there are many ways to perform.

|| i recommend the emulation way, we tested ok (this year), using gns3 (http://www.gns3.net/) and real ios (cisco) or junos (juniper) router os. we create topologies and charge real configs on nodes.

-- please review it, a good alternative to virtualize routers ||

-- || other alternative is: quagga [http://www.nongnu.org/quagga/ ] running in a virtual machine over win7. | this was a previous alternative, there are many others, i tested it long time ago ||

-- about mobile, yes you can integrate, crossover between mobile nodes and e.g. gns3 --|||

-- a howto using gns3 and wireless links: http://www.slideshare.net/rusevi/gns3-05-tutorial

and additional info of wireless routers, e.g. tomato, on: http://en.wikipedia.org/wiki/Tomato_firmware or e.g. openwrt |||

Http://research.microsoft.com/en-us/um/redmond/projects/virtualwifi/

The basic idea is TDMA

If you are talking about Wireless Hosted Network (Virtual Wifi) where you can turn your PC into a WLAN AP: all you need is the protocol implementation of the access point. In 802.11 there are three modes of operation, client, infrastructure, and ad hoc. Normally the driver of your WiFi-card uses the client mode (search for APs, authenticate, associate, talk to the AP, ...). But with a different driver you can also execute the protocol of the AP (send beacons, reply to auth and assoc, etc.). Windows 7 just ships the AP driver as well so that you can run the infrastructure mode easily. The hardware supports all modes from the beginning, but the new thing is that you also have the AP mode because the OS supports it.

There is more information at

http://msdn.microsoft.com/en-us/library/windows/desktop/dd815243%28v=vs.85%29.aspx

it also describes the virtual WiFi card is that is what you are after.