Radio Frequency Engineering

WCDMA breathing effect and Coverage - Capacity trade off

2016-05-05T16:03:00.000+06:00

In WCDMA, the relation between coverage and capacity referred to as “breathing effect”. The load of WCDMA network has a greater effect on it's coverage. The load of WCDMA network impacts on own system in two ways, depending on which link (uplink and downlink) has been taken into account. For uplink as more user added to the network, higher interference or noise will be detected at the Node B end. This effect called rise over thermal. That’s why UE need to transmit at higher power to overcome this effect.

Rise Over Thermal (dB)

When the loading of the system increases the Ec/No degrades, but the RSCP remains constant. Degrading Ec/No is an indication of increased other cell interference which demands the increase of downlink traffic power. Power being a limited resource, the requirement of higher transmit power may not be available, thus the coverage not being met in loaded condition; this scenarios called “coverage and capacity trade-off” for the downlink in a WCDMA systems.

Coverage and Capacity Trade Off

GSM Radio Parameter Details and Score evaluation from Drive Test (DT) end

2015-12-05T17:39:00.002+06:00

Radio Parameters :

RxLev: Rxlevel represents received signal strength of GSM network. Rxlevel is an independent drive test (DT ) parameter. Value of Rxlevel generally expressed in dbm. Rxlevel ranges from -10 dBm to -120 dBm. Here , value of Rxlevel "-10dbm" represents strongest signal and "-120dbm" represents weakest signal. The acceptable values of Rxlevel in a commercial GSM network should be above -95 dbm (-10 dbm to -95dbm).

Geographical presentations of Rxlevel (Received signal level) in Laxmur- Noakhali Highway

RxQual: RxQual means for received signal quality. RxQual measured on the basis of BER. So,RxQual is a dependent parameter. RxQual ranges from 0 to 7. Here "0" represents the best quality signal and 7 represents the worst quality signal. The acceptable values of RxQual in a commercial GSM network is "0 to 5".

Geographical presentations of RxQual (Received Signal Quality) in Laxmur- Noakhali Highway

BER: BER means for bit error rate. Actually BER is a Ratio of the number of bit errors to the total number of transmitted bits in a certain period of observation. BER is inversely proportional to the Rxlevel and directly proportional to the interference level. The acceptable values of BER in a commercial GSM network should be bellow 6.4. Depending on BER values RxQual is measured. The relationship between BER and RxQual is given bellow:

Relationship between BER and RxQual

FER: FER means for Frame Erasure Rate. FER represents the percentage of a ratio (frames being dropped due to high number of bit errors by total number of transmitted frame) in a certain period of observation. GSM MOS value (Voice Quality indication) largely depends on FER value. FER is also a dependent parameter; the value of FER (Frame Erasure Rate) depends on BER ( Bit Error Rate).

SQI : SQI means for Speech Quality Index .SQI is a dependent parameter, the values of SQI depends on the BER, FER and Speech Codec. There are three types of Speech Codec in GSM, these are EFR ( Enhanced full rate 12.2 kbit/s), FR (Full rate 13.2 kbits/s), HR (Half rate 5.6 kbit/s). The value of SQI is updated every 0.5s and SQI values ranges from 0 to 30. Here, "0" represents worse quality speech and "30" represents best quality speech. The acceptable values of SQI in a commercial GSM network should be above 15.

C/I : C/I represents the ratio carrier-over-interference. The ratio between the signal strength of the current serving cell and the signal strength of unwanted (interference) signal components. The acceptable values of C/I in a commercial GSM network should be above 9dbm".

MS Power Control Level: MS power control level indicates the transmit power control scheduled by the base transceiver station (BTS). This parameter is valid only in dedicated mode. Generally it's ranges from 0 to 31.

DTX: DTX means for Discontinuous transmission. DTX is a mechanism which allows the radio transmitter to be switched off during speech pauses. This feature saves the power consumption of the Radio transmitter, which is important for User Equipment(UE) or Mobile station(MS) and it's also decreases the overall interference level on the radio channels affecting the capacity of the network.

TA: TA means for timing advance. TA represents the length of time takes to reach a signal from base station to the mobile station (MS). In GSM TA value changes after every 550 meters.TA values ranges from 0 to 63. That is a GSM cell can cover maximum (63 X 550) = 34.6 km

RLT Counter (Cur): RLT Counter(Cur) means Radio link timeout counter (current). This parameter defines the value of the radio link counter. RLT Counter(Cur) ranges of 0 – 64. When RLT counter (Cur) reaches zero it results in normal DROP Call.

RL Timeout Counter (MAX): This parameter defines the maximum value of the radio link counter. RLT Counter(MAX) range from 4 – 64 in step size of 4.

MS Behavior Modified: This window shows current settings for the mobile station, for example whether handover is disabled or not, multi band reporting enabled or not etc.

Different types of Voice quality measurement systems and score evaluation (GSM and WCDMA)

2015-11-19T16:33:00.002+06:00

There are different types of quality measurement system exist in telecommunication. For voice and video quality, we use different types of measurement policy. But few standards are common and ratified by the different regulatory body such as ITU, ETSI, AT & T etc. During the measurement or testing procedure, we use different types of algorithm for different measurement system or different testing purpose. But among them few standards are very popular and vastly used for assessing the voice and video quality. Generally we can classify the measurement system into two parts one is subjective evaluation and another is objective evaluation.

Different types of voice quality measurement systems are given bellow:

ITU-T recommendation for voice quality testing

MUSHRA (Multiple stimulated with hidden reference and anchor) , In MUSHRA we use "lossy audio compression algorithm". MUSHRA ratified by ITU-R BS 1534- 2 and ITU- R BS 1534-3. It's a subjective evaluation system.

PSQM (Perceptual speech quality measurement) is such a measurement system which allows automated and simulation based methodologies for rating both voice clarity and transmitted voice quality. This system ratified by ITU-T P 861. In PSQM, we use a psychoacoustical mathematical modeling algorithm to analyze the pre and post transmitted voice signals. ITU-T already replaced PSQM(ITU-T P861) by PESQ (ITU-T P862).

PESQ (Perceptual evaluation of speech quality) was developed as a model of subjective tests as per industry standard which will be widely used in Telecommunication system. It was standardized as ITU-T recommendation P.862 (02/01). Latter PESQ scores mapped into MOS score which was standardized as ITU-T P862.1. The scoring values of PESQ SQI MOS(speech quality index mean opinion score) ranges from 1 to 5 inwhich 1 means worse and 5 means best. The final score of PESQ SQI MOS is the arithmetic mean of all the tested scored.

The thematic presentation of PESQ SQI MOS is given bellow:

Geographical distribution of PESQ SQI MOS Score from DT log

POLQA (Perceptual Objective Listening Quality Assessment) is the most recent ratified voice quality assessment system and best suited for wide band audio signal measurement. POLQA covers a model to predict a speech quality or alternatively we can treat it as digital speech signal analysis and rating procedure. POLQA was developed as per ITU- T 863 recommendation. It's the most widely implemented voice assessment system and excellent successor of PESQ (P8621). As like PESQ values POLQA scores ranges from 1 to 4.5. POLQA score evolution almost like PESQ. 1 means worse and the value equivalent to 4 or above 4 is excellent.

POLQA Reference vs Degraded audio signal

WCDMA Network’s Physical or Antenna Parameter Optimization Procedure and Purpose

2015-10-19T00:45:00.000+06:00

Before tuning physical parameter or antenna parameter an engineer should have clear understanding on flowing issue:

A) Basic principle of Antenna.

B) Antenna selection procedure for different radio environment.

C) Antennacharacteristics and Classification.

