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Ninjahedge
03-26-2011, 11:46 AM
hey guys, quick ? before I go to an all-tech site on this one.

Question is, what is the best N router to use behind my FiOS router? I am currently using the classic WRT-54GS, but I would like to get better streaming through my home network (and possibly gigabit LAN from the server/main machine in the office).

A wireless router would be the first question. Second would be a Wireless PCI card for the HTPC, nodes for any other access point, or any other suggestions you guys might have.


As a side question, does anyone know a good automatic switch for VGA input? Composite input? I have so many things that I would like to hook up, but my older stereo only has so many available ports in/out that I can't hook everything I want up to it....

TIA!

Bald_Yew
03-26-2011, 03:30 PM
I'm still rockin' this one I got about 3 years ago:

D-Link DIR-655 802.11b/g/n Xtreme N Gigabit Wireless Broadband Router up to 300Mbps/ USB port x1/ Intelligent QoS (http://www.newegg.com/Product/Product.aspx?Item=N82E16833127215)

It is about $71 this weekend on the Egg.

shifty
03-26-2011, 03:57 PM
Go 5ghz wireless.

garm
03-27-2011, 12:36 PM
I'm still rockin' this one I got about 3 years ago:

D-Link DIR-655 802.11b/g/n Xtreme N Gigabit Wireless Broadband Router up to 300Mbps/ USB port x1/ Intelligent QoS (http://www.newegg.com/Product/Product.aspx?Item=N82E16833127215)

It is about $71 this weekend on the Egg.

I bought this for my friend. Paid $120 at the time and its been stellar. No issues and he has complete access in and around his house with is newly renovated and well insulated for noise, etc.

shifty
03-27-2011, 12:59 PM
Correction: Go 5GHz with 802.11n support - up to 300mbit speeds with 802.11n and using 5GHz = less interference than the 2.4GHz band, which is almost entirely saturated at this point.

If you can find something that does simulataneous dual-band (2.4 and 5.0GHz at the same time), buy buy buy. It will be current for the next ~5 years, rather than the current WAPs on market which will be unusable in a couple of years.

I just bought a Cisco (Linksys) E2000 refurb for $30 shipped. I thought it was bricked out of the box, but was wrong, patience pays off with regard to setup - I loaded DD-WRT and it's running like a champ with an ass-ton of features.

My E2000 offers either 5.0GHz or 2.4GHz (switchable) and since most 2+ year old cards won't support 5.0GHz (note: almost all reasonable newer cards support both). So I left my old Linksys WRT350N upstairs to do 2.4 for my wife's POS Mac and random visitors, then installed the E2000 for me and mine :)

Note that I upgraded my internal wifi card in my Dell Latitude D620 to a Intel 5300n wifi link card - easy upgrade, card cost $25 on eBay and requires no surgery to install. Most laptops *are* easily upgradeable if less than 6 years old, you just need to know if your laptop uses a half-height or full-height card.

shifty
03-27-2011, 01:12 PM
Additional notes:

I went 5.0GHz because our baby monitor was 2.4GHz and my wife and I would cause the baby monitor to clip and vice versa.

Also - Remember when speeds were limited to 54mbit on 802.11g? A lot of advances have been made to increase that. Like, I think it was MIMO technology that let you double-up the connection speeds and get 108mbit on a single antenna.

Pretty sure 802.11n adds the ability to use multiple antennae to add speed. What I've noticed is with 802.11n capable routers, if they have 1 antenna on the unit, the speeds are limited to 100mbit, if 2 antennae the top speeds are around 200mbit, if three antennae that's 270mbit-300mbit. I noticed the same with my draft-n-based card - it has three places for antenna connections; If I'm standing on top of my router with 2 antenna wires attached to the card up I get about 170mbit connection speed; with all 3 antenna wires attached, I get around 250mbit. Sitting downstairs right now with all three wires attached, I'm getting around 200mbit connection.

My E2000 also has gigabit LAN, so I don't have an instant bottleneck at the LAN. What's the point of having possible wifi speeds of up to 300mbit if you can only push data onto/off of your wired network at 100mbit? That's stupid. If a WAP only has 100mbit ethernet, this means you can only talk to wired devices on your network at 100mbit, even if you have a 300mbit wifi connection to the router; that's great .... if everything on your network is wireless.

