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How to connect 100 WiPy (Station mode) to a 1 WiPy (AP mode)?

Posted: Fri Mar 04, 2016 2:46 pm
by beyonlo
Hi all.

How is possible to get more than 8 WiPy clients (station mode) connected at ONE WiPy (AP mode) if the TICC3200 specification say about just 8 simultanous connections?
From http://www.ti.com/product/CC3200:
--------------------------
TCP/IP Stack
Industry-Standard BSD Socket Application
Programming Interfaces (APIs)
8 Simultaneous TCP or UDP Sockets
2 Simultaneous TLS and SSL Sockets
--------------------------

I mean, I would like to connect 100 WiPy Station mode to 1 WiPy AP mode (I want the WiPy as AP). The 100 WiPy will send the data simultaneously.

Thank you.

Re: How to connect 100 WiPy (Station mode) to a 1 WiPy (AP mode)?

Posted: Fri Mar 04, 2016 3:09 pm
by danicampora
Hi beyonlo,

Actually, you can't connect more than 1 WiPy to another WiPy. In AP mode it only allows 1 STA to be connected, this is a limitation of the CC3200 itself.

Cheers,
Daniel

Re: How to connect 100 WiPy (Station mode) to a 1 WiPy (AP mode)?

Posted: Fri Mar 04, 2016 5:48 pm
by beyonlo
Hello Daniel.

That is terrible for my project. :(
Anyway I have three important questions about many-to-one connections:

1. Tell me, what is the advantage of a WiPy running in AP mode if you can to have just one client connected? Because, for one-to-one, the Wifi-direct is fine.
2. Thinking that limitation is just on AP using the WiPy, is possible to have 100 WiPy (station mode) connected with a normal Wifi AP (linksys, dlink, ubiquiti, etc)? Don't worry about AP boards capacity, just about WiPy. Theoretically, for me, that is fine.
3. Will be the LoPy (ESP32) come with this limitation, like as WiPy (CC3200)? If not, I will to buy some LoPy - still have a time on kickstarter! And, could you tell me what is the limitation number on LoPy running as AP Mode - for clients connected? Or the limitation is just the power to processing the clients? I checked the ESP32 datasheet and found nothing about AP mode limitation. My intention is to use LoRa as WAN (client), and the Wifi running as AP mode, and receiving 100 clients - WiPy (or any other wifi board) connected. That is important to me.

Ps: I need to run everything using SSL/TLS - just the the WiFi network, of couse

Re: How to connect 100 WiPy (Station mode) to a 1 WiPy (AP mode)?

Posted: Fri Mar 04, 2016 6:31 pm
by dhylands
One advantage of running the WiPy in AP mode means that you can connect to the device (using say your phone), enter an SSID and password and then have your WiPy connect in STA mode to your network.

If the WiPy fails to connect in STA mode (because its moved outside the range of the AP it was connecting to), then it could fall back to AP mode.

Re: How to connect 100 WiPy (Station mode) to a 1 WiPy (AP mode)?

Posted: Sat Mar 05, 2016 2:16 am
by beyonlo
Daniel, could you to answer the question 2 and 3?

Thank you.

Re: How to connect 100 WiPy (Station mode) to a 1 WiPy (AP mode)?

Posted: Sat Mar 05, 2016 6:07 am
by pythoncoder
I'm no expert on this but I'd have thought having 100 devices on any WiFi network was pushing it if a significant number of them were to try to communicate concurrently. A limitation is the number of channels, see https://en.wikipedia.org/wiki/List_of_WLAN_channels.

In station mode the WiPy is just a conventional WiFi device. I think question 2 is a generic question about the capabilities of 2.4GHz WiFi networking; as such perhaps it's worth seeking expert advice elsewhere?

Re: How to connect 100 WiPy (Station mode) to a 1 WiPy (AP mode)?

Posted: Sat Mar 05, 2016 6:32 am
by Roberthh
If you look into the product sheet of a typical low cost home router or access point, they tell that they can connect up to 128 devices. Let's assume that this is only a theoretical number, which says, that these are connected and silent most of the time. Both pythoncoder and dhylands pointer at possible bandwidth limitations. But practically thats is what I would do - use a single more powerful AP just as the connection hub, and leave all other WiPy's in station mode. Still one of them can be a 'logical' master, if that is intended for your project.

Re: How to connect 100 WiPy (Station mode) to a 1 WiPy (AP mode)?

Posted: Sat Mar 05, 2016 10:15 am
by danicampora
Hi benyolo,

Regarding question 2, yes, that is possible, and there's no limitation on the WiPy related to that. As the others have pointed out you will need a high end router and also be mindful about the bandwith limitations.

Regarding question 3 I need to ask Espressif about the AP limitations of the ESP32, but my initial guess is that it won't be able to handle 100 devices either, probably less than 10.

Any support on the LoPy campaign is much welcome, even if it's just 1 EUR ;-)

Thanks. Cheers,
Daniel