An antenna is a passive device which can transmit and receive radio waves. When antenna transmits its convert RF current into electromagnetic (EM) waves and when it receives converts electromagnetic (EM) waves into RF currents.

For every radio network, network parameter may be categorized into two parts; one is physical parameter and another is logical parameter. Due to improper combination of physical parameters WCDMA network service may hamper at a large scale. Flowing physical parameter need to tune for optimum network service:

1. Antenna’s heights.

2. Antenna’s Electrical Tilt.

3. Antenna’s Mechanical Tilts.

4. Antenna’s Azimuth or Orientation.

The most probable reason of Physical Parameter tuning is listed below:

a) Poor coverage issue at indoor and outdoor.

b) Signal overshooting issue.

c) Pilot pollution reduction issue.

d) Cluster rearrangement/load balancing or traffic sharing issue.

e) Different purpose optimization such as new site/cell addition and deletion.

WCDMA Radio Network serving area

Antenna Heights: An Antenna height is one of the most significant physical parameter of WCDMA network. By tuning antenna’s height we can control coverage area of WCDMA network. That is antenna height is directly proportional to the maximum coverage area. Depends on the elevation (Sea level height) of geographical surface theoretical value of antenna heights may differ.

One of the alternative soft parameter of Antenna height is Transmit Power. Alternative Physical parameters are Electrical Tilt and Mechanical Tilt.

Antenna height VS Coverage

Antenna’s Electrical Tilt: The antenna’s Electrical Tilt represents an electrical inclination or electrical angle of the antenna from its axis. There are two types of electrical tilts; these are Up Tilt and Down Tilt. Generally electrical Up tilt applies for expand coverage or to strengthen signal and down tilt applies for shrinking coverage. Alternative Physical parameters of Electrical tilt are Antenna heights and Mechanical Tilt.

Antenna Electrical Tilt

Antenna’s Mechanical Tilt: Antenna’s Mechanical Tilt represents a mechanical inclination or mechanical angle of the antenna from its axis. There are two types of Mechanical tilts; these are Up Tilt and Down Tilt. Generally Mechanical Up tilt applies for expand coverage and down tilt applies for shrinking coverage. The tuning impact of antenna’s mechanical tilt is almost similar with Antenna’s “Electrical Tilt”.

Antenna Electrical Tilt vs Mechanical Tilt

Antenna’s Azimuth or Orientation: Generally WCDMA system uses highly directional cross polarized (±45®) antenna. Here, Antenna’s Azimuth or Orientation represents on which direction antenna faces. During the selections of WCDMA antenna we need to consider few antenna characteristics such as polarity, horizontal and vertical beam width, antenna gain, Maximum transmits power etc. Antenna’sazimuth is very useful parameter during the customer complain solution process. If antenna beam width is 65® and three cell site; then the maximum antenna azimuth tuning is ±20®.

Antenna Azimuth tuning proposal

WCDMA BSS CS Drive Test (DT) KPI Measurement and Analysis

2014-08-08T17:36:00.000+06:00

WCDMA BSS CS KPI:

WCDMA BSS CS KPI

BSS (Base station subsystem) CS (Circuit Switched) KPI (Key performance indicator) means for overall WCDMA (Wide band code division multiple access) voice KPI. To measure WCDMA BSS CS KPI you need to use flowing software:

Genex probe or Tems investigation or Nemo Outdoor (Log collection software).

Genex Assistant or Tems discovery or Actix Analyzer (Log analysis software).

Mapinfo professional 11.5 SCP (data presentation software)

Google Earth (Mapping tool).

The flowing equipment requires to collect WCDMA log files from Um interface:

Mobile Station (MS) Sony Ericsson W995 for Tems investigation or Huawei U1251 for Genex Probe.
GPS NMEA (WGS84), Model No: BU353

PC (processing speed minimum core i5).

Inverter (as a portable power source).

CS KPI includes the flowing parameter measurement and analysis:

Call setup success rate (CSSR).

Call completeness success rate (CCSR).

Average call setup time (CST).

Average SQI MOS (Speech quality index mean opinion score) value.

Coverage rate score.

Handover success rate (HOSR).

Blocked call rate (BCR).

Dropped Call rate (DCR).

Log collection procedure and equipment assembly:
To measure WCDMA BSS CS KPI you need at least three mobile station (ms) and a GPS. MS1 and MS2 used to collect SQI MOS value and MS3 used to collect rest of the KPI values. MS3 is in short call mode 30 seconds for each call with 10 seconds as a interval. Number of short call is infinite; that is during the entire test period short call will be continued.

KPI Analysis:
After log collection you need to analyze the log to extract desired raw data to calculate KPI. The required analysis tools described in above. For every KPI there is at least a KPI equation. you have to put exact value from raw data for every variables.

Call setup success rate (CSSR):
Call setup success rate is the rate ration of number of call attempt and number of successful setup. Expressed in percentage.

CSSR = (number of successful call setup/number of call attempt)* 100 %

Call completeness success rate (CCSR):
Call completeness success rate is the ration of number of user defined call end and number of call established.

CCSR= (number of user defined call end/number of call established)*100

Average Call Setup Time:
Call setup time time is the total time required to established a call between to user.
Average call setup time = (total call setup time for "N" number of call/ "N" number of call)*100

Call Setup time

Average SQI MOS value:

Actually SQI MOS (Speech quality index mean opinion score) represents the speech quality of WCDMA CS network. The calculation of SQI MOS, which is defined by the ITU-T PESQ (Perceptual evaluation of Speech Quality) P.862 standard. SQI MOS value ranges from 1 to 5 according to ITU-T PESQ P.862 standard.

Here, score 1 means worst (Very annoying), score 2 means bad ( Annoying), score 3 means fair ( Slightly annoying), score 4 means good (Perceptible but not annoying), score 5 means best ( Imperceptible).

Geographically distributed SQI MOS Values

Coverage rate score:

There are numerous equation to calculate Coverage rate based on the RSCP (Received Signal Code Power) and EcIo, one of the standard equation based on RSCP is given bellow:

Coverage Rate Score(%) = (A%*10+B%*8+C%*6+D%*1)/10

Here, A is 0 to -74dbm

B is -74dbm to -82dbm

C is -82dbm to -98dbm

D is -98dbm to -120dbm

Handover success rate (HOSR):

Actually, there are two types of Handover in WCDMA one is soft handover another is Hard handover. The equation of handover success rate is given bellow:

HOSR = (Number of successful handover/Number of handover attempt)*100

Inverse of CSSR (Call setup success rate) is BCR (Blocked call rate),

BCR= (100- CSSR)

Inverse of CCSR (Call completeness success rate) is DCR (Dropped call rate)

DCR = (100-CCSR)

Related Articles:

How to calculate Call Setup time.
GSM BSS KPI Analysis
RF Planning and Optimization Viva question

Top five overseas destinations for telecom professionals

2014-07-21T04:13:00.001+06:00

Once upon a time, Telecom jobs was most prestigious job compared to the others engineering jobs. But day by day telecom professionals are losing values due to extreme cost cutting formulas adopted by the big telecom giants across the globe. For this kind of scenarios, the most significant reason is massive engagement of manpower vendor in telecommunication industry; usually manpower vendor called third party or Sub-con. Actually they are broker! They are continuously putting pressure on professional on behalf of employer about their salary and remuneration issues by the name of recruitment negotiations and finally they will offer you a contractual position with disreputable condition list. Most of the countries in Asia and Africa, there is no standard pay scale or payment policy for telecom professionals. But situation is not similar for all countries or region. There are few countries said to be heaven for telecom professionals and they propose significant number of jobs for overseas telecom professionals. Please checks bellow the list of countries or regions:

1. Scandinavian region.

2. North American region.

3. Middle East region.

4. Asia pacific region.

5. Western European region.

Telecom professionals ready to be sold

Scandinavian region: There are four countries in Scandinavian region; these are Norway, Finland, Denmark and Sweden. They have highest mobile and internet penetration rate. Actually in today’s mobile communication industries, there is a big contribution of Scandinavian countries. Scandinavian regional countries offers significant numbers of telecom jobs for global telecom professionals for network deployment, operation, maintenance and research. But to grab a Scandinavian job you need at least a bachelor degree from reputed Scandinavian university, also you need a valid work permit to work in Scandinavian region.

