User's Manual

WiN7000 cBST Product Description | 21
correct errors that cannot be corrected by the FEC, by having the erroneous information
resent. This significantly improves the bit error rate (BER) performance for a similar threshold
level.
The WiN7000 supports two Forward Error Correction (FEC) types: CC and CTC.
Convolution Coding (CC) error correction is enabled for all traffic rates. This low-level
process can correct bursts of errors in received messages and reduce the number of
retransmissions.
Convomotional Turbo Code (CTC) error correction is supported for all traffic rates. The CTC
has better performance than the CC.
2.4.7 Time Synchronization
When operating two or more collocated base stations, transmitter operations MUST be
synchronization to minimize inter-sector interference and inter sites interferences due to the
TDD use. Each base station sector has a GPS receiver or optionally IEEE1588 compliant
synchronization module. External GPS antenna must be connected to the GPS port located on
the connector panel when a GPS receiver option is used.
2.5 Deployment Models
The base station supports point to multipoint (PMP) deployment scenario.
2.5.1 PMP Deployment
When deployed in a PMP configuration the base station establishes bi-directional links to
more than one subscriber. PMP deployments typically use a wide beam (sector) antenna at
the base station and a narrow beam antenna at the subscriber. Service flows are used to police
service-level agreements for each subscriber.
2.5.2 Non Line-of-Sight
The Win-Max
TM
product family supports line-of-sight (LOS) and non line-of-sight (NLOS)
operation. A clear LOS link has no obstacles within 60% of the first Fresnel zone of the direct
path.
A wireless link is considered non-LOS if natural or man-made structures block the visible
path between the base station and the subscriber. In this case, a wireless link can be
established only if a reflective path can be established between the base station and
subscriber.