Students of history know that France and the UK have rarely agreed on anything. However, a recent visit to the 2 countries confirmed that jamming cell phones in prisons is one thing they actually do agree on, although they reached this consensus independently.
The above French text is from a 2002 law approved by the French Parliament and signed by President Chirac. It permits jamming in both within the walls of prisons (l'enceinte des établissements pénitentiaires) and also in performance halls (les salles de spectacles) such as concert halls and theaters. (Note that no responsible parties in the US advocate permitting cell phone jamming in anything comparable to les salles de spectacles.)
While there is no comparable law or regulation in the UK, a well placed industry source confirmed that Ofcom, the UK regulator, recently helped a number of UK government departments and mobile operators reach agreement on this, resulting in a confidential MoU between them paves the way for jammers in prisons.
Now it is puzzling why UK and French cellular operators are willing to help their governments solve the real public safety crisis of cell phones in prisons while the US cellular operators cling to their interpretation of 47 USC 333 that FCC does not have jurisdiction to do so. At the recent FCC public forum on the issue, all speakers from other than the cellular industry advocated allowing both jamming and “managed access”.
Question for those who advocate the above reading of Section 333: Section 333 mentions neither FCC nor NTIA (or the President who has delegated his Section 305 authority to NTIA). Why is it obvious that NTIA can authorize jamming and FCC can’t? The legislative history of this section is very different than this interpretation of restricting FCC jurisdiction.
Note that Section 303 explicitly exempts NTIA from its terms. If Congress meant that Section 333 didn’t apply to NTIA, why didn’t it say so?
§ 333. Willful or malicious interference
No person shall willfully or maliciously interfere with or cause interference to any radio communications of any station licensed or authorized by or under this chapter or operated by the United States Government.
John retired in January 2010, after over 40 years of public service. He developed the AM skywave propagation model, which is now in Part 73 of the FCC Rules, and contributed significantly to ITU-R Rec. P.1147.
John Wang received his BSEE degree from the University of Maryland in 1959, and his MSEE degree from the University of Pittsburgh in 1968. He taught at Penn State before joining the technical staff of the FCC in 1969. His research interests include ionospheric propagation and has published more than 40 technical papers in different professional journals. His most important contributions to the telecommunications community include the development of a LF/MF sky-wave propagation model which forms an important part of the FCC Rules. His propagation model is now recommended by the International Telecommunications Union (ITU) for world-wide applications (Recommendation P.1147). He is a Fellow of the Institute of Electrical and Electronics Engineers (IEEE) - an honor given only to 2 other FCC engineers in recent memory.
John has been active in the Radiocommunication Sector of the International Telecommunication Union (ITU-R) since 1978. He also represented the USA to the 1980 and 1986 Radio Conferences together with several AFCCE members, and chaired the propagation groups. Although retired from the FCC, he currently still serves as the vice chairman of ITU-R Study Group 3 and the chairman of its working party on ionospheric propagation.
His avocations include astronomy, bridge and Chinese history. He has written several papers on the sightings of sunspots in ancient China and the Star of Bethlehem.
Here are John’s remarks at the award ceremony
Mr. President; Ladies and Gentleman; My former colleagues at the FCC: It is a greathonor to receive this most prestigious award. It is a great pleasure to see so manyfriends here tonight.
I was very fortunate because when I came to work for the FCC in 1969, there wasalready a very large databank in existence waiting for me to study. FCC skywavework started during WW II. Hundreds of engineers and technicians had alreadycontributed to it in the last sixty years. Tonight, standing here alone to receivethis honor, I feel somewhat guilty.
I am not going to touch the mathematics. That is left to Ron Chase and Bob Weller. I will only point out some future applications I was not able to pursue. As you areaware, the new skywave model differs from the old clear-channel curve in one majorarea. The new method contains a latitude term. Latitude is a very important factorin propagation. As a rule of thumb, skywave signal level increases by about 1 dBwhen latitude decreases by 1 degree. In other words, the old clear-channel curve,which is still the official method for ITU Region 2, over predicts field strengthsin the high-latitude areas and under predicts in the low-latitude areas.