North American Region: Actually USA and Canada are two big telecom giants in North American region. Annually, they also offer a huge number of jobs. But most of them are contractual position, to do job in USA you need a valid work permit, also North American countries offer skill migrants program, in which Telecom professionals are prioritized.

M2M regional revenue graph

Middle East Region: Middle East region is said be real dreamland for Telecom professional, actually in Middle East Telecom job market more than eighty percent of the total employees are hired from abroad. Here is a big crowd of telecom professional from India, Pakistan, Iran, Palestine, Russia and Bangladeshi nationals are most common. Flexible work permit, high scale payments and benefits attracts global best talented telecom professionals to work in Middle East region. Actually they offer jobs in all sectors of Telecommunication, including networks, sales and business. The flowing countries which are extensively offer jobs for overseas telecom employees are Saudi Arabia, Kuwait, Qatar, Oman, and United States of Emirates (UAE) etc.

Asia pacific region: Actually Asia Pacific region may be categorized as highly telecom infrastructure developed countries, Semi developed countries, under development countries. Highly telecom infrastructure developed countries in Asia pacific region are South Korea, Japan, Hong Kong, China, Australia, Malaysia and Singapore. They offer significant number of Telecom professionals and research personals. In recent time Japan offers huge number of LTE professionals for nationwide LTE infrastructure development. Australia also gives priorities for telecom professional as a skill migrant. If you have minimum two years working experience in a multinational organization, you can apply for Australia as skill migrants. Of course you should have an undergraduate bachelor degree or post graduate degree with a professional IELTS (Score should be 7 plus).

Telecom Business Professionals

Western European Region: First concern is to work in Western Europe is a valid work permit. If you’ve a valid work permit, you will get a lot of opportunities there. Without a valid work permit working in Western Europe is strictly prohibited and it’s not so easy managing a work permit in Western Europe. To grab a work permit you can took a consultancy from professional placement service provider. But they will charge you considerable amount of money and the process is terrific time consuming. Sometimes it takes ten months to twenty months for a single application.

GSM and WCDMA Single site verification SSV

2014-07-11T05:11:00.001+06:00

Single site verification (SSV) is an audit method, where we need to check the entire KPI (Key performance indicator), coverage and quality for a single radio base station site.

For GSM (Global System for Mobile Communications) network a single site has more than twenty KPI (Key performance indicator), on the other hand for WCDMA (Wideband Code Division Multiple Access) including HSPA plus a single site has more than forty five Key performance indicators (KPI). But all the KPI doesn’t carries the same morals, on the other hand less significant KPI values depends on the major KPIs. So, we often check major Key performance indicators for single site verification (SSV). The entire single site verification (SSV) can be categorized into three subcategory.

These are:

Radio frequency parameter verification (RF verification).

Radio frequency (RF) functionality test.

Drive test and RNO (Radio network optimizer) verification.

Radio frequency parameter audit (RF audit):

RF audit may be classified into parts:

General parameter audit.
Radio parameter audit.

General parameter audit:

In general parameter audit, we have to check the coordinate(latitude and longitude) of radio base station, address, BTS/RBS information (BTS/RBS name, model or version, vendor etc.), Cluster name and type, transceiver configuration (TRX conf), business region name and type, BSC (Base station controller) name, MSC (Main switching center) name, radio base station security guard or gate keeper contract or house owner contract details.

An example of general parameter audit is given bellow:

Figure: General radio parameter audit information.

Radio parameter audit:

In a radio parameter audit, we need to check entire RF parameter such as antenna height, cell azimuth, electrical tilt, mechanical tilt, feeder cable type, feeder cable length, antenna information (model with vendor information), Base station identity code (BSIC), allocated ARFCN (absolute radio frequency channel number) in BCCH (broadcasting control channel), Location area code (LAC) etc.

An example of RF (Radio Frequency) parameters audit is given bellow:

Figure: Radio frequency (RF) parameter audit information.

Tools and software for RF parameters audit:

Digital or magnetic compass.

Digital camera.

Tilting meter.

Fifty meter measuring tape.

Safety tools for rigger.

Google Earth (Software)

Drive test and Radio network optimizer (RNO) verification:

Drive test and Radio network optimizer (RNO) verification is the final step for single site verification (SSV). For SSV drive test we need to unique arrangement for testing terminals.

Tools and Software for single site verification (SSV) drive test (DT):

TEMS Investigation data collection software.

Genex probe

Nemo outdoor.

Mapinfo professional (minimum version 8.5scp)

Microsoft excel (as a SSV template)

Microsoft Power point (As a SSV template)

Mobile Station (MS)

Inverter (as a power source for laptop)

GPS (Global positioning system) receiver.

An example of Drive test equipment arrangement is given bellow:

Figure: Drive Test equipment arrangement.

Drive test (DT) procedure:

Drive test is the most significant event in entire verification process. For single site verification (SSV) drive test (DT); we use three mobile stations (MS) as a testing terminal. This Mobile station (MS) are designated as MS1, MS2 and MS3 respectively. Also we use GPS receiver (global positioning system) as a testing terminal.

SSV Mobile station (MS) configuration:

Mobile station-1 (MS1):

typically MS1 configured in idle mode and locked with the site. For locking Mobile station (MS), actually we have to lock Broadcasting Control Channel (BCCH) for all cell.

Mobile station-2 (MS2):

Typically MS2 configured in dedicated mode short call and unlocked. Usually short call duration is thirty seconds. There is no limit of number of test call. Test call will be continued entire test period with ten seconds as a frequent call interval period. Redial triggers should be Time out, blocked call and dropped call.

Mobile station-3 (MS3):

Typically MS3 configured in dedicated mode long call and unlocked. Usually, there is no limit for long call duration. Redial triggers should be Time out, blocked call and dropped call.

Figure: Command sequence for MS2 and MS3.

Drive Test (DT) Log collection method:

· Start collecting log files from the site access road of SSV (Single site verification) radio base site to neighbor site access road, collect the log files in both way, that means from the SSV (Single site verification) radio base site to neighbor radio base site and neighbor radio base site to SSV (Single site verification) radio base site.
- Run the command sequence for mobile station-2 (MS2) and mobile station-3 (MS3), cover the entire car accessible road surrounding (360 degree) of radio base SSV site. Please check the figure in bellow:
Figure: Single site verification (SSV) drive test (DT) route.

Drive Test (DT) data presentation System:

Event Analysis:
All the mobile station is significant to check performance of radio base site through Drive Test (DT). We have to present major drive test (DT) event in reporting templates. The major Drive Test (DT) events comprises of number of call attempts, number of call established, call setup success rate (CSSR), number of handover attempt, number of successful handover, Handover success rate (HOSR), number of dropped call and dropped call rate (CDR). The presentation of drive test major event analysis is given bellow:

Figure: Drive Test (DT) event analysis

From Mobile Station-1 (Idle mode) SSV data presentation:

From mobile station-1 (MS1), we collect total coverage area of a radio base site and received signal strength (RxLevel) , also we check cell mismatch (feeder cable swap). An example of total coverage area and received signal strength (Rxlevel) of radio base site is given bellow:

Figure: Total coverage area of SSV radio base site.

