scope:

This standard provides the signaling requirements associated with analog, voicegrade, switched access lines with the network-implemented coin-operated payphone (NICOP) feature. This standard is intended to be used in conjunction with American National Standard for Telecommunications - Interface Between Carriers and Customer Installations - Analog Voicegrade Switched Access Lines Using Loop-Start and Ground-Start Signaling, T1.401.

The NICOP feature, which is also known as the Central-Office-Implemented Coin-Operated Payphone feature, provides coin control signals to the customer installation (CI). CI equipment that utilizes this signaling is normally coin-operated payphones that have coin handling, coin accounting, card handling, and other special capabilities. Implementations of such capabilities are outside the scope of this standard.

This standard does not address dial pulse signaling. This standard also does not address the interface associated with station-implemented or instrument-implemented coin-operated payphones. In addition, this standard does not address coin first pay phones nor does it address coinless payphones that do not permit coin-operation at all. These payphones are not compatible with analog, switched, access lines equipped with the NICOP coin control signaling described in this standard. Information about the characteristics of switched access lines for station-implemented coin-operated payphones and coinless payphones may be found in Annex A.

Requirements in this standard are specified at the interface between telecommunications carriers and customer premises cabling and equipment. In this standard, the telecommunications carrier network is referred to as the network and customer premises cabling and equipment is referred to as the customer installation. The interface between the network and the CI is referred to as the Network Interface (NI).

The signals that the network presents at the NI are basically of two types: normal telecommunications system voltages and currents, and voltages and currents due to maintenance activities. The normal signals are specified in this standard; the maintenance signals are not. Abnormal voltages and currents that are the result of the environment (e.g., contact with power lines, power line faults, or lightning) are not covered in this standard.

Tariffs, contracts, or regulatory acts in various jurisdictions may contain additional or more stringent requirements than those in this standard.

Purpose

The purpose of this standard is to assist manufacturers, and users of products to be connected to the network, to understand the characteristics of carrier networks when the NICOP feature is provided on analog, voicegrade, switched access lines with loop-start supervisory signaling. The interface requirements in this standard may be useful in minimizing incompatibility problems, although this standard is not intended to be an equipment specification.

Application

This standard assumes the existence of an analog, voicegrade, switched access line with the NICOP feature. Availability of this feature depends on the network equipment serving the NI. The NICOP feature is not available on all loop-start NIs. When the NICOP feature is provided, other loop-start supplemental features (e.g., Calling Number Delivery, Calling Name Delivery, Distinctive Alerting, etc.) may not be available.

By mutual agreement of the carriers involved, this standard may be applicable to certain carrier-to-carrier interfaces. At these interfaces, one carrier would provide the network characteristics described in this standard and the other carrier would provide the CI characteristics. The physical connection in such instances would be in a manner mutually agreed upon by the parties rather than by a registered connector (e.g., RJ11C).

This standard documents the operation of the NICOP feature as implemented by most telephone systems today. It describes the interworking between a central office based coin line circuit and conventional, electromechanical paystation instruments such as the Type A, - B, - C or - D-series from AT&T, Type 120B from GTE, and the Centurion from Northern Electric, etc. These types of conventional paystations are still deployed in large numbers and may continue to be deployed in the future. Payphone service providers installing new telephone systems frequently deploy so-called smart coin operated telephones that connect to regular loop-start access lines defined in T1.401. In the case of smart coin operated telephones the NICOP functions have been relocated from the network to the payphone.

This standard assumes that customer premises equipment (CPE) exists at the CI that can (1) receive NICOP coin control signals and (2) generate coin deposit signals. Such equipment is sometimes called networkimplemented, Central-Office-Implemented, or network-controlled coin-operated payphones.

Because of the wide range of network switching systems, customer loop plant, and network transport systems in North America, conformance with this standard does not guarantee interface compatibility under all possible operating conditions. In addition, the interface described in this standard may not be universally available.