Mobile Communications Systems Development. Rajib Taid

Robust Header CompressionRR Radio ResourceRRC Radio Resource ControlRS Reference SignalRSRP Reference Signal Received PowerRSRQ Reference Signal Received QualityRRM Radio Resource ManagementRTOS Real‐Time Operating SystemS1‐AP S1 Application ProtocolSA Standalone ModeSAP Service Access PointSAPI Service Access Point IdentifierSBA Service‐based ArchitectureSBI Service‐based InterfaceSCP Service Communication ProxySCTP Stream Control Transmission ProtocolSDAP Service Data Application ProtocolSDCCH Standalone Dedicated Control ChannelSDN Software Defined NetworkingSDU Service Data UnitSD Slice DifferentiatorSEAF Security Anchor FunctionalitySEPP Security Edge Protection ProxySFN System Frame NumberSFI‐RNTI Slot Format Indication RNTISGSN Serving GPRS Support NodeSIB System Information BlockSLA Service‐Level AgreementSMP Symmetric Multicore ProcessingS‐GW Serving GatewaySI Skip Indicator/System InformationSM Session ManagementSMS Short Messaging ServiceSMF Session Management FunctionSN RLC Layer PDU Sequence NumberSN Secondary NodeSNDCP Subnetwork Dependent Convergence ProtocolS‐NSSAI Single Network Slice Selection Assistance InformationSNPN Standalone Non‐Public NetworkSSC Session and Service ContinuitySST Slice/Service TypeSPS Semi‐persistent SchedulingSR Scheduling RequestSRVCC Single Radio Voice Call ContinuitySRB Signaling radio bearersSRS Sounding reference signalSSB Synchronization Signal BlockSSS Secondary Synchronization SignalSS Supplementary ServicesSS/PBCH Synchronization Signal Physical Broadcast ChannelSS‐RSRP SS Reference Signal Received PowerSS‐RSRQ SS Reference Signal Received QualitySS‐SINR SS Signal‐to‐Noise and Interference RatioSTL Standard Template LibrarySU‐MIMO Single‐User MIMOSUCI Subscription Concealed IdentifierSUPI Subscription Permanent IdentifierTAC Tracking Area CodeTAU Tracking Area UpdateTCH Traffic ChannelTCP/IP Transmission Control Protocol/Internet ProtocolTDD Time Division DuplexTI Transaction IdentifierTFT Traffic Flow TemplateTNL Transport Network LayerTPC Transmit Power ControlTRX Trans‐receiverTS TimeslotTTI Transmission Time IntervalUCI Uplink Control InformationUDM Unified Data ManagementUDP User Datagram ProtocolUDR Unified Data RepositoryUE User EquipmentUm GSM Air InterfaceUML Unified Modeling LanguageUMTS Universal Mobile Telecommunication SystemUu UMTS/LTE Air InterfaceUPF User Plane FunctionUTRAN UMTS terrestrial radio access network UMTSURLLC Ultra Reliable and Low Latency CommunicationsUUID Universally Unique IdentifierVLR Visitor Location RegisterVoLTE Voice over LTEVRB Virtual Resource BlockWCDMA Wideband Code Division Multiple Access (UMTS)Xn‐C Xn‐Control planeXn‐U Xn‐User planeXnAP Xn Application Protocol

1 Introduction : Career Opportunities in Mobile Communications Networks Space

       You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York; and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat.

      Source: Albert Einstein.

      Gone are the days when mobile phones were considered a luxury; today, it is among our daily necessities. Mobile communications have evolved quickly and revolutionized the way we communicate and have brought people around the globe closer than ever before. At the same time, the mobile telecom industry has witnessed an explosive growth rate over the past many years, offering a wide range of services and products.

      The latest trend is the availability of multitasking smartphones and various apps for different services and capabilities for our day‐to‐day needs. The combination of smartphones and Apps is enabling mobile broadband services to everyone, everywhere, and anytime on the go. This is leading to a growing demand for smartphones along with manifold increase in Internet traffic. The legacy mobile communications network standards such as Global System for Mobile Communication (GSM) (2G), General Packet Radio Service (GPRS) (2.5G), Universal Mobile Telecommunication System (UMTS) (3G), Long‐Term Evolution (LTE) (4G), and the emerging and latest buzzword 5G, along with the growth in the number of mobile subscribers, have created a gap between the demand and supply of skilled mobile communications professionals.

The mobile communications industry is a key driver and offers immense employment opportunities. The advent of the 5G system and network is expected to create and offer more opportunities for various professionals and business owners. Communications solution service providers, network installers, original equipment manufacturers (OEMs), and communications software solution services provider firms are demanding skilled and experienced professionals. In the mobile communications space alone, career opportunities exist across these different verticals and areas. Some of these career opportunities are shown in Figure 1.1.

      The career opportunity areas shown in Figure 1.1 are at a very high level only. Each of the areas shown spans across multiple systems and subsystems. Opportunities exist at an entry‐level or experienced professional level for various job roles such as software developer and maintenance, team leader, project manager, system architect and engineering, site engineer, network engineer, network operation and maintenance, and so on.

      Mobile communications systems and networks are built based on open technical standards, covering a wide spectrum of knowledge areas as illustrated in Figure 1.1. The knowledge areas are spread across the different system engineering areas of mobile communications systems and networks. This book attempts to cover some of those knowledge areas from a practical point of view, so that one can be self‐equipped to start a career in the mobile communications domain.

Figure 1.1 Career opportunities in the mobile communications space.

Part I Network Architectures, Standardization, Protocols, and Functions

      Mobile communications systems and networks based on the GSM/GPRS, UMTS, LTE, and 5G systems and technologies consist of telecommunications infrastructures to provide communications services to mobile users. In this first part of the book, several knowledge areas of legacy mobile communications systems and networks which are based on the GSM/GPRS, UMTS, and LTE technologies as well as 5G systems are covered. The 5G system shall be covered exclusively in Part IV of this book. Because even if a reader is starting a career in LTE, 5G, or the latest, system and network, and as a developer or O&M person, one must know the major key concepts from the legacy GSM/UMTS/LTE networks as well. The network architectures and their protocols; the 3GPP standardization processes; systems engineering; functions such as the network identities, packet encapsulations, and interworking of network aspects of the GSM/GPRS, UMTS, LTE, and 5G system are discussed. This part