power equivalent bandwidth

Eutelsat used to publish a good guide but it seems to have disappeared, so my explanation:

Power Equivalent Bandwidth (PEB) means the amount of total power used by the carriers and is quantified as the bandwidth equivalent. If you rent a full transponder then the Power Equivalent Bandwidth is quantified as the transponder bandwidth (e.g. 72 MHz).  The actual power in this case will be the saturated power.

If you are renting a fractional lease, say 5 MHz bandwidth, the power you will be allowed will be the saturated power less multicarrier back-off multiplied by the ratio 5/72, in the case of a 72 MHz transponder.

You might use your fractional lease (5 MHz) for one carrier or several smaller ones, totalling the same power.
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Eutelsat said that your share of the power you are allowed from the transponder must be proportional to your paid-for bandwidth versus the bandwidth of the transponder.

The transponder will be backed off for multi-carrier operation, to keep the intermodulation noise level acceptable.

So, for example
If transponder single carrier EIRP=50 dBW (on some contour)
Output back off = 1.5 dB
Total of all carriers in transponder, output EIRP = 48.5 dBW

Transponder bandwidth = 72 MHz.
Your leased bandwidth = 18 MHz

You get 50 - 1.5 + 10 log(18/72) dBW.
= 50 -1.5 -6 dBW

Your downlink carrier EIRP = 42.5 dBW

Best regards, Eric.