[Telecom] Reverse 911

It's worse than that -- what if a given tower covers _both_ part of the area you want to reach -and- an area you do *not* want to reach.

What about a phone that is 'roaming' in the area of the R911 call-out? Is R911 going to make a _long_distance_ call (who pays?) to the number associated with -that- phone?

'Landline' numbers within a particular geographic area are fairly static. they change only when somebody adds/drops service within that area. for any given number, the average time between changes will be measured in _years_.`

'cell' numbers are *much* more dynamic -- average time between changes (for any reasonably compact geographic area) will be measured in hours, *at*most*, with a heavy skewing towards some small number of minutes. given this, the volume of 'database updates' utterly swamps the call-out usage.

It's one thing if there's a phone-number update every 3 years, on average, for a service that is used 2-3 times a year.

Its something _quite_ different, if there's an update every 8 hours, on average, for the same usage.

Among other things, in the first situation, if you call out from a database that is 'a few months old', you'll get a fairly _small_ number of 'errors', defined as: 1) numbers called that are no longer in service 2) numbers called, at a location _outside_ the R911 call-out area 3) numbers *NOT* called, at a location inside the R911 call-out area.

Use a database updated weekly, and the error probability goes _way_ down. Use daily (end-of-business day) updates, and you can probably count errors on your fingers.

For the second situation, unless you have 'real-time' updates of the database, the error rate will be several (probably _many_) orders of magnitude higher. higher. This, obviously, requires continuous tracking of -all- powered on cell-phones -- *not* just those that have active conversations in progress.

For GPS-based location-reporting phones, they now have to report the GPS data with every 'poll'/'keep-alive' packet from/to the tower.

For tower-based direction-finding, multiple towers have to co-ordinate on every phone-originated packet. This may well over-tax the capabilities of the tower-based system -- a "Too many phones, not enough time" problem. If so, there is no easy solution for _that_ issue.

This kind of a system (R911) really works best on an "opt-in" basis. Let the phone owner _choose_ what areas they wish to receive emergency alerts for. People in care-giver roles may well _want_ to receive alerts for places where _they_ are not at, at the time of the alert. Similarly, people at work may well want toe receive alerts about things 'at home'. This methodology works equally well for landlines, cell-phones, and/or VoIP.

Thanks for raising these points! I've forwarded them to various parties.

THe ideal would be that a reverse 911 would go to all phones in the geographical area, including those cellphones that just happen to be driving through the area (or visiting): "be on the lookout for a small boy in a red jacket who may have wandered away from home or may have been abducted..."

Does a cell tower know which phones are within its range?

***** Moderator's Note *****

Is it just my incipient paranoia, or is this a setup for voice spam? If cellphones are made with the capability to receive an "all stations in range" broadcast, won't hucksters buy and use unlicensed cellular transmitters?

"This urgent traveler advisory is brought to you by the East Side Garage at 37th Street! Welcome to New York! While you're here, check out Elaine's restaurant and Linda's boutique and Runway 69!"

Bill Horne Temporary Moderator

(Please put [Telecom] in the subject line of your post, or I may never see it. Thanks!)

Dear Bill,

I think we all appreciate what you're trying to accomplish with this "insert {Telecom]" request (not to mention appreciating your filling in as Moderator!).

A downside, is that (for me, anyway), a lengthy list of new postings containing a bunch of lines on different subjects with differing formats, e.g.

-- [Telecom] Some subject . . . -- Re: [Telecom] Some subject . . . -- [Telecom] Re: Some subject . . . -- Some subject . . . -- Re: Some subject . . .

become very hard to scan for the posts one wants to read -- and also totally messes up the threading mechanism that's so useful in many newsreaders.

Alternative ways to do this?

1) Could you have your system automatically filter out the [Telecom] strings in posts once you've received them (and put a standard number of space between "Re:" and "Some subject"?

(Downside: Requires programming, and doesn't remind people to put in the {Telecom] string.)

2) Everybody put the {Telecom] string at the _end_ of the Subject line.

(Might make lists of posts easier to read, and let auto-threading mechanisms work OK?)

3) Require instead some similar code phrase in some other Header line?

4) Other ideas?

Thanks again.

***** Moderator's Note *****

I can filter out the [Telecom] strings, but that means those composing replies would have to manually add them again. I think most readers would rather not. The "Re:" prefix in replies is inserted by the newsreader, and the number of spaces after it should always be one, unless the original post had spaces before the subject, in which case the post was created by a borken newsreader or an ill advised poster. I have been manually adding "[Telecom]" to subject lines for some posts (Hi, Lisa!), and if I put in too many spaces that's my fault.

