Wi Fi - antenna upgrade ?

[wong]

My wifi router (TP-Link ) seems a bit slow - speedtest.net shows a download speed of 0.9Mb/s download and 0.36Mb/s upload. The modem is connected to an extension, and I'm going to try it on the main socket to see if it makes much difference later this week (there was a thread on it recently) .

It also fails to reach the bedroom (several walls). Now the antenna that come with the router are 3dBi and omnidirectional. Would swapping the antenna for 7dBi (or more ) make much difference? or would directional antenna be better?

Also , some routers come with one, two or three (like mine) antennae. I asked at the shop and the salesman said I'd have to buy three replacements - one is for download, one for upload and hes not sure if the third? Sounds like he's not that knowledgeable.

[dudleybloke]

you could get a YAGI!

[Paul Drawmer]

Or a multi slot.

[Blown2CV]

Check the channel setting of your access point is set to same as your wireless adapter. Also check that both are connecting using G (54Mbps). Try the router plugged into the master socket. Also try an ethernet cable plugged into the router. Also try turning off microwaves and cordless DECT phones if you have them as they can interfere with 802.11g. . Use NetStumbler to see if there are any other wireless networks using your channel with a strong signal in the area and try changing the channel to see if that is any better. Do a line fault test with BT dialing 150 or whatever it is. Also call up your ISP and get them to do a roundtrip test to see what speed you should be getting. Try and find out how far you are from your exchange (not that you can do anything about that apart from move, but at least you can see if it that). Then, check on broadbandspeedtest.

[The Excession]

wong said:

My wifi router (TP-Link ) seems a bit slow - speedtest.net shows a download speed of 0.9Mb/s download and 0.36Mb/s upload. The modem is connected to an extension, and I'm going to try it on the main socket to see if it makes much difference later this week (there was a thread on it recently) .

First thing to do is to connect your comuter directly to the router with a CAT5 cable, this will illiminate the Wireless segment and give you a true readiing of what your ADSL line is supplying. Coonect via a cable, disable your wireless connection on your laptop/pc and run your speed tests again.

wong said:

It also fails to reach the bedroom (several walls). Now the antenna that come with the router are 3dBi and omnidirectional. Would swapping the antenna for 7dBi (or more ) make much difference? or would directional antenna be better?

Every 3dB on an antenna will double your signal strength, BUT, BUT, BUT there is no mystical/magic gain here. Antenna work by focussing the radio energy, typically for an omni antenna this is done by squashing the signal of a low dB antenna which is shaped like a sphere into the shape of of two saucers or plates. There is no magical gain in from antennas, so if your are sat above an low gain omni antenna and change it for a high gain antenna you can actually lose signal strrength. A directional flat panel antenna might get you through the odd wall or two but it will suck at working vertically.

wong said:

Also , some routers come with one, two or three (like mine) antennae. I asked at the shop and the salesman said I'd have to buy three replacements - one is for download, one for upload and hes not sure if the third? Sounds like he's not that knowledgeable.

You're right he hasn't got a clue.

When routers have more than one antenna it is called 'diversity switching' and this is based upon 'multipath reflections' basically the WiFi router listens on all antennas and transmits out on the antenna it got the strongest receive strength.

If you decided to buy a higher gain directional antenna (yagi or flat panel) and connect it to your router on one antenna port and then point this new high gain antenna in the direction you need it to work then it will behave perfectly.

You don't need three antennas unless you are trtying to get it all working in three different directions. The router will pick the best antenna to transmit on based upon the antenna that it got the strongest signal reception receiving from your pc/laptop.

So

[wong]

Thanks for the excellent replies.

Ive tried the main socket and its much the same.
The desktop is connected with a cable and that shows ~ 10 - 20 % improvement. I think I'll ask some neighbours what their speedtest results are like ( I live in a block of flats in Hong Kong).

As the wi fi has 3 antenna sockets, I may try one bigger rod type antenna and one directional one and see if that improves coverage.

Edited by wong on Tuesday 23 March 04:06