kelabar
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Post by kelabar on Aug 29, 2020 1:41:41 GMT 10
Alright, time to learn about technology (That screeching sound is my fingernails digging in as I am dragged reluctantly, kicking and screaming, into the 21st century ). Could someone provide a quick explanation of Wi-Fi and Bluetooth, please? I am particularly looking at how it can be applied to something like the Briar app for use if country-wide phone or internet services are disrupted or destroyed. But all info appreciated. What device features are needed, how do they communicate, ranges, specialised equipment, etc. Also how Wi-Fi and Bluetooth are used in normal times. TIA.
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shinester
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Post by shinester on Aug 29, 2020 4:40:19 GMT 10
Quick and simple - bluetooth is quite short ranged, used mostly for accessories such as keyboards headsets etc. It can be used for filesharing though it's limited in range. - wifi is more for use within a building/house. With the right directional antennas this can extend to great distances, though typically it's using omni-directional [all directions] antenna and isn't going much past a few houses up and down the street at best. Neither is particularly good at communication over distance, nor for security. Messages to my mind are also not 'immediate', messages take time to write and see. Good for news, not so good for security. A message board handles the first part if you're looking to inform a community. The Briar app at a glance [I've seen quite a few of these apps before] allows sharing of files/messages when another user is nearby. A few houses down the street in real world terms. You 'could' go further with a directional antenna and if you were willing to set up phones with proper antenna on them on high points you might get a neighborhood coverage. You 'need' to have a string of working phones from where you are to where you want to send the message. Your phone - neighbor 1 [2 houses down] - neighbor 2 [5 houses down] - neighbor 3 [7 houses down] - destination [10 houses away] I have some old phones from an american network [I'd have to look up details] that are set up to be able to work as a kind of digital radio, aka not immediately able to listen to. They have about 1-2km range and you can send text etc. They are useless as phones for here, though the radio network works. Proper radios are still better, simpler and no issues with legality. They're meant for worksites. I would have rather spent the money on proper radios looking back, though they are a secondary layer of communication for me. On radios, you have to stay on citizen frequencies to be legal in normal times. I had to tune my baofengs into the proper frequencies, though if someone wanted to use them outside of the correct frequencies it would be easy to do and only people looking would find them. Don't do the wrong thing here in normal times, such as interfere with other people's frequencies [its tightly regulated], very hefty fines if you're found. There's all sorts of channels for bus companies and so on. If you're looking to set up a bunch of people with cheap and easy to use radios, baofeng BF-888S's are about $20 each. 16 channels, which can be programmed to be anything you like. A simple dial for the channel [and it tells you the channel it goes to] with a push to talk makes it easy for people unfamilar with radios to use them. I've got other baofengs also. The BF-888s include an ability to do 'basic' scrambling of the voice to one another. Get the USB charger version and add a solar charger. These are fine for a few kms [1-5]. It's all line of sight, that is the clearer the path from both antennas the longer the range, so very impressive distances can be done with the right antennas in a fixed set up. In Austere times, they can use what's called a repeater on a hilltop which repeats your message on another channel and sends it to the other side of the hill. Repeaters are already in use with citizen band radio. I am suspect of them being powered in a SHTF situation. Here's my old link on the topic of solar radios. ausprep.com/thread/3164/solar-charging-radio-system
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blueshoes
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Post by blueshoes on Aug 29, 2020 11:09:16 GMT 10
Good comments shinester thank you I would also add, bluetooth is a 1 to 1 connection and is only really designed for one connection at a time (which might be why there were some hairy conflicts when the covidsafe app and glucose monitors both tried using BT at the same time on an iphone) Wifi is centred around an access point, and devices connected to the same access point can hear each other talking to it. +1 for "just use CB" shinester you mentioned baofengs, are they generally scratchy and crackly or just some handsets? I've heard mixed things about them
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tomatoes
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Post by tomatoes on Aug 29, 2020 12:35:18 GMT 10
Quick .... If you're looking to set up a bunch of people with cheap and easy to use radios, baofeng BF-888S's are about $20 each. 16 channels, which can be programmed to be anything you like. A simple dial for the channel [and it tells you the channel it goes to] with a push to talk makes it easy for people unfamilar with radios to use them. I've got other baofengs also. The BF-888s include an ability to do 'basic' scrambling of the voice to one another. Get the USB charger version and add a solar charger. These are fine for a few kms [1-5]. It's all line of sight, that is the clearer the path ... I know I’ve asked you to clarify this before years ago - are the BF-888S’s the ones you need a radio licence for, or the much shorter range ones that anyone can use?
