Specifications

Base Site Controller
iDEN® System
August 08, 2000 68P81095E55-E 2-19
BSC Implementation
The BSC may be implemented in several ways depending on the network
configuration, the mix of legacy systems with new devices, and the location of the
hardware that converts the radio link to the network link. The configurations are:
•Non-enhanced
• Enhanced BSC remote located
• Enhanced local located
Non-enhanced
BSC
Implementation
Slower and more legacy system may use the BSC for both control and transcoding
functions in the same cabinet to form an integral BSC/CP/XCDR. This
implementation uses one set of hardware to provide all interface, conversion and
control functions. In an non-enhanced BSC, all traffic and signalling passes through
both the BSC-CP and the BSC-XCDR. The advantage of this method is lower cost
and the ability to locate the cabinets remote from the Mobile Switching Office
(MSO) and then use larger transport facilities to connect them (Figure 2-11). The
disadvantage is limited capacity, redundancy and growth.
Figure 2-11 BSC Implementations
Enhanced BSC-
XCDR Remote
Located
An Enhanced remote located implementation distributes the control, conversion and
interface hardware. The BSC-CP may be remotely located amid several EBTSs and
handle the processing for those sites. While the BSC-XDCR is located at the central
location. This offloads MSO space and allows larger transport facilities in cases
were the MSO location is overcrowded. The disadvantages of this implementation
are remote maintenance, transport issues and a potential circuit under-utilization.
Enhanced Local
Located
An MSO co-located implementation places the BSC-CP/XCDR at the same location
as the MSO. XCDRs may still be multi-threaded. Local location centralizes the
radio link conversion function at the MSO. This impacts transport facility design
because it limits the size of transport facilities to the EBTSs and increases the
demand on space at the centralized MSO.
DACS
BSC
MSC
EBTS
(radio link)
PCM
DS0s
SS7
Control
T1
EBTS
MSC co-located BSC configuration
T1s
1 per EBTS
Mobis
& VSELP
XCDR
CP
To each site
MSC
EBTS
(radio link)
PCM
SS7
Control
T1s
EBTS
MSC remote located BSC configuration
To site
DACS
DACS
BSC
T1s
CP
CP
T1s,
DS3s,
DS4s,
SONET,
ATM, ...
Mobis
Control
VSELP
RLP
T1s
T1
DACS
XCDR
XCDR
SS7
Control
BSC
Radio Link
(voice & control)