Cambium Networks PTP 650 Series, Руководство пользователя, Страница: 27 / 395

Chapter 1: Product description Wireless operation
Wireless operation
This section describes how the PTP 650 wireless link is operated, including modulation modes,
power control and security.
Time division duplexing
TDD cycle
PTP 650 links operate using Time Division Duplexing (TDD). They use a TDD cycle in which the
ODUs alternately transmit and receive TDD bursts. The TDD cycle is illustrated in
Figure 2 . The
steps in the cycle are as follows:
1 The TDD master transmits a burst to the TDD slave.
2 A delay occurs as the master-slave burst propagates over the link.
3 The slave receives the burst from the master.
4 The slave processes the master-slave burst.
5 The slave transmits a burst to the master.
6 A delay occurs as the slave-master burst propagates over the link.
7 The master receives the burst from the slave.
8 The master transmits the next burst to the slave.
TDD frame parameters
The TDD burst duration varies depending on the following:
•
Channel bandwidth
•
Link range
•
Link optimization mode
•
Link symmetry
•
Offered traffic loading.
The TDD frame duration varies depending on the following:
•
TDD burst duration master-slave.
•
TDD burst duration slave-master.
•
Link range.
Page
1-6