From Mobile Station-2_MS2 (dedicated mode) SSV data presentation:
Form mobile station (MS2), we check basic functionality test, events, handover sequence number (HSN), mobile allocation index offset (MAIO) of radio base site. MS2 functionality test include call setup, call setup time, Inter Site handover, Intra site handover (handover between radio base sites own cell). We have already discussed about event analysis of Drive Test.

From Mobile Station-3_MS3 (dedicated mode) SSV data presentation:
From mobile station-3, we check received signal quality (RxQual), handover relation status (inter cell and intra cell), call continuity, serving cell footprint of SSV drive test route, overshooting of neighbor cell, planning parameter such as ARFCN (Absolute Radio Frequency Channel number) of BCCH (broadcasting control channel).
An example of serving cell footprint diagram is given bellow:

Figure: Serving cell footprint of SSV DT route.
RNO (Radio network optimizer) and RNP (Radio network planner) Remarks:
RNP remarks: There is no mismatch found within planned and implemented radio frequency parameter, radio base site coverage footprint is satisfactory.
RNO Remarks: Site performance is satisfactory, Key performance indicator (KPI) monitoring will be continued on daily basis.

Abstract:

ARFCN:

"ARFCN means for Absolute Radio Frequency Channel number. There are 124 ARFCN in P-GSM, 175 in E-GSM, 375 in DCS 1800.

BCCH:

BCCH means for broadcasting control channel, it's a down link channel of GSM air interface. BCCH carries system information of radio base station including available features, configuration and identity.

Call setup success rate (CSSR):

"Call setup success rate is the ration between the number of handover attempts and number of successful handover. CSSR is presented in percentage."

Cell ID:

"Every individual cell of mobile network has a unique cell ID for own network, also there is a cell global identity (CGI). CGI = Mobile country code (MCC) + Mobile network code (MNC) + Location area code (LAC) + cell Id (CI)."

Drive Test (DT):

"Drive test (DT) is a network log collection procedure in vehicular mode."

Drive test (DT) Logs:

" Drive test log files include network signaling and event information; which is collected in real time through Drive Test (DT). Also we can collect logs from the BSC (Base station controller) end through IMEI (International Mobile station Equipment Identity) tracing."

Intra site Handover:

"Intra site handover is the handover between two cell of same radio base site.

Inter site Handover:

"Inter site handover is the handover between two adjacent or neighbor sites cell.

Handover Success rate (HOSR):

"Handover success rate (HOSR) is the radio between number of handover attempts and number of successful handover. HOSR is presented in percentage."

Radio frequency (RF) functionality test:

“Radio frequency functionality test means for checking the various functionality of a single radio base site such as general call test (both long call and short call), call continuity test (long call only), network accessibility test (short call), data throughput test, call setup time etc."

Radio frequency parameter verification (RF verification):

“Radio frequency parameter verification (RF verification) means for verifications of installed radio parameter with the previously planned radio parameter.”

Figure: Received signal quality of entire single site verification SSV of radio base station serving area.

How to perform a radio base station site survey

2014-07-06T22:03:00.001+06:00

Site Survey: For a any radio network either it’s WCDMA, UMTS, GSM, Wifi, LTE or any wireless network; survey is a usual, periodic and mandatory task for all operation and planning engineers. For different types of technical aspect, we run different types of survey.

GSM radio base station service status

Radio base station survey may be classified into two type’s one is general objective survey or technical site survey and another is highly objective survey.

Different types of highly objective radio base station survey are given bellow:

Base station subsystem survey (BSS survey)

Radio Frequency survey (RF Survey).

Transmission Survey (Like LOS survey, link budget survey).

GSM Radio Base station

Key performance indicator survey (KPI survey).

Also sometimes we conduct multipurpose survey at a time, let us consider we need to know existing RF (Radio Frequency) status and Key performance status at a time, hence we need to conduct a RF survey (Radio Frequency survey) and Key performance indicator survey (KPI survey) simultaneously.

Technical Site Survey (TSS):

For every survey few data’s are common, such as coordinate of a site, address, site access road, terrain graph etc. In a technical site survey or TSS survey we need to collect almost all types of data (Physical or logical), so that we can represent this data in various graphical presentation formats.

For a Technical site survey you need to collect following data:

Site Name: Please include a site name, an example is “Halishohor R/A,”

Site ID: Please include a site id, an example is “CTG_X_1008”

Address: Please include a site address; an example is “House No-105, Road-06, Block-H, Halishohor, and Chittagong- 1492.”

Coordinates: An example is “22.3358N, 91.8131 E”

“Please include google map screen print with coordinate, an example is given bellow”

GSM radio Base station google view

Site Type: Green Field Tower/Roof Top Tower/ Roof Top Pole..

Equipment room type: Indoor/Outdoor.

"If Green field you should collect tower height or If Roof top pole you should collect building height and pole height."

Access road condition: Normal/ No car access/ Narrow Path (walk only)

"Please include an access road photos, an example is given bellow"

GSM radio base station access road condition

Building Height: 15.5m

Tower Height: 18m

Total height: 33.5m

"Please include a photo of tower with the building, an example is given bellow"

Roof top GSM radio base station

Total area of roof top: 14m X18m

Availability of commercial power: Yes/ No

"If yes please specify the operator name and nearest office address"

Site Layout:

"Please draw the outdoor site layout in two dimensional (2D) formats “AutoCAD is the perfect tool for drawing layout."

GSM radio base station Site diagram or layout

In TSS survey also include the Base station subsystem survey (BSS survey) data, Radio Frequency survey (RF survey) data, key performance indicator survey (KPI survey) data etc. You need not to include all the BSS of highly objective survey data, but most common data should be included, such as from BSS survey includes the flowing data:

Total length of AC power cable.

Total Length of DC power cable.

Total length of AC grounding cable.

Total length of DC grounding cable.

Required Number of mounting pole or bracket for antenna.

Required number of grounding bar or bus bar.

Aviation light status.

“Please include a cabling and latching photos with TSS survey report, an example is given bellow”

GSM radio base station feeder cable latching

From Radio Frequency (RF survey) survey part; include the flowing data:

Antenna Height.
Cell azimuth or orientation.
RF Cable type: CPRI cable/Feeder cable.

“CPRI means for common protocol radio interface”

CPRI cable/Feeder cable length.

Link budget information.

Obstacle information.

"Please check the bellow diagram for obstacle information."

GSM radio base station Obstacle graph

Antennas transmit power.

From Transmission Survey please include the flowing data:

Types of transmission: OpticalTransmission/Ethernet/Microwave (MW)

If Microwave please specifies number of Microwave antenna, number of Indoor Unit (IDU), If Optical Transmission also specifies device type, vendor name, model and maximum capacity.

Existing Microwave (MW) information including diameter.

Microwave (MW) far ends site ID and Site Name.

Please include the transmission topology photos.

Microwave Transmission topology for GSM radio base station

· Free spaces available for installation of new Microwave?

"Answer should be -Yes or No"

From The Key performance indicator survey (KPI survey); please include the flowing data:

Total Traffic: Total Traffic should be calculated in “Erlang”
Site availability: Total on-air time in a observation period.

Major KPI values such as call setup success rate (CSSR), dropped call Rate (CDR), Equipment utilization Factor (EUF), Handover Success rate (HOSR) etc.

Average KPI score for the site:

"Please check the Histogram of last ten days KPI score"

GSM radio base station day_1 to day_10 average KPI values

List of tools and Software for radio base station site survey:

Digital Camera.
Digital or magnetic compass.
50m measuring tape.
Tilting meter.
Digital multimeter.
Google earth (Software)
Mapinfo professional (Software).
Microsoft Excel.
Base station rigging safety tools.
TEMS investigation (Software).
Digital or analog inclinometer etc.