Ninjahedge
03-28-2011, 07:54 AM
Thanks guys.

Here's the ting. I have a (Useless) Verizon router on the line right at the start to handle the initial in-house access point. I then wire it (100mbps) to the Linksys WRT. (I tried DD-WRT before, but I would have strange dropouts at regular intervals... i just gave up after a few hours of trying to get it to work...).

That WRT is wired to the server and main/gaming machine.

Around the house there are:
1 Laptop. I will have to see what protocols it supports.
2 "Slimline" music servers. I am 99% sure these are "g" only.
3 1 HTPC - Shuttle. I just fit an EVGA 7950GT card in there, so I am guessing it can fit "full height"

I think I would need to get a 2.4/5GHz simultaneous for this reason, otherwise I will have to junk those $250 music points.

One other thing, separate (I will ask on another thread if this gets too convoluted).

Netflix. Anyone have problems with tearing? I have looked all over and most say it is a problem with scaling and Silverlight software rendering. It gets really irritating watching something, looking at the CPU and BW stats and seeing <<50% usage but yet still getting tears and non-smooth panning and object motion.

Any clues? (I tried XBMC, they just bump you into IE. I tried Chrome as well. Nothing. I do not have FF installed, and the regular media players do not seem to be set up for Netflix.....)


Anyway, that is all!

TIA!

shifty
03-28-2011, 06:26 PM
i've never seen an 'n' capable router that isn't 'g' capable also, so that shouldn't be a concern.

i'm just convinced that you suck with custom anything. after your isolated bad experiences with Linux and DD-WRT ... i guess you're a vanilla-only guy, and custom isn't your forte ;)

Bald_Yew
03-28-2011, 06:53 PM
Don't n routers drop speed to the lowest rated speed on their wireless? I mean if you are going to keep a g device, won't the router slow to g? ...Or does this not happen with both radios on a dual band?

shifty
03-28-2011, 08:16 PM
I think you're confused.

2.4GHz, 3.6GHz and 5.0GHz are simply the modulated frequency that communication is occuring. 802.11 (http://en.wikipedia.org/wiki/IEEE_802.11) is the standard (protocol?) used to communicate over those frequencies. Your post implies that maybe you think the frequency and the protocol are somehow tied together?

Just like a multilingual person, a router is capable of talking in multiple standards with multiple devices at the same time without forcing everyone to talk the same language/standard. If not, someone using 802.11b would be able to hop onto your network and destroy all clients using 802.11g or 802.11n.

---


Also - Here are some examples of a respectable dual-band routers (outputting 2.4 and 5.0 simultaneously) - and mind you, I hate D-Link b/c their support and low-to-mid end products are shiet:

http://www.netgear.com/upload/flv/wndr3700landing.aspx
http://www.dlink.com/products/?pid=681

I think I may have implied or stated something about the antennae above - the # of antennae on the card affect the throughput of the connection, not the number on the WAP. Although, for some strange reason, I've noticed that WAPs with only 1 antenna seem to have lower max speeds. Could be coincidence.

Does this help, baldy?

Ninjahedge
03-29-2011, 07:57 AM
i've never seen an 'n' capable router that isn't 'g' capable also, so that shouldn't be a concern.

i'm just convinced that you suck with custom anything. after your isolated bad experiences with Linux and DD-WRT ... i guess you're a vanilla-only guy, and custom isn't your forte ;)


Possibly. But I break just about anything shift, including vanilla.

Programs crash on me all the time and not because I did something radically different, just enough different that had two things running at the same time that should not have been.

Linux was a problem because the media players sucked. None would que up a list (easily, w/o having to make a playlist), so watching 10 episodes of Bleach, on the HTPC, was a PITA if you kept having to open a new one up each time.

Then not being able to reformat the drive to get the half that was partitioned for Linux was fun too. I looked online, all I got was "that should not happen".

And the DD-WRT? The signal boost was great... but, like I said, something was not jiving and it would drop every 2 minutes or so. Then reconnect. This was not a common occurance, so there was no real info on it.


Instead of being vanilla, I think I should be called Beta. I know how to bring out the Beta in things even when they are Gold.

Ninjahedge
03-29-2011, 08:04 AM
Second post:

Shift, I think the speed may have to do with the ability of the wire to physically transmit that data. It sounds weird, but they may be a bottleneck in their own EM response time and will not be able to receive too many different signals w/o interfering with them... I will have to look up a bit more on that though....

