demand) never uses more bandwidth than decided at design level to avoid loss of quality when the required bandwidth becomes higher than available on the link, with the unavoidable complaints by the subscriber. For this reason there is concern in using VBR rate mode; CBR or capped VBR would be preferred  At this moment the market of TV sets is ruled by LCD, but we observe a rapid growth with decreasing prices for Plasma sets in the consumer electronics market in Italy. For this reason we could consider the plasma TV sets also for the final testing phase. For completeness, we provide in the below table an indication of values of the encoding parameters, which photograph the setting currently in use in the TI IPTV service for HD live channels. Parameters H.264 HD Format Profile High@level 4.0 Video bitrate 7  8.5 Mbps Standard 1080i Horizontal Resolution 1920 Format Interlaced Frame rate 25 fps Aspect Ratio 16:9 Encryption All encrypted but promos GOP length 32 GOP structure IBBBP Open GOP YES Reference B Frames YES Scene Cut detection YES Deblocking Filter YES MCTF Filter YES PiP No Audio coding AC3 Audio bitrate 384 Kbps Sampling rate 48 KHz Resolution 16 bits Language 1 Italian OptiBand Public 28 OptiBand Consortium
  29. 29. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 Language 2 English Subtitles Teletext Mux bitrate 8.5  9.5 Mbps Video mode CBR Output IP multicast RTP NO FEC NO Stream format Transport Stream PSI tables PAT/PMT only TS packets 188 Bytes IP payload 7 TS packets The choice of the STB to be used during the development phases in the project is outside the role of the operator, but it would be an added value to demonstrate also that the algorithm works with the operator’s STBs in a free to air environment and simulating in the laboratory those features which hare actually dependent on the platform. 2.6 Definition of relevant use cases TI has been committed to manage the validation process of the implementations and integrations developed in the project with a test campaign in its laboratories (TILab). A specific Work Package is scheduled for this activity. The tasks of that WP are to define which tests are to be done, to run them and to analyze the test results. For the time being the project is only asked to decide which use cases are of interest and which are the success criteria for the project’s results 2.6.1 Typical scenarios The following suggests a possible set-up for the testing environment, which aims at complying with the criteria outlined in the above introduction. 1. We assume that:  The user is connected to the platform through an ADSL2+ line. The available downstream bandwidth is supposed at 15 Mbps.  The considered household has 3 active devices, connected to a single AG.  The household has 3 TV set: two of them are full HD with a monitor larger than 40”. The third TV set is a smaller LCD TV set HD ready at 32”  The household is watching a combination of HD channels, and HD VoDs.  The HD channels will be sport (preferably soccer) and or movies. The VoDs are movies.  Each encoded content will be composed of: o The video elementary stream encoded at 8 Mbps for each channel. o The audio elementary stream (2 audio channels encoded AC3 at 384 Kbps each). o No subtitles.  Dropping information from the original stream in the way established by the algorithm doesn’t significantly lower the perceived quality of the played audio and video. OptiBand Public 29 OptiBand Consortium
  30. 30. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 2. We assume that:  The user is connected to the platform through an ADSL2+ line. The available downstream bandwidth is supposed at 10 Mbps  The considered household has 2 active devices, connected to the AG.  The household has 2 TV sets full HD with a monitor larger than 40”.  The household is watching an HD channels and an HD VoD.  The HD channel will be sport (preferably soccer).  Each encoded content will be composed of: o The video elementary stream encoded at 8 Mbps for each content. o The audio elementary stream (2 audio channels encoded AC3 at 384 Kbps each). o No subtitles.  Dropping information from the original stream in the way established by the algorithm doesn’t significantly lower the perceived quality of the played audio and video. All of the previous elements can be modified, added, removed to test different user environments. The above use cases shall be also used to check the right behaviour of the dropping solution even in case of free to air channels or when changing some elements in the IPTV chain (e.g. the STB). 2.6.2 Specification of OptiBand user testing setup Based on the background information presented in section ‎ .4.3, the following specifications for the 2 OptiBand user testing setup have been made. These encompass the user characteristics, TV services, content, end-user equipment, and the TV consumption environment. User characteristics  To reflect the broad user group, the sample should be balanced in terms of demographic variables (most importantly age, gender, and professional status).  The number of subjects in a viewing test should be from 15 to 40: 15 is the absolute minimum for statistical reasons, while there is rarely any point in going beyond 40.  The test subjects should not be directly involved in video or picture quality evaluation as part of their work and should not be experienced assessors.  The test subjects should have normal visual acuity.  