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How to calculate increase of home wireless router range?
Can you help me roughly CALCULATE how to increase the range of my home
Internet wireless WiFi setup to a shed 300 feet away from my house? Presently, I can walk about half the way through the wooded area to the shed with my laptop in hand before I lose the connection to the PCMCIA 802.11b,g Linksys card. Basically I need to gain 150 feet in "range". But how? At the store, I immediately become confused as I try to compare $30 USD omnidirectional antennas (D-Link ANT24-070) that boost "power" by a claimed 7 db; $50 USD directional corner antennas (Hawking HAI15SC) that claim 15 dbi (whatever a dBi is); and $150 USD 802.11N routers that claim to boost omnidirectional "range" by 4x (Linksys WRT300N). How does an omnidirectional 7 db or directional 15 dBi boost in "power" equate to range? Approximately how many decibels of (omnidirectional or directional) power do I really need to boost my WiFi range from about 150 feet to the 300 feet I need? Looking up what a decibel is (http://en.wikipedia.org/wiki/Decibel#Definition), I calculate the D-Link ANT24-070 omnidirectional antenna gives me about 5 times the power (assuming 7 db = 10^7/10 ~= 5); but does this get me the additional 150 feet of range to my shed? Spending almost twice as much money on the Hawking HAI15SC directional antenna gets me roughly 30 times the power (assuming 15 db = 10^15/10 ~= 32); but is that enough power to get me the range to my shed? Indeed, is there some way to add a Hawking 15db antenna on the receiving end to get 1,000 times the power (15 db + 15 db = 30 db = 10^30/10 ~= 1,000); but what would I hook the wire output from this receiving antenna to in the shed (I can't hook it to the pcmcia card, can I)? Given those db calculations, how do I compare the antenna options with replacing my home 802.11b,g router with the 4X range $150 USD Linksys 802.11n WRT300N router and the required $120 USD Linksys WPC300N PCMCIA card (assuming 6 db = 10^6/10)?Will this three-antenna 802.11n router be forced to drop down to 1X speeds because inside my house my kid's laptops will all be using 802.11b or 802.11g? Or can the router work on both 802.11g to one computer and on 802.11n to the other computer at the same time? I'm so confused! All I want is to make a well-informed buying decision to increase my WiFi range reliably to 300 feet to a known point. Can you help me sort out all these very confusing variable (to me anyway)? I have no training in electrical engineering; but I can google. Thank you, Beverly |
How to calculate increase of home wireless router range?
"Beverly Erlebacher" wrote in message .. . Can you help me roughly CALCULATE how to increase the range of my home Internet wireless WiFi setup to a shed 300 feet away from my house? Presently, I can walk about half the way through the wooded area to the shed with my laptop in hand before I lose the connection to the PCMCIA 802.11b,g Linksys card. Basically I need to gain 150 feet in "range". But how? At the store, I immediately become confused as I try to compare $30 USD omnidirectional antennas (D-Link ANT24-070) that boost "power" by a claimed 7 db; $50 USD directional corner antennas (Hawking HAI15SC) that claim 15 dbi (whatever a dBi is); and $150 USD 802.11N routers that claim to boost omnidirectional "range" by 4x (Linksys WRT300N). How does an omnidirectional 7 db or directional 15 dBi boost in "power" equate to range? Approximately how many decibels of (omnidirectional or directional) power do I really need to boost my WiFi range from about 150 feet to the 300 feet I need? Looking up what a decibel is (http://en.wikipedia.org/wiki/Decibel#Definition), I calculate the D-Link ANT24-070 omnidirectional antenna gives me about 5 times the power (assuming 7 db = 10^7/10 ~= 5); but does this get me the additional 150 feet of range to my shed? Spending almost twice as much money on the Hawking HAI15SC directional antenna gets me roughly 30 times the power (assuming 15 db = 10^15/10 ~= 32); but is that enough power to get me the range to my shed? Indeed, is there some way to add a Hawking 15db antenna on the receiving end to get 1,000 times the power (15 db + 15 db = 30 db = 10^30/10 ~= 1,000); but what would I hook the wire output from this receiving antenna to in the shed (I can't hook it to the pcmcia card, can I)? Given those db calculations, how do I compare the antenna options with replacing my home 802.11b,g router with the 4X range $150 USD Linksys 802.11n WRT300N router and the required $120 USD Linksys WPC300N PCMCIA card (assuming 6 db = 10^6/10)?Will this three-antenna 802.11n router be forced to drop down to 1X speeds because inside my house my kid's laptops will all be using 802.11b or 802.11g? Or can the router work on both 802.11g to one computer and on 802.11n to the other computer at the same time? I'm so confused! All I want is to make a well-informed buying decision to increase my WiFi range reliably to 300 feet to a known point. Can you help me sort out all these very confusing variable (to me anyway)? I have no training in electrical engineering; but I can google. Thank you, Beverly ========================================== Very simply - four times the transmitter power ( +6 dB ) doubles the range. Is your receiver sufficiently sensitive? Or is the received signal below the noise level? ---- Reg. |
How to calculate increase of home wireless router range?
On Tue, 04 Jul 2006 06:28:16 -0000, Dave Platt wrote:
Can you help me roughly CALCULATE how to increase the range of my home Internet wireless WiFi setup from 150 feet to a shed 300 feet away? Doubling the range requires 6 dB of additional gain from the antennas at one end or the other. Hi Dave, First thank you for taking the time to help me and anyone who read this. Second, I'm going to have to go slowly with you so I'll respond one by one. Third, does your statement that 6 dB of gain equates to 2 times the range mean that the "square root" of the power difference is my key to calculating the range? That is, is this range calculation from dB power roughly true (based on what you said)? 6 dB = 10^(6/10) ~= 4X the power, where the square root of 4X equals a doubling the range (assuming an omnidirectional antenna)? Beverly |
How to calculate increase of home wireless router range?