As for what Garm is saying.... The only problem I had was not the B/G, but the security protocol? I could not use... I forget what the best encryption was, because my WAP could only handle the older one. Although that is a concern, I am not going to limit my entire households wireless system because of one wireless access point. I can always buy another down the road.

Thanks for the links to the machines. I will have to take a look and see if I can set them up with the same channel/name/PW so I do not have to reset all the machines in the house......

shifty
03-29-2011, 09:24 AM
Shift, I think the speed may have to do with the ability of the wire to physically transmit that data. It sounds weird, but they may be a bottleneck in their own EM response time and will not be able to receive too many different signals w/o interfering with them... I will have to look up a bit more on that though....

Sounds like BS if you ask me. You have to understand that this type of thing wouldn't fly in the consumer realm, there is no way I could imagine it could exist.


As for what Garm is saying.... The only problem I had was not the B/G, but the security protocol? I could not use... I forget what the best encryption was, because my WAP could only handle the older one.

Right now, we have WEP, WPA and WPA2 (personal or enterprise).

WEP is outdated and can be easily cracked, allowing anyone access to your network.
WPA is a little better, but not exactly bulletproof.
WPA2 is industry standard now and should be used, it's your best option security-wise.

XPSP3 and later support WPA2, and most wifi hardware (NICs, WAPs, etc.) supports at least WPA and most actually support WPA2 with a driver or firmware update, this has been true for several years.


Thanks for the links to the machines. I will have to take a look and see if I can set them up with the same channel/name/PW so I do not have to reset all the machines in the house......

Big, stupid idea. If you're still using WEP as you suggest above, you should at least upgrade the encryption to WPA2-personal, which means you'll need to reconfigure your clients as such also.

Ash
03-29-2011, 10:17 AM
I think you're confused.

2.4GHz, 3.6GHz and 5.0GHz are simply the modulated frequency that communication is occuring. 802.11 (http://en.wikipedia.org/wiki/IEEE_802.11) is the standard (protocol?) used to communicate over those frequencies. Your post implies that maybe you think the frequency and the protocol are somehow tied together?

Just like a multilingual person, a router is capable of talking in multiple standards with multiple devices at the same time without forcing everyone to talk the same language/standard. If not, someone using 802.11b would be able to hop onto your network and destroy all clients using 802.11g or 802.11n.

---


Also - Here are some examples of a respectable dual-band routers (outputting 2.4 and 5.0 simultaneously) - and mind you, I hate D-Link b/c their support and low-to-mid end products are shiet:

http://www.netgear.com/upload/flv/wndr3700landing.aspx
http://www.dlink.com/products/?pid=681

I think I may have implied or stated something about the antennae above - the # of antennae on the card affect the throughput of the connection, not the number on the WAP. Although, for some strange reason, I've noticed that WAPs with only 1 antenna seem to have lower max speeds. Could be coincidence.

Does this help, baldy?


I got the Netgear wndr3700 and it works great. Granted I have a very small house.

Ash
03-29-2011, 10:19 AM
Possibly. But I break just about anything shift, including vanilla.

Programs crash on me all the time and not because I did something radically different, just enough different that had two things running at the same time that should not have been.

Linux was a problem because the media players sucked. None would que up a list (easily, w/o having to make a playlist), so watching 10 episodes of Bleach, on the HTPC, was a PITA if you kept having to open a new one up each time.

Then not being able to reformat the drive to get the half that was partitioned for Linux was fun too. I looked online, all I got was "that should not happen".

And the DD-WRT? The signal boost was great... but, like I said, something was not jiving and it would drop every 2 minutes or so. Then reconnect. This was not a common occurance, so there was no real info on it.


Instead of being vanilla, I think I should be called Beta. I know how to bring out the Beta in things even when they are Gold.

My old router did the same thing, I noticed it was rebooting then wouldnt stop the rebooting cycle.

Ninjahedge
03-29-2011, 02:02 PM
Shift, I believe it was using WPA not WPA2.

http://www.newegg.com/Product/Product.aspx?Item=N82E16833124188

I think I had the older version of this one, I could not find any more info.... (Mine was blue?)

