Video on Demand (VOD)
On Demand (VOD in short) is a programming system that allows subscribers to rent movies or to watch videos at home instead of the traditional method to rent the movie CDs at the DVD shop. Viewers can either watch the programs in real time or download and view them later. The subscriber can also use the remote control to pause, rewind or fast-forward these videos with their remote control. In Singapore, this service is usually provided by Telco Company which the function is available in the TV set-top box. Alternatively, viewers can use watch VODs programs using their laptops or smart devices if they subscribe to popular channels like Netflix online or downloads VOD apps on their mobile phone.
In the beginning, Video On Demand takes a long time to download the video due to the lack of available network bandwidth. Although VOD can function well over a vast geographic region or using the satellite-based network as long as the subscriber’s demand for the program is modest. But if there are a huge number of consumers demanding multiple programs continuously within the particular time period, the huge amount of data that is involved in terms of megabytes or even gigabytes can easily overwhelm network resources and even cause the servers to crash.
Technology experts have mitigated this issue by storing the programs via multiple servers that are distributed geographically to provide programs to local viewers on demand. This method greatly increases the availability of the programming 24/7, overall stability and reliability of the system as compared with the use of a single gigantic repository. The VOD system also allows the local providers to maintain their systems and set up billing structures using software that is independent of each other. A good example of such applications is known as Asynchronous transfer mode (ATM) switching technology. Which works especially well in this application.
The concept of Video On Demand is actually not new as the service is first launched in Hong Kong during the early 1990s which are followed by the USA at the beginning of the year 2000. Now VOD is a popular service that is provided by telco, cable or internet service providers across the world. Besides programs for entertainment purpose in the subscriber’s home, VOD is also common in luxury hotels or educational institutions for academic purpose and also used to enhance presentations in videoconference environments.