Specifications

Base Site Controller
iDEN® System
2-16 68P81095E55-E August 08, 2000
Home Agent The MDG stores a provisioned MSs Internet Protocol (IP) address in a database.
This IP address is used to identify, permission and route data packets from the
internet to the MS during Packet Data operation. The Home Agent identifies an
MDG as the point-of-presence on the Internet that accepts data packets addressed to
IPs in the Home Agent database.
A home agent MDG can a communicate with remote MDGs and temporarily transfer
the logical addressing to the remote MDG (foreign agent) when the MS is roaming in
another system. The Home Agent will transfer a roaming MSs IP address to the
remote MDG so the remote MDG will accept packets for the MS. The Home Agent
then re-routes packet data information to the remote MDG (Foreign Agent) as
required.
Foreign Agent During roaming, an MS will register and attempt to authenticate in a remote system.
For Packet Data operation, the remote system will contact the MSs home system
MDG (Home Agent) and obtain authentication, identification, services and
permissions information. If allowed, the MDG will receive the visiting MSs IP
address and allocate resources to service the MS. This enables the remote (visited)
MDG to accept packets routed to it by the Home Agent MDG.
Base Site Controller
Physical Components
A Base Site Controller (BSC) may be linked to one or more EBTS sites. The BSC
manages Interconnect Call Processing between EBTS sites and other network
devices. The BSC (Figure 2-9) is divided by function into to physical shelves in a
rack or it may be divided into individual racks. The major BSC shelves are:
• Base Site Controller - Control Processor (BSC-CP)
• Base Site Controller - Transcoder (BSC-XCDR)
Base Site
Controller - Control
Processor
The Base Site Controller - Control Processor (BSC-CP) contains the memory and
logic circuits to administer and monitor the routing of Interconnect Calls. The BSC-
CP manages the general call signalling and voice paths of the BSC-XCDR. One side
of the BSC-CP connects to the Mobile Switching Center with SS7 signalling and the
Operations and Maintenance Center with X.25 protocol. The other side connects to
the EBTS through the DACS with modified A-bis interface (Mobis) signalling and
alarm and maintenance data with X.25 protocol. The BSC-CP consists of:
• MegaStream Interfaces — to physically connect external paths (T1 spans)
• Cross Connect Switch — to dynamically connect control paths
• Generic Processors — for overall control and monitoring of BSC operation
Base Site
Controller -
Transcoder
The BSC Transcoder (BSC-XCDR) converts the voice packets used on the radio link
to the Pulse Code Modulation (PCM) used by local and interconnected Public Switch
Telephone Networks (PSTNs). The BSC-XCDR consists of:
• MegaStream Interfaces — to physically connect external paths (T1 spans)
• Cross Connect Switch — to physically connect traffic paths
• Generic Processors — to route traffic packets internally to the XCDR
• Transcoders — to convert between radio link packets and PCM