FCC Proposes to Reinstate Amateur Radio Service Fees

The FCC has proposed in an NPRM to impose license fees on Radio Amateurs.  I urge you to send your comments to the FCC arguing against the reinstatement of those license fees.

You may not be aware of the public good this service provides in times of emergency, as it has during the recent hurricanes.  The decrease of new applicants in recent years is not helped by this mercenary proposal.

You may also not know that amateur radio is often a leading developer of new technologies.  Just one example is the recent development of a low-cost vector network analyzer — the NanoVNA.  Originally developed by and for radio amateurs, this breakthrough device is now being used in the broadcast and other wireless industries, as written up by broadcast engineer Doug Lung in the last two issues of IEEE BTS Magazine and in TV Technology.

The NPRM can be found at FCC MD Docket No. 20-270Comments are due by November 16, 2020.

The ARRL will be filing comments, and their position can be found at this link; you may be interested to see my filed comments.

73’s,

Aldo, W2AGC

Modulation 101

Modulation is the process of imparting a signal, usually audio, video, or data, onto a high-frequency carrier, for the purpose of transmitting that signal over a distance.

Let’s take a carrier signal,  cos(ω_c t) and a modulating signal,  cos(ω_m t), where ω = 2 \pi f , and f is the signal frequency.

Amplitude modulation is simply the product of the carrier signal and (1 + modulating signal):

\displaystyle AM(t) = cos(ω_c t) \times [1 + cos(ω_m t)] ,

which multiplies out as: AM(t) = cos(ω_c t) + cos(ω_c t)\times cos(ω_m t) ] . A carrier modulated by a sine wave is shown in the following example.

Note that such a signal is relatively easy to demodulate: a simple rectifier and low-pass filter will recover the modulation from this signal, as you can visualize by “erasing” the negative portion of the signal and averaging over the remaining waveform.  Such a process is called envelope detection.

To analyze the composition of this signal, we take the trig product identity, cos(x)\,cos(y) = \frac{1}{2} [ cos(x-y)+cos(x+y) ], and apply it to the product term in AM(t), producing the following:

\displaystyle AM(t) = cos(ω_c t) + \frac{1}{2} cos(ω_c t - ω_m t) + \frac{1}{2} cos(ω_c t + ω_m t) .

From this, we observe an important aspect of the process:  amplitude modulation results in a signal composed of the following three components:

    1. the carrier signal, cos(ω_c t),
    2. a lower sideband signal, \frac{1}{2} cos(ω_c t - ω_m t),
    3. and an upper sideband signal, \frac{1}{2} cos(ω_c t + ω_m t).

By the way, the reason for the “1 + ” term in the modulation equation above is that it specifically generates the carrier component in the modulated signal. Without it, we would have the following Double-Sideband-Suppressed Carrier signal, which should make it apparent that we can’t use a simple envelope detector to demodulate; note how the envelope “crosses over” itself:

An analysis of modulation is aided by using a more complex modulating signal.  A ramp signal is comprised of a fundamental sinusoid and integer harmonics of that fundamental.  For illustration purposes, we will take an approximation that uses the fundamental and the next 8 harmonics. This modulating signal is shown below, as a function of time.

The spectrum of this signal, i.e., a plot of the frequency components versus level, is shown next; it consists of a fundamental (at “1”), followed by a series of harmonics with decreasing levels.

If we amplitude modulate a carrier with this ramp signal, we get the following time-varying signal; note again that this signal can be demodulated by an envelope detector:

The spectrum of the modulated ramp signal follows; note that there is a carrier at “0” and sidebands extending in both the positive and negative frequency directions. (In practice, this zero point would actually be at some high frequency, such as at 7 MHz for example. The spacing of the individual components in this example would be exactly that of the frequency of the fundamental component of the ramp signal.)

