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I

"elecommunication statistical data base: i a case study on microcomputers

and M. MINGES -\ .

packages made them an attractive option tion 61 powehiu comphter' natuware, Overview for supporting telecommunication ana- easy-to-use analysis and presentation

lvsts' requirements. Simple data base software tools as well as sophisticated

by V. 8. DANG

T HE design and subsequent imple- mentation of telecommunication

statistical data bases (TSDB~ on micro- computers raise several issues. In this article, we share our experience in devel- oping a fairly large and comprehensive system.

systems such as base and spreadsheets such as Lotus 1-2-3 and Excel were used to store data. Not much thought was given to data management because requirements were simple. As the amount of data grew and user require- ments changed, the limitations of these systems became apparent. Problems included inflexible file structures,

data base management systems available on microcomputers.

Case study

Continuous improvements in micro- Introduction computer hardware and software have made the realization of TSDB particu-

extensive programming, data redun- dancy, limited data management tools, The project ofice of the regional African

awkward interfaces to external applica- satellite communication system for the

&umarrd&p/eNeSb~otpb17i~m. development of Africa (RASCOM), The end result was that telecommunica- headquartered in the International me-

tion analysts found themselves devoting communication Union (ITU), is con-

more and more time to overcoming the ducting a feasibility study on an African

limitations of these systems, leaving satellite system. The project office has

them less time to analyse the data. collected large amounts of statistical data from countries participating in the

lady attractive in the telecommunica- tion eowiwdment ituowriig to 'amaef-

kmbly reduce development time of the data [base and create efficient links between k -data management and data analysis. t 1

!Pad experience study. Storing the data in a computer- Faced with the tasks of designing and based system would increase the produc- implementing a sizeable telecommuni- tivity and efficiency of the project office cation statistical data base, the intention in processing the quantity of informa- was to take advantage of the new genera- tion collected.

low cost of microcomputers coupled the availability of relatively inex-

ive, user-oriented application

TELECOWNICA TION JOURNA L - VOL. 56 - XI11989 7 1 3

Requirements, data stmctnre and size of the data base

The project office wanted the data stored on a microcomputer-based system because of its relatively low cost and pos- sible use by the participating countries and regional organizations as well as the number of applications available on microcomputers. The variety and amount of data coupled with the user requirements, particularly operation on a microcomputer, posed a challenge. There was a wide range of topics to be considered including socio-economic, telephone and telex, satellite, sound and television broadcasting and maritime radio. The structure of the data ranged from time series (for example, number of telephones) and matrices (for example, yearly telephone traffic be- tween countries) to disaggregated nati- onal statistics (that is, the make and capacity of local telephone- exchanges) and reference information (such as the manufacturers of telephone equip- ment). Data covered by these topics had to be stored for each of the approxima- tely 50 countries participating in the study. The minimum size of the data base is estimated at 50 000 records.

Design

Work on the design of the regional Afri- can telecommunication data base (RATDA), name given to the RASCOM data base, began in March 1988.

The RASCOM data-contained in country reports consisting of statistical tables designed by the project ofice- was analysed in order to design an effio ient system that would not affect the way the project office was accustomed to deal with data. The aim was to create a flex- ible relatively simple data base to incor- poxate any new needs as the grobct gro- gressed. During this design phase, data was-or&&ed by toac and relations between topics identifed, redundant information weeded out, and spedal features designed to support &ta types, data integrity and multilingudity.

A data base system was required that would support both the topical organiza- tion of the RASCOM data and relation- ships between topics. For example, in order to determine telephone density (the ratio of telephones to population multiplied by loo), the system needed to retrieve the number of telephones from the telephone service topic for the year and country specified, divide it by the population from the demography topic for the same year and country, and then multiply the resulting figure by 100.

This example illustrates an important requisite of the system, namely the abil- ity to perform dynamic calculations. The telephone density is a derived data calcu- lated from two basic items stored in the system, that is the number of telephones and the population. Although it could be stored in the data base, this would create data duplication and compromise data integrity. Data is duplicated because there is no need to store telephone den- sity; it can be derived. Data integrity is compromised because if the number of telephones or the population is revised, the stored figure for telephone density will then be incorrect.

