ECPRI测试原理和测试方法.pptx

eCPRI Primer,Be Ready to Participate in the Conversation,Rev. A October 2017,Base station functions are co-located with the radio tower at the base of the antenna or basement of a tall building. Drawbacks of co-location: RF and Baseband Processing are co-located at the base of the tower. Needs to be physically located very close to the antenna because they are driven over very lossy electrical cables. High power dissipation require costly special enclosures with climate control and power redundancy Makes it difficult to install and find a location that can host the enclosure and/or increase lease price due to additional space needed,Traditional Macro-cell,Information of VeEX Inc.,2,Electrical Cable,Cell Site Cabinet,Mobile Backhaul,RF,BB,Separation of RF and Baseband processing. Simplified function makes it more compact, easier to install and therefore increases the number of possible sites Fiber Link replaces COA Less power required at the cell site Less processing and power requirements at the cell site Smaller footprint, easier to find sites Fiber allows great distance between the RRH and BBU location. All BBUs located at the CO.,CPRI/OBSAI Fronthaul Network,Information of VeEX Inc.,3,Fiber,Mobile Backhaul,RF,BB,Mobile Fronthaul: CPRI/OBSAI,Mobile Fronthaul Testing,Confidential & Proprietary Information of VeEX Inc.,4,Evolution of Mobile Fronthaul: eCPRI,Why eCPRI? CPRI requires high data rate This is not scalable for 5G traffic eCPRI is designed to meet the needs for 5G Improves bandwidth efficiency Increases capacity eCPRI uses packet-based transport network IP or Ethernet,eCPRI uses packet based transport network IP or Ethernet: using a switched or routed mobile fronthaul network makes it more flexible eCPRI uses existing standards for Transport Network Layer (Ethernet/IP) Synchronization (SyncE/PTP) C&M (SNMP, Ethernet OAM) eCPRI introduces a functional split for baseband processing between BBU and RRH. The Functional Split defined in the protocol adapts to the application. It is a tradeoff between latency requirements and bandwidth reduction,Mobile Fronthaul Testing,Confidential & Proprietary Information of VeEX Inc.,5,How does eCPRI achieve this?,Front Haul Evolution,Information of VeEX Inc.,6,Mobile Backhaul,BBU Pool,CPRI/OBSAI Fronthaul,RF,RF,RF,BB,BB,BB,BB,Mobile Backhaul,BBU Pool,RF,BB,BB,BB,BB,BB,RF,BB,RF,BB,eCPRI Fronthaul,eRE = eCPRI Radio Equipment (Remote Radio Head) eREC = eCPRI Radio Equipment Controler (Baseband Unit) 3 data flows between RE and REC: Synchronization traffic (1588 PTP) Control and Management Traffic User Plane traffic (I/Q samples),Mobile Fronthaul Testing,Confidential & Proprietary Information of VeEX Inc.,7,eCPRI Elements,eRE,eREC,BBU,Synchronization,C&M Data,User Plane data (I/Q),RRH,Mobile Fronthaul Transport Network,eCPRI Protocol Stack,Mobile Fronthaul Testing,Confidential & Proprietary Information of VeEX Inc.,8,Ethernet PHY,Optional IP/UDP,eCPRI Protocol,I/Q User Data,eCPRI Physical Layer,Mobile Fronthaul Testing,Confidential & Proprietary Information of VeEX Inc.,9,The following Ethernet interfaces are allowed in the standard:,How is eCPRI data Framed?,Mobile Fronthaul Testing,Confidential & Proprietary Information of VeEX Inc.,10,Option 1: eCPRI over Ethernet,Option 2: eCPRI over IP/UDP,Destination MAC,Source MAC,Type = AEFE,Ethernet Payload,CRC,eCPRI Header,eCPRI Payload = I/Q data or control data,Optional VLAN,New eCPRI Ethertype,MAC Header,IP Header,UDP Header,Ethernet Payload,CRC,eCPRI Header,eCPRI Payload = I/Q data or control data,Optional VLAN,Standard defines eCPRI messages for One-Way Delay Measurement between eRE/eREC eCPRI One-Way Delay measurement requires that both ends are time synchronized to the same source eCPRI One-Way Delay uses Delay request/ Follow-up and Delay Response mechanism,Mobile Fronthaul Testing,Confidential & Proprietary Information of VeEX Inc.,11,One-Way Delay Measurement,Mobile Fronthaul Testing,Confidential & Proprietary Information of VeEX Inc.,12,eCPRI Synchronization,eCPRI node are frequency and phase synchronized eRE/eREC synchronization path can be different from data path eRE/eREC synchronization from PTP/SyncE eRE synchronization requirement more strict than eREC, because eRE generates frequency for air transmission PTP Synchronization per ITU-T Telecom Profile,Mobile Fronthaul Testing,Confidential & Proprietary Information of VeEX Inc.,13,eCPRI Synchronization Testing Requirements,Source: Requirements for the eCPRI Transport Network,Defined in the eCPRI Transport Network Requirements shall meet the following the following criteria:,Mobile Fronthaul Testing,Confidential & Proprietary Information of VeEX Inc.,14,Transport Network Testing Requirements,RoE Standard: IEEE 1914.3 CPRI encapsulated into Ethernet In Process of being standardized with planned 2017 release RoE takes existing CPRI frames and encapsulates into Ethernet frames or alternatively takes frequency domain I/Q data and encapsulates into Ethernet RoE is compatible with existing CPRI whereas eCPRI is a completely new protocol not backward compatible with CPRI Possibly RoE and eCPRI will cohabit RoE used for exi