Читать книгу Mobile Communications Systems Development - Rajib Taid - Страница 95

This chapter has introduced the core aspects of the understanding, design, and development of logical interfaces, their protocol stack, and its layers of mobile communications systems and networks. Logical interfaces are used to communicate among network elements of a mobile communications network. Logical interfaces are also used for the interworking and interoperations of mobile communications systems and networks, which shall be described later in Chapter 6.

Different terminologies are used to describe a logical interface, its protocol stack, and layers. Protocol layers are classified into user plane and control or signaling plane distinctly based on the nature of the information that is transmitted over a particular logical interface. Within the control plane only, protocol layers are also grouped into the AS and NAS categories, especially in the UMTS, LTE, and 5G networks and systems.

We presented the protocol layer termination and sublayering of a particular protocol layer found in mobile communications systems and networks. We also presented the general working model of a protocol layer that is used to communicate with its peer layer and provide services to an upper layer. Apart from this, we presented the general protocol model and layers of the UMTS UTRAN, LTE E‐UTRAN, and 5G NG‐RAN and their respective CNs.

A 3GPP technical specification may cover the description of GSM, GPRS, UMTS, LTE, and 5G system protocol functions and procedures. A method to identify the functions and procedures description that applies to a particular communications system was presented. Finally, the reader is recommended to focus on a particular logical interface, protocol stack at a time, and its specifications as mentioned in the references section and then, proceed gradually toward other logical interfaces and their protocol stack.