BSS Description B10 (3FL10473A-ed 2)
BSS Description B10 (3FL10473A-ed 2)
BSS Description B10 (3FL10473A-ed 2)
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1. Evolium <strong>BSS</strong> Introduction<br />
Situation and Functions<br />
ALCATEL <strong>BSS</strong> <strong>Description</strong> 14<br />
<strong>BSS</strong> functions (1): CALL SETUP<br />
The <strong>BSS</strong> provides radio coverage (signalling and traffic channels) between<br />
Mobiles and the NSS.<br />
MOBILITY MANAGEMENT<br />
Location updating<br />
SUPPLEMENTARY SERVICES<br />
Short Message Service<br />
USER TRAFFIC<br />
Speech<br />
Data<br />
EVOLIUM<br />
ALCATEL <strong>BSS</strong> <strong>Description</strong><br />
All Rights Reserv<strong>ed</strong> © Alcatel-Lucent 2008<br />
Call set up is requir<strong>ed</strong> to establish communication between an MS and the NSS. The NSS is responsible for<br />
establishing the connection with the correspondent. Different types of calls require different<br />
teleservices. These teleservices are defin<strong>ed</strong> in the GSM specifications. The type of teleservice and<br />
bearer service to be us<strong>ed</strong> is negotiat<strong>ed</strong> before the normal assignment proc<strong>ed</strong>ure.<br />
Mobility Management : These calls, e.g. location update, are us<strong>ed</strong> by the system to gather MS<br />
information. The exchanges are protocol messages only; therefore, only a signaling channel is us<strong>ed</strong>.<br />
Supplementary Services : These calls, e.g. SMS and SS calls, pass small amounts of information.<br />
Therefore, only a signaling channel is us<strong>ed</strong>.<br />
User Traffic : These calls, e.g. speech or data calls to a correspondent, can pass large amounts of<br />
information. Therefore they require greater bandwidth than a signaling channel. These calls use<br />
traffic channels.<br />
The channels us<strong>ed</strong> for calls are the SDCCH for signaling and the TCH for user traffic. These channels are<br />
associat<strong>ed</strong> with FACCH/SACCH. An SDCCH is always assign<strong>ed</strong> for call set up, even if a TCH is later<br />
requir<strong>ed</strong> for the call.<br />
The role of the <strong>BSS</strong> in call set up is to assign the correct channel for the call, and to provide and manage<br />
a communication path between the MS and the MSC.<br />
The phases involv<strong>ed</strong> in call set up:<br />
Radio and Link Establishment;<br />
Authentication and Ciphering;<br />
Normal assignment.<br />
All Rights Reserv<strong>ed</strong> © 2007, Alcatel-Lucent<br />
<strong>3FL10473A</strong>DAAWBZZA Edition 02<br />
EVOLIUM ALCATEL <strong>BSS</strong> <strong>Description</strong> Page 14