BSTU is the ULAF+ family equipment designed for transmission of wide band symmetric traffic over one or two pairs of copper cable using SHDSL.bis technology (ITU-T G.991.2 standard). The sum bit rate in communication line when the signal is transferred over two pairs can reach 11.4 Mbit/s.
The basic variant of the configuration is the availability of two E1 (G.703) modules in one device. One of the digital interfaces (X.21, V.35, V.36) as well as one or two Ethernet 10/100 Base TX interfaces with the 2nd level commutation and VLAN support can be used for data transmission.
Additional advantages:
• Possibility of flexible choice of signal bands ratio in the communication channel
• Considerable improvement of jitter characteristics being an important factor for station equipment synchronization.
Possible types of connection for BSTU equipment.
STU4.bis is the equipment designed for networking with TCP/IP convergence in the network. At the subscriber’s side of the device there are four Ethernet 10/100 Base TX interfaces being the entrance ports of 2nd level exchange built in the device itself. For line interface there are employed four pairs of copper cable with 5.7 Mbit/s bandwidth for each pair operating under SHDSL.bis technology.
Reliability and safety.
The network remains operable even when three of the four existing pairs are disconnected. If all the four pairs are operable the Ethernet bit rate reaches 22.8 Mbit/s (!).
Combined with QSTU modules this type of equipment makes it possible to create a «high-bit-rate last mile» for Ethernets with connection to standard TDM network (for example to SDH/ DWDM networks or to radio relay equipment).
Standard application of STU4.bis equipment is IP-networks connection.
BSRU is SHDSL.bis regenerator, the device that terminates the signal in a copper pair from one direction and regenerates this signal in the other direction. This device is applied for signal multiplication in order to increase “loop” duration. SHDSL.bis technology as well as SHDSL allows installation of up to eight regenerators on one copper cable pair. A considerable difference from the previous types of equipment is the possibility of remote power supply for maximum possible quantity of BSRU regenerators removing communication line length restrictions.
Power supply.
• Direct current — from 48…72V
• Alternating voltage — 220V, it is necessary to apply 220VAC/48VDC external converter. The corresponding mode is to be selected by jumpers setting on mainboard.
In addition, on the boards of the modules of both types it can be installed a remote power supply submodule (DP) making it possible to supply power to the regenerators placed on the line (up to four from each side) or a remote SHDSL.bis-submodule in case of absence of local power supply.
Adjustment. Emergency control and signaling.
Mainly to be performed with the help of software from local computer (LCT) via RS-232 interface or from a remote computer via SNMP protocol through TCP/IP network as well as with the help of microswitches placed on the modules mainboard.
Emergency control is to be performed with the help of software as well as with the help of displaying of the basic type emergencies on the module light-emitting diode panel. In case it is necessary to display the emergencies on the external devices, a corresponding submodule installed on the mainboard of the basic module is applied.
Synchronization.
Is to be performed from four sources: line interface; 2 Mbit/s stationary interface; internal generator; external generator.
