Can you make your own wifi router or dedicated data link for the internet? - Page 1
Forum section: electronics / rf-microwave

author: Beamin
author_rank: Super Contributor
timestamp: March 12, 2018, 11:38:06 am
content: Would it be possible to use your ham lic or ISM band etc, to set up a long range data link to access your internet from home?Not super fast data links but take an internet connection and pipe it into something like a hackRF and connect up a directional antenna and then have another set up on a portable computer. Application would be having a cabin on your property and wanting it to get internet without using cellular data a mile or more away.

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: March 12, 2018, 11:57:38 am
content: There are actually systems available for this. I know Ubiquity makes a lot of these systems for "long range" wifi. Either by using big parabolic dishes for 2.4, and I think they also have some systems that use a higher frequency to beam the data and then downconvert it back at the other end. I don't know about price, but remember some of them being suprisingly affordable (or at least I thought they were)

author: Bratster
author_rank: Frequent Contributor
timestamp: March 12, 2018, 04:18:56 pm
content: Look at a Ubiquiti rocket M5 radio, rocket dish antennas.There are some larger sizes and some smaller sizes as well depending on how long the distance is.There are also a bunch more models. Some I think can even get you a 1 gigabit Link in both directions, or at least close to it.We use the rocket m5 at work to get internet up to remote transmitter sites. 100 megabit link easy.Sent from my Nexus 6 using Tapatalk

author: David Hess
author_rank: Super Contributor
timestamp: March 12, 2018, 04:23:23 pm
content: You do not have your country marked but at least in the US, using an armature radio license for this is not feasible because of the content and even if it was, there are better solutions like the Ubiquiti radios that TheUnnamedNewbie mentioned which are exactly what you need to do this.Configure a pair of Ubiquiti Litebeam radios to bridge (easy) or route (more difficult) between networks and you are good to go.

author: ahbushnell
author_rank: Frequent Contributor
timestamp: March 12, 2018, 10:48:04 pm
content: Quote from: Beamin on March 12, 2018, 11:38:06 amHow long a range? You can buy Wifi antennas that have hi gain. that would be a simple approach.

author: tautech
author_rank: Super Contributor
timestamp: March 12, 2018, 11:03:15 pm
content: Quote from: TheUnnamedNewbie on March 12, 2018, 11:57:38 amExactly !You just need to power them POE and roughly point them at one another for 5km range.https://www.streakwave.com/itemdesc.asp?ic=LocoM2-USThen connect the remote unit to a WiFi access point or a remote switch.Hey presto, long range home-group.

author: Beamin
author_rank: Super Contributor
timestamp: March 14, 2018, 12:00:08 pm
content: Hak five explained how you do this legally. I guess the point of the video was that you would not detune the radio after setting it up like they did to get long range. The way they did it basically detuned the radio back down to what it was out of the box but I'm guessing you were supposed to read between the lines. Pinneapple or some inexpensive device. That show is so frustrating because they don't post the second half of the videos then you go to their site and can't find it because they took it down. Like having sex without getting off at the end. Why would you do that to yourself? Exercise?

author: Lord of nothing
author_rank: Super Contributor
timestamp: March 19, 2018, 06:45:52 pm
content: SO where are you from?To make it legally it realy depend where you life. For example here in Europe what I know the max. Output power on 433mhz Band is 0,5W and the duty circle is 10% when I remember right. The max Bandwith is 20khz I think?Sure depend on your Country who not via CB Radio?With Packet Radio you can Transmitt 24/7 legally.

author: Beamin
author_rank: Super Contributor
timestamp: March 22, 2018, 07:02:54 am
content: Quote from: Lord of nothing on March 19, 2018, 06:45:52 pmIn the US we have some some "junk" bands like the 27mhz/11 meter or 49 mhz thats dead since cordless phone abandoned them in the higher and higher ghz wars. Marketing thought right that people would think more MHz is better when in reallity the 900 mhz cordless phone is king. The CB band is abused so bad that you could use a few channels of continous 100 watt power and as long as you stay within the frequency minding your harmonics no one would care. Who would complain? Truckers using 100 watt over modulated radios complaining that they couldn't use racial and homophobic language at people? The CB band is just embarasing to listen to becase they tal in this weird accent and repeat words; it just sounds so stupid. In the 90's as a kid my friends all had one and we would make fun of the grown adults on CB. The people were usually trailer trash and pedophiles I remember alot of guys used to try and get my phone number or want to meet in person. But now it's much worse. I lived on a hill had a 2 huge dipoles and would tweet the bias in the CB and modulation. Of course the CB would stop transmitting in a few months but at 40$ just buy a new one.

