Technology seminar: ENG
In all things, change is inevitable, but the pace at which electronic newsgathering technology is evolving is unprecedented — and, to a degree, unpredictable — for this corner of live television. At NAB2006, at least three significant technology trends emerged that are reshaping how news will be gathered and transmitted to the local station. They include:
- the ongoing work by Sprint Nextel to relocate broadcasters to 12MHz digital channels in the 2GHz band,
- the development of wireless camera transmitters capable of supporting high-definition news and, sports acquisition in the field, and
- the transmogrification of video from a signal to a digital file, allowing video to play in the IP space with all the advantages of the Internet.
It's become clear that this treatment of video as files, which can be sent via FTP across wireless Internet broadband service, adds a pinch of unpredictability to the ENG recipe. While few would argue that in the near term IP file transfer will replace traditional point-to-point microwave as the preferred method of backhaul, it is becoming apparent that today, the technology offers a powerful means to supplement traditional ENG and in the future, may play an even greater role.
The FCC-mandated Sept. 7, 2007, deadline for the conversion of ENG operations from analog to digital and relocation to 12MHz-wide channels between 2025MHz and 2110MHz weighed heavily on the minds of many at NAB2006. It appears the FCC, Sprint and the industry could not foresee the obstacles currently impeding relocation progress. Many on the show floor questioned whether the 31.5 months allotted for the relocation would be sufficient. However, Sprint is sticking to its assessment that the job will be completed on time.
Failure to hit the deadline won't be the fault of microwave equipment vendors. At least two, including RF Central, showed photographs of shelves at their facilities chocked full of new, compliant microwave radios and associated equipment ready to be rolled out once exchange agreements are reached between Sprint and the stations, groups and networks. The consensus on the floor identified several factors, including unanticipated layers of group and network management, an initial lack of understanding about the complexity of the task, complicated tax implications and cautious corporate legal counsel, as reasons for the unexpected delays.
Perhaps a harbinger of better news was an announcement from the ABC Owned Television Stations Group and Sprint just prior to the opening of NAB2006. The two have agreed to a template Frequency Relocation Agreement for each ABC-owned station and a Group Reimbursement Agreement covering the network's station group relocation-related expenses in the 2GHz relocation project.
Under the terms of the agreement, Sprint will pay for ABC's relocation-related expenses, including the acquisition of comparable equipment to operate in its new frequencies. One Sprint source expressed the hope that now that a large network has committed to a relocation agreement, other networks and station groups will accelerate their approval processes to avoid being the last on the relocation boat.
HD wireless cameras
Fresh off its use at the West Asian Games in Doha, Qatar; the Winter Olympics in Torino, Italy; and Super Bowl XL in Detroit, the Link Research LinkHD wireless camera system made its second NAB appearance this year. Exhibited in the Microwave Radio Communications (MRC) booth (both companies are owned by Vislink Communications), LinkHD L1403 delivered HD shots with only a 50-millisecond delay. The system uses the company's MPEG-2 encoder and a diversity reception system for reliability and performance.
LinkHD offers 1.95GHz to 2.7GHz or 3.40GHz to 3.58GHz operation and supports LMS-T and DVB-T modulation schemes and a variety of camera control options. LMS-T is an expansion of the standard DVB-T pedestal. It couples all of the advantages of COFDM with a single carrier using a widened channel bandwidth of 8MHz to deliver greater throughput.
At the Nucomm booth, the latest version of the CamPac made its NAB debut. The CamPac 2 COFDM SD/HD camera-back transmitter offers user-selectable MPEG-2 encoding supporting a low latency mode down to two frames, as well as an IPB frame mode that delivers a 30 percent improvement in image quality. The “B” mode designates higher performance compression and typically is associated with rack-mounted encoders from companies, such as TANDBERG Television and Harmonic.
