DCPR TRANSITION FROM GOES I/M TO GOES N/P: A UNIQUE OPPORTUNITY FOR POWER REDUCTION DCS MANUFACTURERS MEETING NOVEMBER 9, 2006 Peter Woolner Mitretek Systems

2 CS v.1b to v.2 Transition All changes proposed for Certification Standard v. 2.0 may be mixed with DCPs that comply with v. 1.0b EXCEPT the uplink EIRP limits (at least RF changes) Significant reduction in the required EIRPs for all DCPs is very desirable The transition from GOES I/M series to GOES N/P series provides a unique opportunity that is unlikely to recur

3 SCOPE OF TRANSITION CHANNEL TYPE G-11 & -12 CHANNEL CAPACITY GOES-13 CHANNEL CAPACITY CHANNEL CAPACITY INCREASE 300 bps bps253 CDMA bps (International) 440 Satellite Power (measured PLT) 36.5 dBmi50.5 dBmi14.0 dB NOTE: It is assumed the 100 bps signals have EIRPs between 35 and 50 dBmi and that this will have a negligible effect on the GOES-13 transponder performance

4 Transition Procedure 1.Any v.1.0b DCP can be changed to a v.2 DCP at any time, except for EIRP & FSS 2.They can’t actually operate on the split channels until DAPS and DAMS-NT are upgraded 3.Changing any two adjacent channel (one on each satellite) to new DCPs will give 4 or 5 new channels 4.Changes of any additional adjacent channels (n total) make 2n or 2n+1 new channels available

5 Transition Start: GOES-13 Activated It is assumed the DCPR transponder is loaded to 110% of GOES-11 and -12 capacity for some significant part of each day due to uplink spill-over –96 channels at 300 bps at 47 to 49 dBmi (with some unknown number still at 100 bps plus 4 international channels at 100 bps) –2 channels at 1200 bps and at 50 and 52 dBmi –Uplink equivalent of 113 channels at 48.3 dBmi average It is also assumed the DAPS and DAMS-NT have been upgraded to accommodate CS v.2 changes

6 EIRP Limit Calculation Process Select an EIRP range for 1200 bps signals EIRPs for 300 bps signals is 6 dB less EIRPs for CDMA is 7 dB less Assume bps channels remain in international band in 35 to 50 dBmi range Calculate performance on GOES-13 for: –110% capacity for GOES-11 and GOES-12 –110% capacity for GOES-13 and GOES-O –Capacity throughout transition in 10% steps

7 Requirements for Calculation Results At start of transition, the first DCPRS that changes to CS v.2, even if it is at the specified minimum uplink EIRP, must be able to provide an E B /N 0 of 12.7 dB/Hz to a DRGS w. 15 dB G/T Every new channel to be added will need an old channel to be changed from v.1.0b to v.2 (Remove 1 old channel to add 2 new channels) Include some extra margin for channel flexibility At end of transition, it is desired there be enough margin to allow 20 simultaneous CDMA signals

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11 Recommended EIRP Limits If an EIRP range of 2 dB is acceptable: –1200 bps signals at 45 to 47 dBmi –300 bps signals at 39 to 41 dBmi –CDMA signals at 38 to 40 dBmi If an EIRP range of 4 dB is required: –1200 bps signals at 46 to 50 dBmi –300 bps signals at 40 to 44 dBmi –CDMA signals at 39 to 43 dBmi

12 All DCPs would be able to operate with 1 to 3 dB less EIRP and therefore with less input power Narrow range will permit twice as many CDMA channels as the wide range –Number is not known but the ratio will be about 2 for narrow v. wide EIRP limits The EIRP will have to be adjusted on-site Narrow Range Pro and Con

13 Some form of power adjustment is required to achieve the 2 dB EIRP range Must have a step size of 0.5 dB or less Remote control of the power level would be desirable but is not necessary Access by unauthorized persons must be made reasonably difficult DCP Power Adjustment

14 DCP Power Adjustment (2) Recommend management issue of who can control be separated from technical issue of how control is to be applied Recommend: –Manufacturers should answer the “How?” –NOAA/STIWG should answer the “Who?”

15 Schedule Considerations Current estimate for series transition is: –GOES-12 to GOES-13 ~January 2011 –GOES-11 to GOES-O ~June 2011 –(Based on remaining fuel v. consumption) CS cannot be finalized before January 07 Therefore there will be less than four years in which to prepare Resolution of outstanding items is urgent

16 SUMMARY There are three possibilities: –Prev. proposed levels: 300: 47-49, 1200: –Wide EIRP range: 300: 40-44, 1200: –Narrow EIRP range: 300: 39-41, 1200: The change-over could start as soon as new equipment can be built Partly depends on range of EIRP control that is practical Change is easiest when GOES-13 starts operations, or will need close cooperation