Zte ZXG10 OB06, Technical Manual

Page: 75 / 117

Chapter 4 - System Functions
Confidential and Proprietary Information of ZTE CORPORATION 61
When the TRX receives the MS random access request, it sends the
channel request message to the BSC.
The CHAN RQD message contains the Request Reference parameter (MS-
selected random number, low-order bit of the TDMA frame number) and
access burst pulse sequence measurement delay.
Immediate Assignment
The procedure of immediate assignment is shown in Figure 49.
F
I G U R E
4 9 I
M M E D I A T E
A
S S I G M E N T
MS LAPDm FURRM PAGCHM LAPD
BSC OAMM
(RR) im m ass
PAG_ DATA _REQ
(PAG IM M ASS)
(IM M ASS CM D)
DL_DATA _IND (IM M ASS CM D)
The immediate assignment message is transmitted in the downlink CCCH
(AGCH) channel.
The immediate assignment message that is from the network side may be
(RR) IMMEDIATE ASSIGNMENT, (RR) IMMEDIATE ASSIGNMENT
EXTENDED or (RR) IMMEDIATE ASSIGNMENT REJECT. On the Abis
interface, it is contained in the IMM ASS CMD message, which contains
complete the “immediate assignment” message and where the “paging
mode” unit is set as “unchanged”. When this message is received, the
FURRM sends it to the PAGCHMan sub-module of the PAGCHM module.
That sub-module places the message in the buffer. When the trigger is
received from the ISR, the PAGCHDaemon sub-module of the PAGCHM
module forms the messages in the waiting queue into the (RR) IMMEDIATE
ASSIGNMENT EXTENDED or (RR) IMMEDIATE ASSIGNMENT REJECT
message and sends to the CHP. Before the send, the OB06 changes the
“paging mode”
If no channel can be assigned, the BSC sends the (RR) IMMEDIATE
ASSIGNMENT REJECT on the same CCCH timeslot where the channel
request message is received.
If the downlink CCCH is overloaded, the FURRM sends the DELETE IND
message to the BSC, notifying that an IMM ASS CMD command is deleted.