As for the antennae... You think I am making this up, but there is something to be said about the limit of transmissability. It may be that or simply that it is easier to tune one antenna to something slightly different than another in order to handle a seperate data stream. You COULD probably get them all to be done on eone antenna, but if it is cheaper to have two and electronically adjust them to be receiving one better than another w/o interfering with each other.....


Like I said, I will have to look up Physics/electrical engineering and such to verify why 2 antennae are needed to boost the speed.

My bet is on cost.

shifty
03-29-2011, 03:13 PM
I talked to a couple of EEs here at work just now. They're saying they think you're smoking crack and probably should refrain from making yourself look anymore of an ass at this point.

Ash
03-29-2011, 05:08 PM
Fractal antennae has made the new tech work a lot better. Not only on router's but on cell phones etc.

Electrical Noise interferance(Micro, fridge) along with the FCC(?) making sure that devices use very low powered transmitting so we dont end up frying our brains cause for unreliable connections.

Pass the pipe Ninj Ill join the party!!

Wes
03-29-2011, 05:50 PM
Like I said, I will have to look up Physics/electrical engineering and such to verify why 2 antennae are needed to boost the speed.


"802.11n uses multiple radios and antennae at endpoints, each broadcasting on the same frequency to establish multiple streams. The multiple input/multiple output (MIMO) technology splits a high data-rate stream into multiple lower rate streams and broadcasts them simultaneously over the available radios and antennae. This allows for a theoretical maximum data rate of 248 Mb/s using two streams."

=A!M=OakWind
03-29-2011, 05:54 PM
Radio waves are to long to cause cellular damage.

Bald_Yew
03-29-2011, 07:47 PM
...and for clarification, I was speaking of draft n single band routers. their radios would default to G if there was a G client on the network.

Sorry - gotta think new dualband..

Ninjahedge
03-30-2011, 07:56 AM
I talked to a couple of EEs here at work just now. They're saying they think you're smoking crack and probably should refrain from making yourself look anymore of an ass at this point.

Tell them to go F themselves.

Ninjahedge
03-30-2011, 07:59 AM
"802.11n uses multiple radios and antennae at endpoints, each broadcasting on the same frequency to establish multiple streams. The multiple input/multiple output (MIMO) technology splits a high data-rate stream into multiple lower rate streams and broadcasts them simultaneously over the available radios and antennae. This allows for a theoretical maximum data rate of 248 Mb/s using two streams."

That still does not explain why Wes.

Antennas can pick up any frequency, but there are some limits based on materials and based on how the system is wired.

It is a piece of metal, right? It should be able to go as fast as the wind and receive multiple signals all at once with no problem, right?

I know it is BS. There is a reason for using multiple antennae, but so far nobody has come up with an answer, just glib insults that some people take a bit more personally than others (hint).

Ninjahedge
03-30-2011, 08:00 AM
Fractal antennae has made the new tech work a lot better. Not only on router's but on cell phones etc.

Electrical Noise interferance(Micro, fridge) along with the FCC(?) making sure that devices use very low powered transmitting so we dont end up frying our brains cause for unreliable connections.

Pass the pipe Ninj Ill join the party!!

Sorry, I can't afford crack.

This is just baking soda and drain-o....

shifty
03-30-2011, 11:49 AM
I know it is BS. There is a reason for using multiple antennae, but so far nobody has come up with an answer, just glib insults that some people take a bit more personally than others (hint).

Wes already posted answer above, Mr. Glibbles.

Ninjahedge
03-30-2011, 12:52 PM
Wes already posted answer above, Mr. Glibbles.

No, you didn't.

If an antenna has no problem with bandwidth (it can receive as much as it wants), why do you need a seperate one in order to hook to another receiver/transmitter?

Shouldn't you be able to hook as many different things to that pole and broadcast away, so long as your frequency was far enough away to avoid any bleed/interference?

The only thing Wes's post explained was the need for two radio units, not two antennae.

Ninjahedge
03-30-2011, 12:58 PM
Wes, the only thing I do not understand is how two antennae can transmit "at the same frequency" unless they have some sort of shared overlap where one does not transmit when the other is. Kind of like saying two people can clap faster than one.

If they are on the same frequency, there would have to be some other way to differentiate them from each other or the signals would get confused/mixed....

Saboteur
03-30-2011, 03:06 PM
Tangentially related:
FCC giving out free Wireless-N routers as part of broadband test (http://www.blogtechnical.com/887/fcc-giving-out-free-wireless-n-routers-as-part-of-broadband-test.bt)

Ninjahedge
03-30-2011, 03:41 PM
tanx!

