As soon as you put your mobile in non-airplane mode and data is enabled, UE connects to LTE network using the attach procedure and you get the signal bars in your handset. There are so many messages exchange between UE and network before attach procedure getting completed.
After that when you browse any website by writing URL of that website, DNS query is triggered by UE to get the IP address of URL such as www.google.com. DNS server IP is communicated to UE by the network in "Attach Accept" message. UE uses the same DNS to resolve the URL for an IP address.
Once UE gets IP address of website, it makes TCP connection with server and exchange the web page content.
Doing DNS, TCP connection establishment and web page content deliver is common irrespective of technologies such as LTE, 3G etc.
Hope this will give you brief about LTE attach and browsing data. If you have any specific query then post the query.