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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?
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:
There may be a cheaper way for you to get the gain you need, from your existing equipment, without spending any money at all. 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. Simply make one, and then set it behind your existing router's vertical antenna... aim the parabola in the direction of your shed and place the router's antenna at the focal point of the parabola. Aim carefully, and it wouldn't be surprising for you to get 8 - 10 dB of additional gain. Hmm. I wonder. This is too good to be true. So, I will be a bit critical with you (i.e., the scientific method) just to "test" the assumption so that I can be sure I understand your position. Assuming a 9 dBd increase in the directional gain from putting a pie tin behind one of my existing router antennas, that equates to either 280 or 380 feet of range based on the calculations below. a) 9 dBd = 10^(9/10) power gain ~= 8x power gain b) 8x power gain = sqrt(8) range gain ~= 2.8X range gain c) 100 foot range * 2.8 ~= 280 foot range I'm a bit confused about the "range gain". May I ask if thta 280 foot range is the total range or the range improvement? That is, is my range with a pie tin behind the antenna 280 feet in toto; or is the range now the 100 original feet + 280 additional feet which equals 380 feet in toto? Beverly |
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 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 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:
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?
On Mon, 10 Jul 2006 18:24:27 -0400, wrote in
: On Tue, 4 Jul 2006 21:31:06 +0000 (UTC), (Geoffrey S. Mendelson) wrote: 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. True, but the ones that use the dynamic encryption can do a reasonably good job along with a firewall and router. The golden rule is "Nothing is bullet proof" Not even in the same universe -- WEP is easily cracked in minutes, little more than the Emperor's new clothes. Use WPA with a strong passphrase for any real security. One of the locals mentioned doing a bit of "war driving" around town just for curiosity. About 80 to 90% of the networks heard were unencrypted AND over half of those _still_used_ the_default_name_and_PW. Yep ... really bad ... shame on the wireless hardware companies! I use hard wired Cat5e in a gigabit network as with the amount of traffic wireless is just too slow even if it is full duplex. Wi-Fi is half duplex. -- Best regards, FAQ for Wireless Internet: http://Wireless.wikia.com John Navas FAQ for Wi-Fi: http://wireless.wikia.com/wiki/Wi-Fi Wi-Fi How To: http://wireless.wikia.com/wiki/Wi-Fi_How_To Fixes to Wi-Fi Problems: http://wireless.wikia.com/wiki/Wi-Fi_Fixes |
How to calculate increase of home wireless router range?
One of the locals mentioned doing a bit of "war driving" around town
just for curiosity. About 80 to 90% of the networks heard were unencrypted AND over half of those _still_used_ the_default_name_and_PW. Yep ... really bad ... shame on the wireless hardware companies! ======================== You probably mean 'shame on the users' who haven't got a clue. By the way it is the same situation here in the north of Scotland . Driving in Inverness you can freely access WiFi points allover town ,from commercial companies to hotels..........but not at locations where you would expect it ....like 'Starbuck' and bookshops like 'Borders' Also in California you have to pay for WiFi access at Starbuck.........must constitute a increasing part of their income,considering the number of people with laptops.....usually without a coffee.. I know ,I know ...life isn't a freebee Frank GM0CSZ / KN6WH |
How to calculate increase of home wireless router range?
Highland Ham wrote:
By the way it is the same situation here in the north of Scotland . Driving in Inverness you can freely access WiFi points allover town ,from commercial companies to hotels..........but not at locations where you would expect it ....like 'Starbuck' and bookshops like 'Borders' This will go on until the Scotish police start doing what the English do. They track traffic at the ISP level looking for "kidde porn". Once they find it, they locate the person sending or receiving the files. They have no trouble getting a warrant and come in and arrest the owner of the account and confiscate their equipment. As soon as they do this, "users" will go looking for unencrypted networks and use them, if they don't know I don't know Scotish law, but in most places the owner of the network is responsible for what is done with it. There was a case in Canada of a man found driving five miles per hour in a residential neighborhood. When the police stopped him, his pants were around his ankles and there was a laptop on his lap. Canada unlike most places has a law prohibiting using other people's internet connections without permission. Most places don't. 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, 11 Jul 2006 10:53:18 +0100, Highland Ham
wrote in : One of the locals mentioned doing a bit of "war driving" around town just for curiosity. About 80 to 90% of the networks heard were unencrypted AND over half of those _still_used_ the_default_name_and_PW. Yep ... really bad ... shame on the wireless hardware companies! ======================== You probably mean 'shame on the users' who haven't got a clue. No, I mean shame on the wireless hardware companies, as I wrote, for such a gross disservice to their customers -- it shouldn't be necessary to be an IT expert to use Wi-Fi safely. It should just work properly. Otherwise it's not ready for the market. -- Best regards, FAQ for Wireless Internet: http://Wireless.wikia.com John Navas FAQ for Wi-Fi: http://wireless.wikia.com/wiki/Wi-Fi Wi-Fi How To: http://wireless.wikia.com/wiki/Wi-Fi_How_To Fixes to Wi-Fi Problems: http://wireless.wikia.com/wiki/Wi-Fi_Fixes |
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