This work led to T-carrier and similar digital systems for local use.

The clock rate of an incoming T-carrier is extracted from its bipolar line code.

T-carrier was originally developed for voice applications.

MTP1 normally uses a timeslot in an E-carrier or T-carrier.

When voice signals are digitized for transmission via T-carrier, the data stream always includes ample 1 bits to maintain synchronization.

T-carrier uses robbed-bit signaling: the least-significant bit of the byte is simply forced to a "1" when necessary.

E-carrier is used in place of T-carrier outside the United States, Japan, and South Korea.

It declined in the 1970s due to the adoption of T-carrier, and was largely abandoned late in the century in favor of common-channel signaling.

There are several types of modified AMI codes, used in various T-carrier and E-carrier systems.

Throughout Europe and most of the rest of the world there is a comparable transmission system called E-carrier, which is not directly compatible with T-carrier.

Just as there is the generally known L-carrier and N-carrier systems, T-carrier was the next letter available and T1 is the first level in the hierarchy.

The T-carrier is a member of the series of carrier systems developed by AT&T Bell Laboratories for digital transmission of multiplexed telephone calls.

Common methods of internet access include Dial-up access, landline (over Cable Internet, fiber optic or Telephone cables), T-carrier, Wi-Fi, Satellite Internet and mobile phone.

These early WISPs would employ a high-capacity T-carrier, such as a T1 or DS3 connection, and then broadcast the signal from a high elevation, such as at the top of a water tower.

A common practice in telecommunications, for example in T-carrier, is to insert, in a dedicated time slot within the frame, a noninformation bit or framing bit that is used for synchronization of the incoming data with the receiver.

T-carrier and E-carrier signals are transmitted using a scheme called bipolar encoding, a.k.a. Alternate Mark Inversion (AMI), where a ONE is represented by a pulse, and a ZERO is represented by no pulse.

North American toll-free numbers are controlled by an intelligent network database (SMS/800) in which any toll-free number may be directed to a local or long-distance geographic telephone number, a T-carrier or primary rate interface line under the control of any of various RespOrgs.

The end of multi-frequency (MF) phreaking in the lower 48 United States occurred on June 15, 2006, when the last exchange in the continental United States to use a "phreakable" MF-signalled trunk replaced the aging (yet still well kept) N-carrier with a T-carrier.