Which of the following is NOT part of the ANSI/TIA-942 rating definition?

The ANSI/TIA-942 standard defines four levels of redundancy and reliability for data centre infrastructure, known as "Rated" levels. These are Rated-1 (Basic Site Infrastructure), Rated-2 (Redundant Capacity Component Site Infrastructure), Rated-3 (Concurrently Maintainable Site Infrastructure), and Rated-4 (Fault Tolerant Site Infrastructure). The standard does not define a "Rated-5" or a "Hyper-Resilient" category. Therefore, this option is not part of the official TIA-942 rating system.

A. Rated-1 (Basic) is the foundational level defined in the ANSI/TIA-942 standard, representing a single path for power and cooling.
B. Rated-2 (Redundant Capacity) is the second level in the ANSI/TIA-942 standard, adding redundant components to the infrastructure.
C. Rated-3 (Concurrent Maintainable) is the third level in the ANSI/TIA-942 standard, allowing for maintenance without shutting down critical operations.

1. Telecommunications Industry Association. (2017). ANSI/TIA-942-B: Telecommunications Infrastructure Standard for Data Centers. (Section 5.2, "Rating Levels").

2. Uptime Institute. (While a separate system, its Tier levels are often compared, and academic reviews confirm TIA-942 has only four levels). Data Center Site Infrastructure Tier Standard: Topology. (This document helps contextualize the 4-level system common in the industry, which TIA-942 follows with its "Rated" terminology).