Electric Plug 14Mbps Spec Agreed On 102
Tei'ehm Teuw writes: "From this article
on EDTN the effort to establish a standard for
power-line-based home networking will take a step forward
this week when the HomePlug Alliance announces it will adapt
technology from Intellon Corporation for its specification.
The 36-member alliance will release a complete specification based on Intellon's
technology, with its 14-Mbit/second raw data rate.
In Europe, meanwhile, the HomePlug Alliance has established formal liaisons
with two groups working on power line
home networking: the European Telecommunication Standards Institute and the International Powerline
Communications Forum. Neither has defined a technology to date,
but it would be possible for them to adopt the same technology as the HomePlug Alliance, even though the European power line access technology is
different there than in the United States. (The European power line delivers 220 volts at 50 Hertz; in the United
States, it's 110 V at 60 Hz.)
The overall forecast for power-line-based home networks is now beyond the 32 million
nodes initally projected."
Re:HOME networking (Score:1)
Well, that's ass-backwards, but yeah. Voltage is actually the electrical pressure - rather like kinetic energy, whereas amperage is the actual movement of electrons.
It's the volts that jolts but the mills that kills
A simple application of ohms law will yield the maximum safe voltage. Ohms law is E=I/R, or voltage = amps * resistance...
So, we know most people's skin, when dry, has a resistance of about 1.5k if they are NOT grounded. If they are wet and grounded.. well.. let's just say they have about as much resistance as a hunk of 4ga wire. Anyway.. plug this into the formula...
E = 0.005 * 1500
.. which yields a voltage of: 7.5
That is your maximum "safe" DC voltage. This means that anything under 7.5 volts you can sneeze at without worries. :)
X10 (Score:1)
ECHELON (Score:1)
Not a troll, seriously, how secure is this compared to say, modem/phone, cable modem, etc...
EMC questions ..... (Score:1)
Re:competition (Score:1)
Mike Roberto (roberto@soul.apk.net [mailto]) -GAIM: MicroBerto
Re:competition (Score:1)
What costs more, ripping up a three or four story Victorian house with mint-condition woodwork to run standard structured cabling, or buying into a scheme like this? For new construction or serious tear-aparts it's tough to beat a structured cabling scheme, but for existing construction where there are severe limits on where and how you can run cables, this seems really nice.
As far as speed goes? 14MBit is ideal for controlling your VCR from your satellite box, monitoring your fridge/AC/furnace from the PC or any of the other home automation things. Even better this may enable 'smart' device application-layer interfaces (think SNMP for home applicances, but without the annoying which-MIB-is-supported grief) common across vendors, applicances or other devices.
Even if it remains a computer-only interface, think of printing without any cable other than a power cable, etc. Hell, it would beat playing doom over arcnet..
Re:The *real* application of this stuff.... (Score:1)
They use that time signal to switch back and forth from 'Economy' rate overnight...I assume other countries use similar systems? Anyone?
Doesn't anyone wonder about security? (Score:1)
outlet in a house's backyard and gain access to their
network. I can imagine lots of problems like:
- turn off that noisy stereo (air conditioner, washer, etc)
- gain access to the DSL link, send spam or
incriminating email
- gain access to a computer
I wonder how many houses will be set up with a filter
on external outlets?
Re:HOME networking (Score:1)
I have no idea where you're getting this 1.5k ohms as body resistance. Hell even wet (spit, a great conductor) 1" of skin measures about 800kohms.
First off, you don't say for how much skin. The more skin between the probes, the more resistance.
I've got an ohmmeter on me right this minute and I can't get below 12M on my fingertips. My arms won't even register so it's above 4000Mohms (Fluke 87 III making the measurements).
Also remember that AC resistance and DC resistance are completely different. I may be over 4000Mohms with the ohmmeter but you feel a lot more if you hit yourself with 240VAC. Part of it is skin effect (the AC will travel along the skin, but I imagine 60Hz will penetrate the skin more than straight DC along the surface since it is probably a little more conductive *in* the skin rather than just *on*). I work in industrial power electronics and have been bitten a few times by 575VAC. 90A breakers have a lot of let-through before they trip, and the only reason I'm still here is because the bulk of the current wasn't through me. One of our sales critters got a blast of 4160 when he tried to measure the width of the stacks with a metal measuring tape and my old manager (he's alive, just in a different department) got 4160 across the chest through a power factor capacitor.
