7/26/2019 Signalling in GPRS
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GPRS data structure
MS
BSC (PCU
SGSN
RLC =Radio Link CoLLC =Logical Link CFr.Rel. =Frame Rela
RLC!M"C#locks
LLC Fram
B$SMulti%le MS cans&are one $C' #ut one MStransmits at a
time.$BF ($em%orar Block Flo)
= c&annels *rom one $R+as de,ned # MS multislot class
Contains cell id
Contains $F-
LL! frame (LL!"#DU
mean$ t%e data &art of
DL'UITD)T) or UL'Uin +B"interfa,e.
Max.len*t% of a LL! fram
$BFs eto alloto car
MS
+#S I# Ba,bone
L1
L2
I#
+T#
L1bi$
Fr.el.
BSS+#
SD!#
LL! UD#
S+S
ela
Gn
Internet
L1
L2
I#
T!#/UD#
)##
Gi
LL!
SD!#
I#
T!#/UD#
)##
L!
M)!
+SM F
MS
L!
M)!
+SM F
BSS+#
Fr.el.
L1bi$
BSS
!i&%erin* and reliable lin
UmGb
!om&re$$ion3 $e*mentation
FI45D 6ST
Ma LLC = /012#tes
(PCU)
Fast error correction
"R3 4rror correction ("C5)B%
F%
LLC layer
RLC/MAC layer
Physical layer
I#(or'at"o# ("el d FCS
Nor'al -ur.t Nor'al -ur.t Nor'al -ur.t Nor'al -ur.t
I#(o ("eldB% BCSRLCblocks
LLC frame
Primaryblock
Followingblock
I #(o ( "e ld BCS I#(o (" el dB% BCS
F% = Fra'e %eaderFCS= Fra'e C/eck Se>ue#ceB% = Block
%eaderBCS= Block C/eck Se>ue#ce
?/e# S+CC% cod"#$ ". u.ed6 BCS corre.po#d. to t/e F"re code!
