Whats Local Area Connection of my USB 3G modem

Hi I have a question,my computer have no external Network Card .I have installed Huawei 3G USB modem and in windows I have a dial up connection,but in Network Connection I also have a "Local Area Connection 4" by Huawei Mobile Connect Network Card and it shows Network Cable Unplugged" my question is what is this "Local Area Connection 4" what's its use .

This same thing goes for my bluetooth dongle in that case it creates a Bluetooth PAN Network Adapter(I guess Private Access Network).

if its for sharing network,why its says its unplugged because its wireless for bluetooth and in case of Huawei it doesnt make sence at all as it doesnt even have Wi-Fi or any other mean to connect any other device...

I have also have a screenshot here see attachment...I am using Microsoft Windows XP

I dont understand to much of these Network stuffs ,but I am interested if you people have some resource from where I can read some it will be great,Google was not much help in this case...

Thanks

Ok after learning a bit about networking, I learnt that my question may be related to networking but my answer is not directly related to networking, so Google was not much helpful as I was searching in wrong area. I suddenly remembered one of my projects communicating with PC with a microcontroller using USB and their was my answer already...

In short I will answer my question

USB (Universal Serial Bus) is used to communicate to all most any peripheral found today, it use USB protocol to communicate with other devices, but their are already many different protocols for particular job ,they are standardized and they are use by majority for example networking the preferred protocols are Serial or Ethernet. If you remember their were dial up serial modems also called COM port modems connected to serial/COM port of the PC or if you recall high speed Ethernet modem connected to Ethernet port of your PC,these ports are missing in new PCs,we all have USB ports now.
So now we are using the same protocol Serial or Ethernet, but with a different physical interface USB. What happens when you use a USB modem you install USB modem drivers ,these drivers are software’s which exposes the USB modem as a virtual serial modem or a virtual COM port to the operating system in case of serial communication. The operating system communicates with the virtual serial/com modem as it would communicate with a real modem, and the USB driver converts these information passed by OS to the virtual serial/com modem into USB protocol to communicate with the real physical USB device modem. In case of Ethernet its same its just the USB driver exposes the USB modem as a network adapter/card to the operating system.

In my case the Huawei Mobile Connect Network Card showing up in my network connection is just virtual network interface, it physically doesn’t exist. But the Bluetooth PAN Network Adapter exist as you can make a network using Bluetooth. I have also virtual com port ,which is used by my Samsung Mobile's modem.

Lesson learnt never say Google doesn’t works…