SDV Presentation
- 1. Introduction to SDV Owen Lin April 18, 2007 Some information obtained from: Scientific Atlanta – SDV Overview BigBand Whitepapers –The Statistics of SWB
- 2. What Is SDV and What Does It Do? Switched Digital Video A technology which brings multicast efficiency to digital video distribution Enables MSO's (Multi Service Operators) to offer a wider variety of programming Efficiently manages their HFC (Hybrid Fiber/Coax) network's bandwidth. Allocates bandwidth to requested channels Frees up bandwidth from services no longer in use Traditionally, a broadcasted channel has permanent bandwidth allocated to it Wasteful if nobody is watching the service. Detailed logs of bandwidth allocation and channel viewership
- 3. Why All the Rage? Competitive advantage, bringing the best for the least Reduces investment cost - scales logarithmically to programming services, rather than linearly SD (Standard Definition) channel uses about 3-6Mbps HD (High Definition) channel requires approximately 15-22Mbps, depending on the amount of motion and frequency of scene changes. A 256-QAM can supply 38.8Mbps. That translates roughly to 9 SD channels or 1, maybe 2, HD channels.
- 4. Example of Numbers An MSO broadcasts a 300 channel lineup, 20 of them HD's 280 sd * 4 Mbps % 38.8 Mbps = 29 Qams needed per node * 20 hd * 18 Mbps % 38.8 Mbps = 10 QAMs needed per node * 39 QAMs are required per node (200-2000 tuners, varies by MSO) % = modulus An MSO uses SDV to offer a 300 channel lineup, 20 of them HD’s The 80/20 rule followed by tv watchers 56 sd, 4 hd channels are being watched by 80% of the audience 8 QAMs required Covering vast majority of audience, approx 100 unique streams about 1/3 the channel bandwidth MSO investment in QAMs at the hub level are heavily reduced
- 5. Additional Research BigBand, top 5 MSO, and S-A STB test trial on SDV 915 subscribers 171 switched channels 100 streams resourced (only 67 were required in hindsight)
- 6. Kagan Research A study conducted by Kagan Research found that at any given moment the actual number of broadcast channels being viewed within a given node was far less than the number being broadcast .
- 7. Why Switched Digital Video? Bandwidth SDV Gives your site more flexibility to deliver more of the services that consumers want today Allows greater bandwidth capacity because NOT every channel is delivered at the time Unused Capacity Switched Digital Video Switched Channels Everyone could get their own special channels: increased appeal of overall package to ALL subscribers Broadcast Channels Audience Broadcast Channels Current Analog & Digital Broadcast Approach Only the most popular channels are offered due to capacity constraints “ The Long Tail”
- 8. Why Switched Digital Video? Summary Traditional Broadcast Switched Digital Video 200 Programs Offered 20 QAMs HFC Bandwidth Required 300 Programs Offered 30 QAMs HFC Bandwidth Required 200 Programs Offered 6-8 QAMs HFC Bandwidth Required 300+ Programs Offered n QAMs HFC Bandwidth Required Bandwidth scales as number of offered channels Immediate bandwidth savings HFC bandwidth scales based on viewership HFC bandwidth required is independent of number of offered channels MSOs can save bandwidth by delivering programs based on viewership
- 9. Section: SDV Elements DNCS SDV Manager SDV Server Mini Carousel DCM NetCrypt Switches & Routers QAMs STB Client
- 10. SDV Elements Management Network – Key Players Management HFC Network Video Content IP Network Control IP Network QPSK Content Sources DNCS DCM SDV Server GQAM SDV Client (on STB) Management & Provisioning Server Interactive Session Request Mini Carousel Channel Change Message Session Binding Shell Session Setup IGMP Join Out-of-Band Channel Video Sources Groomed Video Encrypted Multicast Video In-Band Channel NetCrypt
- 11. SDV Elements DNCS DNCS System Release (min 4.2.0.2xx) Features enabled with separate licenses Session Resource Manager (SRM) Governs access to content and network resources Allows sharing of those resources by various applications SDV Manager The user interface for control of the SDV servers and system Provides a means for operator configuration of the service group assignments and various settings for the SD V servers. NetCrypt ™ Bulk Encryptor enabled SDV enabled DNCS
- 12. SDV Elements SDV Server The SDV server is part session manager in that it communicates directly with settops requesting channel changes It is also part resource manager — it requests that shell sessions be set up on a QAM feeding the required service group Reallocates unused bandwidth Generates the Mini Carousel The SDV also monitors Bandwidth Channel Changes SDV Server