Implementation

Relational data base system

A relational data base system enables topics with different file structures to be linked while hiding the complexity of how it is done from the user. It uses a standard data definition and query lan- guage known as structured query langu- age which reduces development time and makes the data base compatible with a number of different packages.

Aprototype, implemented ina relational data base system on a microcomputer, was initiated in July 1988. It was demon- strated at the RASCOM Interim Execu- tive Committee meeting in October 1988 in Addis Ababa, Ethiopia. This Commit-

tee comprises expert representatives of the AEtican Ministers responsible for telecommunications. Completion of the data base was scheduled for the summer of 1989 although entry of the large amount of data will continue beyond that date.

System management

One of the benefits of relational data base systems are the extensive &ta management features they provide. The main benefit is the ease by which the data base can be modified to incorporate addition, deletion or modification of topics or data elements. Other benefits include security options, data base backup and recoverg and data integrity- values have to be within a certain range- as well as maintenance of all topics and data elements in a data dictionary. An up-to-date data dictionary can be con- sulted by users at any time to assist them in retrieving data and understand its meaning.

Presentation

Presentation tools include generation of tables and linking of RATDA into word processing and desktop publishing appli- cations. Currently, close to 100 tables designed by the RASCOM project office can be printed from RATDA onto a laser printer using different fonts, typefaces, and orientation. These pre-designed tables or the results of user queries can be output to disk fdes in various file exchange formats and imported to word processing packages for incorporation into reports or desktop publishing packages for additional formatting.

Statistical anaIysis

Besides basic mathematical operations such as addition, subtraction, multiplica- tion and division, there are a number of statistical and mathematical functions available within RATDA including sum- mation, average, maximum, minimum, standard deviation, variance, exponen-

tial, logarithms, mnatunrl Io&aithms, powex, square root and absolute value.

Data can easily be extraded from RATPA ia standard Fie ex~btw#e fix- mats for further d y s i s by sp~ds$eet iurd for- p&ages. Por emple* RATDA data has been expofled to Excel, a spreadskeet pwlmge widely aaed within the ITU. BQSUSS extemive presentation wit3 graphics capabilities, Exoel &o prwidm a mmnber of fha- ciai, lxa&%mw lwi* rrtatisticat and ~ ~ ~ ~ o M M B B M ~ Rimdom - Wh have also W e d RATDA to the GAS 10 software [7for time series mats- sis, remssioa, tntffic fma&ting & erlang cal&tions. Tfrese software rou- tines require data to be in a set f o m t which was predeslgned go that there is a tramparent link between them and IUTDA.

RATDA can be used *th most statistical &psis padages. For exmble, it has been intefitwd wit-$ SPSSTPC +, a popabr commercial statistical anaIysis application.

A lisa of all of IWIDAs features is beyond the sppe ofthis W e . The fol- lowing are pas thhly relevant to tele- cammdcation statis&%.

Country

The International Orgmhtion for Stan- ddkation (ISO) 34li@t alphabetic &s am med to distinp;nish country &&L This allows a sholr mgmonic code to be used for storing and retrieving data. These-codes are mWed to a country topic c&nkiniag thrt English and French 08zu1tfy m e used for presentation of the data Aaot4.k~ Q a n a of the IS0 &e is data ~&TY:- bwew it a- pWia e~cbmge of data arrith . . that Berve doptd it. For

p~sibiHty of hta from clther UniM N a t i ~ sped&ed &es to complemmt RATnA.mcio- emnomic series is under study.