Recall from our earlier discussion that amplitude modulation results in a signal composed of the three components, the carrier signal, a lower sideband signal, and an upper sideband signal. Note the following as well: because the lower sideband component has a negative modulating-frequency term (cos(ω_c t - ω_m t), for a sine wave) the spectrum of the lower sideband is reversed compared with that of the upper sideband (and that of the baseband modulating signal).

We can also see from this example that amplitude modulation is rather wasteful of spectrum space, if our goal is to take up as little bandwidth as possible.  For one, the two sidebands are merely reflections of each other, i.e., each one carries the same information content.  For another, the carrier itself is unnecessary for the communication of the modulating signal as well — something that wastes power on the transmission side.

Taking that into account, we can choose to transmit only one sideband, resulting in a Single Sideband (SSB) Transmission. If we transmit only the lower sideband, its spectrum will look like this (note that the carrier is also absent):

SSB modulation can be implemented using a variety of methods, including an analog filter, or phase-shift network (PSN) quadrature modulation.  (For a clue as to how PSN works, look up and calculate the result of adding cos(x) cos(y) + sin(x) sin(y).)

The challenge in receiving this signal is how to demodulate it, as we can see from its time-domain plot:

As compared with amplitude modulation, a SSB signal cannot be demodulated with an envelope detector, because the envelope is no longer a faithful representation of the original signal.  One way to demodulate it is to frequency-shift the signal down to its original range of baseband frequencies, by using a product detector which mixes it with the output of a beat frequency oscillator (BFO).

One can appreciate that, if the demodulator BFO is not exactly at the original carrier frequency, the resulting demodulated signal will be frequency-shifted up or down by the amount of the error, resulting in a kind of “Donald Duck”-sounding voice signal.  While this was often an issue with analog transmitters and receivers, whose carrier frequencies were imprecise, and would drift over time, modern digital equipment is so accurate that a near-perfect re-synchronization is not difficult to achieve.

— agc

/ / /

Video Pioneers Remember Historic HDTV Debut

Grand Alliance Prototype

Twenty-five years ago this week, the world’s first HDTV broadcast system was unveiled in Las Vegas at the 1995 NAB Show.  AGC Systems’ Aldo Cugnini was there, as one of the many engineers who developed the “Grand Alliance” digital HDTV system.  Then at Philips, Aldo had a leadership role in the system’s development, which went on to become the ATSC digital television system.

Click here to see historic videos of the debut of HDTV.

Selected Papers

  • The Promise of Mobile DTV, NAB Broadcast Engineering Conference Proceedings, 2011.
  • A Revenue Model for Mobile DTV Service, NAB Broadcast Engineering Conference Proceedings, 2010.
  • Considerations for Digital Program Insertion of Multiple-Video Programs, NCTA Fall Technical Forum, 2002.
  • Digital Video and the National Information Infrastructure, Philips Journal of Research, Volume 50, Issues 1–2, 1996.
  • MPEG-2 video decoder for the digital HDTV Grand Alliance system, IEEE Transactions on Consumer Electronics, Vol. 41, Aug 1995.
  • Grand Alliance MPEG-2-based video decoder with parallel processing architecture, Intl. J. of Imaging Systems and Technology Vol. 5, No. 4, 1994.
  • The ISO/MPEG Audio Coding Standard, Widescreen Review, June/July, 1994.

NAB 2019 Conference Widely Featuring ATSC 3.0

More than 100 NAB Show sessions and more than 50 exhibitors will feature Next Gen TV technology that is now voluntarily spreading to cities throughout the country. Powered by the ATSC 3.0 next-generation broadcast standard, Next Gen TV promises to deliver sharper, more detailed pictures and lifelike multichannel audio with upgraded broadcasts that will be transmitted and received in the same Internet Protocol language as Internet-delivered content.

Jointly sponsored by the Advanced Television Systems Committee, the Consumer Technology Association and NAB, the “Ride the Road to ATSC 3.0” exhibit will be featuring a series of free presentations about all facets of the ATSC 3.0 standard. And attendees can pick up a free Guide to 3.0 at the Show in the Central Lobby of the Las Vegas Convention Center during the show.

