User's Manual

SKYPILOT NETWORKS CONFIDENTIAL AND PROPRIETARY
Page
SKYPILOT NETWORKS CONFIDENTIAL AND PROPRIETARY
6
2 Network Architecture
The SkyPilot CPE (SC1050) combines with the Gateway (GW1050) and Seed (SD1050)
to create a robust, high capacity wireless network. All wireless links within the network
are established and optimized automatically. Seed units allow for expanded coverage and
permit multiple paths through the network. A highly efficient routing algorithm selects
the best path for user traffic and heals around any network failures.
2.1 Link Establishment
A Gateway is configured for a given channel within the 4.9 GHz band and signals its
presence through the use of a periodic beacon message transmitted on that configured
frequency. Seeds that have successfully connected to the network also transmit a periodic
beacon message.
Upon power-up, the CPE listens for beacon messages generated by the Gateway and
Seeds. The receive signal strength of these beacons is indicated by the LEDs. This LED
indication allows the installer or end-user to position the CPE for optimum link
performance. The CPE and Gateway or Seed automatically complete link optimization.
This ensures the selection of optimal Gateway/Seed antenna and modulation rate. The
SkyPilot units support modulation rates of 6-54Mbps and the highest, reliable rate shall
be selected through the exchange of test packets. Note that established links are
continually monitored and periodically optimized.
2.2 Bandwidth Allocation
The SkyPilot system implements a synchronization of the 802.11 protocol. This
synchronization allows for the establishment of individual links between nodes utilizing a
unique timing and antenna combination. In addition, highly accurate traffic rate and jitter
control is enabled.
The SkyPilot system provides rate control for subscriber traffic both in the downstream
(Gateway to CPE) and in the upstream (CPE to Gateway) direction. The maximum rate
downstream and upstream rate can be specified for each subscriber. In conditions of over-
subscription when the overall bandwidth demand is higher than the system capacity, the
individual subscriber data rates will be reduced proportionately. i.e. a configured 2Mbps
is reduced to 1.5Mbps while a configured 1Mbps rate is reduced to 750kbps.