6 dB = 10^(6/10) ~= 4X the power, where the square root of 4X equals a
doubling the range (assuming an omnidirectional antenna)? I'm hoping I can extrapolate from the above statement to calculate the dB gain for the $150 Linksys WRT300N router which claims a 4X range improvement (so I can compare the $50 antenna's effect with that of the 802.11n router). Following your lead, the power improvement necessary for a 4X range improvement is 4^2 = 16X power gain. This 16X power gain then equates to about 12 dB (since 12 dB = 10^[12/10] ~= 16X power). So, is it safe to calculate that the claimed 4X range improvement of the Linksys WRT300N wireless broadband router can be compared to that of a 12 dB gain omnidirectional antenna? Beverly |
How to calculate increase of home wireless router range?
On Tue, 04 Jul 2006 06:28:16 -0000, Dave Platt wrote:
Can you help me roughly CALCULATE how to increase the range of my home Internet wireless WiFi setup to a shed 300 feet away from my house? dBi refers to gain relative to an "isotropic" antenna dBd refers to gain relative to a half-wave dipole dBi numbers are approximately 2 dB higher than dBd numbers, for the same actual amount of gain. Hi Dave, Oh my. I guess the Hawking marketing folks were trying to trick me by quoting a decibel number that was higher those I compared with. 15 dBi ~= 15 -2 ~= 13 dBd That makes the $50 USD 15 dBi Hawking HAI15SC Hi_Gain Antenna drop down from a gain of 32X power to only 20X power which gives me about a 4X range. 13 dBd = 10^(13/10) power ~= 20x power Assuming the square of the power is the range, I get 4X range. 20^(1/2) ~= 4X range Assuming my reliable range is 100 feet, that equates to 400 feet of range. 100 feet * 4 = 400 feet range Interestingly, for comparison purposes, that is the SAME RANGE that the much more expensive Linksys (Cisco) WRT300N router claims. Do these calculations make sense? Beverly |
How to calculate increase of home wireless router range?
On Tue, 04 Jul 2006 06:28:16 -0000, Dave Platt wrote:
Can you help me roughly CALCULATE how to increase the range of my home Internet wireless WiFi setup to a shed 300 feet away from my house? 3 dB of additional gain equates to twice the delivered power at a specific range. Because power falls off in proportion to the square of the distance, twice the power yields sqrt(2) or about 1.4 times the range, all else being equal (which it often isn't). 6 dB of additional gain is four times the delivered power at a given distance, or twice the range for the same amount of power. So that I may compare the different options available at the store to me for increasing my range, are these simplified calculations below correct? a. 3 dBd additional gain = 10^(3/10) ~= 2x the delivered power b. 2x power = 2^(1/2) effective range ~= 1.4X the range b. 6 dBd additional gain = 10^(6/10) ~= 4x the delivered power b. 4x power = 4^(1/2) effective range ~= 2X the range Can someone let me know if these calculations are correct because that helps me equate the different antennas and routers to the one measure I desire, which is effective range in the area of 400 feet. Beverly |
How to calculate increase of home wireless router range?
On Tue, 04 Jul 2006 06:28:16 -0000, Dave Platt wrote:
Approximately how many decibels of (omnidirectional or directional) power do I really need to boost my WiFi range from about 150 feet to the 300 feet I need? The _minimum_ you appear to need is 6 dB of additional gain. I'd recommend trying for 10 dB or more in order to ensure a reliable connection. May I ask WHERE that 6 dBd of gain is coming from? Is it ONLY from the "better" antenna? If that additional 6 dBd is coming from a "better" antenna, then why didn't they put that better antenna on my router in the first place? Since the antenna isn't "powerered", there is no external amplifier .... so I am a bit confused as to WHERE that power is coming from? Can you unconfusify me here? Beverly |
How to calculate increase of home wireless router range?
On Tue, 04 Jul 2006 06:28:16 -0000, Dave Platt wrote:
It's possible to fabricate a corner reflector, or (even better) a parabolic reflector, out of material as inexpensive as cardboard (or posterboard or something like that) lined with aluminum foil. Hmm. At first, I thought you were pulling my leg; but a simple google for more details gave me more homemade WiFi antenna reading than I can handle in a month. Whew. Here, for others to share, are the Yagi pringles can antennas (aka cantenna) which purport to "refocus" the WiFi signal from my router in my house to my shed 300 feet away. http://en.wikipedia.org/wiki/Cantenna http://www.oreillynet.com/cs/weblog/view/wlg/448 http://www.seattlewireless.net/index...inglesCantenna http://www.wi-fiplanet.com/reviews/article.php/3401501 http://www.turnpoint.net/wireless/has.html http://www.binarywolf.com/249/pringles_cantenna.htm http://verma.sfsu.edu/users/wireless/pringles.php http://www.seattlewireless.net/index.cgi/CookieCantenna http://webserver.computoredge.com/ed...2339/cover.htm http://www.signonsandiego.com/news/c...b13canned.html http://www.overclock.net/faqs/17669-...l-booster.html http://www.g4tv.com/screensavers/fea...i_Antenna.html http://www.netscum.com/~clapp/wireless.html http://www.flickr.com/photos/binarywolf/sets/837698/ http://linuxathome.com/files_images/cantenna.pdf Given that there are two fundamental design styles: a) Parabola b) Tube Do folks here recommend the pringles cantenna or the pie tin antenna for my 2-antenna router 802.11b,g directional application where I need to also feed the computers within the house in addition to the shed 300 feet away? Beverly |
How to calculate increase of home wireless router range?
