Inputs
The 5548C TSG uses a universal INput Card (INC) designed to reduce spare counts. Each Input card can accept up to four signals and can be 1:1 protected with an adjacent identical “B†card. Two input groups (therefore four slots) are available for Input Cards, giving flexibility from 4 unprotected inputs (one card) to 8 protected
GPS Modules*
In addition to line input card, one or two GPS input cards can fitted to meet Stratum 1 requirements without the need of installing and managing external receiver(s) or Cesium clock. This allows the simplification of the sync plan by flattening the sync distribution hierarchy and results in a reduction of the overall provisioning, operating and maintenance costs.
The presence of GPS input also gives access to precise time information that can distributed via NTP. Additionally, 5548C can accept any external GPS reference as one on the input Line of the INC.
Input Selection
The active reference input is selected among the set of eligible input signals based on one of the following criteria:
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Priority table
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SSM value
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Performance Threshold mask
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User selection
Tracking and Holdover
This card forms the beating heart of the OSA 5548C TSG. The input reference jitter and wander are filtered by a high quality oscillator with DDS technology. Two types of oscillator are available:
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Rubidium (Rb)
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Double Oven Quartz (OCXO)
Pass-through
In the extreme case of total failure of both oscillator cards or if they are pulled out, the pass-through feature of the 5548C TSG allows to still keep the office alive. In this case synchronization is obtained from one DS1 input reference of the first TNC’s group and distributed without filtering to the output section.
Outputs
The 5548C TSG uses a universal Output Card of 20 outputs that will configure itself automatically when detecting the output tile set. Output cards slots are, like all the other functionalities on this TSG, separated in intuitive A and B groups (adjacent cards slot).
The 5548C 6U TSG counts 10 groups of outputs, giving you the flexibility from 20 unprotected outputs to 200 protected outputs on one shelf (and the flexibility of having some outputs protected and some unprotected).
The 5548C TSG provides maximum flexibility towards different interconnection requirements with its wide choice of modular tile sets.
Performance Measurement
All active inputs are constantly measured against the current output reference with 1ns resolution. The local processing of performance data presents the data in a way that reduces network overhead for remote retrieval. The computed MTIE and TDEV curves are used internally for the input selection compared to standard masks to raise alarms if the curves are out of limits sent to the management station(s) for display, user validation , and storage.
Time Code Card - NTP
Time Output cards allow precise time distribution when at least one GPS card is installed. This is a major advantage compared to having to additionally install and manage an external receiver with its GPS antenna and cabling. The Time Code Card - NTP provides full NTP time server functionality on a separate 10 BaseT RJ-45 connector. Time output cards can be fitted into any main output card slot.
DS1 Re-Timing
In association with the OSA 5242 Retimer, the OSA 5548C SSU provides up to 8 retiming channels. Configurable alarm thresholds can be set via management software in terms of slips per hour/day/week. This allows continuous monitoring and immediate detection of synchronization problems on the incoming traffic signals
Expansion or remote shelves*
Up to 4 expansion shelves can be chained to the main shelf for a total of 1000 outputs, optionally protected 1:1. Chaining of the expansion shelves is redundant in order to ensure maximum reliability.
Management
The management card provides connectivity with local and remote synchronization management systems via a TL1 interface over RS-232 (local) and TCP/IP (remote).
OSA Local Manager and SyncView Next Generation Management software provide, locally and remotely, powerful fault, configuration, accounting/inventory, performance and security management functions through an intuitive graphical user interface.
Local alarm information is provided as:
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Internal buzzer (audible)
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Relay contacts (electrical)
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Status LED’s on front panel (visual)
Third party equipment can easily be managed through a set of 10 electrical alarm collection inputs; a specific user-configurable alarm message can be associated to each alarm input. As a future option, the 5548C will also be manageable directly by SNMP through SyncView Plus NMS proxy agent.
Simplified Maintenance
TSG and Expansion Shelves share the same cards; this reduces homologation activity, stock of spare parts as well as overall administrative complexity and results in reduced cost of ownership. All cards are easily reprogrammable via a simple software download and managed via a global shelf release.