Chapter 1: Product description
Wireless operation
Page 1-18
For information about…
Refer to…
Effect of modulation mode on system
threshold, output power and link loss
System threshold, output power and link loss
page
How to configure modulation modes
on page
Modulation mode when the ODU is armed
Checking that the units are armed
How to view the transmit and receive
modulation modes
System counters (PTP topology)
MIMO
Multiple-Input Multiple-Output (MIMO) techniques provide protection against fading and
increase the probability that the receiver will decode a usable signal. When the effects of MIMO
are combined with those of OFDM techniques and a high link budget, there is a high
probability of a robust connection over a non-line-of-sight path.
The PTP 670 transmits two signals on the same radio frequency, one of which is vertically
polarized and the other horizontally polarized. Depending on the channel conditions, the PTP
670 will adapt between two modes of operation:
•
Dual Payload: When the radio channel conditions allow, the PTP 670 will transmit two
different and parallel data streams, one on the vertical channel and one on the horizontal
channel. This doubles the capacity of the PTP 670.
•
Single Payload: As the radio channel becomes more challenging, the PTP 670 has the
ability to detect this and switch to a mode which transmits the same data stream on both
vertical and horizontal channels. This provides polar diversity and is another key feature
which allows the PTP 670 to operate in challenging non- line of sight radio channels.
Lower order modulations (BPSK 0.63 up to QPSK 0.87) only operate in single payload mode.
Higher order modulations (16QAM 0.63 to 256QAM 0.81) are available in single payload mode
and dual payload mode. The switching between modes is automatically controlled by the
adaptive modulation feature described in
Note
The system automatically chooses between dual and single payload to try to increase
the capacity of a link. However the user can disable the dual payload mode, forcing
the more robust option of single payload.
Further reading
For information about…
Refer to…
How to configure dual or single payload
on page
Содержание PTP 670 Series
Страница 1: ...F Cambium PTP 670 Series User Guide System Release 670 02 50 ...
Страница 349: ...Chapter 5 Installation Installing an SFP Ethernet interface Page 5 52 Correct Incorrect ...
Страница 405: ...Chapter 6 Configuration and alignment System menu Page 6 46 Figure 151 LAN Configuration page PTP topology TDM support ...
Страница 406: ...Chapter 6 Configuration and alignment System menu Page 6 47 Figure 152 LAN Configuration page PTP topology SFP support ...
Страница 408: ...Chapter 6 Configuration and alignment System menu Page 6 49 Figure 154 LAN Configuration page HCMP topology ...
Страница 416: ...Chapter 6 Configuration and alignment System menu Page 6 57 Figure 156 QoS Configuration page IP MPLS ...
Страница 445: ...Chapter 6 Configuration and alignment Management menu Page 6 86 Figure 173 Time Configuration page SNTP enabled ...
Страница 551: ...Chapter 7 Operation System statistics Page 7 64 Figure 250 Main Port Counters page when main port is bridging traffic ...