On Tue, 04 Jul 2006 05:50:02 -0400, Rôgêr wrote:
Do folks here recommend the pringles cantenna or the pie tin antenna for my 2-antenna router 802.11b,g directional application where I need to also feed the computers within the house in addition to the shed 300 feet away? I use panel antennas almost exclusively, exceptions being some 24dbi mesh antennas for backhaul. Hi Rôgêr, After reading all the articles posted, I now understand that: a) The pringles can is hip; but it's the worst performer http://www.oreillynet.com/cs/weblog/view/wlg/448 (it's not even metal foil lined and it's too small in diameter) b) The coffee cantenna is more effective than the pringles cantenna http://www.oreillynet.com/cs/user/view/wlg/1124 c) The dish antenna is the simplest of all and almost as good http://www.freeantennas.com/projects/template http://www.freeantennas.com/projects...te2/index.html I also see, as Rod Speed so kindly noted, that the give and take is that we lose range in some directions in favor of range in the desired direction. Fair enough. My one question is a practical one. Why are there two antennas on my router anyway? Is one transmit and the other receive? Or are they both transmit and receive? Given I have TWO omnidirectional antennas on my wireless router, if I put the parabolic dish antenna on one to direct it to my shed, does that allow the OTHER antenna to radiate around the house to handle the other computers roving around the house? Beverly |
How to calculate increase of home wireless router range?
Beverly Erlebacher wrote:
Can you help me roughly CALCULATE how to increase the range of my home Internet wireless WiFi setup to a shed 300 feet away from my house? Presently, I can walk about half the way through the wooded area to the shed with my laptop in hand before I lose the connection to the PCMCIA 802.11b,g Linksys card. Basically I need to gain 150 feet in "range". But how? ==================================== Having followed today's postings on this topic , I see that there is a wooded area between your house and shed, hence there seems to be no free line of sight between the house and the shed. That's why it is difficult to calculate/predict the Gain you need to penetrate the wooded area with a 2.4 GHz signal. If you wish to use the laptop inside the shed at a fixed location it MIGHT be good enough if you install (for example)a corner reflector yagi (High Gain)antenna at both the house AND the shed. However then your laptop needs a plug-in PCMCIA WiFi tansceiver with a connection for an external antenna. One of such units is the Make: Buffalo - Air Station Turbo G ,High Power -unit which also has a built-in antenna. Note : The coaxial cable between the 2 devices and their associated antenna should be limited to only a few metres because of the high frequency being 2.4GHz Communication here is 2 way . Your laptop might receive the ( antenna amplified) signal from your router located in the house ,but that does not mean the router will receive the signal from the laptop without additional facilities at the laptop. Again , because of the probably partly obstructed path (wooded area) it is difficult making any sensible calculations. Frank GM0CSZ / KN6WH |
How to calculate increase of home wireless router range?
"Highland Ham" wrote in message
... Having followed today's postings on this topic , I see that there is a wooded area between your house and shed, hence there seems to be no free line of sight between the house and the shed. That's why it is difficult to calculate/predict the Gain you need to penetrate the wooded area with a 2.4 GHz signal. YES - exactly. I have been able to go laptop to laptop almost a mile with normal PCMCIA cards, using patch antennas. (Well - normal cards modified to bring out the signal to the antenna.) These antennas can be astonishingly directional. Indeed, at 2.4 MHz, it is pretty easy to get antennas with amazing amounts of gain. This translates into VERY CAREFUL aiming of the antenna. Also keep in mind that at 2.4 GHz, RG-58 ain't gonna cut it. Most of what you put in to one end of any normal coax will be sucked up by the coax and won't make it out the other end. You need to use cable appropriate to the frequency. With a wooded area, not only is it very difficult to calculate, but tiny differences in the positioning of the two ends is going to make a huge difference, as is summer to winter. Even a windy day is going to change things. Because of the small size, it can be pretty simple to build a yagi for wireless. Yagis won' t have the gain of some of the other types of antennas, but at the same time, they won't be nearly as critical. Depending on your situation, you may find a directional antenna a better choice than more power. Lots of people driving by like to "borrow" your wireless, and I personally don't like the idea of strangers roaming my LAN, even if they aren't typical crackers. (Seems to me that salesmen are the most common intruders. They have learned that they can find a wireless connection almost anywhere). I find getting coverage into the back yard, while NOT getting coverage well into the street is a bit of a challenge. Yes, I use encryption and MAC filtering, but I'd still rather not have lots of wardrivers trying to break in. ... |
How to calculate increase of home wireless router range?
xpyttl wrote:
I have been able to go laptop to laptop almost a mile with normal PCMCIA cards, using patch antennas. (Well - normal cards modified to bring out the signal to the antenna.) These antennas can be astonishingly directional. Indeed, at 2.4 MHz, it is pretty easy to get antennas with amazing amounts of gain. There are restrictions on the RADIATED power, transmitter output power, etc of unlicensed 2.4gHz transmitters, such as WiFi. You should check them out. They vary from country to country. If you have a ham license, then you can use 2.4gHz for data transmission, but then you are restricted in transmission mode, encryption and data content. For example, the infamous Pringles can antenna was developed in the U.S. by an FBI agent in the course of an investigation. It's use as a WiFi transmission antenna is illegal in many places. The well pubicised long distance link in Egypt was illegal. Here in Israel we are limited to 100mW EIRP for civilian useage, except for ham satellite operations which are limited to 25w. BTW, there are limitations in the U.S. too, I just don't know them. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM IL Voice: (07)-7424-1667 IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838 Visit my 'blog at http://geoffstechno.livejournal.com/ |
How to calculate increase of home wireless router range?
