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Old 17-12-2012, 10:27   #16
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Re: Working from boat/fax capabilities?

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Originally Posted by denverd0n View Post
Cellular service is line-of-sight. That means that it will definitely not work if you are well out to sea. You can, of course, get a mast-head antenna and repeater, to extend the range that you receive a cell signal. Even with that, though, I wouldn't expect to have service beyond a dozen or so miles off shore.
Pretty much my experience. In previous trips offshore I lost standard cell phone connections about 4-5 miles from the coast. I think a booster amp with antennae would double or triple that at most.
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Old 17-12-2012, 12:21   #17
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Re: Working from boat/fax capabilities?

Skip, cellular range is limited in a couple of "ignore the man behind the curtain" ways.

In order to manage the concept of "I can hit so many towers from here" and to tell the system which tower should answer which call, the system software is set up to look at the time delay between when it hits your phone, and when a response comes back. If that time delay is too long (Apollo....this is Houston....) the system is set up with the logic that there MUST be a closer tower, ignore the call. No matter how strong it is.

I'm told that most carriers have that set up for 16 miles, maximum.

And then there's the simple problem that cell phones are basically FM radios (that's not quit true) and each tower plays "capture the flag" and automatically serves only the #th strongest signals. It may be 10 calls, 100 calls, 50 calls...each tower has a limit and they are normally programmed to drop your call once they are full up, and a stronger signal comes in. There's a whole secret agenca to how they drop calls and deal with capacity, you may notice that you never get a busy signal on a cell phone--you just get shunted to voice mail. And outbound calls get priority over inbound calls. And it gets more complicated than that.

Of course the carrier has to have their towers' limited capacity "aimed" to cover the wasteland at sea (is that a non-sequitor?) when they could be covering users on land instead, as well. So...conventional logic about UHF radio communications? Doesn't cover all the bases when it comes to cellular range. You need politics for that.<G>

And don't tell the rubes, ergh, valuable customers. Math tends to upset them.
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Old 17-12-2012, 13:30   #18
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Re: Working from boat/fax capabilities?

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Originally Posted by hellosailor View Post
Skip, cellular range is limited in a couple of "ignore the man behind the curtain" ways.

In order to manage the concept of "I can hit so many towers from here" and to tell the system which tower should answer which call, the system software is set up to look at the time delay between when it hits your phone, and when a response comes back. If that time delay is too long (Apollo....this is Houston....) the system is set up with the logic that there MUST be a closer tower, ignore the call. No matter how strong it is.

I'm told that most carriers have that set up for 16 miles, maximum.

And then there's the simple problem that cell phones are basically FM radios (that's not quit true) and each tower plays "capture the flag" and automatically serves only the #th strongest signals. It may be 10 calls, 100 calls, 50 calls...each tower has a limit and they are normally programmed to drop your call once they are full up, and a stronger signal comes in. There's a whole secret agenca to how they drop calls and deal with capacity, you may notice that you never get a busy signal on a cell phone--you just get shunted to voice mail. And outbound calls get priority over inbound calls. And it gets more complicated than that.

Of course the carrier has to have their towers' limited capacity "aimed" to cover the wasteland at sea (is that a non-sequitor?) when they could be covering users on land instead, as well. So...conventional logic about UHF radio communications? Doesn't cover all the bases when it comes to cellular range. You need politics for that.<G>

And don't tell the rubes, ergh, valuable customers. Math tends to upset them.
I am vaguely aware that there is a pretty complex system of hardware and software behind cell tower operation but your details add some clarity to the situation. Guess one of these may be behind one thing I observed on my trip down the coast to FL. We made three legs of the trip offshore and each time all three of us would loss signals about 4-5 miles offshore and we were on three different carriers. However, even though I could not connect I would have a 5 bar signal on the phone even 12-15 miles offshore. I was assuming that was due to the low power of the handset (I think 1/8-1/4 Watt typically) compared to the tower transmitter but perhaps the lack of connection was due to some algorithm in the connection software or perhaps the receiving antennas on the tower were directional towards land.

Regarding boosters, I have read reports from users on land reporting connections up to 15-20 miles with various systems. Not sure if offshore would give the same results.

Another comment, I always wondered how the passengers on 9/11 were able to make cell phone calls from the planes since I always thought, as you say, cell systems would ignore a signal that hit so many different towers at the same time.

Which reminds me of a pet peeve. If commercial airliners are so damn sensitive that you have to turn off your cell phone to prevent them from crashing then how come the terrorist don't get on the plane with three or four cell phones secretly switched on in their pockets and crash planes right and left? OK, rant over.

Regarding cell transmission mode, I hadn't thought about it but guess FM is the case, in addition to digital encoding and spread spectrum frequency.
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Old 17-12-2012, 13:47   #19
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Re: Working from boat/fax capabilities?