Radio Network Optimization (RNO) based on Customer Complain

2014-07-01T04:02:00.000+06:00

Radio Network: Global System for Mobile Communication (GSM )

RNO: Radio Network Optimization is a process where we need to tune different types of radio parameter to improve radio network accessibility and quality.

For any radio network either it's WCDMA or GSM, it is important to optimize to provide desired services to the subscriber. But in wireless or radio network, significance of optimization carries huge value. I will show you a typical case where we need to optimize to improve network quality and coverage.

Radio base station to customer location and neighbor radio base station

Subscriber complains detail:

Here Subscriber complains that he is facing Blocked call(when subscriber tries to call, it's blocked by the network) and Dropped Call(When subscriber in conversation with called party it's dropped, although customer didn't finished his conversation with his called party).
No service mode (there is no network in subscriber device) or Limited service mode (very few services enabled, which is not sufficient to make a call or provide internet service).
Network fluctuation (That is received signal fluctuates).

Above scenarios occur indoor locations only. But in outdoor received signal Level (Rxlevel) is satisfactory.
GSM Radio Network diagnosis report:

Before optimization signal strength at customer location

Call setup success rate (CSSR) is 20 % that is if subscriber ties to call 10 times he becomes successful for 2 times only.
Received signal level (Rxlevel) fluctuates -15dbm to -20dbm.
Very poor Received signal strength (-98dbm) and received signal quality (6 to 7).
Timing advance (TA) Value 4 to 5.
Poor Signal Quality Index mean opinion score (SQI MOS) around (1.5 to 2.5), but the standard value of SQI MOS is above 3.1.

Reason for bad quality and coverage:

Due to dense vegetation received signal level falls at very high scale.
Customer location is surrounded by metallic body (TIN SN), hence signal fluctuates at broad scale.
Distance of subscriber from serving site is 2.88km, which is blocked by the dense vegetation.
Antenna transmit power is only 30W, where as the system maximum capacity is 45W.
Direction of subscriber from the serving site is 230 degree, but antenna direction is in 180 degree.

Serving radio base station to customer location

Existing Radio frequency (RF) parameter (Physical and logical) information:

Serving antenna azimuth 170 degree.
Serving antenna height is 35m.
Electrical tilt of serving antenna is 2.
Mechanical tilt of serving antenna is 0.
Serving antenna band Single Band (GSM 900 only).
Antenna vendor “AGISSON", Model: A19451811.
Antenna beam width 65 degree (Horizontal) and 8.86 degree (Vertical).
Antenna gain 17.5dbi.
Antennas transmit power 30W.

Before optimization signal strength and received signal quality

RNO process (Solution for the Subscriber):

Serving antenna azimuth should be 200 instead of 170. But for best result it should be directed to the subscriber location at 230. It's not possible because of, if we do that the serving cell will overlap with its neighbor cell, also there will be few null coverage areas.
Transmit power should be 40W instead of 30W. Because of we have to strengthen received signal level (Rxlevel).
Electrical tilt should be 4 instead of 2, because received signal fluctuation largely depends on lower value of electrical tilt. But in AGISSON antenna's electrical tilt inversely proportional to the coverage areas.

RNO Remarks:

For the flowing subscriber, we’ve changed both logical and Physical parameter. After RNO process received signal level (Rxlevel) significantly improved. Finally subscriber was very happy with network quality and coverage.

After optimization signal strength and received signal quality

How to Calculate Call Setup Time in GSM or WCDMA

2014-06-28T17:08:00.000+06:00

Please follow the flowing procedure to calculate call setup time (GSM or WCDMA):

Exporting Log files:

Export the log files in Text file mode with flowing event "setup time (Total,MT)",which is included call attempt, call initiation, call setup, ringing, call established. During the export select only dedicated mode mobile station (MS). Let us consider, you have used three mobile station (MS) during the entire test; in which Mobile station -1 (MS1) was in idle mode, Mobile station -2 (MS2) was in dedicated mode short call, Mobile station -3 (MS3) was in dedicated mode long call. you should select MS2 during the export from log files (Call setup time.log) to text file format as Call setup time.FMT.

Please follow the flowing steps:

First open your TEMS investigation data collection software, then go the "Logfiles" tab and select "Export Logfiles".

After that you will see a mini window in TEMS investigation by the name "Export Logfile", then press "shift + A" after pressing "shift + A" you will see another window by the name "Add Export Order"; then go to "Format tab" select "text file".

Just right site of "Format" bar you will see a button "setup"click on this button, you will see another window by the name "Export to text file".

In this window you will see two tab one is "Information Elements" another is "Option". By default "Information Elements" tab will be opened. Here you will see a selection button "Available IEs", Now you've to select WCDMA/GSM, if you collect Logfiles from GSM network you've to select GSM, or if you collect Logfiles from WCDMA network you've to select WCDMA. Please check the reference photo is given bellow.

How to export log file with TEMS investigation

Now from the selection list select "Call setup time (total,MT)" and double click on it, it will be displaced from left side window to right site window. then double click on the "Call setup time (total,MT)" in right site window and you will see a another window by the name IE settings.

You will see a selection button by the name "mobile". Select MS2 or the mobile used to collect Logfiles of short call. Then press "OK". In "Export to text file" window also press "OK".

Now in ""Add Export Order" window you have to select "input logfiles" from your PC's drive. Then Press "OK". By default exported file will be saved on your PC's Logfiles folder, default folder name will be "Export". Please check the reference photo is given bellow.

How to extract selective mobile station (MS) data from log files

Convert the exported file:

Convert the exported file (Call setup time.FMT) file to (Call setup time.xls) file and save it as call setup time.xls file or MS Excel 1997-2003 workbook. Right click on the exported file then go to "Open with" then go to the Microsoft Excel.

Then go the first row of call setup time short and filter this row.

- Then go the "message type" column select only "Altering" (WCDMA) and "connect"(GSM),.

- After that go to the "Event Name" column then select only "call setup" or "Call established"

- By the finishing of above procedure you will got raw data for "Call setup time" calculation.
- Then copy the above data in a new excel file or sheet.

Select the column "Event Info", then click to Microsoft Excel "Data Tab", then click "Text to column", then select "Dilimited" and convert the data into appropriate format.

Escalation of calculative data from raw data

For Delimitation process use tab, space, coma, semicolon as a separator, our intention is to separate numerical value from the text.

Then arrange the data into appropriate format, like MO call setup time and user setup time, separate the time unit (ms). In a single row please keep only numerical values.

Organized data for call setup time calculation

Then go to sub column "Time" calculate the average MO call setup time and also "user setup time". User setup time is generally a time which requires the user to peak up the incoming call. If the call is peaked up by manually no need to calculate "user setup time". In this case calculate only "MO call setup time" and average value of "MO call setup time is the actual call setup time. For this type of case formula will be:

- Call Setup time = MO Call setup time/ total number of samples

If incoming call is peaked by the automatically predefined system then calculate the both " MO call setup time" and "user call setup time". For this type of case formula will be:

- Call Setup time=(Avg.Value of MO Call Setup time+ Avg value of user setup time)/2

Tools for call setup calculation:

TEMS Investigation (data collection software).
- Mapinfo professional (minimum version 8.5 scp)
  - Microsoft excel (calculation and data arrangement)

Caution:Never try to manipulate any data, because frame number is included with Exported file and in Raw data, so customer can trace you at any time.

Note: This procedure is only applicable for TEMS Investigation data collection software.