On Tue, 4 Jul 2006 11:03:49 -0400, Peter Pan wrote:
Can you help me roughly CALCULATE how to increase the range of my home Internet wireless WiFi setup to a shed 300 feet away .... I Had a linksys WRT54G in the house attached to my sat, and used one of the 4 router outputs to daisy chain one to the wan input of another WRT54G (same ssid) and a semi-directional antenna pointed towards the garage about 500ft away, Hi Peter Pan, Oh my! Is "wireless" daisy chaining workable? Is it that easy? I did not think I could just daisy chain multiple routers! Are you sure? (My shed has no power but I think I could run an extension cord into it if that would make things workable.) Would I just set the second Linksys router (which, amazingly, has it's own wikipedia entry at http://en.wikipedia.org/wiki/WRT54G) in the shed on the same channel (SSID=12, name = default) as the first router in the house? That is, could I put one linksys WRT54G in the house (perhaps with one antenna replaced with a 7 dBd higher-gain directional antenna); and then put the other Linksys WRT54G in the shed 300 feet away (perhaps with one of it's antennas replaced with a similar 7 dBd directional antenna)? Or, is it best to hardwire with cat5 the first router downstairs in the house to the second router, say upstairs in the attic window pointing the antenna toward the shed? I didn't even know that two routers could be daisy chained. That might solve my dilemma. Can someone confirm that two routers could be daisy chained either by wire cat5 cable or by wireless signals as long as they use the same SSID channel and network name? That solution seems to easy to be true ... Beverly |
How to calculate increase of home wireless router range?
On Tue, 04 Jul 2006 09:07:39 -0500, lid wrote:
Here is an easy way to hack your $60 wireless router into a $600 router (they use Linksys as the example): Wow. I've never "modified" a router before but that is interesting that one can increase the $75 Linksys WRT54G router (http://en.wikipedia.org/wiki/WRT54G) RF output from 28 millwatts up to 251 milliwatts (http://tinyurl.com/lpk7w). Being true to the original intent of this thread, how do I CALCULATE what that does to my range? Is this 9 dBd calculation of the modification roughly correct? a) Power gain = Power2/Power1 = 251/28 milliwatts = 9x power gain b) Range gain = sqrt(Power gain) = sqrt(9) = 3X range gain c) Range = original range * range gain = 100 feet * 3 = 300 feet Beverly |
How to calculate increase of home wireless router range?
On Tue, 04 Jul 2006 11:48:12 +0100, Highland Ham wrote:
Beverly Erlebacher wrote: Can you help me roughly CALCULATE how to increase the range of my home Internet wireless WiFi setup to a shed 300 feet away from my house? Presently, I can walk about half the way through the wooded area to the shed with my laptop in hand before I lose the connection to the PCMCIA 802.11b,g Linksys card. Basically I need to gain 150 feet in "range". But how? ================================================== == Having followed today's postings on this topic , I see that there is a wooded area between your house and shed, hence there seems to be no free line of sight between the house and the shed. That's why it is difficult to calculate/predict the Gain you need to penetrate the wooded area with a 2.4 GHz signal. If you wish to use the laptop inside the shed at a fixed location it MIGHT be good enough if you install a corner reflector yagi (High Gain)antenna at both the house AND the shed. However then your laptop needs a plug-in PCMCIA WiFi tansceiver with a connection for an external antenna. One of such units is the Make: Buffalo - Air Station Turbo G ,High Power -unit which also has a built-in antenna. Note : The coaxial cable between the 2 devices and their associated antenna should be limited to only a few metres because of the high frequency being 2.4GHz Communication here is 2 way . Your laptop might receive the ( antenna amplified) signal from your router located in the house ,but that does not mean the router will receive the signal from the laptop without additional facilities at the laptop. Again , because of the probably partly obstructed path (wooded area) it is difficult making any sensible calculations. Frank GM0CSZ / KN6WH Hi Highland Ham, I see there are multiple solutions. Probably on the end of my list is adding a wire to the laptop because then it wouldn't be wireless. Still, it's an intriguing idea (I never knew laptops could have fixed antenna's connected to them by wire). If I do use two antennas, does that "add" the gain? a) Antenna 1 transmits with a directional gain of, say 7 dBd b) Antenna 2 receives with a directional gain of, say 7 dBd c) Does that get me a 14 dBd overall gain? Beverly |
How to calculate increase of home wireless router range?
On Tue, 04 Jul 2006 06:11:27 -0700, Dan Richardsonk6mhe wrote:
If your goal is to increase your range then add an extender (hams would prefer to call them repeaters). Oh my. The seemingly perfect option. I had come across the concept of wireless "repeaters" in my initial googling before I went to the store, e.g., in this Microsoft "how to increase range" article http://www.microsoft.com/athome/more...elesstips.mspx and in this "Extending WLAN Range" article http://www.wi-fiplanet.com/tutorials...le.php/1571601 The repeater most often recommended was the "Linksys Wireless-G Range Expander WRE54G". However, I can't find that 802.11b,g WiFi repeater (aka range expander or extender) anywhere in the local stores. The salesperson who sold me the $300 USD 802.11n router and PCMCIA card combination said they didn't work so they dropped it. This solution seems to be the most elegant of all (but someone else suggested just using a second router). Can someone unconfusify the situation? Is placing a repeater (on the same SSID) in the shed really the same as adding a second router instead? Beverly |
How to calculate increase of home wireless router range?
