User's Manual

260-668066-003 Rev 002 October 2001 3-9
Eclipse Installation Manual
Eclipse IRU 600
The IRU 600 is a 3RU rack-mounted transceiver unit for co-location with an INU/
INUe as an all-indoor installation.
IRU 600 is 1+1 optimized with provision for two RFUs (Radio Frequency Unit) and a
companion filter-based ACU (Antenna Coupler Unit).
Transmit power output is limited to a maximum 29.5 dBm at the antenna port to
ensure compliance witt the conducted power limit (1W, 30 dBm) in FCC CFR 47, Part
15.247.
The ACU design incorporates an optional expansion port to allow other radio links onto
its waveguide feed for co-path operation.
The IRU 600 also supports 1+0 repeater (back-to-back) operation. The links may be in
the same or different bands.
Protected/diversity options include:
• 1+1 hot-standby, single antenna, with equal or unequal split.
• 1+0 hot-standby-ready.
•Space diversity (dual antennas) with common or split Tx.
IRU 600 and IRU 600v2
IRU 600v2 incorporates a transmit coaxial RF switch in place of the Tx coupler used
with IRU 600 (V1) for 1+1 hot standby and space diversity applications. The changes
include a new RFU (RFUv2). IRU 600v2 also adds a transmit monitoring port. V2
operation requires SW release 6.02 or later.
Tx Coaxial Switch: IRU 600v2
Primary benefits of the Tx coaxial switch are reduced power loss and faster Tx
protection switch times.
• It avoids the losses associated with a Tx coupler/combiner.
• With the Tx coaxial switch (relay) there is no A-side versus B-side consideration
required as the loss is not more than 0.5 dB on both.
• Average recovery times of 50 ms compared to times approaching 200 ms for the
Tx-mute/unmute operation of the coupler-based (IRU 600 V1) solution.
• Times apply to full MHSB operation (standby Tx on), and muted standby Tx mode
(standby Tx on Tx mute). The standby Tx is terminated into a dummy load via the
Tx switch.
MHSB mode increases power consumption as both transmitters are fully active - both
online and offline Tx status is captured in real time. Where lower power consumption
is the priority, an option is provided to mute the offline Tx. For power consumption
data See INU Power Supply on page 1.
• With MHSB operation both A-side and B-side transmit are fully monitored.