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shinester
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Post by shinester on Aug 29, 2020 13:14:29 GMT 10
I know I’ve asked you to clarify this before years ago - are the BF-888S’s the ones you need a radio licence for, or the much shorter range ones that anyone can use? Lol, sorry for not responding sooner. Radio license... if you use Australian approved devices on CB channels then you don't need a license. This is what most people do. If they are not 'approved' and you use them only on CB channels, I'm not sure how anyone would know [or care], though that's up to you. If you don't program the correct channels in [Australian suppliers may or may not do this] then you may well be using frequencies you're not allowed to. It is easy to do with a computer and a cable. --- Baofeng's, look they're not the ultimate device by any means. They do work pretty well. Its like going to bunnings for a drill, you can get dewalt or you can get bunnings brand. They both drill holes, the dewalt won't let you down but costs extra. I went baofengs for budget and utility. I would rather have 10 neighbors with them and helping with security than 2 with a top notch brand. There's also many spares if need be. I do have better gear, though I can't turn away from pretty decent for $20! I've got better antennas that cost more. BF888s are entry level, though they are super easy to use and work well enough. I haven't found them to be especially crackly.
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tomatoes
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Post by tomatoes on Aug 29, 2020 13:59:25 GMT 10
So the bf888s’s can be set to the frequencies to use without a licence - like the 40 or 80 channel radios you buy from Dick Smith etc, or can be set to be used on the frequencies that you need a licence.
Have I got that right?
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shinester
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Post by shinester on Aug 29, 2020 23:25:29 GMT 10
Yep.
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kelabar
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Post by kelabar on Aug 30, 2020 9:37:12 GMT 10
Thanks for the info. Bluetooth uses frequencies in the 2GHz range. There are a number of Classes, 1-5, with range and power use decreasing for each class. Most phones use Class 2 Bluetooth which has a range of around 10m. This is a guide, it can be more or less depending on what is in the way. Class 1 devices have a range of 100m, it can be more, up to 1km if line-of-sight or no significant obstructions. Surprisingly low power usage. Even Class 1 only uses 100mW. Part of this is the transmission type which, if I understand correctly, is a series of bursts rather than continual transmission. Bluetooth can connect to up to 7 other Bluetooth devices but usually only one, I think for security reasons. There is a master/slave relationship. If I understand it correctly, the slave devices are permanently active looking for transmissions from the master device so using multiple slave devices would mean powering them continuously which may be problematic if generating your own power. Am I right in thinking wireless mice and keyboards use Bluetooth? Probably Class 3 or higher because of limited range? Yes, they are. And those people with the Bluetooth earpieces (Aargh, cyborg, kill it, kill it! ), the earpiece is running off the phone in their pocket I assume? Sound right?
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kelabar
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Post by kelabar on Aug 30, 2020 9:43:46 GMT 10
I have some old phones from an american network [I'd have to look up details] that are set up to be able to work as a kind of digital radio, aka not immediately able to listen to. They have about 1-2km range and you can send text etc. They are useless as phones for here, though the radio network works. I don't get this! What is a digital radio? And why can't you listen to it immediately? Explanation, please.
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shinester
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Post by shinester on Aug 30, 2020 22:31:04 GMT 10
Effectively radios are usually analog, like FM/AM radio. Digital commercial radio encodes the signal as data 10101010s and then is converted by the receiver. So much like that, they're digitally encode CB-style radios that were add ons to certain US and Mexican mobile phone systems. I'd have to get the units from the shed to give you further specifics, though I think they're only 1W so limited in range, I got almost 3kms on line of sight [flat] without obstacles, much much less in buildings. So think CB that's very unlikely to be understood as it's not a system used in this country. I would still rather use CB to be frank as it's easier to use.
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kelabar
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Post by kelabar on Aug 31, 2020 1:18:24 GMT 10
Got it, thanks.
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shinester
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Post by shinester on Aug 31, 2020 8:51:50 GMT 10
Yup.
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