Connect two wireless+wired networks wirelessly?

Is there any mode, when wireless device or access point can serve both as access point for clients and as a bridge between two wireless networks?

Like here:

enter image description here

UPDATE

Also I would like to have ONE wireless device (router, AP, etc) in each part of the networks and also want these parts to be independent, i.e. if one AP down, then only it's clients are down, having clients of other AP communicate with each other.

UPDATE 2

Probably the answer is related to so called WDS, which is not standartized.

I don't understand why do remarks below are so often repeated:

1) two radio nodes can't transmit simultaneously

This is not a point because this is true to any Ethernet too. Two wired cards also can't transmit simultaneously.

2) repeater reduces speed twice because it should have time to repeat all it hears

This is also not a point because single Access Point also repeats when connecting two wireless devices. Communicating between two wireless devices with one access point also reduces speed twice

3) it is dangerous to connect something to Internet

Question is unrelated with Internet. We are speaking about LAN.

I am coming to conclusion that it was made a serious design mistake while designing WiFi protocols, because implementing WDS looks straightforward and should be implemented in standard AP protocol.

Dims

Posted 2014-10-08T08:55:08.750

Reputation: 8 464

could you tell me what hardware you are using? i.e. the router type – DarkEvE – 2014-10-08T09:05:12.440

I will select hardware when know what features required – Dims – 2014-10-08T09:09:06.400

ok, also what is the purpose for this setup? – DarkEvE – 2014-10-08T09:11:26.750

To connect two parts of subnet or two subnets wirelessly – Dims – 2014-10-08T09:12:27.563

So, this is basically is a network with 2 segements, so each segment is the AP with its respected nodes connected to it? – DarkEvE – 2014-10-08T09:14:26.190

– akira – 2014-10-08T09:25:29.160

@NabilAziz yes, but there is no physical connection between APs – Dims – 2014-10-08T12:41:00.770

@Dims: "remarks repeated": coz not everyone is as clever as you and understand the fundamentals. shock. also, there is no "he knows the fundamentals"-tag on your avartar. shock2. if you want to answer your own question with your conclusion: go ahead and do so. – akira – 2014-10-10T14:46:20.627

I am not claim I am clever. Contrary, I presentin my thoughts because I would like to learn my mistakes. – Dims – 2014-10-10T16:58:35.667

Answers

Ok so there are many ways to do this, but I you should be aware NEVER connect your local network to an AP which is connected to the internet as this would allow people to access your network.

Also make sure you set your Wireless access points 6 channels apart to avoid interferance as they are too close.

So firstly AP's can not communicate with each other wirelessly with consumer grade products, they only communicate with wireless clients, so you would need what is called a "Wireless Bridge" to connect both AP's together.

Here is a brief description on the possible modes you can set with a wireless bridge, obviously you can decide which one fits your needs.

Point to Point

This will connect the two segments using two bridge products, one unit is set to master whilst the other is set to slave.

This is a brief picture

enter image description here

Here is a website link describing how it is setup http://www.tp-link.com/en/article/?faqid=176

DarkEvE

Posted 2014-10-08T08:55:08.750

Reputation: 377

I have a consumer wrt54gl with tomato firmware that can be a wireless bridge cost me $75 – Sun – 2014-10-08T12:38:08.907

This situation is called "Wireless repeater": AP2 talks to AP1 as it's client and shows up under the same BSSID as AP1. The downside is that you cripple the overall bandwidth.

To quote some helpful thoughts from http://forums.whirlpool.net.au/archive/1631183:

There's one important point to understand first before discussing devices. Wireless uses a shared medium, that is a specific radio frequency, only one device can be transmitting at any time otherwise the signals would interfere with each other and could not be understood by anything else. Also, for the same reason a device cannot be sending at the same time it is listening.

And

There's two types of devices that you can use to extend the range of a wireless network. First is a wireless repeater, basically it listens to the frequency being used, whenever it hears something it sends it out again, because it's in a different location to the first station the signal gets sent out further. However, due to the above fact about wireless networks, if you use a repeater the throughput is effectively halved because for each second it spends listening it needs a second to send it, thereby taking twice as long to send data.

