OMS 3250

Product DescriptionOMS3250• FEC decoder in the receiving Terminal equipment that performs the error correction whileextracting the redundancy to regenerate the data that was encoded by the FEC encoder.Implementation of the In Band FEC (IB FEC) function uses a Hamming code without modifyingthe bit rate of the STM-64 line.Both a proprietary IB FEC and IB FEC as defined in ITU-T G.707 are supported by OMS3250.Implementation of the Out of Band FEC (OOB FEC) function uses the OTU-2 frame structure(as detailed in figure 11-1/G.709 and Table7-1/G.709) and is supported by OTM-m.2 (m=0, 1r)units.It is possible to enable/disable the FEC function by a command entered by NMS or LCT.For STM-64 opt. Interfaces, if Single Mode Fibre is used (i.e. G.652), passive dispersioncompensation devices (PDC) can be provided for long distance applications (typically beyond80 Km).In case of fibre break an automatic laser shutdown is provided to avoid danger caused by theemission of laser light. The procedure for automatic laser shutdown and restart is based on ITU-T/G. 958 (Appendix 2) and on ITU-T/G.664.As laser shutdown facility is implemented, as specified in ITU-T G. 958, Section 9.7.If the Optical Amplifiers are equipped, an automatic power shutdown is provided. Theprocedures for automatic power shutdown and restart are based on ITU-T G. 681, Section 10and on ITU-T G.664.3.4.1 SDH Multirate cardThree variants of this card provide a maximum of 16, 8 and 4 ports respectively, where eachport is equipped with hot-pluggable transceivers. Such transceivers are in the form of SFPmodules supporting STM-1, STM-4 and STM-16 with different optical reaches as follows, thusproviding a very high degree of flexibility both in terms of traffic management and fibre linklength. Each port may be equipped at any time, even after the card has been put into service,without any impairment to the ports already configured.• STM-1 S-1.1, L-1.1 or L-1.2• STM-4 S-4.1, L-4.1 or L-4.2• STM-16 I-16, S-16.1, L-16.1 or L-16.2SFP electrical modules for STM-1 are foreseen when commercially available.The SDH Multirate cards can be equipped and programmed to support many differentconfigurations. In their basic form, the cards can be configured to support the following full,single-rate configurations (MULTIPORT functionality) which may also be used to replaceprevious SDH card types:• 4xSTM-16;• 8xSTM-4;• 16xSTM-1Then with the addition of a hardware key to enable the MULTIRATE functionality, mixedconfigurations with STM-1, STM-4 and STM-16 are also supported, with the constraint of notexceeding 1 x STM-64-equivalent bandwidth.Page 22 of 74 Copyright – Refer to Page 2 Issue 1