On Tue, 04 Jul 2006 08:17:19 -0700, David wrote:
A "range extender" or "repeater" will cut the speed in half. Hi David, Interesting this speed difference. I'm worried about RANGE and all of a sudden other factors come into play! Thank you for enlightening me. I know more now than I ever did from you wonderful guys! As I noted to someone else just now, I DID try to find the "Linksys Wireless-G Range Expander WRE54G" WiFi repeater in the local stores but they did not exist in any of the three stores I checked. Also, some of the articles talk about an "access point" (http://www.wi-fiplanet.com/tutorials...e.php/1571601). Can someone tell me what part of my setup I would call the "access point"? Beverly |
How to calculate increase of home wireless router range?
On Tue, 04 Jul 2006 17:57:22 GMT, stephen wrote:
but - you mentioned you could run power out to your shed. Why not plumb it in for power and networking? then you can add a separate access point there and avoid antennae, gain, loss through leaves and the rest. Hi Stephen, I'm confused about this "access point" thing. Is that the same as a "router"? Is it as simple as buying a second router (routers are familiar to me) and just hooking that second router to the first router by cable and that would extend my range by the distance of the cable connecting the two routers? This is a key confusion point for me! Beverly |
How to calculate increase of home wireless router range?
Beverly Erlebacher wrote:
On Tue, 04 Jul 2006 08:17:19 -0700, David wrote: A "range extender" or "repeater" will cut the speed in half. Hi David, Interesting this speed difference. I'm worried about RANGE and all of a sudden other factors come into play! Thank you for enlightening me. I know more now than I ever did from you wonderful guys! As I noted to someone else just now, I DID try to find the "Linksys Wireless-G Range Expander WRE54G" WiFi repeater in the local stores but they did not exist in any of the three stores I checked. Also, some of the articles talk about an "access point" (http://www.wi-fiplanet.com/tutorials...e.php/1571601). Can someone tell me what part of my setup I would call the "access point"? The wireless part. |
How to calculate increase of home wireless router range?
Beverly Erlebacher wrote:
On Tue, 04 Jul 2006 05:50:02 -0400, Rôgêr wrote: Do folks here recommend the pringles cantenna or the pie tin antenna for my 2-antenna router 802.11b,g directional application where I need to also feed the computers within the house in addition to the shed 300 feet away? I use panel antennas almost exclusively, exceptions being some 24dbi mesh antennas for backhaul. Hi Rôgêr, After reading all the articles posted, I now understand that: a) The pringles can is hip; but it's the worst performer http://www.oreillynet.com/cs/weblog/view/wlg/448 (it's not even metal foil lined and it's too small in diameter) b) The coffee cantenna is more effective than the pringles cantenna http://www.oreillynet.com/cs/user/view/wlg/1124 c) The dish antenna is the simplest of all and almost as good http://www.freeantennas.com/projects/template http://www.freeantennas.com/projects...te2/index.html I also see, as Rod Speed so kindly noted, that the give and take is that we lose range in some directions in favor of range in the desired direction. Fair enough. My one question is a practical one. Why are there two antennas on my router anyway? That gives a more reliable coverage than with one. Is one transmit and the other receive? Or are they both transmit and receive? They're normally both transmit and receive. Given I have TWO omnidirectional antennas on my wireless router, if I put the parabolic dish antenna on one to direct it to my shed, does that allow the OTHER antenna to radiate around the house to handle the other computers roving around the house? Yes. |
How to calculate increase of home wireless router range?
"Geoffrey S. Mendelson" wrote in message
... If you have a ham license, then you can use 2.4gHz for data transmission, but then you are restricted in transmission mode, encryption and data content. And wireless channels, as well. Some of the channels are outside the U.S. ham bands. Since this is an amateur radio newsgroup, I made the (possibly rash) assumption that OP was aware of these limitations. For amateurs in the U.S., the main issue is encryption. Few of us can afford to get anywhere near the power limits at these frequencies! ... |
How to calculate increase of home wireless router range?
On Tue, 4 Jul 2006 08:30:46 -0400, xpyttl wrote:
.... Indeed, at 2.4 MHz, it is pretty easy to get antennas with amazing amounts of gain. ...... Sigh... If only that were true! HI!HI! Jonesy -- Marvin L Jones | jonz | W3DHJ | linux 38.24N 104.55W | @ config.com | Jonesy | OS/2 *** Killfiling google posts: http//jonz.net/ng.htm |
How to calculate increase of home wireless router range?
Beverly Erlebacher wrote:
I'm confused about this "access point" thing. An access point is a device with an ethernet port on one side and a wifi port on the other. In technical terms it would be called a "bridge". It "bridges" two seperate network segments, although in this case they use different topologies (100Base-T and WiFi). Is that the same as a "router"? The usual WiFi router consists of a four port ethernet hub (LAN ports), a seperate single ethernet port (WAN port) and a WiFi access point. It is set up to "route" between the single (aka WAN) port and the other two ports, the LAN and WiFi. Most of what it does for routing is NAT (network address translation) and some sort of IP tunneling. If you ignore the WAN port and just use the LAN ports, you have a four port hub and an access point. Is it as simple as buying a second router (routers are familiar to me) and just hooking that second router to the first router by cable and that would extend my range by the distance of the cable connecting the two routers? Yes. Just make sure to use the LAN ports. It would be best to use different channels. Most WiFi clients are smart enough to use the channel that is the strongest if they have access points on more than one with the same SSID. Make sure to use encryption. Encryption is NOT to keep your data safe, nothing can do that. If someone is intent on accessing your network, WEP encryption will not keep them out. What it is for is to convince the guy driving down the street looking for an open network to send out SPAM, or "share" kiddie porn, to drive on. Unfortunately, most users don't even change the SSID of their network, let alone set an encryption key. Having tuned in late, if you want to have an open network, look up PublicIP. It's a "live cd" that runs on a PII or better (x86) computer and provides all the functions you need to offer a secure and safe open network. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM IL Voice: (07)-7424-1667 IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838 Visit my 'blog at http://geoffstechno.livejournal.com/ |
How to calculate increase of home wireless router range?
