Is LTE over powerlines possible? - Page 1
Forum section: electronics / general

author: Asavage9794
author_rank: Contributor
timestamp: May 21, 2016, 01:15:07 am
content: I have a idea a awesome idea for everyone in rule areas to have 300Mbps down and 75Mbps up (Theoretical speeds). LTE over Power Lines. How would that go is that possible, and how do i push my idea to bigger company's to test my idea?What do you guys think?? Is it a dumb idea? or smart idea?

author: XOIIO
author_rank: Super Contributor
timestamp: May 21, 2016, 01:19:16 am
content: Well first off, how did you get to these theoretical speeds?I mean theoretically you could get 100gigabit up and down.Anyhow, those wall plug adapters are usually crappy enough with a short distance, long distance would be way harder, plus you will need to get a bunch of equipment put in, it would probably just be more worthwhile to upgrade existing towers, as they are doing.

author: Monkeh
author_rank: Super Contributor
timestamp: May 21, 2016, 01:27:42 am
content: Not going to happen.It's hard enough to get anywhere near that bitrate out of a twisted pair phone cable for a few hundred metres, how do you think it's going to work over some random powerlines for kilometres?

author: amspire
author_rank: Super Contributor
timestamp: May 21, 2016, 01:29:05 am
content: Quote from: Asavage9794 on May 21, 2016, 01:15:07 amBy "rule areas", did you mean rural areas? If so, the power lines are usually single or 3 phase 11KV with step-down transformers near the properties. The transformers can be anywhere from next to the house to kilometers from the house and transformers can be shared by several properties. How are you going to get the LTE to bypass the transformers?

author: Asavage9794
author_rank: Contributor
timestamp: May 21, 2016, 02:14:47 am
content: That was a typo.. I never thought of the transformers they would drastically weaken the signal.

author: Asavage9794
author_rank: Contributor
timestamp: May 21, 2016, 02:18:33 am
content: Is there a negative lead on the power lines or is it just a bunch of positive lines?

author: edavid
author_rank: Super Contributor
timestamp: May 21, 2016, 02:18:59 am
content: Not a new idea:https://en.wikipedia.org/wiki/Broadband_over_power_lines

author: LabSpokane
author_rank: Super Contributor
timestamp: May 21, 2016, 02:19:51 am
content: Quote from: Asavage9794 on May 21, 2016, 02:18:33 amOK, I have to ask. How old are you?

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 21, 2016, 02:21:23 am
content: Quote from: Monkeh on May 21, 2016, 01:27:42 amI was able to modify a pair of cheap Zyxel Homeplug adapters to get nearly 600Mbps over a few hundred feet of old phone line, even though I was only using one of the three pairs in the cable. Breaking a gigabit should be trivial if you apply the use of MIMO to all available pairs. The Homeplug adapters I used were limited to a 12V output driver, but higher voltage drivers could be used to get better SNR on long lines.Now as for power line WAN links, the transformers attenuating high frequencies is actually an advantage for the backbone link since they would attenuate many sources of noise. Add some repeaters to get the signal to the customers. Underground power lines would perform much better than above ground due to the ground attenuating noise.All in all, it would be much easier to use phone lines if there are working ones still available. Not having to deal with very high voltages and lots more pairs available really helps with implementation. Or if it's a clear environment, zap lasers from point to point.

author: Asavage9794
author_rank: Contributor
timestamp: May 21, 2016, 02:28:27 am
content: Quote from: LabSpokane on May 21, 2016, 02:19:51 amI am 21 years old.

author: XOIIO
author_rank: Super Contributor
timestamp: May 21, 2016, 02:31:38 am
content: Quote from: Asavage9794 on May 21, 2016, 02:28:27 amYou do know that household wiring is AC right? (I mean, you need that to put any type of a carrier signal in between the sine wave peaks, which is what your idea would need to do). There is no positive or negative, plus, if it was all positive, how would the circuit be complete?

