extend your Wi-fi coverage with a second access point

There are also many questions on the net on how to  extend your Wi-Fi with a second Wi-Fi Access point  or how to connect a second router. Let’s imagine  that you have a house with two floors or stories  and you have that Wi-Fi access point on the  first floor. You now want to extend the reach  of your Wi-Fi network in the house, let’s say  to the second floor. 

How can this be achieved ? Many people these days use Wi-Fi Meshes to do  this. A Wi-Fi mesh basically is just a bunch of  Access points which extend the Wi-Fi network. That  means you can move from one room to the other,  and your tablet or phone would seamlessly  connect to the node in the mesh that delivers  the strongest signal without even noticing that  it has switched from one node to the other.  

But the nodes need to communicate with each other.  In a true wireless mesh that happens over radio.  So in fact they will occupy multiple channels.  At least one in order to communicate with your  tablet or phone on one side, then at least  one in order to communicate with each other,  and at least one in order to talk to the router.  They are awesome. 

They are however quite expensive  and also very often proprietary, that means that  you lock yourself in to a vendor and might not  be able to mix and match components from other  vendors. A cheap alternative to mesh would be to  just throw in a second Access point. So we would  have that Wi-Fi Access point on the first floor  and a second one let’s say in the bathroom of the  second floor. There are just a couple of things  you need to keep in mind when you configure them.  If you have watched my video on Wi-Fi basics –  here’s a card again – click the info icon to watch  it – then you know everything about Wi-Fi channels.  

Another thing we need to know about is  roaming. Let me show you what I mean. Let’s say I am connected to  the Wi-Fi on the first floor.  Everything goes well, beautiful  and fast internet connection on my  phone. Watch the little beacons or bars on the top  right of my phone – they tell me Wi-Fi is great. I  now start watching a video on the internet  and at the same time I am moving or let’s say  roaming towards the basement. What will happen ?  

The Wi-Fi signal from the 1st floor becomes weaker  as I move and the signal which I receive from the  basement becomes stronger. But my phone does not  pick up the signal from the basement, it will  just bluntly remain on the weak access point. So we can see that the roaming does not work the  way we want it to work - Unless I had configured  the two access points in the following way: 

The  2nd access point which I am throwing into the  network needs to be transparent on layer 3 –  that means that it should not act as a router,  but rather as a bridge on layer two –  bear with me, I’ll explain in a second.  In other words, everything that is IP address,  subnet,etc. needs to remain the same. Also,  the two access points need to have the same  ESSID – that means the same Wi-Fi network  name and the same password. Only the hidden  network identifier, the BSSID will be different  and also I need to put them on different  Wi-Fi radio channels. I am doing this  because I do not want them to interfere which  each other on a radio level. In this example,  I call both networks onemarcfifty with a password  the Wife on the 1st floor is on channel 36,  the one in the basement is on channel 64.  

The BSSID has been assigned automatically,  I do not have to worry about that.  What happens now when I move is that my  phone gets offered the same network name  but with a much better signal. The same  thing happens if I use a laptop or tablet.  Now – depending on the mobile device that I use,  the so called roaming aggressiveness is different.  

The roaming aggressiveness describes the willingness of a device to change from one  access point to the other. Apple for example have  made changes to this starting with the iPhone  5s where they increased this value. And actually  there is a whole article on this by apple support.  Under windows this is called roaming sensitivity  level and can be configured in the control panel.  

I will provide the links to the articles in  the video description. So does this really  work ? Is Marc saying that I can save the  500 bucks for a mesh and rather spend 50 or  70 bucks on a second Access point ? I am afraid  yes, that’s what I am saying. Just keep in mind  that this is a DIY channel and that it involves  tweaking stuff – if you don’t want to do this,  go for a mesh – as I said, they are great. 

But if  you’re not afraid of tweaking a couple of settings  then that might save you a bit of money  and also be a great learning experience.  For this solution you do however need an Ethernet  connector for each additional Access point  as the access points would not communicate  with each other over wireless radio  unless they are mesh-able which means of course  a higher price. Before I explain the setup and  the layer 2 and 3 implications please  let me actually prove that it does work.

Let’s continue where we left off –  I have just arrived in the basement,  Wi-Fi gets weaker, I move closer to the  2nd access point, it takes up to three  seconds and – bing – we are on the other Access  point. No interruption in the video or whatever.  Walking back upstairs – same game – as  soon as I get closer to the router in  the staircase – it takes up to 3 seconds again  and it picks up the signal. Good enough for me. 

I still owe you an explanation on how to configure  the Access point on layer 3. When I connect a Wi-Fi  router to a network line, then typically the  router gets assigned an IP address by the ISP.  If I connected the second Access point in my  case behind that router, the same would happen  but this time the first router would assign an  IP address to the second router. I would then  have a different IP range upstairs than I have  downstairs. Or – in networking terms – a different  network or subnet. 

That’s not a big drama as  such and it might actually be that you want it to  work that way, for example if you rented out the  upstairs apartment to a third party and you would  want to have a firewall in between to protect your  own network assets. You would just need to make  sure that the two IP address ranges are different,  so you can’t use 192.168.1.x on both devices.  

But in our case we don’t need that. Furthermore,  that IP address negotiation takes time and it  might break existing connections such as the video  I am streaming. Or I might not see that printer on  the first floor any more if I am connected to the  second floor. So I need to actually connect the  Wi-Fi and the Ethernet on the second floor on layer  2 – that’s called bridging. Both interfaces will  be on the LAN segment and there will be no routing  or firewall between the 1st and 2nd floor. 

How do  you configure this ? Well, in theory it could  just be enough if you plugged the network cable  into the LAN port of the second router rather  than into the WAN port, but there is no guarantee,  it depends on the vendor and the firmware etc.  If you are using an open firmware such as OpenWrt  you can configure this explicitly. Just Google  for “OpenWrt dumb access point” and it will point  you to that article on the OpenWrt Website.