User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
4 System Function
4-9
MS
BTS
BSC
(2) Abis-BTS Setup
(3) Abis Connect
(4) Abis Connect Ack
(5) Abis-BTS Setup Ack
(1) Supplemental Channel Request Message
(6) Abis Burst Request
(7) Abis Burst Response
(8) Abis Burst Commit
(9) Extended
Supplemental Channel Assignment Message
Figure 4-7
Reverse SCH establishment procedure
1) If the packet data call is established, MS may send “Supplemental Channel
Request Message” to BSC for establishing SCH channel.
2) BSC sends “Abis-BTS setup” to BTS, to request BTS to allocate radio resource
for the call.
3) After BTS establishes the channel, it sends “Abis-connect” to BSC.
4) BSC responds with “Abis-connect ack” to BTS.
5) After BTS establishes all of the channels, it sends “Abis-BTS setup Ack” to BSC,
indicating the completion of terrestrial circuit establishment.
6) BSC sends “Abis-Burst Request” to BTS to activate BTS.
7) BSC responds “Abis-Burst Response” message to BTS.
8) BSC sends “Abis-Burst Commit” to BTS, and BTS starts to transmit SCH.
9) BSC sends “Extended Supplemental Channel Assignment Message” and
assigns SCH channel for MS, so that the packet data service can be
transmitted at high speed in SCH channel.
4.3 Signaling Processing
BTS signaling processing serves two purposes:
l
Implement interconnection of MS and BSS/CN on the air interface layer.
l
Perform part of radio resource management function under the control of BSC.
Specifically, BTS signaling processing performs the following functions: signaling
processing on Abis physical layer and transmission layer, channel resource
management, Abis traffic link management, BTS logic operation & maintenanc e