IEEE Std 802.1CM:2018 pdf download.IEEE Standard for Local and metropolitan area networks-Time Sensitive Networking for Fronthaul.
This standard defines profiles that select features, options, configurations, defaults, protocols and procedures of bridges, stations, and LANs that arc necessary to build networks that arc capable of transporting fronthaul streams, which are time-sensitive.
NOTE—Stream and flow are used as synonyms in this document,
1.2 Purpose
The purpose of this standard is to specify defaults and profiles that enable the transport of time-sensitive fronthaul streams in Ethernet bridged networks.
1.3 Introduction
Fronthaul provides connectivity between functional blocks of a cellular base station (BS). The fronthaul flows between these functional blocks have stringent quality of service requirements. The successful support of fronthaul flows in a bridged network requires the selection of specific features and options that are specified in a number of different standards, some developed by IEEE Project 8O2, and others (in particular, those that relate to functionality in OSI layer 3 and above; ISO/IEC 7498:1994 [B II]) developed by other standards organizations.
This standard selects features and options that support OSI layers 1 and 2 in bridges and end stations from the following specifications:
-— Virtual Local Area Network (VLAN) Bridge specification in IEEE Std 802. lQ.3 MAC service specifications in IEEE Std 802.lAC.
— MAC/PHY technology specifications in IEEE Std 8O2.3.
— Interspersing express traffic specification in IEEE Std 8O2.3.
- Frame preemption specification in IEEE Std 802.lQ.
Time synchronization and Precision Time Protocol (PTP) specifications in IEEE Std 1588.
— Telecom profile specification in ITU-T G.8275.1, which is based on IEEE Std 1588.
— Synchronous Ethernet specification in ITU-T (18261, G.8262, and G.8264.
To specify and explain the selection of features and options, this standard:
a) Describes fronthaul requirements (Clause 6), specifying two classes of requirements (6.2, 6.3) that depend on the BS functional decomposition, and specifying synchronization requirements (6.4) that apply to both classes.
b) Describes how the operation of bridges and bridged networks affects the quality of service provided by the fronthaul bridged network (Clause 7), providing details to assist in the calculation of latency (7.1, 7.2, 7.3), the selection of network synchronization methods (7.4), and the potential impact of the use of flow control (7.5) and Energy Efficient Ethernet (EEE, 7.6).
c) Specifies two bridge profiles (Clause 8) that support the construction of bridged networks meeting fronthaul requirements. Profile A (8.1) is applicable to bridges that do not support frame preemption (7.3), while Profile B (8.2) involves frame preemption to accommodate larger non-fronthaul flows and frame sizes while preserving fronthaul traffic guarantees.
d) Discusses the applicability (Clause 9) of the synchronization methods described in 7.4 to the time synchronization categories defined in 6.4.1.
e) Defines fronthaul profile conformance requirements (Clause 5) for bridges meeting either Profile A or Profile B requirements, for end stations and for synchronization.
f) Provides a Profile Confbrmance Statement (PCS, Annex A) to support clear detailed statements of equipment confbrrnance to fronthaul profile requirements.IEEE Std 802.1CM pdf download.