If the new method is used between US and Canada, some existing stations may beallowed to increase power. Some stations may be allowed to extend operating hours. And there will be more stations allowed on the air. It would be a WIN-WIN situationfor both countries.
The situation in the southern hemisphere is more complicated. In US, the upper limitof power is 50 kW. In Latin America, the sky is the limit. There are many stationsoperating with 500 kW or more. In other words, their arms are longer. They cancause interference to us but not vise versa. On top of this, the skywave modelbeing used has a tendency to under predict interference levels in this part of theworld. US stations are thus in a highly disadvantageous position. By switching tothe new method, sources of interference will be more accurately identified.
The first regional broadcasting conference governing North America (or, NARBA) tookplace in 1950. Thirty years later, in 1980, another regional conference took place.It is time for the ITU to convene another round of broadcasting conferences. I amconfident when that time comes; you young engineers will be able to accomplish whatI have not been able to do. Thank you.
Congratulations, John, on this well deserved honor.
The Unfinished Radio Revolution:
New Approaches to Handling Wireless Interference
cosponsored by Silicon-Flatirons, IEEE-USA, CTIA, New America Foundation, and FCBA.
Innovative wireless communications is important not just for wireless operators and manufacturers, but also for firms in other industries that depend on the latest technology for improving their productivity and for new non-telecom firms such as Amazon, E-bay, Netflix that are enabled by cutting edge technology. It is key to the health of the US economy.
Most other industrialized nations use a state capitalism form of spectrum management and wireless industrial policy that uses Soviet-style economic planning
In contrast, since late 1970s FCC spectrum policy has focused on technical deregulation and market forces to stimulate innovation and growth. This year is the 25th anniversary of both Qualcomm’s founding and the regulatory basis for Wi-Fi and Bluetooth – all products of this deregulatory ferment.
Spectrum deregulation has a core goal of interference prevention:
- Assuring incumbents of realistic expectations so as to stimulate their investment AND
- Assuring innovators and entrepreneurs a transparent and timely red light/green light system for determining if innovative systems will cause “harmful interference”
FCC got it right in the Wireless Innovation NOI when it said
The viability of spectrum access for new radio services often centers on whether the new service may cause harmful interference to incumbent services. This can lead to delays through protracted rule making proceedings that can create uncertainty and discourage investment.
In the Northpoint/MVDDS, UWB, and AWS-3 proceedings we saw deliberations of harmful interference that not only violated the timeliness requirement of Section 7 of the Act but were totally inconsistent with any plausible business plan of a startup entrepreneur. Today’s capital markets make investments for such innovative technology almost impossible due to the excessive regulatory risk resulting from FCC’s slow deliberations.
Qualcomm got its key regulatory decision for CDMA 2 years after its founding. Such decisiveness in innovative spectrum policy is impossible today
Spectrum policy determination by fiscal exsanguination of entrepreneurs is both ineffective and inconsistent with our form of government.
If we can’t get spectrum deregulation and interference policy correct, the USA might be better off just joining CEPT and taking an active role in their spectrum management system - based on Soviet style economic planning.
Basic technical Issues in defining radio rights or interference
Explicitly stated expectations for adjacent channel rejection and intermodulation vulnerability, e.g. 3rd order intercept point, are urgently needed for each radio service in order to resolve harmful interference issues in a timely way. These standards should not be mandatory - which is just as well since FCC in general does not have such jurisdiction at present.
