Connecting to multiple IEEE 802.11 networks with one WiFi card
Learn more about MultiNet by clicking on the following links:
FAQ
Q: What is MultiNet?
A: MultiNet is a virtualization architecture
for wireless LAN (WLAN) cards. It enables the user to connect his/her machine to
multiple wireless networks using just one WLAN card.
Q: Why not use one wireless card for each network?
A: Such a scheme will cost you more money and what is
worse is that your machine will consume more energy (battery power). Also, in most
legacy laptops, it is cumbersome to fit multiple cards.
Q: Why will I ever need to use MultiNet?
A: MultiNet enables several new applications. For example,
with MultiNet you can connect to a guest's machine or play games over an ad hoc network,
while surfing the web via an infrastructure network. Another example is, you can use MultiNet
to connect your ad hoc network, which may contain many nodes, to the Internet using only one
node. Even more, you can make your home infrastructure network elastic by extending
its access to nodes that are out of range of your home WiFi Acess Point.
Q: Can I use MultiNet?
A: Yes, MultiNet works over Windows XP SP1.
You can download the software and try it out. Comments are very welcome.
Design and Implementation
The MultiNet virtualization architecture exposes multiple virtual adapters for each underlying wireless network card. It then uses a network hopping scheme that switches the wireless card across the desired wireless networks. However, the virtual adapters appear always active to the user as shown in the left figure. All the adapters appear as active to the user, although the card is only in network 2 at the snapshot instant.
The implementation of MultiNet is shown in the right figure.
MultiNet is implemented as an NDIS intermediate driver in Windows XP. It interacts with the card device driver at the lower end, and network protocols at the upper end. The buffering protocol is implemented in the kernel, while the switching logic is implemented as a user-level service.
Papers and Posters
Software Download and Installation Instructions
Click here for detailed download and set up instructions.
Collaborators
Date modified: 19th July, 2003