ALCATEL LUCENT BTS

Prepared By: SAYED QAISAR SHAH BS TELECOM,CWNA,CCNA.

BTS Role in GSM Network

The BTS provides two-way radio communication between the PSTN and Mobile Station (Mobile Set) located in a single GSM cell. It also provides a similar link between the mobile station and the rest of the networks. The BTS provides on interface for the digital baseband signals used by the land based networks and the GSM radio signals used by mobile station.

Logical position of BTS in BSS

Functional Architecture of BTS

BTS Functions

As the principal interface between the PSTN and Mobile Stations, the BTS performs four primary functions.

Transmission function: which manage the transfer of traffic and control

data between the BTS and BSC. Telecommunication functions: which manage the transfer of

traffic and control data between the BTS and Mobile Station. O&M function: which supervise the operation of the BTS. Support function: which provides a logical and physical

environment in which the BTS functions can be realized.

Communication between the transmission, telecommunication, and O&M functions is managed according to the OSI model. The BTS functions are concerned with layer 1 (Physical), Layer 2 (Data Link), and Layer 3 (Network) of this model.

Transmission Functions

To minimize operating costs, all data passed between the BTS and BSC in Time division multiplexed onto a single physical interface. This is the Abis Interface, which carries all the data sent between the BSC and BTS. Logical links between the BSC and BTS handles the following information:

Signaling data used for control purposes O&M data for the BTS transmission module O&M data for the BTS entities User data in the form of speech and data traffic.

Transmission Functions

Abis Interface:

For BTS and BSC multiplexing equipment is normally connected using dedicated cabling. Other method of Abis Interface connection can be used for BTS, where the installation of the dedicated cabling in not possible. In this case, control of the transmission medium is in the hands of third party.

Microwave Link (used where line of sight radio path is available. Leased Line (Copper Cable or Fiber Optic used where the distance between the BSC and BTS is too great for microwave).

Satellite Link (Used where Previous two methods are not possible

Telecommunication Function

There are two primary telecommunication functions:

Baseband Functions:

Based band functions modulate and encode traffic and signaling data from the BSC according to GSM recommendations. This data is then sent to the Mobile Stations using the RF function. Traffic and signaling received from the Mobile Stations is demodulated and decoded to recover the baseband data.

Telecommunication Function

RF Function:

RF functions enable traffic and signaling to be sent and received over the Air Interface as a radio signal. A special link layer protocol ensures the reliable transfer of signaling data over the Air Interface.

For antenna Diversity, the telecommunication function uplink path is duplicated. The duplicated functions intend from the antennas, through the RF functions.

O&M Functions

O&M functions monitor and control the correct operation of the BTS and its external interfaces. These function are shared between the BTS and BSC. The BSC provides overall control.

The O&M function use Layer 2 links for BTS internal communications. A terminal connected via an MMI is used for local operator control of the BTS.

There are three categorized of O&M function: Configuration Management Fault Management External Alarm Handling.

The O&M function also control the operation of the RF self-tests and manage the actions required by the BTS recovery Strategy

Support Function

The support function provides a number of services relevant to the internal working of the BTS are:

Internal Power Supplies. Internal Temperature Control. Master Frequency. Clock generation and distribution. External alarm collection. Internal self tests.

INTRODUCTION OFALCATEL LUCENTBTS

BTS Circuit Breakers (BCB)

Network Interface Card

External Alarm Circuit Board (EACB)

Shelf # 5

Shelf # 4

Shelf # 3

Shelf # 2

Shelf # 1

Combiners

TRE

SUMA Card

Port Address:Formula:

16n + 1 ( n = shelf number )

This formula is for the first port of each shelf. For remaining three ports add 3 in the above formula for each port.

External Alarm Circuit Board (EACB) Abis

PatchingBTS Circuit Breakers

(BCB)Clock Port

BTS Circuit Breakers

(BCB)

External Alarm Circuit Board

(EACB)

Abis Patching

Clock Port

Transmitter Connector

Antenna Connector

Lock Fastener

Module Extractor

Receiver Connector

Equipment Label

Bridge

Lock Fastener

Transmitter Connector

Module Extractor

Receiver Connector

Antenna Connector

Equipment Label

Bridge

Lock Fastener

Transmitter Connector Module

Extractor

Equipment Label

ON/OFF Switch

USB Test Connector

Receiver Connector

LEDs

Abis ½ Connector

Lock Fastener

Equipment Label

BTS ConnectionArea Connector

BTS Terminal Connector

Test Connector

USB Connector

LEDs

Remote Inventory

Cable(RI Cable)

Remote Inventory Cable

(RI Cable)

Cabinet Cooling Fan

THANK YOU