Programming instructions

Downloading and Using Files
Data Transfer Troubleshooting
Chapter 4 193
In this example, a modified PN9, 511-bit data pattern is to be applied as the data source for a
114-bit data field in a GSM Normal timeslot.
Set up a spreadsheet containing:
A = number of repetitions of the original data pattern
B = user file length = number of repetitions × original data pattern length
C = Number of characters = user file length ÷ 8 (8 bits-per-character)
D = number of frames = user file length ÷ timeslot data field size (114)
E = total required PRAM = number of frames × number of bits-per-frame (1250 for GSM)
The first row where both columns C and D are integers (the shaded row at the bottom of the
table) is the minimum number of repetitions required to transmit the user file without
discontinuity. In this example, in order to correctly generate the modified PN9 and download
it to a user file, the user file must contain 456 repetitions of the 511-bit pattern. 233,016 total
bits will be downloaded to the signal generator, for a total of 29,127 characters.
AB C D E
Number
of reps
Data
Pattern
Length ×
Repetitions
Number of
Characters
(B ÷ 8)
Number of frames needed to
end on a timeslot boundary
(B ÷ timeslot data field size)
Total PRAM
required
(D × number of
bits-per-frame)
1 511 63.88 4.48 5,603.07
2 1,022 127.75 8.96 11,206.14
3 1,533 191.63 13.45 16,809.21
4 2,044 255.50 17.93 22,412.28
5 2,555 319.38 22.41 28,015.35
6 3,066 383.25 26.89 33,618.42
7 3,577 447.13 31.38 39,221.49
8 4,088 511 35.86 44,824.56
9 4,599 574.88 40.34 50,427.63
... ... ... ... ...
455 232,505 29,063.13 2,039.52 2,549,396.92
456 233.016 29,127 2,044 2,555,000