Video On Demand Essay, Research PaperVideo on DemandVideo on Demand ( VOD ) has been actively pursued for the past several old ages. VOD would carry through three distinguishable intents in footings of community service. These include synergistic distance acquisition, picture conferencing, and amusement. While it is the first two, picture conferencing and synergistic distance acquisition, which would function to the best advantage in footings of instruction and concern ; it is the last, amusement which has the most appeal to the largest figure of people.
The application of picture on demand in footings of instruction and concern is presently being utilized in distant acquisition plans and company preparation plans around the state.Video on demand can take many signifiers. In the simplest of signifiers it is a series of Video Cassette Recorders ( VCR ) located in a control station which are networked to either places, schoolrooms, motel suites, etc. The client merely calls in their order and a technician retrieves the tape and dramas it over the centrally located VCR. This apparatus and somewhat more complex 1s which operate under similar processs, with clients telling merely single plans, are referred to as one-way multicast ( Shenoda ) . Video on demand is peculiarly adapted to & # 8220 ; narrowcasting & # 8221 ; the ability of the webs to economically present specialized telecasting programming even for little audiences ( O & # 8217 ; Brien ) .Conveyance StandardsVideo on Demand is supported by two major systems and transport criterions: Telecommunication Union-Telephony ( ITU-T ) Recommendation H.
320 Audiovisual Systems specifications and related criterions and Motion Picture Experts Group ( MPEG ) systems and criterions ( Shenoda ) . Both ITU-T and MPEG were developed with the intent of back uping compaction and encryption of picture and audio signals ( Shenoda ) . They were besides developed to those signals with data/graphics and control signals every bit good as others and to transport those through the webs which are already in being today ( Shenoda ) .It is the H.
320 specification which is most applicable for narrowband time-division multiplexed ( TDM ) webs ( Shenoda ) . MPEG on the other manus is more suitable to broadband packet-oriented webs and it is these webs which maintain end-to-end quality of service ( Shenoda ) . A 3rd type of specification is motion JPEG but this specification, while it is utile in high-quality picture such as that utilised in studio plan presentation, is of less general involvement due to the high sum of bandwidth it consumes ( Shenoda ) .An implicit in physical bed and an overlying H.221 bordering criterion is recommended for ITU-T H.320 ( Shenoda ) .
Shenoda besides reveals that:& # 8220 ; Above bordering reside H.230 control signals, the G.7xx suite of digitized-audio protocols, and the H.261 codec criterion for digitized picture.
Data or other information can be multiplexed with picture and sound utilizing the H.221 bordering criterion.H.320 specifies the system mention constellation and basic demands.
It is based on encoding the plan elements to suit in a P x 64-kbit/second channel, which can be from 64 kbits/s to 1920 kbits/s. One or more channels are framed to suit standard transmittal rates ( T1 or E1 ) utilizing the H.221 framing recommendation. ( Shenoda ) & # 8221 ; .It is the type of system described above by Shenoda which most frequently finds its use in current distance-learning and videoconferencing applications such as that which will be described below. These systems are able to relay sensible quality picture utilizing higher-capacity channels of 1 Mbit/s or more while at the same clip holding the ability to use bing webs ( Shenoda ) .
ITU-T recommends H.261 for videocompression in H.320 systems ( Shenoda ) . This recommendation is based on changeless picture frame frequence trying and block encoding where there are 625 to 525 lines of picture and where & # 8220 ; a block is a figure of lines with a figure of pels per line & # 8221 ; ( Shenoda ) . Encoding allows the discrepancy of the sum of information transmitted wit the concluding consequence being a variable quality of picture as good at the receiving or decrypting terminal ( Shenoda ) .
The purpose of this apparatus is to let the use of different but changeless transmittal rates ( Shenoda ) . This allows the user to take the transmittal rate which is most economical in footings of maximising video quality and of minimising conveyance cost ( Shenoda ) . Guidelines as to what is typical in this type of apparatus is that quality foremost becomes acceptable get downing with 384 kbits/s and improves well at 1 Mbit/s and above ( Shenoda ) . There are legion other recommendations for multiplexing, voice compaction, the use of double cameras in teleconferencing applications, etc. ( Shenoda ) .MPEG differs form the above criterions in that the protocol stack incorporates a & # 8220 ; core physical bed, a web and conveyance version sheathing and several elements above web conveyance ( Shenoda ) . & # 8221 ; Other considerations include plan cyclosis ( multimedia multiplexing ) which incorporated digitized sound using ISO/IEC 13818-3 voice cryptography ( Shenoda ) .
Multimedia multiplexing besides incorporates digitized picture using H.262 picture codec and signals for user to user control ( Shenoda ) .MPEG is broken into MPEG-1 and MPEG-2 with the latter holding the highest declaration and a richer sentence structure ( Shenoda ) . MPEG-1, nevertheless, allows even lower transmittal rates because of its ability to encode at even lower declaration ( Shenoda ) . This is peculiarly utile for applications such as CD-ROMs ( Shenoda ) . Numerous ITU and International Standards Organization are associated with MPEG ( Shenoda ) .
On-line ApplicationMany of the criterions which address clocking, synchronism, hold, packetization, version beds and connexion direction and routing are presently in topographic point and are in a changeless province of development, others are being established ( Shenoda ) . One interesting characteristic of these systems is their online application. This use offers non merely long-distance acquisition but besides the integrating of informations services and voice trunking. Software has been developed specifically for the intent of networking schoolrooms to ease them to at the same time draw files from the Internet and to heighten the acquisition experience ( Shenoda ) .On-line applications can be supported over bing ATM webs. Shenoda observes: & # 8220 ; H.320 webs can be supported on ATM webs today, much like voice, using CES between terminuss and MCUs. For illustration, ADC Kentrox AAC-3 equipment is used to back up a distance-learning application among 40 schools, though non all schools are on-line yet.
