5G and Anchoring - What is Anchoring?

Hi Guys;

A quick question please. What does anchoring mean in 5G context. When i talk to a RAN guy (i am an ip network engineer), he tells me that a co-located LTE 1.8 GHz band (2x 10 MHz bandwidth) is used as the anchoring carrier of 5G NR. What does it mean?


At 5GNR NSA Option 3x (currently what is being used), you still need an anchor, a leg, PCELL, on LTE to allow 5G to be used, meaning, you are connected simultaneously on LTE and NR. This anchor, or leg, PCELL, is where all the control plane information goes, while on NR only user plane data.