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Old 26-08-2009, 16:19   #46
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Hello everyone, just a couple of things to note.

Sat. internet is never fast and will never be fast using our current mothods of data transmission. As it turns out the major bottleneck is the amount of time it takes the data packet sent from the clientside (boat etc) to the satellite, and from the satellite to the ISP. Remember, internet data transfer is a conversation. You dont get to speak your bit until the other side has had a say, this is why close range wireless has such a higher transfer rate. Radio waves just cant complete with electricity and light in terms of speed over sheer distance. It takes about a quarter a second for a radio signal to reach space from the ground, and since it needs to come back that is a full half second latency not even including ANY computing. In internet land this is VERY slow.

My point is, we can stop pointing out that satellite internet is slow because...well...its a given.
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Old 26-08-2009, 18:17   #47
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Internet at Sea

Quote:
Originally Posted by Event_Horizon View Post
Sat. internet is never fast and will never be fast using our current mothods of data transmission........

Radio waves just cant complete with electricity and light in terms of speed over sheer distance............

It takes about a quarter a second for a radio signal to reach space from the ground, and since it needs to come back that is a full half second latency not even including ANY computing.

Huh????

Event_Horizon,

Please forgive me for interupting this discussion with the facts.....but.....

I've made my living in commercial satellite communications for 25+ years (own and operating my own company, as well as consulting worldwide.....), and I just cannot let this pass.....

In reverse order:
1) Transmission latency for Iridium Open Port is VERY low.....
Since their satellites orbit at an altitude of 485 miles and ultilize inter-satellite linking/connectivity to pass your transmission along its route, until downlinked to a suitable ground station (loacted as close to destination as possible), where it is then routed as any other IP data.....
One-way transmission latency is only 2 milliseconds (that's 0.002 seconds).....
If you add another thousand miles of transmission range (from satelite to satellite, etc.) and then back down again......you'll get an average round-trip lantency of approx. 9 milliseconds (that's 0.009 seconds).......

2) Transmission latency for geostationary satellites (INMARSAT / Fleet Broadband) is half what you wrote.....
Even taking into account the slant range (equatorial altitude of 22,300 miles + extra miles to typical user) of approx 23,500 miles, the one-way transmission time is about 1/8 of a second (actually 0.126), giving you a round-trip lantency of 1/4 second, not 1/2 second....

3) Radio waves travel at the speed of light.......

4) I'm not even going to get into on-board satellite processing of data / packets.....and these smart satellites that send many different packets to many different destinations.....
Using on-board packet switching and data processing reduces latency even more, and allows for higher BER with lower S/N, etc. etc. etc.....

All of my post above is fact.....not opinion......


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This last part are my thoughts......mostly facts, but some opinion.....

5) You write that satellite internet is never fast and never will be.....
Hey, that may be your opinion.....but, compared to what?????

Compared to 802.11 data rates, yes.....
But compared to a telephone fax transmission, or other commonly / daily used services, and your comment just doesn't hold up well.....

Have you read the discussion I posted the link for earlier????
If you had, I think you'll see my point....

Quote:

1) My crystal ball is not too clear.....

2) Change, Progress, Hope, etc. are all relative....


If you keep in mind item #1, I'd like to comment on #2.....

a) Back in the good 'ole days, of the 1970's and 80's.... phone calls while at sea were as much as $10/minute on HF radio (falling to the bargain price of ~ $5/min in later years), and those via INMARSAT (standard A) were $11 - $12 per minute., and these were BIG and power hungry terminals (~ 4' - 6' in dia) costing 10's of thousands of dollars.....

There was no internet, so "data" was a slow telex......which also was VERY expensive.....

