Wavetek ANT-20, Operating Manual

Page: 114 / 126

Broadband Analyzer/Generator ANT-20/ANT-20E
S-4 Specifications “ATM Layer”
1.6 Source Models
1.6.1 Constant Bit Rate Model
A cell stream with nominally constant cell spacing is generated.
1.6.2 “On-Off” Model
A burst-type cell stream with on/off character is generated.
Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . peak cell rate and cell jitter”
Peak cell rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 bis 366792 cells/s
1
Peak cell rate units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cells/s, Mbit/s, kbit/s
Peak cell rate resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 cell/s
Maximum possible cell jitter
2
. . . . . . . . . . . . . . . . . . . . . . . . . depends on the peak cell rate and
the mapping setting
Jitter profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . periodic ramp
3
Jitter units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .µs, ms
Jitter resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 µs
1 In practice, the upper limit is given by the physical mapping.
2 This is the source model jitter. The jitter in the actual data stream is the sum of the source model jitter, the multiplex
jitter and the intrinsic jitter of the generator. The intrinsic jitter of the generator is largely determined by the mapping
and is hence strongly dependent on the physical cell rate.
3 Cell arrival times are reduced over a certain time interval until the set jitter amplitude is reached. A gap then occurs
in the cell stream to ensure that the correct mean cell rate is achieved.
Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . peak cell rate, mean cell rate,
burst size and cell jitter
Peak cell rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to 366792 cells/s
1
Peak cell rate units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cells/s, Mbit/s, kbit/s
Peak cell rate resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 cell/s
Mean cell rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to 366792 cells/s
1
Mean cell rate units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cells/s, Mbit/s, kbit/s
1 In practice, the upper limit is given by the physical mapping.