LTE Air Interface and Signalling

Did you know that LTE networks using X2 handover can keep VoIP calls almost seamless, while breakthroughs like SK Telecom’s first LTE-Advanced carrier aggregation to 150 Mbps and automated, cloud-based drive testing now let operators roll out and optimize LTE faster, with fewer field resources and significantly better user experience?

Course Overview

The LTE Air Interface and Signalling course by Rcademy is designed to equip RAN engineers, RF engineers, optimization specialists, protocol engineers, signaling specialists, network planning engineers, and system engineers with comprehensive understanding of LTE/E-UTRA air interface architecture, physical layer structure, and radio transmission principles based on OFDMA/SC-FDMA. Participants gain expert-level knowledge of LTE protocol stack layers (Physical, MAC, RLC, PDCP, RRC), frame structure, resource allocation, physical channels, signals, procedures, and detailed signaling flows for registration, connection establishment, bearer setup, mobility, and handover.​

Without specialized LTE air interface training, professionals may struggle to analyze protocol traces, decode air interface messages, diagnose HARQ failures, troubleshoot registration and bearer establishment issues, or optimize handover parameters, limiting their ability to support rapid network deployment and deliver measurable KPI improvements. This comprehensive course provides a structured path to mastery across LTE physical layer processing, Layer 2/3 protocols, RRC signaling, mobility procedures, and systematic troubleshooting, preparing attendees to lead LTE deployment, operations, and optimization initiatives.​

Real-world cases show how SK Telecom rolled out the world’s first commercial LTE-Advanced network in June 2013 deploying carrier aggregation technology combining two 10 MHz carriers to support downlink speeds up to 150 Mbps, enabling 800 MB movie downloads in 43 seconds and expanding coverage to 84 cities at no price premium over standard LTE tariffs.

Studies also show that X2 handover significantly reduces handover latency and packet loss compared to S1-based handover requiring MME participation, with field testing showing X2 handover maintains continuous VoIP quality with minimal interruption while S1 handover introduces measurable packet loss triggering TCP retransmissions (26% due to timeout), though both keep overall quality impairment within acceptable limits.

Take charge of your LTE expertise. Enroll now in the Rcademy LTE Air Interface and Signalling course to master the protocol knowledge and signaling analysis skills that drive successful network deployments.

Who Should Attend?

The LTE Air Interface and Signalling course by Rcademy is ideal for:

• RAN engineers and RF engineers
• Optimization specialists working with LTE networks
• Protocol engineers and signaling specialists
• Network planning and design engineers
• System engineers performing testing and verification
• Technical professionals in hardware/software development
• Operations and maintenance staff
• Integration engineers for LTE network elements
• Performance analysis engineers
• Drive test engineers and field technicians
• Network operations center (NOC) engineers
• Quality assurance engineers for LTE testing
• Research institutes and defense sector professionals
• Wireless engineers transitioning to LTE
• Anyone seeking comprehensive LTE air interface certification

What are the Training Goals?

The main objectives of the LTE Air Interface and Signalling course are to enable professionals to:

• Master comprehensive LTE/E-UTRA air interface architecture, physical layer structure, and radio transmission principles based on OFDMA/SC-FDMA.
• Develop expert-level knowledge of LTE protocol stack layers: Physical (PHY), MAC, RLC, PDCP, and RRC signaling protocols.
• Understand LTE frame structure, resource allocation, physical channels, signals, and procedures for downlink and uplink transmission.
• Analyze detailed LTE signaling flows for registration, connection establishment, bearer setup, mobility, and handover procedures.
• Apply comprehensive knowledge of LTE Layer 2 protocols including MAC scheduling, RLC ARQ, PDCP header compression, and security.
• Execute advanced RRC signaling analysis covering idle mode, connected mode, measurements, and state transitions.
• Troubleshoot LTE air interface issues using protocol trace analysis, message decoding, and systematic problem isolation.
• Design and optimize LTE radio networks with deep understanding of physical layer processing, HARQ, and MIMO techniques.

How Will This Training Course Be Presented?

At Rcademy, the extensive focus is laid on the relevance of the training content to the audience. Thus, content is reviewed and customised as per the professional backgrounds of the audience.

