The BTM10 series analyzer is a compact, notebook sized PCM measuring instrument designed for field use in analysis and maintenance of E1 (2.048Mbps) or T1 (1.544Mbps) lines. The -BTM10 performs Frame Analysis, Drop and Insert 64Kbps voice or n* 64Kbps data into any time slot. The BTM10 series analyzer also provides a variety of E1/T1 line statuses, transmission performance testing (BERT) and monitoring. On the E1/T1 line, the BTM10 series product may be used as a generator or receiver. 2.2 Functions • E1/T1 BERT Analysis: E1/T1 frame, code, CRC, and BPV performance analysis and generator. • Alarm and Looping Setting: Manual or automatic alarm and loop setting. • VF Access: Drop and insert 64K voice; Low Frequency Generator (transmit VF Frequency from 60 to 3950 Hz (+3 to -20dBm) • Pulse Shape: E1/T1 pulse shape analysis. • Signal Result: E1/T1 PCM level meter and frequency analysis. • Signaling Setting: ABCD bit setting. • Signaling Display: Display all channels of ABCD bits. • BERT on Data Port: Data port BERT performance analysis. • Examine Analysis: off-line analysis of E1/T1 BERT performance. • External Drop and Insert: Acts as a Fractional E1/T1 converter. • User Programmable Pattern Setting: There is a 32 bits programmable pattern, which can be inserted onto the E1/T1 line and drop for analysis. • Timeslot Setting: Drop and Insert n*64K data onto E1/T1 line. • Timeslot Mapping Data: Analyze any channel data of two frames. E1 Brief History E1 technology has its roots in the original AT&T Tl public telephone networks. The AT&T T1 carrier used PCM (Pulse Code Modulation) and time-division multiplexing over wire pairs with digital repeaters spaced 6000 feet apart. The 24 speech channels we encoded on the 1.544 Mbps bit stream. Seven bits were used for encoding each sample. The system was designed to transmit voice frequencies up to 4 kHz, and therefore required sampling at 8000 samples per second. Each frame was 125 µsec. There are a total of 1 bits in each frame, giving 193 x 8000 = 1.544 Mbps. When T1l facilities were first introduced by AT&T, they were installed mainly in the public telephone network to implement connections between switching offices. The T1 carrier has become ; successful that individual users of telecommunications can now least T1 facilities from a variety of common carriers and are routinely use to implement communication links where high data rates are required. The CCITT has made two recommendations for PCM transmission which can be achieved over most telephone wire pairs, one for the T1 carrier speed of 1.544 Mbps and one for E1 transmission at 2.048 Mbps,. The CCITT recommendation for 1.54* Mbps differs slightly from the North American standard set by ATS It employs a 193 bit frame with 8 bits per channel, and the frame alignment bit is the first bit, not the 193rd as in the AT&T standard. Sixteen frames of 256 bits each are grouped together to form one multi-frame. There are thirty-two 8-bit time slots in each frame, give 30 speech channels of 64 Kbps each, one synchronization channel, and one signaling channel. 64 Kbps x 32 channels = 2.048 Mbps.