Dr. Death
04-04-2011, 09:58 PM
You use multiple antennas because each transmitter is impedance-matched to the medium (air) through its antenna. Two transmitters cannot share an antenna (and transmit at the same time.)

The two antennas cannot transmit at "exactly" the same frequency. Within the 2.4 GHz band there are about 11 subchannels that WiFi uses. Two routers (or two antennae on the same router) can't use the same subchannel or they will interfere with each other.

Receivers, on the other hand, can share an antenna and receive on multiple channels at the same time. But you need a separately tuned receiver for each channel you receive. Your cable box is a good example. It can record on one (or two) channels at the same time it's showing you a third on the TV.

Ninjahedge
04-05-2011, 09:10 AM
You use multiple antennas because each transmitter is impedance-matched to the medium (air) through its antenna. Two transmitters cannot share an antenna (and transmit at the same time.)

That is what I thought once Wes posted his info.....

Why can it only transmit one but receive multiple? Is it due to an active/passive mode? (it can listen and filter what is going through the wire and analyze it separately, but if it transmits, it will interact with any other transmission along its length?)

I know the transmission rate that an object is limited to is due to its... impedance(?), kind of its EM dynamic resistance that prevents the rate of reversal due to inherent signal response time (it can only be electromagnetically pushed and pulled so fast), but I am guessing that that is FAR less restrictive that the ability of the transmitter, or possibly the ability of the signal itself to be kept true in open atmosphere, than the physical limitations of the antenna material.....

Interesting.

BTW, those "channels". Are they really on the same wavelength, or are they only within a certain bandwidth that the FCC considers to be one frequency? If they are at the same frequency, how would you be able to tell one from the other (akin to playing the same note on an instrument in morse code, and someone else starts the same right next to them. W/o seeing them, how could you tell what each was playing/saying?)

Lastly, how is this digital signal transmitted? Is it akin to an FM transmission, or is it literally like EM morse code? Do you get a radio wave that changes in frequency, or do you get short blips? I thought that the latter was limited, but I may be wrong....


Thanks guys!

Dr. Death
04-05-2011, 04:21 PM
That is what I thought once Wes posted his info.....

Why can it only transmit one but receive multiple? Is it due to an active/passive mode? (it can listen and filter what is going through the wire and analyze it separately, but if it transmits, it will interact with any other transmission along its length?)

Transmitting is all about power transfer. To transfer maximum power, the impedance of the transmitter must match that of the transmission line. (the coax cable from the cable company to your box is a transmission line; so is the antenna/air/antenna/ interface to your wireless device from the router.) When the transmitter turns "on", its output impedance matches the cable/antenna so that it can transfer maximum power to the line. Obviously only one device at a time can do this.

Receivers are more about sensing voltage. Therefore, they are usually high impedance devices. This creates an "open circuit" at the end of the transmission line that will maximize the voltage present (an open circuit has max voltage and min current; a short circuit has min voltage and max current.) Thus it's possible to hang several high impedance receivers on the same line.


I know the transmission rate that an object is limited to is due to its... impedance(?), kind of its EM dynamic resistance that prevents the rate of reversal due to inherent signal response time (it can only be electromagnetically pushed and pulled so fast), but I am guessing that that is FAR less restrictive that the ability of the transmitter, or possibly the ability of the signal itself to be kept true in open atmosphere, than the physical limitations of the antenna material.....

Not sure what you mean here. The "speed" of any electromagnetic radio signal is limited by the speed of light in that medium. It's fastest in a vacuum (free space) and slower anywhere else.

As far as the "speed" of a WiFi signal, you are really talking about the data rate, which is limited by the channel bandwidth. When you modulate a signal, that signal varies in frequency and phase with the modulating signal (your data.) The higher the data rate, the wider the swing, and the more bandwidth the channel will occupy.


Interesting.

BTW, those "channels". Are they really on the same wavelength, or are they only within a certain bandwidth that the FCC considers to be one frequency? If they are at the same frequency, how would you be able to tell one from the other (akin to playing the same note on an instrument in morse code, and someone else starts the same right next to them. W/o seeing them, how could you tell what each was playing/saying?)

