INTRODUCTION

LM Ericsson is the worlds leading telecommunications equipment manufacturer. Around 40% of the

world network is controlled by LM Ericsson. It provides mobile systems solutions to network operators.

Its systems offerings include radio base stations, base station and radio network controllers, mobile

switching centers and service application nodes. Its end-to-end solutions offer operators a network

migration to 3G.

Being an electrical engineer, I was very happy as I got chance to do an internship from LM Ericsson. It

has a very nice working environment which is really important. All the employees are very sincere and

friendly to their work and colleagues. I tried heart and soul to enrich myself with technical knowledge

and corporate behavior , as well as ethics for the improvement of my country and my future. The things

which I learned here, are very important for an engineer .

Ericsson provides mobile telecommunications systems that incorporate any of the major second-

generation (2G) (global system for mobile communications (GSM), time division multiple access (TDMA),

code division multiple access (CDMA), 2.5G (General Packet Radio Service (GPRS), 2.75G (Enhanced Data

Rates for GSM Evolution (EDGE), and 3G wideband code division multiple access (W-CDMA), High-Speed

Downlink Packet Access (HSDPA), Evolved HSPA (HSPA+, I-HSPA), Evcode division multiple access (third

generation cellular/radio technology) (CDMA2000), time division synchronous code division multiple

access (TD-SCDMA)) mobile technology standards. It is able to offer tailored solutions to a network

operator, regardless of the existing network standard used. Ericsson is actively involved in the

development of standards for the Long-Term Evolution (LTE) of 3G. Through network operators Ericsson

offers service to over two billion customers worldwide.

Fig: GSM Architecture

MINI-LINK TN

MINI-LINK TN is a unique microwave transmission node, handling single hops and access sites as well as

advanced hub sites for large networks, optimized for traffic aggregation and capacity savings.

A terminal is one side of a microwave radio link hop, between two geographical locations. The terminal consists of an indoor part and an outdoor part.The indoor part comprises a Traffic Unit (TRU), Modem Unit (MMU), Access Module Magazine (AMM) and a fan unit. The outdoor part comprises a Radio Unit (RAU) with antenna. A radio cable connectsthe RAU and the MMU. Apart from the main units, the system offers a number of well-adapted auxiliary units and accessories, both hardware and software. Refer to the Product Catalog for more information.

The indoor units of a terminal are briefly described below.

Modem Unit (MMU): The MMU is the indoor interface with the radio unit and contains a modulator/demodulator. One MMU per radio unit is required. Traffic Unit (TRU): The TRU generates and terminates the STM-1/OC-3 traffic signal. It also contains a protection switching function used for protected terminal configurations. At least one TRU per terminal is required. Access Module Magazine (AMM): The AMM houses the MMU(s) and TRU(s) and provides electrical interconnection through its backplane. It fits in 19" racks and cabinets, as well as in ETSI and BYB cabinets. One or two terminals can be integrated into one common AMM. Fan Unit: A fan unit is always fitted on top of the AMM to guarantee sufficient cooling. The cooling air enters at the front of the AMM, flows between the units and out through openings at the back of the magazine on both sides of the backplane.

The outdoor units of a terminal are briefly described below.

Radio Unit (RAU) The RAU generates and receives the RF signal and converts it to/from the signal format used in the radio cable. Antenna The compact antenna combines high performance with minimum outdoor visibility. The antenna is normally installed integrated with the antenna but a separate installation is also possible. Radio Cable The radio cable, which connects the RAU to the MMU, is a single coaxial cable carrying full duplex traffic, DC supply voltage and service traffic as well as operation and maintenance data. Power Splitter The power splitter is used in 1+1 systems connecting two radio units to one antenna. The power splitter is available in a symmetrical and in an asymmetrical version. An integrated power splitter is also available.

PURPOSE :

The primary target of the internship was to upgrade the software of RAU’s and MMU’s of customer

sites. Overall I upgraded approximately 2000 nodes. Rest were upgraded by FME and NOC as remotely

we cannot upgrade all the nodes due to fading of signals for many reasons.