I don't care if the [Telecom] string is at the end of the subject line: the logic will detect it whereever it is. Threading isn't affected either way, since it depends on the Message-ID and In-Reply-To headers. Sorting by Subject, however, _would_ be easier with the [Telecom] at the _end_ of the subject line.

Requiring a similar phrase in some other header wouldn't work, because:

A. It assumes that readers have newsreaders which preserve headers, so that replies will _also_ have the header. B. It assumes that news servers don't delete any headers. C. Very few news readers have the capability to add header info to posts or replies, especially non-standard "X-" headers.

Other ideas:

A. Require all submitters to sign their posts with PGP/GPG, and accept only signatures with keys on the public keyservers. B. Require all submitters to sign their posts via X.509 certificates issued from a well-known certificate authority such as Thawte or Verisign. (For a free email signing certificate, visit

C. Have a special version of American Gladiator during sweeps week, with real weapons and only spammers competing. I'd _pay_ to watch!

Bill Horne Temporary Moderator

(Please put [Telecom] in the subject line of your post, or I may never see it. Thanks!)

Comment: That kind of thing does *NOT* justify calling "everybody in town". The _only_ things that such a call-out should be used for is something that is an *IMMEDIATE*THREAT*TO*LIFE*AND*LIMB* of _everyone_ in the called area. Things like: a dam is about to break, and everyone must evacuate the area, or a tornado warning. It's _probably_ justified if the local water system has been contaminated, and tap water needs to be boiled before drinking.

There are 'other applications' for this kind of system, for reaching _specific_ constituencies -- e.g. parents of children at a specific school. This is, by definition, a _selective_ call-out, and the affected parents should be able to specify _what_ number(s) they want to be notified at. Which means this is, effectively, an 'opt in' system.

All that said, *IF* you settle for 'geographical area' being defined by 'cell' boundaries, regardless of political subdivisions, the idea is barely within the realm of reason.

If you insist on following municipal/county/whatever boundaries, the cost will be _ASTRONOMICAL_.

That question doesn't have a simple answer.

It knows the 'network ID information' about phones that have recently communicated with it.

It does *NOT* know if they are still 'reachable' -- the user may have turned it off, it may have moved into a cell belonging to a different carrier, etc.

When a tower determines it has become the 'preferred' communication path for a given phone, it notifies the 'home base' for that phone, that said phone in it's service area and that 'home base' should relay information for that phone through this location.

The tower does -not- know when it is _no_longer_ the preferred path -- it doesn't have to. If/when some other tower becomes preferred, _that_ tower notifies 'home base', and home base then knows how to route things appropriately, without needing any notice from the 'no longer preferred' system.

Thus, when 'home base' needs to contact a phone, the first thing it does is send an "Is you dere, Charley" message to the 'last known address' of the phone, to see if it gets acknowledgement.

When the cell tower gets that message, it broadcasts an instruction for the specified phone (identified by the network ID info only) to speak up.

If there's no response, an error message goes back to home base, to the effect that the phone is presently unreachable "here".

Relevant to -your- application: the 'tower' doesn't know/care when somebody leaves it's area.

It does not maintain a database of what phones _are_ in it's area. (It doesn't need to, that information has been pushed to the 'home base' for each phone and that is the only place that needs to store the info)

It has to figure out who 'home base' is for the phone: a) when it becomes the 'preferred' path for that phone b) when the phone -initiates- an outgoing call (or other communication via the servicing carrier.

Aside: TTBOMK, "triangulation"-type direction-finding is _not_ done automatically/continuously for every phone in an area.

Triangulation requires near-simultaneous data from several cell towers, involves additional (not inexpensive) resources, has limits on how fast it can determine location for a particular phone, and thus, is limited as to _how_many_ phones it can establish locations for in a given amount of time.

I'm going to point out, again, that _all_ of these 'problems' go away if the phone owners have to 'opt in' to notifications for given locales.

I'll ask you to consider whether _you_ want to receive calls at __2AM__ asking you to look for the little boy in the red jacket.

For somebody that works 3rd-shift, a "day-time" call-out is equally disruptive.

If the 'word' that needs to get out is _really_ important, there is a system _already_ in place, that will reach *everyone*, regardless of whether or not they even have a phone (cell or land-line). I speak of the 'civil defense' sirens.

