Interactive Video Delivery Services

Interactive Video talking to ServicesVideo-On-DemandInteractive ServicesInteractive video delivery go argon a fundamental change in the TV embrasureparadigm. They shift the delivery paradigm from carrying many simultaneous par all(prenominal)elstreams (channels) to bingle that carries concurrent accesses through separate channels into adatabase. Traditionally, in a air out TV system of rules, many stations broadcast their programssimultaneously and the exploiter selects a specific channel to view. As a result, a drug callr isrestricted to a chronology of parallel and competing programing whereas, an interactivesystem makes all computer programming available to its users without this restriction. thither is notemporal restriction. All programming becomes available any time to the user.Types of Interactive ServicesBased on the heart of interactivity allowed (adapted from 4), interactive services wad be classified into round(prenominal) categories.The user is a passiv e participant and has no control everywhere the session in broadcast (No-VOD) services that are similar to broadcast TV.The user signs up and pays for specific programming, similar to existing CATV PPV services in pay-per-view (PPV) services.The users are grouped based on a threshold of engage in quasi video-on-demand (Q-VOD) services. By electrical switch to a contrasting group, users can perform rudimentary temporal control activities.The functions like forward and avoid are simulated by transitions in discrete time intervals (on the recite of 5 minutes) in near video-on-demand (N-VOD) services. The multiple channels with the same programming skewed in time 5, 15 can provide this capability.The user has spot control over the session evidenceation in true video-on-demand (T-VOD) services. The user has full-function VCR (virtual VCR) capabilities including forward and reverse play, freeze, and random positioning. For T-VOD, only a wiz channel is necessary multiple channels become redundant.Technological InhibitorsThere are other inhibiting issues to the ubiquitous deployment of interactive multimedia lotions than just technical issues. In the digital environment, information is readily copied, reproduced, and altered, jeopardizing the established markets of the information providers. To coax an information provider to accept an all-digital system, certain incentives like mechanisms like encryption to protect intellectual property rights that go forth maintain their data and thusly help them stay in business are needed. (The Internet does non copy data, people copy data.)System Components for Video-on-Demand5A detailed analysis of these issues is beyond the scope of this paper. An interesting survey of theintellectual property rights problem has been provided by Samuelson 14.Hundreds (if non thousands) of users with different viewing preferences will access a VOD system simultaneously. The quality of each session must remain within stipulate bou nds to achieve node satisfaction. This jibes the quality of the system. We will survey the private technologies in the context of an end-to-end architecture for a VOD system.A regular(prenominal) VOD scenario contains a local database and server connected to user homesvia a discourses nedeucerk. The user home consists of a ne devilrk larboard coupled to adisplay 4. The user interacts with the system via a mouse or a computer keyboard.Fig. 2 illustrates this architecture.user interfaceand displayhigh-speed gritlocal databaselocalserverhomeviewernetwork interfacemultimedia archive and distributormultimedia archive phase 2 A Simple VOD ArchitectureManagement of System Resources in VODWe determine some of the technical problems in designing a VOD system in the previous sections. A VOD system is required to support a tremendous customer population and many depiction titles. Most existing prototypes are constricted to laboratory or office environments and support at just about a few hundred users and up to a hundred motion-picture shows. coarse scale commercial systemsshould need to more closely match the per-user mental imagery requirements and usage patterns toachieve economic feasibility. In this section, we look over some of these problems and discussexisting research in this area.Resource Reservation matchless of the fundamental problems in developing a VOD system is one of terminal and network I/Obandwidth carement. The VOD system possesses a finite amount of resources measured interms of storage I/O and communication bandwidths. As various customers compete for the samesystem resources, efficient schemes that pick up fairness of allocation have to be designed.The service provider wants to reelect the maximum revenue from the offered services. Abalance between these two oft opposing requirements is necessary to tap the potentialbenefits of the system. The first step to forge this problem is the development of anaccurate system model. We use the model proposed in Fig 2 as the basis for the remainderof this discussion.The end-to-end VOD system comprises of three basic components the storage server,the network, and the user interface. The metadata server provides an additional take ofcomplexity to the system model. The time dependency of continuous media requires theVOD system to ensure that the data transmission mechanism can provide for strict deadlines.If these deadlines are missed, it is possible for the quality of the session to degrade. To ensure customer satisfaction, resources should be mute along the entire data path of a connection on a per-session basis. The complexity of the resource reservation mechanism depends on theapplication under consideration. Interactive services need the resource reservation to be made per-session along the entire data path, including at the source.A important factor which is affecting resource reservation is Quality-of-Service (QOS). The common interpretation of QOS is from a ne twork perspective rather than a user or customer perspective. A more suitable view makes use of the two perspectives and yields twoQOS characterizations (we can call them delivery quality and system QOS). A presentchallenge is to identify the mapping from delivery quality to system QOS for a range ofsystem design parameters (e.g., data compression and network switching modes).User Traffic CharacterizationAlthough customers access the VOD system randomly, having a priori acquaintance aboutuser access patterns can lead to a more efficient design. The system can make use of this information to manage network and storage bandwidths. As an example, if the traffic characteristics indicate that a characterisation is popular at a particular site, the system can repeat the movie locally to increase availability.The access pattern of users to the system will not be uniform over a given24 hour period. Typically, one would expect the lode to be low to view as during thedaytime and to increa se gradually through the evening and decrease again during the night.A hypothetical graph characterizing the access to a VOD database for a 24 hour periodis shown in Fig. 4. The access to the database is high during the evening hours, peaks ataround 900 PM, and is low-to-moderate during the day. This access pattern can be employ fordesigning schemes for various considerations like resource management to update popularity tables, distribute data, and reconfigure the system during off-peak hours.05 10 15 20time-of-daydatabase-loadFigure 4 A Schematic Daily-Access Model for a VOD System analogous models can be implemented and maintained for different geographical regions, moviecategories, and individual titles. Such models are able to accommodate the differences in programming choices (e.g., childrens movies are more popular during the early evening hours) of different user groups. However, the complexity of these models, and their tractability is still to be established.Load rappro chementAn issue related directly to resource reservation is load balancing. The load balancing of VOD can be viewed as a combination of two sub-problems (i) The movie-storageallocation problem and (ii) the resource location and connection establishment mechanism. tear down though these problems are solved more easily individually, they are not independentwith respect to performance. From the perspective of a generic interactivesystem, result these issues is an open problem however, simplifications can yield tractable solutions.As an example, if one assumes that a VOD system supports only stored data i.e., movieshave to be digitized and stored in the lead they can become available online, then the datacharacteristics of a movie are well known in advance (e.g., the system has a priori knowledgeabout the average bandwidth, burst rates, burst durations, etc.). This knowledge in one case available, can be used to simplify the design process. Making use of the metadata mechanism as desc ribed in Section 3 simplifies the tax of management by decoupling the storage problem from the location problem.