The training framework includes:

• Expert-led lectures by senior LTE and RAN professionals using audio-visual sessions
• Hands-on protocol analysis with Wireshark and LTE trace analysis tools
• Interactive workshops for physical layer processing and frame structure analysis
• Case studies covering SK Telecom LTE-A deployment, X2/S1 handover optimization, and China Mobile TD-LTE
• Practical exercises analyzing registration, attach, bearer establishment, and handover signaling

The theoretical part of training is delivered by an experienced professional from the relevant domain, using audio-visual presentations. This air interface-focused approach ensures LTE professionals translate theory into practical workflows through signaling trace analysis, MAC PDU construction, HARQ failure diagnosis, and systematic troubleshooting.​

This comprehensive certification model ensures participants gain both architectural knowledge and hands-on proficiency to immediately apply LTE protocol expertise in deployment, optimization, and troubleshooting roles.​

Register now to experience a rigorous, hands-on learning journey designed to equip you for leading LTE deployment, optimization, and troubleshooting projects.

Course Syllabus

Module 1: LTE System Overview and Architecture

• Evolution from 3G to LTE/4G and market drivers for LTE deployment.​
• LTE network architecture: E-UTRAN (eNodeB) and EPC (MME, S-GW, P-GW, HSS).​
• LTE interfaces: Uu (air interface), S1, X2, and protocol stacks overview.​
• Key LTE features: all-IP architecture, flat network, and simplified protocol stack.​
• LTE service categories and Quality of Service (QoS) framework.​

Module 2: LTE Air Interface Physical Layer Fundamentals

• OFDMA (Orthogonal Frequency Division Multiple Access) downlink transmission principles.​
• SC-FDMA (Single Carrier FDMA) uplink transmission and PAPR reduction.​
• Frequency domain resource structure: subcarriers, resource elements (RE), resource blocks (RB).​
• Time domain structure: radio frames, subframes, slots, and OFDM symbols.​
• FDD vs. TDD frame structures and duplexing modes.​
• Cyclic Prefix (CP): normal and extended configurations for multipath mitigation.​

Module 3: LTE Physical Channels and Signals

• Downlink physical channels: PDSCH, PDCCH, PHICH, PCFICH, PBCH, PMCH.​
• Uplink physical channels: PUSCH, PUCCH, PRACH.​
• Physical signals: reference signals (CRS, DMRS, CSI-RS, SRS), synchronization signals (PSS, SSS).​
• Channel mapping: transport channels to physical channels mapping.​
• Resource Element mapping and antenna port configurations.​

Module 4: LTE Physical Layer Processing

• Downlink transmission chain: transport block processing, CRC attachment, code block segmentation.​
• Channel coding: Turbo coding for data channels, convolutional and block coding for control.​
• Rate matching and HARQ (Hybrid ARQ) redundancy version generation.​​
• Modulation schemes: QPSK, 16QAM, 64QAM, and adaptive modulation and coding (AMC).​
• Layer mapping and precoding for MIMO spatial multiplexing.​
• Resource element mapping, OFDM signal generation, and IFFT/FFT operations.​
• Uplink transmission processing: SC-FDMA-specific DFT precoding and resource allocation.​

Module 5: LTE MIMO and Advanced Antenna Techniques

• MIMO fundamentals: spatial multiplexing, transmit diversity, and beamforming.​
• LTE transmission modes: TM1 through TM10 and their use cases.​
• Precoding Matrix Indicator (PMI), Rank Indicator (RI), and codebook-based precoding.​
• Channel State Information (CSI) feedback: CQI, PMI, RI reporting.​
• Multi-user MIMO (MU-MIMO) and interference coordination.​

Module 6: LTE Physical Layer Procedures

• Cell search and initial synchronization: PSS/SSS detection and cell ID identification.​
• System information acquisition from PBCH and SI-RNTI on PDSCH.​
• Random Access Procedure: contention-based and non-contention-based RACH.​​
• Power control: uplink and downlink power allocation and adjustment mechanisms.​
• Link adaptation: AMC, HARQ, and scheduling grant interpretation.​
• Timing advance and uplink synchronization procedures.​​

