Specifications

Functions
Dispatch Call Processing
4-4 68P81095E55-E August 08, 2000
• Establish Radio Link
• Route digital voice packets
• Duplicate packets for group calls
Establish Radio
Link
The radio link is the on-air connection. The radio link is a coordinated effort
between the MS, the EBTS, MPS and the DAP. The EBTS/DAC/MPS complex
routes the call setup information to the DAP. The DAP queries the D-HLR and D-
VLR to determine service access, authentication, and service availability. The EBTS
establishes and maintains the radio link on the RF control channels. If the MSs
location indicates another EBTS has better radio link quality, the mobile re-connects
to the EBTSs without handover control overhead. The MS re-selects and connects
dynamically as required.
Route Digital Voice
Packets
Once the radio link is established, the EBTS discriminates between a Interconnect
call and a Dispatch call. The DAC will cross-connect dispatch voice packets to the
MPS. The MPS coordinates the movement of packets between the EBTSs and the
DAPs. The MPS re-routes calls to another EBTS if the MS reconnects. If more than
one called MS is involved (group call) the MPS routes the voice packet to the DAP
and Packet Duplicator to be copied. The copied packets are routed to the appropriate
EBTS as determined by the call type.
Packet Duplication For Dispatch group calls the VSELP voice packets are routed to the Packet
Duplicator where they are copied and applied to the appropriated link by the MPS.
The DAP controls call routing and coordinates the services. The MPS handles the
timing and routing of the voice packets.