User Manual

Table Of Contents
Chapter 4 - Operation and Administration
BreezeACCESS VL System Manual
188
A special algorithm for graceful degradation is incorporated into the AU, ensuring
that the degradation of performance for each individual Subscriber Unit is
proportional to its CIR.
The MIR/CIR algorithm uses buffers to control the flow of data. To balance the
performance over time, a special Burst Duration algorithm is employed to enable
higher transmission rates after a period of inactivity. If no data intended for a
certain SU (in the AU) or for the AU (in an SU) is received from the Ethernet port
during the last N seconds, the unit is allowed to transmit to this destination N
times its allowed IR value without any delay. For example, if the Burst Duration
is set to 0.5 second (or more), then after a period of inactivity of 0.5 seconds up to
128 Kbits x 0.5 = 64 Kbits may be transmitted to a unit whose IR is 128 Kbps,
without any delay (provided overall conditions in the wireless link allow this
burst).
4.2.6.6.2.1 MIR: Downlink (SU only)
Sets the Maximum Information Rate of the downlink from the AU to the SU. The
MIR value cannot be lower than the corresponding CIR value.
Available values range and default value are shown inTable 4-
12.
The actual value will be the entered value rounded to the nearest multiple of 128
(N*128).
4.2.6.6.2.2 MIR: Uplink (SU only)
Sets the Maximum Information Rate of the up-link from the SU to the AU. The
MIR value cannot be lower than the corresponding CIR value.
Available values range and default value are shown in Table 4-
12.
The actual value will be the entered value rounded to the nearest multiple of 128
(N*128).
4.2.6.6.2.3 CIR: Downlink (SU only)
Sets the Committed Information Rate of the downlink from the AU to the SU. The
CIR value cannot be higher than the corresponding MIR value.
Available values range and default value are shown in Table 4-
13.
The actual value will be the entered value rounded to the nearest multiple of 128
(N*128).
4.2.6.6.2.4 CIR: Uplink (SU only)
Sets the Committed Information Rate of the uplink from the SU to the AU. The
CIR value cannot be higher than the corresponding MIR value.
Available values range and default value are shown in Table 4-
13.