It is required to upgrade the RAU and MMU software for making it compatible with the continuously

upgraded network. The upgradation can be done remotely as well as locally. The upgradation procedure

is shortly shown below.

Step 1> Select one Traffic Node and follow the below displayed procedure step by

step.

Step 2 > Check existing SW Information and Release version from ‘Inventory’ option.

Step 3 > Select Tools Software Upgrade

> Below screen will be appeared. Select ‘Upgrade of Modules’.

Step 4 > Select ‘Local Server’ option from FTP and provide server address (for example 10.10.1.10) .

Browse and select New Release RAU SW version from server.

Select ‘New Release’ version Tick ‘Upgrade’ field Select ‘Apply’ button.

Step 5 > ‘Settings’ window will be appeared. Select ‘Immediate’ and ‘Automatic’ then press ‘Apply’.

Select ‘Start Upgrade’.

Step 6 > After completion of upgrade, select ‘Activate’ and the ‘Confirm’

Step 7 > In same way browse corresponding new SBL Release version and press ‘Apply’ for next.

Step 8 > Select below mentioned options

> After completion of SBL up-gradation go for activation accordingly. Please note, SBL SW activation is

traffic disturbing.

> Finally check overall SW up-gradation status from Inventory

At the last part of my internship I was enrolled to Field Maintenance Engineering . I worked at the

Power & Infrastructure sector for about a month and learned about the power management and power

supplies for the RBS’s. I was able to see the troubleshooting of field team . I also went to several sites of

our customer inside Dhaka city including DHAKA 1 (MSC) and DHAKA 2(MSC) and have gathered

knowledge about GSM antenna, Microwave antenna, feeder cable, jumper cable , power batteries and

inverters used for sites . The FM members of the sites were very helpful who gave me several

knowledge about Mobile Switching Centre. I was physically able to see the 2p,6p,20p TN magazine,

IGW, VLR,HLR , MUX , OSS server, GMSC, DXU , backbone networks, MPBN etc used for a telecom

network.

Fig: GSM antenna of an RBS Fig: Feeder cable

Fig: Jumper inlet to node Fig: Connecting to a node locally

Fig : Patched Modems of an RBS Fig: AVR for RBS

Fig: Genset of an RBS Fig: Battery used for an RBS

I worked with the performance and reporting team, where the preventive maintenance(PM), trouble

ticketing(TT), change request (CR) etc are handled for customer sites. There are two type of PM. Active

PM and passive PM. Active PM includes the health check up of telecom and transmission equipments.

Passive PM includes infrastructural check up .Ericsson takes all preventive steps to maintain the sites

including prevention of power outage, security of the sites,

DWDM Other Equipments

Actura ® 48701

Emerson Rectifier

3X 250A BFU

Emerson EB4 Battery,

48V/600Ah

Cabinet Sizes:

600x400x1800mm

Cabinet sizes:

400x600x1850mm

3X 250A BFU

Emerson EB4

Battery, 48V/600Ah

Cabinet Sizes:

600x400x1800mm

DWDM

3X 250A BFU

3.2 KW Rectifier Module

3.2 KW Rectifier Module

200A DU

200A DU

200A DU

SCU

Fig: Single Line Diagram for MUX power connection

CONCLUSION

I would like to thank some people for this excellent experience from LM Ericsson. For their co-operation

I was able to gather a lot of knowledge about telecommunications engineering.

Mohammad Abu Bakar Shibly.

Maynul Akter Md. Kayes

Imtiaz Shazzad

ASM Showaibur Rahman

Abdul Hai Mollah

Nasiruddin Biswas

Syed Mohammad Ali

Overall Ericsson takes very good care of their customer sites with their sincere employees. The

equipments supplied to their customers are worldclass and Ericsson maintain these equipments with

proper managed services. Each equipments are so well maintained that even a minor alarm is

prevented. So therefore, Ericsson always keeps their customers upgraded with their latest equipment

and software release. Though it is a matter of cost, but Ericsson provides its customer the best quality

service within a reasonable price. Technical enrichment is very necessary for any company to do good

business and provide best service.