- 13. SDV Elements Mini Carousel Mini Carousel Carries information about the programs that are currently being carried in the SDV service Includes IP addresses of primary and back up servers Operates between the SDV Server and the SDV Client Provides a method of distributing tuning information to enhance channel change operation
- 14. SDV Elements Content Delivery Network – Key Players Content Delivery HFC Network Video Content IP Network Control IP Network QPSK Content Sources DNCS DCM SDV Server GQAM SDV Client (on STB) Management & Provisioning Server Interactive Session Request Mini Carousel Channel Change Message Session Binding Shell Session Setup IGMP Join Out-of-Band Channel Video Sources Groomed Video Encrypted Multicast Video In-Band Channel NetCrypt
- 15. SDV Elements DCM / Staging Processor The Scientific-Atlanta staging processor is the Digital Content Manager (DCM) Grooms and conditions signal sources Aggregates multiple MPEG sources Converts MPTS to SPTS Encapsulates MPEG into IP/GbE Outputs unicast IP or multicast IP as needed Clamps content streams to specified bandwidth DCM / Staging Processor
- 16. SDV Elements NetCrypt ™ Bulk Encryptor The Bulk Encryptor receives the IP content streams from the DCM / Staging Processor SDV streams are treated as broadcast streams for purposes of encryption Generates and sources the IP multicasts for encrypted switched streams Also used to generate multicasts for unencrypted streams. Bulk Encryptor
- 17. SDV Elements Switches & Routers All connections are passed through router(s) which support IGMP v3 Switches & Routers
- 18. SDV Elements QAM Modulators (GQAMs / Edge QAMs) QAMs receive MPEG information encapsulated as UDP streams* from the NetCrypt ™ Bulk Encryptor QAMs request and terminate IP multicasts , and modulate the content as MPEG transport packets onto an RF carrier GQAM
- 19. SDV Elements STB Client The STB requires a SARA (S-A resident applications) OS version that supports SDV Provides customer interface for switched services Stores last known Mini-Carousel data Registers all user activity with SDV Server Settop with SDV Client
- 20. Section: Setup and Signal Flow SDV Components Provisioning and Channel Change Major SDV Channel-Change Scenarios
- 21. Setup Flow - SDV Components HFC Network Video Content IP Network Control IP Network QPSK End-to-End System Solution and Integration 6.) GQAM: Session-based modulator with IP/GbE input, Issues IGMP message to “join” multicast group for SDV, and may also handle unicast VOD streams 1.) DCM / Staging Processor: Aggregates multiple MPEG sources, Clamps VBR programs to CBR, Converts MPTS to SPTS, Encapsulates MPEG into IP over GbE output, Addresses unicast IP for encrypted programs and multicast IP for unencrypted, and Performs DPI for ad insertion 2.) DNCS with SDV licenses 4.) NetCrypt Bulk Encryptor: IP network-attached encryption, Up to 4 Gbps, and Addresses multicast IP for distribution DNCS SDV Server GQAM SDV Client (on STB) Content Sources DCM 8.) SDV Client: Provides customer interface for switched services, Stores last known Mini-Carousel data, and Registers all user activity with SDV Server 5.) SDV Server: Intel Server running Linux OS, Requests bandwidth and shell sessions from the SRM Manager, Binds shell sessions to multicast content, Distributes Mini-Carousel for topology, client configuration, and updated tuning information and Processes channel change requests 5) SDV Mgr: User interface in DNCS for control and configuration of the SDV Servers and service group settings SRM: Allocates QAM resources for different applications including VOD and SDV, and Reclaims bandwidth from Servers as needed 7.) Switch/Routers: Standards-based with IGMPv3 SSM, Switches streams to appropriate GQAMs, and Maintains IGMP membership tables NetCrypt
- 22. Signal Flow Major SDV Channel-Change Scenarios SDBProgramSelectConfirm SDBProgramSelectRequest DNCS “ SRM” Settop QAM SDV Server ServerInteractiveSessionRequests ServerInteractiveSessionConfirms QAM Shell Session Setups SDBProgramSelect Request/Confirm Case 1. Program already to Service Group and in Mini-carousel Case 2. Program already to QAM chassis for another Service Group Case 3. Bandwidth available on QAM that is not member of that multicast group Router SDBProgramSelectConfirm SDBProgramSelectRequest Bind to multicast w/ bit-rate IGMPv3 “Join” Case 4. No bandwidth available on current QAMs. SDV server must request additional bandwidth from SRM SDBProgramSelectRequest IGMPv3 “Join” SDBProgramSelectConfirm Bind to multicast w/ bit-rate Bind to multicast w/ bit-rate