Management aspects are described in Chapter 9.
2.4.5 Network Maintenance
Apart from network elements and their software systems, a mobile communications network consists of various active and passive infrastructures and devices. Network faults cannot be ruled out during the peak load time. Periodic and preventive maintenance minimizes the chances of failures and network downtime. Various tools are used for fault detection as well as correction of network faults. Network management aspects are described in Chapters 10–12.
Each system engineering area that is shown in Figure 2.14 is further divided into different subject areas, such as requirements, design, and signaling. The implementation details of each of the management areas shown in Figure 2.14 shall differ as defined by the concerned 3GPP TSs, from the GSM to the 5G system. For example, in the case of the GSM system, ciphering and encryption are done for messages exchanged between the MS and the RAN only, whereas in the case of the LTE or 5G system, ciphering is also done for messages exchanged between the MS and the core network element. Also, the implementation details of a particular management area mentioned in Figure 2.14 may differ in the case of CS and PS call. For example, in the GSM system, ciphering is performed by the BTS, whereas in the GPRS system, the same is performed by the SGSN.
In this book, only the Mobility Management, Air Interface Management, Security Management, and the Network Management system engineering areas are covered. The interested reader is recommended to look for other resources for the subscribers and services management area of a particular mobile communications network.
2.5 Standardizations of Mobile Communications Networks
2.5.1 3rd Generation Partnership Project (3GPP)
In the preceding sections, we have discussed mobile communications network architectures along with their various network elements which are based on the GSM, UMTS, LTE, and 5G technologies. The interconnected network elements, either from the same or different OEM(s), provide end‐to‐end mobile communications and broadband services to subscribers. A network element communicates with another network element(s) through a standard protocol like the different PCs, and servers use Transmission Control Protocol/Internet Protocol (TCP/IP) and other protocols to communicate with each other over the Internet. There are international bodies that define and standardize various standard protocols such as TCP/IP, File Transfer Protocol (FTP), and Internet Control Message Protocol (ICMP). Similarly, the protocols and architectures used in a mobile communications network with interconnected network elements are defined and standardized by an organization called 3rd Generation Partnership Project, shortly called as 3GPP. It is a collaborative effort among different organizational partners. Those partners are ARIB, ATIS, CCSA, ETSI, TTA, TTC, and TSDSI, which are regional and national standards bodies, from Asia, Europe, and North America. See Figure 2.15.
The 3GPP and its organizational partners develop and standardize the architectures and protocols used in a mobile communications network. In a nutshell, start visiting the 3GPP site [1] right away to learn more about the 3GPP and its structures and crawl through the various information available under the different pages. The 3GPP site contains all the required information which is a key to know about the standardization processes of mobile communications systems and networks and their network elements that span across its different system engineering areas. A mobile communications network, consisting of the system engineering areas shown in Figure 2.14, that is conforming to 3GPP specifications is said to be a 3GPP compliant communications system.
Figure 2.15 3GPP organizational partners/members.
2.5.2 3GPP Working Groups
Within the 3GPP, there are four technical specification‐working groups (TSG) dealing with a particular area of work. Those groups are:
RAN,
Service and Systems Aspects (SA),
Core Network and Terminals (CT), and
GSM EDGE Radio Access Network (GERAN).
Each of the above areas/groups has further subgroups, such as RAN1, RAN2, RAN3, RAN4, RAN5, and SA1 to SA6, depending on a work area. For details, visit the specification group link on the 3GPP site [4] to know about the different working groups and their area of responsibilities. There is a table named “Project Co‐ordination Group (PCG)” containing hyperlinks for various working groups which could be explored further by clicking on the same. 3GPP specifies:
Maintenance and evolution of radio access technologies starting from GSM (2G) to 5G and beyond.
Maintenance and evolution of core network and system architecture starting from GSM (2G) to 5G and beyond.
Service layers such as GSM Services and IMS.
2.5.3 3GPP Technical Specification and Technical Report
In our day‐to‐day life, we use different electronic gadgets just in a plug and play way. Similarly, one can remove a SIM card from a phone, insert it into another phone with a different make and model, and start using it. All these are possible only when those devices are designed and works based on certain standards/protocols. The network elements of a mobile communications network are also designed and work on certain protocols as defined by the 3GPP. A particular protocol layer, and its various aspects, as defined by the 3GPP, is identified under a standard terminology called “Technical specification”, or “TS” in short. There is another terminology called “Technical Report”, shortly called as “TR”. A TR is for an informational purpose which is the result of a study phase/item on a particular area. A TR, later on, may lead to a technical specification. A technical specification is a standard specification as a result of a work item based on a TR.
A sample cover page of a 3GPP technical specification is shown in Figure 2.16. Look at the information that is available on the cover page of a 3GPP technical specification; see Figure 2.16. For example, 3GPP TS 22.060: “General Packet Radio Service (GPRS); Service Description; Stage 1” and 3GPP TS 23.060: “General Packet Radio Service (GPRS); Service Description; Stage 2”; and so on.
To decode and derive the relevant information, one must be aware of the nomenclature being used to identify a TS. Meaning and decoding of the various information available in 3GPP technical specifications are described in the subsequent sections of this book. Visit the 3GPP site [2] to get familiarity with the nomenclature. Knowing the nomenclature