Rod Speed wrote:
Is one transmit and the other receive? Or are they both transmit and receive? They're normally both transmit and receive. That's a shame. Here in Israel we are limited to 100mw EIRP, which severly limits the transmit antenna. There is NO limitation on the receive antenna. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM IL Voice: (07)-7424-1667 IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838 Visit my 'blog at http://geoffstechno.livejournal.com/ |
How to calculate increase of home wireless router range?
Geoffrey S. Mendelson wrote
Rod Speed wrote Is one transmit and the other receive? Or are they both transmit and receive? They're normally both transmit and receive. That's a shame. Here in Israel we are limited to 100mw EIRP, which severly limits the transmit antenna. There is NO limitation on the receive antenna. A receive antenna has no EIRP, it doesnt radiate any real power. |
How to calculate increase of home wireless router range?
hehe -- getting gain at the antenna isn't such a big deal ... getting the
goo TO the antenna is a whole 'nuther can of worms. It's pretty easy to come up with 10 dB of gain and 20 dB of feedline loss! Of course, for WiFi, we're often interested in gain AND omnidirectional -- that is something of a challenge. ... "Allodoxaphobia" wrote in message ... On Tue, 4 Jul 2006 08:30:46 -0400, xpyttl wrote: ... Indeed, at 2.4 MHz, it is pretty easy to get antennas with amazing amounts of gain. ...... Sigh... If only that were true! HI!HI! Jonesy -- Marvin L Jones | jonz | W3DHJ | linux 38.24N 104.55W | @ config.com | Jonesy | OS/2 *** Killfiling google posts: http//jonz.net/ng.htm |
How to calculate increase of home wireless router range?
xpyttl wrote:
hehe -- getting gain at the antenna isn't such a big deal ... getting the goo TO the antenna is a whole 'nuther can of worms. It's pretty easy to come up with 10 dB of gain and 20 dB of feedline loss! Of course, for WiFi, we're often interested in gain AND omnidirectional -- that is something of a challenge. POE! POE! POE! (Power over ethernet). Put the access point at the antenna, run a cat-5 cable (4 twisted pairs) to it. Four get used for the network connection, 4 get used for DC. Not only does it work well, but CAT-5 wire is cheap, 2.4gHz low loss coax is not. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM IL Voice: (07)-7424-1667 IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838 Visit my 'blog at http://geoffstechno.livejournal.com/ |
How to calculate increase of home wireless router range?
Rod Speed wrote:
Geoffrey S. Mendelson wrote Rod Speed wrote Is one transmit and the other receive? Or are they both transmit and receive? They're normally both transmit and receive. That's a shame. Here in Israel we are limited to 100mw EIRP, which severly limits the transmit antenna. There is NO limitation on the receive antenna. A receive antenna has no EIRP, it doesnt radiate any real power. Actually, when properly matched, it radiates half the received power. |
How to calculate increase of home wireless router range?
"John - KD5YI" wrote in message news:XLQrg.2896$bd4.372@trnddc01...
Rod Speed wrote: A receive antenna has no EIRP, it doesnt radiate any real power. Actually, when properly matched, it radiates half the received power. How do you get that? If the receiver input impedance is matched to the antenna, all the received power is absorbed. There is no reflection. There is no radiation. If the receiver matching is for optimal noise figure, there may be some reflection and reradiation, but there's nothing pinning it to be half the received power. Don |
How to calculate increase of home wireless router range?
Don K wrote:
"John - KD5YI" wrote in message news:XLQrg.2896$bd4.372@trnddc01... Rod Speed wrote: A receive antenna has no EIRP, it doesnt radiate any real power. Actually, when properly matched, it radiates half the received power. How do you get that? If the receiver input impedance is matched to the antenna, all the received power is absorbed. There is no reflection. There is no radiation. If the receiver matching is for optimal noise figure, there may be some reflection and reradiation, but there's nothing pinning it to be half the received power. John is correct. A receiving antenna, when matched, reradiates half the power it receives. An impinging field induces current in the antenna. This causes radiation, just like the current in a transmitting antenna. As it turns out, when the antenna is matched, the amount of power radiated equals the amount of power delivered to the load, and that's the best you can do. If you'd like a more in-depth and mathematical explanation, you can find it in any antenna text, often discussed as "scattering". If a receiving antenna did absorb all the impinging power, it would be a lot easier to make a shield or a stealth aircraft. Roy Lewallen, W7EL |
How to calculate increase of home wireless router range?
John - KD5YI wrote:
Rod Speed wrote: Geoffrey S. Mendelson wrote Rod Speed wrote Is one transmit and the other receive? Or are they both transmit and receive? They're normally both transmit and receive. That's a shame. Here in Israel we are limited to 100mw EIRP, which severly limits the transmit antenna. There is NO limitation on the receive antenna. A receive antenna has no EIRP, it doesnt radiate any real power. Actually, when properly matched, it radiates half the received power. Wrong. |
How to calculate increase of home wireless router range?
