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Slides dayone-121110052003-phpapp02

  1. 1. Arief Hamdani Gunawan 1.1. Introduction to LTEIntroduction to LTE 2.2. OFDMAOFDMA 3.3. SCSC--FDMAFDMA 4.4. LTE Network and ProtocolLTE Network and Protocol 5. LTE Radio Procedures5. LTE Radio Procedures 6. LTE Uplink Physical Channels and6. LTE Uplink Physical Channels and SignalsSignals 7. LTE Mobility7. LTE Mobility 8. LTE Test and Measurement8. LTE Test and Measurement
  2. 2. Arief Hamdani Gunawan
  3. 3. Session 1: Introduction to LTE •Motivation•Motivation •Requirements •Evolution of UMTS FDD and TDD •LTE Technology Basics •LTE Key Parameters •LTE Frequency Bands
  4. 4. Motivation: LTE background story the early days Work on LTE was initiated as a 3GPP release 7 study item “Evolved UTRA and UTRAN” in December 2004: “With enhancements such as HSDPA and Enhanced Uplink, the 3GPP radio-access technology will be highly competitive for several years. However, to ensure competitivenessHowever, to ensure competitiveness in an even longer time frame, i.e. for the next 10 years and beyond, a long term evolution of the 3GPP radio- access technology needs to be considered.” • Basic drivers for LTE have been: – Reduced latency – Higher user data rates – Improved system capacity and coverage – Cost-reduction.
  5. 5. Major requirements for LTE identified during study item phase in 3GPP • Higher peak data rates: 100 Mbps (downlink) and 50 Mbps (uplink) • Improved spectrum efficiency: 2-4 times better compared to 3GPP release 6 • Improved latency: – Radio access network latency (user plane UE – RNC - UE) below 10 ms – Significantly reduced control plane latency • Support of scalable bandwidth: 1.4, 3, 5, 10, 15, 20 MHz• Support of scalable bandwidth: 1.4, 3, 5, 10, 15, 20 MHz • Support of paired and unpaired spectrum (FDD and TDD mode) • Support for interworking with legacy networks • Cost-efficiency: – Reduced CApital and OPerational EXpenditures (CAPEX, OPEX) including backhaul – Cost-effective migration from legacy networks • A detailed summary of requirements has been captured in 3GPP TR 25.913 „Requirements for Evolved UTRA (E-UTRA) and Evolved UTRAN (E- UTRAN)”.
  6. 6. Evolution of UMTS FDD and TDD driven by data rate and latency requirements Note: •High-Speed Downlink Packet Access (HSDPA, also known as High-Speed Data Packet Access) •High-Speed Uplink Packet Access (HSUPA) •High Speed Packet Access (HSPA)
  7. 7. 3GPP Systems Building on Releases
  8. 8. Release 99: Key Features • Functional Freeze: Dec 1999 – CS and PS – R99 Radio Bearers – Multimedia Messaging Service (MMS) – Location Services • Functional Freeze: March 2000 – Basic 3.84 Mcps W-CDMA (FDD & TDD) • Enhancements to GSM data (EDGE). • Provides support for GSM/EDGE/GPRS/WCDMA radio-access networks. • Majority of deployments today are based on Release 99.
  9. 9. Release 4: Key Features • Functional Freeze: March 2001 – Enhancements 1.28 Mcps TDD (aka TD-SCDMA). – Multimedia messaging support. – First steps toward using IP transport in the core network. Megachips per second (Mcps) is a measure of the speed with which encoding elements, called chips (not to be confused with microchips), are generated in Direct Sequence Spread Spectrum (DSSS) signals. This speed is also known as the chipping rate. A speed of 1 Mcps is equivalent to 1,000,000, or 106, chips per second. Typical chipping rates in third-generation (3G) wireless systems are on the order of several million chips per second. For example, in Wideband Code-Division Multiple Access (W-CDMA) systems, the standard rate is 3.84 Mcps.
  10. 10. Release 5: Key Features • Functional Freeze: June 2002 – HSDPA – IMS: First phase of Internet Protocol Multimedia Subsystem (IMS). – Adaptive Multi-Rate - Wideband (AMR-WB) Speech – Full ability to use IP-based transport instead of just Asynchronous Transfer Mode (ATM) in the core network.Transfer Mode (ATM) in the core network. Adaptive Multi-Rate Wideband (AMR-WB) is a patented speech coding standard developed based on Adaptive Multi-Rate encoding, using similar methodology as Algebraic Code Excited Linear Prediction (ACELP). AMR-WB provides improved speech quality due to a wider speech bandwidth of 50–7000 Hz compared to narrowband speech coders which in general are optimized for POTS wireline quality of 300–3400 Hz. AMR-WB was developed by Nokia and VoiceAge and it was first specified by 3GPP. AMR-WB is codified as G.722.2, an ITU-T standard speech codec, formally known as Wideband coding of speech at around 16 kbit/s using Adaptive Multi-Rate Wideband (AMR-WB). G.722.2 AMR-WB is the same codec as the 3GPP AMR-WB. The corresponding 3GPP specifications are TS 26.190 for the speech codec and TS 26.194 for the Voice Activity Detector.
  11. 11. 3GPP architecture evolution towards flat architecture GGSN Release 6 GGSN Release 7 Direct Tunnel GGSN Release 7 Direct Tunnel and RNC in NB Release 8 SAE and LTE SAE GW SGSN RNC NB SGSN RNC NB SGSN RNC NB MME eNB Control Plane User Plane
  12. 12. Release 6: Key Features • Functional Freeze: March 2005 – HSUPA (E-DCH) / Enhanced Uplink – Enhanced multimedia support through Multimedia Broadcast/Multicast Services (MBMS).Multimedia Broadcast/Multicast Services (MBMS). – WLAN-UMTS Internetworking: Wireless Local Area Network (WLAN) integration option – Performance specifications for advanced receivers. – IMS enhancements. Initial VoIP capability.
  13. 13. Release 7: Key Features • Functional Freeze: Dec 2007 – Evolved EDGE. – Specifies HSPA+ – Radio enhancements to HSPA include 64 Quadrature Amplitude Modulation (QAM) in the downlink DL and 16 QAM in the uplink. – LTE and SAE Feasibility Study– LTE and SAE Feasibility Study – DL MIMO, – IMS – Performance enhancements, improved spectral efficiency, increased capacity, and better resistance to interference. – Continuous Packet Connectivity (CPC) enables efficient “always-on” service and enhanced uplink UL VoIP capacity, as well as reductions in call set-up delay for Push-to-Talk Over Cellular (PoC). – Optimization of MBMS capabilities through the multicast/broadcast, single-frequency network (MBSFN) function.