Perhaps the weirdest feeling I ever had was when load-testing a 1200A starter. We took a big 50 gallon plastic barrel and filled it with cold water. Then we put the resistor bank in. Our power source was 208 going down to about 8V through one of our big step-down transformers for load testing. a 208:8 transformer would allow us about 5000A of current.
Needless to say the water got pretty warm pretty fast. The neat part was when the president grabbed me and said "Put your arm in it!" When I did so I didn't feel anything at first but when I stuck your arm in the warm water (about 40 degrees C) up to about my elbow, all the muscles in my arm (fingers, wrist, forearm, all of them) started to flex and unflex because of the current flow.
Where was this current flow? From my arm, through my body, through my shoes and to the concrete floor. I was AC-coupled. Very poorly but it was definately one of the weirdest feelings I've ever had. If you know what you're doing it's definately worth doing just to feel it.
Anyway I just meant to comment on your human body model. The most common I've heard is a 1Mohm resistor to ground, not 1500 ohms.
Re:Nice, but... (Score:1)
Only if you want the outside world to be able to talk to your lightbulbs and fridge! All those kind of devices can live in a non-routed IP class; if they really need to be externally managed then only the 'main' control system would need a real IP.
Re:First questions that spring to mind... (Score:1)
Re:Media Fusion Gets Around Transformers (They Cla (Score:1)
Re:HOME networking (Score:1)
That may be due to the capacitive effect the body has, but I doubt it would have a significant impact. Besides, by the time you start pumping serious amperage through someone they're already dead.. so capacitance doesn't mean much now does it? :)
Re:Apartment Buildings (Score:1)
Hey John! :-)
Security is solved doing what wireless does now: encryption. Take it a step further (or sideways, depending on how you look at it) and incorporate it right in Layer 2 in hardware, a la GuerillaNet.
Bandwidth is bandwidth. There'll never be enough. Once this progressed to a switched-style network (this is a neat concept in and of itself) it'll alleviate both problems by providing "virtual" point-to-point networking.
HomePNA 2.0 (Score:1)
Except...
There's still no driver support for HomePNA under linux. Not 1.0 (1mpbs) or 2.0 (10mpbs). So I'm stuck using a Win98 box as a mixed-media router! I looove having a firewall that crashes once a week and needs nightly reboots!
Can someone point me towards a driver (ANY driver, beta, alpha, I don't care) so I can use my HomePNA 2.0 cards under Linux?
(and no, I can't rip up my house to install cat5; we're about to sell it)
Re:HOME networking (Score:2)
I have no idea where you're getting this 1.5k ohms as body resistance
1.5 kohm sounds about right. That's *body* resistance, measured with a good connection to internal fluids. Of course, most of us don't implant electrodes to measure this. ;-) You were measuring *skin* resistance, which depends on many things, including saltiness, moistness, skin thickness, and skin composition. With small electrodes on dry skin, it measures anywhere from 100 kohm to >100 Mohm.
Try repeating your measurements, but with reduced skin resistance. Make each electrode a big wire, one of which is squeezed in each hand. And drench the contacting skin with salt water. I just did this and got 20 kohm. And the skin is *still* a significant impediment to current. So a 1.5 kohm body resistance is reasonable.
Nope. The skin effect (unrelated to human skin, BTW) is mostly negligible at 60 Hz. At 60 Hz, it's only important for huge generators dealing with thousands of amps of current.
"Put your arm in it!" When I did so I didn't feel anything at first ... all the muscles in my arm (fingers, wrist, forearm, all of them) started to flex and unflex because of the current flow.