author: KD4PBS
author_rank: Contributor
timestamp: March 22, 2018, 08:51:09 pm
content: As others wrote, legally speaking, not likely.Remember that as an amateur radio operator, you're restricted to a few rules that would not be easy to guarantee:1) Can't run any kind of encryption. So basically, all your everything that you do over this connection will not be able to be encrypted, including your login passwords, etc. So, there'd be no using a SSL or an HTTPS:// web browsing session.2) Can't use it for business at all. Even purchasing something on Amazon over this link (if you were able to log on without encryption) would be a touchy "gray" area.3) Can't use it to browse anything that would be illegal to transmit over amateur radio, such as profanity, and that stuff that people say is the #1 reason people use the internets... pronography.

author: Lord of nothing
author_rank: Super Contributor
timestamp: March 22, 2018, 09:35:29 pm
content: So CB or PMR446

author: janoc
author_rank: Super Contributor
timestamp: March 22, 2018, 10:17:40 pm
content: Quote from: Beamin on March 12, 2018, 11:38:06 amTechnically this isn't a problem, however it could be iffy legally.You certainly can do that but usually not on a HAM license. HAM licenses explicitly prohibit commercial traffic, so unless you are planning a HAM only network (such as HAMNet:http://www.broadband-hamnet.org/), you wouldn't be able to operate such setup for Internet access on a HAM license.Doing it with ISM hw may or may not be possible - the ISM general licenses are usually tied to the hw including specifying allowed antennas and total EIRP which must not be exceeded. So doing something like adding a high gain antenna to your WiFi router (or something else) to extend the range may be very illegal. Check the applicable rules in your country before you engage in something like this otherwise you could end up with a really nasty fine.However, what may well be an option is an optical link. Either using a laser or even high power LEDs + some lenses. A mile or two is perfectly doable and typically these things are not regulated/licensed (apart from laser safety regulations that may be applicable). The only problem is that you need a straight unobstructed visibility between the two points you want to connect - but that would very much be the case for the ISM band frequencies at such distance too. In the worst case a simple repeater (= mirror?) to bend the link around an obstruction could help too.If you decide to go for this, there are commercial laser-based devices but you can also build it yourself - e.g. the Ronja:http://ronja.twibright.com/(10MBit 1400m airlink w/ LEDs ...)

author: Beamin
author_rank: Super Contributor
timestamp: March 23, 2018, 06:26:14 am
content: Quote from: KD4PBS on March 22, 2018, 08:51:09 pmyea but in reality no one is going to know or care. I don't think some one would go through the effort even if they could to prove some data sent over the air had the word fuck on a web page.

author: KD4PBS
author_rank: Contributor
timestamp: March 23, 2018, 04:21:56 pm
content: Quote from: Beamin on March 23, 2018, 06:26:14 amSadly, that's the kind of thinking that many new amateur radio operators have. Thankfully most of them think that 2 meters is the only band that exists, so they rarely cause any real problems for the majority of us who stay away from that band after getting sick of hearing people say things like, "How many bars am I puttin' on your meter?" and "Well, my ess dubya arrs are better now that I cut a few inches out of mah co-axal."Those buffoons find out very quickly what reality is when they start operating like this in an area where people do still care. I guess there simply are lots of people out there who think that laws weren't made for them. I, for one, enjoy watching their reaction when factual, truthful reality knocks their false reality in the mud.