They are not at the same frequency:
http://www.radio-electronics.com/info/wireless/wi-fi/80211-channels-number-frequencies-bandwidth.php

Scroll down to the chart that shows each channel (my bad...there are 14 channels not 11 like I said, but only 11 are allowed in North America.) You will see that each channel occupies a different center frequency. Looking below that chart you will see that some channels overlap, but absent any other interfering equipment, there can be 3 non-overlapping channels at a time. These 3 channels would be what your router uses together for maximum speed. There are 5 different combinations of the three channels. The router can't use overlapping channels together or they would interfere and not work.


Lastly, how is this digital signal transmitted? Is it akin to an FM transmission, or is it literally like EM morse code? Do you get a radio wave that changes in frequency, or do you get short blips? I thought that the latter was limited, but I may be wrong....



The basic modulation technique used is quadrature phase shift keying. It's complex, but in a nutshell, it encodes 2 binary bits at a time and assigns each (4 different entities) a certain phase within the transmission carrier.

http://cnx.org/content/m10042/latest/


Thanks guys!

Jeez, how'd I get sucked into writing a textbook here? :p

Ninjahedge
04-06-2011, 08:42 AM
DD, I mean speed of reciprocation. A signal is inherently a sign wave. You need to electromagnetically vibrate the antenna in order to get it to transmit, correct?

Can you electomagnetically vibrate an antenna as fast as you want, or is there a limit to how fast you can push and pull before your sign wave starts to distort?

I know there are problems with resistance and associated heat generation, but is THAT the limiting factor, not the dynamic resistance (EM Dampening) of the material?

I know that the make the case for Fiber Optics because of some of these limitations, but I don't know if it was just EM interference (induction on neighboring wires reducing large cable efficiency) or some other factor....

Ninjahedge
04-06-2011, 08:47 AM
DD, thanks for the reply. I understand what you are saying on most of it, although the tech is a little beyond me.

It is interesting to see that they are really using multi-channel transmission for the increased data rate! I guess this ALSO means that you might stand to have more interference from your neighbors if you are pretty much using 3 channels that span most of the allowable signal bandwidth that comprises all of the channels.... When there was only one channel you could transmit/receive, there was less of a chance of overlap (I am guessing). I know, it also depends on range, but when you are (or were) living in the city.....

Thanks again for the info. It is good to understand the basic workings of what you are using!

Wes
04-06-2011, 01:14 PM
Yea, that's why FCC limits the home device can have only so much power to avoid neighbor interference. With the 2/3 antennae, the chance of interference is really great especially in the city.

There are not really much limit on how fast you can push/pull signal from our current technology. Once we get the EM spectrum, transmission material does not matter as much any more. The more important factor is more to the dimension of the material. For example, the idle "cable" for 1Ghz is a rectangular hollow tube with cross section of 1"x3/4". For regular wire or printed circuit board, for each wavelength worth of distance, you can even cut the circuit/cable, the signal still continue on. At half wavelength, you can completely block the signal from going through. That's how your microwave oven blocks microwave coming out even there are holes on it for you to see. The microwave technology is very fascinating. I think those are the few courses I enjoyed the most when i studied in college.

Ninjahedge
04-06-2011, 02:05 PM
You talking about free-end echo? (the reflected EM counters the current signal progressing, so you have to be careful.....)

I am only piecing this together from the stuff I have overheard from the EE's in the other department and other places....

I have also heard that the frequencies used have their own limitation as to the things they can pass through. That long wave signals, ala AM radio, have a better transmission through air than shorter frequencies.

So many little things involved in this!


BTW, the triple signal really does not make real-time transmission any better, does it? I remember dual signal DSL way back when. The transmission went up, but you still could not get a better connection for games. They did not sync up (I guess).

Is it the same for these dual and triple band routers?

Wes
04-06-2011, 02:22 PM
When we are in the EM area, there are lots and lots of interesting rules. You really have to study it to see all the limitation and fun stuff. I think it's a little tough to cover them all in a forum post.

Back to the router, triple signal shouldn't have much different from single signal. They operate on non-overlapping channels. Should make no different on getting a better or worst connection for games.

Some 802.11n info here http://en.wikipedia.org/wiki/IEEE_802.11n-2009

Dr. Death
04-06-2011, 07:05 PM
DD, I mean speed of reciprocation. A signal is inherently a sign wave. You need to electromagnetically vibrate the antenna in order to get it to transmit, correct?