author: Marco
author_rank: Super Contributor
timestamp: May 21, 2016, 03:19:52 am
content: Not unless you had a repeater on every pole, oh and it would radiate.Just make a law to guillotine anyone who opposes putting fiber on the pole and the problem is solved (in a nation using poles for electrical distribution).

author: amspire
author_rank: Super Contributor
timestamp: May 21, 2016, 03:27:30 am
content: Quote from: Asavage9794 on May 21, 2016, 02:14:47 amTrying to get high speed data through a 50/60Hz power line transformer would be impossible. Even in suburban areas, there are still transformers, and so any network using the power lines would only reach a limited number of local houses connected to the same transformer secondary. Also Mains is 3 phase, but most houses are only connected to one of the phases so you are probably not connected to the same phase as your friend down the road.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 21, 2016, 04:00:59 am
content: Power lines make terrible transmission lines:- The insulators are lossy, typically PVC. Hopeless above, say, 100MHz, so don't expect much more than comparable baud rate. (If the noise level is low, you can still throw in lots of bits per symbol, but I wouldn't count on more than a few.)- No impedances are controlled. Romex will be around 100 ohms, but unbalanced. Plastic junction boxes will radiate randomly. BX, conduit and metal boxes will have reasonable shielding, for the most part, but random impedances in the vicinity of 100 ohms (differential). And mismatched propagation delays for each conductor versus ground.- Random networks. Circuits are typically chained straight from the panel, but frequently, they branch to reach multiple locations. Certainly, it's uncommon that a single outlet (where you've plugged in the modem) will be at the end of a straight circuit.- Dispersive and generally nasty loads. Transformers and motors will absorb RF unevenly (add phase shifts and attenuation to random length reflections), SMPSs will generally reflect as shorts (due to the X type capacitors in the filter), and unfiltered rectifiers (CFLs for example) will alternately reflect (open vs. short) RF, leading to huge backscatter modulation!And that's just for a circuit. Where the circuits meet up at the panel, half and half go to either side of the power company's transformer (US mains). Even if the reflection and attenuation from 5-10 circuits (per side) branching at the panel isn't bad enough, you've got a split-brained house where half the outlets randomly won't communicate as well with the other half.Let alone between houses. The wires on the power poles are usually widely spaced, so that the impedance will be more like 200-300 ohms for a considerable distance (blocks?). The transformer itself will probably be a reasonable short to RF (being made of heavy copper or aluminum strap), adding yet another reflection to the mix.But all that still isn't insurmountable. You can do what DSL does, and use a massive array of relatively narrow channels. By testing each channel for performance, you can figure out the available SNR and therefore bitrate for a given link. But you're still left with two problems:1. You aren't guaranteed to find any single channel that's good enough to use, even at low bitrate;2. You can't radiate higher than Part 15 limits on conducted and radiated EMI. Which is, coincidentally, also the (hopefully) worst case noise floor you have to work against.So, most of the time, on most channels, your SNR will be negative. You'll get lucky breaks between bands of EMI, and where reflections manage to reinforce rather than null your signal along a given path. But I can't imagine these are all that common, and still, we're talking about between neighbors at best.It's way more practical to just run CAT5 into everyone's house; or better yet, use an existing twisted pair, like DSL, or better still, coax cable!It's a horrible premise, with an awful solution, in search of a problem that doesn't exist!Tim

author: Asavage9794
author_rank: Contributor
timestamp: May 21, 2016, 04:04:30 am
content: Hmm would a LTE signal go over a telephone line?? Almost everyone has a phone line going to thier house.

author: Asavage9794
author_rank: Contributor
timestamp: May 21, 2016, 04:17:30 am
content: Quote from: Marco on May 21, 2016, 03:19:52 amYou could but the United States is a big land mass and it would hard to give fiber or docsis 3.0 to all residents.

author: Asavage9794
author_rank: Contributor
timestamp: May 21, 2016, 04:20:42 am
content: There is satellite but but from what I hear it has horrible latency and data caps

