Moseley Associates Inc EVENTHD ユーザーズマニュアル
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2. System Description
© 2007 Moseley, Inc. All Rights Reserved.
602-14886-01, Rev. A
2.91+1 Protection
The Event HD supports 1+1 protection as an option for a critical link. In this
configuration, protection is provided in a single 1 RU chassis. The SDIDUTM contains two
power supplies and two modems. The power supply, ODU, IF/telemetry and modem are
power supplies and two modems. The power supply, ODU, IF/telemetry and modem are
protected. The digital framing and LIUs are not. One modem is referred to as the west
modem and the other as the east modem. 1+1 protection can be run in two modes called
modem and the other as the east modem. 1+1 protection can be run in two modes called
Protected Non-Diversity and Protected Diversity.
2.9.1Protected Non-Diversity (Hot Standby)
Figure 2-9 shows operation in Protected Non-Diversity mode, also called Hot Standby. In
this mode, one ODU at each location transmits to two ODUs at the other location. This
mode does not require the extra bandwidth or interference protection. It provides hitless
this mode, one ODU at each location transmits to two ODUs at the other location. This
mode does not require the extra bandwidth or interference protection. It provides hitless
receive switching and hot standby. The SDIDU
TM
automatically switches transmit ODU
upon appropriate ODU alarm or ODU interface error, minimizing transmit outage time.
w
Figure 2-9. 1+1 Protection in Non-Diversity Mode
2.9.2Protected Diversity
In Protected Diversity mode, the link between each pair of modems is the same, as
shown in Figure 2-10, providing complete redundancy. This arrangement requires
shown in Figure 2-10, providing complete redundancy. This arrangement requires
bandwidth for both links and non-interference between the links, but it provides hitless
receive and transmit switching. The SDIDU
receive and transmit switching. The SDIDU
TM
supports both frequency and spatial
diversity.