Future-Proofing DSNG Solutions
by David Shamir
SNG became popular with broadcasters as a replacement for microwave technologies because of its extended geographic reach and potential for supporting broader and deeper reporting of key local events. It also enabled timely coverage of global issues, with the technology’s pioneering use often bringing television viewers fresh images from war-torn areas of the world. With the industry wide shift to digital technologies, DSNG increasingly became a mainstream means of delivering SD content.
Designed expressly for mobile trucks, SUVs, and flyaway packages, highly integrated DSNG solutions combine encoding, modulation and upconversion in a compact footprint and lightweight package ideal for news gathering applications requiring flexibility, responsiveness, and maneuverability. In addition to saving space, the integration of these capabilities also allowed for a higher level of interoperability, with less dependence on the operator to manage bit rates and other parameters. The development of sophisticated DSNG systems with built in multiplexing capabilities and telemetry served to simplify setup and transmission tasks so that journalists in the field could manage delivery of broadcast-quality MPEG-2 content without a great deal of technical expertise.
The emergence of HD broadcasting as the new norm made it important even for smaller broadcasters to look at ways of acquiring HD footage for inclusion in their newscasts or other programming. However, while MPEG-2 compression can be used for satellite-based delivery of HD content, the very high bit rate needed to encode HD content in turn requires a higher space segment on the satellite. As a result, it costs far more to deliver MPEG-2 HD content to a central station, studio, or any other location than it would to deliver MPEG-2 SD content to that same site.
The introduction of H.264 technology, also known as MPEG-4 Part 10, and the development of DVB-S2 standards have changed the face of satellite newsgathering. As broadcasters and other content providers seek effective ways of distributing high quality content, and HD content in particular, these technologies have enabled much greater efficiency than was possible through conventional SNG approaches.
The advanced MPEG-4 H.264 video codec was developed to address the problem of encoding efficiency, and this standard can reduce bit rates by 50 percent and significantly lower the cost of transmitting HD content via satellite. Broadcasters implementing H.264 encoding thus stand to realize substantial savings in capital and operational expenditures.
MPEG-4 H.264 technology presents a great opportunity for relatively economical HD delivery, enabling broadcasters to broaden their high-value premium offerings with the introduction of HD channels. Encoders on the market today offer broadcasters high-quality video at a much improved bit rate, with the option to work in a low error, low-latency mode when required for two-way live interviews and similar real-time interactions. This flexibility provides an optimal balance of image quality and transmission costs. Broadcasters can provide their viewers with engaging live reporting from the field while maximizing their use of satellite bandwidth.
The emergence of DVB-S2, an enhanced version of the DVB-S standard traditionally used for SD broadcasting over satellite, further adds to the efficiency of HD delivery. Developed around the same time that the H.264 video codec entered the market, DVB-S2 offers video compression and subsequent data rate improvements that reduce bandwidth consumption by another 30 percent.
The DVB-S2 specification yields two critical benefits: greater resistance to noise, which in turn leads to better spectral efficiency, and more bits per hertz compared with earlier technology. The resulting overall bandwidth savings enable broadcasters to transmit HD content via satellite using roughly the same bandwidth once required to deliver the same broadcast in SD using the DVB-S standard and MPEG-2 encoding.
The combination of MPEG-4 H.264 encoding and the DVB-S2 specification delivers enormous cost savings in the transmission of high-quality HD content. Taking advantage of these cost savings, leading North American satellite providers already have migrated to DVB-S2 for uplink and downlink applications.
While not all broadcasters are directly constrained by the limitations of satellite-based transmission, any content producer today must be aware of how that content will be delivered downstream. Cable operators deliver HD content encoded as MPEG-2, and satellite operators offer H.264 to the home. As they migrate to H.264, then, broadcasters need to maintain the ability to encode in both MPEG-2 and MPEG-4 H.264 compression schemes.
A number of capabilities characterize current, cost-effective encoding solutions for point-to-point and point-to-multipoint satellite fix contribution, primary distribution, and DSNG from transportable uplink stations. Full support for H.264 HD/SD, as well as DVB-S/DVB-S2 technologies, provides broadcasters with the smooth migration path they need to continue handling SD video and to deliver sought-after HD content efficiently and at a high quality.
Versatile configuration options ensure that the broadcaster pays only for the functionality needed, and software-upgradeable systems make it easy to add or update features if those needs change. Intuitive menu-driven controls keep operation in the field simple, and automatic detection of stream type and format, either SD or HD, helps to save time and reduce the need for manual intervention. Advanced encoding solutions also allow broadcasters to encode at a 4:2:0 profile when video will make just one hop prior to arriving at its intended destination, or at a 4:2:2 profile when more robust chroma components are required, as when video makes multiple downstream hops and is repeatedly decoded and re-encoded.
DSNG applications have come to include transmission of data along with video, and today’s encoders provide low-speed data broadcast and high-speed multiprotocol encapsulation (MPE). MPE-enabled encoders can accept inputs from external PCs, encapsulate that data into the broadcast stream, and broadcast either simultaneous to the broadcast stream or as a separate piece to the receive site, where data is de-encapsulated and delivered to the server.
To support a rising demand for IP contribution, encoders can be configured to deliver IP-based content as a main link over satellite or as a backup. Because IP delivery can be plagued by packet loss and other factors that threaten the reliability of the link, added tools such as forward error correction (FEC), typically performed according to the Pro MPEG specification, and dual Gigabit Ethernet outputs help to ensure that the signal is secure. With this built-in functionality, a single unit can provide a satellite feed and a main feed IP backup, which in turn has its own backup for dual redundancy. This type of one-box solution saves money, simplifies operations, and frees up space within the mobile unit.
The new generation of encoding solutions supports the broadcast industry’s shift toward HD newsgathering. While many broadcasters have yet to make the move, the industry’s transition already has begun. An investment in advanced, future-proof DSNG solutions can ease the burden on reporting and technical staff, reduces expenses associated with satellite transmission, and paves the way to more sophisticated and compelling news broadcasts.
About Scopus Scopus offers a range of solutions equipped with functionality for the broadcaster planning for MPEG-4 H.264 encoding and HD newsgathering. The company’s UE-9216, UE-9217, and UE-9318 DSNG MPEG-2 encoding platforms provide excellent picture quality and enable a cost-effective transition to H.264. The company’s UE-9818 DSNG platform is a H.264 SD/HD DVB-S2 encoder/modulator/upconverter combination ideal for multichannel mobile transmission applications in which high video quality and optimal bandwidth use are critical.
Scopus offers a range of solutions equipped with functionality for the broadcaster planning for MPEG-4 H.264 encoding and HD newsgathering. The company’s UE-9216, UE-9217, and UE-9318 DSNG MPEG-2 encoding platforms provide excellent picture quality and enable a cost-effective transition to H.264. The company’s UE-9818 DSNG platform is a H.264 SD/HD DVB-S2 encoder/modulator/upconverter combination ideal for multichannel mobile transmission applications in which high video quality and optimal bandwidth use are critical.Scopus offers a range of solutions equipped with functionality for the broadcaster planning for MPEG-4 H.264 encoding and HD newsgathering. The company’s UE-9216, UE-9217, and UE-9318 DSNG MPEG-2 encoding platforms provide excellent picture quality and enable a cost-effective transition to H.264. The company’s UE-9818 DSNG platform is a H.264 SD/HD DVB-S2 encoder/modulator/upconverter combination ideal for multichannel mobile transmission applications in which high video quality and optimal bandwidth use are critical.
About the author David Shamir is Scopus' product marketing manager for Scopus’ family of encoder products. David received his BS in Electronics Engineering from Tel-Aviv University.