It offers synergistic picture learning plus integrating of informations services and voice trunking on the same ATM web. Particular package has been developed in the web control system to take attention of the programming. At preprogrammed hours, the web control system reconfigures the ATM VCCs to complect the appropriate schoolrooms with each other, and set up the MCU to execute the proper redistribution of audiovisual signals. In the interim, any category can at the same time draw files from waiters across the Internet via the gateway router. In this mode, information may be pulled from any Web waiter to the multiple schoolrooms take parting in the session ( Shenoda ) ” . While preparation and certification for online systems is critical for its efficient usage, database considerations are non significantly different from typical demands nor are entree and security demands.
Business ApplicationsAs concerns move from & # 8220 ; Main Street & # 8221 ; to a planetary presence, they experience more and more demands in footings of engineering. Often times the assorted fractions of a concern are spread across broad geographic countries and coordination between the assorted offices is easy disjointed. Technological promotions such as the telephone, e-mail, facsimile, and videoconferencing go the line of lifes which connect one unit with the others. Videoconferencing is peculiarly utile in that it allows the transmittal of ocular hints which replicate those of traditional & # 8220 ; face-to-face & # 8221 ; interactions ( Lantz ) .Videoconferencing is an plus to communicating and provides a service that no other engineering can presently fit in footings of the clear transmittal of information. This includes both ocular images of others involved in the conference and of informations such as charts and spreadsheets which are being presented.
Educational Applications of Video on DemandEducators have obtained the capableness about overnight to transform dry text edition larning into disputing and exciting synergistic picture coupled with prerecorded picture. Many first-class illustrations of this type of use of picture on demand are available today in concerns and schools across the state. One such illustration is an anti-violence plan for schools designed to take advantage of the progresss in telecasting engineering and of picture on demand in peculiar. This plan includes a specially designed course of study referred to as & # 8220 ; Take Two & # 8221 ; . The & # 8220 ; Take Two & # 8221 ; course of study distinguishes itself in many ways but one of the most astonishing and effectual of which is the proviso of three practical field trips ( Lovett ) . Each of the three picture field trips are synergistic and to the full use the capablenesss of picture on demand and its yoke with the more traditional media of prerecorded picture tapes.
The pupils who participate in the plan are transported to assorted locations through the thaumaturgy of synergistic picture and are exposed to struggles which allow them to interact with experts in struggle declaration state of affairss ( Lovett ) . Each of the pictures were aired over the local public broadcast medium channel and take parting schools were provided with more traditional support stuffs such as texts and worksheets to supplement the miracle of synergistic picture. The pre-recorded parts of the picture practical trip were interesting and captivating every bit good but it was the unrecorded on-air public presentations made possible by picture on demand which served to do the experience most memorable and effectual.Because the & # 8220 ; field trips & # 8221 ; incorporated into the plan were synergistic the comparative disbursal of the overall plan was kept to a lower limit. This allowed the development of course of study which provided a assortment of different experiences via picture. The first & # 8220 ; trip & # 8221 ; took the pupils to the juvenile detainment installation in Jacksonville where the pupils met with detainment centre staff where they viewed a picture picturing life behind bars for immature wrongdoers ( Lovett ) . Students were farther made a portion of the experience by being able to name or facsimile inquiries to the installation staff ( Lovett ) .
The preparative stuff for this field trip exposed pupils to the construct that many when faced with struggle choose flight over combat. Synergistic picture facilitated the debut of a reformed blowout who was available to reply pupil inquiries ( Lovett ) .The 2nd field trip introduced the pupils to the Duval County Sheriff who discussed the assorted ways that police officers incorporate conflict declaration into their responsibilities ( Lovett ) . Again, this & # 8220 ; trip & # 8221 ; utilised synergistic picture in add-on to more conventional instruction methodological analysiss.
Students saw many of the same constructs sing struggle declaration that were depicted in their course of study and were once more able to facsimile and name in inquiries. The 3rd field trip concentrated on the possible effects of unsuccessful struggle declaration and focused on the physical effects of such failure ( Lovett ) . These effects were reinforced by synergistic picture having a physician stand foring the injury centre at Jacksonville & # 8217 ; s University Hospital and a staff member from a shelter for abused partners and kids ( Lovett ) . As with the old two videos pupils were allowed personal engagement through calls and facsimiles ( Lovett ) .DecisionsAlthough the construct of picture on demand has been tossed around for some clip and utilized on a small-scale footing it is non yet a feasible commercial option on a large-scale footing ( Shenoda ) . It will doubtless be Video on Demand & # 8217 ; s use in concern and application which will convey it to the head in footings of commercial applications directed toward amusement.Beginnings CitedLantz, Keith A. New Media: Sounds and images bridge the spread: Businesss progressively are utilizing picture to complect distant company locations.
Serving them could be an excelle, Telephony, 8 Dec 1997.Lovett, Marcelle C. ; Walzak, David P.
North Florida Distance Learning Consortium & # 8217 ; s advanced distance. , T H E Journal ( Technological Horizons In Education ) , 1 Aug 1997.O & # 8217 ; Brien, Tom.
Cable Smarts Up: & # 8216 ; Narrowcasting & # 8217 ; Proves a Success, The World & A ; I, 1 Feb 1997.Shenoda, George. Chief Technical Officer, ADC Kentrox, Portland, Ore. , ATM is ready to travel MPEG sound, picture, Electronic Engineering Times, 20 Jan 1997.