IEEE Std 802.3cm-2020 pdf free download – IEEE Standard for Ethernet Amendment 7: Physical Layer and Management Parameters for 400 Gb/s over Multimode Fiber.
138. Physical Medium Dependent (PMD) sublayer and medium, type 50GBASE-SR, 100GBASE-SR2, 200GBASE-SR4.400GBASE-SR8
Clause 138 was added to IEEE Std 8023-2018 by IEEE Sid 80.3cd-2018 and molifed by IEEE Std 802.3c1n-2019.
138.1 Overview Change the first paragrph of 138.1 and Table 138 3 as fllous:
This clause specifies the 50GBASE-SR, 100GBASE-SR2, end -200GBASE-SR4_ and 400GBASE-SR8 PMDs together with the multimode fiber medium. The optical signals generated by these three PMD types are modulated using a 4-level pulse amplitude modulation (PAM4) format. The PMD sublayers provide point-to-point 50, 100, and 200. and 400 Gigabit Ethemet links over onc, two, or four. or cight pairs of multimode fiber, with a reach of up to at least 100 m.
Change the third, fourth, and fth paragraphs of 138.1 as fllows
Figure 138- 1 shows the relationship of the PMDs and MDIs (shown shaded) with other sublayers to the ISO/IEC Open System Interconnection (OSI) reference model. 50 Gigabit Ethernet is introduced in Clause131 and the purpose of each PHY sublayer is summarized in 131.2. 100 Gigabit Ethemet is introduced in Clause 80 and the purpose of each PHY sublayer is summarized in 80 2.200 Gigabit Ethernet and 400 Gigabit Ethemet arcis introduced in Clause 116 and the purpose of each PHY sublayer is summarized in 116.2. 5GBASE-SR, 100GBASE-SR2, and 20GBASE-SR4. and 400GBASE-SR8 PHYs with the optional Enengy- Efficient Ethernet (EEE) faust wake capabilty may enter the Low Power Idle (LPI) mode to conserve energy during periods of low link utilization (see Clause 78)- The deep sleep mode of EEE is not supported Furher relewant information may be found in Clause 1 (erminology and conventions, references, definitions . and breviations) and Annex A (bibliogaphy, rferenced as [BI]， [B2]， etc.).
The 50GBASE-SR, 100GBASE-SR2 and 200GBASE-SR4。and 400GBASE-SR8 sublayers provide point-to-point 50, 100, aed 200. and 400 Gigabit Ethemet links over one, two, of -four, or eight pairs of multimodle fiber, u to at least 100 m.
138.1.1 Bit error ratio Change the second paragraph of
138.1.1 as folows: For the 200GBASE-SR4 and 40GBASE-SR8 PMDs, the bit eror ratio (BER) when processed by the PMA (Clause 120) shall be less than 2.4 x 10 4 provided that the error statistics are sufficiently random that this results in a frame loss ratio (see 1.4.275) of less than 1.7x 10-12 for 64-octet frames with minimum interpacket gap when additionally processed by the PCS (Clause 119). For a complete Physical Layer, the frume loss ratio may be degraded to 6.2x 10-11 for 64-octet fames with minimum intepacket gap due to additional errors from the electrical interfaces. If the eror statistics are not sufficiently random to meet this requirement, then the BER shall be less than that required to give a frame loss ratio ofless than 1.7 x 10-12 for 64-octet frames with minimum interpucket gap.
138.2 Physical Medium Dependent (PMD) service interface
Change 138.2 as follows:
This subclause specifies the services provided by the 50GBASE-SR, 100GBASE-SR2, and 200GBASE- SR4, and 400GBASE-SR8 PMDs. The service interfaces for these PMDs are described in an abstract manner and do not imply any particular implementation. The PMD service interface supports the exchange of encoded data between the PMA entity that resides just above the PMD, and the PMD entity.
The PMD translates the encoded data to and from signals suitable for the specified medium.IEEE Std 802.3cm pdf download.