author: janoc
author_rank: Super Contributor
timestamp: March 24, 2018, 04:49:04 pm
content: Quote from: Beamin on March 23, 2018, 06:26:14 amYou are pretty badly mistaken here. People will call you out on HAM bands for much smaller transgressions than this. And some folks really do love sending complaints to FCC/whatever-your-local-authority-is-called.It isn't about the word "fuck" or something else on a webpage but you will be breaking the restrictions on:1) Carrying commercial (= public internet) traffic over HAM links - explicitly illegal for amateur radio service. This alone would get you busted and is trivial to prove.2) Allowing unlicensed operators to operate HAM gear without supervision is not legal - depending on where you live, this rule is sometimes applied to a remote machine (router/server/whatever) connecting through your HAM link and thus "operating" your transmitter. This is often a grey area and very much depends on how hard the local regulator decides to throw the book at you.E.g. in Slovenia they were using their high speed packet radio network to connect to the Internet but it wasn't legal to build something like that in Slovakia where I am from because of this rule, even back in the day when the Slovak internet was strictly non-commercial, academic network (so wouldn't break the point 1)3) Encryption/scramblers/etc are not legal neitherSo if you are planning on breaking the law, don't do it on HAM frequencies - unlike the other bands (ISM, CB, PMR ...) where you are going to get caught only if you interfere with something that someone does care about or it is a government service (police, airports, etc.), on HAM frequencies many people are actually listening and youwillget your backside busted sooner or later.The fines are pretty juicy and even if you don't get fined, getting a surprise visit and having to show all your papers, logbook, have your gear inspected and measured with the government techs looking for the smallest problem to fine you on is not a fun experience. I know one HAM who had to go through this several times - because of an asshole neighbor not liking his antennas sending bogus complaints about interference to the regulator's office.Not to mention that this is a prettyattitude, especially if you have or are planing to get a HAM license.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 24, 2018, 06:40:25 pm
content: Isn't the definition of "commercial" involve transfer of money or other item of value?A workaround to the transmitter being controlled by an unlicensed entity is to not transmit until a licensed operator sends a "reply with data" command, so that the base station is acting as a transponder. Might also be possible to have it transmit based on a timer so it acts as a beacon.Encryption is not allowed, but cryptographic signing might be. It does not obscure the content but does allow verification that it is an authentic message. It would not be very helpful for clandestine uses but would make it far more difficult for a hacker to impersonate a legitimate user.

author: janoc
author_rank: Super Contributor
timestamp: March 24, 2018, 10:00:57 pm
content: Quote from: NiHaoMike on March 24, 2018, 06:40:25 pmNo. The exact definition is in the ITU documents but for the purpose of the debate it pretty much means "anything else but HAM traffic", i.e. communication with other licensed amateur radio operators. Heck, in most countries you are not even allowed to transmit messages on behalf of a third party, except if they are a HAM or in very limited set of circumstances such as emergencies or disasters.The content of what is allowed to be transmitted is fairly strictly regulated, typically (quoting UK rules because they are in English):Quote(clauses 1(2) & 1(3) are about emergency comms)Quote from: NiHaoMike on March 24, 2018, 06:40:25 pmThat workaround doesn't work because the by the time the licensed operator replies your typical TCP connection would have timed out already. Also your regulator may not look at this kind of blatant attempt to skirt the rules lightly. But again, this may or may not be an issue, it depends on jurisdiction.Another thing is that a HAM radio station must by default be manned by a licensed operator, in most countries you aren't allowed to setup automated stations (repeaters, packet radio nodes, APRS trackers on unmanned vehicles, whatever) without a special permit and obtaining a call sign for them. (There are exceptions - e.g. UK seems to allow this for personal use only but not for the use by other HAMs - that has to be licensed separately)Quote from: NiHaoMike on March 24, 2018, 06:40:25 pmThat completely misses the point. The issue with crypto is that you wouldn't be able to use any service that runs over an encrypted connection (https for ex ...) or to hide your personal data from anyone who is in range and has a receiver. Those are far bigger issues when transmitting data over radio than someone trying to inject a bogus packet.If you want to see what how a typical version of rules covering HAM radio looks like, here is the UK one:https://www.ofcom.org.uk/__data/assets/pdf_file/0027/62991/amateur-terms.pdf(UK for no particular reason except that it is in English and is a fairly typical EU-style reg.)The US rules are here:http://www.arrl.org/files/file/Regulatory/March%208,%202018.pdf(US has a funky clause there prohibiting transmission of content that could be transmitted by other radio services - internet access would fall square under that. The idea is to not waste precious HAM bands on mundane things better served by other existing services already).I suggest that anyone who thinks they have a "clever workaround" how to bend the rules and/or thinks it is OK to break them actually get familiar with them first.HAM radio is really not meant to be used for things Beamin wants to do. That's straight in the domain of commercial hardware like microwave links operating either in the ISM bands or on dedicated (and licensed) frequencies.73, Jan OM2ATC

author: Beamin
author_rank: Super Contributor
timestamp: March 24, 2018, 11:20:12 pm
content: My rule of thumb is if no one hears it your good. Use very directional antennas and cut down the power as low as you can.But one time I did have the idea to give myself personal long range wifi when I lived on the roof of a building in the city. Go to your favorite restaurant and look you are on your home network!