{ I have personal experience trying to place phone calls from Europe back to the US, in the late 1970's (No direct-dail phones back then in most of Europe).....In many areas, it was a laborious task at best, and cost upwards of $25, plus a few dollars per minute.....I can recall waiting an hour in the "telephone office" in some towns in Greece, for the call to get through (and then sometimes we'd get cut-off in mid-conversation)....and in coastal Turkey, getting a call thru to the US proved unsuccessful over a couple of days, so I simply made a few calls with AT&T via HF radio stations WOO and WOM (Ocean Gate, NJ and Miami/Ft. Lauderdale, FL), right from the boat.....yes they were pricey, but they got thru and were easy-peasy!!!! }

{And, as a comparison, just about 5 years ago here in Florida, 64k ISDN lines cost $150 - $200 per month, with long-term contracts and a few hundred for equipment, etc...and, dedicated high-speed lines were 1000's of dollars per month.....}

b) Nowadays, you can place phone calls via WLO and KLB (www.shipcom.com) on HF radio for $1 / minute.....with no monthly charges / subscriptions......and no equipment to buy (assuming you already have an HF radio)

You can also send / receive data at low speeds very cheaply (or for free) via HF radio.....
(and if you can accept the slow speeds of PACTOR I, you do not need a $1000 SCS modem....)

You can also make phone calls via Iridium for $1 / minute.....
And low speed data isn't too pricey via Iridium, either....

c) With further advances in the past year or so.......from Iridium Open Port and INMARSAT's Fleet systems, etc.....
We now have high-speed data at somewhat reasonable rates, worldwide.....
(Remember a 64k ISDN line here in Florida cost $150 - $200 per month, plus a few hundred for the equipment and a low-term contract, just 5 years ago!!!!!)

d) Over 70% of the planet is ocean, but virtually nobody lives there.....so who designs, builds, launches, etc. communications services for areas with few (or NO) people????
INMARSAT did.....and they did a great job....
Iririum did, and they have done an incredible job!!!!!
Shipcom did, and still provides great service....
Sailmail did with data, and also provide services.....
With ham radio, WinLink provides good data services.....
AT&T did as well (HF radio)
Other companies have come and gone as well, providing voice and data comms to remote areas and across oceans, etc...

e) I do NOT mean this in anyway personal....since I'm just like everyone else, this applies to me as well.....
The main problem is the US (and to lesser extent EU and Japan/China/Korea) consumers always assuming they will get MORE for LESS.....and if not, many will state "that company is a rip-off!"......when in fact it is simply providing great service for a price that allows it to continue its business and continue to provide services to their customers......

This discussion can lead directly to corporate greed, consumerism, media hype, corporate-owned media, lack of fiscal responsibility of both publicly-traded companies / private companies, and especially governments, etc. etc......


3) In a nutshell, in MY opinion we actually do currently have "reasonably-priced" broadband services available in remote areas and across oceans......
Yes, it is pricey, but it is reasonable......


4) So, finally, will we have cheaper services in the future???
YES......but please remember, just what "cheap" means, is relative.....

Sorry about my bluntness, I mean no offense, just wanted to dispell the misinformation....

John
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Old 26-08-2009, 19:30   #48
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You are probably right, after all I'm a mechanical engineer and thus...don't work on satellite networking. First off let me adjust your 3rd point.

3) Radio waves move at the speed of light...but only a complete and total vaccum

Please also correct this:

Quote:
Latency is the delay between requesting data and the receipt of a response, or in the case of one-way communication, between the actual moment of a signal's broadcast and the time received at its destination. Compared to ground-based communication, all geostationary satellite communications experience high latency due to the signal having to travel to an altitude of 35,786 km (22,236 mi) above sea level (from the equator) out into space to a satellite in geostationary orbit and back to Earth again. This latency problem with satellite communications can be attenuated with TCP acceleration features that shorten the round trip time (RTT) per packet by splitting the feedback loop between the sender and the receiver. Such acceleration features are present in recent technology developments embedded in new satellite Internet services like Tooway[1].
The signal delay can be as much as 500 milliseconds to 900 milliseconds (one way), which makes this service unusable for applications requiring real-time user input, such as online games or remote surgery. This delay can be irritating with interactive applications, such as VoIP, videoconferencing, or other person to person communication.
Taken from here: Satellite Internet access - Wikipedia, the free encyclopedia

My misinformation came from...well...others misinformation. I just knew about the problem through talking to experts (like...you...) and couldn't recall exact numbers.