"Another comment, I always wondered how the passengers on 9/11 were able to make cell phone calls from the planes since I always thought, as you say, cell systems would ignore a signal that hit so many different towers at the same time."
Yeah, well, at first the airlines were all big into "Airphones" and they had a vested interest in telling any story that would get you to use their phone at $5 a minute instead of using your own cell phone. Funny thing.
I haven't seen an airphone lately but have seen schemes that will allow you to use your cellphone on the plane--for a price--using a picocell the airline has on the plane. Hmmm...money again.

"Which reminds me of a pet peeve. If commercial airliners are so damn sensitive that you have to turn off your cell phone to prevent them from crashing then how come the terrorist don't get on the plane with three or four cell phones secretly switched on in their pockets and crash planes right and left? OK, rant over."
I've got a better one for you. Your cell phone has a maximum power of 600mW, that's six tenths of one watt, and you can't make it work that hard unless you hit 611 or 911 (911 mandated to use full power, 611 optional but the carriers want you to be able to reach them) or unless your phone really is hunting for a signal.
Now, if 150 passegners all lit up their phones at max power all at once...that's still only 150*.06 => 90 watts total, right?
I'm in deadly fear, because if a couple of watts could bring down a plane, one raghead with a refocused microwave oven, putting out a thousand watts or more, damn well out to be able to bring down every aircraft leaving the runway, when it is low, slow, and full of fuel.
Oh, wait, that's not a problem? A thousand watts, two thousand watts, not a problem? But my cell phone is?
You'll be relieved to know that the FCC have recently and formally petitioned the FAA to revise their rules in the belief that cell phones pose ZERO danger and a great deal of convenience to passengers.

FM, in the sense of the "FM capture effect" the same way your FM radio tends to lock into the one strongest station, rather than bringing in two or three at once the way an AM radio will.

Now, if you are an emergency responder, you can also pay (about $10/month plus $2/mnute) to get a bit flipped on your cell phone's identification number. In which case the systems are all mandated, by law, to take calls from that cell phone even if it means dropping other phones, from less blessed users.

Shhh! Ignore the man behind the curtain! (And those prices really help ensure a lot of responders don't crowd the system, either.)

--The water is always bluest in the aircraft lavatory.

And hey, have you ever noticed that the head on an Airbus, any Airbus, would make a really great marine head?! I really wanna get me one a those.<G>
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Old 17-12-2012, 14:38   #20
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Re: Working from boat/fax capabilities?

Quote:
Originally Posted by hellosailor View Post
Yeah, well, at first the airlines were all big into "Airphones" and they had a vested interest in telling any story that would get you to use their phone at $5 a minute instead of using your own cell phone. Funny thing.
I haven't seen an airphone lately but have seen schemes that will allow you to use your cellphone on the plane--for a price--using a picocell the airline has on the plane. Hmmm...money again.
Ah yes, the old air phones, more expensive than making an overseas call from a hotel. Used one exactly once, when my daughter was 7-8 years old and thought it was cool to talk to daddy while he was on an airplane.



Quote:
Originally Posted by hellosailor View Post
You'll be relieved to know that the FCC have recently and formally petitioned the FAA to revise their rules in the belief that cell phones pose ZERO danger and a great deal of convenience to passengers.
I had read that but so far the only change I have seen in several years is that they let you talk on your cell phone while taxiing to the gate.



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--The water is always bluest in the aircraft lavatory.
You would have to point that out. I might have to change my signature line.

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Originally Posted by hellosailor View Post
And hey, have you ever noticed that the head on an Airbus, any Airbus, would make a really great marine head?! I really wanna get me one a those.<G>
Never noticed the heads but I did notice that when you pull an A300 up to the gate and shut down the engines you hear a noise that sounds like a 20' hack saw chopping the wings off. Someone told me it's the hydraulics but doesn't sound like any hydraulic part I know about.

So what is the Airbuss head like? Something other than the standard vacuum flush system? Should be easy to implement on a boat. Just need a large, high capacity vacuum pump linked to a giant holding tank.
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Old 17-12-2012, 14:45   #21
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Re: Working from boat/fax capabilities?

There's another idea. Postcard. I used to use a service called AMAZING MAIL (google it). You can upload a photo, and they make and mail the postcard for you (for a small fee and the postage, of course). See if they are still in business.
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Old 17-12-2012, 14:52   #22
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Re: Working from boat/fax capabilities?

Use netfax/efax for free or 14 bucks a month and get a cheap scanner/printer combo. Cool thing is you can send and receive faxes by email so you can queue them up until you get to internet for send and recieve.
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Old 17-12-2012, 14:55   #23
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Re: Working from boat/fax capabilities?

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Which reminds me of a pet peeve. If commercial airliners are so damn sensitive that you have to turn off your cell phone to prevent them from crashing then how come the terrorist don't get on the plane with three or four cell phones secretly switched on in their pockets and crash planes right and left? OK, rant over.
Because they're not telling you the whole truth. Most airline emergencies happen on takeoff, landing, or under 10k feet. In the event of an emergency, the flight attendants need to communicate with you and with each other. Having 200 people talking on their phone, playing their video games, having their headphones stuck into their ears, watching a movie on their laptop, etc, makes communication harder. However, if they say "hey, keep your cell phones and electronics off cause we might need to talk to ya if we're gonna crash" doesn't really make the passengers feel safe.