Stupid, stupid, stupid. It's things like this that earn Darwin Awards. A portion of the current was certainly flowing through your heart. It just wasn't enough to cause immediate cardiac arrest. And this is the most dangerous situation possible, because your heart may have been silently damaged. Plenty of people have gotten shocked, counted their blessings for not being killed, gone home at the end of the work day, and quietly died in their sleep from delayed heart failure. A quick trip to the friendly emergency room cariologist will show any subtle injury to the heart -- the heart's electrical waveform usually changes significantly when it is seriously injured (AFIK).
Re:If they Run on power lines? (Score:1)
See how your question makes no sense?
It is all about configuration and doing it correctly.
Re:EMF and Security? (Score:1)
However, Rediffusion installations generally used a dedicated network. So it might be that all networked things need to be on their own circuit, etc. Not beyond the realms of possibility, but if you start talking dedicated networks you may as well be installing CAT-7...
Re:HOME networking (Score:1)
I should be dead several times by your standards since I have touched 220V outlets several times....Funny fealing BTW
Jeroen
Re:Similar thing trialled in the UK.. (Score:1)
Jeroen
Re:First questions that spring to mind... (Score:1)
Noise isn't a function of the frequency or modulation.
Yeah, but I was saying if you want to dampen a signal with a cap, the frequency has an impact on the capacitive reactance of the cap.. sorry, perhaps that wasn't clear 'nuff..
The supply and cap would be fighting each other, hence a recreation of the big bang.
If you're stupid enough to not to properly rate it.. or use an electrolytic on it! Otherwise, all it does is create resistance in the circuit.. I was thinking of something like a tank circuit / band pass with the capacitor to have the lowest impedance at 60hz. Presumably the frequencies you want to block are in the Mhz range, and hence would be highly attenduated through the circuit!
Quite how this system works in conjunction with UPS's, though, is the interesting question...
When a UPS detects a drop in the line voltage, it usually trips a relay inside it .. hence your UPS will never "bleed" energy back into the lines..
The *real* application of this stuff.... (Score:3)
Not everybody wants an ethernet jack on their toaster, but _everything_ has a power jack.
Imagine the following:
- buy a new VCR/DVD Player/Alarm clock? Plug it into the wall, and watch it set the time on itself to the same time as all the other devices in the house.
- Self-monitoring appliances that are syslog() capable (or something similar) and report faults to a central logging facility
- Appliances that export network APIs to provide scriptable control
...and a host of other Really Neat Stuff possible if you have a standardized network in every home.
Re:HOME networking (Score:1)
Obviously putting your finger across an electrode while you are ungrounded would have significantly less impact than a finger from each hand and putting the charge across the heart.
btw - don't let that "funny feeling" last too long.. internal / RF burns suck. REALLY suck. No, no, I don't think you understand: THEY ARE THE MOST PAINFUL THING YOU CAN POSSIBLY IMAGINE.
Re:intra-building network (Score:1)
I've been wondering how far this sort of thing would work in an apartment complex (on USA power lines, if it matters). Could people in several apartments form a "clandestine network" on the existing powerlines to communicate with each other, and if so, how close would the apartments have to be to one another? Also, could someone build "repeaters" to boost the signals from the other end of the apartment complex, or a signal amplifier (much like the "long range FM radio antenna amplifiers" that occasionally get advertised) that would amplify and clean up the incoming signal, to boost the effective range?
Somebody (perhaps more than one somebody) in one of the other stories (one of the "perversely wealthy corporate bastards with rabid legal department stomps all over internet freedoms" stories, I can't remember which one) made a brief comment along the lines of 'maybe we should form our own internet'...could this be a way to do it?
Joe Sixpack is dead!
Re:Everything you said plus more.... (Score:1)
Yeah, but your house does 250 amps, I bet.. the building I'm sitting in right now I betcha does over 2000. That, umm, kinda makes a difference. :)
I don't string my cat5 anywhere NEAR my power cables
You can do that all day long if you run them at 90 degree angles relative to each other - that way you get minimal interference between them. Worse though is leaving them all coiled up - inductance can cause some serious problems over long lengths of cable.. like what you might find behind a patch panel.
