Increases in file sizes (due to the transition of SD to HD) and the number of these new media outlets have combined to place additional emphasis on what transport methodologies provide the most efficient and most cost-effective means for content owners to distribute their content. Sending compressed and uncompressed HD is a clear, "no turning back" moment that will drive the shift from satellite transport to terrestrial IP delivery.
Satellite transport is clearly applicable for two distinct operations. For multicasting-when the same file needs to be sent to many locations and at the same time-satellite transmissions may be the only acceptable methodology to achieve these simultaneous transmissions. There is no equivalent within the terrestrial IP domain. Instead, multiple unicast transmissions or a cascading method of transmissions can be utilized. Depending upon the number of locations, aggregate payload of content, and time to delivery requirements, terrestrial IP delivery may offer an alternative to satellite transmission for these types of events.
As well, for real-time programming, when content exists only as a media stream and not as a single or a series of closed files, satellite usage is justified.
However, the adoption file-based acquisition systems (disk-based and solid-state based cameras) and the resulting file-based workflows have also meant that digital distribution methods are being put in place. The result is that an increasing amount of file transfers are occurring over terrestrial IP networks. The return on investment (ROI) to support a movement from satellite to terrestrial delivery become quite clear, especially when there is a requirement for HD content.
For example, based on real-world examples, using satellite to support HD distribution as opposed to SD distribution equates to approximately a 200% increase in costs. In fact, terrestrial IP delivery is 80-100 times less expensive than satellite delivery for locations that are 100 or fewer in number.
Further, there is the issue of reliable transfers that must be examined. Satellite technology can be interrupted by a variety of environmental conditions. It is not unusual for weather patterns to affect the reliable transfer of content. Rain, wind, clouds, and swirling sand storms have been associated with interrupted satellite transmissions. Such environmental issues are not applicable to terrestrial IP delivery.
Most networks are only growing in capacity. The real pressure being put on links for contribution and distribution has to do with arbitration controls. When more people are contending for finite network resources, what methods will be put in place to ensure that the most important files arrive before files of lower importance? What real-time bandwidth controls exist? How are security policies enforced? These are just some of the issues that become critical to understand and to address.