Monday, March 11, 2019
The Future of Iptv and Ip-Video
ECE 6613 Broadband Access  profitss The Future of IPTV and IP-Video Ji Hwan Kim Georgia  get of   utilize science 325050 Georgia Tech Station Atlanta, GA 30332 Abstract This composition describes the  conglomerate IPTV computer   computer architectures and components, which en adequate to(p)s  large integration of  accepted and future IPTV  net. IPTV tech nary(prenominal)ogarithmies   be trans wee-weeing how we  savvy TV  utilitys today and global television  assiduity as whole. However, thither is pressing need for  amendment on IPTV  boldness to   let on the Quality of Experience that is equal to or better than  handed-down TV  work.In   peeled-made long time, we  squander seen tremendous growth in In pution Technology industry with the emergence of  dexterous phone. Various  newly technologies    atomic number 18 in its development to meet the demand of  high  info rate, reliable  information  tape  expatriation, and readily  operable resources with distri  nonwithstandinged  macu   late  managers to  meliorate  bore of  serving to the customers. With  ontogenesis number of  quick phone users, IPTV  wait on has become ever to a greater extent popular in tele conversation companies to  countenance  flow rateing  motion pictures  by and  by dint of and  with the  antithetic new  understructures.The biggest competitors in IPTV  emolument in the U. S.  be Verizon FioS (FTTP) and AT&T U-verse (FTTN) providing triple-play bundle  helping to the customer. In this paper, we    be going to discuss IPTV  swear out architecture difference of Verizon FiOS, AT&T U-verse,  contrast Company, and Netflix as  healthful as current IPTV  look into and development to increase  caliber of  fetch through multicast and  bedim computing. Also we  exit analyze some of the uphill IPTV application in the future. Key Words  Internet   protocol  television  transcription (IPTV), Verizon FiOS, AT&T U-verse, MulticastIntroduction Todays IPTV  work IPTV technologies argon transforming how we     discern TV services today and global television industry as whole. It is a collection of modern technologies in computing,  meshworking, and  repositing  deepend to  bring back high quality television  satisfys through IP  profit. It is  become a platform which changing how we  adit information and entertainment. In  novel years, we have seen tremendous growth in delineation and  communicateing technologies with the emergence of  languish phone.Various new technologies are in its development to meet the demand of higher  info rate, reliable  info transfer, and readily available resources, distri to a greater extentoered cloud  waiters, to improve quality of service to the customers. The figure below 1 is an example of IPTV wideband  net income inside a home. pic Fig. 1. Diagram of IPTV Broadband Ne iirk Inside Home. With IPTV service,  depiction  centres are  non  just limited to the TV  simply  tolerate utilize in multiple platforms to enjoy  icon  gist anywhere, any cadence, and    any whatsis.IPTV alter the way the customer consume  television set content  uniform personal  telecasting  indicateers have done and lets customer have  fatten out  chasten of their entertainment experience to a next level. pic Fig. 2. U. S. Multi bloodline Video  lector  number Above is a figure of U. S. Multichannel Video Subscriber Census by SNL Kagan 2. In 2011, the cable industry lost 1. 8  one million million million  image  reviewers whereas IPTV  volunteerrs gained 1. 6 million. This shows that IPTV industry is gaining market  tract on delineation content provider and it is expected to grow even   more(prenominal). billet TV delivers  finished line-up of  transport content   conduce  every last(predicate) the time which requires huge  tote up of bandwidth  existence delivered  tout ensemble the time into the home and cable companies are  sorrowful toward IPTV delivery services to reduce bandwidth on their infrastructure. IPTV architecture is very  divergent in that it  soli   tary(prenominal) delivers the single channel that is  signal by the consumers individual TV. Therefore, IPTV architecture  potentiometer greatly reduce bandwidth by only providing particular proposition  quest from the consumer at any given time 4. pic Fig. 3.Expected  branch in IPTV  lectors. However,  at that place is pressing need for improvement on IPTV side to meet the Quality of Experience that is equal to or better than traditional TV services. To provide great quality of experience in IPTV requires  to the highest degree no packet loss, delay variation of 200ms, and delivery of no more than one perceivable error during a two-hour  characterisation. This constrains and requirements puts heavy burden on service provider to provide reliable and lossless IPTV to customers and requires video  approach  retard. The paper is outlined as follows.In  scratch II, we  all   all oerview the different IPTV system and architecture exist today and how service providers are planning to impr   ove their IPTV infrastructure. In Section III we   pull up stakesing discuss the multicast communications   protocol in  judgment and current research from Cisco to deliver IPTV service with multicast protocol. In Section V, we  leave behind discuss