We'll have inferior bandwidth at home, subject to all the power line noise you described. And don't expect the house to be sold/built any cheaper for the lack of a real cat5 network either.
I already resolved, like many of my geek friends, to live only in neighborhoods with high speed options available.. they'll come around - it is all a matter of market demand and as people become clued about this it'll become alot more prevalent.
Re:First questions that spring to mind... (Score:1)
As for the UPS, I was talking more about how they expect the signal to get through it.. and it also depends whether you have an active or passive UPS. Most good ones completely separate the mains going into the UPS from the mains going out - they're completely isolated. Hence, no data
Treu enough, but... (Score:1)
>building I'm sitting in right now I betcha does
>over 2000. That, umm, kinda makes a difference.
Yeah, but the building I work in is n SF's SOMA district and was renovated two years ago specifficly for the purpose of housing technology companies. Plus, my home circuit is all ME. At home I prolly use more amp/person than the office does w/ one refridgerator split between 40 people, etc.
Plus, I live in an OLD house. You'd be supprised how old some of these homes in SF are. I don't even want to imagine what kind of spec my home electric wiring is up to, or how old it is.
Some big streaches of SF are in need of some MAJOR urban renewal. But the city planning board makes it INCREDIBLY difficult to demolish and redevelop ANYTHING.
john
Re:HOME networking (Score:1)
You are correct, though, that much more current would flow if I was wet. With moist fingers I can get the resistance down to 50k Ohms or so, or 180 microamps from a 9V battery. I personally wouldn't even worry about taking a 9V battery into the shower with me.
Hey, a lot of people stick 9V batteries on their tongue to see if they're dead or not.
The European safety standards specify about 30V (it might be 32 or 35 or so) as the "safe" voltage level. Any voltages used in your product above 30 or so volts have to be protected from coming in contact with anything (i.e. a finger) but below 30V no protection is required.
Two phase power (Score:1)
But how safe is it ? (Score:1)
My EFI/RFI filtered power strips EATS X-10 signals (Score:1)
Re:Troll? (Score:1)
power line dsl... (Score:1)
the bog... (Score:1)
that has to break a run-on sentence length record somewhere...
RFI (Score:2)
Re:HOME networking (Score:1)
Only on a good day, most of the time it would be substancially less.
Networked appliances (Score:1)
Privacy Concerns? (Score:2)
competition (Score:2)
available now? (Score:1)
Re:competition (Score:1)
Yeah, but it'll still be much better than the 5 kilobytes/second download rate you get from a modem on a good day, even if the 14 mbps is shared bandwidth.
Cable modem or ADSL aren't user-serviceable beyond the plug in the wall either...
Does this mean... (Score:3)
Similar thing trialled in the UK.. (Score:2)
Oh.. and it's 240v at 50 Hz in the UK.... BTW.. which, as *everybody* knows, ain't strictly Europe.
t o b e
First questions that spring to mind... (Score:2)
This sounds pretty sweet, but... There is no heaven on earth... Things are not usually as perfect as they seem...
Re:Privacy Concerns? (Score:1)
Cable modem and wireless LAN are encrypted, and I see no reason why this wouldn't be, too. The encryption isn't very strong (40 or 56 entropy bits RC5, or something like that) but it's enough to keep the neighbor from tcpdump'ing one's connections, at least in real time.
EMF and Security? (Score:2)
This is not good for EMF and for security of course.
Re:Does this mean... (Score:2)
HOME networking (Score:4)
The reason that an ISP->user connection will never be feasible across powerlines is due to transformers - the moment you put a signal through a transformer you get garbage out the other end.. that's the downside of transformers - and why you can't use load coils with xDSL. The second problem I see with this is that because of the high voltages involved, it is quite possible to kill yourself.. well, the voltages don't kill, but use alittle ohms law and you'll figure out why high voltages are a problem (for reference, your body is about a 1.5k resistor and your max safe current is 5mA with lethal at 30mA).. anyway.
