New development.

New development.

New development

The digitalization of communication networks that is currently taking place is primarily due to the use of electronic PBXs as switching nodes. The main transport in this case is the B1 stream (2.048 Mbit/s). When designing complex, branched communication networks, along with low cost and high reliability of the selected equipment, an important place is occupied by multifunctionality, versatility and flexibility.

These are the properties implemented in the universal digital linear path (UDLP) and primary multiplexer (BUS-ZO) — a new development that was completed and launched into production by the subsidiary of the Izhevsk Radio Plant, CS Svyazkompleks, which is engaged in telecommunications. The equipment has passed factory and certified tests and is the basis for the construction and modernization of digital networks at the level of primary flows of 2.048 Mbit/s. It took into account the experience of previously released systems of the ICM15/30 MS type and Radan MS-11 radio relay stations, as well as trends in the construction and development of existing regional communication networks.

The UCLT allows organizing from one to four independent primary digital transmission systems (PDTS) simultaneously. Any of them can be either traditional cable (PCM), or HDSL, radio relay or fiber optic. This simplifies the construction of star or chain communication networks, allows for efficient expansion of the system, and the transition from one transmission medium to another.

The basis of the UCLT is the block of terminations of paths (BOT), its configuration includes the service module KSS and up to four (according to the number of organized paths) sets of linear terminations. Linear sets, depending on the type of path, contain various cells and, as a rule, consist of two boards: linear/station regenerators and remote power supply, or intermediate stations (IS), or radio relay station transceivers. The sets are installed on standardized landing places.

To organize the input/output of linear cables, provide lightning protection and general rack signaling in the UCLT, the UVV block is used.

The primary multiplexer BUS-ZO ensures the matching and compression of analog connecting and subscriber lines of the automatic telephone exchange, digital interfaces into the E1 stream. BUS-ZO is built on the principle of a common bus, to which the cells of channel terminations for various types of interfaces are connected — these are analog terminations for direct subscribers, a joint for the trunk (E&M), three (seven)-wire trunks of the automatic telephone exchange and automatic telephone exchange and various types of digital interfaces (RS-232, V.24 synchronous and asynchronous, counter-directional joint according to the recommendation G.703.1).

The multiplexer design provides a built-in service module that allows for flexible verification and testing of the system. The operation of all BUS-ZO nodes is monitored in the self-diagnostic mode,

When constructing a multi-span line, it is possible to diagnose any remote multiplexer without interrupting traffic and organizing additional channels. Using the service module, you can also view the status of any signaling channel, communicate with your or the opposite side via the E1 flow channel with the imitation of any signaling protocol, check the matching devices, feed a tone frequency signal into the channel and measure its level. At intermediate points, it is possible to organize the allocation of channels (from 1 to 30).

BUS-ZO complies with the requirements of recommendations G.703, G.704, G.706, G.711, G.712, G.713, G.714, G.732 and G.823 ITU-T.

The entire design is implemented in the 19-inch Euroconstruct standard (IEC 297).

The nodes of the UCLT and BUS-ZO systems are based on programmable logic structures (FPGA) from ALTERA, microcontrollers from Microchip and functionally complete microcircuits from Level One and Dallas. The choice when constructing remote power sources was made in favor of DC/DC-converters from the Swiss company TRACO. All this made it possible to ensure high-quality system parameters with its high reliability and low cost.