In addition, 240 ms is still terrible by the terrestrial based internet standard everyone is comparing it to, so my basic point is unchanged.
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Old 26-08-2009, 20:20   #49
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Quote:
Originally Posted by Event_Horizon View Post
You are probably right, after all I'm a mechanical engineer and thus...don't work on satellite networking. First off let me adjust your 3rd point.

3) Radio waves move at the speed of light...but only a complete and total vaccum

Please also correct this:



Take from here: Satellite Internet access - Wikipedia, the free encyclopedia

In addition, 240 ms is still terrible by the terrestrial based internet standard everyone is comparing it to, so my basic point is unchanged.

Event_Horiszon,

Please understand that I am truly not implying your opinion isn't valid.....
By that I mean, I understand that you think satellite based internet access is slow.....

I assume that is your "basic point".....
But, compared to what????

PLEASE understand that your opinion is valid.....satellite internet is slower than most terrestrial systems.....
And, I agree.......

But, you worded your post as fact.....not opinion.....
That's why I was so blunt and direct.....
And, while we are all entitled to our opinions, presenting them as fact just seems wrong.....


Secondly, I'm the first to admit that I'm NOT an IT guy...far from it...
My major was physics, with a minor in management eng.......(never worked as a phyisist though, as I started my own business....)
So, I'll certainly concede that what I know about IP latency I could write on my thumbnail with a sharpie.....
But, my points were regarding your contentions about the time it takes for a signal to make its round-trip to/from a satellite......
So, I just presented the facts....
The facts are as I presented them......no matter what crap is posted on wiki.....


Thirdly, as you should know, outer space is as close to an absolute vacuum as you can get......
And, furthermore, electricity (such as all those "1's" and "0's") travels SLOWER in copper wire (such as that used in electronic devices....like modems, computers, etc.....not to mention the wiring that IP data flows thru on DSL connections, etc.) than it does through the atmosphere, which as you pointed out is slower than would it a vacuum......

Anyone that posts
Quote:
Radio waves just cant complete with electricity and light in terms of speed over sheer distance.
is either assuming everyone is an idiot or thinks it's April Fool's Day......
Come on man.....
Get serious.......after majoring in physics and making my living in satellite communications for 25+ years, do you really think I need you to tell me how electrmagnetic waves travel?????


Fourthly, wikipedia?????
Really????
I mean I know many laypersons post / write for wiki.....and I know wiki has a big following....but for those in the know (such as ME's, etc.) it's sort of a joke.....
Come to think of, I assume you're just poking fun at me, with this wiki reference......Actually, I suspect that you've figured out who I am??? and hope to get me going on and on about sat. comms.....sorry, not tonight....

If had the time, and desire to dig out some reference material (books), I suppose I could go on and on with the real facts about these matters, rather than wikipedia crap.....
But, there's no need for that.....
Since all you need do is read what I wrote:
".....Transmission latency...." is what I wrote.....
I was not commenting on specific IP pecularities reducing the effectiveness of geostationary satellites when used for live internet gaming......

Not to mention that the discussion I referenced was about Iridium Open Port, which uses Low Earth Orbiting satellites.....so all the wiki crap would not apply, even if their words were factual and accurate, which they are not....

Event_Horizon, I can only assume you're having a poke of fun here....
And, hey, I've got a sense of humor.....so no big deal.....
But, just for clarification, live internet gaming has troubles with many ISP's and some in-house systems.....and I'll go out on a limb here and say that I doubt anyone sailing to far flung places and across oceans, has any interest on live internet gaming......

And, for further clarification, anyone else reading this should not take the wiki info as gospel.....oh, boy...not even close.....

Gotta go....
Take care...

John
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Old 26-08-2009, 21:50   #50
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Heave-to there sailer. I'm not poking fun at you. As I said before, you are the expert and I'm not trying to argue with you. The suggestion to edit the wiki page was a serious one. Not to get too off topic, but in my defence wikipedia is professionally moderated and corrected. Of course I don't to reference it in my thesis...but it usually doesn't dissapoint (get things wrong). If you have a contribution, I say you make it so I dont attempt to peddle misinformation.