If you fell any difficulties during the practice session never fell hesitate to knock me.
Thanks By
Hassan Imam
Facebook
008801914262729

Scenarios of Malaysian Mobile communication Industries

2012-05-07T17:22:00.002+06:00

Malaysia has continuous growth in cellular mobile industry for last one and a half decade. In 2011 Malaysia mobile penetration rate is nearly 121 percent (2011) where as in Southeast Asia it was around 82 percent (2011). So, mobile penetration rate in Malaysia higher than neighbor countries. In 2014, mobile penetration rate in Malaysia is around 141 percent. But to escalate actual mobile penetration rate ITU (International Telecommunication Union) conducted a survey in Asia pacific region in which 41 percent of Malaysian subscriber has multiple mobile phone or land phones. Where as in Singapore 21 percent subscribers has multiple mobile devices.

On the other hand number of smart phones user significantly increases in last few years, According to the "TigerMine Research" smart phone penetration in Malaysia is around 80 percent. Where as in Southeast Asia around 87 percent subscriber uses featured phone(2014).

According to the Geo socioeconomic report (2012), telecommunication industries contributes on Malaysian GDP at a higher rate (around 5 percent) compare to the Asia Pacific regional countries. Like in Singapore telecommunication industries contributes in GDP at 3.5 percent, in Thailand 3.5 percent, in Hong Kong 3.3 percents, in South Korea 2.9, in China 2.6, in Indonesia 2.1 percents respectively. The average value is 3.2 including Malaysia. So Telecom contribution in Malaysian GDP is above average.

If broadband penetration rate of Malaysia 10 percent increases, it will contribute on GDP 1.5 percent to 2 percent. On the other hand if mobile subscriber (voice) penetration rate 10 percent increases, it will contribute on GDP 0.9 percent to 1.3 percent. But more important is that if 1USD spent on mobile, it has impact 3USD on total economy; especially electronics, service, construction and manufacturing etc. So, in Malaysian business ecosystem Telecommunication plays vast role. Malaysian government aware about this issue, hence they welcome any foreign investment on Telecom.

Government has a plan up to 2020 developing their telecom infrastructure; hence all the telecom companies are in pressure situation to develop their network to provide seamless data. In 2009 telecom has contribution on gross national income (GNI) 22billion. In 2020 it will be more than 57 billion. But to develop infrastructure they have to invest more than 68.9 billion within 2020.

RF Planning and Optimization VIVA question part-2

2012-04-12T13:02:00.008+06:00

Figure: Photo of Radio Base Station

What is the Panoramic view and why it's important ?

Answer: Panoramic view is the 360 degree view of a given point or point of interest. We often need to know the surroundings of a proposed wireless site or existing due to fresh installation, expansion or swap. Because we need to declare the cell azimuth of site on the basis of traffic potentiality, hence we can make a good assumption from the panoramic view about the potential traffic.

What do you know about TSS ? Describe in brief.

Answer: TSS means for Technical Site Survey. TSS deals with the existing site information like radio parameter,radio equipment,power equipment, system configuration, cable length, Type of site etc. In TSS there is some mandatory data also like site coordinate, site address, site view, site access information etc.

What is the RF (radio frequency) antenna parameter ?

Answer: RF (Radio frequency) antenna parameter includes height of antenna, azimuth of antenna, Electrical tilting, mechanical tilting, type and size of antenna, TMA (Tower mounted amplifier) information, RRU (Radio remote unit) information, feeder cable issues (Type, length and size) etc.

What is LOS, write down few names of LOS tools.

Answer: LOS means for Line of Sight. It's important due to Microwave Planning and for a successful microwave link you should have to confirm that LOS is clear.
List of few LOS survey Tools:
GPS / DGPS
• Binoculars (10 kms and more)) with compass built in
• Magnetic compass
• Digital camera
• Heliographic Mirror (Optional)
• Digital Inclinometer
• Digital altimeter (barometric)
• Digital stop watch
• Measuring Tape 100mts
• Mobile handset
• Safety kit etc.

Related articles

RF Planning and Optimization VIVA question part-1

2012-03-24T16:18:00.008+06:00

What is link Budget Analysis used for in GSM?

Answer:
Link budget analysis is used for the path balance between both up-links (Transmitter)
Down-link(Receiver) part of the network. Imbalance in up-link and down-link causes a frequent call drop and decreases the Call Complete Success Rate (CCSR).

2. How is path loss taken into calculation ?

Answer:

This is the total path loss occurred due to multipath propagation of the signal between transmitted signal and the received signal level.

Few important reasons for path loss:

Reflection

Deflation

Scattering

Rain fading etc.

3. What is capacity planning?

Answer:
This is process of increasing traffic by adding Transceivers (TRXs) traffic channels and proper use of frequency reuse pattern. By adding new BTSs.
4. How is site selection done for planning and site acquisition?

Answer:
After nominal cell planning with the geographical coordinates identifying best site candidate in a geographical area is the process of site selection. Selecting best sites depends on number of issues:
- Site distance from nominal.
- Site availability.
- Major obstacle.
- Type of site Rooftop (RT), Greenfield (GF), Greenfield rooftop (GFRT), here rooftop will be top prioritized.
- 24/7, 365 site access permits or not.
- Site distance from car access able road.
- Lift avail ability in rooftop (RF) sites etc.
5. What is optimization? What are the tools used for optimization?

Answer:

Once GSM network is integrated in order to achieve proper planning prediction

RF parameters Optimization is done.

Drive test tool, Planning tool and Post processing tools are used for optimization.

Drive Test Tools:
- Tems investigation data collector.
- Tems route analyzer.
- Nemo
- Actrix
- Cell planner
- Mapinfo
- Google map.
6. What is system information?
Answer: System information is from BTS sent to Mobile for the idle mode and dedicated mode of the call for call management.

7. What is bench marking in GSM ?

Answer:
Bench Marking used for comparing performance of different network for quality and call performance parameters.
8. What is Erlang table?
Answer:
This is the table for calculating Traffic in erlang for number of channels. To calculate Erlang we often consider blocking probability is a constant value, but in practice it’s not, It varies on Traffic and other KPI issues.
9. How do you optimize a network using OMCR performance data?

Answer: Proper increase in call success, and increase in handover success performance and drop call reduction performance, error log analysis etc.

10. What is daily report and traffic?

Answer:
This is the report obtained in OMC for the performance of all BTS about traffic and resource utilization.

For More question: VIVA Question

GSM Base Station Subsystem (BSS) KPI analysis

2012-03-17T15:57:00.014+06:00

GSM BSS KPI analysis

KPI means for key performance indicator, which is measure from all the related aspect of network such as call setup success rate (CSSR), Handover success rate (HOSR), Paging, network access, congestion etc. From KPI report Radio Network Optimizer’'s took decision or provide prescription for the network. For KPI analysis usually data is collected from drive test of Radio Access Network (RAN), error log of network equipment and Base Station Controller (BSC) data. After combining data we can draw symmetric graph using GSM KPI tools.

Short lists of GSM KPI tools:

Mapinfo.

TEMS Investigatation.

TEMS Route Analyzer.

Genex Probe.

Genex Assistant.

Google Earth

Google Map

NEMO.

ACTRIX Analyzer.

Microsoft Excel and Microsoft Access

There are numerous KPI and optimization tools for GSM network, but above tools are widely used. From BSC we collect traffic data and system performance data, this data represent salient status of the network, resource utilization, Hardware load etc. After analyzing this data we can make decision on network planning, network monitoring and network performance.

BSS KPI Issue:

Paging success rate

Standalone dedicated control Channel (SDCCH) availability rate.

Standalone dedicated control Channel (SDCCH) congestion rate.

Immediate assignment success rate.