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 21, 2016, 04:58:14 am
content: The first time I saw this idea was sometime in the 80s or maybe the 90s when "broadband" over power lines just had to be faster than a 56K baud phone modem. No one was able to make a commercial go of it under those circumstances.I am in a rural area where satellite is the only option. It is no good for gaming, and does have data limits, but not too onerous. I am pretty happy with it for my needs. It isn't cheap, but not that much worse than general US internet prices. The cheapest version is 50 USD/month for 10Gbytes of data (with free data late at night). Next up is 75 USD/month for 20Gbytes of data, again with free data late at night. The upper tier plan has no data limits and costss 100 USD/month. While those aren't terrific prices I suspect that they are low enough to keep any competitive services out of much of the rural US. Laying cable or fiber and/or putting lots of switches and repeaters around is an expensive proposition.

author: kc8apf
author_rank: Regular Contributor
timestamp: May 21, 2016, 05:07:16 am
content: Quote from: Asavage9794 on May 21, 2016, 04:04:30 amI highly suggest you do some reading on how LTE's radio access layer works. It's designed for a shared medium where the eNodeB controls who gets a time slot on a given set of subcarriers. The channel bandwidth makes it a poor fit for power lines. The shared medium design is entirely wrong for phone lines. It might work over a cable line but wouldn't be any better than DOCSIS.

author: Asavage9794
author_rank: Contributor
timestamp: May 21, 2016, 06:23:50 am
content: Okay,I guess theres no way to have LTE over power lines, and or Telephone lines. But I would like to figure out how to give people in rual areas faster internt.I have experence with internet in rual areas in the United States, the max speed that dsl can get here in Illinois is 10Mbps down and 1Mbps up. The service was shitty i had 3Mbps down and 512k, Heres a link for egyption telephonehttp://www.egyptian.net/High_Speed_Internet.htmlThe service was slow and spotty as the isp was like in Steeleville, IL, US 22M(35Km) away.Theres also frountierr. Frontierr offers speeds of 6mbps down and768k up, but in reality you actually get like 1mbps down and like 512k up. and its very spotty also

author: kc8apf
author_rank: Regular Contributor
timestamp: May 21, 2016, 06:47:22 am
content: There's no silver bullet for that problem. As you get farther from the telephone CO, the signal quality over the lines gets worse. Cable television systems are pretty good for high-bandwidth signals but they need a lot of amplifiers. That's one of the reasons many rural areas don't have cable TV. Satellite is expensive, high-latency (at least for GEO/MEO), and usually the bandwidth is highly asymmetrical (high bandwidth down, low bandwidth up). Wireless (licensed point-to-point, not cellular) is sometimes available and works pretty well in good weather in the plains. Of course, if you get LTE service where you are, you can always but LTE modems or gateways.

author: XOIIO
author_rank: Super Contributor
timestamp: May 21, 2016, 07:04:31 am
content: Directional antennas are the best way to go about this sort of thing if satellite is that bad price wise, there are directional wifi antennas with ludicrous range.

author: borjam
author_rank: Unknown
timestamp: May 21, 2016, 08:06:06 am
content: Today it's much easier to install fiber. Thanks to the passive optical networks, the costs have gone down dramatically.That means, it's not expensive to install it, being optical fiber it will have a very long service time and thanks to its reliability the technical support costs will be really low.

author: John Heath
author_rank: Frequent Contributor
timestamp: May 23, 2016, 03:15:17 am
content: There are smart house hydro meters that give credit for power use at low peak hours. These meters communicate over hydro lines your power use time stamped. There is a name for it but I can not remember. It was low frequency sub carrier to get through power transformers. Baud rate 120. It sends a small pulse right at zero cross over point . Hydro will pole meters by the address to harvest data. Way too slow for internet , ha . Just remembered the name. If you google TWACS it will come up.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 23, 2016, 01:49:02 pm
content: Quote from: borjam on May 21, 2016, 08:06:06 amDo you have any links? When I do searches the returns are saturated by ISPs offering fiber in urban regions.While satellite is serving my needs I might be interested in financing my own fiber to the nearest decent hub. In my case that might be 20 or more km, but I can probably sell connections to a few dozen others nearby. It is worth looking into, although I think you are optimistic on either support or installation costs. Trenching makes underground installation expensive. If done above ground, on shared utility poles (another tricky point), things like trees falling down, vehicles knocking poles down and so on are more important in service time than the intrinsic strength of the cables.