Put the information on a government web-page, the cable-tv channel, and a canned message that people can phone in and listen to.

Then have a 'special' signal pattern on the sirens -- something like 2 'whoops' followed by a 'steady', repeated several times -- to tell *everybody* that there's an emergency notice.

I can guarantee you that someone will want to use the system for less than literally earth-shattering messages.

At first, these will be 'urgent' messages but not 'super critical'. For example, a lost kid, or a very bad fire in one area.

Then it will degrade to 'important safety' messages, such as a precautionary warning to be careful check on the eldery on an extremely unusually hot day or a winter advisory on an extremely unusually cold heavy snow day. For example, say it will be 100 degrees in an area that rarely goes above 85, or 0 degrees in an area that rarely goes below 20. The public safety officials will argue that these extreme temperatures warrant use of a broadcast message to save lives.

I don't object to such systems, but I would want them utilized only for the absolutely most serious disasters, such as an evacuation due to a chemical spill of poisonous gas. Things like weather alerts can be reported by normal radio stations.

But I don't want to be bothered by non-critical messages, and I know I will. That's just human nature. If there was say an ice storm, citizens will complain afterwards that they should've used the alert system.

Let me add something else. My area has flooding problems from the river. Sometimes there is long warning (24-48 hour), sometimes only a relatively short warning (8 hour). The number of homes near the river, relatively to the total number of homes reachable by the cell towers is a relatively small proportion. In an 8 hour situation, should every phone be called?

Natural disasters that would justify such a system don't follow political subdivisions. Using cell boundaries makes sense if the danger is bad enough. People outside the area would need to know to stay away from the area.

For cell phones, yes.

No, I do not, and you make a good point.

True. Or someone that is home sick, or caring for a sick person.

I strongly support a siren. However, I don't know if many still exist. Years ago Phila tested its sirens every Weds at noon for 30 seconds. I don't know if they still do that or even have the sirens in working order. Newer suburban towns don't have sirens.

Our firehouse had a mechanical siren which was replaced by an electronic one. It isn't as loud or piercing, esp as it went up and down in pitch.

People would need to be trained in hearing a siren what to do.

Good ideas.

Adding to the end of the subject line (as I am doing here), is the easiest.

I would ask that you NOT filter it out, so I don't have to go back and keep adding it when I reply to messages.

.... all excellent points. Thank you.

The PEG channel is in fact my own role in all this.

Since the days of fallout shelters is pretty much over, I don't know what it takes to create a new siren signal - in fact, I haven't known for decades what any variants are! The Only one I use is the noon-signal ;-)

snipped-for-privacy@bbs.cpcn.com wrote in news:9cf9ae6c-571d-4268-90dc- snipped-for-privacy@i12g2000prf.googlegroups.com:

Just strip it out anyway, then place it back in the preferred (end of subject) location. Watch out for subjects like this one, though!

snipped-for-privacy@bbs.cpcn.com wrote in news: snipped-for-privacy@e10g2000prf.googlegroups.com:

I remember in the 1950s and 1960s we had a card describing the types of warning and alert signals. It was on the wall next to THE phone. One instruction was "tune to 640 or 1240 on your AM radio dial." The signals at the time in that town were on the air horns at the fire station.

We now have electronic siren-voice systems around the area, because we are within a ten-mile radius of a nuclear power plant. (That's nukuler, if you are GWB.)

I remember those cards. There were different siren codes for different situations.

On radios, 640 and 1240 had a little triangle on the dial to indicate they were the emergency stations.

They still have the 'emergency broadcast alerts', with a very annoying tone for tests, but 640/1240 haven't been mentioned in years. I think once in our area they used it for real for very heavy thunderstorms.

I don't see too many 'fallout shelter' signs anymore. I used to think they were air-raid shelters, not realizing the difference between air raid and fall out protection. I wonder if those places had air filters and pumps for outside air, otherwise, I think radioactive airbourne particles would've been breathed in.

Many of the stored food and water cannisters have been destroyed, some cannisters are painted and used for other purposes. We use them for paper recylcing bins.

In the late 50's or early 60's there was a nationwide test of the system, I seem to remember it worked fine except in LA, someone I believe dialed a wrong number and the alert never got to Los Angeles, I do remember the headline in the newspapers saying rock please in LA while alert goes on.

You still see the signs in older areas line in downtown Los Angeles, I know that the old Red Car Barns near the 5 Freeway was used by Los Angeles County for storage.