Module 7: LTE MAC Layer Protocol

• MAC layer architecture and functional responsibilities.​​
• Logical channels, transport channels, and their mapping.​​
• MAC PDU structure: headers, subheaders, MAC SDUs, and MAC control elements.​​
• Downlink and uplink scheduling: resource allocation and grant signaling.​​
• HARQ operation: stop-and-wait protocol, synchronous/asynchronous HARQ, ACK/NACK signaling.​​
• BSR (Buffer Status Report) and PHR (Power Headroom Report) procedures.​​
• DRX (Discontinuous Reception) for power saving in idle and connected modes.​
• Random Access Response (RAR) and contention resolution.​​

Module 8: LTE RLC Layer Protocol

• RLC layer architecture and service models: TM, UM, and AM modes.​
• RLC PDU formats and header structures for each mode.​
• Acknowledged Mode (AM) RLC: ARQ operation, polling, status reporting, and retransmissions.​
• RLC segmentation and re-segmentation of SDUs into PDUs.​
• RLC re-establishment during handover and connection reconfiguration.​

Module 9: LTE PDCP Layer Protocol

• PDCP architecture, functions, and protocol data unit formats.​
• Header compression using RoHC (Robust Header Compression) for IP packets.​
• PDCP sequence numbering and in-sequence delivery mechanisms.​
• Security functions: ciphering and integrity protection of user and control plane data.​
• PDCP reordering and retransmission during handovers for lossless mobility.​
• Duplicate detection and discard mechanisms.​

Module 10: LTE RRC Layer Protocol

• RRC protocol overview and role in radio resource management and mobility.​
• RRC states: RRC_IDLE and RRC_CONNECTED state machines and transitions.​
• System Information: MIB, SIB types, scheduling, and content overview.​
• PLMN selection, cell selection, and cell reselection procedures in idle mode.​
• RRC connection establishment, modification, reconfiguration, and release procedures.​
• Radio Bearer establishment: Signaling Radio Bearers (SRB) and Data Radio Bearers (DRB).​
• UE capability information and Feature Group Indicators (FGI).​

Module 11: LTE Measurement and Mobility Procedures

• Measurement configuration and control via RRC signaling.​
• Intra-frequency, inter-frequency, and inter-RAT measurements.​
• Measurement reporting: periodic and event-triggered reports (A1-A6, B1-B2 events).​
• Handover procedures: X2-based and S1-based handovers.​
• Intra-LTE handover call flows and signaling sequences.​
• Inter-RAT handovers: LTE to UMTS/GSM and vice versa.​

Module 12: LTE Connection Management and Session Procedures

• Attach procedure and default EPS bearer establishment.​
• Tracking Area Update (TAU) and mobility management.​
• Paging procedures and idle mode mobility.​
• Service Request procedure for transition from idle to connected mode.​
• Dedicated bearer establishment: network-initiated and UE-initiated procedures.​
• Bearer modification and release procedures.​

Module 13: LTE NAS (Non-Access Stratum) Signaling

• NAS protocol architecture and EMM/ESM sub-layers.​
• EMM (EPS Mobility Management) states and procedures: attach, detach, TAU.​
• ESM (EPS Session Management) procedures: PDN connectivity, bearer resource management.​
• NAS security: authentication, integrity protection, and ciphering.​
• NAS message structure and information elements.​

Module 14: LTE S1 Interface Signaling

• S1-MME (control plane) and S1-U (user plane) interface architectures.​
• S1AP protocol and message categories: management, bearer, mobility, paging.​
• Initial Context Setup and E-RAB establishment procedures.​
• S1 handover signaling and MME relocation scenarios.​
• S1 interface troubleshooting and common signaling issues.​

Module 15: LTE X2 Interface Signaling

• X2 interface architecture and protocol structure: X2AP and X2-U.​
• X2 setup procedures and neighbor relation management.​
• X2-based handover signaling flows and optimization benefits.​
• Load management and interference coordination over X2.​
• UE context transfer and data forwarding during X2 handover.​

