The basics on wifi range

[alkit]

Hi,

I have been doing hours of googling on extending wifi range, and can not seem to find a solid theory on how this all works. Below is what I've found so far and feedback on each solution. Any comments on the below would be greatly appreciated:

Typical scenario: John Doe is a basic internet user with a 10Mb/s internet connection. He doesn't care about NAS, USB, VPN, DMZ etc etc. He don't know what the words "network file transfer" mean. All John Doe wants is to have internet all over the house to use on his iPad, iPhone, xbox and laptop.
Currently, 2 rooms at the far end of the house get weak/no signal.

1) Upgrade the router - There seems to exist 2 schools of thought here. 1st school: a wireless N router is a wireless N router. Range will not get better with different units as they are all based on the same basic technology.
2nd school of thought: the higher-end routers give way more range than lower end routers... Even if the 2nd school of thought is right, does the high end router make enough of a difference to justify the much higher price? (Remember the scenario - nothing besides basic internet will be used over wireless)
2) Get a "high power" router - The general consensus is that this is a BAD idea. Reason being that the client wifi will not be able to "shout" back at the router. As John Doe will be using iPad, iPhone, Xbox and Laptop - we will not be upgrading the client wifi cards, so higher power in the router is pointless - correct?
3) Upgrading to a higher dbi antenna - Again, 2 schools of thought. 1: it will help extend the range to those two rooms that need it 2: Higher dbi will help somewhat, but such insignificant gains, that those two rooms will still be without wireless. In fact, there comes a point where the higher the dbi, the worse the vertical coverage will be. Additionally, noise will get picked up easier, and might even make the signal worse than before
4) A 2nd AP (via cable or powerline adapters etc) - This seems to be the most favoured way of extending a signal. However, in my personal experience I have found that this doesn't work as well as expected. When John Doe goes from his lounge into the far room, his laptop and iphone will try to stay on the WEAK wifi signal. They will not automatically move the the 2nd AP without manual user intervention. This makes it a bit impracticable for "mobile" devices?
5) A range extender - although not generally recommended because of reduction in speed, it shouldn't make much of a difference as we only need 10Mb/s. However, we are faced with the same issue as above re multiple access points.

So all in all - how does one actually extend the range in a way that everything will work seemingly together?

Thanks in advance for the advice!

 

[LoboX]

Hey m8 regarding the number 4 scenario, do you have the same SSID and password on all your wifi devices? Cause if you want to do roaming I have done it like that, just name all your wifi devices with the same SSID and pass, so when your client device moves from one place to another it doesn't need to log in on the other AP or router.

Hope this helps and good luck.

 

[LoboX]

Forgot to mention be sure to have your security settings the same

 

[sfx2000]

Another option - move the AP closer to the middle of the house if you can.

Alternately - if it's handsets/tables, you can try a repeater to light up the other end of the house - downside to repeater is that other clients may select it instead of the primary AP.

I would suggest using a tool like inSSIDer and do a site survey - do scans where most people are - might be as simple as moving the AP a few feet and selecting a different channel.

sfx

 

[alkit]

Another option - move the AP closer to the middle of the house if you can.

Alternately - if it's handsets/tables, you can try a repeater to light up the other end of the house - downside to repeater is that other clients may select it instead of the primary AP.

I would suggest using a tool like inSSIDer and do a site survey - do scans where most people are - might be as simple as moving the AP a few feet and selecting a different channel.

sfx

Thanks, but let's assume the router is already centered... Where to go from there?

 

[sfx2000]

Do the site survey first - inSSIDer is a free download - do that before spending any money on HW

 

[LoboX]

Thanks, but let's assume the router is already centered... Where to go from there?

When you are trying to get wifi signal to all your house depends on a lot of small details like, where exactly to have the routers or AP mounted, another thing you can try is hardware there a lot of HW better than SOHO routers, example Ubiquiti AP you can use PoE and will be able to move the AP closer to where you want to get it.

