SDH emerged from a set of modifications to the SONET (Synchronous Optical NETwork) standard and was adopted as a standard by CCITT in 1988. It uses fiber optic links to take advantage of the high bandwidth and reliability of the fiber optic medium.
Advantages of SDH systems
- Brings worldwide standardisation through a single international hierarchy
- Operates at capacities able to meet the needs of GSM, data and internet networks
- Enables protected and redundant circuits with a high quality of service
- Provides access from the lowest to the highest rate on a single system
- Has a practical and powerful operation/management system with advanced fault, configuration and performance management, providing flexibility and reliability
SDH system rates
| SDH | SONET | Rate |
|---|---|---|
| STM-1 | OC-3 | 155 Mbps |
| STM-4 | OC-12 | 622 Mbps |
| STM-16 | OC-48 | 2.4 Gbps |
| STM-64 | OC-192 | 10 Gbps |
| STM-256 | OC-768 | 40 Gbps |
SDH products
Raisecom ITN2100
A multiservice SDH that, alongside SDH functions, provides PDH, TDM over IP and SHDSL connectivity. Supports STM-1, STM-4, STM-16 and STM-64.
Raisecom OPCOM3500
A 5U, 15-slot member of the SDH family supporting STM-1 and STM-4. In addition to E1 ports it supports Ethernet and E3. Features GFP, VCG, LCAS, VC-4 and VC-12 with cross-connection support.
Raisecom OPCOM3101
A mini SDH product with fixed 1+1 STM-1 port and 63 × E1 port capacity. Supports 126 × 126 VC-12 non-blocking capacity and ALS (Automatic Laser Shutdown).
Raisecom OPCOM3103
A mini SDH product with fixed 1+1 STM-1 port, 32 × E1 ports and 8 Ethernet ports. One free slot accepts an E3 or Ethernet card.
Raisecom OPCOM3107
A mini SDH product with fixed 1+1 STM-1 port, 8 or 16 × E1 ports and 4 Ethernet ports.
Tejas Networks TJ1400 / TJ1400-7
SDH devices with a robust architecture that maintain redundancy under all conditions, supporting STM-1, STM-4, STM-16 and STM-64. They feature power and control card redundancy, EOW support and alarm outputs, with E1, Ethernet and Gigabit Ethernet downlink ports.
PDH – Multiplexer products
Raisecom RC3000-15
A multiservice multiplexer that performs all functions either as SDH or as PDH as required. It is 5U with 15 slots and can operate with redundant power and control cards. Services at both STM-1 and E1 level run simultaneously. Managed and configured with Nview NNM software.
PortsE1, Ethernet, E&M, FXS, FXO, V.24, RS-232, V.35, RS-485, G.703 Co-directional 64K, Magneto Telephone
Raisecom RC3000E
The extended model of the RC3000 family, offering the same port and service flexibility in a more compact chassis.