  14. 14. LTE Release 8: Key Features • Functional Freeze: Dec 2008 – Further HSPA improvements / HSPA Evolution, simultaneous use of MIMO and 64 QAM. – Includes dual-carrier HSPA (DC-HSPA) where in two WCDMA radio channels can be combined fortwo WCDMA radio channels can be combined for a doubling of throughput performance. – LTE work item – OFOMA / SC-FDMA air interface – SAE work item – new IP core network – Specifies OFDMA-based 3GPP LTE. – Defines EPC.
  15. 15. LTE Release 8: Key Features • High spectral efficiency – OFDM in Downlink • Robust against multipath interference • High affinity to advanced techniques – Frequency domain channel-dependent scheduling – MIMO – DFTS-OFDM(“Single-Carrier FDMA”) in Uplink • Low PAPR User orthogonality in frequency domain DFTS-OFDM • User orthogonality in frequency domain – Multi-antenna application • Very low latency – Short setup time & Short transfer delay – Short HO latency and interruption time • Short TTI • RRC procedure • Simple RRC states • Support of variable bandwidth – 1.4, 3, 5, 10, 15 and 20 MHz DFTS-OFDM: DFT-spread OFDM. DFT: Discrete Fourier Transform. DFT-spread OFDM (DFTS-OFDM) is a transmission scheme that can combine the desired properties for uplink transmission i.e. : • Small variations in the instantaneous power of the transmitted signal (‘single carrier’ property). • Possibility for low-complexity high-quality equalization in the frequency domain. • Possibility for FDMA with flexible bandwidth assignment. Due to these properties, DFTS-OFDM has been selected as the uplink transmission scheme for LTE, which is the long-term 3G evolution.
  16. 16. LTE-Advanced: Key Requirements LTE-Advanced shall be deployed as an evolution of LTE Release 8 and on new bands. LTE-Advanced shall be backwards compatible with LTE Release 8 Smooth and flexible system migration from Rel-8 LTE to LTE-Advanced LTE-Advanced backward compatibility with LTE Rel-8 LTE Rel-8 cell LTE Rel-8 terminal LTE-Advanced terminal LTE-Advanced cell LTE Rel-8 terminal LTE-Advanced terminal LTE-Advanced backward compatibility with LTE Rel-8 An LTE-Advanced terminal can work in an LTE Rel-8 cell An LTE Rel-8 terminal can work in an LTE-Advanced cell LTE-Advanced contains all features of LTE Rel-8&9 and additional features for further evolution
  17. 17. LTE Release 9: Key Features • Small enhancements from LTE Release 8 mainly for higher layer – HeNB (Home eNode B) • HeNB Access Mode – Rel-8: Closed Access Mode – Rel-9: Open and Hybrid Mode • HeNB Mobility between HeNB and macro – Rel-8: Out-bound HO – Rel-9: in-bound and inter-CSG HO– Rel-9: in-bound and inter-CSG HO – SON (self-organizing networks) • Rel-8: Self configuration, Basic self-optimization • Rel-9: RACH optimization, etc – MBMS (Multimedia Broadcast Multicast Service) • Rel-8: Radio physical layer specs • Rel-9: Radio higher layer and NW interface specs – LCS (Location Services) • Rel-8: U-Plane solutions • Rel-9: C-Plane solutions, e.g. OTDOA
  18. 18. LTE Release 9: Key Features • HSPA and LTE enhancements including – HSPA dual-carrier operation in combination with MIMO, – EPC enhancements,– EPC enhancements, – femtocell support, – support for regulatory features such as emergency user-equipment positioning and Commercial Mobile Alert System (CMAS), and – evolution of IMS architecture.
  19. 19. 1999 Release 99 Release 4 Release 5 Release 6 1.28Mcps TDD HSDPA W-CDMA HSUPA, MBMS LTE-Advanced: Motivation 2011 3GPP aligned to ITU-R IMT process Allows Coordinated approach to WRC 3GPP Releases evolve to meet: • Future Requirements for IMT • Future operator and end-user Release 7 HSPA+ (MIMO, HOM etc.) Release 8 LTE Release 9 Release 10 LTE enhancements Release 11+ ITU-R M.1457 IMT-2000 Recommendation ITU-R M.[IMT.RSPEC] IMT-Advanced Recommendation LTE-Advanced • Future operator and end-user requirements Further LTE enhancements 3 Gbps 64QA M 8x8 MIMO 100MHz BW
  20. 20. LTE Release 10: Key Features Support of Wider Bandwidth(Carrier Aggregation) • Use of multiple component carriers(CC) to extend bandwidth up to 100 MHz • Common physical layer parameters between component carrier and LTE Rel-8 carrier Improvement of peak data rate, backward compatibility with LTE Rel-8 Advanced MIMO techniques • Extension to up to 8-layer transmission in downlink • Introduction of single-user MIMO up to 4-layer transmission in uplink • Enhancements of multi-user MIMO Improvement of peak data rate and capacity Heterogeneous network and eICIC(enhanced Inter-Cell Interference 100 MHz f CC Heterogeneous network and eICIC(enhanced Inter-Cell Interference Coordination) • Interference coordination for overlaid deployment of cells with different Tx power Improvement of cell-edge throughput and coverage Relay • Type 1 relay supports radio backhaul and creates a separate cell and appear as Rel. 8 LTE eNB to Rel. 8 LTE UEs Improvement of coverage and flexibility of service area extension Coordinated Multi-Point transmission and reception (CoMP) • Support of multi-cell transmission and reception Improvement of cell-edge throughput and coverage LTE-Advanced meeting the requirements set by ITU’s IMT-Advanced project. Also includes quad-carrier operation for HSPA+.