author: tautech
author_rank: Super Contributor
timestamp: March 24, 2018, 11:25:13 pm
content: Quote from: Beamin on March 24, 2018, 11:20:12 pmYou forget the risk of interfering with another's legitimate transmissions and that why we have dedicated bands for the many types of communication.Go down this road of using another band NOT reserved for your intended use at your peril !

author: Mr. Scram
author_rank: Super Contributor
timestamp: March 24, 2018, 11:52:23 pm
content: Quote from: KD4PBS on March 22, 2018, 08:51:09 pmConsidering how the internet is moving towards SSL, not having encryption isn’t possible. Even securing your connection with a password should be considered illegal. Not being allowed encryption means modern internet goes right out of the window. It’s not viable.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 25, 2018, 07:06:54 am
content: Quote from: Mr. Scram on March 24, 2018, 11:52:23 pmYou can always run a browser on the base station and then do everything in cleartext over the radio - e.g. telnet into a Raspberry Pi running Lynx. You just lose the connection being private. And signing is not encryption - others can still read the information and they can use the public key to verify it really was you who sent it. I don't see why anyone would be against the idea of signing since a hacker impersonating legitimate users really doesn't do anyone else any favors. So while anyone would be able to see what you're doing, if you use a good signing algorithm, it would be basically impossible for a hacker to interfere with the connection in ways other than a DoS attack.

author: ogden
author_rank: Super Contributor
timestamp: March 25, 2018, 11:44:20 am
content: Quote from: Bratster on March 12, 2018, 04:18:56 pmOther option is Mikrotik LHG 5.Obviously forget that you are HAM, use legal in your area ISM frequency.

author: janoc
author_rank: Super Contributor
timestamp: March 25, 2018, 02:20:54 pm
content: Quote from: NiHaoMike on March 25, 2018, 07:06:54 amNihao, sorry, but that's utter BS and you are making an exemplary strawman argument with the signing issue (which was never even a topic of discussion). Your "solutions" are both completely impractical (how would you control the browser?) and still completely illegal because regardless of the encryption issue, HAMs aren't allowed to transmit this kind of traffic. Please, do read the rules I have posted before you try to engage in some more "engineering exercise" trying to "solve" what is a legal and regulatory issue and not an engineering problem!A lot of people who though they were being clever (and everyone else stupid!) wound up on the wrong side of the law because of this.

author: janoc
author_rank: Super Contributor
timestamp: March 25, 2018, 02:27:22 pm
content: Quote from: Beamin on March 24, 2018, 11:20:12 pmYou are forgetting that even directional antenna is not 100% directional, they emit in a cone which spreads out with a distance. Anyone within that cone can hear you. And the signal doesn't stop propagating at the intended destination neither. So you may think no one is hearing you but you may be causing interference e.g. on the air band at the airport a mile or two downrange from your installation. Or a cell phone tower nearby, depending on the frequency and bandwidth/modulation type you decide to use/abuse.Also no one hearing you doesn't mean nobody ever notices your antennas, for example. A microwave dish or a yagi have to be in the open to work. And in that case it is a trivial matter to cross-check with the database of licensed operators (both HAM and non-HAM, in many countries these things are a matter of public record and include addresses of the people/companies holding the licenses) and see whether the installation is legit or not. And potentially call the inspectors.So what you are describing are sensible things to reduce interference but they are absolutely no guarantee you wouldn't get caught.If you really want to solve this problem (as opposed to just pointless trolling and stirring up "shit" in the forum), get either a commercial pair of radio modems or buy/build a laser link. Both are much simpler to deal with than trying to do it with HAM radio equipment which is not designed for this type of service. And both will also save you issues with breaking the law and getting fined/having equipment confiscated.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 26, 2018, 05:02:00 am
content: The signing is just a way to implement access control without encryption. You'll have a connection that's "secure" in the sense that it's difficult to spoof packets but not secure in that anyone can still read the data in cleartext.Of course, it's starting to sound way more sensible to just use ISM and not have to deal with the amateur radio restrictions. Lora can do very long distances with very little power, maybe a modified version operating just within legal limits can be a good option?

