Redline Communications AN-50e, Руководство пользователя

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AN-50e
user manual
70-00033-01-03 Proprietary Redline Communications © 2005 September 2005
Page 20 of 100
The AN-50e system utilizes Redline's advanced Medium Access Control (MAC)
design to provide efficient transmission of data in both PTP and PMP modes. In
PMP mode, the MAC incorporates a proprietary polling algorithm to support
multiple subscriber stations from a sector controller. Multiple sector controllers
can be installed on a single rooftop or tower to provide multi-sector coverage.
A single sector AN-50e PMP implements a distributed wireless L2 switch, with
one uplink port located on the sector controller (master) distributing bandwidth to
a variable number of subscriber stations.
- Each subscriber station (remote-end) is considered a separate wireless link.
- Each configured wireless link adds to the switch one remote-end port that is the
Ethernet port on the corresponding subscriber station.
- Each link (remote-end) is assigned one ID that is used to manage both the
connection traffic and the wireless link.
- The switch supports one broadcast/multicast group called default group, which
is automatically assigned a fixed ID.
The AN-50e system uses time division duplexing (TDD) to transmit and receive
on the same RF channel. The sector controller schedules all downlink traffic and
uses a scheduled request/grant mechanism to arbitrate subscriber station requests
for uplink bandwidth. The sector controller controls all uplink and downlink traffic
scheduling, providing non contention-based traffic with predictable transmission
characteristics.
The AN-50e does not allow the operator to specify an exact Committed
Information Rate(CIR) value for each subscriber station connection. The CIR is
configured by selecting a QoS value that represents a range of CIR.
The CIR range represented by each QoS value can not be represented in a simple
lookup table. The operational QoS range is affected by factors including: link
budget (burst rate), registration period, number of active connections, and the
group multicast rate.
With multiple subscriber stations compete for bandwidth, the sector controller
ensures that bandwidth is allocated according to the assigned QoS values. For
example, during periods of peak bandwidth, the sector controller will allocate only
the provisioned CIR for each subscriber station connection.