LTE Air Interface
With the introduction of LTE came the development of a new radio technology based on OFDMA / SC-FDMA. This course focuses on the LTE Air interface and provides a detailed analysis of the structure and features of the physical layer, as well as the layer 2 and 3 protocols, before explaining how these are used in the operation of the radio link from initial attach, through service delivery and finally mobility. In so doing, both LTE and LTE-Advanced are detailed. In addition, the operation of the X2 interface is also explored, as well as LTE Advanced Relays and Self Organizing Networks.
Section 1 - E-UTRA Introduction
Topic areas covered include:
- E-UTRA Features:
- Radio Access.
- Duplexing Techniques:
- FDD, TDD.
- Modulation and Coding.
- Transmission Bandwidth.
- LTE FFT Sizes.
- Subcarriers and Reference Signals.
- Orthogonal Frequency Division Multiplexing:
- OFDM Symbol Mapping.
- Transmitted Signal.
- Combating Interference in the Time Domain.
- Cyclic Prefix.
- OFDMA:
- OFDM.
- LTE Uplink - Single Carrier - Frequency Division Multiple Access:
- The SC-FDMA Process.
- The E-UTRAN Protocols:
- NAS, RRC, PDCP, RLC, MAC, S1AP and X2AP.
- Evolved Node B:
- Home Evolved Node B.
- UE Capabilities.
Section 2 - E-UTRA Physical Layer
Topic areas covered include:
- LTE Generic Frame Structure:
- Type 1 Radio Frames, Slots and Subframes.
- Type 2 Radio Frames, Slots and Subframes.
- Resource Grid and Resource Blocks:
- Downlink PRB Parameters.
- Uplink PRB Parameters.
- Downlink Channel for Initial Access:
- Downlink Synchronization Signals (FDD).
- Downlink Reference Signals:
- Cell Specific Reference Signals.
- UE Specific Reference Signals.
- The LTE Downlink Physical Channels:
- Broadcast Information.
- PCFICH:
- CFI.
- PDCCH:
- REG, CCE.
- PHICH.
- PDSCH.
- PDSCH Resource Allocation.
- The LTE Uplink Physical Channels:
- Multiplexing of Control Signalling and UL-SCH Data.
- Uplink Data Transmission.
- PUCCH (Physical Uplink Control Channel).
- Uplink Reference Signals:
- Demodulation Reference Signal.
- Sounding Reference Signal.
- PRACH.
- Channel Coding.
- FDD/TDD Timing:
- FDD Operation.
- TDD Operation.
- Timing Advance.
- HARQ Operation.
- RNTI Identities.
- Transmission Modes and MIMO:
- MIMO and Transmission Options:
- SU-MIMO, MU-MIMO.
- Transmit Diversity.
- MIMO.
- Active Antenna Systems.
- CoMP (Coordinated Multi Point).
- CoMP Categories.
- Carrier Aggregation.
Section 3 - LTE RRC
Topic areas covered include:
- Radio Resource Control:
- RRC Messages.
- RRC States.
- System Information:
- Acquisition of SI Messages.
- RRC Connection.
- E-UTRA Radio Bearers:
- Signalling Radio Bearers
- Dedicated Radio Bearers.
- UE Capabilities.
Section 4 - NAS in LTE
Topic areas covered include:
- NAS Control and User Plane:
- Stratums.
- NAS Messages.
- EMM and ECM States:
- EPS Mobility Management States.
- EPS Connection Management States.
Section 5 - PDCP in LTE
Topic areas covered include:
- Packet Data Convergence Protocol:
- PDCP Services.
- PDCP Profiles:
- Compression Standards:
- ROHC.
- PDCP Headers:
- Control Plane PDCP Data PDU for SRBs.
- User Plane PDCP Data PDU - 12bit SN.
- User Plane PDCP Data PDU - 7bit SN.
- PDCP Control PDU - Feedback.
- PDCP Control PDU - Status Report.
- RN User Plane PDCP Data PDU - Integrity Protection.
