CIRCUIT DELAY Clause Samples
CIRCUIT DELAY. A System design guideline has been established that recommends that delays from an EBTS cell Site to the MPS be kept to less than 5 ms and the delay from the MPS to the DAP be kept to less than 2.5 ms. This limits the range from an EBTS to an MPS to about 600 (1000 KM) circuit miles if there are no other significant delays in the inter-exchange carrier's network (other than the link propagation delays themselves). Telephone interconnect, short message service and circuit-switched data can tolerate longer delays because of their less critical and less frequent set-up times and audio delay adjustment capability, and thus do not require the above stated dispatch system design criteria. However, extremely long delays (such as satellite hops or terrestrial links that have delays beyond 20 ms. should be avoided as this will add to the telephone audio delay.
CIRCUIT DELAY. The end-to-end circuit delay requirement for MARCS is 7 milliseconds or less (5 ms for the Columbus simulcast sites). AT&T shall take all steps necessary within the existing infrastructure to meet or exceed this circuit delay requirement including but not limited to reverting to the shortest path in normal or recovered operation. This would include redesign of circuits and assigning appropriate staff to meet this measurement. If a major redesign or additional infrastructure is required, then AT&T shall provide details of options available to MARCS including the associated costs to MARCS. MARCS will be responsible for the Circuit Delay measurement and will make those statistics available to AT&T. Due to the critical nature of MARCS communication, MARCS has an availability requirement of 99.98%. AT&T shall meet or exceed this availability requirement by designating MARCS circuits as "Telecommunications Service Priority (TSP)" in order to minimize the mean-time-to-restore (MTTR) for the MARCS System. Due to the critical nature of MARCS communication, MARCS requires a Bit Error Rate (BER) of 10 -9 or less. AT&T shall take all steps necessary to meet or exceed this error rate requirement by assisting the MARCS staff in troubleshooting circuits with BERs in excess of 10 -9. MARCS will be responsible for the BER measurement and will make those statistics available to AT&T. This would include redesign of circuits and assigning appropriate staff to meet this measurement. If a major redesign or additional infrastructure is required, then AT&T shall provide details of options available to MARCS including the associated costs to MARCS. Circuit installations shall provide connectivity from the remote site ▇▇▇▇▇ ▇▇▇▇ to the central equipment ▇▇▇▇▇ ▇▇▇▇ and shall not exceed the postalized rate stipulated in the Synchronous Optical Network Infrastructure Contract, Appendix 3, Tables 3 and 4 unless special construction is required by the Local Exchange Carrier. If special construction is required, then tariff rates shall apply. MARCS will inform AT&T of scheduled installation of other utilities when required and AT&T shall coordinate its installation with those other utility providers to minimize costs to MARCS.