User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
4 System Function
4-6
9) BSC sends “Abis-Connect Ack” to BTS in response to “Abis-Connect”
message.
10) BTS completes resource allocation, and sends “Abis-BTS Setup Ack” message
to BSC.
11) BSC sends “Abis-IS2000 FCH Fwd” message to BTS, to order BTS to send null
frame to MS.
12) After receiving “Abis-IS2000 FCH Fwd” message, BTS sends null frame to BSC
via “Abis-IS2000 FCH Rvs” message, and performs Abis link delay adjustment.
13) BSC sends channel assignment message to BTS via “Abis-PCH Msg Transfer”
message. BTS forwards the message to MS on paging channel.
14) MS begins to send traffic channel preamble on the assigned reverse traffic
channel. After capturing the preamble, BTS sends traffic channel preamble to
BSC via “Abis-IS2000 FCH Rvs” message.
15) After BSC receives the traffic channel preamble sent from MS, it sends “Base
Ack” order to BTS via “Abis-IS2000 FCH Fwd” message. BTS forwards the
order to MS over the forward traffic channel.
16) After MS receives “Base Ack” order, it stops sending traffic channel preamble
and starts sending data frame.
17) After MS receives “Base Ack” order, it sends “MS Ack” order to BTS. BTS
forwards the order to BSC via “Abis-IS2000 FCH Rvs” message.
18) After BSC receives “MS Ack” order, it sends service connection message to
BTS via “Abis-IS2000 FCH Fwd” message. BTS forwards the message to MS,
and then MS starts to handle the service according to the designated service
configuration.
19) To respond to service connection message, MS sends service connection
complete message.
20) After BSC receives the service connection complete message, it sends
assignment complete message to MSC.
4.2.2 Data Service Call Procedure
I. MS-originated data service
MS-originated data service procedure is shown in Figure 4-6.