Month: September 2015

Telephony in Radio Broadcasts, part three

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Jason, the guest writer on Avaya’s SIP agenda, has kindly given me some stuff to post while I’m out of the office at the Museum of Telephony. This is the last installment of this series.

Some technologies I never used:

 Other larger stations would use ISDN directly to the hybrid.  It’s my understanding that this is like presenting a PRI directly to the hybrid with no front PBX. It was stable, and the audio quality was as good as the CO’s switch.  In these cases, the caller’s analog or cellular connection was often the limiting factor for audio quality.  I would imagine these are the type of systems used by the big talk show hosts like Glenn Beck or Rush Limbaugh.

 Remote broadcasts in other markets are moving to a full internet based VoIP solution, where the remote broadcasters has a unit that speaks IP to the nearest internet connection and negotiates a VoIP “call” to the dedicated hybrid at the studio. I’ve even seen apps for smart phones that allow this style of connectivity using the phone’s hardware to do the VoIP work and the cellular data network for the data. I’m not sure I’d want to try this in a mission critical application!  On the other hand, it’d certainly sound better than a raw cellular call and doesn’t have the hassle of setting up a microwave link.

 In the studio, if SIP is king, Hybrids are available to consume SIP audio just like an IP phone.  I would imagine if you have good SIP trunks these sound delightful!

 There you have it.  Telephony meets Radio.  I think so long as radio is around, you’ll continue to have talk show callers, contest callers, callers who want to know the weather.  Despite the push to the Internet, telephony is still the preferred method for many radio listeners to communicate and have a voice in their station, no pun intended!

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Telephony in Radio Broadcast, part two

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Jason, the guest writer on Avaya’s SIP agenda, has kindly given me some stuff to post while I’m out of the office at the Museum of Telephony.

A Better Way

 The other company I worked for was a five station cluster.   There were 5 on-air studios and 3 production studios. Unlike the other station, it was possible to record production in either an on-air studio or a production studio.  The main PBX was a Toshiba Strata which served the office staff, but not the on-air callers. (News Talk excepted, see below).

 The philosophy at this company was that each station would have a hotline which consisted of one or more lines in hunting independent of the PBX.  The busier stations were equipped with a Telos One-x-Six which provided line appearances for up to six lines.  It had a single hybrid, which could choose any of the six lines at will. The one disadvantage of this system is that in most studios there was no way to screen callers with a handset if you were on the air.  I later found out that the One-x-Six could support a screener telephone on the second row if that was desired, but was not configured that way in most studios.

 Compared to the Symetrix, the One-X-Six sounded wonderful.  Answering the phone was as easy as punching the blinking line button, and you could press it again to “lock” to avoid accidentally hanging up on the caller.  If you wanted to conference multiple callers, you could simply “lock” the first line, grab the second line, and when you “locked” it, it would conference them together with the host. The “Next” button was indispensable for “Be the 10th caller” contests as it would automatically hang up the active line and answer the line that had been ringing the longest.  You’d typically hear, “Hi you’re caller number 2; Hi you’re caller 3, Hi you’re  caller number 4, …. Hi, you’re the tenth caller! Here’s what you won”.  The One-X-Six also provided hold music locally to the unit, so it was easy to play the appropriate station’s content depending on the station the caller called.  Ring alerting was done via an external ring/flash unit.

 The News Talk station was built about 10 years after the other stations, so the telephony was handled a little differently on that station.  Since the office system was fed with a PRI, it made sense to burn some of those channels for the News Talk which needed more lines than any other station in the cluster.  Calls would arrive on the Strata and would simultaneously ring the key telephones in both studios, as well as the analog lines on the One-X-Six, which were SLT’s off the Strata.  During normal operation, the screener in the production studio would screen the call on the bottom set of buttons on the One-X-Six and signal the on-air host which line was relevant. He would then hit the corresponding button on the top row and put the caller on air.

 You can see a One-X-Six in action

telosconsole

https://www.youtube.com/watch?v=0bna5-yTEgk?t=246

 If by some chance a caller called the office and needed to be put on-air, the office staff would transfer the call to the key telephone in the studio, then the host could hit “Transfer to Hybrid” and it would ring the Hybrid to arrive on-air.  The other studios would require the caller to hang up and dial the “hotline”.

 Ring muting was still accomplished the old fashioned way by physically disconnecting the speaker in the key telephone, but the flasher still alerted an incoming call if the mic was on-air.