- PDCP Status Exchange.
Section 6 - RLC in LTE
Topic areas covered include:
- Radio Link Control:
- Transparent Mode.
- Unacknowledged Mode.
- Acknowledged Mode.
- RLC PDUs.
Section 7 - MAC in LTE
Topic areas covered include:
- Medium Access Control:
- Services expected from physical layer.
- LTE Logical and Transport Channels.
- RNTI Identities.
- MAC Headers.
- Random Access Process.
- Buffer Status Reporting:
- BSR Types.
- Power Headroom Reporting:
- PHR Types.
Section 8 - Operational Procedures
Topic areas covered include:
- Initial Procedures:
- Cell Search.
- Cell Selection.
- PLMN Selection.
- Cell Selection.
- Random Access.
- Initial Attach.
- LTE Capabilities.
- Discontinuous Reception (Paging).
- DRX in Active Mode:
- Air Interface Scheduling (VoLTE).
- Improving Coverage with TTI Bundling.
- Voice Scheduling and SPS.
- Security:
- EPS Authentication and Key Agreement.
- Key Distribution in the EPS.
- Security Procedures.
- Algorithms.
- IPSec - Encapsulating Security Payload.
- Power Control:
- Downlink Power Control.
- Uplink Power Control.
- E-UTRA Measurements:
- Measurement Configuration Options.
- Basics of Measurement Objects.
- Basics of Report Configuration.
- LTE Events.
- RRC Measurement Configuration Example.
- Gap Configuration.
- Timing.
- ISR (Idle mode Signalling Reduction):
- TIN Values.
- ISR Activation.
- Feedback Mechanisms:
- Feedback Types.
Section 9 - Air Interface Mobility
Topic areas covered include:
- Air Interface Mobility:
- LTE Cell Planning.
- LTE Measurements:
- RSRP (Reference Signal Received Power).
- RSSI (Received Signal Strength Indicator).
- RSRQ (Reference Signal Received Quality).
- Mobility Functional Architecture:
- eNB.
- MME.
- Tracking Area.
- LTE Idle Mode Mobility:
- LTE Cell Reselection.
- Priority Based Inter-RAT Cell Reselection.
- E-UTRA System Information Messages.
- Reselection to a Higher Priority Frequency or RAT cell.
- Reselection to a Lower Priority Frequency or RAT cell.
- Deleting E-UTRA Priorities.
- Mobility in the LTE Active State.
- Handover Process:
- X2 Handover Request and Response
- RRC Connection Reconfiguration.
- Random Access.
- SN Status Transfer and Status Report.
- Data Forwarding:
- RLC-AM DRBs.
- RLC-UM DRBs.
- SRB Handling.
- S1 Based Handover (Relocation).
Section 10 - X2 Interface Operation
Topic areas covered include:
- The X2 Interface.
- X2 Basic Mobility Procedures:
- X2 Handover Request.
- X2 Handover Request Acknowledge.
- X2 Handover Preparation Failure.
- X2 SN Status Transfer.
- X2 UE Context Release.
- X2 Handover Cancel.
- X2 Load Indication.
- X2 Resource Status Reporting.
- Heterogeneous Networks:
- ICIC (Inter-Cell Interference Coordination).
- eICIC (Enhanced ICIC):
- CRE (Cell Range Extension).
- ABS (Almost Blank Subframes).
- feICIC.
- Cross-Carrier Scheduling.
Section 11 - Relay Nodes
Topic areas covered include:
- Evolution of Relay Nodes.
- RN Terminology.
- Uses of Relay Nodes:
- Range Extension.
- Capacity Boost.
- Indoor Coverage.
- Blind Spot Coverage.
- Architecture:
- Relay Node Start Up Procedure.
- Relay Node Detach Procedure.
- Example of RN Reconfiguration Message.
Section 12 - SON
Topic areas covered include:
- Self Organizing Networks.
- SON Features.
- Automatic Neighbour Relation:
- ANR Procedure.
- Possible ANR Architecture.