Rev. 2.4
12
PMC Modules
User’s Manual
6 Q&A
Q1. How to select CO side and CPE side mode PMC?
A1.
Referring to the figure below, the PMC B module (nearest to IP camera) is the CO
side and PMC A module (nearest to control center) is the CPE side for valid
operation bandwidth.
Q2. How to
identify
fast and interleaved mode?
A2.
Fast mode guarantees a minimum end to end latency of less than 1 ms.
Interleaved mode provides protection from any impulse noise with duration of less
than 250
μ
s. Interleaved mode has a maximum end to end latency of 10 ms.
Interleaved mode is the default mode.
Q3. How to
select
target data rate and target SNR margin:
A3.
User can select fixed SNR margin (9 dB) or fixed target data rate. When fixed SNR
margin is selected, the systems will maintain the SNR margin at 9 dB across all
usable loop length. When fixed target data rate is selected, the system will lock the
data rate at 50Mbps/30Mbps whenever the calculated SNR margin is higher than
9 dB. This provides the best system stability and is the default mode.
Q4.
Why PMC modules cannot link each other after training?
A4:
1) A pair of PMC modules should consist of a CO side mode module and a CPE
side mode module. They cannot be of the same mode modules.
2) RJ-11 jack and connector may have loose contact.
3) The distance between 2 PMCs modules should not exceed 2Km.
RJ45
RJ11 (2km)
PMC A
PMC B
RJ45