I still say scenario 4 is for you with the roaming

 

[LoboX]

Do the site survey first - inSSIDer is a free download - do that before spending any money on HW

^^^ do first what he is saying a site survey so you can see all the wifi signals, cochannels and overlapping channels, and see where you are loosing RSSI.

 

[stevech]

interference and competition with neighbors' WiFi does not reduce your signal strength (RSSI). It reduces your net speeds.

Survey that shows you how many SSIDs on what channels doesn't tell you what's important: which SSID(s) are heavily used.

 

[LoboX]

interference and competition with neighbors' WiFi does not reduce your signal strength (RSSI). It reduces your net speeds.

Survey that shows you how many SSIDs on what channels doesn't tell you what's important: which SSID(s) are heavily used.

OK so you are saying if i use InSSIDer and i see that there are 8 SSIDs and the RSSI on those SSID are -43dbm or -35dbm and my AP is -50dbm that is going to sacrifice my network speed?

The important thing is to know witch SSID people are using more? correct? I guess for you to see that you need a Spectrum Analyzer?

 

[Fraoch]

1) Upgrade the router - There seems to exist 2 schools of thought here. 1st school: a wireless N router is a wireless N router. Range will not get better with different units as they are all based on the same basic technology.
2nd school of thought: the higher-end routers give way more range than lower end routers... Even if the 2nd school of thought is right, does the high end router make enough of a difference to justify the much higher price? (Remember the scenario - nothing besides basic internet will be used over wireless)

The second school of thought is absolutely correct - have you seen the wireless router charts here on the site? There's a HUGE difference!

http://www.smallnetbuilder.com/lanwan/router-charts/bar/111-2_4-ghz-dn-c

In fact note over long distances some routers couldn't connect at all while others worked quite well:

http://www.smallnetbuilder.com/lanwan/router-charts/bar/111-2_4-ghz-dn-c?see=P_F

Sure, if it's nothing but basic Internet, high bandwidth won't matter, but if you can't connect at all the router is useless.

There are significant technology differences in n routers - dual-band, MIMO and proprietary client identification-tweaking algorithms like ASUS' Ai Radar.

2) Get a "high power" router - The general consensus is that this is a BAD idea. Reason being that the client wifi will not be able to "shout" back at the router. As John Doe will be using iPad, iPhone, Xbox and Laptop - we will not be upgrading the client wifi cards, so higher power in the router is pointless - correct?

Yes, it's not the ideal approach. As long as there's enough bandwidth for John Doe to request the page or download by HTTP then it might work, but as soon as there's any upload involved he'll notice it. Let's hope John Doe never discovers Dropbox, for example.

And of course higher transmit power also amplifies electrical noise so you can only go so far before you won't gain any more speed.

3) Upgrading to a higher dbi antenna - Again, 2 schools of thought. 1: it will help extend the range to those two rooms that need it 2: Higher dbi will help somewhat, but such insignificant gains, that those two rooms will still be without wireless. In fact, there comes a point where the higher the dbi, the worse the vertical coverage will be. Additionally, noise will get picked up easier, and might even make the signal worse than before

Don't know enough about external antennas to comment on them...

4) A 2nd AP (via cable or powerline adapters etc) - This seems to be the most favoured way of extending a signal. However, in my personal experience I have found that this doesn't work as well as expected. When John Doe goes from his lounge into the far room, his laptop and iphone will try to stay on the WEAK wifi signal. They will not automatically move the the 2nd AP without manual user intervention. This makes it a bit impracticable for "mobile" devices?

Indeed this is the best approach but you've touched on its weakest point - poor client networking software that does not allow seamless roaming. Sadly it doesn't look like any OS vendors are paying any attention to it.

5) A range extender - although not generally recommended because of reduction in speed, it shouldn't make much of a difference as we only need 10Mb/s. However, we are faced with the same issue as above re multiple access points.

In addition to the reduction in speed, there's also the addition of latency which might be high enough to actually be noticeable for simple web browsing. Also don't be so sure that your router can consistently and reliably deliver 20 Mb/s wirelessly in order to provide 10 Mb/s from an extender. Plus you have the multiple SSID problem as you've noted.

So all in all - how does one actually extend the range in a way that everything will work seemingly together?

