Set up Virtual WiFi for Windows 7

[TechGate]

Introduction :
Wireless Local Area Networks (WLAN) are also increasingly popular. Almost everyone I know has to be a home wireless router and use the freedom to surf with your laptop on the balcony on the Internet. A WLAN can be operated in two modes: Mobile devices such as laptops can be connected either directly themselves or with a common access nodes. In the first case we speak of an ad hoc network. This variation can be seen but very rarely, because it only shared data can be exchanged and no Internet access can be made. The second variant with a single access node is called the infrastructure network. It is used most frequently in connection with a wireless router that connects to the Internet (such as DSL) is connected to all clients is available to be shared.

[TechGate]

So far, it is that a wireless network interface in Windows can be operated in a mode. Either ad hoc or infrastructure network. Furthermore, one can be associated with only one wireless network pro wireless card at the same time. Until Windows Vista saw the Wi-Fi architecture like this:

Since 2002 worked Microsoft Research under the code name MultiNet on a virtualization of the Wi-Fi architecture. The results were as project VirtualWiFi presented to the public and used in several projects:

- Architecture and Techniques for Diagnosing Faults in IEEE 802.11 Infrastructure Networks
- SSCH: Slotted Seeded Channel Hopping for Capacity Improvement in IEEE 802.11 Ad-Hoc Wireless Networks
- WiFiProfiler: Cooperative Diagnosis in Wireless LANs
- Mesh Networking
- NetHealth

Designed for Windows XP, it has been downloaded over 100,000 times and in more than 400 universities as part of the mesh Academic Resource Toolkit distributed worldwide.

VirtualWiFi -
Abstracted a wireless card, so it several times as a virtual network adapter in the system appears. Each virtual card can then be separately configured by the user and allows connecting to different wireless networks at the same time on only one physical network adapter.


What you can now use it?
For example, you can wirelessly connect multiple computers simultaneously, about to play and simultaneously, the computer with a (paid) to connect a hotspot, then the client access to all share. Another example is the home network when the radio signal of WiFi access points in all corners of the house is not enough. With VirtualWiFi a computer can now work as a repeater and also increase the coverage.

In Windows 7 Microsoft seized on this technology and made it directly into the operating system. In the first step for the overall wireless architecture has been modified to integrate the Virtual WiFi infrastructure:

The next step, were added all the necessary functions to map a software Access Point (SoftAP) can. The largest part covers it from Microsoft. The manufacturers only have to support their network drivers SoftAP. For the extensive housing areas of the new technology was to support SoftAP as a condition for the performance of the Windows 7 Logo tests for the driver of wireless network cards made:

[TechGate]

In Windows 7, Virtual WiFi physical wireless card to a second virtual map add one. We call this new feature Wireless Network Hosted - hosted on German network. Find a manufacturer in the MSDN documentation for the implementation of Virtual WiFi in a 802.11 miniport driver:

- Virtual WiFi Initialization
- Virtualization Supported Configurations
- Virtual WiFi Implementation Guidelines

The basic setup, the network and the operation are controlled through the following functions:

- WlanHostedNetworkForceStart
- WlanHostedNetworkStartUsing
- WlanHostedNetworkForceStop
- WlanHostedNetworkStopUsing
- WlanHostedNetworkInitSettings
- WlanHostedNetworkSetSecondaryKey
- WlanHostedNetworkRefreshSecuritySettings
- WlanHostedNetworkQueryStatus
- WlanHostedNetworkQuerySecondaryKey
- WlanHostedNetworkQueryProperty


For users Netshell these functions are incorporated in the command. netsh wlan /? shows the basic usage:

- netsh wlan start hostednetwork
Starts the hosted network.

- netsh wlan stop hostednetwork
Stop the hosted network.

- netsh wlan set hostednetwork [mode =] allowed | disallowed
Enables or disables the hosted network.

- netsh wlan set hostednetwork [ssid =] <ssid> [key =] <passphrase> [keyUsage =] persistent | temporary
Configures the settings for the hosted network. There will always use WPA2-PSK with AES for encryption.

- netsh wlan refresh hostednetwork [data =] key
Updates the key for the hosted network.

- netsh wlan show hostednetwork [[setting =] security]
Displays information about the hosted network.

- netsh wlan show settings
Displays the global wireless network settings.


How did the acts now in practice? You need first a supported network card. The Windows 7 shipped with WLAN driver support for almost all the cards the hosted network. I have tested it with cards from Atheros and Broadcom itself. Only the driver from Intel dominated the necessary extensions so far. There will be an updated driver from Intel but we will put on Windows Update. Next, you open a command prompt as administrator and is following a line to:

netsh wlan set hostednetwork mode = allow ssid = "Virtual WiFi" key = "mh29-dyi9-txwt" keyUsage = persistent

The SSID and the key is to fit naturally in one's own desires. If you have entered everything correctly, you get in response:

- The mode of the hosted network is such that the hosted network is allowed.
- The SSID of the network was hosted successfully changed.
- The user key pass phrase of the hosted network was successfully changed.

In the Device Manager, then we get a new network card:

It appears as two wireless network system in:

With netsh wlan start hostednetwork then you start the hosted network. Windows 7 is the new host adapter automatically with the new network to connect to

And ask the user how he would classify the network. I have chosen in the example above, "Work Network". The default setting is "Public Network":

Information on the current status can be obtained with hostednetwork netsh wlan show:

Settings for the hosted network 
----------------------- 
    Mode: Allowed 
    SSID name: "Virtual WiFi" 
    Maximum number of clients: 100 
    Authentication: WPA2-Personal 
    Encryption: CCMP

Status of the hosted network 
--------------------- 
    Status: Started 
    BSSID: 00:21:00: ed: cb: 7b 
    Funktyp: 802.11g 
    Channel: 1 
    Number of clients: 0

We see that the network is operational and has not yet connected client. If one now on a different client, the network icon in the taskbar bottom right clicks, the new network will appear as a normal wireless network and can be connected accordingly:

If you now have, for example, are booked into a hotspot, you can create with the help of the network hosted a second Wi-Fi, the only one is even available. Here you can then incorporate other laptops, gaming consoles, music players with wireless Internet, smart phones, etc. and share the Internet through the hotspot. Saves me the future, the entrainment of a wireless router when I'm on the road again. So that members of the hosted network can use the Internet together, activated only in the properties of the wireless network that is connected to the hotspot, the sharing of your connection and wireless network connection 2 are set as a home network connection. One could also, of course, other types of Internet access wirelessly share. The wire can access via an Ethernet cable, as well as its wireless access via UMTS, if the UMTS card can be set as dial-up connection in the system. Windows 7 will then act as a gateway between the networks. The hosted network is being sealed off while using NAT to access from the external network. A DHCP server is started automatically by the configuration of Internet Connection Sharing and assigns to the clients IP addresses from a predefined segment. To stop the hosted network is there netsh wlan stop hostednetwork one. The hosted network exit.