The test sample should be coming from a country that is representative for the European market landscape (see also below). In this regard, Austria (Vienna) and Italy (Torino) are very suitable countries for conduction of QoE studies, because they represent the viewing groups with maximum and minimum average TV viewing times. Furthermore, the Austrian and Italian TV service distribution is representative for the European market landscape. o The average viewing time of the Austrian test sample should be approximately 148 minutes. o The average viewing time of the Italian test sample should be approximately 234 minutes. The test subjects should be questioned about type of used TV services in living room (e.g. IPTV, Satellite, DVB-T ...). TV services  In order to be representative, the technical OptiBand TV service setup (e.g., codec settings) should be consistent to typical HD IPTV services (e.g. Telecom Italia, see the detailed specifications in section 3.4.3 Technology requirements). OptiBand Public 30 OptiBand Consortium
  31. 31. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010  Since the user’s expectations are important for subjective quality judgments, the users will be provided with initial scenario briefings which indicate that their test service is a paid TV service package from a certain provider (including fees per month, contract duration, etc.). In order to reflect the above described TV service landscape, and to investigate possible differences with respect to quality expectations, the scenarios used in the OptiBand QoE tests should represent both Live TV and VOD services. For example, an introductory briefing of the Live TV scenario would inform the user that the viewed content is live broadcast. By contrary, in the VOD scenario the user would be asked to imagine that he/she had chosen the test sequence from a VOD library. Content  The length of investigated video sequences is given by ITU-R BT.500-11.  In order to reflect content popularity, the OptiBand test bed should be mainly based on the following content classes: o Soccer - this CC contains wide angle camera sequences with uniform camera movement (panning). The camera is tracking small rapid moving objects (ball, players) on the uniformly colored (typically green) background. o Action movie - The content class contains a lot of global and local motion or fast scene changes. End-user equipment Based on the above presented results, we can conclude that most of IPTV users are already very well equipped and ready for HD quality services. Therefore, the following properties of the end-user devices should be as follows:  Considering the market situation, the TV set should be flat panel, preferably LCD or OLED (not Plasma, due their lower market share). They should be based on CRT technology or projector setups.  The resolution of the TV set must be full HD.  The screen size should be 32 -42”.  The video content will be provided to the TV with an HDMI interface (see specifications in D2.1). TV consumption environment Therefore, we recommend emulating “couch-based” living-room conditions in a lab setting, as defined in ITU- R BT.500-11 (see D.2.1 for further detail). The general viewing conditions for subjective assessments in home environment are defined by ITU-R BT.500-11. The monitor resolution should be 1920 x 1080 pixels. Furthermore, the monitor peak resolution should be above 200 cd/m2 and environment luminance on the screen below 200 lux. The viewing distance should be set with respect to screen size. Finally the flat panel brightness and contrast should follow the ITU-R BT.818 and ITU-R BT.815. 2.6.3 Success criteria Even if the goal of the project is primarily to develop a proof of concept of the dropping algorithm, in would be a value added to prototype a solution applicable in concrete actual IPTV “ecosystems”. Bearing that in mind, the success criteria to evaluate the project’s results are two-fold: OptiBand Public 31 OptiBand Consortium
  32. 32. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010  Dropping information from the original stream in the way established by the algorithm doesn’t significantly lower the perceived quality of the played audio and video. Objective metrics (such as SSIM) will be used for objective measure of success. However, subjective metrics will be selected in order to complement the objective metrics and provide subjective perspective about the effectiveness of the algorithm. The evaluation of the perceived quality can be understood either as the quality as perceived by the user who is watching the content on his TV set after decoding by the STB or the quality at the output of the dropping equipment. In the first case the evaluated quality is actually the result of the behaviour of a chain of elements (the encoder + the dropping equipment + the decoder in the STB + the scaler in the STB and/or in the TV set) each of which has its own performance and quality. In the second case, the observer has to put himself at the output of the dropping equipment (it is just a MPEG TS stream) capture the stream and display it against the original one in input to the dropping equipment. This second approach is the way TI currently uses when evaluating the encoders.  The developed solution is applicable to existing IPTV platforms and environments. This means that the developed components could be usable in configurations like the followings: o An existing headend where a set of HD encoder is already installed o Different STBs, from different manufacturers, with different SoC and DRM clients. o Different home network settings, including the case where there is a WiFi bridge between the AG and the STB. Packet Dropping solutions not yet supported by the current IPTV systems (STBs), such as using the Scalable Video Coding, are dedicated to future generation of IPTV platforms and environments. For that, only a “Proof of Concept” will be the output of the project. OptiBand Public 32 OptiBand Consortium
