User Manual
Product information and planning
9500 MPR Rel. 3.1
3DB18809AAAA Issue 1174/980
Depending on the channel spacing value, the maximum number of E1’s that can be provisioned is (refer
to
Table 2.):
– Channel spacing of 7 MHz: 8 x E1
– Channel spacing of 14 MHz: 18 x E1
– Channel spacing of 28 MHz: 37 x E1
The remaining capacity is devoted to other types of traffic such as Ethernet best effort.
When RSL (received signal level) value decreases, the modulation scheme is downgraded first from
64QAM to 16QAM and all E1 flows are kept because there is enough bandwidth to transmit them. When
the modulation further degrades to 4QAM, all E1 flows are dropped because there is no way to define any
kind of priority among them. The remaining bandwidth is filled with other traffics.
N.B. It might happen that some E1(s) are temporarily up and transmitting, but this is a random behav-
iour without any predefined mechanism, there is no control at all performed on the E1 links.
This feature addresses the need of transmitting a high number of E1’s, without giving up the benefits of
adaptive modulation for Ethernet traffic.
Figure 84., Figure 85. and Figure 86. show how the system operates in case of modulation changes when
admission control is disabled (case of 28 MHz bandwidth).
Figure 84. Example of traffic in case of 28MHz bandwidth and Admission Control Disabled
In this case, the operator has commissioned 32xE1’s and chosen to disable the Admission Control. These
32 xE1’s are kept as long as the modulation scheme is degraded down to 16QAM.
Other kinds of traffic are transmitted according to the available capacity and the priority defined beyond
them.
When the modulation is downgraded to 16QAM, all E1 flows are kept whilst the other traffic is reduced.
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