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: nRF and Baseband Processing are co-located at the base of the tower. nNeeds to be physically located very close to the antenna because they are driven over very lossy electrical cables. nHigh power dissipation require costly special enclosures with climate control and power redundancy nMakes 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 RFBB nSeparation of RF and Baseband processing. nSimplified function makes it more compact, easier to install and therefore increases the number of possible sites nFiber Link replaces COA nLess power required at the cell site nLess processing and power requirements at the cell site nSmaller footprint, easier to find sites nFiber allows great distance between the RRH and BBU location. nAll 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 TestingConfidential & Proprietary Information of VeEX Inc.4 Evolution of Mobile Fronthaul: eCPRI nWhy eCPRI? nCPRI requires high data rate nThis is not scalable for 5G traffic neCPRI is designed to meet the needs for 5G nImproves bandwidth efficiency nIncreases capacity neCPRI uses packet-based transport network nIP 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 TestingConfidential & 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 R F BB BB BB BB B B R F B B R F B B eCPRI Fronthaul neRE = eCPRI Radio Equipment (Remote Radio Head) neREC = eCPRI Radio Equipment Controler (Baseband Unit) n3 data flows between RE and REC: nSynchronization traffic (1588 PTP) nControl and Management Traffic nUser Plane traffic (I/Q samples) Mobile Fronthaul TestingConfidential & 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 TestingConfidential & Proprietary Information of VeEX Inc.8 Ethernet PHY Optional IP/UDP eCPRI Protocol I/Q User Data eCPRI Physical Layer Mobile Fronthaul TestingConfidential & Proprietary Information of VeEX Inc.9 The following Ethernet interfaces are allowed in the standard: How is eCPRI data Framed? Mobile Fronthaul TestingConfidential & 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 HeaderIP Header UDP Header Ethernet Payload CRC eCPRI Header eCPRI Payload = I/Q data or control data Optional VLAN nStandard defines eCPRI messages for One-Way Delay Measurement between eRE/eREC neCPRI One-Way Delay measurement requires that both ends are time synchronized to the same source neCPRI One-Way Delay uses Delay request/ Follow-up and Delay Response mechanism Mobile Fronthaul TestingConfidential & Proprietary Information of VeEX Inc.11 One-Way Delay Measurement Mobile Fronthaul TestingConfidential & Proprietary Information of VeEX Inc.12 eCPRI Synchronization neCPRI node are frequency and phase synchronized neRE/eREC synchronization path can be different from data path neRE/eREC synchronization from PTP/SyncE neRE synchronization requirement more strict than eREC, because eRE generates frequency for air transmission nPTP Synchronization per ITU-T Telecom Profile Mobile Fronthaul TestingConfidential & Proprietary Information of VeEX Inc.13 eCPRI Synchronization Testing Requirements Source: Requirements for the eCPRI Transport Network nDefined in the eCPRI Transport Network Requirements shall meet the following the following criteria: Mobile Fronthaul TestingConfidential & Proprietary Information of VeEX Inc.14 Transport Network Testing Requirements nRoE Standard: IEEE 1914.3 CPRI encapsulated into Ethernet nIn Process of being standardized with planned 2017 release nRoE takes existing CPRI frames and encapsulates into Ethernet frames or alternatively takes frequency domain I/Q data and encapsulates into Ethernet nRoE is compatible with existing CPRI whereas eCPRI is a completely new protocol not backward compatible with CPRI nPossibly RoE and eCPRI will cohabit nRoE used for