  33. 33. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 3. Conclusions This deliverable is the output of the activity performed in WP1 of the OPTIBAND project. The job in WP1 included collection and integration of requirements on business and technological aspects and user perspectives to build the functional specifications of the content aware data drop algorithm. It was decided to consider HD live and on demand contents and attention is paid to them only, even if the IPTV service will continue to include distribution of both SD and HD contents during the years of life of the project. The choice derives from the forecast of a growing request for HD contents, a large diffusion of full-HD TV sets and the marketing trend to offer premium contents mainly in HD. It is worth reminding that the service will still be a mix of contents in SD and HD during the life time of the project. There is a chance that the availability of 1080p will grow in time: many TV monitors already support it, Blu- ray discs can be played in that format, …etc. For these reasons it would be advisable that the deployment of the dropping algorithm will work with both formats, progressive and interlaced. New layered coding technologies are all far from deployment (mainly owing to the lack of SoC to build new STBs). Among them only SVC and MVC are worth considering as long term solutions and will be investigated by the project (see deliverable D3.1 for details). The considered encoding technology is H.264/AVC for supporting current STBs in usage and scalable extension of H.264/AVC (SVC) for future generations of IPTV system and STBs. The most relevant encoding parameters are the choice of the H.264 Profile @level, the format, the mux, the elementary stream rate mode and bitrate for video and the encoding technology and bitrate for audio. Nowadays a good QoE is achieved even for challenging contents (soccer, action movies, ..) with a video bitrate of 8 Mbpsin case of 1080i format; we can expect that the same quality will be achieved using 6 Mbps by the end of the project. Higher bitrates are required when the 1080p format is preferred. The encoding parameters for VoD contents are the same as in the live case Both live and on demand contents are encrypted. It is up to the partners involved in the development of the solution to integrate the content protection client in the selected STBs. The choice of the STB to be used during the development phases in the project is outside the role of the operator, but it would be an added value to demonstrate also that the algorithm works with the operator’s STBs. Information about the current state of a STB can be gathered partially from the databases in the middleware but partially should come from the CPE and/or the STB itself. The standards developed by the DSL Forum (TR-XXX) proved to be heavy and redundant. Further they are not thought to provide information in real time. The project should find a different suitable way to get information about the free bandwidth on the DSL line non to be forced to rely only on static information about the STB and dynamic information about what it is playing, nothing about the current DSL rate. The most critical choice to be addressed in designing the network architecture for an IPTV solution which includes the OPTIBAND data dropping functionality is the location of the dropping equipment in case of live contents. The project selected as a possible solution to implement the Packet-Drop algorithm (PDA) at the Edge device. Edge device is the network element located at the metro-access edge; it aggregates many DSLAMs access devices and connects them to the Metro area. Implementing the PDA at the Edge device has implications on the control plane (signalling protocols) and data-plane (mainly on Layer2).The approach implies that the Packet-Drop Device (PDD) is required to personalize the multicast channels and actually generate an unicast video stream per STB. The Layer-2 MAC is replaced by the PDD from multicast MAC to unicast MAC per destination STB. The PDD performs the MAC replacement for each STB, A DSLAM that receives a video channel from the Edge device, with IP-Multicast over MAC-Unicast will use its Layer-2 MAC table to perform the forwarding decisions of the channel’s packets to the specific user’s STB based on the destination unicast MAC address value. The STB that receives the multicast IP channel, over unicast MAC address will pick up the packets and will decode the video content and will present it at the appropriate channel according to the IP-Multicast address. OptiBand Public 33 OptiBand Consortium
