5G Network Architecture Lecturer: Rebwar Karimi Nov 2019 Agenda • • • • • • Mobile Towers Remote Access Networks (D-RAN,C-RAN-V-RAN) Fronthaul Interfaces TSN Mobile Backhaul MEC 5G Network Architecture Mobile Towers D-RAN 2/27 5G Network Architecture Why We Need C-RAN? 3/27 5G Network Architecture C-RAN 4/27 5G Network Architecture V-RAN 5/27 5G Network Architecture V-RAN 6/27 5G Network Architecture Fronthul Interface (BBU <-> RRH) • CPRI • OBSAI • ORI 7/27 5G Network Architecture CPRI • it has introduced in 2003. • The Parties cooperating to define the CPRI Specification and are now encompassing Ericsson, Huawei, NEC and Nokia. • Its latest version is CPRI version 7.0 and has released in 2015. • It specifies a digitized serial interface between a base station referred to as REC in CPRI terminology and an RRH or RE. • REC (on BBU side) and RE (on RRH side) exchange: • User Data • CPRI Control & Management data • CPRI frame synchronization information • The specification supports both electrical and optical interfaces as well as point-topoint, star, ring, daisy-chain topologies. 8/27 5G Network Architecture CPRI • An antenna-carrier (AxC): IQ data of either Rx or Tx of one carrier at one antenna element. • CPRI transports I/Q data of particular antenna and particular carrier. This "unit" is called an AxC unit or Antenna-Carrier unit. • Example: In LTE system, if I=16 bits and Q=16 bits then one AxC is of length 32 bits. CPRI CPRI (Max Distance Can Support) • This distance is constrained by the timing requirement of Hybrid Automatic Retransmit reQuest (HARQ) protocol used as a retransmission mechanism between UE and eNB in an LTE network. Time-Sensitive Networking (TSN) • IEEE in cooperation with CPRI forum has defining a new fronthaul transport standard (under IEEE 802.1cm project) • The requirements can be divided into three categories: • Class 1: I/Q and Control and Management (C&M) data (The round-trip delay for I/Q is limited to 200 µs and maximum frame error rate is 10-7) • Synchronization • Class 2: eCPRI which has been recently added 12/27 5G Network Architecture Synchronization Requirements in TSN • Class A1: Strictest class with time error budget of 12.5 ns (one way) for applications such as MIMO and transmit diversity. • Class A: Time error budget up to 45 ns for applications including contiguous intracell CA. • Class B: Budgets up to 110 ns for non-contiguous intra-cell CA. • Class C: The least strict class delivers a budget up to 1.5 µs from the primary reference time clock40 to the end application clock recovery output. 13/27 5G Network Architecture CPRI Problem in 5G 14/27 5G Network Architecture Solutions • Function Splitting Options in eCPRI • IEEE 1914.1 (NGFI)? 15/27 5G Network Architecture eCPRI • It uses the ethernet based messaging instead of TDM like in CPRI • It doesn’t mandate any physical layer. • Ethernet PHY and OTN can be valid options 16/27 5G Network Architecture Function Splitting • • • • various functional splits offer options for different use cases option 1: CPRI, extremely bandwidth and latency demanding. high order options: much lower bandwidth and latency requirements (like option 2) Lower order options: provide joint coordination/scheduling for advanced mobility application (for example option 7 or 8) 17/27 5G Network Architecture Function Splitting Radio Layer Functions 19/27 5G Network Architecture IEEE 1914.1 Packet-Based Fronthaul Transport Network • Architecture for the transport of mobile fronthaul traffic • Analyzes different functional splits • Purpose: • enable critical 5G use cases such as mMIMO,CoMP,C-RAN • simplifies network design, lowers costs by leveraging mature Ethernet-based solution • Fronthaul architecture: unified management & control common networking protocol and network elements • improves bandwidth efficiency, network scalability, sync performance and supports cooperative radio modes. 20/27 5G Network Architecture Single and Double Split Network Models • NGFI I: interfacing low layers of base station processing chain • NGFI II: interfacing mid/high layers of base station processing chain 21/27 5G Network Architecture Backhaul 22/27 5G Network Architecture Backhaul MEC • MEC or multi-access edge computing is an emerging 5G technology. • it enables provisioning of cloud-based network resources and services near the users.(like processing, storage, network) • MEC servers can be located at different locations within the radio access network depending on technical and business requirements. • The main functions in the MEC platform include routing, network capability exposure, and management • because of processing the corresponding tasks in the proximity of the users so: • reduce network congestion • improve application performance MEC Architectural Aspects • high-level functional entities in the MEC framework: • host-level • MEC host • MEC platform • applications • virtualization infrastructure • the corresponding MEC host-level management entity • network-level • 3GPP radio access networks • the local networks • the external networks • system-level • MEC hosts • MEC management necessary to run MEC applications within an operator network 25/27 5G Network Architecture MEC Architectural Aspects 26/27 5G Network Architecture MEC General Framework 27/27 5G Network Architecture References • • • • • • • • • • • • • • https://www.netmanias.com/en/?m=view&id=blog&no=10670 https://www.netmanias.com/en/?m=view&id=blog&no=6314 https://www.netmanias.com/en/?m=view&id=oneshot&no=6259 https://www.netmanias.com/en/?m=view&id=blog&no=6276 https://www.netmanias.com/en/?m=view&id=blog&no=6220 https://www.rfwireless-world.com/Terminology/CPRI-Line-Rates-and-Transport-Capacity.html https://www.ericsson.com/en/mobility-report/reports/june-2019/mobile-data-traffic-outlook https://www.statista.com/statistics/271405/global-mobile-data-traffic-forecast/ https://www.youtube.com/watch?v=EBXZHIAmmms&t=409s https://www.youtube.com/watch?v=ne06ssVc3X0 https://www.youtube.com/watch?v=UPucJcDAfSk&t=4s https://www.netmanias.com/en/?m=view&id=blog&no=10388&xtag=5g-c-ran-fronthaul-kt-korea-sdn-nfv-sktelecom&xref=mobile-network-architecture-for-5g-era-new-c-ran-architecture-and-distributed-5g-core https://www.youtube.com/watch?v=oaPRRbiaMyc https://www.netmanias.com/en/?m=view&id=blog&no=10388&xtag=5g-c-ran-fronthaul-kt-korea-sdn-nfv-sktelecom&xref=mobile-network-architecture-for-5g-era-new-c-ran-architecture-and-distributed-5g-cores 5G Network Architecture Thank You ?
