3GPP LTE/5G Networks - Introduction to Cellular Networks - Kyunghan Lee Networked Computing Lab (NXC Lab) Department of Electrical and Computer Engineering Seoul National University https://nxc.snu.ac.kr [email protected] WIRELESS NETWORKING, 430.752B, 2020 SPRING AdaptedSEOUL from NATIONALProf. Sunghyun UNIVERSITYChoi’s slides 5 WirelessRoadmap Networks - Roadmap IMT-Advanced Mobility Standard LTE-A Pro 2015 2010 Rel. 13/14 1995 2000 2005 High LTE-A (Up to 350 km/h) Rel. 10-12 *Rel. 13 (03/2016) LTE 3G 3G Ev. 1G 2G IEEE IEEE 802.20 802.16m W-CDMA MBWA CDMA AMPS HSDPA/HSUPA GSM CDMA2000/Ev-DV/DO Medium IEEE (Vehicular) 802.16e WiBro/M-WiMAX F-WiMAX IEE 802.11ac IEEE VHT Low 802.16 a/d 802.11n (Nomadic) IEEE WLAN 802.11a/b 14.4 kbps 144 kbps 384 kbps ~50 Mbps ~100 Mbps ~1 Gbps Peak Data Rate WIRELESS NETWORKING, 430.752B, 2020 SPRING MWNL SEOUL NATIONAL UNIVERSITY Multimedia & Wireless Networking Lab. Wireless Networks - Roadmap Source: https://semiengineering.com/should-we-even-be-talking-about-6g/ WIRELESS NETWORKING, 430.752B, 2020 SPRING SEOUL NATIONAL UNIVERSITY History □ LTE (Long Term Evolution) § LTE is 3GPP system for the years 2010 to 2020 and beyond § It must keep the support for high mobility users like in GSM/UMTS § LTE(-A) is the latest standard in the mobile network technology tree that previously realized the GSM/EDGE and UMTS/HSPA network technologies □ LTE–Advanced § LTE-A is often used for LTE Release 10 and beyond § Formal name is Advanced E-UTRA (evolved universal terrestrial radio access) § Cost-efficient support for backward and forward compatibility between LTE and LTE-A WIRELESS NETWORKING, 430.752B, 2020 SPRING SEOUL NATIONAL UNIVERSITY Standardization for LTE-A □ 3GPP (Third Generation Partnership Project) § 3GPP was to make a globally applicable third-generation (3G) mobile phone system specification based on evolved Global System for Mobile Communications (GSM) within the scope of the IMT-2000 project § Organizational partners • ETSI (Europe), T1 (USA), TTA (Korea), TTC (Japan), CWTS (China) https://www.qualcomm.com/ news/onq/2017/08/02/ 3GPP Organization Structure 3GPP Organization understanding-3gpp-starting-basics WIRELESS NETWORKING, 430.752B, 2020 SPRING SEOUL NATIONAL UNIVERSITY Motivation □ Need for higher data rates and greater spectral efficiency § New air interface defined by 3GPP LTE □ Need for packet switched optimized system § Evolve UMTS towards packet only system □ Need for high quality of services (QoS) § Use of licensed frequency to guarantee QoS § Reduce round trip delay □ Need for cheaper infrastructure § Simplify architecture § Reduce number of network elements WIRELESS NETWORKING, 430.752B, 2020 SPRING SEOUL NATIONAL UNIVERSITY Terminology □ LTE (Long Term Evolution) § Evolution of 3GPP Radio Access Technology § E-UTRAN (Evolved Universal Terrestrial Radio Access Network) □ SAE (System Architecture Evolution) § Evolution of 3GPP Core network technology (started from 3GPP rel.8) § EPC (Evolved Packet Core) • No more consideration for circuit switching (GSM) or circuit/packet dual (GPRS, UMTS) □ EPS (Evolved Packet System) § Evolution of the complete 3GPP UMTS Radio Access, Packet Core and its integration into legacy 3GPP/non-3GPP networks § E-UTRAN + EPC WIRELESS NETWORKING, 430.752B, 2020 SPRING SEOUL NATIONAL UNIVERSITY Overview of LTE Design Benefits □ New architecture § Flat architecture: one type of node, i.e., eNB § PS core network optimized § No CS core network □ New interfaces design § Simplified protocol stack § Simple, more efficient QoS § IP network layer WIRELESS NETWORKING, 430.752B, 2020 SPRING SEOUL NATIONAL UNIVERSITY Key Features of LTE(-A) □ Bandwidth support § Flexible component carrier from 1.4 MHz to 20 MHz § Maximum 100 MHz by aggregating 5 component carriers □ Multiple access scheme § Downlink: OFDMA § Uplink: Single Carrier FDMA (SC-FDMA) □ Duplex mode § FDD: Frequency division duplexing • Full-duplex and half duplex § TDD: Time division duplexing • Half duplex WIRELESS NETWORKING, 430.752B, 2020 SPRING SEOUL NATIONAL UNIVERSITY Carrier Aggregation 13 Carrier Aggregation 13 □ Carrier Aggregation (CA) Carrier Aggregation § Transmission Bandwidth can be• furtherIntra-band extended CA by means of CA • Intra-band CA § Up to 5 component carriers can be• Contiguous aggregated component for transmission carriers • Contiguous component carriers bandwidth up to 100 MHz • Non-contiguous component carriers • Non-contiguous component carriers § CA systems are deployed to improve• Inter- banddata CArates for users • Inter-band CA § Backwards compatablity is supported• Non -forcontiguous Rel. 8/9 component users carriers • Non-contiguous component carriers □ Intra-band CA § Contiguous component carriers Frequency band A Frequency band B Frequency band A