Paradise P300 specifications Determining Buffer Size, Bs = .002 + 172800 x Ms x Lc + Rc Seconds

These require careful consideration based on the exact situation. If you have questions relating to this subject, and are willing to at least draw a diagram of the system you are implementing then you are welcome to contact us by fax for advice for your exact application.

8.2.3Determining Buffer Size

Use the following calculation to determine the buffer size required for any application:

If	Lc is the local clock accuracy (e.g. ±1 x 10	-9),
and	Rc is the remote clock accuracy (e.g. ±1 x	10 -11)
and	Ms is the Minimum slip period in days (e.g. 40 days)

then the required Plesiochronous Buffer size (middle to end) in seconds is:

Bs = Ms x 24 x 60 x 60 x (Lc + Rc).

Simplifying, allowing a factor of two (end to end buffer, not middle to end) and allowing 2mS for the Doppler shift gives:

Bs = .002 + 172800 x Ms x (Lc + Rc) Seconds.

So using the example figures above gives 0.00898 seconds, so 9ms is required to absorb the plesiochronous effects. To this you must add any Doppler requirement (ie 2ms for each satellite hop).

P300H P300 Series Modem Installation and Operating Handbook Page 142