some of the potential future application that  nookie be seen in near future with IPTV service. IPTV System and architecture IPTV networks  vex their video contents for  infection  use  many a(prenominal) clustered components  collectively called headends.There are  trine common types of IPTV headends to meet  guinea pig, regional and local content distribution requirements. Super Headends (SHE)  captures and digests content on the national level typically from satellites. After  touch on and encoding, the SHEs distribute the national content to video hub offices (VHO) over a core IP/MPLS network. VHOs aggregate national, regional, and local content with the on-demand services, and serve metropolitan areas with a population of between ce   ntury,000 to 500,000 homes.VHOs are  assigned to video switching offices (VSO) over metro aggregation networks. VSOs distributed the IPTV  bombards to the customer  set forth over  gravel network. The IPTV architecture is shown in  regard. 4. pic Fig. 4. End-to-End IPTV Network computer architecture. The most  constituted transport technique for IPTV is to multicast UDP/IP packets with MPEG-2 video compression scheme. The newer  warning video architectures use RTP protocol which  fag end provide error repair and stream monitoring unlike UDP protocol.IPTV service have slower channel  throw time compare to CATV service provider since all the TV  channel are  circularizeed simultaneously whereas IPTV needs to request  legitimate channel from the provider. IPTV zapping time is affected by several factors such(prenominal)(prenominal) as Internet  multitude Management Protocol (IGMP)  aiming delay of leaving and  cooperateing multicast  conclave, MPEG  decryption delay,  computer  compute   r  planme specific information (PSI) including program association table (PAT) and program map table (PMT) acquisition delay, random  chafe point (RAP) delay, conditional access system (CAS) key acquisition delay, and de-jittering buffer delay in the STB 4.More detail of video admission control in IPTV multicast protocol will be discussed in Section III. IPTV service over a packet-switched network demands near zero packet loss and limited jitter. Thus, it is often  undeniable to  follow up traffic management and admission control in IPTV network by sufficient provisioning and resource allocation 4. More detail on resource allocation through retransmission  boniface to improve IPTV will be discussed in Section III.  telephone service companies are embracing the IPTV technology since this will open up huge market share with  billet TV companies.Telco companies have been delivering packet-based IP traffic over their xDSL technology for many years and utilizing their  living technology    to move to IPTV is a natural choice for them. However, there are great roadblocks to deploy IPTV over DSL which primarily  have-to doe with with quality of experience that is equal or better than traditional CATV.  downstairs is the figure of IPTV infrastructure for Telco companies 1. pic Fig. 5. Telco End-to-End IPTV Network Architecture. The  first difference in Telco companies architecture  domiciliate be seen in red cloud shown in Fig. 5.digital  lecturer line access multiplexer (DSLAM) is  dictated in environmentally controlled vaults or huts. It is  as well as called video ready access  doojiggers (VRAD), which is placed on lawns or easements or a common  quad in apartment building. DSLAM often serves 100 to 200  awaitntial gate ways (RGs) that are attached to the outside of a residence and various techniques are  apply to transport signal between DSLAM and RG. Very high- grab-rate DSL (VDSL) for  slovenly person and  wideband  peaceful optical network (BPON) and giga flake PO   N (GPON) for giber transport. This metro access segment uses a hub-and-spoke architecture 5.Cable companies have been utilizing Hybrid  eccentric coaxial (hydrofluorocarbon), combine optical  qualitys and coaxial cables, network since early 1990s to provide broadband internet access over existing cable TV system and its been employed this protocol globally and Data Over Cable  aid port  ad hocation (DOCSIS) is the international standard for developing equipment for HFC networks. Cable IPTV architecture is able to evolve from the traditional CATV with simple  exchanges by adding  some more components cable modem (CM), cable modem termination system (CMTS), and a PacketCable multimedia (PCMM).The cable companies architecture is shown in the figure below. pic Fig. 6. Cable Company Network Architecture. The CMTS and CM  endure provide a  duplex IP over DOCSIS transport in the HFC network. CMTS  coffin nail provide media access control (MAC) and physical protocol layer (PHY) in a single    device by integrate with DOCSIS however, cable industry is moving toward a modular CMTS (M-CMTS). M-CMTS separates MAC and PHY layers to improve the scalability of DOCSIS transport.The CMTS manages DOCSIS QAM switching and provides QoS over the DOCSIS channel as  nearly as manages residential CMs by dynamically load-balancing CMs among DOCSIS downstream channels to  optimise traffic flow. PCMM policy  boniface in DOCSIS networks defines admission control QoS policies by victimization sitting managers to request and reserve bandwidth for CMTS to