Standalone dedicated control Channel (SDCCH) call drop rate.

Traffic channel (TCH) availability.

Traffic channel (TCH) call drop rate.

Traffic channel (TCH) congestion rate.

Traffic channel (TCH) assignment success rate.

Handover Success rate (HOSR)

Call setup success rate (CSSR)

Call complete success rate (CCSR)

Call setup delay (Ideal value of call setup time is bellow 3.5 seconds).

Above thirteen issues are important for network performance and this issues are directly impacts on the user experience about the network. On the other hand every single issue is depending on the multiple variables and as well as each other. Like low success rate of Handover (HOSR) decreases Call complete success rate (CCSR) and increases dropped call rate (CDR). Lower value of KPI depends on flowing:

Geo and Meta data issues.

Network Planning and implementation error (Such as cell mismatch, mismatch on RF parameter and antenna orientation, High VSWR and DTF etc ).

Hardware failure (BTS/RBS down time or off air time) or Hardware Capacity issues (limited capacity of hardware responsible for network congestion, it's also decreases network access rate).

Resource constraint (Frequency Band and Absolute radio frequency channel number - ARFCN, low height for serving antenna, low transmission capacity).

A GSM KPI’s widely depends on the network parameter; such as azimuth, mechanical tilting, electrical tilting, feeder length, feeder type and antenna height etc. Mismatch on network parameter decreases the KPI value. KPI is also depends on the core and transmission network parameter.

Note: GSM network may classified into three parts, these are

Radio access network (RAN)

Core network (CN) and

Transmission network (TN).

Ideal value of KPI is 100, expressed in percentage. In practical it’s not possible to achieve 100. But you should try to increase KPI values as much as possible. A good example of high KPI is Airtel network in Bangladesh. It’s about 94% in R2 region; R2 region is eastern belt of country, from Sylhet to Cox’s Bazaar including Comilla and Chittagong.

Basics of RF Engineering

2012-03-13T18:00:00.008+06:00

Radio Frequency engineering deals with radio waves ranges from 3 KHz to 300GHz.Today's communication network largely depends on the wireless radio technologies. Now a day’s Nine out of Ten subscribers are connected to the network through radio wave. The use of Radio wave not only for access network, transmission network also uses Radio frequencies.

Today's cellular networks are based on the Radio waves both for Transmission and access network. There are numerous communication technology based on Radio like today’s Wifi (802.11b), WiMax (802.16d and 802.16e), Global System for Mobile (GSM), Third generation cellular mobile network (3G), fourth generation cellular network (4G), Long term evaluation(LTE), High Speed Packet Access (HSPA) and there are lot more new communication technology hugely depends on Radio technologies.

Artificial Satellites are uses radio waves to transmit and receive different types of information such as weather, geographical positioning system (GPS), entertainment (video and music), as well as data and voices. Today’s Radio waves also uses for cooking (Like 2.5GHz used in Microwave Oven), medical diagnosis, scientific, military and research etc. For extensive use of Radio waves we have shortage of Radio spectrum. Hence efficient use of Radio waves is important. For this reason today’s most efficient network means most spectrum efficient network. We have lot of technologies to use Radio Wave efficiently, different types of modulation scheme and coding scheme developed, error detection and correction procedure also developed. Some of the experts’ views are that High frequency is harmful for human body and plants, but there is no efficient and affordable alternative developed yet.

The unique properties of RF signals are

Amplitude
Frequencies
Phase
Wavelength
Polarity.

In which frequency and wavelength are inversely proportional. That means if frequency raises wavelength decreases. To deploy a wireless network, you need to choose frequency ranges or spectrum. To use wireless frequencies you need to get frequency allocation from concern authorities, like in USA; the concerning authority is FCC (federal communication committee). On the other hand different frequencies are reserved for the different type of communication technology. Like for GSM 900 frequencies are reserved from 890MHz to 960Mhz. In which 890MHz to 915MHz for uplink and 935 MHz to 960MHz downlink. In between frequency ranges from 915 MHz to 935MHz these frequencies are used as a guard band. Guard band is important for duplex communication to separate uplink and downlink frequencies. It may be treated as a road divider in a two way communication path. Ok, we will discuss lot more about this issue on letter articles.

Actually RF engineering comprises of huge complex task. Don’t worry; all the work is sequential and related to each other. RF Engineering may be split in three consecutive tasks. These are:

· Radio Network Planning and Implementation (RNP).

· Radio Network Optimization (RNO).

· Radio Network Quality and performance analysis (KPI analysis).

The entire above task may be segmented a group of series work. Like for Radio Network Planning you need to arrange prior data and need to understand capacity and requirement of network. Prior data may be classified into two parts; these are Meta data and Geo data.

Meta data consist of humidity, average rain fall, speed of wind, temperature and variance of temperature etc. All the data collected year to year; because Meta data changes season to season. Geo data consist of geo coordinates, elevation and types of terrain etc.

802.11 Network Implementation

2010-06-11T04:01:00.001+06:00

-->

21% question associated with the Almost 802.11 Network Implementation 802.11 Protocols and devices include the flowing:

4.1 802.11 Network Design, Implementation, and Management

6.1.1 Identify technology roles for which wireless LAN technology is appropriate

o Corporate data access and end user mobility

o Network extension to remote areas

o Building to building connectivity-Bridging

o Last-mile data delivery – Wireless ISP

o Small Office/ Home Office (SOHO) use

o Mobile office networking

o Educational / class room use

o Industrial –warehousing and manufacturing

o Healthcare – Hospital and Offices

o Hotspots – Public network Access

4.2 802.11 Network Troubleshooting

6.2.1 Identify and explain how to solve the flowing wireless LAN implementation challenges

o Multipath

o Hidden Nodes

o Near/Far

o Narrowband and wideband RF Interference

o System Throughput

o Co-channel and Adjacent-channel Interference

802.11 Protocols and Devices

2010-03-30T03:02:00.000+06:00

802.11 Protocol Architecture
Almost 14% question associated with the 802.11 Protocols and devices. 802.11 Protocols and devices include the flowing:
Summarize the processes involved in authentication and association

• The 802.11 State Machine.
• Open System and Shared Key Authentication.
• Association, Reassociation, and Disassociation.
• Deauthintication.
• Shared Keys.
• Certificates and PACs.
3.1.2 Define, describe, and apply the following concepts associated wireless LAN service sets
• BSS & BSSID.
• ESS & ESSID/SSID.
• IBSS.
• Roaming.
• Infrastructure Mode.
• Ad Hoc Mode.
3.1.3 Explain and apply the flowing power management feature of wireless LANs
• PSP Mode
• CAM Mode
• TIM/DTIM/ATIM
3.2. 802.11 MAC & PHY Layer Technologies
3.2.1. Describe and apply the flowing concepts surrounding wireless LAN frames
• 802.11 Frame Format vs. 802.3 Frame Format
• Layer-3 Protocol Support by 802.11 Frames
3.2.2 Identify methods describes in the 802.11 standard for locating and maintaining connectivity with an 802.11 Wireless LAN
• Active Scanning(Probes)
• Passive Scanning(Beacons)
• Dynamic Rate Selection
3.2.3 Define, describe and apply 802.11 modes and features available for moving data traffic across the RF medium
• DCF
• CSMA/CA vs. CSMA/CD protocols
• RTS/CTS and CTS-to-Self protocols
• Fragmentation
• Wireless Multimedia (WMM) certification
3.3 Wireless LAN Infrastructure and Client Devices
3.3.1 Identify the purpose of the following wireless LAN infrastructure devices and describe how to install, configure, secure, and manage them
• Access Point
• Wireless LAN Bridges
• Wireless LAN Switches
• PoE Injectors and PoE-enabled Switches
• Residential Wireless Gateways
• Enterprise Wireless Gateways
• Enterprise Encryption Gateways
• Wireless LAN Routes
• Remote Office Wireless Switches
• Wireless LAN Mesh Routers

3.3.2 Describe the purpose of the following wireless LAN client devices and explain how to install, configure, secure, and manage them
• PCMCIA Cards
• USB, CB and SD Devices.
• Serial and Ethernet Converters
• PCI and Mini-PCI Cards
• Card Adapters
• Wireless workgroup Bridges

802.11 Regulation and Standards.

2010-03-23T12:02:00.000+06:00

Almost 12% question associated with the 802.11 Regulation and Standards. 802.11 Regulation and Standards includes the flowing:
2.1 Spread Spectrum Technologies
2.1.1 Identify some of the uses for spread spectrum technologies
• Wireless LANs.
• Wireless PANs.
• Wireless MANs.
• Wireless WANs.