 For special broadcasts, the cluster was also equipped with a Comrex Matrix codec.  Unlike the Hybrids, this system required a specialized unit in the field as well as in the studio.  The codec would dial the studio and a “modem” would auto-answer.  The Comrex pair would then negotiate an acceptable audio compression based on the quality of the phone lines. Think of it like VOIP, over a dedicated dial up connection.  If a suitable connection could not be established, the field unit could fall back and call the studio as a standard POTS call and act as a hybrid. In the later years we used this unit for baseball broadcasts and the quality was nearly as good as a Marti RPU (one way microwave audio link), but had the advantage of two way audio.

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Telephony in Radio Broadcast

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Jason, the guest writer on Avaya’s SIP agenda, has kindly given me some stuff to post while I’m out of the office at the Museum of Telephony.

Names have been generalized to protect the innocent.

 I’ve worked for two different radio companies in my employment history. With my interest in telephony, naturally I was interested in how the telephone callers got “on the air.”  Here are a few case studies on radio telephony that I’ve experienced.

 A quick definition for the un-initiated: In the radio business, a telephone hybrid is the piece of equipment that translates telephone audio (normally standard analog) into balanced signals to feed the audio console and does some active nulling to prevent too much of the announcer’s voice (which goes directly on-air via his microphone) from returning via sidetone on the telephone circuits.  A technical demo of a Hybrid

https://www.youtube.com/watch?v=k6k4gS-gkC4

 How not to do radio telephony:

The first company I worked for was a small two station cluster.  Its engineer was of the mindset, “Let’s not buy the correct equipment, I can do it just as well with parts from Radio Shack and some creative circuitry!”  For the purposes of this case study, I will ignore the second station which was fully automated and used a single line Gentner on a dedicated CO for any telephony on that station.

 The other station had an on-air studio, and a production studio. As you can imagine, the on-air studio ran the live broadcast, while the production studio was used to record content, commercials, shows, and other audio to broadcast later.  The entire company was served by a Comdial key system with 3 CO lines.  The Comdial functioned on 4 pair wiring, with the outer pair providing signaling, and the inner pair presenting as a standard analog line to each station, switched according to the buttons on the handset.   Both studios shared one Symetrix TI 101 Hybrid, whose “line” was selected by an ordinary low voltage DPDT switch. To use the system, you would grab the incoming line on the handset, and it would be automatically coupled to the Symetrix according to if the switch was set to On-Air or Production.  The Symetrix bridged onto the center pair of wiring going to each telephone, so whatever line on the set was selected, that’s the line you got on the Symetrix.

 Feedback elimination was crudely accomplished by a switch drilled into the telephone base which cut off the wiring from the telephone microphone. So when you were ready to put a caller on-air, you’d answer the call, get the caller ready on the handset, flip the switch, then talk to them using the on-air microphone, fed via the Mono bus on the console. As hybrids go, the Symetrix was about as basic as they came, with all parameters being controlled with knobs rather than with fancy automatic gain control.  Did I mention that the Symetrix was in the production studio so it was impractical to make real time adjustments to an on-air caller?

 Ringer muting when the mic was live was also accomplished manually in each set by a relay that cut off the speaker in the set.

This station also had one other funny quirk.  When a local vendor discontinued their satellite feed of the local sports roundup, we solved the problem in a most low-tech fashion.  Shortly before the roundup was to air in the morning, we’d call the station and ask the secretary to put us on hold. Then, we’d record the roundup off their hold music!

 If you needed to have something from the telephone live on-air and record something else, you were simply out of luck!   As you can see, this is how NOT to do radio telephony.

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Paging Tips

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Some people use a PBX or a KSU system in environments such as retail. And some instances, the most used feature or most liked feature of any telephone system is the ability to page.  However, excessive use and overuse of paging in inappropriate uses can drive customers away if you allow “Open Line Friday*” every day, or allow someone to page and page right after the last page.

*referring to an alleged theme on a major conservative talk radio show that supposedly callers can call in without a narcissist yepping in those 3 hours on such days.

I can’t tell you how Open Line Paging can drive someone with sensory disorders crazy.

Here’s the deal.

Instead of investing in expensive walkie talkies to talk behind the customers back, here is some guidelines in paging.

  • If you have a central extension (such as a customer service desk, where its always manned by someone monitoring the telephone), have that be the go to extension.
  • Instruct employees to dial zero to request a page.
  • Have a structured speech. Such examples
  • “[Person] Telephone call on [Pickup access code]”,
  • “[Person] please dial zero for the operator”
  • “[Person] Please call extension [number]”

Make sure the person is paging has an appropriate tone of voice, do not talk like a high school cheerleader, and do not page so you can hear yourself.