Can you electomagnetically vibrate an antenna as fast as you want, or is there a limit to how fast you can push and pull before your sign wave starts to distort?

I know there are problems with resistance and associated heat generation, but is THAT the limiting factor, not the dynamic resistance (EM Dampening) of the material?

I know that the make the case for Fiber Optics because of some of these limitations, but I don't know if it was just EM interference (induction on neighboring wires reducing large cable efficiency) or some other factor....

You can "vibrate" an antenna as fast as you want. The design of the antenna will determine at what frequencies it will match impedance with the air and create a good transmission with no reflections. Most antennas are quarter wavelength. What this does is, at the correct frequency, when the transmitter is putting out maximum current, the antenna is putting out maximum voltage (draw a sine wave on a piece of paper starting at zero, and look at the 1/4 wavelength part--it's the peak.) This gives maximum coupling to the air. An antenna is simply an impedance matching transformer, designed to couple the signal from the transmitter to the air.

If the antenna is not matched properly to the air at the transmitting frequency, then you will get reflections. The reflections are the transmitted power being bounced back to the transmitter instead of going out over the air. If a lot of the power is reflected on a high powered transmitter, you can burn it out, because the circuits are not designed to handle the additional power.

Different frequencies travel differently over transmission lines (other than air, which seems to handle most frequencies about the same.) as the frequency goes up, the energy travels more along the skin of the wire. This is why microwave waveguide is a hollow tube. There is no energy traveling inside, it's all on the inside surface of the waveguide.

Fiber optics is used for several reasons. Number one, the higher the carrier frequency you use, the more information you can put on it. That is why FM radio can handle higher fidelity stereo, while AM cannot. The frequencies are higher. Light has a much higher frequency than RF, VHF, UHF, or microwaves. So you can put craploads of information on a single fiber channel.

Second, fiber optics is immune from electrical noise, grounding problems, etc. It's impervious to water penetration into the cable, unlike coax. For long distances, it's a better transmission medium.

Dr. Death
04-06-2011, 07:16 PM
I have also heard that the frequencies used have their own limitation as to the things they can pass through. That long wave signals, ala AM radio, have a better transmission through air than shorter frequencies.


AM signals travel farther (especially at night) because they will bounce off the ionosphere and back to earth. A higher frequency signal will simply punch through and keep going into space. All signals travel through the air about the same, but higher frequency signals don't bend or bounce well off other objects, so their transmission works best in line-of-sight systems.

The worst part about receiving FM stations in the city is not that the buildings block the signal, but that the signal bounces off everything--buildings, cars, etc, and causes "multi-path distortion." You can test this yourself when you pull up to a busy stop light. If you get a bad signal, creep the car forward and it will improve. Signals that bounce off nearby cars can interfere or reinforce the main signal, depending on if they're out of phase or in phase with it.

Dr. Death
04-06-2011, 07:20 PM
As far as gaming connections goes, it's all about lag, or delay. There is very little difference in the actual transmission speeds over the various channels (wires for Cat5 or air for WiFi.) Most of the delay will come in when you convert signals back and forth. My guess is that there will be less lag on a Cat5 connection, because of the simpler transmitting and receiving circuitry involved. If you compare your lag times on a wired vs. wireless connection, you may be able to detect a difference. However overall, it will be very small compared to all the other internet router delays between you and the server.

Ninjahedge
04-07-2011, 08:11 AM
Thanks DD.

I kinda knew about the signal bouncing and the resonant pockets/dead zones (one of the things that is very similar in audio transmission....)

Second question (Product wise) for you guys.

If I were to go for something like the WNDR3700 for a base unit, what would I need for the access points?

I know I already have a G card will have a WRT54G router no longer being used, but are there decent units that can be used at the end for maximum throughput?

(I would need connection to one laptop, an HTPC hardwired, and a media unit for the "kiddie room" TV/media box).

Thanks again!

Wes
04-07-2011, 11:42 AM
If you need to be downward compatible, it doesn't matter much which product you use since you can't run the base unit as a pure 802.11n mode with full 40 mbit bandwidth. Also, only 2 of the antennae will be used for the 802.11n and it uses the 3rd antenna for other mode.

Ninjahedge
04-07-2011, 12:58 PM
I will have to see if my wife's laptop has 'n'....

