Nova Engineering NovaRoam™ 900 Spread Spectrum Transceiver User’s Manual Nova Engineering 5 Circle Freeway Drive Cincinnati, OH 45246 513 860 3456 FAX 513 860 3535 www.nova-eng.com © 1999 Nova Engineering, Inc. All Rights Reserved.
1.0 Introduction Nova Engineering’s NovaRoam™ 900 is a complete direct sequence spread spectrum (DSSS) transceiver tailored for industrial applications that operates in the 915MHz industrial, scientific, and medical (ISM) frequency band. This product can be used for multiple access networking, point to point, or broadcast operation. The DSSS waveform results in enhanced immunity to interference, yielding increased link reliability, especially in congested areas.
Nova Engineering also offers professional NovaRoam™ 900 installation at the user’s discretion. This service provides the added performance benefit of generating a site survey to achieve the most reliable links possible. Nova Engineering’s custom design expertise identifies the optimum RF channels, antennas, antenna heights, operating mode, and network topology. NOTE This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to Part 15 of the FCC Rules.
Table 2 Mode 1 2 3 4 5 6 7 NovaRoam™ 900 Channels Channel Frequency (MHz) Minimum Maximum 906 924 906 924 906 924 909 921 909 921 909 921 909 921 though the RF channel resolution is 0.5MHz, the channels need to be separated by at least the signal bandwidth when attempting to operate multiple NovaRoam™ 900 transceivers in overlapping regions. The signal bandwidth also limits the channels that may be selected since the FCC Rules prohibit the spectrum from extending beyond the 902 to 928MHz boundaries.
The six short elements of the Yagi should be oriented vertically in order to match the polarization of other antennas in the NovaRoam™ 900 network. The Yagi is therefore used to reject strong interference that is not along the line of sight between the source and destination transceivers. The obvious disadvantage of employing a Yagi is that it cannot be used when one of the NovaRoam™ 900 units is mobile.
NovaRoam™ 900 Transceiver Specification Electrical Parameters Specification Waveform Direct Sequence Spread Spectrum Frequency Range 902-928MHz ISM Band Modulation Type Differential BPSK or QPSK Spread Bandwidth 9.0MHz or 2.1MHz (User Programmable) Channel Spacing 500kHz Sensitivity -101dBm at 159kbps channel burst rate for 10-5 BER Adjacent Channel Rejection 45dB at 4.0MHz offset IF Rejection 70dB Image Rejection 70dB LO Leakage -80dBm Channel Burst Data Rate 7 Programmable Data Rates from 21kbps to 1.
