Change VPN to access a Wi-Fi network?

I'm trying to connect to a Wi-Fi network that does not include mobile devices.
1) What part of my device is being stopped? IP, VPN, etc… Ie: What specifies the difference between a mobile device such as an iPhone and a laptop to a router/network?
2)If I enable a VPN, will I get around this problem and should it let me connect?
3) If yes, thanks. If no, what do I need to do so my iPhone 5 will be allowed on the network? Please explain the process and meaning behind it too. I'm pretty good with technological terms and catch on quickly.
Any help is appreciated!

I do not believe the network is distinguishing between phones and laptops. What I think you are experiencing is an incompatibility between your iPhone and the Wi-Fi network.

For some reason, certain wireless devices seem to be incompatible with certain networks. Sometimes the device can see the network but will refuse to connect to it. Sometimes the device will not be able to see the network at all.

I have had this issue a number of times. The most weird case I have experienced is with my old laptop that does not have an integral wireless adapter. I use a CardBus plug-in adapter. If I plug it into one slot on the laptop, I can see lots of networks including both my 2.4 GHz and 5 GHz networks from my dual band router. If I plug it into the other slot less that 1 centimetre away from the first slot, I can only see three networks. I can still see my 5 GHz network, but the 2.4 GHz network is totally inaccessible.

I have seen one or two questions that suggest that the iPhone 5 can have problems with certain networks.

If it is your own home network, then you could try adding a Wireless Access Point to your set up. You will have to do some practical research to make sure that whatever access point you pick does not show the same problems.

You might speak with the IT staff administrating the network you are connecting to. There are some know interoperability issues between some Wi-Fi manufactures and iPhones, but only the IT staff controlling the network could tell you if you were effected.

1) No clue. Again that's more of a question for the owner of the network. There are ways of "fingerprinting" devices and blocking them, so it is possible that's being intentionally done.
2) Nope, VPN requires a connection to the network in order to work, so you would just be using your cell carrier's network to establish the VPN.
3) Talk to the owner of the network.