Fiber Optic Patch Cords GRADE Standard

The GRADE standard for fiber optic patch cords is mainly used to evaluate the performance indicators of fiber optic patch cords, such as insertion loss (IL), return loss (RL), etc. Different standard organizations and industry specifications grade the quality of fiber optic patch cords, the most common of which are Telcordia GR-326, IEC 61300-3-35, TIA/EIA 568.3-D and ISO/IEC 11801.

1. Fiber Optic Patch Cord GRADE Classification

Fiber optic patch cords are usually classified according to insertion loss (IL) and return loss (RL). The following are common grade standards:

(1) IEC 61753-1 (International Electrotechnical Commission)

IEC standard divides fiber optic connectors into three grades according to insertion loss (IL):

Grade Single-mode (SM) Insertion loss (IL) Multimode (MM) Insertion loss (IL)

B (Advanced) ≤ 0.12 dB ≤ 0.25 dB

C (Standard) ≤ 0.25 dB ≤ 0.50 dB

D (Economy) ≤ 0.50 dB ≤ 0.75 dB

At the same time, there are corresponding standards for return loss (RL):

Grade Single-mode (SM) Return loss (RL) Multimode (MM) Return loss (RL)

B (Advanced) ≥ 50 dB ≥ 30 dB

C (Standard) ≥ 45 dB ≥ 25 dB

D (Economy) ≥ 35 dB ≥ 20 dB

(2) Telcordia GR-326 (North American Standard)

Telcordia GR-326 is a fiber optic connector standard commonly used in the North American market, which specifies strict performance requirements:

Single-mode (SM)

Insertion loss (IL): ≤ 0.4 dB

Return loss (RL): UPC ≥ 50 dB, APC ≥ 60 dB

Multimode (MM)

Insertion loss (IL): ≤ 0.5 dB

Return loss (RL): ≥ 25 dB

In addition, GR-326 also requires that fiber optic patch cords pass mechanical durability (500 plug-in and unplug tests), environmental aging tests, thermal shock tests, etc.

(3) TIA/EIA-568.3-D (North American cabling standard)

TIA/EIA 568.3-D is mainly used for data center and enterprise cabling, and has different grades for the quality of fiber optic patch cords:

Single mode

IL ≤ 0.75 dB (maximum value)

RL ≥ 50 dB (UPC) / RL ≥ 60 dB (APC)

Multimode

IL ≤ 0.75 dB (maximum value)

RL ≥ 20 dB

(4) ISO/IEC 11801 (international standard)

ISO/IEC 11801 is mainly aimed at enterprise and data center cabling, and has the following performance requirements for fiber optic patch cords:

Single mode

IL ≤ 0.3 dB (standard value)

RL ≥ 45 dB (UPC) / RL ≥ 60 dB (APC)

Multimode

IL ≤ 0.5 dB (standard value)

RL ≥ 25 dB

2. How to choose the appropriate GRADE standard

High performance requirements (such as 5G, data centers) → select IEC Class B, GR-326, TIA-568.3-D

General enterprise and ISP networks → select IEC Class C, ISO/IEC 11801

Cost-sensitive projects (ordinary FTTH connections) → select IEC Class D

Different GRADE levels directly affect the stability, insertion loss and return loss of the optical fiber network.