author: Berni
author_rank: Super Contributor
timestamp: March 26, 2018, 05:27:57 am
content: All you need is a pair of directional antennas and and a pair of regular routers. The directional antennas can even be built DIY out of some solid core wire and copper clad boards. A good directional antenna might have about a 30 degree field of view. With line of sight the setup can work over 10km no problem.Now if you really want to go far you can also buy routers with higher than usual TX power and use those on both sides of the link. Normal home routers are limited to 100mW of transmit power since that's the most that is allowed by the regulations in most parts of the world. But there are routers that are capable of much higher power and are just software limited down to comply with local regulations. For example MikroTik makes high quality network gear that is still pretty cheap. Some of there wifi routers have 1W of transmit power and you can convince it to use that all of that power by simply selecting a country that allows it under regulation (like Taiwan)However doing this is technically illegal and putting that sort of power into a highly directional antenna makes a very intense radio field in front of it. So such an antenna should be placed outside, high up and pointing away from any other buildings or equipment. Tho if you are able to get line of sight with directional antennas i highly doubt you would need anywhere near that much power anyway.

author: janoc
author_rank: Super Contributor
timestamp: March 26, 2018, 12:06:26 pm
content: Quote from: NiHaoMike on March 26, 2018, 05:02:00 amaThe problem of this is, again, that you are solving a small part of the issue and ignoring the elephant in the room. Anyone building a wireless link to the Internet will just run encryption on it wholesale or run a VPN. There is no point in spoofing a connection (e.g. to hack your e-mail account) when you are giving me the login and password in cleartext already (because the crypto is verboten on a HAM radio link).There are situations where not running all out crypto but signing packets may be useful (e.g. remote control of something) but that is not the situation here. And even in those situations it is rarely needed to go all out with crypto signing, typically something like nonces, sequence numbers chosen from an OTP pad or something similar will do the same job without the expense of the crypto.Quote from: NiHaoMike on March 26, 2018, 05:02:00 amKeep in mind thatyou are not allowed to modifyany ISM equipment. That includes antennas and output power. Only HAMs are allowed to build and modify their equipment when operated under the HAM license restrictions. This actually a very unique exception, no other service (as defined by ITU) has this ability. Once you modify any ISM gear, its certification and "general license" for operation (for the lack of better term) are void and you are not allowed to operate such equipment.That you don't need a license for e.g. your wifi doesn't mean the operation is unlicensed - it is the gear that has the license to operate it associated with it and guaranteed by the manufacturer - as long as nobody has tinkered with it.So ISM equipment may work as long as you can use itunmodified, with the stock (or specifically manufacturer approved) antennas.Now legal issues aside, as long as you don't go nuts with output power and/or cause interference wiping out wifi, garage openers and what not in the quarter, you aren't very likely to get you backside busted on ISM bands for having a better antenna. On the other hand, given that there is so much going on those bands, you are pretty much guaranteed to be stepping on someone else's toes and someone is going to notice your traffic sooner or later.Some people were also mentioning LoRA - guys, LoRA is meant for small sensors and such, with its ~5kbps speed you wouldn't want to connect to the internet over it ...

author: ogden
author_rank: Super Contributor
timestamp: March 26, 2018, 12:23:07 pm
content: Quote from: janoc on March 26, 2018, 12:06:26 pmExactly. Why would anyone shall consider to modify/build anything if there isUbiquiti outdoor point-point radio terminal+antenna for MSRP 49$! Do you bake bread and milk a cow as well? - Save your time and build something that is not so easily available

author: janoc
author_rank: Super Contributor
timestamp: March 26, 2018, 12:35:53 pm
content: Quote from: ogden on March 26, 2018, 12:23:07 pmI don't have a cow but baking own bread is something a lot of people do. It is just better than store boughtOTOH, on what band does that Ubiquiti gear actually operate on? Because it may be cheap to buy but if you have to pay a few hundred bucks an annual license for the spectrum used it could get rather expensive ...EDIT: It seems to work in the 5GHz ISM band, so the license fees shouldn't be an issue.

author: ogden
author_rank: Super Contributor
timestamp: March 26, 2018, 01:01:20 pm
content: Quote from: janoc on March 26, 2018, 12:35:53 pmDepends on store. I bet you can't beat bread I am getting in my preferred bakery. The same way I did not offer to buy 18$ APG721 "generic point-pointsupermarket breadAP" but something that is worth to consider. Indeed there are better options than mentioned 49$ Ubiquiti AP like Mikrotik products, but this one is lowest cost which I dare to suggest.

author: janoc
author_rank: Super Contributor
timestamp: March 26, 2018, 02:20:29 pm
content: Quote from: ogden on March 26, 2018, 01:01:20 pmLet's not get into another tangent on bread baking, LOLBut the Ubiquiti stuff is supposedly decent, it is quite often being repurposed for HAM radio uses too. Certainly seems like the cheapest and least problematic (engineering and legally-vise) option for what Beamin was looking for.

