| SDH STM-1/4 ring | Access to SDH STM-16/64 backbone |
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| Ring are most typical optical applications. | Ring are most typical optical applications. |
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E1, E3, FE, GE, STM-1 access point-to-point |
Card & section protection |
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| Access point to point are most typical optical applications. | ESSI buss for crossconnect stacking and/or card protection. |
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Radio protected optical SDH |
STM-4 rings interconnection |
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| Ideal solution for radio optical applications. | ESSI buss for crossconnect stacking and/or card protection. |
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SDH STM-4 access to the STM-1 radio relay |
Microwave radio STM-1 ring |
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