eCPRI Specification V2 - Common Public Radio Interface

1 eCPRI Specification (2019-05-10) Interface Specification Common Public Radio Interface : eCPRI Interface Specification The eCPRI Specification has been developed by Ericsson AB, Huawei Technologies Co. Ltd, NEC Corporation and Nokia (the Parties ) and may be updated from time to time. Further information about eCPRI , and the latest Specification , may be found at BY USING THE eCPRI Specification , YOU ACCEPT THE Interface Specification Download Terms and Conditions FOUND AT IN ORDER TO AVOID ANY DOUBT, BY DOWNLOADING AND/OR USING THE eCPRI Specification NO EXPRESS OR IMPLIED LICENSE AND/OR ANY OTHER RIGHTS WHATSOEVER ARE GRANTED FROM ANYBODY. 2019 Ericsson AB, Huawei Technologies Co. Ltd, NEC Corporation and Nokia.

2 CPRI eCPRI Specification (2019-05-10) 2 Table of Contents 1 1. Introduction .. 4 2 2. System Description .. 6 3 Definitions/Nomenclature .. 6 4 System Architecture .. 8 5 Functional Description .. 9 6 Functional Decomposition .. 10 7 3. Interface Specification .. 11 8 Protocol Overview .. 11 9 Physical Layer .. 13 10 User Plane .. 13 11 User Plane over Ethernet .. 13 12 User Plane over IP .. 14 13 eCPRI Message Format .. 14 14 eCPRI Transmission Byte Order .. 15 15 Common Header .. 15 16 eCPRI Payload .. 16 17 Mapping Examples .. 16 18 Message Types .. 17 19 Message Type #0: IQ Data .. 17 20 Message Type #1: Bit Sequence .. 19 21 Message Type #2: Real-Time Control Data .. 21 22 Message Type #3: Generic Data Transfer.

3 22 23 Message Type #4: Remote Memory Access .. 24 24 Message Type #5: One-Way Delay Measurement .. 28 25 Message Type #6: Remote Reset .. 34 26 Message Type #7: Event Indication .. 36 27 Message Type #8: IWF Start-Up .. 41 28 Message Type #9: IWF Operation .. 43 29 Message Type #10: IWF Mapping .. 51 30 Message Type #11: IWF Delay Control .. 56 31 Message Type #12 - #63: Reserved .. 57 32 Message Type #64 - #255: Vendor Specific .. 57 33 C&M Plane .. 57 34 Synchronization Plane .. 58 35 QoS .. 58 36 VLAN Tagging for Ethernet-switched fronthaul networks .. 58 37 QoS for IP-routed fronthaul networks .. 58 38 4. Forward and Backward Compatibility .. 59 39 Fixing eCPRI Protocol Revision Position .. 59 40 Reserved Bits and Value Ranges within eCPRI .

4 59 41 eCPRI Specification release version .. 59 42 Specification release version mapping to eCPRI protocol revision .. 59 43 5. Compliance .. 61 44 6. Annex A - Supplementary Specification Details (Informative) .. 62 45 Functional Decomposition .. 62 46 eCPRI Functional Decomposition .. 62 47 Bit Rate Calculations / Estimations .. 64 48 Bit Rate Calculation 64 49 Synchronization and Timing .. 65 50 CPRI eCPRI Specification (2019-05-10) 3 Synchronization of eRE .. 65 1 Synchronization of 65 2 Synchronization of IWFs .. 65 3 Link Delay Management .. 65 4 Reference Points for Delay Measurement .. 66 5 Delay Management example .. 70 6 Network Connection Maintenance .. 72 7 Networking .. 73 8 Difference between eCPRI and CPRI.

5 73 9 eCPRI /CPRI networking with eCPRI /CPRI IWF type 0 .. 74 10 eCPRI /CPRI networking with eCPRI /CPRI IWF type 1 and type 2 .. 75 11 Priority considerations .. 76 12 Message Ordering Considerations .. 76 13 Security .. 77 14 eCPRI Network Security Protocol .. 77 15 eCPRI Network Security Specification .. 77 16 User plane .. 77 17 C&M plane .. 77 18 Synchronization 77 19 7. Annex B eCPRI /CPRI Interworking with IWF type 0 (Informative) .. 78 20 Concept .. 80 21 Bridging of User Plane .. 81 22 Bridging/Routing of C&M Plane .. 82 23 Bridging of Synchronization Plane .. 83 24 Bridging of L1 inband protocol .. 83 25 Start-up Sequence .. 84 26 8. Annex C eCPRI /CPRI Interworking with IWF type 1 and type 2 .. 85 27 Concept.

