Exalt Communications, Inc.
EX-5r Installation & Management
5000007
11
2006-05-17
The following generalizations can be made with regards to these factors:
•
The shorter the TDD Frame Size, the lower the latency
•
The shorter the Link Distance, the lower the latency, the higher the throughput
•
The longer the TDD Frame Size, the higher the throughput
•
The higher the Bandwidth, the higher the capacity
•
The higher the Mode, the higher the capacity
If there are no T1/E1 interfaces connected, all T1/E1 ports should be disabled. This
will shift the available throughput to the Ethernet interface.
If a selected combination of Link Distance, Frame Size, Bandwidth and Mode cannot
support all four (4) T1 or E1 ports, the ports that cannot be supported will be disabled
automatically. Priority is placed on the T1/E1 port number. That is, the first port to be
disabled, if necessary, is Port 4. More information on T1/E1 configuration can be
found in Section 5.9.
2.5 Link
Orientation
and Synchronization
Link orientation refers to the Radio A and Radio B placement in your network. Link
synchronization refers to using external or internal timing to coordinate multiple links.
As mentioned, for every link, one end of the radio link must be configured as Radio A, while the
other end configured as Radio B. In single-link systems, it does not matter which end of the
system is mounted at which end of the link, and there is typically no requirement for any link
synchronization.
Link orientation and synchronization are more important for networks that have any site(s)
where there is more than one EX-5 link or for EX-5 sites that are very close to one another.
Collocated radio terminals should be configured for the same link orientation. That is, all radios
at the same location should be Radio A or all radios should be Radio B.
In addition, it can be advantageous to utilize link synchronization for collocated links. The EX-5r
allows the use of an optional GPS synchronization kit or internal synchronization. This
synchronization controls the transmitter and receiver frame timing so that collocated radios are
transmitting at the same time and receiving at the same time. This can substantially reduce the
opportunity for self-interference. Without synchronization, collocated radios may be transmitting
and receiving at the same time, and thus, near-end interference may occur.
It is not always necessary to synchronize collocated radios. If antennas are
substantially separated, or blocked from one another, and/or frequency separation
tuning is used, the opportunity for near-end interference can be eliminated.