LM Ericsson is a leading telecommunications equipment manufacturer, providing mobile systems solutions and end-to-end network solutions to operators. The author completed an internship at Ericsson where they learned about technical and corporate skills while helping to upgrade the software on 2000 network nodes in Bangladesh. They gained experience in fields maintenance and saw first-hand how Ericsson maintains high quality networks for its customers.

2. 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

3. 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.

4. 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.

5. 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.

6. 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.

7. Step 3 > Select Tools  Software Upgrade
> Below screen will be appeared. Select ‘Upgrade of Modules’.

8. 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.

9. 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’

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

12. Step 8 > Select below mentioned options

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

14. > 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.

15. 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

16. 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

17. 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.