  21. 21. Spectrum Explosion in 3GPP Recently standardized (Sep. 2011) • UMTS/LTE 3500MHz • Extending 850 MHz Upper Band (814 – 849 MHz) Spectrum to be standardized by Sep. 2012 • LTE-Advanced Carrier Aggregation of Band 3 and Band 7 • LTE Advanced Carrier Aggregation of Band 4 and Band 17 • LTE Advanced Carrier Aggregation of Band 4 and Band 13 • LTE Advanced Carrier Aggregation of Band 4 and Band 12 • LTE Advanced Carrier Aggregation of Band 5 and Band 12 E-UTRA operating bands in 3GPP TS 36.101 • LTE Advanced Carrier Aggregation of Band 5 and Band 12 • LTE Advanced Carrier Aggregation of Band 20 and Band 7 • LTE Advanced Carrier Aggregation Band 2 and Band 17 • LTE Advanced Carrier Aggregation Band 4 and Band 5 • LTE Advanced Carrier Aggregation Band 5 and Band 17 • LTE Advanced Carrier Aggregation in Band 41 • LTE Advanced Carrier Aggregation in Band 38 • LTE Downlink FDD 716-728MHz • LTE E850 - Lower Band for Region 2 (non-US) • LTE for 700 MHz digital dividend • Study on Extending 850MHz • Study on Interference analysis between 800~900 MHz bands • Study on UMTS/LTE in 900 MHz band
  22. 22. E-UTRA operating bands Duplex Mode: FDD
  23. 23. E-UTRA operating bands Duplex Mode: TDD
  24. 24. 3GPP TS 36.101 Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) radio transmission and reception
  25. 25. 3GPP TS 36.101 Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) radio transmission and reception
  26. 26. 120MHz separation duplex FDD Uplink FDD DownlinkTDD 2500 26902570 2620 MHz The 2.6GHz band Capacity • Unique new band internationally harmonized • Benefits of future economies of scale • Capability to offer sufficient bandwidth per operator (20+20MHz) • Avoid prejudicial interference, optimizing the spectrum use, through clear definition of FDD (70+70MHz) and TDD (50MHz) spectrum blocks
  27. 27. 700MHz band Coverage 45 45105 3 698 806 703 748 758 803 MHz Coverage • Perfect fit to majority of countries in the region • The alignment with Asia-Pacific permits the creation of a big market (economies of scale, availability of terminals, etc.) • Offer 2 continuous blocks of 45+45MHz (spectrum optimization, flexibility on license process, better data transmission performance than US 700); • Tool to bring the mobile broadband to rural and low density population areas
  28. 28. 2.6GHz + 700MHz • Ideal combination for – Coverage – Capacity – Convergence – Device availability– Device availability – Roaming • Convergence for countries with the legacy US band plan (850/1900MHz) and the legacy European band plan (900/1800MHz) • Note: no plans/proposals in 3GPP for LTE in 450Mhz band
  29. 29. LTE Release 11: Key Features (Dec/2012) Further Downlink MIMO enhancements for LTE-Advanced Addressing low-power modes, relay backhaul scenarios, and certain practical antenna configurations Provision of low-cost M2M UEs based on LTE Studying LTE Coverage Enhancements Network-Based Positioning Support for LTE Further Self Optimizing Networks (SON) EnhancementsFurther Self Optimizing Networks (SON) Enhancements Mobility Robustness Optimisation (MRO) enhancements Addressing Inter-RAT ping-pong scenarios Carrier based HetNet Interference co-ordination for LTE Carriers in same or different bands in HetNet environments with mixture of different BTS types Enhancements to Relays, Mobile Relay for LTE RF core requirements for relays Mobile relay: mounted on a vehicle wirelessly connected to the macro cells Interworking - 3GPP EPS and fixed BB accesses, M2M, Non voice emergency communications, 8 carrier HSDPA, Uplink MIMO study
  30. 30. RAN Release 11 Priorities • Short term prioritization for the end of 2011, between RAN#53 and RAN#54 • The next Plenary - RAN#54 (Dec. 2011) – will discuss priorities beyond March 2012 H S P A Priority Work Items; Latest WID/SID RAN Working Group Core part: Uplink Transmit Diversity for HSPA – Closed Loop RP-110374 RAN 1 New WI: Four Branch MIMO transmission for HSDPA RP-111393 RAN 1 Core Part: eight carrier HSDPA RP-101419 RAN 1 Core part: Further Enhancements to CELL_FACH RP-111321 RAN 2 New WI: HSDPA Multiflow Data Transmission RP-111375 RAN 2 Proposed WID: Single Radio Voice Call Continuity from UTRAN/GERAN to E-UTRAN/HSPA RP-111334 RAN 3 Core part: Non-contiguous 4C-HSDPA operation RP-110416 RAN 4 New SID proposal: Introduction of Hand phantoms for UE OTA antenna testing RP-111380 RAN 4 Core part: Uplink Transmit Diversity for HSPA – Open Loop RP-110374 RAN 4 UE Over the Air (Antenna) conformance testing methodology- Laptop Mounted Equipment Free Space test RP-111381 RAN 4
  31. 31. RAN Release 11 Priorities L T E Priority Work Items; Latest WID/SID RAN Working Group WI/SI Coordinated Multi-Point Operation for LTE RP-111365 RAN 1 Core part: LTE Carrier Aggregation Enhancements RP-111115 RAN 1 Core part: Further Enhanced Non CA-based ICIC for LTE RP-111369 RAN 1 Study on further Downlink MIMO enhancements for LTE-Advanced RP-111366 RAN 1 Provision of low-cost MTC UEs based on LTE RP-111112 RAN 1 Proposed SI on LTE Coverage Enhancements RP-111359 RAN 1 Core part: LTE RAN Enhancements for Diverse Data Applications RP-111372 RAN 2 Study on HetNet mobility enhancements for LTE RP-110709 RAN 2 Enhancement of Minimization of Drive Tests for E-UTRAN and UTRAN RP-111361 RAN 2 New WI: Signalling and procedure for interference avoidance for in-device coexistence RP-111355 RAN 2New WI: Signalling and procedure for interference avoidance for in-device coexistence RP-111355 RAN 2 New WI proposal: RAN overload control for Machine-Type Communications RP-111373 RAN 2 Core part: Service continuity and location information for MBMS for LTE RP-111374 RAN 2 Core Part: Network-Based Positioning Support for LTE RP-101446 RAN 2 Further Self Optimizing Networks (SON) Enhancements RP-111328 RAN 3 Core part: Carrier based HetNet ICIC for LTE RP-111111 RAN 3 New WI: Network Energy Saving for E-UTRAN RP-111376 RAN 3 Proposed WID: LIPA Mobility and SIPTO at the Local Network RAN Completion RP-111367 RAN 3 Study on further enhancements for HNB and HeNB RP-110456 RAN 3 New SI: Mobile Relay for E-UTRA RP-111377 RAN 3 Enhanced performance requirement for LTE UE RP-111378 RAN 4 New SI: Study of RF and EMC Requirements for Active Antenna Array System (AAS) Base Station RP-111349 RAN 4 Study on Measurement of Radiated Performance for MIMO and multi-antenna reception for HSPA and LTE terminals RP-090352 RAN 4 New WI: E-UTRA medium range and MSR medium range/local area BS class requirements RP-111383 RAN 4 Core part: Relays for LTE (part 2) RP-110914 RAN 4 Study on Inclusion of RF Pattern Matching Technologies as a positioning method in the E-UTRAN RP-110385 RAN 4
  32. 32. Plans for LTE-A Release-12 • 3GPP workshop to be held June/2012 – Main themes and strategic directions to be set, e.g.: • Extreme capacity needs and spectrum efficiency (‘challenge Shannon’ • Flexibility, efficient handling of smartphone diversity • Offloading to unlicensed radio technologies• Offloading to unlicensed radio technologies • Power efficiency • Prime areas of interest, e.g.: – More optimized small cell deployments – Carrier Aggregation Enhancements (inter-site, LTE/HSPA) – Cognitive radio aspects – SON and MDT enhancements – Local Area optimizations
  33. 33. LTE Key Parameters
  34. 34. Session 2: OFDMA •OFDM and OFDMA•OFDM and OFDMA •LTE Downlink •OFDMA time-frequency multiplexing •LTE Spectrum Flexibility •LTE Frame Structure type 1 (FDD) •LTE Frame Structure type 2(TDD)
  35. 35. OFDM • Single Carrier Transmission (e.g. WCDMA) • Orthogonal Frequency Division Multiplexing
  36. 36. OFDM Concept: Mengapa OFDM • Sinyal OFDM (Orthogonal Frequency Division Multiplexing) dapat mendukung kondisi NLOS (Non Line of Sight) dengan mempertahankan efisiensi spektral yang tinggi dan memaksimalkan spektrum 36 spektral yang tinggi dan memaksimalkan spektrum yang tersedia. • Mendukung lingkungan propagasi multi-path. • Scalable bandwidth: menyediakan fleksibilitas dan potensial mengurangi CAPEX (capital expense).
