User guide

Canopy System User Guide
pmp-0229 (Mar 2013)
81
Chapter 7: Link Characteristics
Understanding Bandwidth Management
Downlink Frame
A full frame consists of a downlink frame and an uplink frame. The downlink frame transmitted
from the AP consists of
• a beacon
• an uplink map that tells each SM which slots it can use in the next uplink frame
• broadcast and per-SM data.
Each SM retrieves broadcast data and data addressed to that SM and passes that data through its
Ethernet port to connected devices.
The beacon communicates
• timing
• ratio of uplink to downlink allocation
• ESN of the AP
• color code
• protocol (point-to-point or point-to-multipoint)
• number of registered SMs
• frame number
• number of reserved control slots
• air delay, subject to the value of the Max Range parameter in the AP.
Uplink Frame
The uplink frame transmitted from the SMs consists of
• per-SM data in slots assigned by the uplink map in the previous downlink frame
• bandwidth requests for data slots in future uplink frames.