author: KD4PBS
author_rank: Contributor
timestamp: March 26, 2018, 03:22:54 pm
content: I think this thread certainly explains the depth of ridiculousness that the internets is capable of.The question was, "Would it be possible to use your ham lic or ISM band etc, to set up a long range data link to access your internet from home?"The answer was given, along with the explanations of fact for the answer.That answer was not accepted as fact - odd, considering that the facts are conclusive, established with precedence, and on-point to answering the question.What's to argue? You want to do this? Fine. People break laws every day. Some even get by with it. For a while.But to argue that something which is illegal to do is okay, orshouldbe okay to do merely because you think itshouldis okay to do is stretching it quite a bunch.Do it in my neighborhood, and you'll find out quickly how much of an inconvenience for you it can be to break laws such as this, and I'm not the only one in the world who watches for things like this going on. You want to break the laws? Go for it, chief. Just don't try to tell me that you are in the right for doing so.

author: tautech
author_rank: Super Contributor
timestamp: March 26, 2018, 06:40:23 pm
content: Quote from: janoc on March 26, 2018, 12:35:53 pmAny of the legal bands, Period.Have a look at their international website and they have a multitude of products available to suit most needs.My ISP uses heaps of their gear, they have a 5GHz LiteBeam dish for ouroutsideworld connection and relay to other locations for them with a 450x90mm 120o5GHZ LiteBeam sector panel and added a further 2.4GHz NanoStation that extends our connection to my sons dwelling a few hundred meters away.https://www.ubnt.com/airmax/nanostationm/I linked a seller of this Nanostation earlier and you need a pair of them to enable LOS range to 15km.Plenty far enough for the OP's needs.

author: janoc
author_rank: Super Contributor
timestamp: March 27, 2018, 11:25:29 am
content: Quote from: tautech on March 26, 2018, 06:40:23 pmCareful with a blanket statement like that. There are bands where you can operate some gear without passing any exams and such (like HAMs need to do) but you actually do have to obtain license/pay spectrum fees - e.g. GMRS walkie-talkies in the US (where Beamin seems to be located, based on his previous comments). It is only a formality but you still have to do the paperwork or you are risking a fine.On the other hand, it shouldn't be too difficult to choose a suitable kit where you don't have to do this, there is plenty of it available.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 28, 2018, 12:45:44 am
content: Quote from: janoc on March 26, 2018, 12:06:26 pmWhy send the login over the connection when you can just store it on the base station? Then just send a command to the base station to tell it to login using the secrets stored in it. Everyone will be able to see that you made a login, but not what the login details are. (Or for that matter, have the base station log in automatically) Or there are some uses - think just quickly checking Wikipedia or similar - that doesn't need a login at all.QuoteI was thinking more along the lines of finding an off the shelf module and just using it as part of the system. E.g. connect a 900MHz video transmitter (picking one that's rated to the legal limit with no mods) to a cheap FPGA board through a DAC, then on the receive side, decode it with some sort of SDR. (RTL-SDR might work but can only receive a small part of the 900MHz band at any given time.) Note that you can modify the receive side all you want as long as it doesn't start emitting unacceptable levels of interference as a result.Those directional Wifi range extenders would work if they can make the distance, but it's nice to think about possible solutions for when those don't work.

author: ogden
author_rank: Super Contributor
timestamp: March 28, 2018, 02:23:49 am
content: Quote from: NiHaoMike on March 28, 2018, 12:45:44 amIn what dreamworld you are living? Do you have slightest idea how much DSP development is needed to achieve what you just describe? Why do stoopid people buy car? - All is needed some metal for car, rubber for tires and of course fuel to drive it.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 28, 2018, 05:52:28 am
content: Quote from: ogden on March 28, 2018, 02:23:49 amMy friend Tiffany Yep does just that and she definitely knows how hard it can be. At the same time, you'll be surprised just how good the SDR community is. Just look at all digital modulations developed for amateur radio that strive to work where others don't.

author: janoc
author_rank: Super Contributor
timestamp: March 28, 2018, 10:44:18 am
content: NiHaoMike, sorry, butSeriously dude, get real and stop fantasizing about stuff you have obviously never tried yourself.

author: BravoV
author_rank: Super Contributor
timestamp: March 28, 2018, 11:12:20 am
content: Quote from: janoc on March 28, 2018, 10:44:18 amHe has been doing that weird posts on behalf of that particular girl's name for almost a decade here in this forum.Hint : Try using advanced search in this forum, post made by him, with the search subject name of that girl, I guess you will drop your jaw.