CamPac 2 delivered live HD shots at 34Mb/s from the back of the Las Vegas Convention Center Central Hall, where the NAB-HD studio was located all the way to Nucomm's booth in the front of the same hall. Nucomm's new Newscaster DR digital COFDM diversity SD/HD receiver was used to receive the live shots.
The Newscaster DR offers DVB-T compliance at 6MHz, 7MHz and 8MHz channels and provides variable IF bandwidth from 4MHz to 16MHz in the 1.99GHz to 2.7GHz bands and from 4MHz to 24MHz in the 6.4GHz to 7.1GHz bands. It's no coincidence the specs match those of the CamPac 2, which offers operation in the 1.99GHz to 2.7 GHz and 6.4GHz to 7.1GHz bands. The CamPac 2 operates with DVB-T-compliant modulation in 6MHz, 7MHz and 8MHz channels and also supports COFDM operation in channel bandwidths from 4MHz to 24MHz. While the CamPac 2 is due to ship in July, a prototype has been used for coverage of NBA basketball and the America's Cup race.
No stranger to high-profile HD coverage of sporting events, the RF Central RFX-HD-CMT camera-mounted system transmitted wireless high-definition video from around the Central Hall to a Global Microwave Systems Messenger Smart Receiver with a Sencore decoder in the company's booth. Used last season during the NFC playoff games, the RFX-HD-CMT supports MPEG-2 encoding and comes with dual COFDM carriers. Typically, RF Central would match the wireless camera transmitter with an RFX-RMR-X6, but for the sake of simplicity at the show, the company used the GMS receiver.
The RFX-HD-CMT supports user-selectable 6MHz, 7MHz and 8MHz channels operating in 1GHz to 6Hz bands. Maximum RF output power is 200mW. The system can transmit a maximum range of between a quarter and half of a mile under typical operating conditions. However, in March, the company successfully linked a transmission from the RFX-HD-CMT through a helicopter a distance of 5mi.
Thomson Grass Valley also showed its new HD wireless camera system. The system is unique in that it uses JPEG2000 wavelet-based compression to deliver high compression efficiency and encoding latency in the one-frame range. The RF component of the new system uses a WiMax subset — 802.16 — to provide coverage of 3280ft with an optional roaming kit. Grass Valley's HD wireless camera system was designed to be used with the LDK 6000 series of high-definition cameras.
The fact that several vendors focused on HD wireless camera solutions at NAB2006 shouldn't be too surprising given the explosion in high-definition production of major — and even less than major — sporting events and the ongoing building boom in HD teleproduction vehicles.
Computers, data and file transfers
There has been digital video since the introduction of the D1 format two decades years ago, but only within the past few years have file-based systems, which leverage IT technology in a broadcast setting, brought the workflow efficiencies common in other industries to the domain of television.
For the past couple of NAB conventions, the concept of FTP file transfer via ENG transmission has been discussed and technology demonstrated. This year, at least two vendors — Microwave Radio Communications and Broadcast Microwave Systems (BMS) — brought deliverable systems to the floor.
The concept is simple: Encode IP traffic into the video data stream transmitted back to the station, giving journalists in the field the ability to FTP edited packages and B-roll. Couple this technology with a return link via microwave, a portion of a multicast DTV channel, wireless broadband Internet provider or even an EVDO cell phone network, and suddenly the newsroom extends to the ENG truck. Reporters can now operate in the field as if they were behind their computers in the newsroom reading news wires, writing scripts, editing footage, producing voiceovers and filling in lower-third templates.
BMS showed the Truck-Coder II (TC-II) media router, an add-on to its TC-II COFDM digital microwave system. The media router system consists of two parts: the Mobile Media Router that resides in the ENG truck and the Fixed Media Router at the receive site.
The Mobile Media Router system scales the IP throughput to the amount of available bandwidth. That means during a live shot, an FTP transfer of offline material can be scaled back, and when the standup is complete, it can be ramped up to allot the entire channel to the FTP transfer. A variety of data return options can be used with the TC-II Media Router system. At NAB2006, BMS held out EVDO cell service as a likely, viable solution.