I also think the technology will be limited SOLELY to the home market - if I was IT manager I wouldn't let my company even *think* about deploying it.. you have all kinds of nasty things in commercial/industrial settings on those wires that just make it totally unreliable - a blown circuit breaker takes out your network, phase shift from flipping on the refridgerator, all those flourescent lights severely throw the phase out of whack - you're left with anything *but* clean energy in a commercial setting.. this is why power strips are so VERY VERY VERY VERY important.. and UPS' on anything worth a damn.
So, uhh, don't expect this to be any kind of "long term" tech - it'll be around for about 10 years tops.. most new buildings these days have cat5 and coax drops just per default.
Will this be Compatible with X-10 (Score:1)
Re:First questions that spring to mind... (Score:2)
Not very well. At best it is essentially a massive hub. At 1.5MB/s, that means that you will never break 700k/s with more than a couple nodes chatting.. just like you would with any other half-duplex hub.
How many nodes will we be able to have on a single circuit?
I'd peg it at 5, tops.. and that's optimistic.
How well will it deal with electrically noisy circuits?
That is a function of the frequency and the modulation.. I cannot answer that.. however I would assume the error rate would be fairly low - maybe 1 per 10^9 ?
Will it be possible to isolate my network from my neighbor's?
Practically speaking, no. You can use different frequencies, of course, but the signal still gets there. A sufficiently large capacitor could remove enough of the signal.. but without knowing the frequency I can't tell you what size cap you'd need!
Re:HOME networking (Score:1)
Assuming you're wearing rubber-soled shoes and are dry. Obviously if you get out of a shower and hook yourself up to a 9V battery you'll be in for a suprise. :}
Usefulness (Score:1)
Now of course immediately, the usefulness in networking is with computing devices, most of which are pre-equipped with Ethernet capability, and most of those at 100bT. But perhaps the real future here is in other kinds of networked devices. As it becomes more feasible to network your coffee maker, lights, microwave, alarm clock, and other household appliances, I can definitely see the value in using existing network architecture rather than installing a whole new one.
The one technology I see as the killer here is wireless communications. If we're talking intra-unit communications, the advantage easily shifts toward 11mbps IEEE 802.11b. Yes, it's slower. I'm getting a good deal less than 11mbps (more like 2), but it works. It's shipping; it's here. And I predict that by the time we see a working system based on this new technology the bugs will be worked out in the wireless sector. That would effectively make the power-line-based system obsolete before it's even a reality.
All we need is bandwidth comparable to today's Ethernet (100bT, not necessarily Gbit) and a range increase on an order of about 2-3x (can almost get this now with an external antenna). I could easily see running an entire household worth of appliances off of such a network, and possibly hook a few personal computers in as well.
Re:EMF and Security? (Score:1)
Every frequency across the board will have problems because the transmission lines are so long. The trick is lowering the output to the point where the FCC doesn't complain, and maybe making it broad-spectrum... considering this is only feasible for home use we're talking maybe 1/8 watt transmission.. it's not like it has to go very far!
intra-building network (Score:1)
One major hassle would be connectivity in the building. Mainly for the social engineering needed to persuade non-geeks to put another cable in their walls. Solutions like this could help, if they mature soon enough.
I also though of using inter-phone lines. I know there are products meant for offices internal phone lines. Anybody knows aho fast/good they are?
Re:HOME networking (Score:3)
You said, "If they are wet and grounded."
Yeah, if you're grounded you're in deep trouble. A guy I used to work with has this bumper sticker: "Electricians' kids are never grounded."
Yeah, I did electrical work to pay my way through college. I don't have a degree in physics but I know enough about electricity to be safe.
As for the wet part, isn't it the salt(s) in water that conducts electricity? I recall doing some labs in high school physics class that showed that distilled water makes a lousy conductor. Of course, water loves to dissolve salts, so your distilled water quickly becomes "contaminated" and a good conductor if you do something silly, like stick your hand in it. Again, correct me if I'm wrong.
Re:Apartment Buildings (Score:1)
This would be a very similar situation to the one I had in my college dorms. We had 10baseT in the building without switching. Naturally, privacy was more or less a joke unless you encrypted everything, but on the other hand most people on your segment didnt have much of a reason to eavesdrop.
