Monday, July 28, 2014

iBiquity Vs. Patent Trolls

The legal complaint is as dry as most any other. It is rife with what is pursuant to whom, proper venues, infringements, hereins and obligations to indemnify. But it gets exciting for one single solitary sentence.  "Had the patent examiner known or been made aware of these prior art references, the claims would not have been allowed and the [5506866]patent would not have issued." Aside from the vicarious joy of punting a patent troll around the DC beltway, how is this legal spat important?

Ok so it still sounds dry but what iBiquity  is saying as politely as they can is that the patent examiner is an ignorant clod. Instead of arguing just that Wyncomm are malevolent twats, iBiquity is essentially arguing that our patent system is broken and stupid. While both of these things are true, I think it's the second assertion which has legs. Technology patents are arcane, complex, and nearly impossible for a layperson to understand. I'm not saying the patent examiner is lazy, or dim, or didn't make a sincere effort. The problem is that compared to a radio engineer, mathematician, or C++ programmer a lay patent examiner doesn't have the proverbial snowballs chance in hell of understanding all the technical nuances of a complex patent.
More here So let us examine the material in question: U.S. Patent Numbers 5506866, 5642379 and 5475691.

5506866 - Filing Date 11- 15-1993
It originally belonged to AT&T but was used as loan collateral and was held by both Patent Business Development LLC and Clearwater Innovations LLC in recent years. The patent covers a narrow use of side-channel communication which can carry simultaneous voice and data transmission. Here they argue that they invented a technique to simultaneously transmit voice and data while also transmitting additional information separate and apart from the voice and data information. In webcasting we might call that third stream metadata. In broadcast radio we might call it RDS. They are describing transmitting data while broadcasting in CDMA. Ridiculous. Telegraph signal multiplexing dates to at least the 1870s, telephone multiplexing to at least the work of George Owen Squier in 1910. Prior art is an understatement. At the same time confusing this for IBOC (NRSC-5) is patently ridiculous.

5642379- Filing Date 06-14-1993
This patent describes a technique for modulating orthogonal signals with one or more analog or digital signals. Don't be intimidated by the word orthogonal. Even stereo LPs exhibit orthogonal signal. It just means having two overlapping but uncorrelated signals. Both TDMA and OFDM can be described as orthagonal. Any simultaneous transmission of two signals could be considered prior art. In this patent they describe voice and data, but it lists a large number of virtually identical patents: 4280020, 4313197, 3824347, 3875339 and others. This tries to solve the non-existent problem of FFT bandwidth. It does so with a common bandpass filter. Please just stop.


5475691 - Filing Date 11- 15-1993
Voice activated date rate change in simultaneous voice and data transmission. This technique is said to improve the transmission quality of the voice signal by dynamically adjusting bits per symbol. This is already used in everything from Ethernet LAN to HDTV.  Trying to increase this number is essentially the history of all IT hardware between your modem and your ISP.  This one is beneath our contempt.

Friday, July 25, 2014

DE SVO

This is a peculiar CW, and if you look on Youtube you'll find another dozen recordings of the same broadcast, all of varying fidelity.



That is the sound of a maritime coastal station SVO in Pirgos, Greece. They broadcast on 8424 KHz providing VHF and high frequency radio telephone and high frequency simplex teletype over radio (SITOR) services to seagoing vessels. I'll post about SITOR some other time. More here.That message is "DE SVO" then a long beep.  DE is a shortwave abbreviation for "this is" making the message: "This is SVO."  


Thursday, July 24, 2014

Six Years of WCMA

Not every radio station makes the cut. Most often the license is sold and the station changes form and format. But sometimes, like a shoe-string produce stand in the bad part of town... it just quietly goes away one night. This is less common now, excepting unprofitable Small-market AMs. But back in the 1930s the FRC frequency re-shuffling of the AM band bore many casualties. Take for example the short life of 1160 WCMA-AM. More here.