I/S Protection at Receiver
Made simpler by digital convergence. In most cases I/S of - 6 to -10 db is adequate, former mixed analog environment was more complex. However, CDMA systems have more complex concerns since interference translates into capacity. But environment noise levels set a natural baseline
I/S Field Strength at the Antenna vice I/S Power at the Receiver
MIMO technology is increasingly practical so in many cases some rejection by antennas should be considered
Much of the controversy over TV white space results from the use of a 1966 precomputer age propagation model that FCC itself has said has severe limitations in its applicability. While propagation is an esoteric field, inappropriate models can warp any spectrum rights regime
MCL vice Stochastic Modeling
Incumbents prefer that the worst case MCL (minimum coupling loss) scenario is decisional. While FCC has a limited record of using stochastic modeling , both FCC and NTIA have no clear policy in this key area. However, in Europe, stochastic modeling is often used
Acceptable Interference Statistics
How much interference is acceptable? In the MVDDS decision FCC used naturally occurring rain outages as a baseline and decided to accept a 10% theoretical increase – something not noticeable in practice. FCC and NTIA should consider the general issue that naturally occurring outages in space and time should be considered as a reference point although the allowed increased should be determined on a case by case basis
Who should make detailed spectrum rights proposal for public consideration?
It is key that FCC and NTIA work in parallel here to develop consistent policies
Doubtful that present FCC or NTIA can develop a level playing field interference protection scheme that deals with both incumbents and new entrants fairly
In the 1970s, FCC - like other federal regulatory agencies with key long term technical policy dilemmas - asked National Academy of Sciences/National Research Council to propose regulatory framework for what later became Parts 25 and 68 – at the time exceedingly controversial issues opposed by powerful interests. The resulting C band terrestrial/satellite sharing and telephone interconnection resulted in tremendous economic growth and were emulated all over the world.
FCC and NTIA should consider asking NAS/NRC to repeat its past role – and the role it regularly plays for other agencies – to draft a specific framework for determining interference rights that balances all interests. It will never be an objective definition, but a framework that speeds up the present process will increase certainty for BOTH incumbents and innovators.
Your blogger’s detailed paper on this topic
There is life after FCC! My friend and former FCC/IB staffer Emily Murase has been campaigning for one of three positions on the San Francisco School Board. (Remember San Francisco? That’s the place that is so hostile to the cellular industry that they will never have a convention there again.)
Emily survived a primary fight to make it to the general election. On election night she was in 4th place and apparently out of the running. But as absentee ballots were counted she is now up to 2nd place and a likely seat on the board. But a lot can happen in absentee counting. Emily writes in her blog:
I now have 64,741 votes, but there are still over 20,000 ballots left to count, so anything can still happen. The Elections Department expects to count the final batch of ballots, provisional ballots, beginning on Monday, so final results may not be known until mid next week. Don't be surprised if I slip back down to 3rd place. I just need to hang on to 3rd to win 1 of the 3 positions on the San Francisco Board of Education in this year's election.
So the Alaska Senate race is not the only one where counting is slow in this computer age!
So congratulations to Emily for her fine showing and best wishes that her standing in the race holds up.
We will update here as more news becomes available.
Final results are in - Emily won!!
This blog alone announced the winners in 2007. Clearly the Commission does not intend these awards to be secret since the 2009 awards were announced at the 8/27/09 open Commission meeting although there was no written announcement. We hope that the Commission develops a more transparent process for announcing awards for staff excellence so that in the future so we will lose these annual items. We hope that outstanding FCC staffers get broader recognition than in this blog - even though we know the policy elite reads this blog.
Indeed, the only trace on the Commission website that these awards exist are the remarks of Comm. Tate at the 2007 ceremony that was not otherwise announced. Let me reprint here part of her gracious remarks:
The projects on which our engineers, scientists, and technical staff work cover – to mix metaphors a little – the full spectrum. They help ensure radio transmissions do not exceed safe levels. They help represent the interests of the United States in international negotiations.
This award recognizes engineers, scientists and other technical staff for outstanding contributions performed in the course of their work at the Commission.The engineers, scientists, and technical staff are truly the Commission’s unsung heroes. While the attorneys tell us how to follow the law, and the economists tell us what will or will not be efficient, our technical experts tell us ultimately what can and cannot be done. Without them, very little would be done.
To all recipients of the ... Excellence in Engineering Award, you have my deep respect and gratitude. The American people may be less aware of the good work you do, but they are no less indebted to you. Thank you.