author: ogden
author_rank: Super Contributor
timestamp: March 28, 2018, 12:22:28 pm
content: Quote from: NiHaoMike on March 28, 2018, 05:52:28 amMaybe she knows, but you apparently have no clue.I am curious which 900MHz video transmitters are good for application you mentioned. Name at least one. Also state TX power, frequency and bandwidth you offer to use that would be legal in US.QuoteOk. Surprise me. Please list those digital modulations developed by SDR community that strive to work where others don't.

author: janoc
author_rank: Super Contributor
timestamp: March 28, 2018, 01:29:46 pm
content: Quote from: BravoV on March 28, 2018, 11:12:20 amYeah, just realized that I have seen this "My friend Tiffany Yep ..." before - and pretty much always in a similar, nonsense context. Nice troll ... Some people really have too much time on their hands.

author: KD4PBS
author_rank: Contributor
timestamp: March 28, 2018, 02:24:26 pm
content: You mean, y'all can't get a 35 dB or greater SNR and less than a dB MER using a drastically non-linear FM video modulator/demodulator setup modified to cram 45Mbps into it's bandwidth?Obviously y'all aren't trying hard enough.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 29, 2018, 03:26:27 am
content: Quote from: ogden on March 28, 2018, 12:22:28 pmWSPR, PSK31, and PSK63 just to name a few. Granted, they're for a completely different sort of application, but it is surprising what amateur radio operators come up with. Also interesting to read about what hobbyists are coming up with for digital FPV - a use case that values low latency and rapid adaptation to changing conditions.Quote from: KD4PBS on March 28, 2018, 02:24:26 pmWith 26MHz of bandwidth available on that band (in the US) and 802.11n fitting 72Mbps into 20MHz of bandwidth, it's definitely possible. Given the same transmit power and antenna gain, it will likely go quite a bit farther than 2.4GHz largely because the 900MHz band is far less used. There's almost nothing in the way of 900MHz Wifi, which is both a plus and a minus. Even with all that, 45Mbps at a range of a mile is asking for a lot.Now I wonder how much could be gained running multiple 900MHz transmitters in parallel, making sure the frequencies do not overlap.

author: ogden
author_rank: Super Contributor
timestamp: March 29, 2018, 12:25:35 pm
content: Quote from: NiHaoMike on March 29, 2018, 03:26:27 amI do not see any newly developed digitalmodulationshere. WSPR uses FSK which dates back in 1958 (BELL 101 modem). PSK31 and PSK63 uses guess what - PSK which again is nothing new.None of saidtransmission modeswere developed by SDR community as well. WSPR was developed by Joe Taylor (K1JT), PSK31 - by Peter Martinez (G3PLX).QuoteSeriously? Idea of using narrow bandwidth to get better SNR isbasics of signal transmission. Only thing we can be surprised here - how slow amateur data transmissions actually are: WSPR needs 110 seconds to transmit 50 bits, PSK31 bit rate: 31 bits per second, PSK63 accordingly 63bps.

author: ogden
author_rank: Super Contributor
timestamp: March 29, 2018, 12:45:09 pm
content: Quote from: NiHaoMike on March 29, 2018, 03:26:27 amWell, what you say is simply illegal.FCC § 15.247:For frequency hopping systems operating in the 902–928 MHz band: if the 20 dB bandwidth of the hopping channel is less than 250 kHz, the system shall use at least 50 hopping frequencies and the average time of occupancy on any frequency shall not be greater than 0.4 seconds within a 20 second period; if the 20 dB bandwidth of the hopping channel is 250 kHz or greater, the system shall use at least 25 hopping frequencies and the average time of occupancy on any frequency shall not be greater than 0.4 seconds within a 10 second period. The maximum allowed 20 dB bandwidth of the hopping channel is 500 kHz.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 29, 2018, 03:13:00 pm
content: There's a commercial product that claims to do up to 100Mbps on 900MHz:https://www.balticnetworks.com/ubiquiti-nanobridge-m9-900mhz-13dbi-dual-polarity-dish-bridge-solution.html