Otherwise are there any single port units that can be used as the connection point?

I know I will want to either upgrade the wireless card on my HTPC or get another wireless router to connect it and the (now broken) X-Box, but the online media center for the kids playroom is another matter.

I either get a 3 channel router to broadcast dual 'n' or I get a dual band and just make sure everything I have can receive it.....

Come to think of it, I don't think I can do the latter since my Slimserver boxes are all 'g'..... :P

Shift, that WNDR seems to be a dual band.... I was not able to find anything on the advert flyer saying whether that was dual 'n' and an additional for "guest" at 2.4/'g' or if 2 was all you got.

Any rec's on it and a good card/access point for the main unit in the living room would be helpful.

TIA!

Dr. Death
04-07-2011, 05:27 PM
You should also investigate gigabit wired, for those devices that are convenient to hard wire. You will get triple the max 802.11n speed between gigabit devices, and free up wireless bandwidth for other devices. You can install a gigabit switch on the router/WAP, and hard wire your HTPC, file server, and any fixed desktop PCs to that. They will talk at 1000 mbps, except when going on the internet or interacting with the router (to get a new IP or DNS from DHCP, for example.)

Ninjahedge
04-08-2011, 08:13 AM
Understood DD.

Setup is like this, however.

I have the gaming/main machine upstairs in the office with the server. I am thinking of eventually replacing THAT with something like a Drobo, but downloads would still require one machine to be on regardless, so I do not know how handy that would really be.

The main router from Verizon is your standard B/G/100. So you are right about that bottleneck, but the net isn't exactly tooled for faster than that anyway.

the HTPC is downstairs and one room away. I am figuring 60' strait line or about 120-140 feet sticking to the corners. The only way to get the wire over there would be running it down the holes for the heat (steam) pipes and along the walls. Plaster is not fun to try and hide the wires.

The kids room is on the same level as the HTPC, and I could probably hardwire both of them to the same point, but that would involve some crawlspace wiring under the front deck. I would like to avoid that if all I am getting is Netflix Thomas the Train episodes.....

That's about it. Just trying to figure the best way to run all of this.


Thanks again guys. I will let you know what I get, if I het. That Netgear "looks" nice (nevermind trying to be stylish like Linksys is trying to do for some reason), but when the prices are over $100, it is hard to convince myself that I need to get two for a good link.......

Advice is welcomed on that.

DD, Shift, Wes, do you have multiple router units as transmission/reception points?

Wes
04-08-2011, 02:11 PM
Yea, I used to just having 1 WiFi AP near where the FIOS comes in but on the other end of the house always have weak signal. Later I changed all of my PoE (Power over Ethernet) and WiFi hub to wired network. As the movie files get bigger (think BR Img files at 20-40GB EACH), WiFi/PoE is just not enough. I did add another WiFi access point on the other end of the house though. Just for better signal for whoever needs it. It is not a repeater. It connects to the network via a gigabit cable.

Cerwin_Vega
04-08-2011, 06:21 PM
Yay... Shifty supports the router I bought. It's awesome btw!

http://www.netgear.com/upload/flv/wndr3700landing.aspx

Ninjahedge
04-27-2011, 08:18 AM
OK, looking through, there are two D-links on sale...


The one that Yew bought (655) for $65 and the one that Shifty recommended (825) for $115.

I believe the second is a dual-band, but I am not sure about the first (there is no mention of it).

Both are tri-transmitters and Gbit LAN.

Any recommendations? One of each maybe? (The 825 for the base station at the modem and the 655 at the entertainment center? I can then use the old G for Jr's setup in the front porch with a media player (like the WD).

Then I believe everything can go WPA2 (I will have to see about the slimline servers... but if they are constantly updating firmware I do not see how they would not have a new encryption standard available by now....)

Thanks guys!

-E

shifty
04-27-2011, 10:39 AM
If it doesn't say 'dual band', it's probably not dual band, and i would not buy it.

specifically, you want 'simultaneous dual band' (or similar). you do not want hardware-switchable dual band. if you go single band, you're basically buying obsolescence, which is a bad investment. if you go hardware-switchable dual band, then you can't use half the band improvement until you upgrade all devices in your house and switch from 2.4GHz to the higher freq (5.0GHz), unless you keep two WAPs up in your house, which is a clusterf$&# that nobody should need to deal with.