6 85 28 Definition of IWF type 1 and IWF type 2 CPRI ports .. 85 29 Bridging of User Plane .. 86 30 Bridging/Routing of CPRI Control Words .. 86 31 Bridging of Synchronization Plane .. 86 32 Bridging/handling of CPRI sub-channels 0 and 2 .. 87 33 Start-up Sequence .. 87 34 eCPRI /CPRI IWF Start-up sequence overview .. 87 35 Start-up Delay Management .. 88 36 IWF CPRI port start-up sequence .. 90 37 General .. 90 38 Layer 1 Start-up Timer .. 90 39 State Description .. 91 40 Transition Description .. 95 41 Synchronization .. 97 42 Delay Management .. 97 43 Handling of eCPRI Remote Reset and CPRI Reset .. 100 44 Link and Fault Management .. 100 45 IWF CPRI transmitter fault recovery/actions for CPRI detected 46 faults .. 102 47 IWF CPRI transmitter fault recovery/actions for Ethernet detected 48 faults.

7 102 49 9. List of Abbreviations .. 104 50 10. References .. 107 51 11. History .. 108 52 53 CPRI eCPRI Specification (2019-05-10) 4 1. Introduction 1 The Common Public Radio Interface (CPRI) is an industry cooperation aimed at defining publicly available 2 specifications for the key internal Interface of Radio base stations, such as eCPRI connecting the eCPRI 3 Radio Equipment Control (eREC) and the eCPRI Radio Equipment (eRE) via a so-called fronthaul transport 4 network. The parties cooperating to define the Specification are Ericsson AB, Huawei Technologies Co. Ltd, 5 NEC Corporation and Nokia. 6 7 Motivation for eCPRI : 8 Compared to CPRI [1], eCPRI makes it possible to decrease the data rate demands between eREC and 9 eRE via a flexible functional decomposition while limiting the complexity of the eRE.

8 10 11 Scope of Specification : 12 The necessary items for transport, connectivity and control are included in the Specification . This includes 13 User Plane data, Control and Management Plane transport mechanisms, and means for synchronization. 14 The eCPRI Specification supports 5G and enables increased efficiency in order to meet the needs foreseen 15 for 5G Mobile Networks. In contrast to CPRI, the eCPRI Specification supports more flexibility in the 16 positioning of the functional split inside the Physical Layer of the cellular base station. 17 The scope of the eCPRI Specification is to enable efficient and flexible Radio data transmission via a packet 18 based fronthaul transport network like IP or Ethernet. eCPRI defines a protocol layer which provides various 19 - mainly User Plane data specific - services to the upper layers of the protocol stack.

9 20 The Specification has the following scope (see Figure 1, Figure 1A and Figure 1B): 21 1. The internal Radio base station Interface establishing a connection between eCPRI Radio Equipment 22 Control (eREC) and eCPRI Radio Equipment (eRE) via a packet based transport network is 23 specified. 24 2. Three different information flows ( eCPRI User Plane data, C&M Plane data, and Synchronization 25 Plane data) are transported over the Interface . 26 3. The Specification defines a new eCPRI Layer above the Transport Network Layer. Existing standards 27 are used for the transport network layer, C&M and Synchronization. 28 29 eCPRI Radio Equipment Control (eREC) eCPRI specificUser PlaneSyncC&MeCPRI Radio Equipment (eRE)Transport Network Layer StandardProtocolsSAPUSAPSSAPCMeCPRI specificUser PlaneSyncC&MTransport Network Layer StandardProtocolsSAPUSAPSSAPCMT ransport Network 30 Figure 1: System and Interface Definition 31 The eCPRI Interface can also be used between two eRECs or between two eREs as well as with 32 Interworking Function(s) (IWF) located between the eCPRI transport network and one/several CPRI node(s).

10 33 In Figure 1A the Interworking Function is located between the eCPRI transport network and one/several 34 CPRI RE node(s). The SAPs shall be terminated at both eCPRI and CPRI ends and bridged to each other 35 via vendor specific functionality. For this configuration IWF type 0 is used. 36 CPRI eCPRI Specification (2019-05-10) 5 In Figure 1B the Interworking Functions are located between the respective CPRI nodes and the transport 1 network. The Interworking Functions bridge the CPRI link over the Fronthaul Transport Network. For this 2 configuration IWF type 1 and type 2 are used. 3 4 CPRI Radio Equipment Control (eREC)UserPlaneSyncC&MeCPRI specificSAPUSAPSSAPCMUserPlaneSyncC&MCPR I Radio Equipment (RE)Layer 2 SAPIQSAPSSAPCMS tandardProtocolsTransport Network LayerUser PlaneSyncC&MeCPRI/CPRI Interworking Function type 0 Layer 2 SAPIQSAPSSAPCMeCPRI specificUser PlaneSyncC&MStandardProtocolsSAPUSAPSSAP CMIWFL ayer 1 Layer 1 Transport Network Layer TransportNetwork5 6 Figure 1A: System and Interface Definition with eCPRI /CPRI IWF type 0 7 8 CPRI Radio Equipment Control (REC)User PlaneSyncC&MLayer 1 Layer 2 SAPIQSAPSSAPCMT ransport NetworkUser PlaneSyncC&MCPRI Radio Equipment (RE)Layer 1 Layer 2 SAPIQSAPSSAPCMIWF type 2 IWFtype 19 10 Figure 1B.