Single Frequency Network Demonstrations

The NAB, with support from a number of technology companies, will demonstrate the Single Frequency Network (SFN) capabilities of the Next-Gen TV standard, showing how reception can be improved in difficult locations and in moving vehicles by deploying multiple broadcast towers transmitting the broadcast signal on the same channel.

Using several local transmissions, special SFN viewing kiosks will showcase the flexibility of the ATSC 3.0 standard. Dozens of sessions planned in the exhibit will include updates on the Dallas, Phoenix, Santa Barbara, East Lansing, Cleveland, and Korea ATSC 3.0 deployments.

Scores of papers and sessions will be presented about Next-Gen TV during the 2019 NAB Show, with session topics that will cover consumer research, consumer device plans, conformance testing, audio enhancements, station build-out advice, watermarking, advanced emergency information, channel security, advanced advertising and interactivity. In addition to ATSC, CTA and NAB, exhibit sponsors include Pearl TV, Sinclair Broadcast Group, LG Electronics, Dolby, Sony, Samsung and the AWARN Alliance. The centerpiece of the Ride the Road stage is a giant new LED videowall optimized for broadcast applications, provided by LG Business Solutions.

AGC Systems president Aldo Cugnini will be at the show, and available for discussions regarding support for ATSC and other related ventures. If you’d like to meet up, please contact us.

FCC Opens Up Spectrum Above 95 GHz

This month, the Federal Communications Commission allowed a plan to make the spectrum above 95 GHz more readily accessible for new innovative services and technologies. Calling the initiative “Spectrum Horizons Experimental Radio Licenses,” the plan is outlined in a First Report and Order, which allows a number of changes to existing rules, including:

  • a new category of experimental licenses, to increase opportunities for entities to develop new services and technologies from 95 GHz to 3 THz, with no limits on geography or technology; and
  • making 15.2 gigahertz of spectrum available for unlicensed use.

The Order specifically allows two types of operations:

  • A Spectrum Horizons experimental radio license can be issued for the purpose of testing and marketing devices on frequencies above 95 GHz, where there are no existing service rules.  Licenses are issued for a term of 10 years and may not be renewed.
  • Unlicensed operations are allowed in the bands 116-123 GHz, 174.8-182 GHz, 185-190 GHz, and 244-246 GHz, that are consistent with the rules proposed in the Spectrum Horizons, Notice of Proposed Rulemaking and Order.

Part 15 of the FCC Rules was also amended to extend operational limitations and interference measurements covering frequencies above 95 GHz.

The new rules provide that the Commission may, at any time without notice or hearing, modify or cancel a Spectrum Horizons License, if, in its discretion, the need for such action arises.  Some commenters raised the issue that this could result in an abuse of the complaint process, but the Commission pushed back, saying they “routinely work with parties to resolve potential or actual issues…”

The Commission withheld action on their proposal for licensed fixed point-to-point operations in a total of 102.2 gigahertz of spectrum, and opposed the concerns of the ham-radio organization ARRL regarding protection from interference.  In defending the latter position, the Commission states, “both the amateur radio service and the experimental licensing program are designed to contribute to the advancement of radio knowledge,” and goes on to say that “we will instead require all Spectrum Horizons License applicants to submit an interference analysis that would address the potential effects of the experimental operation on existing services.”  

In addition to Chairman Ajit Pai, the proposal has general support — albeit with certain cautions — from all four of the other commissioners, who evenly represent both sides of the political aisle. 

— agc

ATSC 3.0 Announcements at CES 2019

With the ATSC 3.0 standard essentially finished last year, the casual observer might have expected to see new product at this year’s CES Show in Las Vegas.

Indeed, while there were a few 3.0 TVs scattered about – including at invitation-only showings by well-known TV manufacturers at suites and hotels – they were only early prototypes, since we shouldn’t expect to see real product announcements until the 2020 show – which just happens to be when broadcasters have said they will crank up transmissions using the new standard.