Just a side note: Again, only one device can be transmitting at any time. By adding repeaters you are not improving the situation, throughput wise. You are just adding another party which shouts it's stuff through the air. If more parties shout, it's harder to understand anything. The same is true for the power of the Wifi-Signal (think of loudness): Just because you can now shout louder does not improve the general situation. It would be better to make AP2 talk to AP1 over a different medium (cable, powerline, 2nd channel or other AP) and to make the radius of the circle non-overlapping ("reduce the loudness"). I am aware of the fact that sometimes the reality (budget, hardware, locality etc) dictates what you can use.

akira

Posted 2014-10-08T08:55:08.750

Reputation: 52 754

Will repeater work if second network disappear? Will it still serve it's clients individually? – Dims – 2014-10-08T09:03:22.013

If AP2 goes down and the client's can't reach AP1: These clients will go down as well. If AP1 goes down, there is nothing to repeat from. And, since AP2 has no connection to the outside on it's own, all of AP2's clients will have Wifi but they will wonder where these damn IP-addresses are :) – akira – 2014-10-08T09:06:29.850

Won't they have addresses they were assigned previously or static? – Dims – 2014-10-08T09:11:09.447

So, you want to say, that standalone repeater will serve as Access Point? – Dims – 2014-10-08T09:11:40.113

P.S. On Ethernet also only one device can be transmitting at a time. There is no point here. – Dims – 2014-10-08T09:14:19.553

Addresses: when they come over DHCP from AP1 (or a DHCPD connected to AP1) then the clients of AP2 will lose connection to that DHCPD. if clients of AP2 have either static IPs or keep them (in whatever way) they might talk to each other (coz they are attached to the same "ethernet" (wirelessly :)) – akira – 2014-10-08T09:14:57.170

Forget about DHCP. There is no matter how I am assigning IP addresses. I can have two DHCP servers or assign addresses statically. – Dims – 2014-10-08T09:16:42.760

@Dims: yes, but with real cables you can put switches between the cable-parts. and you can put different cables next to each other which are not interfering which each other either. the point was just to ... highlight this "known" fact for these folks who think throwing more repeaters and extenders into the pool of wifi-devices will improve the situation, it was not intended as some kind of "attack". – akira – 2014-10-08T09:17:13.073

So, you state that standalone repeater is equivalent to access point? – Dims – 2014-10-08T09:17:25.660

Will standalone repeater check wireless passphrase for example? – Dims – 2014-10-08T09:18:48.790

@Dims: I state what I have answered: The mode you describe with your picture is regularly called "Wifi Repeater", AP2 acts as a repeater: It receives signals from it's clients and shouts them out to whoever wants to listen (AP1 will pick up these signals since it is in the range of AP2). – akira – 2014-10-08T09:19:19.467

@Dims: The repeater takes everything it gets and repeats it. Passphrase-requests etc as well. – akira – 2014-10-08T09:21:05.253

Who will check repeated passphrase-requests if AP1 is down? – Dims – 2014-10-08T09:22:14.160

@Dims: no one. Since a repeater is a very dumb piece of hardware: It takes, what it picked up and shouts it out. – akira – 2014-10-08T09:23:27.687

If nobody will check passphrases then no wireless client will be able to connect to repeater and AP2 network will no function. So this is not what I need – Dims – 2014-10-08T09:25:54.800

This might not be what you "need" but that's what you have pictured above. If you need a redundant central router to which either AP1 and AP2 are connecting to keep their clients "on" then this is a different picture. If AP1 goes down there won't be any connection between the machine in the top left and the laptop in the bottom right of the picture. You can of coz operate AP1 and AP2 in pure AP mode and use other means to connect the two of them, cable, power-line, wifi-hw which have multiple antennas to operate multiple channels etc. – akira – 2014-10-08T09:32:26.503