2.1.2 Comprehend the differences between, and explain the different types of spread spectrum technologies.

• FHSS
• DSSS
• OFDM
2.1.3 Identify and apply the concepts of how spread spectrum technology
• Co-location.
• Channels.
• Carrier Frequencies.
• Dwell time & Frequencies.
• Throughput vs. Bandwidth.
• Communication Resilience.
2.2 IEEE 802.11 Standard.

2.2.1 Identify, explain, and apply the concepts covered by the IEEE 802.11 standard and the differences between the following 802.11 clauses:
• 802.11
• 802.11 a
• 802.11 b
• 802.11 d
• 802.11 e
• 802.11 F
• 802.11 g
• 802.11 h
• 802.11 i
• 802.11 j
• 802.11 n
• 802.11 s

2.3. 802.11 Industry, Organization, and Their Roles.

2.3.1 Define the roles of the following organizations in providing direction, cohesion, and accountability within the wireless LAN industry.
• FCC.
• IEEE.
• Wi-Fi Alliance.

Radio Frequency (RF) Technologies

2010-02-09T18:03:00.000+06:00

Radio Frequency (RF) Technologies
Almost 21% question associated with Radio Frequency (RF) Technologies. RF Technologies includes the flowing subsection:
1.1 RF Fundamentals.

1.1.1 Define and explain the basic concept of RF behavior.
1.2 RF mathematics.

1.2.1 Understand and apply the basic components of RF mathematics.
1.3 RF signal and antenna concept.

1.3.1 Identify RF signal characteristics, the application of basic RF antenna concept, and the implementation of solutions that require RF antennas.
1.3.2 Explain the application of basic RF antenna types and identify their basic attributes, purpose, and function.
1.3.3 Describe the proper locations and methods for installing RF antennas.
1.4 RF Antenna Accessories.

1.4.1 Identify the use of the flowing wireless LAN accessories and explain how to select and install them for optimal performance within FCC regulation.

CWNA Examination Syllabus

2010-02-09T17:52:00.000+06:00

Radio Frequency (RF) Technologies

802.11 Regulation and Standards.

802.11 Protocols and devices.

802.11 Network Implementation.

802.11 Network Security.

802.11 RF Site Surveying.

Today’s Wireless LAN Standard_IEEE 802.11g

2010-02-04T11:28:00.000+06:00

IEEE 802.11g- describes data transfer rates as fast as IEEE 802.11a using the same technologies as, and boasts backward compatibility to, 802.11b, allowing incremental upgrades. The 802.11g standard was ratified by the IEEE in June, 2003. Wi-Fi certification has been extended to include 802.11g. More details ....

Today’s Wireless LAN Standard_IEEE 802.11a

2010-02-04T11:13:00.000+06:00

IEEE 802.11a- specifies much faster data transfer rate than 802.11b,but lacks compatibility with IEEE 802.11b. 802.11a uses the 5 GHz UNII frequency bands. This standard was ratified by IEEE in 1999 as an amendment to the original IEEE 802.11 standard. Wi-Fi product certification has been extended to include 802.11a. More details . . .

Today’s Wireless LAN Standard_IEEE 802.11b

2010-02-04T10:52:00.000+06:00

IEEE 802.11b-modifies 802.11 2.4GHz DSSS (Direct sequence spread spectrum) to include faster data transfer rates up to 11Mbps.This standard was the first to be widely promoted as wi-fi Alliance.802.11b was ratified by IEEE in 1999 as an amendment to the original IEEE 802.11 standard. More details.....

Today’s Wireless LAN Standard(IEEE 802.11)

2010-02-02T19:36:00.000+06:00

IEEE 802.11-the original wireless LAN standard that specifies one or two Mbps data transfer rates using both 2.4GHz unlicensed radio frequencies (RF) and infrared light-based transmission technologies.The RF technologies include both frequency hopping spread spectrum (FHSS) and direct sequence spread spectrum (DSSS). This standard was ratified by IEEE in 1997, revised vin 1999, corrected again in 2001, and finally reaffirmed in 2003.

Today’s Wireless LAN Standard

2010-02-02T19:21:00.000+06:00

-->Emerging technologies will require standards that describe and define their proper behavior.The challenge for manufacturers and standards makers alike will be to bear on the problems of interoperability and compatibility.More details….

Radio Frequency Engineering

WCDMA breathing effect and Coverage - Capacity trade off

GSM Radio Parameter Details and Score evaluation from Drive Test (DT) end

Different types of Voice quality measurement systems and score evaluation (GSM and WCDMA)

WCDMA Network’s Physical or Antenna Parameter Optimization Procedure and Purpose

WCDMA BSS CS Drive Test (DT) KPI Measurement and Analysis

WCDMA BSS CS KPI:

Top five overseas destinations for telecom professionals

Related articles

GSM and WCDMA Single site verification SSV

Single site verification (SSV) is an audit method, where we need to check the entire KPI (Key performance indicator), coverage and quality for a single radio base station site.

Radio frequency parameter audit (RF audit):

General parameter audit:

Radio parameter audit:

Tools and software for RF parameters audit:

Drive test and Radio network optimizer (RNO) verification:

Tools and Software for single site verification (SSV) drive test (DT):

Drive test (DT) procedure:

SSV Mobile station (MS) configuration:

Mobile station-1 (MS1):

Mobile station-2 (MS2):

Mobile station-3 (MS3):

Drive Test (DT) Log collection method:

Drive Test (DT) data presentation System:

Event Analysis:

From Mobile Station-1 (Idle mode) SSV data presentation:

From Mobile Station-2_MS2 (dedicated mode) SSV data presentation:

From Mobile Station-3_MS3 (dedicated mode) SSV data presentation:

RNO (Radio network optimizer) and RNP (Radio network planner) Remarks:

Abstract:

ARFCN:

BCCH:

Call setup success rate (CSSR):

Cell ID:

Drive Test (DT):

Drive test (DT) Logs:

Intra site Handover:

Inter site Handover:

Handover Success rate (HOSR):

Radio frequency (RF) functionality test:

Radio frequency parameter verification (RF verification):

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How to perform a radio base station site survey

Site Survey: For a any radio network either it’s WCDMA, UMTS, GSM, Wifi, LTE or any wireless network; survey is a usual, periodic and mandatory task for all operation and planning engineers. For different types of technical aspect, we run different types of survey.

List of tools and Software for radio base station site survey:

Radio Network Optimization (RNO) based on Customer Complain

How to Calculate Call Setup Time in GSM or WCDMA

Exporting Log files:

Convert the exported file:

Tools for call setup calculation:

TEMS Investigation (data collection software).

Mapinfo professional (minimum version 8.5 scp)

Microsoft excel (calculation and data arrangement)

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