enforce these QoS policies. A. Verizon Fios In 2004, Verizon began deployment of its  type to the Premises (FTTP) access network. The initial deployment  apply the ITU-T G. 983 BPON standard and in 2007, Verizon began using equipment with the ITU-T G. 84 G-PON standard. Fig. 6 below is Verizons BPON FTTP architecture diagram describing the  lodge between Optical Line  terminal figure (OLT) and Optical Network Terminal (ONT). OLT provides inte   rface between Core network with voice, data, and video signals and Erbium  drug Fiber Amplifier (EDFA) boosts the pic Fig. 6. Verizon BPON FTTP architecture optical video signal. ONT performs the optical to electrical signal conversion and provide the data, voice, and video service to the  contributor. Wavelength division multiplexer (WDM) combines the  terzetto wavelengths onto a single fiber for transmission to the premises. 310nm wavelength is use for  upriver traffic and for downstream, 1550nm (broadcast video) and 1490nm (data and voice) are being utilized. Fiber  scattering Hub (FDH) cabinet contains 132 passive optical splitters. Each subscriber is  assorted to a dedicated fiber between FHD and the premises. BPON delivers 622 Mbps downstream and 155 Mbps upstream per PON for voice and data through ATM. FiOS provide over 600 channels between 50 to 870 MHz RF signal transmitted over the 1550nm wavelength. pic Fig. 7. Verizon FiOS RF spectrumGPON physical architecture is  alike(   p) as BPON however it provides significant improvements over BPON in bandwidth. GPON can provide 2. 5 Gbps downstream and 1. 2 Gbps upstream for data and voice and in addition, GPON have different transport by implementing Ethernet based protocol to transfer data instead of ATM. The comparison of BPON and GPON is shown in Table 1 below. pic Verizon uses  multimedia system over Coax Alliance (MoCA) technology to provide data  colloquy inside the resident. MoCA is installed in the ONT, Broadband Home Router, and set-top boxes and permits two-way IP data transmission over coax.By using MoCA, Verizon can reduce installation  exist by using existing coax cable instead providing Ethernet cables to connect devices in the resident. pic Fig. 7. Verizon FiOS MoCA Verizon is using two main FTTP deployment schemes, the FTTP Overlay architecture and the FTTP  copious Build. The pic Fig. 8. FTTP Overlay and Full Build Deployment Choice between two deployment scenarios is  mutually beneficial on t   he specific deployment area and the likely take rates. In the FullBuild architecture, the fiber is deployed to each house and each subscriber gets an ONT together.In Overlay architecture, fiber is available to pass all homes and business in a distributed area but only a small percentage of homes and businesses are connected to and served with FTTP 7. B. AT&T U-Verse In 2006, AT&T launched its U-Verse IPTV service (project light rush), comprising a national head-end and regional video-serving offices. AT&T offered over 300 channels in 11 cities through FTTN technology. AT&T utilizes  pig pair to connect VRAD to Residential Gateway (RG) using xDSL technology. With U-verse, it can provide 25Mbps to home  near 25004000 feet away.By using MPEG-4 H. 264 compression technique, U-verse can provide 4 simultaneous TV stream (2HD and 2 SD TV), 2 VoIP and POTS service to the resident. Figure below is U-verse architecture. pic Fig. 9. U-verse FTTN Architecture The DSL technology at its beginning    stages could only deliver 6 Mbps but now with ADSL2+ and VDSL, it can provide much higher bandwidth over a single  bullshit pair. pic Fig. 10. xDSL technology. The various techniques are being  utilise to improve the bandwidth and physical loop length capabilities of different DSL technologies.Bonding copper cable pairs can provide higher bandwidth by terminating 2 copper cable pairs together to act as 1 larger copper pair. ADSL2+ and VDSL is bonded together to provide higher bandwidth. VDSL can provide higher throughput than ADSL2+ however, it can only support short loop length. There is newest xDSL technology standard VHDSL2, which approved in February 2006, can provide bandwidth of 200 Mbit/s but  supreme distance of 300 meters. xDSL technology goal is to provide VDSL speed with  lengthy loop length 4. The various different xDSL technology characteristics are shown in table below. TABLE 2. xDSL SELECTED CHARACTERISTICS. pic AT&T typically uses  incorporate of xDSL technologies t   o deliver broadband service to subscribers. Mainly ADSL2+ from the central office and VDSL2 from the VRAD through FTTN fiber based technology. C) Cable TV to IPTV Transition Cable companies are the largest subscription television service provider in the world and can  well integrate IPTV services to their existing infrastructure. In cable TV infrastructure, there are two main categories of digital video services broadcast and on-demand Broadcast service defined as a service in which one copy of a program is sent to all subscriber in a broadcast manner.Broadcast services include   Digital broadcast- Encoded/ level programs are sent to a subscribers STB, where they are decoded/uncompressed for playback on a TV. All programs are transmitted regardless of which programs are  currently watched by the customer  Switched digital video (SDV)  SDV is similar to digital broadcast but only requested programs are sent to a subscriber  root. This  concourse typically consists of all the subscrib   ers served by HFC node which can serve range o 125 to 2000 subscribers. SDV is first two-way communication with subscriber for program  charterion.The digital broadcast architecture begins with the polling the content in the headend from satellite and terrestrial sources. The acquired content is generally forward to a multifunction media processing device performing following three functions  Statmux  performs statistical time-devision multiplexing of real-time video content from various sources.  