The station signed on in march of 1925. The 1926 Radio Service Bulletin indicates the original calls were 1350 WHBH but this changed to WCMA a year later.  Built by major George Eisenhard at Culver Academy. He had built a 75 foot antenna tower and had been demonstrating radio at least as early as 1910. It's 150 long wire was erected atop the campus Rec building and it's second floor balcony served as a makeshift studio. In the early 1930s it moved to the Johnson apartments on Lake Shore Drive. A 1926 issue of the South Bend News-Times marked the official debut of WCMA:
"WCMA is the new Culver Military Academy broadcasting station, which was formally opened and gave its first program on the evening of Nov. 29. So many artists have been engaged, and the public seemed so clamorous for encores, through telephone and telegraph messages received, that the program extended from 8:30 o'clock that evening until 2 o'clock the next morning. Thousands of fans listened to the program that evening, and hundreds of congratulatory messages received at the station on the following day. It is the best broadcasting station in northern Indiana, and sends on a wavelength of 258.5 meters."
In the 1930s it was sold to the General Broadcasting Company. As a day share it broadcast every afternoon from 1:15 PM to 5:00PM, a mere 4 hour slot. It's SM was Carl B. Watson. The aired a mix of news, commentary and musical programs. A local newspaper, "The Culver Citizen" produced a regular program on local news.  But despite the promising start, things went awry. The News-Sentinel covered the story of it's closing in November of 1932. More here.
"Culver, Ind. - WCMA, Culver’s radio station, was discontinued this week after operating for six years. The station has been sold along with Station WKBF at Indianapolis, to a Chicago firm which will combine the time at the two stations. The Culver station was established by Culver Military Academy and maintained by it for four years. It was then sold to the Curtis company of Indianapolis, which moved the equipment from the academy to the Johnson apartment building in the north part of Culver. Louis Lohr has been manager and engineer of the station."
The radio station equipment was donated to their state radio police system. The towers atop the rec building at Culver acedemy weren't taken down until 1947, several years after the passing of Maj. Eisenhard. Today the call letters live on at 1600 AM in Bayamon Puerto Rico. 

Wednesday, July 23, 2014

SCM SCR SCS

Just when you think you have all your jargon and technical terms down someone whips out an acronym you don't recognize.  The acronym SCM stands for Set, Complete, Meteorological. It's one of three related WWI Radio Signal Corps acronyms. More here.

  • SCM - Set, Complete, Meteorological
  • SCR - Set, Complete, Radio
  • SCS - Set, Complete, System
 The book World War II Battlefield Communications by Gordon L. Rottman covers this in some further detail. U.S. military radio equipment has been designated S.C. since 1909 standing for Set Complete.This may have distinguished it from radio parts in that era. This was a prefix to every model number. For example an SCR-300 was a portable radio transceiver radio used in WWII. The SCM-1 was a Mobile Meteorological Station used in the same conflict.In that context by the way mobile means vehicle mounted. More here.

There was also a huge number of two-letter designators for the components and accessories for all these units. Some were pretty obvious, AT indicated antennas, HS for headsets, LS for loudspeakers, GN indicated generators, BA indicated batteries. BC was less obvious,  basic components like a receiver. But RD stood for switchboards and EE for telephones, 

In 1943 still in the middle of WWI the military introduced an all new numbering schema. This was called the "Joint Electronics Type Designation System" aka the “Army-Navy System” or “AN System.” (It was not actually used by the navy.)  It was later changed to JETDAS with the inexplicable addition of the word "automated."  But thankfully they did not re-designate existing models. As time passed the new system was applied to new devices and as technology progressed those older units fell out of service.

Tuesday, July 22, 2014

Transcription Mystery Disc #223


This is a 6.5-Inch paper-core Wilcox-Gay Recordio brand acetate. It is in decent shape and relatively flat but has some marring from having been stored in a stack. It bears some light pencil markings "Dolores + eb + Les for Bev"  The other side reads "For Bev - By Dolores."  INcreasingly I have issues with paper core acetates. If you store them flat the surface mars from downward pressure. If you store them vertically they warp. There is no right answer. In this case the surface noise varies. I've adjusted the noise filter as much as I could but it's far from perfect.

 Shortnin' Bread



This recording is of two children's songs, the first is "Shortnin' Bread"  and the second is unintelligible. The tune Shortnin' Bread dates back to at least 1900, and probably longer.  It was documented across the south by 1925 attributing to that fact. This version was probably recorded in the late 1940s based on the make of the disc.