User guide

Understanding Canopy Networks March 2005
Through Software Release 6.1
Issue 1 Page 61 of 425
Canopy System User Guide
7.1.5 Canopy Slot Usage
The frame illustrated in Figure 22 shows both packet fragments (yellow) and unused slot
space (red) typical of uplink traffic. Packet sizes smaller than 64 bytes cause unused slot
spaces.
Figure 22: Uplink data slot usage
The following statistics apply to Canopy frame slot usage:
◦ Slot capacity is 64 bytes.
◦ The optimum Ethernet packet size is 1518 bytes.
◦ The maximum downlink throughput for one AP to one SM is 1800 pps.
◦ The maximum uplink throughput for one AP to one SM is 300 pps.
◦ The maximum backhaul throughput is 3000 pps.
7.1.6 Data Transfer Capacity
Canopy modules use Time Division Duplex (TDD) on a common frequency to divide
frames for uplink (orange) and downlink (green) usage, as shown in Figure 23.
Figure 23: TDD dividing Canopy frames
7.1.7 QoS Parameters
Canopy point-to-multipoint links use the following four QoS parameters for bandwidth
management:
◦ Sustained Uplink Data Rate (kbps)
◦ Uplink Burst Allocation (kb)
◦ Sustained Downlink Data Rate (kbps)
◦ Downlink Burst Allocation (kb)
You can independently set each of these parameters per AP or per SM.