Module 16: LTE-Advanced Features

• Carrier Aggregation (CA): intra-band and inter-band configurations.​
• Enhanced MIMO: 8×8 downlink and 4×4 uplink MIMO capabilities.​
• CoMP (Coordinated Multi-Point) transmission and reception.​
• Relay nodes and heterogeneous network (HetNet) deployments.​
• Enhanced ICIC (eICIC) and FeICIC for interference management.​

Module 17: LTE Security Architecture

• LTE security framework and security domains.​
• Authentication and Key Agreement (AKA) procedures.​
• Key hierarchy: KASME, KNASenc, KNASint, KRRCenc, KRRCint, KUPenc.​
• Ciphering and integrity protection algorithms.​
• Security mode command and completion procedures.​

Module 18: LTE QoS and Bearer Management

• EPS bearer concept: default and dedicated bearers.​
• QCI (QoS Class Identifier) and bearer QoS parameters: GBR, MBR, ARP.​
• AMBR (Aggregate Maximum Bit Rate): UE-AMBR and APN-AMBR.​
• Traffic Flow Templates (TFT) and packet filtering.​
• Policy and Charging Control (PCC) architecture integration.​

Module 19: LTE Signaling Trace Analysis and Troubleshooting

• Protocol analyzer tools and trace collection methodologies.​
• Decoding and interpreting LTE air interface messages (RRC, MAC, RLC, PDCP).​
• Analyzing registration, attach, and bearer establishment call flows.​
• Handover and mobility trace analysis for optimization.​
• Common LTE signaling issues and root cause analysis techniques.​
• HARQ failure analysis and retransmission behavior diagnosis.​

Module 20: Practical Labs and Case Studies

• Hands-on: LTE physical layer processing simulation and resource mapping exercises.​
• Hands-on: MAC PDU construction and scheduling grant interpretation.​​
• Hands-on: RRC connection establishment trace analysis using Wireshark/NetX.​
• Hands-on: LTE attach procedure end-to-end signaling flow analysis.​
• Hands-on: X2 handover signaling analysis and troubleshooting exercises.​
• Case studies: real-world LTE deployment challenges, optimization, and troubleshooting scenarios.

Training Impact

The impact of LTE Air Interface and Signalling training is visible in how operators deployed the world’s first commercial LTE networks, achieved breakthrough LTE-Advanced speeds through carrier aggregation, and executed massive TD-LTE rollouts requiring deep protocol expertise.​

SK Telecom – World’s First Commercial LTE-Advanced Deployment with Carrier Aggregation

Implementation: SK Telecom, South Korea’s leading mobile operator, rolled out the world’s first commercial LTE-Advanced network in June 2013, deploying carrier aggregation technology ahead of all global competitors. The operator combined two 10 MHz carriers to support downlink data speeds up to 150 Mbps twice as fast as standard LTE enabling subscribers to download an 800 MB movie in just 43 seconds and enhancing customer satisfaction in network quality. SK Telecom launched LTE-A service initially in the Seoul area and central cities of Gyeonggi-do and Chungcheong-do with plans to expand coverage to 84 cities across South Korea, offering the advanced service at no price premium over existing LTE tariffs to drive rapid adoption. The deployment required 200,000 Samsung Galaxy S4 LTE-A devices equipped with Qualcomm’s Snapdragon 800 processor supporting 2.3 GHz quad-core CPUs, with plans to expand the LTE-A device lineup to seven smartphones by year’s end.​

Results: SK Telecom’s long-term roadmap included aggregating two 20 MHz component carriers by 2015 for peak downlink speeds up to 300 Mbps, enabling three-carrier aggregation by 2016 along with uplink CA, and ultimately supporting up to five 20 MHz carriers under LTE-Advanced standards. In addition to CA, SK Telecom deployed coordinated multipoint (CoMP) transmission and planned to implement Enhanced Inter-Cell Interference Coordination (eICIC) in 2014 to further optimize network performance. The deployment demonstrated how comprehensive understanding of LTE-Advanced air interface features including physical layer CA resource mapping, MAC scheduling across aggregated carriers, and RRC signaling for component carrier configuration is essential for successful deployment and directly reflects the expertise developed through advanced LTE training.​

TeliaSonera – World’s First Commercial LTE Network Deployment in Stockholm and Oslo

