You can do with a 3G dongle if you have a seperate IP address. Most Internet providers give NAT IP addresses and this doesnt work in your case. I contacted my Internet provider and got 2 SIMs which are on a VPN(they can talk with each other using the IP address.)
In this method here are the steps you follow.
- Install Netcat on Pi and Laptop
- Get the 3G dongles configured on Pi and Laptop so they can ping each other
- In laptop set netcat to listen on a specific port.(and transfer the received stream to mplayer)
- In Pi use netcat to forward the video stream to laptop's IP and port
You can also use VLC in which case you don't have to use netcat. The laptop's VLC player just access the VLC server installed on Pi.
If you can't get an IP address you can still use ffmpeg/motion to stream from Raspberry to some streaming service such as Justin.tv
When choosing a 3G dongle please find one with a good uplink speed. Most 3G dongles such as e220 have limited uplink speed.(around 300 kbps). New 4G dongles have better uplink speed.
When using dongles you might need to provide separate power.