Part 1 of 2
After three years it was great to get back together with fellow engineers and exhibitors at the NAB Show in Las Vegas. Official attendance was more than 50,000 people but with the new LVCC West Hall and spread-out exhibits with plenty of meeting spaces, it was busy but not crowded. 

Like many attendees I spent time catching up with old friends. With the repack over, the focus shifted to launching ATSC 3.0 and that will be the main topic of my convention review, specifically analysis of ATSC 3.0 signals. 

Saankhya Labs
I looked for low-cost ATSC 3.0 receive devices such as USB tuners, excluding complete TV sets. New at the NAB Show were devices from Saankhya Labs in India. They are using a chip developed with Coherent Logic that can decode all DTV formats, including ATSC 3.0. 

The company does not sell directly to consumers but was showing a smartphone with a built-in ATSC 3.0 receiver as well as a dongle that will work with a smartphone with a USB port. (Fig. 1 shows the dongle in use receiving an ATSC 3.0 broadcast from Saankhya Labs’ low-power transmitter that will be offered for use as a low-power ATSC 3.0 booster.) Tolka also showed a dongle it plans to offer for sale to broadcasters. 

Airwavz
There were several products on display for analyzing ATSC 3.0 signals. The lowest cost options, both from Airwavz, remain the RedZone Receiver Plus (RZR-1400) and new TVXplorer 2.0 software, which was released at the show. TVXplorer 2.0 now includes the ability to decode and analyze Dolby AC4 audio as well as providing thumbnails of all the video streams with up to four concurrent PLPs. With the new version, the price increased to $2,595. The RZR-1400, which uses the Sony receiver chip, is $900. 

I think I was the first person to buy TVXplorer 2.0. I didn’t get it installed in my Windows 10 VM until after the NAB Show but had a chance to test it in Los Angeles. It worked fine, with both video and audio playing along with full details on all the tables and a service guide. 

The software comes with a lifetime license and development is continuing. I was told an update might support the Silicon Dust tuner, which would dramatically lower the cost of the package and help keep it competitive with the alternatives. The dongle and software are available on-line at https://redzonereceiver.tv/ or from Comark or Unisoft. 

Dektec
Dektec showed a new USB DTV tuner that is SDR-based, so it can handle multiple standards and looks like the Dektec USB universal DTV modulator. The device comes with basic software to decode ATSC 3.0 tables, but for a complete analysis, it needs to be paired with software like Triveni’s StreamScope XM or Stream Verifier. 

The software does not currently include a spectrum analyzer but since the receiver is SDR-based it shouldn’t be too difficult to add that in the future. The cost is under $4,000. 

ENENSYS
I knew ENENSYS was one of the leaders in developing ATSC 3.0 scheduler and gateway products but didn’t learn about their range of ATSC 3.0 monitoring equipment until I visited their booth at the show. Their “REFEREE3,” introduced at the last NAB Show in 2019, provides ATSC 3.0 signal characteristic measurements (useful for field tests) as well as stream analysis down to the frame level. 

For more detailed measurements at a fixed location, they have the “Edge Probe.” I don’t have room to list all the features here. See www.test-tree.com/product/atsc-advanced-monitoring-probe/ for details on it and other ENENSYS monitoring products. 

IPguard
Another item that caught my attention was the IPguard, which can monitor ATSC 3.0 STL-TP streams and switch to a backup in case of a failure. The switch depends on a flag inserted in the stream, which I hope will be supported by other scheduler/gateway vendors. 

Promax
All the portable measurement devices I’ve described so far require a laptop or computer for operation. Promax was showing a new standalone portable in their Ranger line that offers ATSC 3.0 reception, including video and RF constellation displays and a spectrum analyzer. With tabs on the display, you can view table content and signal characteristics. 

I was told it will support LDM, which could come in handy for field measurements. It also includes an Ethernet port for monitoring IP streams and logging data on a laptop. Pricing had not been set but was expected to be slightly above the price of their other Ranger units, which would put it in the $10,000 range. As of May 1, no data on this unit was available on the company’s website (promaxelectronics.com).

Triveni Digital
Most readers are familiar with the Triveni StreamScope XM ATSC 3.0, which has become the standard for detailed ATSC 3.0 signal analysis. 

They now offer a lower-cost product, the Stream Verifier, for around $4,000, which provides basic data on the ATSC 3.0 stream and a quick check on the quality and compliance of the stream. It needs to be paired with a compatible ATSC 3.0 receiver such as their dongle, one of the Dektec receivers or the Avateq receiver. 