Echoing this at the show was the VP of Communications at LG, John Taylor, who said, “We expect that the launch pad is really 2020,” which is consistent with the typical 18 to 24 month silicon design cycle for chips to follow a new standard.

ATSC 3.0 Software Stack

ATSC 3.0 is, of course, the latest version of the Advanced Television Systems Committee (ATSC) standard. It will support several advances including mobile viewing, 3D television, 4K Ultra High Definition (UHD), high dynamic range (HDR), high frame rate (HFR), and wide color gamut (WCG) picture quality, as well as immersive audio and interactivity.

Until we see those new products emerge, the news we’re more likely to see will be from broadcasters.


Industry Leaders Collaborate to Launch ATSC 3.0 Chip for Broadcast and Mobile Applications

ONE Media LLC, a subsidiary of Sinclair Broadcast Group, and India’s Saankhya Labs, together with VeriSilicon and Samsung Foundry, announced at CES the successful launch of an advanced multi-standard demodulator System-on-a-Chip (SoC) supporting the ATSC 3.0 standard.

The universal demodulator chip is based on Saankhya’s patented Software Defined Radio Platform, and supports 12 DTV standards including ATSC 3.0, DVB-T2, ISDB-T, and satellite and cable standards for TV, set-top boxes, and home gateways, as well for automotive and mobile applications.

This announcement follows Sinclair Broadcast Group’s recent commitment to a nationwide roll-out of ATSC 3.0 service and its past announcement to fund millions of chipset giveaways for wireless operators.

Two variants of the chip were announced: a “Demod-only” variant, SL3000, is designed for TV applications such as in HDTV sets, Set-top Boxes (STB) and home gateways. A “Demod-plus” Tuner variant, SL4000, is designed for mobile and portable devices, possibly making it the world’s first mobile-ready ATSC 3.0 chip. The mobile device is targeted to accelerate the adoption of the ATSC 3.0 standard across markets with both Direct-To-Mobile TV capabilities and Broadcast/Broadband convergence solutions.

The demodulator SoC was designed and developed by Saankhya Labs with ASIC turnkey design and manufacturing services from VeriSilicon, using Samsung Foundry’s state-of-the-art 28FDS (Fully Depleted SOI) process technology), chosen for its low-power capabilities.

Mark Aitken, President of ONE Media 3.0, said,

These mobile 3.0 chips validate the ‘sea change’ in over-the-air distribution of not only television, but all digital data. Broadcasters are doing their part by deploying the NextGen transmission facilities, and now there will be devices enabled to receive that data, personalized and in mobile form. This chip is the key to that disruptive future in a 5G world.”


Broadcasters and Mobile Operators Partner to Deploy ATSC 3.0 – Harman Separately Partnering in Mobile Applications

SK Telecom and Sinclair Broadcast Group announced in Las Vegas that the companies signed a joint venture agreement to lead next-generation broadcasting solutions market in the U.S. and globally. The two companies will jointly fund and manage a joint venture company within the first quarter of this year. The joint venture company will develop innovative broadcasting solutions based on ATSC 3.0.

The commercialization of broadcasting solutions based on ATSC 3.0 – which enables data communications in broadcasting bands – will give rise to new services such as personalized advertisement and in-vehicle terrestrial TV broadcasting and map updates. It will also support two-way communication between broadcasting companies and user’s smartphone/vehicle/TV by recognizing user’s personal IP address.

SK Telecom and Sinclair anticipate all television broadcasting stations throughout the U.S. will adopt broadcasting solutions based on ATSC 3.0 within the next decade. Through the joint venture company, the two companies plan to actively provide ATSC 3.0 standards-based solutions to all U.S. broadcasting companies and seek other opportunities globally. The joint venture agreement follows last year’s memorandum of understanding (MOU) signed between SK Telecom and Sinclair at CES 2018 to jointly develop leading technology for ATSC 3.0 broadcasting.

