osta cd-r compatibility study results from phase 2 - OSTA - Optical ...

CD-R Compatibility Study – Phase 2
With properly functioning systems, a very high degree of compatibility was
observed. Some of the highlights include:
• Results of Phase 2 testing showed improvement over Phase 1, where similar
testing occurred (written media and reader interchange compatibility). The written
discs and writers did not show any significant deviations from the global
population statistics. The average BLER from Phase 2 was 6.29 counts per
second (cps), which was an improvement over the 8.3 cps of Phase 1 testing.
• The new tests for blank media showed that pre-recorded parameters (land and
groove reflection, push-pull, radial contrast and wobble carrier-to-noise ratio)
show fairly small radial dependency characteristics for each manufacturer’s
process. The consistency of the individual manufacturing processes shown in the
measured parameters was impressive. Almost all parameters showed standard
deviations less than two times the measurement repeatability. With the exception
of push-pull, all measured parameters were within the Orange Book limits for
almost all blank media measured.
• A subset of all the written discs was read by thirteen CD-ROM readers that had
speed ratings from 8X to 16X. The subset was comprised of the “worst” disc
from each media/writer combination as measured by BLER. Even after selecting
these “worst example” discs, the “User Convenience” index of the discs tested
was 96% compared to replicated or pressed CD-ROMs used in the same readers.
In summary, it was found that the CD-R industry shows clear signs of reaching maturity
as evidenced by the absolute values and the consistency of the measured media
parameters. The CD-R manufacturing processes used appear to converge on much tighter
specifications than formally required, which is another sign of a mature industry.
4.0 Logistics and Testing Issues
Some delays were encountered in the delivery of both blank and recorded media, and this
caused significant complications in testing and measurement. Additionally, some media
was recalled by one of the manufacturers and then replaced. This caused a ripple effect
throughout the entire logistics and testing with resultant delay of completion and
reporting.
Reporting delays were compounded by incompatible test equipment report formats and
non-compatible graphic file formats.
It has to be emphasized that all participation was voluntary, and it became extremely
“difficult” for personnel at various companies to devote large amounts of unscheduled
time and resources to such activities. In total, more than 1,000 hours of testing were done
by the Phase 2 participants.
4 © OSTA – Optical Storage Technology Association