Roy Lewallen wrote
Don K wrote John - KD5YI wrote Rod Speed wrote A receive antenna has no EIRP, it doesnt radiate any real power. Actually, when properly matched, it radiates half the received power. How do you get that? If the receiver input impedance is matched to the antenna, all the received power is absorbed. There is no reflection. There is no radiation. If the receiver matching is for optimal noise figure, there may be some reflection and reradiation, but there's nothing pinning it to be half the received power. John is correct. Nope. A receiving antenna, when matched, reradiates half the power it receives. Yes but that ISNT ANY REAL POWER in the EIRP restriction sense. An impinging field induces current in the antenna. This causes radiation, just like the current in a transmitting antenna. As it turns out, when the antenna is matched, the amount of power radiated equals the amount of power delivered to the load, and that's the best you can do. Yes but that ISNT ANY REAL POWER in the EIRP restriction sense. If you'd like a more in-depth and mathematical explanation, you can find it in any antenna text, often discussed as "scattering". Not relevant to the original point, any effect on the EIRP restriction. If a receiving antenna did absorb all the impinging power, it would be a lot easier to make a shield or a stealth aircraft. Not relevant to the original point, any effect on the EIRP restriction. |
How to calculate increase of home wireless router range?
Rod Speed wrote:
Roy Lewallen wrote Don K wrote John - KD5YI wrote Rod Speed wrote A receive antenna has no EIRP, it doesnt radiate any real power. Actually, when properly matched, it radiates half the received power. How do you get that? If the receiver input impedance is matched to the antenna, all the received power is absorbed. There is no reflection. There is no radiation. If the receiver matching is for optimal noise figure, there may be some reflection and reradiation, but there's nothing pinning it to be half the received power. John is correct. Nope. A receiving antenna, when matched, reradiates half the power it receives. Yes but that ISNT ANY REAL POWER in the EIRP restriction sense. An impinging field induces current in the antenna. This causes radiation, just like the current in a transmitting antenna. As it turns out, when the antenna is matched, the amount of power radiated equals the amount of power delivered to the load, and that's the best you can do. Yes but that ISNT ANY REAL POWER in the EIRP restriction sense. If you'd like a more in-depth and mathematical explanation, you can find it in any antenna text, often discussed as "scattering". Not relevant to the original point, any effect on the EIRP restriction. If a receiving antenna did absorb all the impinging power, it would be a lot easier to make a shield or a stealth aircraft. Not relevant to the original point, any effect on the EIRP restriction. Always amazinmg how when some people are proven wrong, the revert to the "Is NOT, IS NOT," type of argument used by small children, then when that doesn't work, the argument becomes irrelevant. Rod, I suggest you LEARN something from your intellectual and technical betters BEFORE you show the world your ignorance. John |
How to calculate increase of home wireless router range?
Rod Speed wrote:
Roy Lewallen wrote Don K wrote John - KD5YI wrote Rod Speed wrote A receive antenna has no EIRP, it doesnt radiate any real power. Actually, when properly matched, it radiates half the received power. How do you get that? If the receiver input impedance is matched to the antenna, all the received power is absorbed. There is no reflection. There is no radiation. If the receiver matching is for optimal noise figure, there may be some reflection and reradiation, but there's nothing pinning it to be half the received power. John is correct. Nope. A receiving antenna, when matched, reradiates half the power it receives. Yes but that ISNT ANY REAL POWER in the EIRP restriction sense. An impinging field induces current in the antenna. This causes radiation, just like the current in a transmitting antenna. As it turns out, when the antenna is matched, the amount of power radiated equals the amount of power delivered to the load, and that's the best you can do. Yes but that ISNT ANY REAL POWER in the EIRP restriction sense. If you'd like a more in-depth and mathematical explanation, you can find it in any antenna text, often discussed as "scattering". Not relevant to the original point, any effect on the EIRP restriction. If a receiving antenna did absorb all the impinging power, it would be a lot easier to make a shield or a stealth aircraft. Not relevant to the original point, any effect on the EIRP restriction. Always amazinmg how when some people are proven wrong, the revert to the "Is NOT, IS NOT," type of argument used by small children, then when that doesn't work, the argument becomes irrelevant. Rod, I suggest you LEARN something from your intellectual and technical betters BEFORE you show the world your ignorance. John |
How to calculate increase of home wireless router range?
Rod Speed wrote:
Roy Lewallen wrote . . . A receiving antenna, when matched, reradiates half the power it receives. Yes but that ISNT ANY REAL POWER in the EIRP restriction sense. . . . It's real power, but that power all comes from the impinging field; it's not contributing any new power. So you're right that the EIRP restriction doesn't apply. The receive antenna reduces the amount of power in the field by the amount delivered to the antenna's termination, plus any losses along the way. The intent of the EIRP restriction is to limit the amount of field strength added by a transmitter. Roy Lewallen, W7EL |
How to calculate increase of home wireless router range?
John L. Sielke wrote:
Rod Speed wrote: Roy Lewallen wrote Don K wrote John - KD5YI wrote Rod Speed wrote A receive antenna has no EIRP, it doesnt radiate any real power. Actually, when properly matched, it radiates half the received power. How do you get that? If the receiver input impedance is matched to the antenna, all the received power is absorbed. There is no reflection. There is no radiation. If the receiver matching is for optimal noise figure, there may be some reflection and reradiation, but there's nothing pinning it to be half the received power. John is correct. Nope. A receiving antenna, when matched, reradiates half the power it receives. Yes but that ISNT ANY REAL POWER in the EIRP restriction sense. An impinging field induces current in the antenna. This causes radiation, just like the current in a transmitting antenna. As it turns out, when the antenna is matched, the amount of power radiated equals the amount of power delivered to the load, and that's the best you can do. Yes but that ISNT ANY REAL POWER in the EIRP restriction sense. If you'd like a more in-depth and mathematical explanation, you can find it in any antenna text, often discussed as "scattering". Not relevant to the original point, any effect on the EIRP restriction. If a receiving antenna did absorb all the impinging power, it would be a lot easier to make a shield or a stealth aircraft. Not relevant to the original point, any effect on the EIRP restriction. Always amazinmg how when some people are proven wrong, the revert to the "Is NOT, IS NOT," type of argument used by small children, then when that doesn't work, the argument becomes irrelevant. Never ever could bull**** its way out of a wet paper bag. Rod, I suggest you LEARN something from your intellectual and technical betters BEFORE you show the world your ignorance. Never ever could bull**** its way out of a wet paper bag. While your original was technically correct, its completely irrelevant to what was actually being discussed, WHETHER THE RECEIVE ANTENNA EVER RADIATES ENOUGH TO BE RELEVANT TO THE EIRP RESTRICTION. |
How to calculate increase of home wireless router range?