But from a source deep within FCC, here are the winners of this year’s award. I have been unable to find the citations behind the awards and will add them if I get them:
- Reuben Jusino (Enforcement Bureau)
- Joseph Husnay (Enforcement Bureau)
- Group Award: Jon Sprague, Greg Coons, Jay Hokanson (Enforcement Bureau)
- Group Award: Behzad Ghaffari, Tom Peters, Pasquale Amodio, Ziad Sleem, Walter Johnston, Kurian Jacob, Yoon Chang, Jerome Stanshine (PSHSB, WTB, OET))
An article by columnist Mark Scherer entitled “Cell-Phone Safety: What the FCC Didn't Test” is in this week’s Time magazine. It points out
FCC testing regulations notably chose not to simulate a situation in which the phone was broadcasting at full power while inside a shirt or pants pocket flush against the body, an odd oversight given the known habits of many cellular-phone users. As a matter of physics, radio-frequency energy generally increases sharply as distance is reduced. "The exposure is definitely related to distance," says (retired FCC RF safety expert Robert) Cleveland.
OET Bulletin 65, Supplement C (“OETB65C”) shown at left. This publication is not codified in the FCC rules and was last revised in January 2001, almost a decade ago. Whether or not the content of this publication made sense when it was adopted in 2001, a lot has changed since then in the use of the covered devices and new devices like my beloved iPod Touch, essentially a PDA with Wi-Fi, have become common.
The provisions Mr. Scherer was writing about are on p. 41-2 of OETB65C. They say:
Body-worn operating configurations should be tested with the belt-clips and holsters attached to the device and positioned against a flat phantom in normal use configurations. ... Both the physical spacing to the body of the user as dictated by the accessory and the materials used in an accessory affect the SAR produced by the transmitting device. ...Body-worn accessories may not always be supplied or available as options for some devices that are intended to be authorized for body-worn use. A separation distance of 1.5 cm between the back of the device and a flat phantom is recommended for testing body-worn SAR compliance under such circumstances. Other separation distances may be used, but they should not exceed 2.5 cm.
An phantom used for SAR measurements.
Simulated cavity is filled with special liquid
to simulate body’s electromagnetic qualities.
Cell phone tested is under body cavity.
The above quote from OETB65C essentially allows the device manufacturer to assume a distance from the body of 1.5-2.5 cm (0.59-0.98 inches) even if they do not provide any holder that keeps it that far from the body. Mr. Scherer describes this as “an odd oversight given the known habits of many cellular-phone users.” Someone who was involved in the writing of this document told me that it was not an “oversight”, but rather strong industry pressure on senior OET leadership at the time that resulted in the “apparent oversight”. Since this document was not written in a rulemaking, there is no paper trail and no transparency. Why determine the SAR limit in a rulemaking if you can nullify much of it in a document such as OETB65C?
Indeed, don’t a lot of people carry cell phones, Blackberries, and iPhones in their pockets? In view of the FCC’s recent interest to help inform the public about SAR by writing a whole consumer fact sheet entitled “SAR For Cell Phones: What It Means For You”, isn’t it odd that the need to maintain the same spacing as used in SAR testing is essential is never mentioned therein?
So suggestions for FCC to think about in this area:
- Maybe OETB65C, and the other parts of the OETB65 series, should be revised at least once a decade?
- Maybe the FCC/CGB fact sheet recently issued to explain SAR should also point out that the SAR measured to be in compliance with FCC rules is not meaningful unless the consumer actually uses the phone with the body separation that was assumed.
- As previously stated in this blog, maybe the FCC/CGB fact sheet should also point out that Blackberries/iPhones used in the “typing” mode are subject to a higher SAR limit of 4.0 W/kg so that there is a significant safety margin when they are used in this mode. SAR measurements in this mode are not normally made available to the public in a convenient form.