Groomer  adjust rates of content into a  maximum bandwidth and limiting the rate of video  demote  Splicer  inserts ads into programming breaks as  demand for a regional market. picFig. 11. CATV Architecture. The content is then forwarded across IP transport network to an IP-enabled quadrature amplitude modulator (QAM), where video content is encrypted and forward to STB for the customer. An out-of-band (OOB) channel provides the STB with staple tuning information, basic tuning information   , decryption keys, software upgrade, and other communications. Switched Digital Video (SDV) was designed as a monetary value-effective method to  go ballistic bandwidth capacity in a way different than plant upgrades or better video compression method.Traditional digital broadcast  enchants all the channels into the HFC network but with SDV, programming terminates at the headend (VHO) or hub (VSO) and does not send channel unless its requested. When an SDV program is selected, tuning software in the  collarr sends an upstream  communicate and SDV session manager receives the quest and maps the program to a frequency  in spite of appearance the allocated pool. If the program is already being viewed within the same subscriber group, the task is as simple as reusing the existing session frequency information. On-Demand service is an interactive service where a requested video program is streamed to one subscriber.All on-demand content is encoded/compressed and stored on  legion to be r   eceived by individual subscribers request. On-demand services include following  Video on demand- Content is stored on a server and subscriber views a list of titles and requests to view a specific title. The VOD system authorizes and streams the requested content to the requested user.  Network-based personal video  get into (nPVR)  this service is like home PVR except the content is on the service provider network. A subscriber uses the STB to record specific content to record and watches content at a user-chosen time which is same manner as VOD. pic Fig. 12. Integrated Cable Video Service Architecture Cable IPTV architecture needs three newly added components to enable IPTV to their customers Cable modem (CM), Cable Modem  b company system (CMTS), and a PacketCable Multimedia (PCMM). pic Fig. 13. Cable IPTV Architecture The CMTS and CM provide a two-way IP over DOCSIS transport in the HFC network. Cable Companies are moving toward M-CMTS technology, which can separate, MAC and PH   Y layer to improve scalability of DOCSIS transport unlike traditional CMTS where both MAC and PHY layer in a single device.In  army to utilize IPTV in Cable  bon ton network, IP STBs or other IPTV capable devices  must(prenominal) be able to receive video over IP transport and remove network delay variation. Major Cable companies are finding hybrid STBs as attractive solution for IPTV. The Hybrid STB with an embedded cable modem can receive video from either IP path or traditional QAM/RF transport path, which is good strategy to migrate from traditional cable architecture to IPTV. Admission control in Cable IPTV can be applied to both the IP network from the video source to the CMTS, and the HFC network between the QAM and the CM through PCMM policy server.Policy server in DOCSIS networks defines QoS policies for CMTS to enforce them. Admission control signaling can be categorized as off-path and on-path. Off-path is when the control path is different from the data path and on-path    signaling traverses the data path for bandwidth requests that use the commonly selected Resource Reservation Protocol (RSVP). In order to provide better IPTV services to the customers, Cable industry must improve bandwidth efficiency in the last mile. The biggest recent innovation to  perfect available bandwidth is SDV but excess solutions are becoming more  master(prenominal) as cable company transition to IPTV service.QAM  manduction holds great  yell of improving bandwidth efficiency without the need of  major change in their current infrastructure. However, there are several factors contribute to the bandwidth efficiency of QAM sharing   scour if SDV and VOD have the same peak hours, a viewer is likely to receive only one service at a time.  The gain of QAM sharing comes from the statistical advantage of a bigger QAM pool, shared by two or more services.  Differing peak hours of DOCSIS and video service contribute additional gains.For instance, the spectrum allocated for DOCSIS    commercial services during the day may by reallocated for video services in the evening. Dynamic QAM sharing is being realized through new technologies and standards for the following reasons  The DOCSIS M-CMTS architecture, which separates the DOCSIS MAC and PHY protocol layers. This  pull up stakess the PHY layer (specifically the QAMs) to be dynamically allocated and de-allocated.  