User's Manual

DIB-500 R4.1 Product description
Constituents
62 Installation, Operation and Service Manual 90DIB500R41IM_FCC02 – 99.1
3.1.9.5 Fallback operation
The radio coverage of base stations is also ensured if the base station loses the con-
nection to an IP node (IPN) with Switching Controller Function (SCF). In this case, the
base station changes to fallback operation. In fallback operation, the base station in its
radio cell still maintains the Base Station Function (BSF). Even in fallback operation,
authentication and authorisation are ensured since the corresponding subscriber data
are stored in the base station.
The connection to other network constituents is not possible in fallback operation, the
following services and performance features, however, are available locally:
| Group calls
| Individual calls (semi-duplex and duplex calls)
| Transmission of SDS and status messages
| Class 2 and class 3 air interface encryption (encrypted voice and data communica-
tion)
| Authentication (with respect to the base station)
| Priority calls, emergency calls, pre-emptive priority calls
| Queue, depending on the priority level of the call
| Rejection of a call from/to an unknown subscriber
| Rejection with the reason "Busy" if the subscriber is already making a call or the pri-
ority of the incoming call is too low
| Configurable call time limit
| Inactivity timer (ending half-duplex calls after the configured inactivity time has
expired)
The fallback operation is signalled to the mobile stations, which take this information
into account when selecting radio cells. Fallback operation is the emergency operating
mode of base stations in ACCESSNET
®
-T IP networks with centralised switching archi-
tecture.
3.1.9.6 Stand-alone operation
The radio coverage of base stations with Switching Controller Function (SCF) in net-
works with distributed switching architecture continues to be ensured if they lose the
connection to all other network constituents with SCF. In this case the base station
switches to stand-alone operation.
In stand-alone operation, the base station in its radio cell will perpetuate the Base Sta-
tion Function (BSF) as well as all the other local services and gateways (Application
Gateway (AGW) and/or Packet Data Gateway (PGW)). As opposed to fallback opera-
tion, in stand-alone operation call detail records (CDR) will still be generated.
The stand-alone operation is signalled to the mobile stations, which take this informa-
tion into account when selecting radio cells. Stand-alone operation is the emergency
operating mode of base stations in ACCESSNET
®
-T IP networks with distributed
switching architecture.