Tuesday, July 9, 2013

Abbreviations used in Telecommunication Industry

Here I have listed few Abbreviations that I came across during my training. 
ANC - Antenna Network Combiner
ARFCN - Absolute Radio Frequency Channel Number
BBH - Base Band Hopping
BCC - Base Station Color Code
BCCH - Broadcast Common Control Channel
BOI - Board of Investment
BSC - Base Station Controllers
BSIC - Base Station Identification Code
BSS - Base Station Substation
BTS - Base Transceiver Stations
CDR - Caller Detail Record
C/I - carrier over interfere
COW- Cell On Vehicle
CSR - Call Success Rate
DC- Dual Carrier
EIRP - Effective Isotropically Radiated Power
ETACS - Extended Total Access Communication System
FSL - Free Space Loss
GoS - Grade of Service
GPS - Global Positioning System
GSM - Global System for Mobile Communication
HLR - Home Location Registry
HO - Handover
HSN - Hopping Sequence Number
HSPA- High Speed Packet Access
IDD - International Direct Dialing
IDU - In Door Unit
IF - Intermediate Frequency
IN - Intelligent Network
IP- Internet Protocol
KPI - Key Performance Indicators
LA - Local Authority
LIU - Line Interface Unit
LTE - Long Term Evolution
MAI - Mobile Allocation Index
MAIO - Mobile Allocation Index Offset
MGW - Media Gateway
MIC - Milicom International Cellular
MIMO- Multiple-Input and Multiple-Output
MS - Mobile Station
MSC - Mobile Switching Centre
MW - Microwave
NAITA - National Apprentice & Industrial Training Authority
NCC - Network Color Code
NGN - Next Generation Network
NOC - Network Operational Centre
NPO - Network Performance Optimizer
NSS - Network Subsystem
ODU - Out Door Unit
OMCCS - Operation and Maintenance Centre Circuit Switching
OMCP - Operation and Maintenance Control Processor
OMCR - Operation and Maintenances Centre – Radio
PAT - Preliminary Acceptance Test
PDH - Plesiochronus Digital Hierarchy
PRN- Provide Roaming Number
QoS - Quality of Service
RAN - Radio Access Network
RCF - Radio Control Function
RCP - Radio Switching Point
RFH - Radio Frequency Hopping
RNE - Radio Network Engineers
RNP - Radio Network Planning
Rx - Receive
SAR - Site Acquisition Request
SDCCH - Standard Dedicated Control Channel
SDH - Synchronous Digital Hierarchy
SFH - Slow Frequency Hopping
SMSC - Short Message Service Center
SRI- Send Routing Information
SSP - Service Switching Point
SSW - Gigabit Ethernet Switch
SUM - Station Unit Module
TACS - Total Access Communication System
TC – Transcoder
TCH – Traffic/Voice Channel
TDM - Time Division Multiplexing
TIMSI- Temporary Mobile Subscriber Identity
TRC - Telecommunications Regulatory Commission
TRE - Transceiver Equipment
TSS - Technical Site Survey
TTI- Transmission Time Interval
Tx - Transmit
UMTS- Universal Mobile Telecommunications System
VAS - Value Added Services
VLR - Visitor Location Registry
VoIP- Voice over IP
WCS - Wireless Call Server

Drive Test

Drive Test will ensure the network performance and it is directly related to the QoS of the network. Normally drive tests are conducted by Technical Officers (TO) under the guidance of an Optimization Engineer. In Drive Test we drive on a vehicle which is well equipped to measure network performance. Gathered data are recorded using a drive test tool and we can analyze them later. Reasons for doing a Drive Test:
  • For Network Optimization: changing antenna azimuths and tilts
  • To identify network performance of area
  • To troubleshoot customer complaints
  • To check network coverage
  • After a major change in the network E.g. After a parameter change in site 
  • To check signal levels After commissioning a new site
In addition to these occasions we sometimes conduct indoor drive tests in situations when there are issues inside a building. In such situations a person wearing drive test tool and other required equipment will walk inside the building where we need to collect data. Here we face the problem of receiving GPS location. At such scenarios first a reference GPS point is taken at a location of the building. Then a sketch of the floor plan of the building is drawn on the map of the drive test tool. Then the drive test tool is taken on a path inside the building area in a fixed speed. We should travel on a fixed and steady speed because otherwise recording may not have correct details of the recorded data.

Equipment and Tools used in a Drive Test

I got to know about two Drive Test Tools. They are Ericson ® TEMS and JDSU (Agilent). TEMS is for 2G and Agilent is for 3G. Tool will record the details to a “.log” file.  Equipments used:
  • A laptop computer with drive test tool installed in it
  • Two mobile phones which supports the tool (one in Dedicated mode and other one in Idle mode)
  • GPS module to track location
  • The license dongle for the authentication of the drive test tool
Two mobile phones, GPS module and license dongle are connected to the laptop. We can upload the existing site file to the tool and according to the location of GPS, data will be recorded. When the record is done we can analyze the recorded data later.