  37. 37. OFDM Concept: NLOS Performance 37
  38. 38. OFDM Concept: Mutipath Propagation 38 • Sinyal-sinyal multipath datang pada waktu yang berbeda dengan amplitudo dan pergeseran fasa yang berbeda, yang menyebabkan pelemahan dan penguatan daya sinyal yang diterima. • Propagasi multipath berpengaruh terhadap performansi link dan coverage. • Selubung (envelop) sinyal Rx berfluktuasi secara acak.
  39. 39. OFDM Concept: FFT 39 • Multi-carrier modulation/multiplexing technique • Available bandwidth is divided into several subchannels • Data is serial-to-parallel converted • Symbols are transmitted on different subcarriers
  40. 40. OFDM Concept: IFFT 40 Basic ideas valid for various multicarrier techniques: • OFDM: Orthogonal Frequency Division Multiplexing • OFDMA: Orthogonal Frequency Division Multiple Access
  41. 41. OFDM Concept: Single-Carrier Vs. OFDM 41 Single-Carrier Mode: • Serial Symbol Stream Used to Modulate a Single Wideband Carrier • Serial Datastream Converted to Symbols (Each Symbol Can Represented 1 or More Data Bits) OFDM Mode: • Each Symbol Used to Modulate a Separate Sub-Carrier
  42. 42. OFDM Concept: Single-Carrier Vs. OFDM 42 Single-Carrier Mode OFDM Mode • Dotted Area Represents Transmitted Spectrum • Solid Area Represents Receiver Input • OFDM mengatasi delay spread, multipath dan ISI (Inter Symbol Interference) secara efisien sehingga dapat meningkatkan throughput data rate yang lebih tinggi. • Memudahkan ekualisasi kanal terhadap sub-carrier OFDM individual, dibandingkan terhadap sinyal single-carrier yang memerlukan teknik ekualisasi adaptif lebih kompleks.
  43. 43. OFDM Concept: Motivation for Multi-carrier Approaches • Multi-carrier transmission offers various advantagesadvantages over traditional single carrier approaches: – Highly scalable – Simplified equalizer design in the frequency domain, also in cases of large delay spread – High spectrum density 43 – High spectrum density – Simplified the usage of MIMO – Good granularity to control user data rates – Robustness against timing errors •• WeaknessWeakness of multi-carrier systems: – Increased peak to average power ratio (PAPR) – Impairments due to impulsive noise – Impairments due to frequency errors
  44. 44. OFDM Concept: Peak to Average Power Ratio (PAPR) 44 • PAPR merupakan ukuran dari fluktuasi tepat sebelum amplifier. • PAPR sinyal hasil dari mapping PSK base band sebesar 0 dB karena semua symbol mempunyai daya yang sama. • Tetapi setelah dilakukan proses IDFT/IFFT, hasil superposisi dari dua atau lebih subcarrier dapat menghasilkan variasi daya dengan nilai peak yang besar. • Hal ini disebabkan oleh modulasi masing-masing subcarrier dengan frekuensi yang berbeda sehingga apabila beberapa subcarrier mempunyai fasa yang koheren, akan muncul amplituda dengan level yang jauh lebih besar dari daya sinyalnya.
  45. 45. OFDM Concept: Peak to Average Power Ratio (PAPR) 45 • Nilai PAPR yang besar pada OFDM membutuhkan amplifier dengan dynamic range yang lebar untuk mengakomodasi amplitudo sinyal. • Jika hal ini tidak terpenuhi maka akan terjadi distorsi linear yang menyebabkan subcarrier menjadi tidak lagi ortogonal dan pada akhirnya menurunkan performansi OFDM.
  46. 46. Tipe Sub-Carrier OFDM 46 Data Sub-carriers • Membawa simbol BPSK, QPSK, 16QAM, 64QAM Pilot Sub-carriers • Untuk memudahkan estimasi kanal dan demodulasi koheren pada receiver. Null Subcarrier • Guard Sub-carriers • DC Sub-carrier
  47. 47. Guard Interval (Cyclic Prefix) 47 • Untuk mengatasi multipath delay spread • Guard Interval (cyclic prefix) : 1/4, 1/8, 1/16 or 1/32
  48. 48. OFDM Transceiver 48
  49. 49. OFDM & OFDMA OFDM • Semua subcarrier dialokasikan untuk satu user • Misal : 802.16-2004 OFDMA • Subcarrier dialokasikan secara fleksibel untuk banyak user tergantung pada kondisi radio. • Misal : 802.16e-2005 dan 802.16m 49
  50. 50. OFDM Parameters used in WiMAX 50
  51. 51. Difference between OFDM and OFDMA • OFDM allocates users in time domain only • OFDMA allocates users in time and frequency domain
  52. 52. OFDMA time-frequency multiplexing
  53. 53. LTE Downlink Physical Layer Design: Physical Resource The physical resource can be seen as a time-frequency grid 53 • LTE uses OFDM (Orthogonal Frequency Division Multiplexing) as its radio technology in downlink • In the uplink LTE uses a pre=coded version of OFDM, SC-FDMA (Single Carrier Frequency Division Multiple Access) to reduced power consumption
  54. 54. LTE Downlink Resource Grid 54 • Suatu RB (resource block) terdiri dari 12 subcarrier pada suatu durasi slot 0.5 ms. • Satu subcarrier mempunyai BW 15 kHz, sehingga menjadi 180 kHz per RB.
