Despite the rise in popularity of user-generated videos and other "do-it-yourself" forms of content, when it comes to authentic revenue generation, broadcast television programming is still king. The revenue it generates, regardless of whether it is distributed via ad-supported, "free-to-air" broadcasting, pay television or any other model, dwarfs that of other content types. Telcos and other
communications service providers looking to leverage their IP-based networks to offer
video as part of subscriber packages recognize the necessity and huge appeal this type of content has in winning and maintaining an audience share.
Similarly, mobile operators are finding that broadcast programming is the key to thriving in an increasingly competitive landscape. As growth rates from pure voice traffic flatten, they are introducing data applications, not the least of which are videos of popular broadcast network programs. Hence "mobile TV" is already proving to be a promising ARPU generator for mobile operators, with several million subscribers to such services worldwide.
Beyond the ARPU increase, mobile distribution of broadcast programming offers such new business opportunities as targeted advertising models. It's not surprising that incumbent operators are investing in
infrastructure to meet the consumer expectation for "content anywhere, any time on any device."
WiMAX is emerging as one of the most promising
wireless networking technologies designed to meet this demand. However, broadcast-quality video is a
bandwidth hog. As an IP-based network,
WiMAX faces inherent scalability problems. Each new customer requires more bandwidth, connectivity sessions grow longer and applications such as video require ever more capacity. Serving thousands of such individual "unicast" streams becomes expensive, and there is a seemingly inevitable decline in quality of service at periods of peak demand.
One way to avoid these issues, and take full advantage of WiMAX to meet consumer demand and operator interests, is to implement hybrid broadcast/multicast architecture. This type of
architecture is economically feasible because TV viewers tend to aggregate around "peak" viewing times: Despite the huge explosion in the amount of content now available on many networks and the inevitable fragmentation of audiences, in most markets, the bulk of TV audiences are largely served by five to ten major channels or networks.
This is true of fixed TV viewing and is likely to be the same with mobile, with the channels or networks meeting the demand for appropriately produced programming directed at commuting periods and other times in the day or week when mobile viewing is likely to be popular. A WiMAX TV broadcast/multicast solution enables operators to offer the most popular mobile programming at quality reception over predictable bandwidth and without any risk of congestion or contention during these peak-viewing periods.
In addition to nationwide or regional TV broadcasting, WiMAX TV also enables local content insertion and "micro-broadcasting" " the efficient delivery of content within restricted areas during popular sports events or concerts, or within airports, campuses or hospitals.
While viewing habits do tend to aggregate around certain predictable times, and audiences tend to gravitate en masse toward certain shows or programs, the portable nature of mobile TV means there will be a demand for individual streams and so-called niche or long-tailed content. Meeting this demand requires using a mix of broadcast,
multicast and unicast technologies.
Typically, this is done by broadcasting the most popular TV channels on bandwidth that is set aside and efficiently managed through dynamic multiplexing. Other TV channels are multicast based on the demand in each particular cell, while interactive services and niche content are serviced over unicast links. How these various services are packaged and sold to the viewers will evolve over time as the market emerges.
Making this hybrid approach to mobile video delivery successful involves not just the use of a WiMAX network itself, but the implementation of an architecture specifically optimized for WiMAX-based mobile video delivery. It is this type of architecture that can transform a typical WiMAX network into a WiMAX TV network.
An optimized WiMAX TV architecture is based on the Multicast-Broadcast Services (MBS) specification, which is part of the Mobile WiMAX (802.16e) standard. MBS supported by Mobile WiMAX (802.16e) leverages the most successful features of such technologies as DVB-H, DVB-SH, MediaFLO and 3GPP E-UTRA. It offers high data rates and coverage using a Single Frequency Network (SFN); a flexible allocation of radio resources; low mobile-station power consumption; support for datacasting in addition to audio and video streams and fast channel-switching.
The Mobile WiMAX Release-1 profile defines a toolbox for initial MBS service delivery. The MBS service can be supported by either constructing a separate MBS zone in the DL frame along with unicast service (embedded MBS) or by dedicating the whole
frame to MBS (DL only) for standalone broadcast service. MBS can be accessed when MS is in idle
mode to allow low MS power consumption. The flexibility of Mobile WiMAX to support integrated MBS and unicast services enables a broader range of applications. [1]
As this architecture is fully IP-based, it enables operators to use standard network and headend components, as well as their existing terminal applications. A complete infrastructure overhaul or rebuild is not necessary. In addition, the architecture is scalable over a practically unlimited number of users, flexible in content trafficking, and centrally managed and monitored.
The Single Frequency Network (SFN) architecture brings an additional gain of several dBs in the radio channel, thus improving reception quality. "Time-slicing" technology, successfully implemented in DVB-H and other broadcast standards, increases the lifetime of the terminal's battery by receiving the content in short bursts, rather then continuously. The Inter-bursts Forward Error Correction (iFEC) " developed by UDcast -- ensures perfect video quality under difficult propagation conditions, making short reception blackouts totally invisible to end-customers, such as when they are passing under a
bridge or tree.
While developing WiMAX TV architecture may not involve a heavy infrastructure upgrade, it is necessary to integrate software to manage the network's operations. UDcast has recently developed three software modules designed to meet this need including a WiMax TV Manager, which ensures the management of the entire WiMAX TV network, as well as the integration of the broadcast/multicast system with content sources, service protection and interactive services. Other
software modules include the WiMAX TV ASN/MBS (Mobile Base Station) Module and the WiMAX TV Base Station Module. The MBS module implements the core functions of our WiMAX Multicast-Broadcast Service
Controller and ensures the correct level of synchronization of the base stations for SFN operation, plus Inter-bursts Forward Error Correction (iFEC), intra-BS handover and content time-slicing. The WiMAX TV Base Station Module enforces SFN broadcasting and time-slicing and executes procedures for local content adaptation or injection, enabling geographically addressable content distribution.
These modules demonstrate that it is feasible to use WiMAX to deliver broadcast-quality programming to mobile devices. Harnessing the power of WiMAX to enable such a service offers numerous benefits to players across all segments of the industry.
IP and telecom infrastructure providers, for example, can use it as revenue-generating extension of their existing WiMAX solutions. Similarly, broadcast TV providers can use it as an innovative WiMAX
extension to their existing broadcast operations, or as a direct television distribution channel to the fast-growing community of WiMAX users.
Even though new applications and models won't be discovered until operators and other users began to implement WiMAX as a mobile video delivery tool, there are emerging applications and business models for WiMAX TV today. Many operators already have the existing network infrastructure to do this " they just need to embrace the technology in order to leverage it to its maximum, revenue-generating potential.