In the early 1950's President Truman established CONELRAD (CONtrol of ELectromagnetic RADiation) as part of the Civil Defense system. The plan was that, as the Russian bombers drew near, most radio stations would broadcast an advisory message and then cease transmitting. Two stations, one on 640 Kilocycles and another on 1240 Kilocycles (KiloHertz hadn't been thought up yet!) would begin low power broadcasts providing further advice to citizens. The low power was supposed to render the Russian's radio direction finders useless so they would have no clue as to where to drop their bombs!

Radios of the time had the little circles with triangles and the letters "CD" at 640 and 1240 as mentioned.

CONELRAD faded away with the advent of ICBMs which didn't home on AM radio stations for guidance - they used various forms of internal navigation to determine which citizens would get an early trip to the promised land.

He pronounces it "nukuler" because he confuses nuclear with unclear.

What I recall is that *all* radio stations were supposed to broadcast on

640 and 1240 so that direction finding based on commercial radio transmitter locations would be rendered useless because the normal frequencies would not be used.

I have no idea whether that was the plan or not.

***** Moderator's Note *****

ISTR that the plan was for one or two stations in each market to have the capability to _switch_ to those frequencies so that the rooz-keys couldn't home on a known location.

Then again, they say that the memory is the second thing to go...

Anyone out there know for sure?

Bill Horne Temporary Moderator

(Please put [Telecom] in the subject line of your post, or I may never see it. Thanks!)

Perhaps both of you have forgotten that Jimmy Carter also mispronounced that word. Acknowledging that point would screw up your cheap political shot.

***** Moderator's Note *****

Jimmy Carter was a Naval Officer trained in nuclear submarines. He was, therefore, entitled to pronounce the word as he chose.

George Bush, Jr., however, should set an example for the less gifted amoung our nations schoolchildren and make an extra effort to form the word in the correct manner.

Bill Horne Temporary Moderator

(Please put [Telecom] in the subject line of your post, or I may never see it. Thanks!)

There's more on Conelrad at

. In the early 1970s, I worked at a station on 1440kHz. The transmitter had a crystal to change to 1240kHz and red paint marks on the output tuning coils where we'd move the coil clips for operation on 1240. The normal 1440 tuning positions had blue paint.

The Wikipedia article describes the tone and carrier interruption alert method of Conelrad. That was still in use with the Emergency Broadcast System in 1970. When we put a new transmitter on the air, an EBS test was scheduled the first day. Momentary interruption of the carrier tripped the main breaker for the transmitter, taking the station off the air until I could get to the transmitter.

Later, the tone and carrier drop alert was replaced with a two tone alert where a combined 853 and 960Hz tones were transmitted for about

25 seconds. This would unmute receivers.

This was later replaced with the Emergency Alert system. This system transmits audio frequency shift keyed data carrying the emergency information. It identifies the type of emergency, the area of concern, the start time, and the end time. The 853 and 960 Hz tones are still used in real emergencies (not tests) to unmute existing receivers. The AFSK data bursts are popularly called "duck farts."

The FCC is currently considering replacement of the EAS system.

The FCC rules on EAS are at

Harold

snipped-for-privacy@hotmail.com (1100GS_rider) wrote in news:1ic86hb.1s8e6x31ugsurkN% snipped-for-privacy@hotmail.com:

I do not see my original comment as "cheap" nor "political," except that almost every time I hear the wourd mispronounced, it seems to be by GWB. As for the second comment (not mine,) I have heard that joke from a professer of nuclear physics, who had a nametag which said "Unclear Physics."

It was no less grating to me to hear Jimmy Carter mispronounce it. Persons in that position, with as many advisors as they have, should mispronounce a word in public at most once.

I don't think that *all* stations would be required.

Can you just imagine the necessary equipment to load out the transmitter and antenna for a frequency not originally set for.

Sorry, but that is 'revisionist history' at work.

In the event of an attack, ALL stations that were not part of the CONELRAD alert network would cease transmitting.

Those that _were_ would adjust their transmitter to the assigned frequency (if needed), and transmit according to a pre-arranged *INTERMITTENT* schedule, at full power. Stations were selected such that _several_ transmitters covered any given geographic area on either frequency -- by alternating between those stations, 'continuous' information could be provided to the public, _without_ providing a 'reliable' fix for RDF-based navigation.

On _at_least_ one occasion, the "This is not a drill" alert message was sent over the notification channel to all radio/tv stations, _in_error_, at the time of the 'regularly scheduled test'. Reaction was mixed -- some stations shut down as called for, others "assumed" it was a test, because of the time.