  55. 55. Parameters for DL generic frame structure 55 Bandwidth (MHz) 1.25 2.5 5.0 10.0 15.0 20.0 Subcarrier bandwidth (kHz) 15 Physical resource block (PRB) bandwidth (kHz) 180 Number of available PRBs 6 12 25 50 75 100
  56. 56. Transmission BW 1.25 MHz 2.5 MHz 5 MHz 10 MHz 15 MHz 20 MHz Sub-frame duration 0.5 ms Sub-carrier spacing 15 kHz Sampling frequency 192 MHz (1/2x3.84 3.84 MHz 7.68 MHz 15.36 MHz 23.04 MHz 30.72 MHz Parameters for DL generic frame structure 56 Sampling frequency (1/2x3.84 MHz) 3.84 MHz 7.68 MHz (2x3.84 MHz) 15.36 MHz (4x3.84 MHz) 23.04 MHz (6x3.84 MHz) 30.72 MHz (8x3.84 MHz) FFT size 128 256 512 1024 1536 2048 OFDM sym per slot (short/long CP) 7/6 CP length (usec/ samples) Short (4.69/9) x 6, (5.21/10) x 1 (4.69/18) x 6, (5.21/20) x 1 (4.69/36) x 6, (5.21/40) x 1 (4.69/72) x 6, (5.21/80) x 1 (4.69/108) x 6, (5.21/120) x 1 (4.69/144) x 6, (5.21/160) x 1 Long (16.67/32) (16.67/64) (16.67/128) (16.67/256) (16.67/384) (16.67/512)
  57. 57. LTE – Spectrum Flexibility • LTE physical layer supports any bandwidth from 1.4 MHz to 20 MHz in steps of 180 kHz (resource block). • Current LTE specification supports a subset of 6 different system bandwidths. • All UEs must support the maximum bandwidth of 20 MHz.• All UEs must support the maximum bandwidth of 20 MHz.
  58. 58. E-UTRA channel bandwidth
  59. 59. Case StudyCase Study LTE Signal Spectrum (20 MHz case) 59 • The LTE standard uses an over-sized LTE. The actual used bandwidth is controlled by the number of used subcarriers. 15 kHz subcarrier spacing is the constant factor! • 18 MHz out of 20 MHz is used for data, 1 MHz on each side is used as guard band. • LTE used spectrum radio = 90% • WiMAX used spectrum radio = 82%
  60. 60. TDD & FDD 60 • Time Division Duplex (TDD) • Frequency Division Duplex (FDD) • Durasi Frame : 2.5 - 20ms
  61. 61. Tf = 307200 x Ts = 10 ms Tslot = 15360 x Ts = 0.5 ms Generic LTE Frame Structure type 1 (FDD) 61 • Untuk struktur generik, frame radio 10 ms dibagi dalam 20 slot yang sama berukuran 0.5 ms. • Suatu sub-frame terdiri dari 2 slot berturut-turut, sehingga satu frame radio berisi 10 sub-frame. • Ts menunjukkan unit waktu dasar yang sesuai dengan 30.72 MHz. • Struktur frame tipe-1 dapat digunakan untuk transmisi FDD dan TDD.
  62. 62. LTE Frame Structure type 1 (FDD) 62 • 2 slots form one subframe = 1 ms • For FDD, in each 10 ms interval, all 10 subframes are available for downlink transmission and uplink transmissions. • For TDD, a subframe is either located to downlink or uplink transmission. The 0th and 5th subframe in a radio frame is always allocated for downlink transmission.
  63. 63. Downlink LTE Frame Structure type 1 (FDD)
  64. 64. Generic LTE Frame Structure type 2 (TDD) 64 • Struktur frame tipe-2 hanya digunakan untuk transmisi TDD. • Slot 0 dan DwPTSdisediakan untuk transmisi DL, sedangkan slot 1 dan UpPTS disediakan untuk transmisi UL.
  65. 65. LTE Frame Structure type 2 (TDD) 65
  66. 66. Mobile WiMAX Frame Structure 66
  67. 67. LTE Frame Structure type 2 (TDD)
  68. 68. DL Peak rates for E-UTRA FDD/TDD frame structure type 1 Downlink Assumptions 64 QAM Signal overhead for reference signals and control channel occupying one OFDM symbol Unit Mbps in 20 MHz b/s/Hz Requirement 100 5.0Requirement 100 5.0 2x2 MIMO 172.8 8.6 4x4 MIMO 326.4 16.3
  69. 69. UL Peak rates for E-UTRA FDD/TDD frame structure type 1 Uplink Assumptions Single TX UE Signal overhead for reference signals and control channel occupying 2RB Unit Mbps in 20 MHz b/s/Hz Requirement 50 2.5Requirement 50 2.5 16QAM 57.6 2.9 64QAM 86.4 4.3
  70. 70. Peak rates for E-UTRA TDD frame structure type 2 Downlink Uplink Assumptions 64 QAM, R=1 Single TX UE, 64 QAM, R=1 Unit Mbps in 20 MHz b/s/Hz Mbps in 20 MHz b/s/Hz in 20 MHz in 20 MHz Requirement 100 5.0 50 2.5 2x2 MIMO in DL 142 7.1 62.7 3.1 4x4 MIMO in DL 270 13.5
  71. 71. 3GPP TR 25.912 Technical Specification Group Radio Access Network; Feasibility study for evolved Universal Terrestrial Radio Access (UTRA) and Universal Terrestrial Radio Access Network (UTRAN) Release Freeze meeting Freeze date :: Rel-7 RP-33 2006-09-22 :: event version available RP-27 0.0.0 2005-03-03 RP-31 0.0.4 2006-03-20 draft 0.1.0 2006-03-20 draft 0.1.1 2006-03-20 post RP-31 0.1.2 2006-03-30 R3-51b 0.1.3 2006-05-02 draft post Shanghai 0.1.4 2006-05-22 draft 0.1.5 2006-07-10 draft 0.1.6 - draft 0.1.7 2006-05-29 RP-32 0.2.0 2006-06-12 RP-32 7.0.0 2006-06-23 RP-33 7.1.0 2006-10-18 RP-36 7.2.0 2007-08-13