In the case of cell phones, it's my understanding that *sometimes* they will work in the air, but who really wants sit on a plane with 8 different people carrying on cell phone conversations around them?
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Old 17-12-2012, 15:43   #24
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Re: Working from boat/fax capabilities?

skip-
The Airbus heads are just simple and elegant. Nice lightweight stainless, good size bowl, no odd shapes to catch dirt inside or out. Big enough for grown-ups. Same old vacuum flap at the bottom, and the profile of the bowl makes it likely that whatever goes in will hit the bottom without clinging to the sides. Not that I'm an Airbus fan, but they're slowly earning my respect.

bg,
I'm not sure there's any advantage in having everyone hear the emergency announcement at once. That's flat out contra-Darwinian. The folks who fly in thongs, effectively barefoot? Do I really want them to find out about the emergency and clutter up the exit in front of me? The folks who can't figure out how to put their rollers (ROLLERS?) in the overhead bin...I have seen these folks, when they get into the exit itself they will stop to look around and change their sunglasses, the same way they do in every doorway.

EU, the exits always open out, and stay out. By law. US? The wing hatches are supposed to be pulled IN and laid on the seats, partly obstructing the exit row. I had one stew explain to me that's because the hatches won't fit out the holes, you have to pull them in. (Geometry genius, huh?) Someone at Boeing suggested to me that US airline policy tends to reflect the price of replacing one of those hatches, and the repairs to the wing it lands on, if you just eject the hatch and clear the exit aisle. In the unlikely event I ever have to open one of those exits, I know where the hatch is going and I'll just swear gremlins snatched it.

Matter of fact, last time I flew a redeye, I noticed the shades were all down, pretty much all the way. I know they used to ask passengers to open them before takeoff and landing. I wonder...did I miss another memo, or was someone lying to me again? Or maybe because it was an Airbus, they work the shades the opposite way.<VBG>
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Old 17-12-2012, 16:28   #25
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Re: Working from boat/fax capabilities?

okay....I'd like to tag onto the thread if no one minds.
can someone shed some light on boosters, antenna etc. to extend wifi and cell range?
the YC i belong to has wifi and **sometimes** it reaches the mooring field.
cell is also spotty at best
I have no idea what to look for....i'm assuming the wifi and cell antennas are two different things?
Thanks
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Old 18-12-2012, 10:43   #26
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Re: Working from boat/fax capabilities?

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have you ever noticed that the head on an Airbus, any Airbus, would make a really great marine head?
I have noticed that. I'll bet they're available.
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Old 18-12-2012, 10:51   #27
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Re: Working from boat/fax capabilities?

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okay....I'd like to tag onto the thread if no one minds.
can someone shed some light on boosters, antenna etc. to extend wifi and cell range?
the YC i belong to has wifi and **sometimes** it reaches the mooring field.
cell is also spotty at best
I have no idea what to look for....i'm assuming the wifi and cell antennas are two different things?
Thanks
Yes, they are two different things although some smart phones will connect to wifi. Quick, easy, plug&play, good deal, good people, good tech support buy a wifi booster from islandtimepc.com
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Old 18-12-2012, 10:52   #28
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Re: Working from boat/fax capabilities?

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I have noticed that. I'll bet they're available.
I'll bet they are too but also bet you better bring your big wallet if you go shopping for one of these.
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Old 18-12-2012, 10:54   #29
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Re: Working from boat/fax capabilities?

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Because they're not telling you the whole truth. Most airline emergencies happen on takeoff, landing, or under 10k feet. In the event of an emergency, the flight attendants need to communicate with you and with each other. Having 200 people talking on their phone, playing their video games, having their headphones stuck into their ears, watching a movie on their laptop, etc, makes communication harder. However, if they say "hey, keep your cell phones and electronics off cause we might need to talk to ya if we're gonna crash" doesn't really make the passengers feel safe.

In the case of cell phones, it's my understanding that *sometimes* they will work in the air, but who really wants sit on a plane with 8 different people carrying on cell phone conversations around them?
That all makes sense.

Don't really care if everyone else on the plane wants to talk, I usually use ear plugs or a noise cancelling headphones so it's like they aren't there anyway.
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Old 18-12-2012, 11:20   #30
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Re: Working from boat/fax capabilities?

skip-
I suppose we're tottally OT...no, wait, one quarter of all cell phones supposedly get replaced after being dropped in toilets, so maybe we're not OT. Or maybe a mod could split these off.

There's no obvious brand name (dumb europeans, missing a great place and chance to sell more advertising ?!<G>) and for all I know, someone at Airbus has them custom fabbed along with all the other interior parts on the aircraft, rather than purchased from a supplier.
I mean, aside from Boeing and Airbus, there aren't too many "lookit the big plane!" manufacturers left out there, and Antonov and Ilyushin just might not be buying the same components.<G>
A good stainless lobster pot, a nice tight lid, might not even need the Lavac-style gaskets. Ya think?
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