Roy Lewallen wrote:
Rod Speed wrote: Roy Lewallen wrote . . . A receiving antenna, when matched, reradiates half the power it receives. Yes but that ISNT ANY REAL POWER in the EIRP restriction sense. It's real power, Yes, BUT NOT IN THE EIRP RESTRICTION SENSE. but that power all comes from the impinging field; it's not contributing any new power. So you're right that the EIRP restriction doesn't apply. And that is what was being discussed when John made such a spectacular fool of himself mindlessly rabbiting on about what is no news to anyone with a clue about receiving antennas. The receive antenna reduces the amount of power in the field by the amount delivered to the antenna's termination, plus any losses along the way. The intent of the EIRP restriction is to limit the amount of field strength added by a transmitter. Duh. So John was mindlessly rabbiting on about a complete irrelevancy WHEN THE EIRP RESTRICTION WAS BEING DISCUSSED. |
How to calculate increase of home wireless router range?
On Sun, 9 Jul 2006 07:12:11 +1000, in alt.internet.wireless , "Rod
Speed" wrote: John L. Sielke wrote: Always amazinmg how when some people are proven wrong, the revert to the "Is NOT, IS NOT," type of argument used by small children, then when that doesn't work, the argument becomes irrelevant. Never ever could bull**** its way out of a wet paper bag. Rod, I suggest you LEARN something from your intellectual and technical betters BEFORE you show the world your ignorance. Never ever could bull**** its way out of a wet paper bag. While your original was technically correct, its completely irrelevant to what was actually being discussed, WHETHER THE RECEIVE ANTENNA EVER RADIATES ENOUGH TO BE RELEVANT TO THE EIRP RESTRICTION. I've not been following this thread, but I can tell you straight off, I am significantly more inclined to believe the guys who are not shouting and hurling abuse. Make of that what you will, but my suggestion is to counter with rational argument backed up by references and facts, rather than insults and obscenities. -- Mark McIntyre |
How to calculate increase of home wireless router range?
Mark McIntyre wrote
Rod Speed wrote John L. Sielke wrote Always amazinmg how when some people are proven wrong, the revert to the "Is NOT, IS NOT," type of argument used by small children, then when that doesn't work, the argument becomes irrelevant. Never ever could bull**** its way out of a wet paper bag. Rod, I suggest you LEARN something from your intellectual and technical betters BEFORE you show the world your ignorance. Never ever could bull**** its way out of a wet paper bag. While your original was technically correct, its completely irrelevant to what was actually being discussed, WHETHER THE RECEIVE ANTENNA EVER RADIATES ENOUGH TO BE RELEVANT TO THE EIRP RESTRICTION. I've not been following this thread, but I can tell you straight off, I am significantly more inclined to believe the guys who are not shouting and hurling abuse. You have always been, and always will be, completely and utterly irrelevant. What you may or may not be inclined to believe in spades. Anyone with a clue considers the facts, not the style stuff, ****wit. Make of that what you will, I flush it where it belongs. but my suggestion is to counter with rational argument backed up by references and facts, Dont need 'references' on that basic fact that even when the receiving antenna does reradiate about half of what it receives, THAT IS COMPLETELY IRRELEVANT TO THE LEGISLATED ERIP LEVEL. rather than insults and obscenities. I suggest you take your stupid suggestion and shove it up your arse, where it belongs. |
How to calculate increase of home wireless router range?
"Roy Lewallen" wrote in message ...
Don K wrote: "John - KD5YI" wrote in message news:XLQrg.2896$bd4.372@trnddc01... Rod Speed wrote: A receive antenna has no EIRP, it doesnt radiate any real power. Actually, when properly matched, it radiates half the received power. How do you get that? If the receiver input impedance is matched to the antenna, all the received power is absorbed. There is no reflection. There is no radiation. If the receiver matching is for optimal noise figure, there may be some reflection and reradiation, but there's nothing pinning it to be half the received power. John is correct. A receiving antenna, when matched, reradiates half the power it receives. An impinging field induces current in the antenna. This causes radiation, just like the current in a transmitting antenna. As it turns out, when the antenna is matched, the amount of power radiated equals the amount of power delivered to the load, and that's the best you can do. If you'd like a more in-depth and mathematical explanation, you can find it in any antenna text, often discussed as "scattering". If a receiving antenna did absorb all the impinging power, it would be a lot easier to make a shield or a stealth aircraft. Roy Lewallen, W7EL Maybe to some extent, it's a matter of nit-picking over what "received power" means. You can think of an antenna as having an effective aperture size over which it captures all the energy crossing that cross-sectional area. To me it's logical to think of "received power" as the power that actually gets scooped up and delivered. Effective aperture increases with antenna gain. Obviously something like a dipole has a relatively small effective aperture. But the effective aperture of a high-gain horn antenna for instance, will approach its actual physical cross-sectional area. For instance, look at Figure 13 in this pdf. http://www.coe.montana.edu/ee/rwolff...WBAntennas.pdf Don |
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