Chapter 1: Product description
Wireless operation
Page 1-10
Link Scheduler
The PTP 550 series provides three configuration options for apportioning the available capacity
between the two link directions.
•
75/25 – The capacity in the direction Master to Slave comprises 75% of available TDD
frame, and the capacity in the direction of Slave to Master comprises 25% of available TDD
frame.
•
50/50 (Symmetric) - The capacity in the direction Master to Slave comprises 50% of
available TDD frame, and the capacity in the direction of Slave to Master comprises 50% of
available TDD frame.
•
30/70 – The capacity in the direction Master to Slave comprises 30% of available TDD
frame, and the capacity in the direction of Slave to Master comprises 70% of available TDD
frame.
OFDM and channel bandwidth
The PTP 550 transmits in two channels using Orthogonal Frequency Division Multiplexing
(OFDM). This wideband signal consists of many equally spaced sub-carriers. Although each
sub carrier is modulated at a low data rate using conventional modulation schemes, the
resultant data rate from all the sub-carriers is high.
The channel bandwidth of the OFDM signal is 20 MHz, 40 MHz or 80 MHz, based on operator
configuration.
Each channel is offset in center frequency from its neighboring channel by 5 MHz. PTP 550
supports 5 MHz channel separation / guard band between the two radio interfaces (5MHz
separation between the two operating band edges). PTP 550 does not allow operation with
two overlapping channels.
Note
The Channel Bandwidth must be configured to the same value at both ends of the link
for each channel. Not all channel bandwidths are available in all regulatory bands.
Further reading
For information about…
Refer to…
Channel bandwidths per frequency band
General wireless specifications
How to plan for channel bandwidth