| 39715 | The Telecommunications Industry Association (TIA) |
Telecommunications Industry Association (TIA) Revises Terminal Equipment Labeling Standard
Update Eliminates Ringer Equivalence Number ‘ZZ,’ Ringer Type ‘Z’ Arlington, Va. – The Telecommunications Industry Association (TIA), the leader in advocacy, standards development, business development and intelligence for the information and communications technology (ICT) industry, has revised its standard TIA-168-A, Telecommunications – Telephone Terminal Equipment – Labeling Requirements. The TIA-168-B, Telecommunications Telephone Terminal Equipment Labeling Requirements, specifies approved standards for labeling telephone terminal equipment. The revised version of TIA-168-A eliminates the ringer type “Z” and reduces the pool of valid equipment REN (ringer equivalent number) codes. REN is an indication of the ringer load a telephone places on the line during an on-hook state. A REN of 1 is the equivalent loading of the generic style 500 telephone. The sum of all telephones on a single line could not exceed a REN of 5, to insure proper signaling during a ringing state. The “Z” ringer type was an REN number beyond the typical load limit that was conditionally allowed by the local telephone operating company at their discretion. This Z ringer type was typically used on telephones with an older style message waiting lamp indicator. Grandfathering provisions were made for existing equipment using those codes. The equipment-labeling standard was revised to reflect TIA-968-A-4,Technical Requirements for Connection of Terminal Equipment to the Telephone Network, which eliminated use of the conditional “Z” ringer type for new telephone terminal equipment after August 2007. TIA-168-B was formulated under the cognizance of the TIA TR-41, User Premises Telecommunications Requirements Committee Subcommittee TR-41.9, Technical and Administrative Regulatory Considerations. To obtain copies of the document, contact IHS International at +1.800.854.7179 (United States and Canada); +1.303.397.7796 (international) or visit global.ihs.com.
