28-08-2014, 03:07 PM
STM stands for Synchronous Transport Module.This is the information structure used to support information payload and over head information field organised in a block frame structure which repeats every 125 microseconds.The bit rate of STM-1 is 155.520Mbps. Frame Format The standardized SDH transmission frames, called Synchronous Transport Modules of Nth hierarchical level (STM-N). A frame with a bit rate of 155.52 Mbit/s is defined in ITU-T Recommendation G.707. This frame is called the synchronous transport module (STM). Since the frame is the first level of the synchronous digital hierarchy, it is known as STM-1.
DDF(Digital Distribution Frame) DDF (at transmitter side) receive PCMs from exchange or station which are to be transmitted to another station or exchange. DDF have different modules which connects PCM to STM-1 System. PCM connected to DDF from station through copper cable and from DDF to STM-1 through PCM cable. • Transmitter It is basically STM-1 system which helps to transmit PCMs through optical fibre cable.STM-1 plays an important role in transmission system. STM-1 also helps in cross connect the PCMs. This block contains MUX card and OLT cards. • E/O Converter It is simply OLT card which converts electrical signal to optical signal • FDF(Fibre Distribution frame) This frame (at transmitter end) distribute fibre to different station. FDF connect to system through patch card. • FDF(Fibre Distribution frame) This frame (at receiver end) collect fibrefom different station. FDF connect to system through pigtails cable. • O/E Converter This block converts optical signal to electrical signal. • Receiver This block will collect all PCMs received at OLT card. It will connect all the PCM to MUX card. Here they are connected to different station through DDF. E1 INPUT" and "E1 OUTPUT" ports 21 x 2 Mbit/s traffic ports compliant with the ITU-T G.703 Recommendation (§ 6.3 for input port, § tab.6 for output port) Bit rate 2,048 Mbit/s ± 50 ppm, Code HDB3, Impedance 75 Ω or120 Ω balanced, according to the model of motherboard Connector SUB D HD female 44 pins supporting L907 cable (21 ports). This interface uses two connectors : E1 INPUT connector for inputs (named RX) and E1 OUTPUT connector for outputs (named TX)E1 OUTPUT and E1 INPUT G.703 75 Ω or 120 Ω 2 Mbit/s traffic ports 120Ω input is used for transmission and output is for reception.It is also known as U-link connector.This port is used to connect the exchange side and system side. 4E/FE: Each 4E/FE provides connection for Traffic Ethernet interface either in 10Mbit//s or 100Mbit/s in full or half duplex mode.
DDF(Digital Distribution Frame) DDF (at transmitter side) receive PCMs from exchange or station which are to be transmitted to another station or exchange. DDF have different modules which connects PCM to STM-1 System. PCM connected to DDF from station through copper cable and from DDF to STM-1 through PCM cable. • Transmitter It is basically STM-1 system which helps to transmit PCMs through optical fibre cable.STM-1 plays an important role in transmission system. STM-1 also helps in cross connect the PCMs. This block contains MUX card and OLT cards. • E/O Converter It is simply OLT card which converts electrical signal to optical signal • FDF(Fibre Distribution frame) This frame (at transmitter end) distribute fibre to different station. FDF connect to system through patch card. • FDF(Fibre Distribution frame) This frame (at receiver end) collect fibrefom different station. FDF connect to system through pigtails cable. • O/E Converter This block converts optical signal to electrical signal. • Receiver This block will collect all PCMs received at OLT card. It will connect all the PCM to MUX card. Here they are connected to different station through DDF. E1 INPUT" and "E1 OUTPUT" ports 21 x 2 Mbit/s traffic ports compliant with the ITU-T G.703 Recommendation (§ 6.3 for input port, § tab.6 for output port) Bit rate 2,048 Mbit/s ± 50 ppm, Code HDB3, Impedance 75 Ω or120 Ω balanced, according to the model of motherboard Connector SUB D HD female 44 pins supporting L907 cable (21 ports). This interface uses two connectors : E1 INPUT connector for inputs (named RX) and E1 OUTPUT connector for outputs (named TX)E1 OUTPUT and E1 INPUT G.703 75 Ω or 120 Ω 2 Mbit/s traffic ports 120Ω input is used for transmission and output is for reception.It is also known as U-link connector.This port is used to connect the exchange side and system side. 4E/FE: Each 4E/FE provides connection for Traffic Ethernet interface either in 10Mbit//s or 100Mbit/s in full or half duplex mode.