  72. 72. 3GPP TR 25.912 Technical Specification Group Radio Access Network; Feasibility study for evolved Universal Terrestrial Radio Access (UTRA) and Universal Terrestrial Radio Access Network (UTRAN) Rel-8 SP-42 2008-12-11 :: . ETSI event version available remarks SP-42 8.0.0 2009-01-02 Upgraded unchanged from Rel-7 RTR/TSGR- 0025912v800 Rel-9 SP-46 2009-12-10 :: Upgraded to Rel-9 with no technical change to enable reference related to ITU-R IMT-Advanced submission (reference in 36.912). . ETSI (reference in 36.912). . event version available remarks RP-45 9.0.0 2009-10-01 Technically identical to v8.0.0 RTR/TSGR- 0025912v900 Rel-10 SP-51 2011-03-23 :: Upgraded from previous Release without technical change . ETSI event version available remarks SP-51 10.0.0 2011-04-06 Automatic upgrade from previous Release version 9.0.0 RTR/TSGR- 0025912va00 Rel-11 SP-57 2012-09-12 :: Upgraded from previous Release without technical change . ETSI event version available remarks SP-57 11.0.0 2012-09-26 Automatic upgrade from previous Release version 10.0.0 -
  73. 73. Session 3: SC-FDMA •Introduction SC-FDMA and UL frame structure•Introduction SC-FDMA and UL frame structure •How to generate SC-FDMA •How does SC-FDMA signal look like •SC-FDMA Signal Generation •SC-FDMA PAPR •SC-FDMA Parameterization
  74. 74. LTE Uplink Transmission Scheme: SC-FDMA • Pemilihan OFDMA dianggap optimum untuk memenuhi persyaratan LTE pada arah downlink, tetapi OFDMA memiliki properti yang kurang menguntungkan pada arah Uplink. • Hal tsb terutama disebabkan oleh lemahnya peak-to-average power ratio (PAPR) dari sinyal OFDMA, yang mengakibatkan buruknya coverage uplink. • Oleh karena itu, skema transmisi Uplink LTE untuk mode FDD maupun TDD didasarkan pada SC-FDMA, yang mempunyai properti PAPR lebih baik. 74 didasarkan pada SC-FDMA, yang mempunyai properti PAPR lebih baik. • Pemrosesan sinyal SC-FDMA memiliki beberapa kesamaan dengan pemrosesan sinyal OFDMA, sehingga parameter-parameter DL dan UL dapat diharmonisasi. • Untuk membangkitkan sinyal SC-FDMA, E-UTRA telah memilih DFT- spread-OFDM (DFT-s-OFDM).
  75. 75. OFDMA and SC-FDMA • The symbol mapping in OFDM happens in the frequency domain. • In SC-FDMA, the symbol mapping is done in the time domain. 75 domain. • Appropriate subscriber mapping in the frequency domain allows to control the PAPR. • SC-FDMA enable frequency domain equalizer approaches like OFDMA
  76. 76. Comparison of how OFDMA and SC-FDMA transmit a sequence of QPSK data symbols 76
  77. 77. Creating the time- domain waveform of an SC-FDMA symbol Comparison of how OFDMA and SC-FDMA transmit a sequence of QPSK data symbols 77 Baseband and shifted frequency domain representations of an SC-FDMA symbol
  78. 78. How to generate SC-FDMA? • DFT “pre-coding” is performed on modulated data symbols to transform them into frequency domain, • Sub-carrier mapping allows flexible allocation of signal to available sub-carriers, • IFFT and cyclic prefix (CP) insertion as in OFDM, • Each subcarrier carries a portion of superposed DFT spread data symbols, therefore SC-FDMA is also referred to as DFT-spread- OFDM (DFT-s-OFDM).
  79. 79. How does a SC-FDMA signal look like? • Similar to OFDM signal, but… – …in OFDMA, each sub-carrier only carries information related to one specific symbol, – …in SC-FDMA, each sub-carrier contains information of ALL transmitted symbols.transmitted symbols.
  80. 80. SC-FDMA signal generation Localized vs. distributed FDMA
  81. 81. SC-FDMA – Peak-to-average Power Ratio (PAPR) Comparison of CCDF of PAPR for IFDMA, LFDMA, and OFDMA with M = 256 system subcarriers, N=64 subcarriers per users, and a = 0.5 roll factor; (a) QPSK; (b) 16-QAM Source: H.G. Myung, J.Lim, D.J. Goodman “SC-FDMA for Uplink Wireless Transmission”, IEEE VEHICULAR TECHNOLOGY MAGAZINE, SEPTEMBER 2006
  82. 82. SC-FDMA parameterization (FDD and TDD) LTE FDD •Same as in downlink 82 TD-LTE •Usage of UL depends on the selected UL-DL configuration (1 to 8), each configuration offers a different number of subframes (1ms) for uplink transmission, •Parameterization for those subframes, means number of SC-FDMA symbols same as for FDD and depending on CP,
  83. 83. Improved UL Performance SC-FDMA compared to ordinary OFDM 83 Single-carrier transmission in uplink enables low PAPR that gives more 4 dB better link budget and reduced power consumption compared to OFDM
  84. 84. LTE Uplink SC-FDMA Physical Layer Parameters 84
  85. 85. Physical Channel Processing • Scrambling: Scramble binary information • Modulation Mapper: Maps groups of 2, 4, or 6 bits onto QPSK, 16QAM, 64QAM symbol constellation points 85 • Transform Precoder: Slices the input data vector into a set of symbol vectors and perform DFT transformation. • Resource Element Mapper: Maps the complex constellation points into the allocated virtual resource blocks and performs translation into physical resource blocks. • SC-FDMA Signal Generation: Performs the IFFT processing to generate final time domain for transmission.