Avateq
Avateq had their line of ATSC1.0 and ATSC 3.0 monitoring receivers on display, including the AVQ-200. Avateq is now offering STL-TP analysis in their products. 

One thing to keep in mind when considering ATSC 3.0 monitoring is whether the device or software will continue to be able to display video and audio after broadcasters begin encrypting streams. While all the tables and signal characteristics should remain available (unless the device has a key from A3SA, the ATSC 3.0 security authority), they will not be able to display encrypted content. 

Tablo
Preparation for encryption caused Tablo to delay the release of their ATSC 3.0 gateway and DVR product until they could modify the hardware to support the keys. Since the key has to be in secure storage it could not be offered as a firmware update. 

The introduction of digital rights management should not be an issue for most if it can be handled the same way NetFlix, Hulu and other streaming services protect their content. If implementation is more onerous, then it could slow the adoption of ATSC 3.0 by limiting the development of new ATSC 3.0 devices and the options viewers have to receive ATSC 3.0 broadcasts. 

In Part 2, I’ll have more on my experiences with the TvxPlorer 2.0 program, using the HDHomeRun ATSC 3.0 gateway in a portable configuration; a description of the NAB session dealing with drone measurement of antenna patterns and RF system heating; and some transmitter- and antenna-related NAB Show news I didn’t have room to include here. 

As always, I welcome comments and questions. Email me at dlung@transmitter.com. I try to answer all emails promptly, but if I’m busy and the email gets buried, I might miss it. If you don’t get a response within a week or so, email me again.

ALEXANDRIA, VA.—Now that broadcasters soon plan to deploy ATSC 3.0, there needs to be test equipment and procedures to ensure accurate transmission. Manufacturers are working to develop gear that will measure the new parameters that are important to maintaining a clear ATSC 3.0 signal.

One feature of ATSC 3.0 that pushes the limits to measure reliably is its layer-division multiplexing (LDM), one of a few techniques to pack as much data into the standard as possible. However, being a state-of-the-art standard makes ATSC 3.0 a state-of-the-art measurement challenge.

“ATSC 3.0 is a very practical standard that gathers the most recent coding techniques and experiences of its predecessors,” said Vladimir Anishchenko, president and chief technology officer for Ontario, Canada-based Avateq Corp., manufacturer of the AVQ1022 RF signal analyzer. “That is why the challenge is not in a particular measurement but rather in a number of measurements creating a whole picture of the signal quality.”

Anishchenko noted the difficulty that ATSC 3.0’s LDM technology adds to the mix.

“Compared to MER/SNR measurements in the DVB/ASTC 1.0 standard not using the LDM technique, physical layer pipe [PLP] MER measurement is not a trivial task for ATSC 3.0,” he said. “In ATSC 3.0, actually two PLP MERs exist in a case of LDM: a) MER of PLP calculated over a superimposed core and enhanced PLPs, and b) MER calculated for LDM ‘decomposed’ PLPs, i.e., for each LDM super-positioned PLP.”

WHERE BROADCAST, BROADBAND MEET

Although digital broadcasting has existed worldwide for several decades, ATSC 3.0 is something of a departure from older digital standards. That has an effect on the way it is tested and measured.

“ATSC 3.0 is at the meeting point of broadcast and broadband, more tailored to viewers’ needs but much more challenging for the operators,” said Jean-Pierre Thomas, test and monitoring director for France-based Enensys, a manufacturer of ATSC 3.0 gateways and SFN synchronization systems. “Permitting both indoor and mobile reception for the same TV channel implies configuring an LDM-based transmission, meaning the combination of a basic and robust QPSK with a complex but high-quality NUC 256QAM. The other main topic, such as multi-PLP, is something DVB-T2 operators are already familiar with, but is now adapted to ATSC 3.0.”

Broadcasters have seen a shift to IP for years, and ATSC 3.0 continues that trend. Components that used to be discrete blocks of hardware are disappearing in the IP world, which has implications on test and measurement.

“The move to an all-IP infrastructure is also a challenge, with software-based and virtualized major components such as a gateway (scheduler) or even a modulator,” Thomas said. “With ATSC 3.0, it only uses hardware parts when necessary, such as when dealing with analog signals.”

To accurately measure ATSC 3.0 signals, “first you need to know whether you are receiving a good-quality signal, therefore you need to measure the usual RF parameters,” Thomas said. “[That includes] the signal level of course, but also the MER and BER values, which should be measured for every PLP received, as they provide the quality of the modulation.

