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Store and Forward Video

By Michael Murrie, TBS contributing editor

The Global Communications Talking Head GCS-750 Video Phone

The Hughes RBGAN satellite IP modem with antenna lid weighs 1.6 kg and measures

This column introduces a new TBS feature—a regular review of technical advances in the satellite television field byMichael Murrie, professor of journalism and video production at Pepperdine University. Murrie writes regularly about television news technology for various professional and trade publications, especially Communicator, published by the Radio Television News Directors Association.

The expensive, unwieldy production tools of television news seem to finally be yielding to the efficiencies of digital video. Small DV camcorders with three CCDs (charged coupled devices, light sensitive computer chips) priced at a few thousand US dollars create electronic images with quality that rivals the Betacam camcorders of a decade ago that cost ten times as much. Off-the-shelf computers including laptops edit video that rivals videos created by post-production facilities costing fifty times as much a decade ago. Now innovations in signal conveyance and compression offer more ubiquitous, efficient, and economical alternatives to satellite news gathering (SNG) with bulky uplink kits or vehicles.

These innovations have been available for several years, but television journalists in large numbers only used them seriously since the Iraq war of 2003.

Perhaps most significant are the store-and-forward systems for covering vast regions with uncertain telecommunications infrastructures. These systems combine the economies of compression and computer editing to convey video using nearly any telecommunication means available even if land phone lines or broadband satellite transponders are unavailable. The scalable store-and-forward systems can use satellite phones, Internet connections, and even wireless to convey video. The bandwidth of the method simply changes the time required to convey the video.

Sometimes known as laptop news gathering (LNG) or digital news gathering (DNG), typical systems start with a digital video camcorder or videotape player linked to a laptop computer or other portable computer to ingest and edit video. The resulting edited video file is transmitted via the most appropriate telecommunications link to another computer or video server on the receiving end. Its decoder converts the data back to audio and video for recording or display. The transmission time depends on the size of the file and the bandwidth of the communication link. Some vendors have proprietary boxes for encoding and transmission and for reception/decoding. Transmission by satellite phone requires a transmission device. Common compression methods include H.320, MPEG-1, MPEG-2, MPEG-4, Windows Media 9, and Quicktime.

The advantages of store-and-forward systems include flexibility and low costs. Disadvantages are limited bandwidth, format confusion, and sometimes transmission costs. Because these advantages and disadvantages often reflect two or more dimensions of the same characteristic, let's examine them as they relate to the nature of the telecommunications services and equipment, the costs, and the nature of digital video. Also included is a short discussion of video phones and cell phones as conveyors of news video.

Telecommuncations

As mentioned earlier, the store-and-forward systems typically can be adapted to almost any telecommunications signal conveyance method ranging from POTS (plain old telephone service) to satellite phone services to Internet Protocol services such as Regional Broadband Global Area Network (RBGAN). The bandwidth of these services is improving as new services become available and enhanced, but they fall far short of the bandwidth of a conventional satellite feed. For example, RBGAN can convey up to 144 kbit/s per second as compared to the most efficient SNG transponders that send real time MPEG-2 video at about three megabits per second. More often the SNG rate is much higher.

Of course, the limited bandwidth of store-and-forward systems makes the transmission of video much slower than real time, with perhaps thirty minutes or more needed to transmit a one-minute reporter package, depending on the data rate. Any video transmitted live, usually by video phone, is small, of poor resolution, and has a slow frame rate, as was evident in much of the breaking news coverage of the 2003Iraq war.

Despite the disadvantages of narrow bandwidth, the advantages of using lower bandwidth telecommunications are ubiquity of service and flexibility of logistics. Land-based phone service is available in many parts of the world, but if unavailable, with appropriate equipment and service, satellite phone service is available from almost anywhere regardless of how remote or undeveloped.
Yet there are times when even the satellite phone telecommunications infrastructure becomes overburdened with traffic from certain parts of the world. Before the Iraq war in early 2003 there was "great trepidation about the competition for Inmarsat channels" among the networks as they made their war plans. Inmarsat addressed capacity issues by placing a backup satellite in service to handle the extra traffic. Bill Tracy, director of ENG for ABC News, said he was "pleasantly surprised with the results" (Murrie 2003).

RBGAN service is expanding in the Arab World and other nearby regions. It currently serves ninety-nine nations in the Mediterranean, Middle East, Europe, the Indian subcontinent, and North, Central, and West Africa. Just last month Inmarsat reached agreement with Net Iletisim of Turkey and Cerist of Algeria to broaden the marketing of RBGAN. Plans by Inmarsat and the European Space Agency call for extending BGAN service in 2005 to provide data service at speeds up to 432kbits/s.

The compact size of store-and-forward systems creates an independence of movement and political regulation. Often a news crew entering a nation must have special approval for satellite uplink equipment thus making the crew vulnerable to regulators and extraordinary fees or taxes. The store-and-forward systems attract less attention. They usually reside in a laptop computer. A RBGAN satellite IP modem including antenna is similarly sized typically weighing 1.6 kg and measuring less than 300 x 300 x 50 mm. Satellite phones typically have the same width and depth with a height of perhaps 150mm. SNG transponders are getting more compact now-they are comparable to large suitcases-but even the smallest measures 70 x 50 x 30 cm.