  86. 86. Single Carrier Constellation Mapping S/P Convert M-Point DFT Subcarrier Mapping N-Point IDFT Cyclic Prefix & Pulse Shaping RFE Bit Stream Channel Symbol Block SC-FDMA and OFDMA Signal Chain Have a High Degree of Functional Commonality 86 Const. De-map S/P Convert M-Point IDFT Freq Domain Equalizer N-Point DFT Cyclic Prefix Removal RFE Bit Stream Symbol Block SC Detector Functions Common to OFDMA and SC-FDMA SC-FDMA Only
  87. 87. Session 4: Network and Protocol •Network architecture•Network architecture •Protocol Stack – User plane •Protocol Stack – Control plane •Mapping between logical and transport channel •LTE UE Categories
  88. 88. LTE Network Architecture GGSN UMTS 3G: UTRAN SGSN MMEMME SS--GW / PGW / P--GWGW MMEMME SS--GW / PGW / P--GWGW EPC UMTS : Universal Mobile Telecommunications System UTRAN : Universal Terrestrial Radio Access Network GGSN : Gateway GPRS Support Node GPRS: General Packet Radio Service SGSN : Serving GPRS Support Node RNC: Radio Network Controller NB: Node B RNC RNC NB NB NB NB eNB eNB eNB eNB E-UTRAN EPC ; Evolved Packet Core MME : Mobility Management Entity S-GC : Serving Gateway P-GW : PDN Gateway PDN : Packet Data Network eNB : E-UTRAN Node B / Evolved Node B E-UTRAN ; Evolved-UTRAN
  89. 89. Simplified LTE network elements and interfaces 3GPP TS 36.300 : Overall Architecture MMEMME SS--GW / PGW / P--GWGW MMEMME SS--GW / PGW / P--GWGW EPC EPC: Evolved Packet Core Radio Side: LTE – Long Term Evolution • Improvements in spectral efficiency, user throughput, latency. • Simplification of the radio network • Efficient support of packet services • Main Components: • MME = Manages mobility, UE identity, and security parameters. • S-GW = Node that terminates the interface towards E-UTRAN. S1 eNB eNB eNB eNB E-UTRAN towards E-UTRAN. • P-GW = Node that terminates the interface towards PDN E-UTRAN : Evolved-UTRAN Network Side : SAE – System Architecture Evolution • Improvement in latency, capacity, throughput • Simplification of the core network • Optimization for IP traffic services • Simplified support and handover to non-3GPP access technologies • Main Components: • eNB = All radio interface-related functions X2
  90. 90. S-GW P-GW MME Operator’s IP Services LTE-Uu SGi RxGx S5 / S8 S6a S1-MME S1-U EPS Network Elements E-UTRAN EPC • UE, E-UTRAN and EPC together represent the Internet Protocol (IP) Connectivity Layer. • This part of the system is also called the Evolved Packet System (EPS). • The main function of this layer is to provide IP based connectivity, and it is highly optimized for that purpose only. • All services will be offered on top of IP, and circuit switched nodes and interfaces seen in earlier 3GPP architectures are not present in E-UTRAN and EPC at all. • IP technologies are also dominant in the transport, where everything is designed to be operated on top of IP transport. eNB UE S-GW P-GW IP Services (e.g. IMS, PSS, etc,) LTE-Uu SGiS5 / S8S1-U
  91. 91. System architecture for E-UTRAN only network
  92. 92. Services • The IP Multimedia Sub-System (IMS) is a good example of service machinery that can be used in the Services Connectivity Layer to provide services on top of the IP connectivity provided by theconnectivity provided by the lower layers. • For example, to support the voice service, IMS can provide Voice over IP (VoIP) and interconnectivity to legacy circuit switched networks PSTN and ISDN through Media Gateways it controls.
  93. 93. EPC • Functionally the EPC is equivalent to the packet switched domain of the existing 3GPP networks. • Significant changes in the arrangement of functions and most nodes and the architecture in this part should be considered to be completely new. • SAE GW represents the combination of the two gateways, Serving Gateway (S-GW) and Packet Data Network Gateway (P-GW) defined for the UP handling in EPC. • Implementing them together as the SAE GW represents one possible deployment scenario, butrepresents one possible deployment scenario, but the standards define the interface between them, and all operations have also been specified for when they are separate. • The Basic System Architecture Configuration and its functionality are documented in 3GPP TS 23.401. • We will learn the operation when the S5/S8 interface uses the GTP protocol. However, when the S5/S8 interface uses PMIP, the functionality for these interfaces is slightly different, and the Gxc interface also is needed between the Policy and Charging Resource Function (PCRF) and S-GW. One of the big architectural changes in the core network area is that the EPC does not contain a circuit switched domain, and no direct connectivity to traditional circuit switched networks such as ISDN or PSTN is needed in this layer.
  94. 94. E-UTRAN • The development in E-UTRAN is concentrated on one node, the evolved Node B (eNodeB). • All radio functionality is collapsed there, i.e. the eNodeB is the termination point for all radio related protocols.related protocols. • As a network, E-UTRAN is simply a mesh of eNodeBs connected to neighbouring eNodeBs with the X2 interface.
  95. 95. User Equipment • UE is the device that the end user uses for communication. • Typically it is a hand held device such as a smart phone or a data card such as those used currently in 2G and 3G, or it could be embedded, e.g. to a laptop. • UE also contains the Universal Subscriber Identity Module (USIM) that is a separate module from the rest of the UE, which is oftenmodule from the rest of the UE, which is often called the Terminal Equipment (TE). • USIM is an application placed into a removable smart card called the Universal Integrated Circuit Card (UICC). • USIM is used to identify and authenticate the user and to derive security keys for protecting the radio interface transmission. • Maybe most importantly, the UE provides the user interface to the end user so that applications such as a VoIP client can be used to set up a voice call. Functionally the UE is a platform for communication applications, which signal with the network for setting up, maintaining and removing the communication links the end user needs. This includes mobility management functions such as handovers and reporting the terminals location, and in these the UE performs as instructed by the network.
