1. Prepared by Abdulrahman Fady

2.  L3 Messages is the messages transferred
between MS and Network (BSC or MSC ) to
control the MS behavior in idle mode and in
dedicated mode as well as tell MS when to do
Location update
 L3 Messages are UL and DL and conveyed on
Control channels
◦ BCCH
◦ PCH
◦ SDCCH
◦ SACCH
◦ FACCH

4.  What are system Information Messages
◦ Downlink messages
◦ sent on BCCH channel or SACCH channel
◦ Used to inform MS by all the needed information to
enable it to do its operations in normal way
◦ SI messages transmitted periodically from BTS and MS
reads them every 30 sec for serving cell and every 5
minutes for six strongest cells
◦ There are a lot of SI types e.g. SI type 1, SI type 2

5.  Direction : DL
 Channel : BCCH
 Contents
◦ BCCH Frequency
◦ Available frequencies
◦ RACH Control
parameters as MAXRET
◦ Cell Barring
◦ Emergency

6.  Direction : DL
 Channel : BCCH
 Contents
◦ BCCH frequency
◦ MAXRET
◦ Call re-establishment
control
◦ NCC permitted range
◦ Cell Barring

7.  Direction : DL
 Channel : BCCH
 Contents
 PLMN ID (MCC & MNC)
 Cell ID
 LAC
 MFRMS
 AGBLK
 Mapping Method
 ATT
 T3212
 RL_timeout
 Selection Parameters
 ACCMIN
 MAX-TX-PWR-UL
 CRH
 Cell reselection
 CRO
 PT
 TO
 Half rate support
 SI scheduling

9.  Direction : DL
 Channel : BCCH
 Contents
 PLMN ID (MCC & MNC)
 Cell ID
 LAC
 Cell Selection Parameters
 Cell Reselection Parameters

10.  Direction : DL
 Channel : BCCH
 Contents
 Other Band BA list

11.  Direction : DL
 Channel : BCCH
 Contents
 Same Band BA list

12.  Direction : DL
 Channel : BCCH
 Contents
 GPRS Information
 EGPRS Supported
 Power control
 Network Mode

13.  Direction : DL
 Channel : SACCH
 Contents
 GPRS Information
 Cell ID
 LAC
 PLMN ID
 RL timeout
 DTX info
 Band

14.  Direction : DL
 Channel : SACCH
 Contents
 BA list

15.  Direction : DL
 Channel : SACCH
 Contents
 Part from Active BA
list

16.  Direction : DL
 Channel : SACCH
 Contents
 Part from Active BA
list
 Multi band reporting

17.  Immediate Assignment
◦ SDCCH assignment during Call Setup
 Measurement Report
◦ MS should report 6 strongest neighbors cells to BSC
 Handover Command
◦ BSC instruct the MS to do HO to certain Cell
 Handover Access
◦ MS starts HO process
 Handover Complete
◦ Message sent after HO completed Successfully

18.  Direction : DL
 Channel : AGCH
 Contents
 Inform MS about
SDCCH that will be
used in call Setup

19.  Direction : UL
 Channel : SACCH
 Contents
 Six strongest
neighbors

20.  Direction : DL
 Channel : SACCH
 Contents
 Instruct the MS to
handover to a certain
cell by sending its
information
 BCCH
 BSIC
 MAIO /HSN

21.  Direction : UL
 Channel : FACCH
 Contents
 MS tries to access
the new cell using
this message

22.  Direction : UL
 Channel : FACCH
 Contents
 MS inform the
network that the HO
has been completed
successfully