How are LAN routers, WAN routers and eNodeBs connected to each other (TCP/IP)?
I'm neither an IP Guru, but think i have a solid understanding of it and I just started working in mobile telecommunications. So I will try to help you here.
The problem in your understanding might be the fact, that the eNodeB is not directly connected to the Internet.
You probably should follow @Bimpelrekkie advice and have a look at the OSI Model to understand how this all works together.
Directly jumping into a mixture of Ethernet and mobile communications is hard. Maybe you should have a look at the EUTRAN=LTE basics, e.g. see https://en.wikipedia.org/wiki/System_Architecture_Evolution.
You simplified the eNodeB pretty much to some antennas and software. That might be true if you simplify it really much. I'll simplify as well, maybe it helps you.
The (simplified) task of the eNodeB is to transmit Data over the Air interface while making sure that each user gets a fair share of the air interface.
What Data is transferred must be differentiated between Userplane Data (Data that is actually &quot;useful&quot;) and Control Plane data (data that is used to control the connection).
the eNodeB (simplified) transfers the Userplane data to the Packet Gateway and from the Packet Gateway to the UE. The Packet Gateway is between the eNodeB and the Internet.
Have a look at this figure (you will understand it easier, if you have understood the OSI model):
https://www.slideshare.net/sofianonline/ip-concept-in-lte/7
(You can also search for &quot;LTE Stack OSI model&quot; or similar to get some other diagrams).
If you understand Ethernet or &quot;LAN&quot; a bit better, you should maybe compare the eNodeB to a WiFi Access Point. The WiFi Access Point does not directly &quot;talk&quot; IP. It gets IP packets from somewhere and is just (simplified) an Antenna which will put the IP Packet on the Air...
hope that helps