- FCC/CGB and CTIA might want to think about making more pragmatic information available about decreasing exposure from cell phones - it isn’t proven harmful, but it certainly isn’t doing you any good. The graphic below is from a web site operated not by a radical environmental group, but from AFOM - the French counterpart of CTIA. In this case it points out simply and clearly that cell phones operate at maximum power, hence maximum SAR, in areas with weak signals and that health authorities suggest using your phone in strong signal areas preferentially. Of course, carriers with poor signal coverage - and hence higher operating SARs in their customer’s phones - might prefer that the public not know this. However, a Bluetooth headset will reduce SAR even in this case.
I can not recall a previous meeting solely focusing on spectrum. Some cynics argue that the Chairman’s Internet agenda is going nowhere so he is now focusing on spectrum as an area to leave his mark.
Here are the items scheduled for the meeting:
• TV Spectrum Innovation NPRM: A Notice of Proposed Rulemaking seeking comment on rules to facilitate the most efficient use of the UHF and VHF TV bands. These proposals, an important step toward the agency’s spectrum goals as outlined in the National Broadband Plan, would remove a host of obstacles to mobile broadband use within spectrum currently reserved for use by TV broadcasters, including through innovations such as channel sharing and generating increased value within the VHF band.
• Experimental Licensing NPRM: A Notice of Proposed Rulemaking seeking comment on proposed rules to facilitate greater experimentation in the wireless space. The NPRM suggests making the Commission’s experimental licensing rules more flexible, including by easing testing restrictions on universities, research organizations, and other institutions that are developing new wireless services and devices. The goal is that the resulting testbeds would encourage innovation and help speed the time to market for new technologies.
• Opportunistic Use NOI: A Notice of Inquiry seeking comment on ways to accelerate “opportunistic use” of underdeveloped spectrum in both licensed and unlicensed bands, including how technological innovations can effectively foster secondary markets.
The plot at left from Qualcomm’s briefing shows that with today’s analog wireless microphone technology, wideband FM dating back to Maj. Armstrong in the 1930s, capacity increases slowly with available spectrum. While this technology uses bandwidths of 100 kHz or more, the real limit in places requiring a high density of wireless mics - such as a theater stage - is intermodulation which generally results from receivers or antenna amplifiers that are not sufficiently linear.
Intermod in theaters can also result from wireless mic transmitters that are near each other (such as redundant mics on key players and actors who are standing next to or embracing each other) and interact with each other due to the lack of adequate RF isolation in their designs. While intermod could be corrected by improving analog FM equipment, today’s digital technology offers options that are intrinsically immune to intermod. The new Qualcomm chipset uses the same basic OFDMA technology used in WiMAX and LTE.
With the kind permission of PolicyTracker, here is their recent news report:
(Note that in UK-speak PMSE = program(me) making and special events = wireless mics)
Qualcomm announces chipset for digital wireless mic
©PolicyTracker Oct 27, 2010
by Martin Sims
Qualcomm says it has developed a chipset for an advanced digital wireless microphone with much greater spectrum efficiency than current analogue models. However, industry experts are sceptical about its likely power consumption.
While digital switchover will bring digital TV to everyone and more spectrum for mobile operators, wireless microphone users and the PMSE (programme-making and special events) community could lose out. In recent years, 790-862 MHz has been an “unofficial harmonised band”, according to Wolfgang Biltz of the Association of Professional Wireless Production Technology. “Travel all over Europe and you could always find a frequency which works for you – legally,” he said. However, 790-862 MHz will soon become the European mobile sub-band, meaning that many PMSE users will be looking for a new home.
The European Commission thinks that solving the problem requires action at the EU level and its recent digital dividend Communication called for the identification of harmonised bands. To help find these bands and to discuss other possible solutions, like the use of cognitive radio for PMSE and the transition to digital technologies for wireless microphones, the Commission held a worksop in Brussels on Tuesday 26 October.
Digital era closer than expected?
A move to digital could be one solution for wireless mics because increased spectral efficiency would mean that users could be accommodated in a smaller number of bands. So far the industry view has been that analogue mics will continue to dominate for many years to come. “We will see analogue transmissions for the next 10-15 years: it's efficient and higher quality and that is key to us,” Volker Schmitt of Sennheiser told the workshop.