Bandwidth was not a problem due to the fact that the universities outbound line was the real bottleneck. However, I could see this becoming a problem in a large building where everyone has different providers. Perhaps this could be solved by apartment buildings leasing their own frame relay lines and including power line networking in the lease.
The security issue is really the reason that people need to move towards encrypted layer 4 protocals (authentication is nice too). TLS sounds like a great solution for this, as you dont need to worry what is being sniffed (it is like tcp but fully encrypted).
Re:competition (Score:2)
Even if the bandwidth was significantly less, this opens a huge door for "smart" homes and appliances. The "average" consumers are more likely to buy a fridge that doesn't require an ethernet cable snaking around their home. I can't see my dad wiring cat5 in his house, but I can see him plugging in a home monitoring system that knows when he left the oven on.
----
Re:Will this be Compatible with X-10 (Score:1)
The real question is: When will the price drop to X10-like levels? Using this for simple off-on control is massive overkill, but if chipsets are cheap and can be hooked to PICs, well, why not?
Re:competition (Score:2)
Cat5 might be cheaper on the endpoints, but you have to consider the cost of getting the wires in. Most people's homes don't have Cat5, and I would question anyone who says that any more than a small percentage of new homes are getting Cat5 in them. Most people don't have multiple computers strung about the house, nor do they care enough about their computer to get extra wiring put in for it.
If you just want connectivity between points in your house, this is undoubtedly much cheaper than ripping your walls out to put Cat5 in.
-Matt
Re:HOME networking (Score:1)
Re:HOME networking (Score:1)
In one finger and out the other causes some cool muscle spasms, though. One downside of electrical shock is that it can tense your muscles, strenthening your grip on the item that is shocking you, causing better contact... etc... don't grab lines with your palm...
I've only once suustained a burn, and that was about 3-5 seconds of contact (seems like forever, though...)
Re:Nice, but... (Score:2)
Good point. Very few household devices would need to talk to the outside world. Although perhaps more than at first glance. Your fridge might want to talk to its manufacturer (or vice versa) for software updates or service calls if it detects a problem, for example. Your blender might want to conduct an email love affair with that cute toaster oven it sat next to on the store shelf. That sort of thing.
Meanwhile, how long before somebody builds a webcam into a light bulb?
Re:competition (Score:1)
Re:Doesn't anyone wonder about security? (Score:1)
--
Amarillo Linux Users Group [alug.org]
Re:intra-building network (Score:1)
--
Amarillo Linux Users Group [alug.org]
"Raw Data" means exactly what? (Score:2)
You wonder why I ask....
In 10Mbps ethernet, the 10Mbps refers to the capacity of the ethernet as a single, baseband channel. at perfect 100% usage, the channel will contain 10 million bits/second.
In practice, the maximum amount any single host can transmit, (full sized 1518 byte frames, smallest legal inter-frame gap (9.6uS, or 96 bits) equals about 9.9Mbps. Accounting for ethernet framing, fcs, plus ethernet headers, plus ip & tcp headers, and accounting for tcp acks... the max throughput on ethernet between two hosts doing ftp is about 9.8Mbps.
Fine you say... close enough. True.
T1 = 1.544Mbps, raw data rate. This translates to near 1.3 mbps (or higher, I forget) after PPP framing and whatever else is in there.
However... take many wireless networking protocols. Using whatever proxim's protocol (whatever they use in their rangelan-II radios)... a raw data rate of 1.6Mbps translates to a max uni-directional broadcast of about 800Kbps. About 600-700Kbps in normal TCp operation.
I've seen 11Mbps wireless gear that only does 5Mbps in useful throughput....
so.. in other words... be wary when someone says 'raw data rate' or 'throughput'... you (and they) will probably be unsure of what you mean.
Also..for any given medium, one has to take into account latency due to (c), the fact that there really IS no such thing as throughput.. a more relevant profile of a link is...
How many of what size packet can our setup move with what latency?