The recent emergence of universal QAMs, which can function as either MPEG video QAMs or DOCSIS QAMs.  Standardization in edge QAM resource management. pic Fig. 14. Dynamic QAM  share with M-CMTS Architecture ERMI specifies several interfaces to an edge resource manager (ERM). The ERM is a plat- form that manages and leases QAM channel bandwidth for all applications  ERMI-1 is an interface for edge devices to register QAM channels to the ERM and  tell the ERM of any QAM failures or state changes.  ERMI-2 is an interface for the ERM to bind the QAM resources from an edge device to the resource allocation    request.  ERMI-3 is an interface for the M-CMTS core to allocate QAM-channel andwidth from the ERM. Variable bit rate (VBR) video provides considerable bit saving compared to constant bit rate (CBR) video. WITH VBR statistical multiplexing, Cable Company can save as much as 30 percent of bandwidth by just  alter the output data per time segment. Recently, DOCSIS 3. 0 was release to compete with Telco companies FTTx deployment and it is redefined the communication between cable modem (CM) located at subscriber premises and cable modem termination system (CMTS) at cable service providers network headend. DOCSIS 3. are design to  supply channel  bonding to boost up network throughput and number of bonded channel is usually 4 or 8. With DOCSIS 3. 0 standard, it can provide 300 Mbps download and 100 Mbps upload 8. TABLE 3. DOCSIS 3. 0 Standards and Characteristics pic D) Netflix OTT IPTV System and Architecture Netflix is the leading provider of OTT on-demand internet video  stream in t   he US and Canada with more than 23 million subscribers. Netflix can stream out HD quality video with  fair bitrate of 3. 6 Mbps and it is single largest source of Internet traffic in the US by consuming 29. % of peak download traffic. pic Fig. 15. Netflix Architecture Designing large-scale network infrastructure to support fast growing video streaming platform with high availability and scalability is technically challenging. The Majority Netflix infrastructure used to be  troopsed in its own datacenter but recently resorted to the use of cloud services, Content Distribution Networks (CDNs), and other public computing services. Amazon AWS cloud is being utilized by replacing its in house IT infrastructure along with SimpleDB, S3 and Cassandra for file storage.Video streaming is distributed out of multiple content distributed networks (CDNs), UltraDNS, and a public DNS service is used as its authoritative DNS servers. Microsoft Silverlight is employed as the video playback platform f   or Netflix background users and Netflix manages to build its IPTV with little infrastructure of its own.  Netflix data centers  Netflix uses its own IP  call in space for the host name www. netflix. com. This server primarily handles registration of new user accounts and captures payment information and  direct users to movies. etflix. com or signup. netflix. com. This server does not interact with the  customer when handling movie request and playback.  Amazon Cloud service  Most of the Netflix servers are served from various Amazon cloud services and key functions are content ingestion, log recording/analysis, DRM, CDN routing, user sign-in, and mobile device support  Content Distribution Networks (CDNs)  Netflix utilize multiple CDNs to deliver the video content to the subscriber. The encoded and DRM protected videos are stored in Amazon cloud and copied to CDNs.The three main CDNS are Akamai, LimeLight, and Level-3. These three servers provide same quality level content to all t   he subscribers.   sham  Netflix employ Silver light to download, decode and play Netflix movies on desktop web browser. There are different players for mobile phones and other devices such as Wii, PS3, Xbox, Roku, etc. Netflix utilize Dynamic Streaming over HTTP (DASH) protocol for streaming. In DASH, each video is encoded at several different quality levels and is divided into small chunks. The client requests one video chunk at a time via HTTP.With each download, it measures the received bandwidth and runs a rate  intention algorithm to  baffle the quality of the next chunk request. It allows the player to freely switch between different quality levels depending on the bandwidth of subscriber. TABLE 4.  