This ought not to influence policy until it is embedded in a mic and being sold in a box
What surprised participants was Qualcomm's revelation that it had developed a chipset for a digital wireless microphone. Cyril Measson, a senior engineer at the company, said they were keen to partner with manufacturers and could make the chipset available to them in six months. “We are not talking about the future, we are talking about now,” he said.
Qualcomm's technology, which is intended for the professional wireless microphone market, is based on synchronous OFDMA and operates within existing 200 Khz channels. It uses the 2.4 GHz band and offers a range of up to one kilometre. Sound quality is 24 bit / 48 khz and it can pack 30 mics into 6 MHz.
Significantly, Measson said Qualcomm’s digital system could achieve the same latency as analogue systems: a delay of only three milliseconds at 100-200 metres. Latency, or the time it takes for the sound to be electronically processed and amplified, is crucial for PMSE users like musicians as playing or singling along is impossible if there is a significant delay in hearing the sound coming back.
Measson also said that the digital technology would enable the performer to transmit data back, allowing new ways of using wireless microphones. Qualcomm calls this its Interactive Venue Media System.
The power problem
Volker Schmitt of Sennheiser accepted that digital was the future and called Qualcomm's system “pretty amazing” but said there were great concerns about battery usage. “We have had a look at digital, we have looked at OFDM but it is not here yet because of power consumption,” he said. Schmitt said the problem came because of the need to use a special type of signal amplifier in order to achieve high audio quality with low latency. These linear RF amplifiers have very high power consumption, meaning that battery life would be too short and the battery packs would be too large for performers to wear. However, Measson said Qualcomm’s was a state of the art technology with an advanced power control system.
Digital mics may arrive more quickly than many people think
Like Schmitt, many attendees remained concerned about the battery life issue. “This is vapour-ware,” said one participant. “It ought not to influence policy until it is embedded in a mic and being sold in a box.”
Schmitt's view of the digital timescale was very different to Measson's. “Digital will come, but it's not around the corner,” he said. “We need three to five years for research, followed by extensive field tests...then two to three years for product development.”
Professor Georg Fischer, co-chairman of the ETSI group on cognitive PMSE systems, told participants that a move to digital alone would not resolve the issues facing the industry. He told the seminar that PMSE was not spectrally inefficient per se, considering the audio quality required, and he saw great possibilities in using the cognitive approach to analogue wireless mics.
It is also worth noting that manufacturers' pessimism about the development of digital wireless mics is not universally shared. “Digital mics are available, I have heard them in performances and they were perfectly acceptable,” one workshop participant said. “They may arrive more quickly than many people think.”
Note the key parameters in the above: 24 bit digitization (CD quality sound), 48 kHz sampling (resulting in 20+ kHz of audio, again CD quality), and < 5 ms latency/delay (important in live theater). There is some question about power consumption/battery life but it is hard to see that that is a key issue as actors do not stay on stage for hours at a time. I was amused by the quote: “ ‘This is vapour-ware,’ said one participant. ‘It ought not to influence policy until it is embedded in a mic and being sold in a box.’ “ How many times have I heard this thought? Regulators should wait under R&D people use private capital to develop products that have no market without regulatory action and not make any decisions until the technology is fully proven. Where would computer technology be if the Federal Computer Commission has to actively approve every new PC model’s technology under ill defined criteria in front of a crowd of competitors before it could be sold?
Compare the efficiency given by Qualcomm, “30 mics in 6 MHz” with the statement in the FCC’s newly adopted 15.713(h)(9) “As a benchmark, at least 6 – 8 wireless microphones should be operating in each channel used at such venues (both licensed and unlicensed wireless microphones used at the event may be counted to comply with this benchmark).” The Qualcomm technology could achieve 4-5 times what FCC recently viewed as a benchmark.
This new Qualcomm announcement may obsolete the recent decision before it is even published in the Federal Register!