IEEE 1914.3-2018 pdf free download – IEEE Standard for Radio over Ethernet Encapsulations and Mappings.
5.3.3 RoE mappers/RoE de-mappers An RoE mapper is a function/process that converts other transport framing formats to an RoE framing format, and an RoE de-mapper performs the opposite function. This specification describes different flavors of RoE mappers. Structure-aware and native RoE mappers separate control data and sample data into different channels. Control data is fed to a block known as the “control process” in this specification (see 8.3.4). On the RoE de-mapper direction, the RoE control packets received by the control process are fed to RoE de- mappers with the .flowID set to ALL_ONES flowID and the .deMapperID set to appropriate values by the control process.
The chief function of an RoE mapper is to select the appropriate input data from the input data stream (e.g., a CPRI port) and then packetize it. The RoE mapper also generates or selects control information. Individual subclauses in this specification describe the operation of RoE mappers and RoE de-mappers. The RoE mapper is responsible for generating the ordering information. The functionality of the ordering information is described in
5.5.5. Structure-agnostic RoE mappers do not have control packets because the entire data stream (including control information) is encapsulated as a single LC D data channel.
5.3.4 CPRI ports CPRI (or CPRI-like) ports are physical connections. In structure-aware and structure-agnostic mappingmodes, an RoE node has CPRI (or CPRI-like) ports. CPRI (or CPRI-like) ports are assumed to be bidirectional.
5.3.5 subType mapping object The subType mapping object is a table used to maintain and assign mapped subTypes (as specified in Table 2) from the RoE subtype space to particular organizationally unique identifier (OUI) or company identifier (CID) entities and their specified subType/payload structures.
RoE nodes process mapped subTypes, the corresponding payload structure, and optional reserved bits in seqNum as specified by the OUI or CID entity. OUI or CID values are obtained through IEEE registration. An implementation can pre-populate the mapping table with implementation-specific default values. Unused/un-mapped OUI/CID subTypes are indicated by setting the .mapSubtype bits 15 to 0 toALL_ONES.
5.4 RoE traffic types
RoE frames are encapsulated in Ethernet frames as shown in Figure 7. For this standard, the SA, DA, and frame check sequence (FCS) are implicit to all RoE packets. The RoE EtherType value is specified in 4.2. This standard focuses on the fields contained in the RoE header and RoE payload fields.
5.5 RoE common frame format
5.5.1 General
This subclause documents the octets of the frame (i.e., the RoE header) that are common to all RoE flow data and control packets. Figure 8 illustrates the frame format and its fields. The common RoE frame format has the following header fields:
a) subType (subtype) field: 8 bits
b) flowID (flow identifier) field: 8 bits
c) length (length) field: 16 bits [2 most significant bits (MSBs) are reserved for future use by this standard]
d) orderInfo (timeStamp/seqNum) field: 32 bits
The RoE common frame header is placed into the transport protocol payload field, which in this standard’s context is the Ethernet frame payload field.
5.5.2 Subtype (subType) field
The 8-bit subType field is used to define the RoE subtype and the type of flow carried by the RoE packets. This standard reserves the subtypes listed in Table 3.IEEE 1914.3 pdf download.