author: KD4PBS
author_rank: Contributor
timestamp: March 29, 2018, 03:22:00 pm
content: Ogden, that's part 15. We're talking part 97 rules here. In particular, §97.311 states that an amateur radio operator can use spread-spectrum communications to whatever extent he or she wishes, as long as it is allowed in that band. In essence, an amateur radio operator can experiment with very esoteric things, as long as it is constrained within the boundaries of what a ham radio operator is limited. And what kills it is not your part 15 citation, but several part 97 rules:§97.113 Prohibited transmissions(a) No amateur station shall transmit:(4)Music using a phone emission except as specifically provided elsewhere in this section; communications intended to facilitate a criminal act;messages encoded for the purpose of obscuring their meaning, except as otherwise provided herein;obscene or indecent words or language; or false or deceptive messages, signals or identification.(5)Communications, on a regular basis, which could reasonably be furnished alternatively through other radio services.§97.307(f) The following standards and limitations apply to transmissions on the frequencies specified in §97.305(c) of this part.(1) No angle-modulated emission may have a modulation index greater than 1 at the highest modulation frequency.(Most Wifi modulation schemes are used with MI's far in excess of 1)NiHaoMike,Please tell me you don't think that somehow one can derive a baseband or IF output from some wifi device, feed it into a "rabbit" FM video transmitter, and be able to demodulate that signal out of the "rabbit" video receiver back to a WiFi signal. You do know what differential phase and differential gain is, what linearity means, and why all of this matters with a Wifi signal, right?

author: ogden
author_rank: Super Contributor
timestamp: March 29, 2018, 05:38:56 pm
content: Quote from: NiHaoMike on March 29, 2018, 03:13:00 pmOh, you are right. That product may occupy nearly whole 900MHz ISM band (904 - 926 MHz) with continuous "spread spectrum" transmission, yet got FCC ID (thus approval) for 47 CFR 15.247. Did not know that.Quote from: KD4PBS on March 29, 2018, 03:22:00 pmYou alreadysaid thatHAM cannot use his license for such kind of transmissions. So what remains - part 15. Or did I miss something?

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 30, 2018, 12:39:07 am
content: I was actually surprised how cheap 900MHz network stuff is nowadays. Probably helps that there is a mass market for 900MHz broadband transceivers (LTE) in some parts of the world. Still needs some very custom software but the bulk of the work is already made into ASICs.So the only reason to build your own 900MHz network hardware is to avoid getting locked into a proprietary system. At which point it might be more interesting to find the most popular system used and reverse engineer it, if only to validate its security or lack of it. I wouldn't be surprised if many of those systems rely a lot on security through obscurity, but you can always layer VPN on top of it.

author: ogden
author_rank: Super Contributor
timestamp: March 30, 2018, 10:53:07 am
content: Quote from: NiHaoMike on March 30, 2018, 12:39:07 amThere is no reason for sane individual to build own 900MHz (or any other freq) network hardware apart from pure entertainment or research/learning purposes.

author: KD4PBS
author_rank: Contributor
timestamp: March 30, 2018, 01:07:19 pm
content: Quote from: ogden on March 29, 2018, 05:38:56 pmWait, what?I think both of us are now cornfuzed. I thought we were all still busy beating a dead horse, while thrown a twist in talking about the 900MHz band now instead of the 2.4GHz band or above.Incidentally, can anyone explain why many people always write, "HAM" and not, "ham"? Every time I see it capitalized, I think, "Hold And Modify" - a term dating back to the Commodore Amiga.

author: ogden
author_rank: Super Contributor
timestamp: March 30, 2018, 04:04:28 pm
content: Quote from: KD4PBS on March 30, 2018, 01:07:19 pmRight. Now I am confused as well. Anyways I agree to what you are saying regarding everything including dead horse. IMHO answer to subject is: yes indeed youcanmake anything you want, but not always it is worth it.BTW I am surprised that FCC is allowing 100% duty cycle "spread spectrum" (which I believe OFDM is not) radios in the 900MHz band. Where they plan to run those "IoT thingie" long range networks then? AFAIK SigFox in US uses same 900MHz band.QuoteI can tell only about myself - all the time I assumed that "ham" is some obscure abbreviation and shall be written capital letters. It is not? - lol then

author: KD4PBS
author_rank: Contributor
timestamp: April 12, 2018, 04:48:19 pm
content: Quote from: ogden on March 30, 2018, 04:04:28 pmHa! Nope. Not at all.Technically it should be "Amateur Radio".As for the moniker, "ham", it is definitivelynotan acronym. The true meaning is much more dubious though...https://en.wikipedia.org/wiki/Etymology_of_ham_radioWhat is very hilarious though is the occasional story of a group of PETA-type wankers who protested outside the gates of a "Hamfest" (swap meet catering mostly to amateur radio enthusiasts). I kid you not!