There's no magic bullet, each approach has its drawbacks. Multiple APs over Ethernet, MoCA or powerline networking are the best approach but are hampered by poor SSID roaming.

Personally I went with the router with the greatest range.

 

[alkit]

The second school of thought is absolutely correct - have you seen the wireless router charts here on the site? There's a HUGE difference!

http://www.smallnetbuilder.com/lanwan/router-charts/bar/111-2_4-ghz-dn-c

In fact note over long distances some routers couldn't connect at all while others worked quite well:

http://www.smallnetbuilder.com/lanwan/router-charts/bar/111-2_4-ghz-dn-c?see=P_F

Sure, if it's nothing but basic Internet, high bandwidth won't matter, but if you can't connect at all the router is useless.

There are significant technology differences in n routers - dual-band, MIMO and proprietary client identification-tweaking algorithms like ASUS' Ai Radar.



Yes, it's not the ideal approach. As long as there's enough bandwidth for John Doe to request the page or download by HTTP then it might work, but as soon as there's any upload involved he'll notice it. Let's hope John Doe never discovers Dropbox, for example.

And of course higher transmit power also amplifies electrical noise so you can only go so far before you won't gain any more speed.



Don't know enough about external antennas to comment on them...



Indeed this is the best approach but you've touched on its weakest point - poor client networking software that does not allow seamless roaming. Sadly it doesn't look like any OS vendors are paying any attention to it.



In addition to the reduction in speed, there's also the addition of latency which might be high enough to actually be noticeable for simple web browsing. Also don't be so sure that your router can consistently and reliably deliver 20 Mb/s wirelessly in order to provide 10 Mb/s from an extender. Plus you have the multiple SSID problem as you've noted.



There's no magic bullet, each approach has its drawbacks. Multiple APs over Ethernet, MoCA or powerline networking are the best approach but are hampered by poor SSID roaming.

Personally I went with the router with the greatest range.

Thank you! This is exactly the kind of reply I was hoping for - someone to go through each point and clarify where needed.
Thanks for your time in giving a nicely detailed answer

 

[stevech]

- poor client networking software that does not allow seamless roaming. Sadly it doesn't look like any OS vendors are paying any attention to it.

Automatic best-AP selection while operating... isn't in the IEEE standard. That's why no vendors implement it.
Proprietary methods of doing that are provided, mostly by Cisco and Aruba for enterprise scale customers. The only real impetus for it is handheld VoIP devices such as those from Vocera - used in some hospitals for voice/work flow.

 

[Fraoch]

Here's a nice article on antennas vs. increasing transmit power:

http://www.smallnetbuilder.com/wire...516-why-high-power-routers-dont-improve-range

Good points:

Unfortunately, simply swapping out your current router for a high(er) power usually doesn't help increase your wireless coverage. The 802.11 standards that all Wi-Fi networks are built on use a "positive acknowledgement" protocol. That means each data packet (or frame) that is sent must be acknowledged by the receiver via a reply back to the sender. If no acknowledgement is received, the sender will try again and again until a timeout is reached and the sender gives up and drops the connection.

So when you increase the power on a wireless router or access point (AP), all this does is make it "shout louder". Sure, a wireless notebook in a dead zone may now be able to "hear" the router, where it couldn't before. But unless the client can shout just as loudly back, the client won't be able to communicate with the AP and the connection will be dropped or won't be made at all..

So increasing power will make a slow connection quicker but it won't solve a no connection situation because although the client might now be able to receive packets from the AP, the AP still won't receive packets back from the client and the connection will fail. You need to do something on the client side too, which the article addresses, or upgrade the APs antennas:

Increasing antenna gain gives you more flexibility because you can do it on the router / AP, or client or both. A higher gain antenna can succeed where higher power doesn't because it amplifies both the transmitted and received signals.

So you can install higher-gain antennas on your router / AP, leave the clients as-is and see real results.

...

But you need to move up to an antenna with at least 6dBi gain to see a performance difference. And you'll need to upgrade all the antennas on your AP / router to see any effect.