Leveraging the power of IP wasn't confined to the TC-II Media Router in the BMS booth. The company also showed a couple of important enhancements to the TC-II COFDM microwave system: a simplified set-up menu structure and IP addressability. These allow station engineers to load presets into the TC-II or to make tweaks to it using BMS software running on a PC connected to the unit via Ethernet. Additionally, this approach relieves engineers of the time-consuming task of setting up each TC-II at the station individually. Rather, once operating parameters are established and saved on a PC, they can be transferred to multiple TC-IIs quickly and efficiently.
MRC demonstrated its IP solution in its booth with a link from an ENG truck parked between the Central and South Halls of the Las Vegas Convention Center. Using the MTX4000 ENG encoder-modulator, a live HD feed from the truck was transmitted using COFDM at 20Mb/s along with FTP traffic to approximate how the system could be used in the field to simultaneously transmit live video and support offline file transfer. With the MTX4000, ENG crews can allocate bandwidth to FTP transfer based on existing needs — less during live shots, more at other times.
MRC identified a number of wireless links that could be used for a return channel with the MTX4000 system. However, from a practical point of view, unlicensed wireless 900MHz LAN extensions and EVDO cell phone service appear to be the most viable. While 900MHz systems offer good propagation, the band is pretty congested; therefore, EVDO may prove to be the preferred technology for a return link.
A viable return link is critical to the adoption of this file transfer from the field because it allows dropped data packets to be re-requested and delivered. Without it, broadcasters couldn't have confidence that files were delivered intact and ready for use, obviating the promised benefit to workflow.
Fade to black
Data transfer also introduced a degree of unpredictability into what the ultimate shape of ENG will become post 2GHz transition. While the industry is hard at work completing inventories of microwave equipment and negotiating with Sprint, a few have begun to push the envelope with file transfer.
KRON chief engineer Craig Porter and BitCentral CEO Fred Fourcher presented a white paper at the conference on April 25 titled “Files to video journalists, a case study of organizational change At KRON 4 in San Francisco,” which revealed the station currently is testing a Bay Area WiMax network for possible live contribution from its video journalists. Running at 2.5Mb/s, the live shots will run over the WiMax connection from the carrier into the KRON building — staying in the WiMax network without being subjected to the public Internet — to protect contribution from latency. The WiMax service provider currently has 20 towers delivering coverage to the metro. Maximum distance from user to tower is 20mi, and the service provider sells full duplex data transmission from 1Mb/s to 7Mb/s and provides “a pilot carrier to establish a connection with the tower,” the white paper said.
As envisioned, a KRON video journalist would set up a 12in-sq flat antenna on a tripod and point it at a local tower. The WiMax system would automatically assign a channel to the video journalist for file transfer. According to the paper, because the video journalists in the field and the station share the same network, “it is possible to use this type of connection to contribute live video.”
Additionally, Inmarsat demonstrated its BGAN, a broadband global area network satellite system. It takes the concept of file transfer to its logical extension, offering broadcasters a way to contribute voice, video and data from 85 percent of the world's landmass over a broadband satellite network.
The KRON application and the promise of Inmarsat's BGAN satellite system demonstrate the growing importance of file transfer technology as forward-thinking broadcasters begin to experiment.
One day, this may transform the ENG landscape into something more akin to the World Wide Web than a dedicated point-to-point transmission system. When that will happen is anyone's guess. But one thing is certain: NAB2007 is likely to provide a clue.
Phil Kurz authors several Broadcast Engineering e-newsletters, including “ENG Update,”“HD Update,”“IPTV Update,” “News Technology Update” and “RF Update.”
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Phil Kurz is a contributing editor to TV Tech. He has written about TV and video technology for more than 30 years and served as editor of three leading industry magazines. He earned a Bachelor of Journalism and a Master’s Degree in Journalism from the University of Missouri-Columbia School of Journalism.