UTRAN user and Control Plane

The universal protocol model of the UTRAN interface is as follows:

Generally speaking, a communication network is composed of a terminal, a connection, and a network node (nodes). Links associates nodes. How can a message sent by the source terminal (Mo) reach the destination terminal (MT? The message passes through links and nodes until it reaches Mt. The key is how the nodes route the message to the final Mt. Therefore, the sent message must contain two parts:

1. content to be delivered by the user (SMS/email/some encoded speech) --- processed by the user

2. How does the data arrive at the Peer (route) through the network? It is processed by the control plane.

The wireless network layer and the transmission network layer are divided from top to bottom. You can refer to the TCP network or OSI network layer (physical layer-> transport layer-> Application Layer ). Accordingly, the wireless network layer can be seen as the UTRAN system's application layer, and the transmission network layer is the transmission layer (including the underlying physical layer ).

As for the user and control plane, this is actually based on the data type. In a communication system, user and control planes are generally divided. Users are real business data, such as voice data or group business data. The control plane uses signaling to control the establishment, maintenance, and release of a call process.

Correspondingly, the user plane at the wireless network layer is voice encoding (CS service) or grouped data packets (PS Service), that is, real user data. The control plane at the wireless network layer is the control signaling protocol: ranap (IU port), rnsap (IUR port), and NBAP (Iub port) are used to control the call process signaling.

The transmission network layer is the underlying load. Generally speaking, it is equivalent to a road. Therefore, its user surface includes both user data and signaling data, that is, the wireless network layer (control plane and user plane) all the things that come down are its user plane, carried by it for sending/receiving. The control plane of the transmission network layer is a separate control plane, which is only located at the transmission network layer and has no relationship with the wireless network layer, it is used to establish transmission bearer for user data at the wireless network layer (creating, maintaining, and releasing AAL connections ).