Secondly, I've only had experience with satellite stuff in designing automated systems for human remote piloting purposes. Sound oxymoronic? Well it turns out some people thought satellite latency was so bad that they got a bunch of us to try and come up with some ways to compensate for control gaps and short information blackout in highly sensitive dynamic systems (think helicopter).

Lastly...

Quote:
Originally Posted by ka4wja
......Actually, I suspect that you've figured out who I am???
This line almost tempted me to do a google search for all satellite related company CEO types named "John". Alas I'll let you keep that mysterious internet mistique (for now! dun dun duuuun )

I conceed all points relevent to your arguments with the exception of my original conclusion. People can now officially stop stating that their satellite connections are slow because it is to be expected when compared with landlubber expectations (FIOS, DSL, Cable).

Fiasco over with this? We will see.....
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Old 26-08-2009, 23:02   #51
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Hey, guys, cool down or slow down - this is a cruising forum - sailboats and powerboats. None of us could possibly need megabite per second data streams (except when posting on this forum) for our purposes of planning and executing our sailing passages. What is relevant to our purposes is cost of a usable communications link to get our needed data. At $6K plus more than a dollar a minute satellite is way too expensive. We can get our needs from Winlink for free; Sailmail, more economically; or WiFi in harbor for free or on average $50/month.
- - Since it is a given that most cruisers spend 90% of their time in harbor and only 10% underway (between harbors). Satellite is an extreme luxury item.
- - Even aircards using cell systems are disappearing as free WiFi or low cost WiFi pushes them out of the market.
- - It was not clear in the originating post of this thread what the question was. I assumed from the language >>"INTERNET OS (operating system)"<< the question was about the new "Cloud Computing". Never got an answer on that. But then maybe it was asking about cruisers who operate business via the internet. What do they do when at sea? Never got an answer on that one either?
- - Either way the information you have presented is fabulous and for that I, for one, am grateful for your taking the time to give us the "background" on internet access via satellite. Thank you.
- - My point as stated is that Satellite for cruisers is in the extreme luxury category until it can match ground based internet systems. I have seen small speed boats with cubby cabins and a satellite dome so there is a market there just not for penny pinching cruisers like me and others.
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Old 27-08-2009, 05:26   #52
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I'll add another layer of complication here. All of you techies can fight about latency and what the meaning of the word "is" is...oops, I mean what the meaning of the word "slow" is. When the politicians get involved trivial things like the laws of physics do not apply. In the Bahamas, where I live part time, in order to use a satelite based Internet system like Hughes Net, you need a special government license (I think the current rate is $300 per year) because you are operating a transmitter. I don't know what the laws are in other places, but I'd hate to spend big bucks on a satelite internet connection and have to worry about licensing every time I changed jurisdictions.

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Old 27-08-2009, 08:06   #53
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The fact is that satellite internet, as sold by land-based providers like DirecTV, isn't as fast as cable or wireless but is a hell of alot faster than a modem.

If you go to many Carribean islands, you will see a big satellite dish on top of the highest hill. I assume that's where the local Internet cafe is getting its connection, along with the cell phone and CATV subscribers who live there.

If you can stream full color TV at 30+ frames per second via satellite, then the technology must exist to provide fast Internet service.

As I said, it's coming, we just don't know when.
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Old 27-08-2009, 10:10   #54
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Internet at Sea

Hey guys, no worries here....

Sorry, if I jumped on my soapbox to quickly.....

As for my situation on board....I do mostly long range voyaging......and do NOT have internet on board....heck I don't even have e-mail at sea....
No sailmail, No winlink, No Iridium, etc....
I DO love all of those, but when I'm off on some long passage, I have no need (and no desire) for them....

When in port, I'll use internet cafes, etc. for my meger internet / e-mail needs....
(Although, I'm thinking I may actually take my laptop with me next time I head for Europe....)
I told you I wasn't much of an IT guy....

Fair winds...

John
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Old 27-08-2009, 11:23   #55
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Inmarsat broadband, if you can afford it.

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