Aviat Networks ECLIPSE EDGE, Руководство пользователя

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260-668080-001 Rev 002 March 2013 15
Eclipse Edge User Manual
Edge Dual ODU Protection
Link protection is provided by a dual ODU protection mechanism. A single IDUspe
connects to two ODUs to provide protection for the radio path, the ODUs, the ODU
cable, and the PoE injectors on the IDUspe.
Dual ODU protection can be configured for hot-standby, or space diversity. For
hot-standby single antenna operation, couplers are available with equal or unequal
losses.
• For equal loss the attenuation per side is nominally 3.5 dB (3.5 / 3.5 dB), which
applies to both the transmit and receive directions, meaning the additional total
one-way attenuation compared to a non-protected link is 7 dB.
• For unequal loss the attenuation is nominally 1.5/6.5 dB. They have application on
rain-affected bands, 13 GHz and above.
In protected mode, the Tx source signal is always available to both ODUs, with Tx
online control managed by a mute signal on the relevant (Tx offline) ODU.
• The default online transmitting ODU is the primary ODU .
• ODU1 is the primary ODU; ODU2 the secondary.
• Online Tx status can be changed in the System/Controls screen.
Both ODUs are online receiving.
• The Rx protection mechanism selects which Rx source (ODU) to use at any time to
send data to the line/customer.
• This selection process involves hitless (errorless) voting between the two Rx streams,
whereby the least errored stream is selected on a block-by-block basis.
Protection is provided for both Ethernet and PDH traffic.
As with non-protected 1+0 operation, only spe elements (IDUspe, ODUspe) can be
used at the ends of a protected Edge link.
The operating channels must be chosen from within the same diplexer option. If the
two ODUs are not from the same tuning/diplexer option interference may occur,
resulting in degraded link performance.
Protection Switching Conditions
Switching conditions for primary and secondary ODU operation apply only to the Tx
function. There are no Rx primary / secondary protection switch functions as both
ODUs are online receiving and forwarding to a common diversity bus. This applies to
both hot-standby and space diversity operation.
The primary ODU is biased to become the online transmitter on power up.
In instances where traffic recovery is not immediately possible, such as during a
complete rain fade, the IDUspe sends an AIS signal (all ones) to the customer
interface.