Cambium PTP 670 Series, Руководство пользователя

Страница: 32 / 594

Chapter 1: Product description Wireless operation
Page 1-8
The Master ODU includes an Ethernet bridging function with address learning to forward
Ethernet data traffic via a wireless link to the appropriate Slave, based on the destination
address of the end-station reached through the Slave. Traffic with broadcast or unknown
unicast destination address is duplicated in the Master and forwarded on each of the links
separately.
The star of wireless links and the Ethernet bridging function in the Master together provide
LAN-like connectivity between the wired ports at up to nine ODUs. Data traffic forwarded from
a wired port on one Slave to a wired port on a different Slave is delivered via the Master ODU
and thus consumes wireless capacity in two different time slots.
The HCMP topology supports the following features:
•
Operating frequencies: 4800 MHz to 5875 MHz, 4900 MHz to 6050 MHz
•
Channel bandwidth: 20 MHz or 40 MHz
•
Range: Up to 40 km
•
Number of Slaves:
o
20 MHz: Up to four
o
40 MHz: Up to eight
•
Link symmetry: 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4, depending on bandwidth and number of
Slaves
•
Link optimization: IP
•
TDD synchronization using PTP-SYNC
•
Spectral efficiency: Up to 8.3 bps/Hz
•
Aggregate data capacity: Up to 338 Mbit/s
Synchronous Ethernet, IEEE 1588 Transparent Clock and TDM are not supported for the HCMP
topology in this release, but may be added in later releases.
Further reading
For information about… Refer to…
Wireless encryption in HCMP topology Wireless encryption on page 1-21
Capability upgrades for HCMP Capability upgrades on page 1-60
Configuring encryption in HCMP Wireless encryption on page 1-21
Configuring the Whitelist Authorization Control page on page 6-63
Time division duplexing in PTP wireless topology
TDD cycle
PTP 670 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.