Unit installation

Installation and Operation Manual Chapter 1 Introduction
FCD-E1 Overview 1-5
Timeslot Handling
When operating in any of the framed modes, FCD-E1 allows the user to configure
the routing of the individual timeslots for each channel, and for the sublink. The
routing can be modified during system operation, without disrupting the service to
users of timeslots that are not rerouted. FCD-E1 automatically connects the
timeslots in both the receive and transmit directions. The routing capabilities
depend on the port type:
• For the sublink, you can select the timeslots to be transferred between the
sublink and main links. A sublink timeslot is always routed to the main link
timeslot with the same number.
You can specify, for each sublink timeslot, the payload type (voice or data)
carried in the timeslot. This enables correct handling of timeslots and of the
associated signaling information during alarm conditions. An additional
difference between voice and data timeslots is that voice timeslots can be
connected only to a link, which uses G732S multiframes.
To expedite the routing, FCD-E1 supports a “bundle” routing mode, called
“sequential bundle” routing mode. One “bundle” (group of consecutive
timeslots, identified by the number of the starting timeslot and the total number
of timeslots) can be routed to the corresponding main link timeslots, where
they are inserted in the main link frame sequentially, in consecutive timeslots.
• For data channels, the user can either individually select the main link
timeslots in which the user’s data is to be inserted, or can use the “bundle”
routing mode. Timeslots connected to data channels are always defined as
data timeslots.
To help you route correctly timeslots, FCD-E1 automatically checks the validity of
the user’s inputs, and reports, by means of error messages, inconsistencies and
invalid selections. The conditions reported include:
• Attempt to allocate to user’s traffic timeslots that must be reserved for system
use: timeslot 16 when G732S multiframes are used, or a timeslot dedicated to
the management traffic between two FCD-E1 connected in a link.
• Total bandwidth requested exceeds the available main link bandwidth:
 Maximum 31 timeslots
 Maximum 30 timeslots when using G732S multiframes or G732N
multiframes with a timeslot dedicated to management
 Maximum 29 timeslots when using G732S multiframes and a timeslot
dedicated to management.
The bandwidth carried by the available timeslots depends on the basic data
rate selected by the user (56 or 64 kbps).
• Number of timeslots assigned to a data channel does not match the number
required to support the specified channel data rate.
• Two or more timeslots are mapped to any given main link timeslot.
• Timeslots specified as voice timeslots are routed to a link, which uses G732N
multiframes.