How do telephone companies connect our cellphones to to the internet?
|Dataplane||Base stations (eNodeB)||* Manage connections with user equipments (UE)|
|Serving gateway (S-GW)||* Enables seamless communication when the user moves from one base station to another, by storing a large amount of user states.|
|Packet data network gateway (P-GW)||* Enforce QoS policies
* Monitors traffic for billing
|Controlplane||Home subscriber server (HSS)||* Contains subscription information for each user, such as the QoS profile, access restrictions, and the associated MME.|
|Mobility management entity (MME)||* Coordinates handover of UEs|
|Policy control and charging rules function (PCRF)||* Flow based charging
* QoS authorization
Usually, in South Korea, one P-GW covers more than 3 million UEs.