Also in this change of process, make sure you update your Class of Restrictions, Class of Service or COR or COS so the people don’t continue to page at their station or extension. Block access to paging and only enable it to the operator’s or central point of contact’s extension.

Automated paging also will turn away potential customers. Stores like Lowes and Kohl’s have automated paging systems where a user dials an extension to ring out to the automated paging. The real problem is when no one gets to the customer fast enough and the paging system sends more authority. And if you’re going to do “codes” outside of medical centers, reserve that for the walkie talkie. What does “Code 34” mean to a customer when its blasted at like 20db or something crazy like that?

9/11 Remembrance/AT&T Archives Throwback

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Every year the Museum will remember 9/11 until I die or the site dies, whatever comes first.

It’s something we cannot forget, because sadly people are forgetting and our children have no idea, and some people as young as 25 year olds are confused to see a New York once up in smoke and can’t understand how people fell out of the Twin Towers to escape the hell or go into hell, depending on how you look at it.

The Twin Towers had cheated disasters before. The bombings in February of 1993 impacted a lot more people, because each tower could hold up to 50,000 people of workers, visitors, travelers, etc. On the morning of 9/11, Lower Manhattan was considered very lucky compared to 1993, given it was a late summer day, a Yankees game went into extra innings due to a rain delay and people deciding to show up at work at 9:00 instead of 7 or 6 in the morning made the death count much lower than what could’ve been.

(In the 1993 bombings, the bombers tried to hit one of the 4 corners of the towers, and supposedly if they had hit one of the corners of the towers, it could loose it’s integrity immediately. Lower Manhattan was lucky too, as the bombers missed their target.)

Regardless between the three coordinated attacks, over 3,000 people died. AT&T, which was mostly an LD, data transport and cable TV services did not loose any of their workers, while other engineers did loose life.

According to AT&T, the switching system used in 2001, mostly of 5ESS or possibly DMS switching systems remained in tact. In fact because the switching systems were in a vault, the services (at least wired connections) could’ve worked if it wasn’t the wiring getting severed by the atrocious damage of the towers.

In the early 1970s, AT&T produced a video of the construction of the World Trade Center, and installation of switching equipment at the time (albeit an earlier generation of an ESS) and the days that followed with a typical business day in the Twin Towers. This film was released in 1976

Video: Nortel Ad – Circa 2000

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I was on a walk in my town for the first time in many months (feels like years in this long summer that never ends.) I passed by a biker going against me on the sidewalk who had a T-shirt that said  “What do you want the Internet to be?”

The T-shirt was by Nortel during the late 90s, the turn of year 2000. These ads ran from 1999 to 2000 when Nortel actually made their first major mainstream ad campaign that was outside the traditional trade papers. (I also bet The Beetles made some nice royalties beyond the typical SESAC dues!) This also followed after a major acquisition of Bay Networks, once located at the headquarters where Avaya is today in Santa Clara, California. Bay Networks had a large presence in Massachusetts (where the biker probably worked for or a friend of his or his spouse.) If you go on US Route 3 South before  Interstate 95 Route 128  you’ll see Avaya’s offices there. Prior to the Nortel acquisition Avaya got out of most of their New England offices and or plants.

This campaign didn’t help much because the rise of Cisco (I think in retrospect, the “rise” was inflated, through a lot of backroom deals, long lunch hours with CIOs and other weird things that made Cisco go to the top.)

Sadly, even though I dislike Nortel 9 times out of 10, it was watching a Greek tragedy that destroyed the company; first having a top heavy headcount (always a bad sign), second was a very rough transition from a mainframe type of technology (TDM) to less hardware dependent business (IP.) For whatever reason Cisco was able to sell tons of boxes and make a killing, allegedly in the first decade of the new Millenium. (Cisco’s success outside of IP Telephony is yet to be challenged publicly outside of niche blogs.) Factor in Enron-like accounting scandals and the infamous bankruptcy, Nortel had a lot of issues.

I’m not sympathizing with Nortel, many legacy telecom companies were unable to make the same profits in an IP/Internet based world. Well not until the concept of “cloud” based services where they could get a reoccurring revenue stream. Services were cut among all companies and even in the last 15 years, hardware maintenance was still needed, but good luck if you had a major bug and dealing with the vendor directly.

It was interesting to see still see things, like the biker in the Nortel swag in 2015.