Number of Clients and distance limit using AP Dongle

Summary

Would like to find out actual performance of AP Dongles vs Full size Routers. Can easily run 40/60 clients with full blown routers, need to know limitations if using this type AP Dongles either 150 or 300 Mbps.

We are operating in open classroom space, but would appreciate effect in both number of clients and distances reached if known.

http://www.edimax.com/edimax/merchandise/merchandise_detail/data/edimax/global/wireless_adapters_n150/ew-7811un/

System information

Windows 10, Full size Server Intel Core i7
Kalite 1.6.8
IE 11

Thanks

Frank

Hi @frankarl

You are linking to a device that’s intended to be used as a client, not an access point.

If you are going to serve up to 60 connected devices, I would suggest that you find an access point to handle that part.

I don’t think you’ll find data about the range and bandwidth of the above mentioned device if operating as an access point – chances are that it only does one adhoc networking and not AP mode, anyways. You can test that using this guide: https://askubuntu.com/questions/180733/how-to-setup-an-access-point-mode-wi-fi-hotspot/180734#180734

edit: Oh wait, you’re on Windows… you’ll have to find a different way to test the device’s AP mode in that case.

Best,
Ben

We are using these devices as AP’s and they work great. We can test with up to 14 clients and videos run flawlessly. We have tested so far 7 USB dongles that can operate as AP’s, we just do not know how many clients over 14 will choke these AP’s.

Thanks

Another great AP dongle :slight_smile:

Hi Benjamin,

We are planning to setup between 60 and close to 100 classrooms featuring around 30 clients each. Being able to use those USB AP dongles may result in savings over 10,000 US $ … major impact in project !!

Thanks

That’s a big investment and a huge deployment… it should be enough reason to do some thorough hands-on testing before buying 100 devices :wink: But really, those devices don’t look like something you’d wanna run 30 clients on. I could be wrong, and I would recommend trying to look for experience with the new RPi3 because it has a broadcom WIFI chip that supports AP mode. Perhaps people have experience with it.

You can read more about it here: https://www.raspberrypi.org/forums/viewtopic.php?t=138730

If you find a dongle with the same chip, it probably supports AP mode. But you also need a linux distribution with the right drivers to make it count.

So basically, if you buy these dongles and expect to make them work over a wider variety of devices and linux distributions (or Windows!?) then it’s a lot of uncertainty.

I’m not sure if you acknowledge the difference between AP mode and AD-Hoc mode, but it’s significant. I don’t think you can reliably connect 30 devices in an Ad-hoc network, nor can I recommend that you hand over unconventional and sort of “hacked” environments to schools and local system maintainers.

Regarding access points, you can also buy cheap APs. For instance, I have hundreds of dlink APs from a former ISP. I mean, just look for them, and you’ll find them. They are much easier to configure!

It’s over the top to spend $10,000 on 100 APs anyways, if you would go for such a low-spec device instead… you would be very well off spending ~$20 on real APs from a certified refurbisher. Preferably, but not mandatory, with a router function.

Good luck,
Ben

Hi Benjamin,

RPi’s are out of the question because schools already have Windows servers ready for this project. Actually have thousands of new desktop, laptop computers and tablets, unused due to lack of software and internet service. When I was talking about 10.000 $ I was referring to the differential between five dollar USB dongles and full blown routers. I am attaching a picture of four videos broadcasting thorough a 300 Mps EDUP Dong, and it is an under 10$ in the US, less if imported. This unit comes with solid Realtek software as in the picture, no hacks. Actually unit is sold as having an AP function, like quite a few other units we are testing. While of dual use, I am not sure you can qualify this as an AD-Hoc mode.

We certainly plan to do a lot of testing, but I am certainly interested in a way to find AP’s, are yours for sale ??

Do not need router functions, and would love to hear a source of potential refurbished AP’s.

Thanks a lot.

Frank

RPi’s are out of the question because schools already have Windows servers ready for this project.

I never said that, I just meant that you could look for WIFI adapters with the same chipset.

Do not need router functions, and would love to hear a source of potential refurbished AP’s.

I would suggest you buy them in a country that’s close to yours :slight_smile:

For instance, d-link has refurbished shop: http://shop.us.dlink.com/shop/shop-oulet/certified-refurbished.html

If you pay for the shipping, I can also send you 150 dlink dir-635… they’re not the greatest in the world, and some of them may have issues from the factory. But they’d have to be shipped from Denmark, so not sure if this would really be relevant as you can get much newer refurbished equipment easily :slight_smile:

I am in usually in the US.

Thanks for the link. We are going to do extensive testing next week with crowds of 30 to 60 clients using different devices, and will report the results.

Link listing USB Wi-Fi Dongles that support AP mode

http://elinux.org/RPi_USB_Wi-Fi_Adapters

Nice find @frankarl! Did you decide on a particular device yet?

Frank, I can share our experience in West Africa with RPi2 using USB WiFi dongles. They seem to work well with up to about 20 clients connected for accessing normal “RACHEL” content and even streaming Ka-Lite videos, but if students log in (which activates performance monitoring/logging) and access the math exercises, the system becomes VERY slow and many time-outs/disconnects if more than about 10 students work concurrently (Sometimes it chokes with as few as 6 connections). How much of this is due to the AP USB dongle and how much to the under-powered RPi processor is hard to say. We “upgraded” to the RACHEL Plus Content Access Point which Intel claims can handle 50 connections, and we find it exhibits the same symptoms when we exceed about 20 logged in connections doing Ka-Lite exercises, but it can stream to over 30 clients not logged in. Hope this helps you in your project.
Leon