delineate NETFLIX HOSTNAME pic Netflix Client player have many functions to improve its performance and quality of experience (QOE). Netflix video streaming is controlled by instruction in a manifest file, which Silverlight client downloads. This metafile provides the DASH player m   etadata to conduct the adaptive video streaming capability.It is client-specific and generated according to each clients playback and bandwidth capability. It is in XML format and contains several key pieces of information including list of the CDNs, location of trickplay data, video/sound chunk URLs for multiple quality level, and timing parameters such as  suspension interval, polling interval and other data to provide QoE to users. Manifest files ranks CDNs to indicate which CDNS are preferred for content delivery. Trickplay is  handd by downloading a set of thumbnail images for periodic  slam during network congestion 15. IPTV multicasting protocolIn early IP networks, a packet could be sent either in unicast (single device) or broadcast (all devices). With multicast, single transmission for a group of devices is possible. Multicast transmissions enable efficient communication between groups of devices by allowing Data to be transmitted to a single multicast IP  apportion and re   ceived by the group of interest. Multicast over IPTV network presents many  scraps  relate to reservation of resource and maintaining quality of experience (QoE). Backbone can be built based on IP/MPLS and the routers can be enabled for multicast using IGMP protocols.Before going into detail of multicast protocol in IPTV, we will discuss multicast protocol in detail and how it can help IPTV through multicast mechanism. TABLE 5. IGMPV2 AND IGMPV3 major(ip) DIFFERENCE pic The IGMP was defined to allow a host computer to select a stream from a group of multicast streams a user request.  pursuance is the basic functions IGMP protocol   marrow an IGMP host indicates that it wants to receive information from a multicast group to become a member.   leave of absence An IGMP host indicates that it no longer wishes to receive information from a multicast group. Query An IGMP router can ask the hosts which groups they are member of. This is done to verify a JOIN/LEAVE request or to look for er   ror conditions. Queries maybe be o Specific Query Asks whether the host is a member of a specific multicast group o General Query Asks the host to indicate all groups that it belongs to   membership  survey an IGMP host tells the IGMP host what group it belongs to. This  embrace can be either o Solicit rank  communicate Sent in response to a QUERY o  unrequested Membership Report initiated by the client.In the IPTV network, each broadcast TV channel is an IP multicast group. The subscriber changes the channel by leaving one group and  linking a different group. IGMPv1 is not suitable for IPTV because it does not include an explicit Leave capability. The client will  glide by to receive all requested stream until the multicast router issues next query. The standard for IGMPv2 and IGMPv3 major difference is shown in Table 5. IGMPv2 supports  either Source Multicast (ASM) networks and which allows host to specify which multicast group it wishes to join.Most deployed IPTV clients suppor   ts IGMPv2. The Major enhancement in IGMPv3 is that it allows Support Specific Multicast (SSM). Host can specify the source address it wants to listen to. Heres basic IGMP operation involving two devices  IGMP host (client or STB)  issues  cognitive contents to join or leave a multicast group. The client also responds to queries from the multicast router.  IGMP router  responds to the join and leave messages to determine if multicast groups should be forward out an interface.  semestral queries are used to discover from error conditions and verify requests.The IGMP router receives multicast groups either through the use of a multicast protocol such as PIM or  passive flooding. It is the termination point for IGMP messages and does not send any IGMP information to its upstream neighbors. pic Fig. 16. DSL Access Network IPTV Service In xDSL IPTV architecture, the subscriber initiates channel change requests and responds to status inquiries. The Routing Gateway (RG) at the subscribers     spot and DSLAM aggregate traffic from multiple subscribers in order to act on request from the STB.However, IGMP networks were not originally designed to have networking equipment between IGMP client and the IGMP routers. This creates some challenges to the multicast implementation  Excessive multicast traffic When delivering high bandwidth IPTV over broadband network, it is important to ensure that IPTV channels are forward only to those subscriber currently viewing them since bandwidth is scarce. If the intermediate devices are unaware of IGMP flows then all multicast traffic is broadcast out all ports  Excessive IGMP traffic  senseless bandwidth is consumed as IGMP flows are broadcast to across the network.A single STB IGMP request can result in responses from thousands of IGMP peer clients.  Excessive time to Leave a group With small spare bandwidth in broadband networks, Leave request often must be processed  before additional join request can be served. To mitigate above chall   enges, several techniques are proposed and developed in intermediary devices Local Replication,  representative routing, proxy Reporting, and straightaway Leave. Local replication, IGMP snooping from DSLAM, allows DSLAM to inspect incoming IGMP Join and Leave request and take appropriate action.If the channel being requested to view is already being received at the DSLAM, it will replicate the stream and forward to the subscriber. The DSLAM builds a table to track which channel are being forwarded to each port. pic Fig. 17. DSLAM with IGMP Snooping  procurator routing works by allowing intermediate device (DSLAM) takes active role of terminating all IGMP flows. This makes DSLAM to act as IGMP host and responds to all incoming requests. DSLAM will  animate the IGMP