We were recently asked how technically Sirius and XM might merge their services. We can only speculate.Sirius and XM indicate that each will have its own transmission for years to come. How will they achieve cost savings and continue to operate two satellite constellations? One way would be if they didn’t have to.
The Sirius satellites should operate for at least another 7 or 8 years. In a few years, they will have to think about committing to contracts to replace them. They already have a contract to build a geo-stationary satellite. If they didn’t have to replace any satellites, this could be where they could save in the order one billion dollars or more. They could likely cancel the contract for the geo-stationary satellite as soon as the merger is approved for a penalty.
However, the only way they could do this is if they could use XM’s satellite to transmit the signal for both XM and Sirius. They wouldn’t have to do this until it came time to replace Sirius’ satellites; however, there could be cost savings by doing this earlier than later. It is unlikely that Sirius’ satellites would be of any use to any other entity. They could simply decommission them.
Although we can’t provide a link at present, it was said that Parsons indicated that XM’s satellites could broadcast over the entire satellite radio band. ITU filings seem to indicate that this is true. As we understand it, it takes 4 transmitters per satellite for XM to broadcast its signal, two feeds to each of the two antennae. However, to add the Sirius signal, XM would need only two spare transmitters per satellite capable of being tuned to the Sirius frequency, one for each antenna. In addition, each satellite would also have to have sufficient power to support the additional carriers.
From the technical specifications, the XM uplink is 50 MHz, plenty enough to upload both signals. The satellite can receive LHCP or RHCP, so, if necessary, two separate signals can be uplinked.
XM stated that they would pump 3,600 Watt into each antenna for the downlink, for a total of 7,200 Watt. The payload power is rated at 13,500 Watt, end of life, so they have nearly twice the power they need. Although we can’t confirm it just now, it has been said that the Sirius antennae have a higher gain, so less power would be required. Therefore, it seems that the XM satellites would have enough power to accomplish this.
The Transmitter Redundancy is stated as 4 x (11 for 8); therefore, if we are interpreting this correctly, they have the spare transmitters to add the Sirius signals.
Once they are transmitting on the XM satellites, the same repeater locations could also be used for Sirius. There could be some equipment changes to add the Sirius signal, but there is a good chance that this could be accomplished with relative ease.
The only problem is that the Sirius receiver antennae are optimized for a higher look angle. Reception would not be optimal, but it should be okay. After all, Sirius is planning on putting up a geo-stationary satellite.
Savings: one satellite constellation, station keeping, repeater operation, third party repeater feeds for the Sirius repeaters, and all the various facilities required to uplink the Sirius signal. It should easily be over a billion dollars in savings.
As a temporary solution, the “best of” content would be broadcast to both Sirius and XM receivers. From the merger on, or shortly thereafter, all radios sold or installed would receive only the XM signal. It doesn’t really matter, since they would be identical. Couple this will the hierarchical modulation techniques and they are able to add channel capacity for expanded content for the new receivers. The old receivers would continue to receive the basic signal. The additional content would be so advantageous that many subscribers would buy the new radios. Between the replacement radios and churn and the normal failures over time, most of the old radios on the retail side would be out of service in five years. They could drag the remaining subscribers kicking and screaming to the new service by issuing them new radios. This would be true to a lesser extent for the OEM receivers. At some point, they would have to say, “No mas”, and offer them a voucher to have the receiver replaced. This would finally free up the Sirius bandwidth. The next question is, "What would they do with the extra bandwidth?" Video? On the other hand, if the FCC were to say that they had to give up a license, this is a way they could accomplish it.All this is all pure speculation on our part. We are not rocket scientist nor are we satellite engineers. Any rocket scientist out there that could comment?
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