Cost Dimensions

The unique feature of the RBGAN service is that its charge is by data unit transmitted, typically $10 to $15 US per megabyte, according to Inmarsat. The connection can remain on and does not necessarily need to be re-established from the same transmission point. The user simply connects the modem to a laptop computer, points the antenna in the direction of the satellite and begins communication.

Rather than charge for data transmitted, conventional Inmarsat phone service charges by the minute regardless of whether data is transmitted. High speed GAN service of 64 kbit/s costs from $6 US per minute. Sometimes two or more channels are combined to produce higher data rates.
Given long transmission times, it's quite possible that just the transmission costs for sending a two-minute video story in real time via broadband satellite could be much less than taking an hour or two to send two minutes of video via a satellite phone.

Of course, hardware costs are much more for conventional SNG. Uplinks cost at least $100,000 US and often much more. Satellite phones and IP modems are much cheaper. RBGAN hardware expenses are even less, with a modem cost of less than $2,000 US. A GAN modem terminal tends to have more robust signal strength but costs $7,000 US. The cost of a videophone GAN terminal with a single channel of 64 kbits/s is $8,000 or with two 64 kbits/s channels $10,000 US. Store-and-forward software for a laptop computer starts at about $2,000 US as does the price of an appropriately configured laptop computer itself.

This brings us to another important point about the store and forward systems. Although the IP modems, satellite phones, and videophones are special items, the basic laptop that often contains editing and transmission software is off-the-shelf. Thus chances are good for repair, loan, or replacement in case of hardware failure.

Digital Video

Video on computers seems to come in an unending variety of formats, both proprietary and open. Fortunately, quality and efficiency continue to improve as vendors develop more systems that handle multiple formats. For example, the Livewire Digital M-Link platform for its Voyager Lite store-and-forward system incorporates video codecs such as Microsoft Media 9 and other derivatives of MPEG-4 while maintaining options to use MPEG-1 or 2. The laptop editor must have IEEE-1394 (Firewire) inputs to accept DV video. The editor must edit a high quality video file acceptable to the television system at the destination site.

Video Phones

Video phones offer field crews versatility and mobility to convey live video but do so at a slow frame rate and much less resolution than SNG uplinks. Compression methods are most often those employed for video conferencing such as H263. Usually the video phones use GAN ISDN service that is 64 kbits/s or paired circuits at 128 kbits/s. The arrangements usually include an IFB signal back to the video phone.

A few products are becoming available that promise better signals than those from videophones. For example, Quicklink's Live Broadcaster codec is scaleable so that it works from anywhere between 64Kb/s to 4Mb/s. Latency over the Inmarsat network is approximately one second.

Wireless Video

The BBC has recently started using 2.5G cellular phones from Nokia to deliver video from the field (Kerschbaumer, 2003). Video quality is comparable to a single channel satellite phone but can only be used for store-and-forward not live reports. A phone can store 128MB of data or about two minutes of audio and video. Transfer time is about 20 minutes for 70 seconds of video at only 15 frames per second and the highest resolution.

Implications

Store-and-forward systems and videophones extend the reach and presence of news organizations in the field. Just considering capital costs, for the price of one flyaway SNG uplink, a news organization can deploy several store-and-forward reporters each with a laptop, DV camcorder, and satellite phone and/or IP modem. These crews can go to more remote locations. Transmission costs may be higher, but they can operate more efficiently as one-person crews saving personnel costs. An SNG flyaway would usually require at least a technician and a reporter. With less bulky equipment the laptop news gatherers are more mobile and may be less vulnerable.
Over time, because of the economy and ubiquity of digital news gathering, more stringer material from more diverse locations may appear on news programs. If cell phone operators begin contributing video, the news gathering process will open dramatically. The BBC is already considering how to take new content from a new class of video stringers (Kerschbaumer, 2003).

A more open news gathering process, of course, raises concerns about the accuracy, fairness, and credibility of news video from stringers. What processes can be established to verify such video?
It's doubtful that the low-cost digital video from laptop journalists and cell phone users will soon replace SNG uplinks for live coverage. They will still be needed for higher quality, more complex news programs on location. Laptops and even cell phones are just additional tools that can be used to gather more diverse stories, more quickly from a broader range of sites. TBS

References

Cass, D. (2003) New compression technologies aid war reporting, save cash. Transnational Broadcasting Studies 10 (TBS 10). http://www.tbsjournal.com/Archives/Spring03/cass.html

Deshpande, R. (2003) MPEG-4 / DIVX Based Store-and-Forward System. http://www.broadcastpapers.com/sigdis/NewDelhiTVMPEG4DIVX-print.htm

Johnston, C. (23 April 2003) TV goes to war. TV Technology. (http://www.tvtechnology.com/features/news/n_TV_goes_to_war.shtml)

Ken Kerschbaumer. (22 Dec. 2003) "News Video Gets Mobile" in Broadcasting & Cable, Vol. 133 (51), p. 14

Murrie, M. (May 2003) "New Technology Brings Live Coverage of War in Iraq" in Radio Television News Directors Association Communicator, pp. 6, 8.
http://www.rtndf.org/trades/wartech.html