10Mbps ethernet again... it's a good example, because aside from the (frame+header)/(data) ratio changing with the size of (data).. it's efficient.
Many wireless devices I've tested aren't so lucky. Some of them perform just great trying to bridge 1518 byte packets, but then you get down to 64 byte... and they drop *way* off (processing bottleneck or something..). In other words... small packets take up much more than their fair share of resources in some devices... so in a common office ethernet, where 75% of the packets are 200bytes or smaller (not 75% of the total data.. 75% of the packets)... perhaps you don't get the throughput you think?
Why am I on this rant?
Cheers.
D
Re:First questions that spring to mind... (Score:2)
Gotta love mainframe technology overkill!
Re:But how safe is it ? (Score:1)
Can you imagine ... (Score:1)
Re:Voltage in Europe... (Score:1)
Re:HOME networking (Score:1)
Re:First questions that spring to mind... (Score:1)
230 volts! (It was 220 and 240 volts) (Score:1)
Some years ago it was 240 volts in the UK and 220 on the continental Europe.
A world-wide guide to plug and voltages around the world can be found here:
http://kropla.com/electric2.htm
Various Pointers to Using Power Lines for Comms. (Score:1)
Search for Powerline communications on this page
http://www.us-epanorama.net/tele_access.html
Ascom is/will start field trials soon.
http://www.ascom.ch/plc/int_home.htm
Re:Avoiding transformers (Score:1)
Re:HOME networking (Score:3)
Other than clearing up something that might be a bit confusing, I agree with pretty much everything the previous poster said.
Re:Does this mean... (Score:1)
Re:Similar thing trialled in the UK.. (Score:1)
We still have different plugs, though, and (unless they've made some significant changes to the ones on the other side of the Channel) long may it remain so...
Re:Similar thing trialled in the UK.. (Score:1)
Re:competition (Score:2)
Re:EMF and Security? (Score:1)
The biggest problem I can see with this system is that, unlike the slow old systems, this one is into radio frequencies (4-20MHz), which must surely cause problems for something.
Re:HOME networking (Score:1)
Exhibit A: The Van-de-Graaf Generator, which is incredibly good fun, but produces extremely high voltages.
Based on Intellon's technology? (Score:2)
Hmm... Just like Compuserve used gifs based on Unisys' technology, or mp3[*] is based on Fraunhofer's technology? I would be very careful to find out if the technology is encumbered by any current or pending patent claims before making it the standard. Whether or not the company says that it won't charge for the use of the technology, once enough people move to the new standard it starts looking real attractive to a corporation to go back on that agreement. Don't get fooled again.
[*] apparently Fraunhofer believes that their mp3 compression patent is broad enough that it is impossible to create mp3s (using any algorithm) without infringing on their patent.
Nice, but... (Score:2)
Time for IPv6? Or do we just put every toaster, refrigerator and light bulb in the house on an unroutable domain and handle the translation in the router/firewall/proxy built into the fuse box?
More seriously, this ain't bad. Speed is comparable to 10base Ethernet, but I'll still run Cat 5 cable in my new house (faster, and for now cheaper, since I already have the NICs and hub). One nice thing about signal-over-AC is that you don't need a separate cable to the device -- the power cord is the network cable, very convenient for appliance-type devices.
Random Thoughts (Score:4)
2. 14 Mbps is really impressive on a power line. (Lots of reflections, lots of noise, dynamic line conditions). I wonder if it really runs that fast? Has anyone seen a demo?
3. Intel's home networking product is a phone line product based on the HomePNA [hpna.com] (Home phone network association) spec.
4. Wireless is still more expensive than powerline and it has its own set of problems.
Re:HOME networking (Score:1)
Re:Similar thing trialled in the UK.. (Score:1)
Media Fusion Gets Around Transformers (They Claim) (Score:3)
Re:HOME networking (Score:1)
It's important to note that the amount of damage a current will do depends entirely on where the current goes. IIRC, it only takes one or two milliamps (or maybe less?) across the heart to stop it. Current going from one knuckle to another on the same finger will probably not do anything more than "weird out" some of your nerves and maybe give you burn.
