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Wifi module Buiying -Reffreance regarding

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Advanced Member level 5
Jan 7, 2010
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Hi experts, My friend has a Wifi enalbled modem whose house is about 300 metere (having obstacle like trees in the line of sight ) away from me. I want to share
the net connection with him . But i havent any Wifi enabled devices such as Laptops ,Please suggest me to buy a wifi module .Can i connect ? please help me .thanks

A general rule of thumb in home networking says that 802.11b and 802.11g WAPs and routers support a range of up to 150 feet (46 m) indoors and 300 feet (92 m) outdoors. Another rule of thumb holds that the effective range of 802.11a is approximately one-third that of 802.11b/g. Obstructions in home such as brick walls and metal frames or siding greatly can reduce the range of a Wi-Fi LAN by 25% or more.

So it is not possible to share a wifi connection from 300 metres. It's possible to extend a Wi-Fi LAN to much longer distances by chaining together multiple wireless access points or routers. I think that is not a good option in your case.

You need a wifi hardware to connect. USB wifi hardware are available in market starting from 1000 Rupees.
Please help me how can i share the net connection by using any modules like Wifi ,RF module etc

To cover 300 meters is too much to ask of normal wifi equipment. The only chance it could work is if you use a directional antenna at each end. I see such equipment is available per an internet search.

So if you're determined to try...

Your best chance is to use the recent 802.11n specification. It has the best distance operation.

Up to 240 meters according to:

IEEE 802.11 - Wikipedia, the free encyclopedia

If your friend's wifi does not operate with 802.11n then you must obtain a card which is able to use the networking specification used by your friend's wireless device. Years ago it was common to see 802.11b. Then more recently 802.11g.

Your wifi card must fit your computer slot. The designations available:

mini PCI (in types I or II or III)
PCI-e (express)
mini PCIe (mini for laptops)
PCM-CIA (mini for laptops)

The above types are not compatible in size. But check because maybe PCIe can take the place of PCIx.

You should choose a card with the most sensitive antenna. In fact you should find a directional antenna, or make your own. It has to be optimized for the wifi frequency. Normally 2.4 Ghz and/ or 5 Ghz.

Make sure the card is compatible with your operating system.

You cannot hope for high speed (54 mbps is the fastest in typical home networks). Your radio connection will probably be weak. This causes a link to drop to a slower speed (1 or 2 mbps).

To make a wifi connection at all, you'll need good antennas. Consider mounting them in a second story window. You'll need to aim them directly at each other. Avoid getting tree trunks in the line of sight.
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Thanks BradtheRad ,please give me any link to buy the Wifi card that you are above said .(i think my and my friends line of site's distance within 240 meters ).i am from india ,what is the average price

The maximum distance covered by 802.11n is 250 metres. As there are lots of obstruction in the path it will be reduced a lot. Also if consider best case it will not cover 300 metres. I think you should take your own internet connection that would be better for you and cost effective. BSNL (in INDIA) provides broad band connection at very less price. They also provide you a modem. Check out BSNL website for charge in your area. BSNL also provide broad band connection at cheaper rates for rural areas in India.

I purchased two wireless networking cards on Ebay.

One was for my desktop Macintosh. PCI type. 802.11b/g. Made in China I think. Cost $18.

The other was for my Compaq laptop. A used Intel brand, miniature PCM-CIA. 802.11b/g. Cost $7. It didn't come with an antenna. I managed to make my own antenna from a length of vinyl-insulated wire. I wrangled the end into the tiny round antenna jack on the card.

Both my wireless cards are easy to use now. However I had to get the initial settings right. That took several hours of testing and powering down and restarting. Also had to reset my wireless network modem a few times.

Your OP implies you have a desktop computer. You have to find out for certain what size slots your motherboard has.

Was your computer made since 2003? PCIx and PCIe were added to the choice around then for desktop computers.

Either you must examine the manufacturer's information regarding your computer, or else you'll have to open it up and compare the slots with measurements and notch spacings and photos of the various types of slots. 32-bit versus 64-bit can make a difference. Speed can make a difference.

As to what 802.11 specification. The chief suffix letters (starting with the oldest) are B and G and N.
802.11b cannot operate as well as 802.11g.
802.11g cannot operate as well as 802.11n.

So there's no use spending more to get an 802.11n card if your friend's equipment only goes to 802.11g.
Likewise there's no use getting an 802.11g card if your friend is limited to 802.11b.

Try an Ebay search on '802.11g card'. Or '802.11b card' or '802.11n card'.

There are a great many Chinese sellers selling small computer items new. It's up to you to decide whether to go that route.

Try to find a seller who gives complete specs on the card. And has over 99% positive feedback.

As for the directional antenna... Many can be found on Ebay using a search on 'directional wifi'. Some only cost a dollar. But they're only 6dB. You really need one rated 14 or 20dB. Those cost more.

A few webpage ads promise over a mile transmission distance with their directional antenna. So if you're lucky one of those might give you 300 meters distance.
hai bradtherad, really thanks
you gived the answer for me, great reply thanks again. I want to search for that items in ebay i will back soon thanks

I forgot to mention. Wifi cards are available inside small USB dongles. That's if you have a spare USB port to devote to it. This would be easy to use. But it needs to have an input for an external antenna.

And an 802.11g card will be compatible with 802.11b as well. The Windows OS (XP does anyway) permits you to select whether to use B or G.

If you use Win 98 then you may need a driver. Make sure the seller includes a cd with the driver.

No harm if you find a 802.11n card at a price you like. It will be compatible with B or G.

---------- Post added at 15:01 ---------- Previous post was at 13:10 ----------

And since we're at an electronics forum...

Here's a wikipedia article about a homemade directional wifi antenna:

Cantenna - Wikipedia, the free encyclopedia

Showing how to construct:

How to extend your Wireless Network by building a 2.4 gHz wifi cantenna

Antenna on the Cheap (er, Chip) - O'Reilly Emerging Telephony

**broken link removed**


You'll want to obtain a free program called Netstumbler.

It monitors your wireless card as to whether it's picking up a broadcast on any of the networking channels (1 to 11). Also shows how strong each signal is. I use it often.

It temporarily disables the Wireless Zero Configuration service. So if you have Win XP or later you'll need to get acquainted with that service.
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