Installation guide

Table Of Contents

Cisco uBR7200 Series Universal Broadband Router Wireless Modem Card and Subsystem Installation and Configuration

78-6030-03

Command Reference

broadband fixed wireless systems have two settings for the amount of error-correction coding. The SINR

required for a link is reduced by 5 to 6 dB when the setting with the most error-correction coding is used

(see Table 8 and Table 9).

Multipath delay spread occurs when the signal arrives at the receiver by multiple paths with differing

path lengths. Signals that take longer paths will arrive later than signals that take shorter paths. The delay

spread is the difference between the time it takes for the shortest path signal and the longest path signal

to arrive. Typically, delay spread is the longest in urban areas with many buildings acting as reflectors.

Delay spread is more important when the direct path between antennas is blocked, making the delayed

signals stronger relative to the direct signal.

Both 6-MHz and 12-MHz bandwidths are available. For each of these bandwidths there are three

possible throughput settings: high, medium, and low. The low setting uses the most error-correction

coding and can handle the most multipath delay spread. The medium setting uses less error-correction

coding, but can still handle the most multipath delay spread. The high setting uses less error-correction

coding and can handle less multipath delay spread. Table 8 and Table 9 show that SINR tolerance is

influenced by the error-correction coding, and multipath tolerance is influenced by the cyclic-prefix

settings.

Table 8 12-MHz Bandwidth Values

Throughput Setting High Medium Low

Payload throughput 44.6 Mbps 38.7 Mbps 22.1 Mbps

SINR (single antenna)

AWGN channel 22 dB 22 dB 17 dB

Rayleigh fading channel 34 dB 34 dB 28 dB

SINR (dual antenna)

AWGN channel 19 dB 19 dB 14 dB

Rayleigh fading channel 24 db 24 dB 18 dB

Multipath delay spread tolerance 2.4 µs 7.8 µs 7.8 µs

Error-correction coding 7/8-rate 7/8-rate 1/2-rate

Cyclic prefix setting short long long

Table 9 6-MHz Bandwidth Values