Frequency band B Intra-band § Non-contiguous component carriers Intra-band Frequency band A Frequency band B Frequency band A Frequency band B Inter-band □ Inter-band CA Frequency band A Frequency band B Inter-band § Frequency band A Frequency band B Non-contiguous component carriers MWNL Multimedia & Wireless Networking Lab. MWNL WIRELESS NETWORKING, 430.752B, 2020 SPRING Multimedia & Wireless Networking Lab. SEOUL NATIONAL UNIVERSITY UE Categories 15 UE Categories □ UE categories depending on maximum peak data rate and MIMO • UEcapabilities categories depending support on maximum peak data rate and MIMO capabilities support Note:Note: Total numbernumber of of soft soft channel channel bits bitsfor HARQ for HARQ ≈ 8 (# ≈of 8Independent (# of Independent HARQ process HARQ IDs) process × 3 (# ofIDs) retransmitted× 3 (# of retransmitteddata) data) × maximum number of bits of DL-SCH TB received× maximum within numbera TTI of bits of DL-SCH TB received within a TTI WIRELESS NETWORKING, 430.752B, 2020 SPRING SEOUL NATIONAL UNIVERSITY Source: http://blog.3g4g.co.uk/2015/05/new-lte-ue-categories-11-12-13-and-14.html MWNL Multimedia & Wireless Networking Lab. Initial Cell Search and Selection □ Primary Synchronization Signal (PSS) & Secondary Synchronization Signal (SSS) § Frequency and time synchronization § Physical layer cell ID determination □ Master Information Block (MIB) § Transmission bandwidth and system frame number □ System Information Block (SIB) 16 § InitialCell access Cell configuration Search and Selection eNB PSS SSS MIB SIB Random Access UE • Primary SynchronizationWIRELESS Signal NETWORKING, (PSS) 430.752B, & Secondary 2020 SPRING Synchronization Signal (SSS) SEOUL NATIONAL UNIVERSITY • Frequency and time synchronization • Physical layer cell ID determination • Master Information Block (MIB) • Transmission Bandwidth and system frame number • System Information Block (SIB) • Cell access configuration MWNL Multimedia & Wireless Networking Lab. Downlink Data Transmission □ Channel State Information (CSI) § Channel Quality Indicator (CQI), etc. □ Scheduling § Based on CQI □ HARQ ACK (or NACK) and CSI 17 Downlink Data Transmission Data arrival eNB Scheduling … DL control info. ACK or NACK DL data CSI CSI UE • Channel State Information (CSI) WIRELESS NETWORKING, 430.752B, 2020 SPRING • Channel Quality IndicatorSEOUL (CQI), NATIONAL etc. UNIVERSITY • Scheduling • Based on CQI • HARQ ACK (or NACK) and CSI *HARQ: Hybrid Automatic Retransmission reQuest MWNL Multimedia & Wireless Networking Lab. Uplink Data Transmission □ Scheduling Request (SR) □ Uplink grant □ Buffer Status Report (BSR) □ Uplink resource scheduling □ Uplink data transmission § If more uplink data arrives à piggybacking BSR 18 Uplink Data Transmission eNB SR UL grant BSR Scheduling UL data (BSR) UE Data arrival (Data arrival) • Scheduling Request (SR) WIRELESS NETWORKING, 430.752B, 2020 SPRING • Uplink grant SEOUL NATIONAL UNIVERSITY • Buffer Status Report (BSR) • Uplink resource scheduling • Uplink data transmission • If more uplink data arrives ‰ piggybacking BSR MWNL Multimedia & Wireless Networking Lab. 22 LTE Network Architecture LTE Network Architecture UMTSUMTS (3G) (3G) LTELTE (4G)(4G) WIRELESS NETWORKING, 430.752B, 2020 SPRING MWNL SEOUL NATIONAL UNIVERSITY Multimedia & Wireless Networking Lab. Overall Architecture □ Basic EPC architecture with E-UTRAN § User plane (data plane) 23 •OverallAII-IP packet Architecture for a UE is encapsulated and tunneled between the P-GW and eNodeB • Protocol support GTP (GPRS Tunneling Protocol) tunnel associated with each EPS bearer § Control• Basic planeEPC architecture with E-UTRAN • Control signals (channel setup, mobility support, security, etc.) between UE and MME • Signals for establishing the radio bearers and configuration EPC (Core Network) E-UTRAN (Access Network) Serving PDN External GW GW Network UE eNodeB MME HSS Control Plane User Plane WIRELESS NETWORKING, 430.752B, 2020 SPRING SEOUL NATIONAL UNIVERSITY MWNL Multimedia & Wireless Networking Lab. Functional LTE Network Elements □ Evolved Node B (eNB) § Supporting LTE radio interface § Performing radio resource management □ Mobility Management Entity (MME) § Managing user equipment mobility, identity and security parameters □ Home Subscriber Server (HSS) § Managing all subscriber information of a network service provider □ Serving Gateway (S-GW) § Routing/forwarding data packets § Mobility anchoring for 3GPP mobility □ Packet Data Network Gateway (PDN-GW) § UE IP address allocation § Mobility anchoring for non-3GPP mobility WIRELESS NETWORKING, 430.752B, 2020 SPRING SEOUL NATIONAL UNIVERSITY LTE to 5G (NSA and SA) (KT 5G NSA (KT and SA) netmanias.com Source: • AMF: Access and Mobility Management Function, SMF: Session Management Function