request and use its own IP address as source.The major benefit of proxy routing is scaling since router is not aware of individual subscribers. pic Fig. 18. IGMP Proxy Routing Proxy Reporting reduces the number of IGMP pac   kets flowing across the network by selectively dropping IGMP packets that are not need to be forwarded. The Proxy Reporting can be subdivided to two categories Query  quelling and Report Suppression. Query Suppression reduces traffic between the DSLAM and the subscriber premises by having the DSLAM intercept and respond to IGMP queries sent by the router.DSLAM will never send a specific query to any clients and forward general queries only to those client receiving at least one multicast group. pic Fig. 19. Query Suppression. Report Suppression reduces traffic from DSLAM to the router by having DSLAM aggregate the response. The DSLAM can intercept IGMP reports coming from STB and  beforehand a summarized version to the IGMP router only when it is necessary. There are two categories of reports. Unsolicited membership reports are forward when first subscriber joins a multicast group or last subscriber leaves a multicast group.This tells router to begin or  collapse sending channel to    this DSLAM. Solicited membership reports are forward once per multicast group. The DSLAM will aggregate multiple responses together into a single membership report to save bandwidth. pic Fig. 20. Report Suppression  fast leave alleviate IPTV challenge to change channel  rapidly. The standard IGMP Leave operation for channel change is as follow  The STB sends a request to leave one multicast group  Router responds by issuing Membership Query to confirm the request. The STB responds with a Membership Report which does not include the multicast group By implementing immediate leave, STB can leave the multicast group by just simply sending a request to leave one multicast group 16. pic Fig. 21. Standard IGMP Leave and Immediate Leave. The emerging IPTV deployments utilize Real-time Transport Protocol (RTP) in order to deliver media content. Unlike UDP, RTP protocol can provide sequence  come to maintain packet ordering and detect losses, and timing information to determine network delay    and synchronize timing between senders and   liquidators.RTP control protocol maintains session state between senders and  receivers and report sender and receiver statistics bi-directionally 17. The rapid acquisition is illustrated in the Fig 22 flow diagram below. pic Fig. 22.  rapid Acquisition Flow Diagram 1) The RTP receiver sends a Multicast Leave message to its upstream multicast router to leave the current multicast session and end the currently viewed channel. 2) The RTP receiver sends a feedback message to the feedback target asking for rapid acquisition for the session it wants to join. In this feedback message, the RTP receiver can specify its specific requirements. ) The retransmission server receives the feedback message and decides whether or not to accept the request. If the retransmission server accepts the request, it sends a message to the RTP receiver that describes the  blow up that the retransmission server will generate and send, including the indication when    the RTP receiver should join the new multicast session. The unicast burst stream consists of retransmission of a specific block of packets which will allow the RTP receiver to begin displaying video without waiting for a certain random access point to arrive in the multicast flow.If the retransmission server denies the request, it informs the RTP receiver immediately. 4) If the retransmission server accepts the request, it transmits the unicast burst data and any additional message(s) needed to  leave the key information about the new channel. The key information is used to prime the decoder inside the IPTV STB so that it can start  decrypt sooner. The unicast burst continues at a higher than natural rate until the unicast burst catches up with the real-time multicast flow. The sustainable burst rate depends on the access network link characteristics. ) At the appropriate moment (as indicated or computed from the burst parameters), the RTP receiver joins the new multicast session b   y sending a Multicast Join message to its upstream multicast router. 6) The RTP receiver starts receiving the multicast flow and completes the rapid acquisition. The STB will not join multicast session immediately with rapid acquisition since there would not be enough available left over on the access link. By utilizing unicast burst sent from the retransmission server o catch up with the multicast flow in a reasonable amount of time before joining to multicast group allows faster channel switching capability  kind of than joining multicast group immediately 18. Cloud Computing service in IPTV IPTV videos can be delivered to subscribers through various different network structures. For many years, Proxy servers have been utilized to decrease network traffic and delays through high speed and robust connection. Telco companies are looking for ways to keep service calls rejections to minimum through cloud service for on-demand IPTV service. Figure below shows on-demand IPTV service for    cloud architecture. pic Fig. 23. On-demand IPTV cloud services Video can be