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Cisco uBR7225VXR Universal Broadband Router Hardware Installation Guide
OL-17309-02
Appendix B RF Specifications
Electrical Input and Output
Electrical Input and Output
The information in Table B-9 and Table B-10 relates to both DOCSIS and EuroDOCSIS specifications.
Table B-9 Electrical Input to the Cable Modem
Parameter Value
Center frequency
• DOCSIS: 91 to 857 MHz ±30 kHz
• EuroDOCSIS: 112 to 858 MHz ±30 kHz
Level range (one channel)
• DOCSIS: –15 dBmV to +15 dBmV
• EuroDOCSIS: 43 to 73 dBmicroV for QAM-64
47 to 77 dBmicroV for QAM-256
Modulation type QAM-64 and QAM-256
Symbol rate (nominal)
• DOCSIS: 5.056941 Msym/sec (QAM-64) and 5.360537
Msym/sec (QAM-256)
• EuroDOCSIS: 6.952 Msym/sec for QAM-64 and
QAM-256
Bandwidth
• DOCSIS: 6 MHz
–
18% square root raised cosine shaping for QAM-64
–
12% square root raised cosine shaping for QAM-256
• EuroDOCSIS: 8 MHz
–
15% square root raised cosine shaping for both
QAM-64 and QAM-256
Total input power (40–900 MHz) < 30 dBmV (90 dBmicroV)
Input (load) impedance 75 ohms
Input return loss
• DOCSIS: > 6 dB (88–860 MHz)
• EuroDOCSIS: > 6 dB (85–862 MHz)
Connector F connector per ISO-169-24 (common with the output)
Table B-10 Upstream Electrical Output from the Cable Modem
Parameter Value
Frequency
• DOCSIS: 5 to 42 MHz edge to edge
• EuroDOCSIS: 5 to 65 MHz edge to edge
Level range (one channel)
• QAM-16: +8 to +55 dBmV (+68 to +115 dBmicroV)
• QPSK: +8 to +58 dBmV (+68 to +118 dBmicroV)
Modulation type QPSK and QAM-16
Symbol rate (nominal) 160 ksym/sec
320 ksym/sec
640 ksym/sec
1280 ksym/sec
2560 ksym/sec