Module 8.3 (Mobile Television FAQs)
Tina Mani gives answers to commonly asked questions on the differences between mobile television and video, video downloading and video streaming, suitable video compression standard for mobile television, content delivery network, specific regulations needed to increase the adoption of mobile television in India, etc.
- What is the difference between a mobile television and video on demand?
Mobile TV is the availability of regular TV channels to view on your mobile. Video on Demand (VoD) services make a central collection of pre-recorded content like videos available to view any time the user wants to on the mobile , PC or television.
- Do the handsets need any special features to view streaming video?
No, most of the handsets that support a high speed data connection also have video capabilities and a built in media player. These support the standard streaming protocols. However, for better user experience, an application client can be used on the handset to render the programming guide and to change channels easily.
- What is the difference between video downloading and video streaming?
Video downloading downloads the file to the mobile and then it can be played from the local storage any number of times without a subsequent internet connection to the server. In the case of streaming, the file is located on a separate streaming server and played out to the mobile over an internet connection. Chunks of the media are stored in the buffer, can start to be viewed before the entire file is downloaded.
- Where is the video content that is to be streamed stored?
The Video Content to be streamed to a mobile is usually stored in a separate storage associated with a Content Management System (CMS).
- What are the protocols used for streaming video?
The protocols commonly used for streaming video are RTSP (Real Time Streaming protocol), Microsoft Silverlight and HTTP Adaptive Streaming (Iphone).
- What determines the size of the digital content file?
The size of the digital content file is determined by the resolution, screen size or number of pixels (eg High Definition means 1920x1080), Standard Definition means 720x480), the frame rate (eg. 5 frames/sec) and the type of encoding (for eg., MP4 container with H264 is the most suitable for streaming).
- What determines the frame rate of a video?
A video is a series of fast moving pictures. To capture more action, more frames are required to be taken per second. Sports or Action videos typically require higher frame rates than news channels. The frame rate is determined at the time of creation of the video.
- What is the most suitable video compression standard (encoder) for mobile television?
H264/AVC, also known as MPEG-4 is the most suitable encoder for mobile TV, because it has the best quality for a given bitrate, and also can be used in a very wide range of applications and bit rates from very low bandwidth for a small screen like a mobile to HDTV on a big television screen. It is also an industry standard and most widely supported by the mobiles in the market.
- What is the relationship between the speed of your data connection and the bit rate at which the stream is encoded?
Usually, the stream should be played out at a rate closest to the speed of the data connection, so that the video is smooth and uninterrupted. If the data connection is too slow, the video has to buffer for some time, and only when there is enough data, it plays on the handset.
- Since the rights for the content to be played over mobiles are different from the standard rights, who in the ecosystem usually acquires these rights?
Several models are prevalent worldwide, but the most common one is where content aggregators who already work with media companies to acquire the rights for other content like music or pictures also acquire rights for the video content. They then get into revenue sharing arrangements with telecom operators to use their network to broadcast the content. Some fixed network operators who have broadcasting rights for IP Television (IPTV) or satellite TV (eg Airtel, Reliance) can work with the same media companies to extend the rights. There have been successful models outside India (eg Belgacom) where mobile operators have acquired content themselves and provided to the consumers over their network.
- What are examples of some mobile television services in India?
Mobile TV services were launched by most of the Indian operators (eg. Airtel, VF, Idea Cellular, etc) with GPRS (2G) data connections, however, the user experience at the lower data speeds was not very good. There weren’t many technology players in the market at this time either. With the 3G launches, the experience is much better now. However, the success of any service like mobile TV depends on the content as well. So far this service has not seen huge adoption. Some of the content providers like NDTV have also launched services independent of the operator.
- Are any specific regulations needed to increase the adoption of mobile television in India?
Mobile TV has two possible modes – broadcast and unicast. For the unicast mode, all it requires is a data connection that is provided through a regular 2G, 3G or 4G connection. Hence there is no special spectrum requirement for this mode. For the broadcast mode, depending on the technology (DVB-H or MBMS), special spectrum may be needed (for DVB-H). At this point, there is some contention about the use of the 698-862 MHz spectrum for DVB-H (Doordarshan), or for the use of this spectrum for BWA deployments in India . The latter approach would make sense because the general BWA spectrum can then be used for all services including mobile TV. Also the MBMS technology, which seems to be the most universally accepted broadcast technology for LTE does not require separate spectrum, but can run mobile TV in a broadcast mode using the same spectrum. Mobile TV licenses should be available to mobile operators as well.
Tina Mani works with Wavesncloud Consultants