“If not, when a frequency interleaver is used these values can be estimated based on the L1 (basic/detailed), as the pilots are spread over the spectrum,” Thomas added. “These measurements should be done in the field, as seen by a common receiver. The operators can then generate coverage quality maps, logging RF measurements with GPS location.”

ATSC 3.0 is a very dynamic environmen that puts complex demands on a test environment, said Johan Craeybeckx, business line director at Eurofins Digital Testing International in Belgium.

“In order to ensure the accuracy of a device under test, Eurofins Digital Testing has built an ATSC 3.0 broadcast environment allowing tests to be created in a real-world and reproducible way,” Craeybeckx said. “When there is a particular challenge to measure, Eurofins Digital Testing has designed specific hardware to make measurements, such as a hardware device that measures the accuracy of audio-to-video synchronization at frame-accurate levels. This reduces the time and costs associated with validation and conformance to ATSC 3.0 standards.”

ONGOING ACCURACY

An ongoing concern for test systems is their accuracy over time. With ATSC 3.0 needing novel and highly precise measurements, what is the probability that test equipment will remain calibrated and continue to produce accurate results?

“I am not sure if the reference is to the crystal in the RF card or clock on the analyzer,” said Ralph Bachofen, vice president for sales and marketing for Triveni Digital. “As for the clock on the analyzer, it can be configured as PTP or NTP on Linux, or NTP on Windows. The crystals on the RF receiver cards are highly accurate and don’t really need recalibration these days.”

Not all manufacturers suggest a hands-off approach. “Although our gear is thoroughly calibrated at the factory to provide reasonably accurate power and time-related measurements, the accuracy might degrade mainly due to the gear component aging and parameter variations,” said Avateq’s Anishchenko. “We would recommend recalibration each year.”

Software measurement tools depend on the timing of the devices they run on, which in turn are connected to networks that use precision timing systems.

“A lot of solutions will actually be software-based, or virtualized,” Thomas said. “The gear will then rely on standard or professional-grade servers provided by third-parties. As for the RF measuring gear, after purchasing the equipment, it is usually standard to recalibrate the device once every other year, in order to prevent time and weather-induced artifacts on the main components.”

The transition to 3.0 from 1.0 is moving slowly, with just a handful of stations committed to the new standard. Bachofen recommends simultaneous testing of both standards to keep the broadcast neighborhood clean.

“In the early deployment phases, it is important to analyze all demarcation points in the broadcast chain to minimize anomalies and issues that might arise,” he said. “We believe that during the simulcast timeframe, it is imperative to analyze both the ATSC 3.0 and ATSC 1.0 standards simultaneously, and possibly on DMA-wide scale, as channel sharing is required in most scenarios.”

As Bachofen points out, ATSC 3.0 is about as different from ATSC 1.0 as ATSC 1.0 was from analog. “ATSC 1.0 is an MPEG transport stream over 8-VSB, so that is a completely different standard compared to ATSC 3.0,” he said. “DVB has some similarities as part of the physical layer based on COFDM. However, everything else in ATSC 3.0 is different and fortunately IP based.”

This means that there will be new testing gear and procedures, and it may take time for the best practices to sort themselves out. In the meantime, some familiar companies and some less-familiar ones are making the gear needed to ensure that ATSC 3.0 transmissions are delivering pristine signals to viewers.

For a comprehensive source of TV Technology’s ATSC 3.0 coverage, see ourATSC3 silo.

PRINCETON, N.J.—Triveni Digital and Avateq are entering into a business marriage, and as often happens in marriages, a name change is in order. The AVQ1020 ATSC 1.0 and AVQ1022 ATSC 3.0 ActiveCore RF layer monitoring receiver and signal analyzers from AvaTeq have been rebranded to fall under Triveni’s StreamScope brand as StreamScope XM RF.

The AVQ1020 and AVQ1022 systems were based on an ActiveCore platform and could monitor and analyze digital broadcasting standards, including proprietary modulation schemes like ATSC 1.0 and ATSC 3.0. Now as StreamScope XM RF, the system can be used in conjunction with Triveni’s StreamScope XM MT quality assurance and StreamScope EM-50 enterprise manager systems to detect, isolate and resolve problems that degrade broadcast services across transmission layers, including RF, MPEG, and IP, in ATSC 1.0 and ATSC 3.0 architectures. This will also offer compliance with federal regulations like the CALM Act and closed-caption requirements.

 Triveni and Avateq plan to collaborate on future integrations with the StreamScope line of products, according to Triveni’s press release.

Triveni and Avateq will both showcase the StreamScope systems at their booths, 644 and 735 respectively, during NAB Show New York.