The symmetric PSD for data rate of 256, 512, 768, 1536, 2048 and 2304 Kbit/s comply with the PSD masks defined in Annex A of ITU-T G.991.2.
Symbol Rate: (Data rate+8000)/3 symbol/sec
Load Impedance: 135 ohms ±5%.
Physical Connection Type: Standard RJ-45 jack, 135 ohm balanced via 2 wires or 4 wires twisted pair.
Port enabled / disabled configurable.
Network Side Interface.
Bit Rate: 1,544 Kbit / s 32 ppm.
Frame Format: SF (D4), ESF, or ESF+CRC, field selectable.
Line Code: AMI or B8ZS, field selectable.
Impedance: Normal 100 ohms 5% resistive, symmetrical pair.
Power Level: For an all-one transmitted signal, the power in a 3 kHz band centered at 772 kHz is between 12.6 and 17.9 dBm. The power in a 3 KHz band centered at 1544 kHz is at least 29 dB below that at 772 kHz.
Physical Connection Type: Standard RJ-48C/RJ-45 jack (Balance) or BNC (Unbalance).
Signal of input port was defined as above and can be modified by the characteristics of the interconnecting pair. The insertion loss of this pair at a frequency of 1024 kHz is in the range of 0 to 6 dB.
Minimum Return Loss at the Input Port: 12 dB for 51 to 102 kHz, 18 dB for 102 to 2,048 kHz 14 dB for 2,048 to 3,072 kHz
Electrical Characteristics: Comply with ITU-T V.35 interface.
Software configurable for V.35, X.21, RS530, V.36/RS-449.
Data Rate: n x 64 Kbit/ s, where n = 1~36(2 wires) or n=2~ 72(4 wires). The data rate does not include 8 Kbit/s framing overheads.
Provide a 10/100 Base-T half/full duplex auto sensing Ethernet Interface.
At all rates, the transmit symbol clock during data mode from any SHDSL device is accurate to within ±32 ppm of the normal frequency.
When the STU-C receiver loses Transmit data clock, it will fall back and use a free-running local oscillator in the STU-C，the STU-C local oscillator will have the accuracy of ±32 ppm.
The SHDSL transceivers will operate in a master-slave mode with STU-R (Slave) synchronized to the received signal from the STU-C (Master) (i.e. Received symbol clock).
If the STU-R receiver loses timing, it will fall back and use a free-running local oscillator in the STU-R，the STU-R local oscillator will have the accuracy of ±32 ppm.
The SHDSL system is an equipment of frequency transparency. The average traced frequency deviation at the DS1/E1 output port is less than ±1 x 10-11 to the frequency at the DS1/E1 input port under Mode 2 clocking architecture.