Implementation: TeliaSonera, the pan-Nordic telecommunications operator, achieved a major milestone in December 2009 by becoming the first operator in the world to switch on commercial LTE networks, launching simultaneously in Stockholm, Sweden, and Oslo, Norway. Both networks utilized 2.6 GHz bandwidth that TeliaSonera acquired in recent spectrum auctions, with the operator claiming maximum speeds of 100 Mbps ten times faster than its Turbo-3G (HSPA) network though live tests revealed actual speeds were significantly lower in early deployment. TeliaSonera committed to expand the Swedish network into 25 cities by 2010 and an additional four cities in Norway, while also securing LTE licenses in Finland (where pilots had already started) and planning spectrum bids in Denmark and the Baltic region (Estonia’s EMT, Lithuania’s Omnitel, and Latvia’s LMT). Huawei partnered with TeliaSonera/NetCom to achieve the world’s first mobile broadband internet connection over a live commercial LTE network on June 4, 2009, in Oslo, with TeliaSonera’s project manager receiving and replying to the world’s first email sent over a commercial LTE network, a moment the operator recorded and uploaded to YouTube for publicity.​

Results: TeliaSonera also formed a 50:50 joint venture with Tele2 called Net4Mobility targeting 99% population coverage across Sweden by 2013 with speeds up to 150 Mbps in urban areas, an extremely aggressive target demonstrating the operator’s commitment to LTE deployment. This pioneering deployment required deep expertise in LTE air interface fundamentals including OFDMA physical layer processing, frame structure configuration, cell search and synchronization procedures, RRC connection establishment, and S1 interface signaling exactly the comprehensive protocol and signaling knowledge taught in advanced LTE training programs. Additionally, field testing of VoIP over LTE in TeliaSonera Finland’s live production network demonstrated that X2 handover (direct eNodeB-to-eNodeB coordination) significantly reduced handover latency and packet loss compared to S1-based handover, with 95% of X2 handover cases showing the device disconnected for under 50 milliseconds, maintaining continuous VoIP quality with minimal interruption audible to end users.

China Mobile – Massive TD-LTE Deployment Supporting 500+ Million LTE Subscribers

Implementation: China Mobile, the world’s largest mobile operator, launched commercial TD-LTE (Time Division LTE) services on December 18, 2013, initially in Beijing, Guangzhou, and Chongqing, with Shanghai following shortly after, deploying the service across 130 MHz of spectrum in the 1880-1900 MHz, 2320-2370 MHz, and 2575-2635 MHz bands allocated by China’s government. The $7 billion TD-LTE deployment involved major infrastructure vendors including Ericsson, Nokia Solutions and Networks, Alcatel-Lucent, Huawei, and ZTE, with NSN securing 11% of the total contract as the largest non-Chinese vendor share. China Mobile’s TD-LTE deployment addressed increasing bandwidth demands from subscribers in dense urban areas by leveraging unpaired spectrum to allow downlink and uplink traffic to travel bidirectionally on the same frequency band, with network solutions optimized for Chinese subscribers’ traffic habits favoring mobile video downloads. The operator worked with Apple to launch iPhone models compatible with TD-LTE services in the 2570-2620 MHz, 1880-1920 MHz, and 2300-2400 MHz bands, bringing the popular smartphone to China Mobile’s subscriber base for the first time after rivals China Unicom and China Telecom had already offered Apple products on their GSM and CDMA-based networks.​

Results: This massive deployment required extensive expertise in LTE TDD frame structure (different from FDD), special subframe configurations, uplink-downlink reconfiguration, TD-LTE-specific physical channels and procedures, as well as MAC layer scheduling adapted for asymmetric traffic patterns demonstrating how comprehensive LTE air interface and signaling training prepares engineers for real-world large-scale network deployments across diverse operator environments. China Mobile’s TD-LTE deployment enabled the operator to serve hundreds of millions of LTE subscribers, with the network designed to support China’s unique spectrum allocation and traffic patterns while maintaining compatibility with global LTE device ecosystems through careful protocol implementation and testing.

Be inspired by how SK Telecom, TeliaSonera, and China Mobile built world-leading LTE networks at scale. Join the Rcademy LTE Air Interface and Signalling course to gain the protocol and optimization skills that power high-performance LTE deployments.