logical channels & multi-frame structures

7/24/2019 Logical Channels & Multi-Frame Structures

1/20

Logical Channels and Multiframe Structures

Khizar Mahmood Zia & Safdar Yaseen


2/20

LOGICAL CHANNELS


3/20

LOGICAL CHANNELS


4/20

CONTROL CHANNELS

Broadcast Channel (BCCH):

Transmitted by the BTS to the MS. This channe carries system!arameters needed to identi"y the net#or$% synchroni&e timeand "re'(ency #ith the net#or$% and )ain access to the

net#or$. Common Control Channels (CCCH):

*sed "or si)nain) bet#een the BTS and the MS and to re'(estand )rant access to the net#or$.

edicated Control Channels (CCH):*sed "or dedicated comm(nication s(ch as ca set(!% SMS%Location Area *!dated


5/20


6/20

BROA+CAST CONTROL CHANNELS

Broadcast Control Channels (BCCH):

Broadcast Contro Channe sends net#or$,s!eci"ic in"ormations(ch as radio reso(rce mana)ement and contro messa)es%Location Area Code etc.

!CCH :

Mobie corrects the "re'(ency o" its interna time base byreadin) this o)ica channe.

SCH :

Carries the in"ormation "or mobie to synchroni&e to the T+MA"rame str(ct(re - $no# the timin) o" the Indiid(a timesots./rame N(mber - BSIC 0Base Station Identity Code1.


7/20


8/20

COMMON CONTROL CHANNELS

"#CH: Transmitted by the MS #hen it #ishes to )ain access tothe system$

%CH: Transmitted by the BTS #hen it #ishes to contact as!eci"ic mobie.

#CH: Transmitted by BTS to assi)n a dedicated reso(rce toMS s(ch as S+CCH

CBCH: Trans"er Messa)e #ith in a ce to a mobies.


9/20


10/20

+E+ICATE+ CONTROL CHANNELS

Stand #lone edicated Control Channels (SCCH):

*sed d(rin) Ca Set(!% Location Area *!date% SMS

Slo' #ssociated Control Channel (S#CCH)$

Coneys !o#er contro and timin) in"ormation in the do#nin$direction 0to#ards the MS1 and Receie Si)na Stren)th Indicator0RSSI1% and in$ '(aity re!orts in the (!in$ direction.

!ast #ssociated Control Channel (!#CCH)$

The /ACCH is transmitted instead o" a TCH. The /ACCH 22steas3

the TCH b(rst and inserts its o#n in"ormation. The /ACCH is (sedto carry o(t (ser a(thentication% handoers and immediateassi)nment.


11/20

TRA//IC CHANNELS


12/20


13/20

CHANNEL COMBINATIONS

/( Rate Tra""ic Channe Combination 4 TCH56/ACCH 7 SACCH

Broadcast Channe Combination 4 BCCH 7 CCCH

+edicated Channe Combination 4 S+CCH5 7 SACCH5

Combined Channe Combination 4 BCCH7CCCH7S+CCH87SACCH8


14/20

M*LTI,/RAME STR*CT*RES


15/20

TRA//IC CHANNEL M*LTI/RAME


16/20

CONTROL CHANNEL M*LTI/RAME


17/20

BCCH6CCCH M*LTI/RAME


18/20

+CCH65 M*LTI/RAME


19/20

COMBINE+ M*LTI/RAME


20/20

S*9ER /RAMES - H:9ER /RAMES

logical channels & multi-frame structures

Documents