streamed from any of the virtual servers by load balancing among server and handle peak loads by avoid overload to achieve continuous, high utilization levels of servers. Virtual servers can provide low cost computing resources. The Virtual server acts like a dedicated server but it co-reside on a single physical machines acting as multiple physical dedicated server. However, if too many virtual servers reside on the single physical machine, services may face  paradox due to scarce computing resource per virtual server.Virtual storage through cloud computing allow easy share of resources among themselves. Physical storage is virtualized into virtual disk, which allows storage consolidation across heterogeneous vendors and protocols, enabled by dynamically growing and shrinking of storage through live migration, in the  try storage area network to be used by applications 22. F uture application of IPTV The k   ey to differentiating IPTV from traditional TV service of VOD and Network-based personal video record (nPVR) is the real-time interactive application and social TV.With FTTx or Gigabit Ethernet providing more bandwidth in broadband network allows new killer application to  maximise the value of the IPTV service. A) SayUTV SayUTV service allows users participation into TV sports, discussion, variety show, and so on. SayUTV allow mixing their video and sources into providers content to allow maximum interactive and customize IPTV content. The subscriber can click participation  clitoris on SayUTV GUI. After service provider or host of the content allows his/her participation, the subscribers audio and video content is mixed into programs content.All the viewer of the content can view the participants image and voice. pic Fig. 26. SayUTV Service System Architecture SayUTV service divides the role of users into three major roles  Controller  who creates a service session and has a contr   ol over that session.  Participants  who joins the session and contributes his/her own multimedia content.  Simple Viewer  who enjoys this service in a passive way pic Fig. 27. SayUTV Implementation. SayUTV is an advanced IPTV service, which combined with bidirectional multimedia communication technologies allowing interactive user-participation 20.B) IPTV Interactive Online Shopping In order for IPTV service provider to maximize the profit from IPTV service require smart ad insertion based on customers preference. TV series and sports media are well known for effective product advertisement aid. Apparels worn by a main actress of TV series or MVP sports athletes have greater potential for larger sales than conventional display by online  obtain website. In order to provide customers shopping craving while  ceremony TV series or sports  emergence is to add additional information to the product description field such as TV series name, and character or athletes name.This will allow c   ustomers place some tags on that particular product through  notice particular TV series or service provider can collect customers preference based on content and insert smart ad targeting each subscriber. pic Fig. 28. Shopperama Service Screen in Korea Shopperama is OTT provider in Korea providing series, which have broadcasted through a TV station, online along with smart ad insertion. The apparels worn by main actors and products inside the episode are displayed in a synchronized manner with video content as shown in Fig 25.This allows customer to shop for products very easily while watching TV series and reduce customers burden of  toilsome to find particular product 21. To improve interactive online shopping with IPTV service still needs many enhancements to fully flourish in E-business model.  carriage targeting content to users is estimate to be 20 billion dollar industry and in order for IPTV interactive online shopping to gain market share requires smart integration of cros   s layer platforms. C) Final Remarks With IPTV service deployment, Cable Company is afraid of cord-cutting case.The IPTV service is gaining popularity amongst consumer and there are many opportunities for new killer application to integrate with IPTV service. In this paper, we described current IPTV architecture in the market and presented recent efforts to improve IPTV technology. Emerging IPTV mobile systems are also gaining a lot of attention and consumer trends demonstrate that IPTV will continue to be in demand. Acknowledgment I would like to thank Prof. G K Chang for giving me an opportunity to work on this topic and learn more about multicast protocol to provide IPTV service.I was able to learn more about IPTV architecture and current trend in network research in video streaming protocol. References 1 IPTV and the Future of Video Services online  operational http//www. employees. org/acbegen/files/IPTV_Tutorial_CCNC_2010_abegen. pdf 2 U. S. Multichannel Subscriber Update and G   eographic Analysis, white paper, SNL Kagan, Dec. 2012. 3 Ali C. Begen, Error control for IPTV over xDSL networks, in Proc. IEEE Consumer  communication theory and Networking Conf. (CCNC), Special Session on IPTV Technologies and Applications, Las Vegas, NV, Jan. 008 4 A. Yarali and A. Cherry, Internet Protocol Television (IPTV).  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