Some of the RF topics I've covered this year may seem distant from broadcasting, but as broadcasting moves from analog technology to digital, broadcasters can take advantage of some of the new wireless data transmission options. These technologies have already influenced electronic newsgathering and will have a greater impact as broadcast auxiliary spectrum becomes scarcer. Digital TV broadcasting to small screens on handheld devices using MPEG-4 compression is gaining attention -- using broadcast spectrum in Asia and parts of Europe and the cellular data network in the U.S. As this holiday week is light on RF news, I decided to focus on some of the RF trends of 2003 and occasionally venture a guess as to what 2004 will bring. I'll include any current RF news from this week in next week's report, along with the usual bi-weekly U.S. DTV status update.
The Iraq war showed how wireless data communications could be used to provide real time video from remote locations under extreme circumstances. More efficient video compression technologies allowed broadcasters to use existing satellite telephone data links and small, portable terminals. Demand for higher speed data access is driving development of new satellite systems for providing connectivity from any location on earth.
Two interesting areas I've been tracking in RF Report are Ka-band and 2 GHz satellite systems. Both technologies have gotten off to a slow start, but I expect to see development accelerating in 2004.
Ka-band satellites offer the opportunity for high-speed two-way data access from very small terminals. Communications Research Centre Canada has been working with manufacturers to develop portable terminals for Ka-band access. A paper, Evolution of Portable Ka-band Terminals at CRC
, shows how the technology has progressed in the last 10 years. The third generation Ka-Pak terminal was designed for broadband multimedia applications, including newsgathering. The paper shows a typical configuration capable of 512 kbps data rates (much more than that available from the Immarsat terminals used in covering the Iraq war).
Eutelsat has rolled out SKYPLEX DATA, "the world's first broadband satellite network to couple on-board satellite multiplexing (SKYPLEX) with high power Ka-band frequencies." A news release
said this allows small terminals to communicate with each other without the need for an on-ground hub. A 90-cm terminal with a two-watt amplifier costs less than 4,000 euros. Applications include LAN-to-LAN interactivity for file transfers. The system can also be used for transmitting MPEG-4 television channels and broadcasting DVB/MPEG-2 television.
The Eutelsat system SKYPLEX data service will use up to four Ka-band transponders on the HOT BIRD 6 satellite at 13 degrees East.
U.S. broadcasters should have similar options. EchoStar has Ka-band transponders on the EchoStar IX/Telstar 13 satellite at 121 degrees west Longitude (See RF Report for August 18, 2003
). In the September 15, 2003
issue, I reported on Rainbow DBS Co.'s applications for five Ka-band satellites at locations ranging from 62 degrees to 129 degrees West Longitude. If the satellite operators allow broadcasters to access the satellites from portable terminals, these satellites could provide a low-cost option for digital satellite newsgathering, with the extra benefit of two-way data communication back to the newsroom.
The plans for the 2 GHz mobile satellite service (MSS) spectrum are less clear but could offer the potential for "handheld" low data rate DSNG if the terminals match the size of current L-band systems. The FCC has also opened up these frequencies for terrestrial wireless applications, which would increase service availability in urban areas where satellites might be blocked.
There is another option, however, for digital newsgathering in urban environments. It involves the use of the unlicensed national information infrastructure (U-NII) spectrum at 5 GHz. The FCC recently expanded the spectrum available at 5 GHz. One or more broadcasters could establish 5 GHz wireless networks at frequently used news locations for communication with the newsroom and for transmitting digital video. 5 GHz systems are available to support data rates up to 108 Mbps, although as data rate increases, the range of each wireless data transceiver decreases. Solectek recently announced a new inexpensive 5 GHz system that seems ideal for this. See the Solectek web site
for more details.
If you don't want to bother putting in your own wireless network or fussing with satellites, another option may be as close as your cellphone! Wireless Internet service is currently available over most of the country from AT&T, Sprint, Verizon and others at data rates up 133 Kbps. While this is too slow for most ENG applications, the next generation of services currently being rolled out in some markets offers data rates over 300 Kbps. At these data rates, with efficient MPEG-4 encoders, it is possible to transmit live video with quality many would consider acceptable. These higher speed wireless networks should become more widely available in 2004. Of course, if the edited news story you want to send back to the newsroom exists on a laptop, there is always the Starbucks option with high speed Internet access available over WiFi links at most of its coffee shops. While WiFi supports up to 10 Mbps, my very limited experience with Starbucks indicates 1 Mbps is probably the fastest real data rate you should expect.
As new wireless options become available for data, I'll report on them here. Now that it is relatively easy to put video and audio on a TCP/IP link, don't overlook these options for newsgathering.