Why Do We Need Fiber?

12 452 0
Why Do We Need Fiber?

Đang tải... (xem toàn văn)

Tài liệu hạn chế xem trước, để xem đầy đủ mời bạn chọn Tải xuống

Thông tin tài liệu

WHITE PAPER Why Do We Need Fiber? (The need for more speed) A Study on Video Over IP and the Effects on PON Architectures Why Do We Need Fiber? (The need for more speed) A Study on Video Over IP and the Effects on PON Architectures It can be argued that eventually, everything will be IP; Voice, Data, Video and even wireless, completing the “IP Quadruple Play.” When and how soon is anyone’s guess, but the impact on existing and future networks is going to push the need for more speed (bandwidth) IP to and in the home will usher in a new range of entertainment and services: − Voice over IP (VoIP) − IPTV (SDV – Switched Digital Video) − Music Distribution − Personal Video Recorder (PVR) − Video On Demand (VoD) − High Definition TV (HDTV) − Interactive Television − IP Enabled Appliances (Smart Appliances) − Security, Environment (Smart Home) Of these services, video is the most demanding in terms of bandwidth and more significantly, how we view the quality of the entertainment (QoE) CED magazine has written several articles highlighting video bandwidth needs such as; “The Big Squeeze,” by Craig Kuhl, Contributing Editor, April 1, 2006 and “Bracing for the Impact,” by Jeff Baumgartner, Editor in Chief, CED magazine and xOD Capsule, July 2006 A Study on Video Over IP and the Effects on PON Architectures IPTV So, what is IPTV? For many, the acronym conjures up visions of hundreds of “on-demand” entertainment channels delivered anytime, anywhere IPTV (Internet Protocol Television) describes a system where a digital television service is delivered using the Internet Protocol over a network infrastructure, which may include delivery by a single broadband connection For residential users, this type of service is often provided in conjunction with Video on Demand (VoD) and may be part of combined Internet Services such as Web access and Voice over IP (VoIP), where it may then be called Triple Play Anything over IP is typically supplied by a broadband operator using a single infrastructure It promises total control by the user to customize their multimedia experience for true interactive uni-casting entertainment and services For many operators, IPTV holds the allure of tapping into new revenue sources with the delivery of advanced multimedia services over broadband networks IPTV is being enabled with the transition of moving from an analog format to an all-digital format Advances in video compression techniques are making it easier to deliver both standard and high definition audio and video The growth in bandwidth, coupled with digital video and better compression techniques, broadband can be delivered to an ever-increasing subscriber base over anything Digital Subscriber Line (xDSL) or passive optical networks (PON) networks With increased consumer demand fueling the fire, competition is on the rise As competition grows fiercer, what’s the best way to deploy IPTV? The answer, there is no single answer Today, the basic delivery mechanisms include Digital Subscriber Line (DSL), Passive Optical Networks (PON) as in fiber-to-the-home (FTTH), traditional CATV over Hybrid Fiber Coax (HFC), or some combination Each has its advantages and challenges This study investigates the key elements of IPTV over PON deployments by addressing the following four aspects: Technology: What are the enabling technologies and their availability timeline? Capacity: What are the differences between various PON implementations? Can they meet the service requirement? Cost: What are the cost differences among various PON options? Business: How are the services priced? What is the impact on revenues? Is cost a significant portion of the revenues? Technology Starting with a brief bit of history about IPTV and some of the standards that dictate how we deliver video combined with audio over an all IP format Digital Page  Broadcast Satellite (DBS) (i.e satellite TV) is not discussed in great detail Direct Broadcast Satellite (DBS) is a term used to refer to satellite television broadcasts intended for home reception, also referred to as direct-to-home signals It covers both analog and digital television, radio reception, and is often extended to other services provided by digital television systems including limited video-ondemand and interactive features A "DBS service" usually refers to either a commercial service, or a group of free channels available from one orbital position satellite targeting one country DirecTV and EchoStar are a couple of examples Typical xDSL Development and the Moving Picture Experts Group (MPEG) With current video compression technologies, neither Symmetric High Bit-Rate Digital Subscriber Loop (SHDSL) nor Asymmetrical DSL (ADSL) can provide the bandwidth required for IPTV ADSL2+ at 26 Mbps and Very highspeed DSL (VDSL) at 50 Mbps offer more bandwidth, but the tradeoff is in the distance Subscribers need to be close to the Central Office (CO) or remote terminal as the speed over any xDSL network decreases over longer distances Many operators find IPTV deployment over xDSL more attractive given existing investments in the copper plant and the need to deliver services quickly However, one of the key problems in xDSL is the delivery of standard definition and high-definition TV over MPEG2 With MPEG2, HDTV currently requires approximately 20 Mbps per channel compared to 2.5 – 3.5 Mbps for standard-definition TV (See the Table below for broadcast bandwidths of MPEG2.)

Ngày đăng: 18/10/2013, 19:15

Từ khóa liên quan

Tài liệu cùng người dùng

Tài liệu liên quan