I recommend that if your needing a router with external antenna abilities, you should look into DIR-655 or 835, 825 models.
Thanks for your kind answer, but the DIR-655 or 835, 825 models are no mobile routers.
The DIR-506L has two functions I'm looking for:
- 3G/4G Connections via an USB stick
- WiFi Hotspot, building a local WiFi connected to an extern WiFi
An external antenna could be an advantage if I use the mobile router inside my RV camping car.