author: borjam
author_rank: Unknown
timestamp: May 23, 2016, 01:58:16 pm
content: Quote from: CatalinaWOW on May 23, 2016, 01:49:02 pmCertainly.The passive equipment I'm talking about is DWDM equipment. Each customer is put on a different wavelength and you create a bus with a band pass splitter for each different customer. The up front cost per customer is fairly low,apart from the fibre installation itself, and this is pretty good for low density deployment in rural or industrial areas.If I remember well, you could connect like 16 customers to a single fiber strand, which is quite good. The tunable DWDM weren't expensive and the service was just Ethernet, nothing fancy and complicated, which means that the CPE costs are low as well.Regarding trenching, there is a fairly new technique called microtrenching.http://thefoa.org/tech/ref/install/Microtrenching/index.htmlhttp://www.bbcmag.com/2009issues/may-june09/BBP_MayJune09_MicroTrenching.pdfIt's failry quick and unobtrusive to do. A friend considering a deployment to a failry remote rural residential area told me that the costs were surpsingly affordable. Worth having a look.

author: ConKbot
author_rank: Super Contributor
timestamp: May 23, 2016, 02:04:35 pm
content: Quote from: CatalinaWOW on May 23, 2016, 01:49:02 pmHow flat is the area you're in? Got any friends or business relations within line of sight (Even with a small tower or pole) that have access to the sort of high speed youre looking for?https://www.ubnt.com/airfiber/airfiber5/operates in unlicensed frequencies so should be simple to get set up. (Probably simpler to set up then dealing with whatever sort of licensing nonsense a business ISP would need for a person re-selling bandwidth)

author: Marco
author_rank: Super Contributor
timestamp: May 23, 2016, 02:12:33 pm
content: Quote from: borjam on May 23, 2016, 01:58:16 pmIf they have utility poles it would be rather stupid to be forced to trench for fiber ... not unlikely, but stupid.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 23, 2016, 05:32:56 pm
content: Thanks for the suggestions. I'll have to look into it. I have limited line of sight to possible connections, and when I looked into it earlier costs were a few of times higher than the price in your link. I would also have to develop contacts as I do not have line of sight to anyone in my current circle of friends. As I said earlier, satellite meets my needs so it hasn't been an urgent pursuit. The only way the fiber connection would make sense would be if I could get others to participate. The major cable companies have decided that the customer density is not high enough to be worth servicing the area, but it might make sense if not pursued in a venue where quarterly stock performance matters.I has been more than 40 years since I was involved in shared use of utility poles, but it was a huge issue then. Lots of lawyers involved argueing about sharing of maintenance costs, liability issues and the like. Even for companies that had long standing agreements there was always a bunch of negotiation anytime there was a new installation. It is not all stupid. How do you arrange for all parties involved to be on hand to do a pole replacement? Do you want a telephone technician moving high voltage power lines and or a high voltage lineman handling fiber optic cables?Trenching, even micro-trenching requires right of way and going under road crossings and the like. Not cheap.

author: Marco
author_rank: Super Contributor
timestamp: May 23, 2016, 10:51:28 pm
content: You don't have to pay 2k$ a piece, unless you absolutely need the 1.2 gbps. Ubiquity and Mickotik have much cheaper solutions based on dishes with outdoor versions of more standard wlan modems. You'll pay around 2x200$.Alsothisorthisif you want to go really cheap, don't see many reviews of them online though so caveat emptor.