  96. 96. User Equipment Capabilities • Support Spectrum flexibility – Flexible bandwidth – New and existing bands 20 MHz1.4 MHz AnalogAnalog 1G DigitalDigital 2G PacketsPackets 3G True Broadband True Broadband4G
  97. 97. Downlink physical layer parameter values set by the field UE-Category UE Category Maximum number of DL-SCH transport block bits received within a TTI (Note) Maximum number of bits of a DL-SCH transport block received within a TTI Total number of soft channel bits Maximum number of supported layers for spatial multiplexing in DL Category 1 10296 10296 250368 1 Category 2 51024 51024 1237248 2 Category 3 102048 75376 1237248 2 Category 4 150752 75376 1827072 2 Category 5 299552 149776 3667200 4 Category 6 301504 149776 (4 layers) 3654144 2 or 4Category 6 301504 149776 (4 layers) 75376 (2 layers) 3654144 2 or 4 Category 7 301504 149776 (4 layers) 75376 (2 layers) 3654144 2 or 4 Category 8 2998560 299856 35982720 8 NOTE: In carrier aggregation operation, the DL-SCH processing capability can be shared by the UE with that of MCH received from a serving cell. If the total eNB scheduling for DL-SCH and an MCH in one serving cell at a given TTI is larger than the defined processing capability, the prioritization between DL-SCH and MCH is left up to UE implementation. TTI = Transmission Time Interval 3GPP TS 36.306 V11.1.0 (2012-09) 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) radio access capabilities MIMO = Multiple Input Multiple Output UL-SCH = Uplink Shared Channel DL-SCH = Downlink Shared Channel UE = User Equipment TTI = Transmission Time Interval
  98. 98. Transmission Time Interval • Transmission Time Interval: Transmission Time Interval is defined as the inter-arrival time of Transport Block Sets, i.e. the time it shall take to transmit a Transport Block Set. • Transport Block Set: Transport Block Set is defined as a set of Transport Blocks that is exchanged between L1 and MAC at the same time instance using the same transport channel. Anthe same time instance using the same transport channel. An equivalent term for Transport Block Set is “MAC PDU Set”. • Transport Block: Transport Block is defined as the basic data unit exchanged between L1 and MAC. An equivalent term for Transport Block is “MAC PDU”. 3GPP TR 21.905 V11.2.0 (2012-09) 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Vocabulary for 3GPP Specifications (Release 11)
  99. 99. Uplink physical layer parameter values set by the field UE-Category UE Category Maximum number of UL- SCH transport block bits transmitted within a TTI Maximum number of bits of an UL-SCH transport block transmitted within a TTI Support for 64QAM in UL Category 1 5160 5160 No Category 2 25456 25456 No Category 3 51024 51024 NoCategory 3 51024 51024 No Category 4 51024 51024 No Category 5 75376 75376 Yes Category 6 51024 51024 No Category 7 102048 51024 No Category 8 1497760 149776 Yes 3GPP TS 36.306 V11.1.0 (2012-09) 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) radio access capabilities
  100. 100. eNB Functional split between E-UTRAN and Evolved Packet Core E-UTRAN aGW • Paging origination • LTE_IDLE mode management • Ciphering of the user plane • Header Compression (ROHC) eNodeB • All Radio-related issues • Decentralized mobility management • MAC and RRM • Simplified RRC aGW Internet S1 The E-UTRAN consists of eNBs, providing: • The E-UTRA U-plane (RLC/MAC/PHY) and • The C-plane (RRC) protocol terminations towards the UE. • The eNBs interface to the aGW via the S1 RRM : Radio Resource Management RRC: Radio Resource Control MAC : Medium Access Control ROHC: RObust Header Compression RLC: Radio Link Control PHY: Physical Layer
  101. 101. eNB Protocol Inter Cell RRM RB Cont. Connection Mobility Cont. Radio Admission Cont. eNB Measurement Configuration & Provision Dynamic Resource Allocation (Scheduler) MME NAS Security Idle State Mobility Handling EPS Bearer Cont. SAE GW EPC E-UTRAN RRM : Radio Resource Management RB : Radio Bearer RRC: Radio Resource Control PDCP : Packet Data Convergence Protocol RLC : Radio Link Control MAC : Medium Access Control PHY : Physical Layer Allocation (Scheduler) RRC PDCP RLC MAC PHY UE IP Address Allocation Packet Filtering P-GW Mobile Anchoring S-GW SAE GW NAS : Non Access Stratum EPS : Evolved Packet System UE : User Equipment IP : Internet Protocol Internet S1
  102. 102. eNB LTE Control Plane NAS RRC PDCP RLC MAC PHY S1 UE RRC PDCP RLC MAC PHY NAS aGW Non Access Stratum (NAS) is a functional layer in UMTS protocol stack between Core Network and User Equipment (UE). The layer supports signaling and traffic between two elements. eNB LTE User Plane IP PDCP RLC MAC PHY S1 UE PDCP RLC MAC PHY IP aGW Packet Data Convergence Protocol (PDCP) is a one of the layers of Radio Traffic Stack in UMTS and perform as IP header compression and decompression, transfer of user data and maintenance of sequence numbers for Radio Bearers which are configured for lossless Serving Radio Networks Subsystems (SRNS) relocation.
  103. 103. LTE Protocol Stacks (UE and eNB) RRC: Radio Resource Control PDCP : Packet Data Convergence Protocol RLC : Radio Link Control MAC : Medium Access Control PHY : Physical Layer RRC PDCP Control-Plane L3 User-Plane L2 Radio Bearers RLC MAC PHY: Physical Channels Physical Signals L1 Transport Channels Logical Channels
  104. 104. Control plane protocol stack in EPS The topmost layer in the CP is the Non-Access Stratum (NAS), which consists of two separate protocols that are carried on direct signaling transport between the UE and the MME. The content of the NAS layer protocols is not visible to the eNodeB, and the eNodeB is not involved in these transactions by any other means, besides transporting the messages, and providing some additional transport layer indications along with the messages in some cases.
  105. 105. NAS layer protocols The NAS layer protocols are: • EPS Mobility Management (EMM): The EMM protocol is responsible for handling the UE mobility within the system. It includes functions for attaching to and detaching from the network, and performing location updating in between. This is called Tracking Area Updating (TAU), and it happens in idle mode. Note that the handovers in connected mode are handled by the lower layer protocols, but the EMM layer does include functions for re-activating the UE from idle mode. The UE initiated case is called Service Request, while Paging represents the network initiated case. Authentication and protecting the UE identity, i.e. allocating theinitiated case. Authentication and protecting the UE identity, i.e. allocating the temporary identity GUTI to the UE are also part of the EMM layer, as well as the control of NAS layer security functions, encryption and integrity protection. • EPS Session Management (ESM): This protocol may be used to handle the bearer management between the UE and MME, and it is used in addition for E-UTRAN bearer management procedures. Note that the intention is not to use the ESM procedures if the bearer contexts are already available in the network and E- UTRAN procedures can be run immediately. This would be the case, for example, when the UE has already signaled with an operator affiliated. Application Function in the network, and the relevant information has been made available through the PCRF.
  106. 106. User plane protocol stack in EPS The UP includes the layers below the end user IP, i.e. these protocols form the Layer 2 used for carrying the end user IP packets. The protocol structure is very similar to the CP. This highlights the fact that the whole system is designed for generic packet data transport, and both CP signaling and UP data are ultimately packet data. Only the volumes are different.
  107. 107. Summary of interfaces and protocols in Basic System Architecture configuration
  108. 108. Protocol Architecture
  109. 109. LTE MAC Layer Functions
  110. 110. LTE Channel Architecture
  111. 111. Downlink layer 2 structure
  112. 112. Uplink layer 2 structure
  113. 113. LTE Downlink Channels
  114. 114. LTE Downlink Logical Channels 1
  115. 115. LTE Downlink Logical Channels 2
  116. 116. LTE Downlink Transport Channels 1
  117. 117. LTE Downlink Transport Channels 2
  118. 118. LTE Downlink Physical Channels 1
  119. 119. LTE Downlink Physical Channels 2
  120. 120. LTE Uplink Channels
  121. 121. LTE Uplink Logical Channels
  122. 122. LTE Uplink Transport Channels
  123. 123. LTE Uplink Physical Channels
  124. 124. End of Thank You See you again at