Separately, the two companies also announced at the 2019 CES Show that they signed a Memorandum of Understanding (MoU) with Harman International, a subsidiary of Samsung, to jointly develop and commercialize digital broadcasting network-based automotive electronics technology for global markets.

The companies intend to unveil their automotive platform and related equipment and services for the first time at the 2019 National Association of Broadcasters Show (NAB Show) in Las Vegas in April 2019.

— agc

ATSC 3.0 Featured Prominently at 2018 NAB Conference

“The Road to ATSC 3.0: Powered by ATSC 3.0” Ribbon Cutting CeremonyDeployment of ATSC 3.0 is off and running, with a strong showing this month at this year’s NAB Conference in Las Vegas. More than 40 exhibitors and 22 technology-and-business sessions demonstrated the level of interest in the new Next Generation Broadcast TV standard, with a ribbon-cutting ceremony kicking off the activities.

ATSC President Mark Richer underscored the level of 3.0 presence at the show, saying “That’s how we know it’s real, and that’s how we know it’s happening,” and Sam Metheny, EVP/CTO at NAB, said that while ATSC is now “moving to the implementation phase,” it is a “living standard that will continue to evolve over time.” Mike Bergman, ‎Senior Director, Technology & Standards at the Consumer Technology Association, anticipates “broad deployment, and a breathtakingly immersive viewing experience,” which should complement the growing momentum of 4K TV sales.

Now that the ATSC 3.0 standard has been approved, broadcasters can develop two-way, IP-based connections with their viewers and deliver TV experiences on par with other digital media. Looking to the future, conference panelists addressed key Next Gen TV capabilities, including enhanced audience insights, addressable advertising, interactivity, and personalization, along with plans to generate incremental revenue and audience engagement.

Broadcasters are used to slow change, but now need to change faster, even on a monthly basis. The world is changing faster, and consumer demands are changing, with OTA viewership growing, and OTT services and usage growing. Mobile viewing continues to increase, a cord cutting / shaving / nevers are changing TV marketplace dynamics. On-demand viewing is an assumed feature, and digital advertising is increasingly powerful, so targeted advertising is now essential.

Chart courtesy of NAB Pilot Program

SFNs (single-frequency networks, a broadcast technology comparable to mobile cellular networks) will enable all of these new services, and data analytics will drive the opportunities. The WiFi/mobile broadband return channel defined by ATSC 3.0 means that even simple receivers need a back channel.

While MVPDs (Multichannel video programming distributors, i.e. cable and satellite) have long provided a revenue stream to broadcasters through retransmission-consent agreements, this could be one key area of the change in business model made possible by ATSC 3.0, which is not mandated by the FCC, other than at the transmission layer, and whose carriage is not currently subject to retrans obligations.

Broadcasters are interested in gathering viewership data from mobile devices and doing dynamic ad insertion. Reaching individuals will be attractive to advertisers, and broadcasters can now put movies into home boxes for Netflix, bypassing MVPDs. ATSC 3.0 is thus poised as a medium to test new business models, and broadcasters can partner with other spectrum owners and mobile carriers to supplement the “traditional” mobile spectrum.

The Phoenix Model Market project is the first collaborative single-market effort to plan for and implement a transition to next-generation over-the-air television broadcasting. Twelve stations in the Phoenix market are participating, with service testing expected to start Q2’18, and consumer service testing in Q4’18. In addition to business model testing, consumer testing will extend into 2019.

Among the consumer-facing business models to be tested are program guide & hybrid TV, personalization, and emergency alerts. On the broadcaster side, content protection, data & measurement, advanced advertising, and transition models will be evaluated.

— agc

Next Generation Broadcast TV

AGC Systems has advised and worked with clients to influence, develop, and realize the technologies that form the basis of Next Generation Broadcast Television (NGBT), including the ATSC 3.0 Broadcast Standards.  Starting with the original ATSC Planning Teams, and progressing to the latest developments, we have participated closely in the development of:

As a result of our advisory services, our clients have achieved their short- and long-term objectives for new business development.