  34. 34. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 A second target WP1 was to define typical use cases, which are typical scenarios that are characteristics of the operation of the system. For each use case, success criteria have been defined, which will be verified during the demonstration. TI has been committed to manage the validation process of the implementations and integrations developed in the project with a test campaign in its laboratories (TILab). A specific Work Package is scheduled for this activity. The tasks of that WP are to define which tests are to be done, to run them and to analyze the test results. For the time being this WP is only asked to decide which use cases are of interest and which are the success criteria for the project’s results The selected use cases are simply those already assumed in the Technical Annex document of the project. The OptiBand user testing setup will be based on the following decisions:  content classes: o Soccer - this CC contains wide angle camera sequences with uniform camera movement (panning). The camera is tracking small rapid moving objects (ball, players) on the uniformly colored (typically green) background. o Action movie - The content class contains a lot of global and local motion or fast scene changes.  The TV set should bet flat panel, preferably LCD or OLED.  The resolution of the TV set must be full HD.  The screen size should be 32 -42”.  The video content will be provided to the TV with an HDMI interface. Even if the goal of the project is primarily to develop a proof of concept of the dropping algorithm, it would be an added value to prototype a solution applicable in concrete actual IPTV “ecosystems”. Bearing that in mind, the success criteria to evaluate the project’s results are two-fold:  Dropping information from the original stream in the way established by the algorithm doesn’t significantly lower the perceived quality of the played audio and video. Objective metrics (such as SSIM) will be used for objective measure of success. However, subjective metrics will be selected in order to complement the objective metrics and provide a subjective perspective about the effectiveness of the algorithm.  The developed solution is applicable to existing IPTV platforms and environments. This means that the developed components could be usable in configurations like the followings: o An existing headend where a set of HD encoder is already installed o Different STBs, from different manufacturers, with different SoC and DRM clients. o Different home network settings, including the case where there is a WiFi bridge between the AG and the STB. OptiBand Public 34 OptiBand Consortium
  35. 35. D.1.1 - FUNCTIONAL SPECIFICATION DOCUMENT OPTIBAND 248495 12/05/2010 4. Bibliography [1] BIGresearch, “Pay TV Industry Demographic Profile,” BIGresearch CIA, Oct. 2009, available at: http://www.valassis.com/1024/resources/TELE_demo.aspx. [2] European audiovisual observatory, “Yearbook 2009 - Film, television and video in Europe,” European commission, 2010. [3] R. Jain, “Quality of Experience,” IEEE Multimedia. Volume 11, Issue 1, 2004, 96–95. [4] Ref. to ACE framework [5] Olswang, “Olswang Convergence Consumer Survey 2007,” Nov. 2007. [6] Deloitte, “Media prediction TMT trends 2008,” 2008. [7] European audiovisual observatory, “Yearbook 2006 - Film, television and video in Europe,” European commision [8] List of most-watched television broadcasts, available at: http://en.wikipedia.org/wiki/List_of_most- watched_television_broadcasts. [9] Parks Associates Industry Reports, “FEATURED IN: Converge! Network Digest/Blueprint: Telco Triple Play,” 2003, available at: http://www.parksassociates.com/press/articles/2003/converge_mg.htm. [10] Informa Telecoms & Media, “Broadband and IPTV market status 2007,” 2007. [11] S. Wolf, M. Pinson, “Application of the NTIA general video quality metric (VQM) to HDTV quality monitoring,” Proceedings of The Third International Workshop on Video Processing and Quality Metrics for Consumer Electronics (VPQM), Scottsdale, AZ, USA, January 2007. [12] Emil Dumic, Sonja Grgic, Mislav Grgic, “Comparison of HDTV formats using objective video quality measures,” Journal of Multimedia Tools and Applications, Springer Netherlands, Jan. 2010. [13] A. Raake, M.N. Garcia, S.Moeller, J. Berger, F. Kling, P. List, J. Johann, and C. Heidemann, “T-V- MODEL: Parameter-based prediction of IPTV quality,” in ICASSP08, in process, 2008. [14] M. Ries, C. Crespi, O. Nemethova, and M. Rupp, “Content-based Video Quality Estimation for H.264/AVC Video Streaming,” in IEEE Wireless Communications and Networking Conference, 2007. [15] A. Raake, M.N. Garcia, “Towards content-related features for parametric video quality prediction of IPTV services,” in Proc. of ICASSP 2008.. [16] Bradley, Nigel, “Marketing Research. Tools and Techniques.” Oxford University Press, Oxford, 2007 ISBN 0-19-928196-3 ISBN 978-0-19-928196-1. [17] Quarterly Global TV Shipment and Forecast Report, available at: http://www.displaysearch.com/cps/rde/xchg/displaysearch/hs.xsl/quarterly_global_tv_shipment_an d_forecast_report.asp [18] LCD TVs to Exceed 180 Million Units in 2010, available at: http://www.displaysearch.com/cps/rde/xchg/displaysearch/hs.xsl/01_27_09_displaysearch_sees_fl at_panel_display_growth_slowing_through_2015.asp [19] List of most-watched television broadcasts, available at: http://en.wikipedia.org/wiki/List_of_most- watched_television_broadcasts. [20] ITU-R Recommendation BT.500,”Methodology for the subjective assessment of the quality of television pictures,” International Telecommunication Union, 2002. OptiBand Public 35 OptiBand Consortium

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