User Manual
Product information and planning
9500 MPR Rel. 3.1
3DB18809AAAA Issue 1172/980
Depending on the channel spacing value, the maximum number of E1 that can be provisioned is (refer
to
Table 2.):
– Channel spacing of 7 MHz: 4 x E1
– Channel spacing of 14 MHz: 8 x E1
– Channel spacing of 28 MHz: 18 x E1
The remaining capacity is devoted to other types of traffic such as Ethernet best effort.
When RSL (received signal level) value decreases, modulation scheme is downgraded first from 64QAM
to 16QAM: the traffic with lower priority exceeding 16QAM bandwidth is dropped and all the E1s are kept.
As soon as the RSL value further decreases, modulation scheme is downgraded to 4QAM and the whole
traffic exceeding 4QAM bandwidth is dropped while the E1s are kept.
Figure 81., Figure 82. and Figure 83. here below show how the system operates, in case of modulation
changes when admission control is enabled (case of 28 MHz bandwidth).
Figure 81. Example of traffic in case of 28MHz bandwidth and Admission Control Enabled
In this case, the operator has commissioned 13xE1’s and enabled the Admission Control. There are two
other kinds of traffic provisioned, Ethernet traffic #1 and Fast Ethernet traffic #2. Furthermore, Ethernet
traffic #1 has a higher priority than Fast Ethernet traffic #2.
The 13xE1’s are saved even in the case of a degradation of the modulation down to 4QAM. Remaining
available capacity is used to transmit other kinds of traffic.
When the modulation is degraded from 64QAM to 16QAM (Figure 82.), the E1 flows are kept whilst the
Ethernet traffic with lowest priority (Fast Ethernet traffic #2) is reduced.
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