Re:EMF and Security? (Score:1)
basically, they will need to do a lot with ensuring compliance of the electrical wiring in homes to minimize interference with licensed users of radio spectrum. i routinely find spurious emmisions from all kinds of household devices (including home networking stuff) all over the shortwave band, and occasionally up into the vhf band as well.
Re:First questions that spring to mind... (Score:1)
My new house has Cat-5 in the walls. I'll stick to that, thank you.
Re:Privacy Concerns? (Score:1)
umm, that is not neccessarily true. a lot of early wireless lan products, and quite a few on the market today, are _not_ encrypted. the newer, forward thinking products, fortunately, are.
you'd be amazed at how insecure wireless data systems actually are. when you are reading the specification for something and you run across the statement "the technical knowledge and equipment neccessary to intercept and decode this system is out of reach of the average person, making this an extremely secure system" it makes you scratch your head. this was [paraphrased] from the mobitex specification, which requires a handful of parts from radio shack and a bit of software.
be wary of _any_ wireless data product that does not implicity state it uses encryption, and states what the encryption algorithm is. a lot of protocols use something called 'bit scrambling' to maintain data integrity, and the marketing types always confuse this with encryption.
Everything you said plus more.... (Score:1)
Everything you said plus more bakes this a *BAD* idea for HOME networking as well as office networking.
Flouescent lights, refridgerator, space heaters, air conditioner, microwave oven... got em all.
I'd bet good money that the power signal in my HOME is just as "dirty" as at the office. Moreso I'd bet, actually. And yep, everything important is on a power strip/surge supressor, and the cpu boxen are all on UPSs. And I don't string my cat5 anywhere NEAR my power cables (actually, it's not even IN the walls, it's duct taped to the ceilings, walls, and floor OUTSIDE the walls).
>most new buildings these days have cat5 and
>coax drops just per default.
Most new HOMES have this too, at least according to an article in the Mercury News a while back. And this is EXACTLY why this is a horribly *BAD* idea for home networking as well.
What happens when real estate developers and builders find out about something like this? They'll think, "well, we can still sell a 'network ready' house, but skimp on all that cat5/coax cost". We'll have inferior bandwidth at home, subject to all the power line noise you described. And don't expect the house to be sold/built any cheaper for the lack of a real cat5 network either.
john
Safety (Score:1)
Apartment Buildings (Score:2)
Just a random thought, but what happens if you're using a technology like this in, say, an apartment building? Is it even feasible? Assuming that it is feasible, two things that immediately come to mind are:
Security might not be a big deal to most people, but I'm sure bandwidth would be. Things to think about....
Voltage in Europe... (Score:2)
At least, in the Netherlands, that is.
Could a DOS attack cause an explosion? (Score:3)
All those ping packets of x volts combined - boom!
Re:HOME networking (Score:3)
Here's a link [creighton.edu].
The reason you don't get hurt by a 9V battery (which, in fact, can deliver quite a healthy current) is because of Ohm's law. The resistance from one of your hands across your heart to the other is quite high. I just grabbed my multimeter and see about 1.5M Ohms, so the max. current that would flow from a 9V battery through me is 6 microamps, even though the battery will probably deliver at least an amp into a short circuit.
Re:First questions that spring to mind... (Score:2)
And no, a sufficiently large cap wouldn't remove the signal. A sufficiently large cap would blow up the sub-station - mains is AC, caps hold DC charge. The supply and cap would be fighting each other, hence a recreation of the big bang. (Actually, it's far more likely the cap would go, and yes, they do explode). I think you're thinking of DC power supplies there. But anyway, you can filter the mains, for about 20 UK quid (30 dollars) at most. And I can tell you the frequency easily: 50/60Hz band-pass. Pretty obvious, huh? Quite how this system works in conjunction with UPS's, though, is the interesting question...
Re:Similar thing trialled in the UK.. (Score:3)
The voltage is still 240V in Britain and 220V on the Continent. The new European 'standard' is 230V, but with a wide enough tolerance to cover both. See this page [std.com].