wifi signal is a 2 way line of communication?

[trauts14]

am i correct in that a wifi signal can only be as strong as the sender (AP for example) and the transmit power of your computer or adapter? for example if i have a 1000mw wifi booster, it is not worth it since the other communicating end (my laptop) cannot transmit that far? doesn't wifi transmit distance rely on both devices that are "talking to each other?

 

[Fraoch]

Yes, it is two-way communication but it depends what you're doing. Uploading anything from a client - absolutely, the better the client's antenna/signal strength is, the better the performance. No amount of signal boost at the AP will help a client's upload.

However for downloading, as long as the client has enough bandwidth to be able to request the download (i.e. it can access a webpage or FTP site) then it's not quite as important. Since most wireless communication is download, increasing signal strength does help, but it can only do so much.

Do note that increasing the transmit power is often counterproductive as it increases noise as well. You will probably find a "sweet spot" just a little bit above the manufacturer's default. Going way beyond may not help.

 

[trauts14]

thank you, that helps. i am getting an AP, but i was always curious about wifi boosters. thanks for the info on "noise" as well. I did not know that was a potential factor.

 

[Fraoch]

The best approach is to wire 2 or more APs to your router or switch. It involves running wire, obviously, but it's the best way.

Even placing the AP in the most central position will help as well.

 

[stevech]

When you just can't run cat5 to where an AP is going, you can substitute use of either power wiring IP (HomePlug, etc) or MoCA (existing TV Coax cables)

 

[sfx2000]

am i correct in that a wifi signal can only be as strong as the sender (AP for example) and the transmit power of your computer or adapter? for example if i have a 1000mw wifi booster, it is not worth it since the other communicating end (my laptop) cannot transmit that far? doesn't wifi transmit distance rely on both devices that are "talking to each other?

Getting back to the original question by the OP:

1000mw is 30 dBm at the power amplifier - add 3dB of gain, and you're at 33dBm - or effective radiated power of 2 watts - this is not good - read below...

Most Stations (clients) are power limited to about 16-18 dBm - or 40 to 63 mw at the PA, and depending on antenna design in a typical laptop, tablet or handset of 0 to 2 dB of gain - so best case is about 16 to 20 dB

Now this is all transmit power - most AP's, believe it or not, max out about 23 dBm on 20Mhz channels - wide channels is a bit lower.

23 dBm is about 200 mW, which to be a good neighbour is about as much as you want.

Now why I am bringing this up - well, the WiFi link budget is designed around this - stations (clients) and access points (AP's). More power is is not helpful - it creates noise, not just for your stations, but for your neighbours - as there a limited amount of channels/spectrum for use, and it's a shared resource. More power to you is more noise for the guy next door - and his wifi will suffer for it, because he likely has someone on the other side as well...

so in 2.4Ghz:

lower power on the AP, better antenna's on the stations - good
high power on the AP - not good
and of course, goes without saying - wide channels in 2.4Ghz, definitely not good

ultimately, at the end of the day, WiFi in 2.4Ghz is not limited by the AP, but by the clients - and at 16-20dBm - High Power AP's are a waste of money in many applications in the SoHo environment.

sfx

 

[trauts14]

thank you sfx. i was just curious as i have read boosters are not that great. i plan on using a POE AP since i have a POE switch and it can be hardwired. thanks for the full explaination as well.

also i assume when i install the AP i need to choose a good channel separation from the channel my router is using, and keep the SSID the same as my router so i can roam through the house and or yard without having to switch wifi networks? should the AP password be the same as the wifi router so when i am out of range from my wifi router the laptop will automatically switch from my router to the AP?

thank you for the assistance.

 

[sfx2000]

thank you sfx. i was just curious as i have read boosters are not that great. i plan on using a POE AP since i have a POE switch and it can be hardwired. thanks for the full explaination as well.

also i assume when i install the AP i need to choose a good channel separation from the channel my router is using, and keep the SSID the same as my router so i can roam through the house and or yard without having to switch wifi networks? should the AP password be the same as the wifi router so when i am out of range from my wifi router the laptop will automatically switch from my router to the AP?

thank you for the assistance.

Lot of it depends on location - school of thought is +/- 5 - if the primary channel is 6, go to 1 or 11 in 2.4Ghz - if that is not workable - then land on the same channel as the primary router, as they work together with the other STA's on the same SSID - but there can be a performance impact.

see what works...

 

[trauts14]

thanks SFX. i just posted a thread inquiring about 802.11N channels, but answered my question. i appreciate the help.