Data types

A special topic, again based on S O reaommendations, was created to iden- tify the variety of data found in telwm- d ~ t i o n s4atistics. Computer system gemally distinguish and allow opera- tions on only W t e d types of data such as tsepr* dedmd, chaaoter, money, date and time. %lecoa3~Wcation data Made amu& wider q e of tgpss such as &eqwmy, geogmphies5 co-ordinates, s o w aenypewtule, pawer, length and area. The aMty to sped@ additional data types A& ody makes the system easier to wrfeW but also makes it rnwe Bxible by m&ollina; valid men- tions (for example, a frequency data type WOUfd be d e to recognize its dmensi- on& uni8 (Hz, kHz, MEzIldKz, GHz) and su- opmtiom such as o o n v e ~ 6 ~ o n H z t u B ~ z ) ;

A special RATDA da&t type is evwmet- ated. This ibntifim Cta whid clun only have alimited set &values, Fbrexmi'ple, a television system ctln ~ e n t f y be B L , SECAMor XlSC. This fatwe sup- ports data integri€y and stand-on since the value can only be chmn fPtMl a standard set of values reducing ba5a eatry erron.

One of the user requirements was &at the system must support both English and French. This was done by designing the country, data me md other refer- ence topies with both Eng&h and Frewh C E e ~ p ~ . When t$e syirbm is run, wers are asked which 1- they want to work with. Depending on the response, the appropriate descriptors are displayed.

e Time series

Tmo sedta data are important to tele- txmlnoai~~~t-jan s&tisticdll da* bages b a e a r a a e r n g n y d w p v - a ezie~ ofhirrt&d darh te pmdwx f o ~ - GW~S. M@ut Mof the topi- in RATDA eon* yearly time smies data. 8umt

for time series L ~omp1etely Oen%le; a i f

yea^ can easily IreadWorc%&Watrtny time and does not mpke d D c a - tion to the system. F m m t e : , "layers" of overlappin@ pa's Me &o supported. For example# it is w&"ble tO hav~ forecasted gross na&x%d p d u c t i (GNP) F5wes from CSiEemnt fwmxst- iaiJ techniques or data c0llect.d Erosl Werent sources such as popuWan figures from the country as well s the United Nations.

A majar challenge wifh telecom~~unim- tion ~Wstim is detennbi~lg the level of aggregation. This has imptirtant repet- cussions on oompate~ mgourcm and the wmpfexity and coasisteflcy of the data k. %1ecommWei8tioai staWm imlmbs both macro and micro data. Mam W e t x m m e t i o n data is agge$ated at the country level aid is useW f o ~ r e g i d anil international contlparisons. An emnp1e of macro teleeonrrmnnieation &ta is the tow number of telephone eahnges for diffirent wantries. ~~ W e c ~ w ~ ~ t t i o n data is di-gat- ed and useful fox in-depth national am- lysis. One example is a list of each tele- phme exdxmge in a country she* its location, the year it was eomdssioned, the manufmturer snd Its atpacity.

One of the advantages of dimaggregated national data is t h t it an be EtSied to derive macro level data. Us& ttEe example abcwe, the nxmber' am? to@ capacity of a ~~ telephone exchanges is SEbtdned by Wcbg a m t of the indiyidud exskangm and ad* up tb wpt&y (table 1). Howver,

smxw extra e a ~ t l ~ g: and && storage resoouoes, U also re-s s~b&mM data entry resowam. Finally,

T E t E C O ~ N I C A 7 7 0 N JOURMAL - VOL. 56 - X1/1981) 7 1 5

These problems are inherent to relati- onal systems; the next generation of data base management systems-object- oriented-is expected to handle them.

There are a number of refinements to be considered for future telecommunica- tion data bases.

A data base server utilizes the power gf microcomputers, tlle load area network and data base d b m e tedmalogies for providing e@eient mMXtide ttccess to dif- ferent data bases. This wili enable access to data which is physically dispersed in

Exchange Services, provides access facii- ities including solutions for external A c b Q w l e d g a d users to access data bases located in the ITU. The views and conclusions sostained in

this document are thm of the apt5Mrs Objee4*rieated s~~shms and should not be interpreted as mpra- D ~ e ~ o p ~ e ; n ~ in an of computer senting official policies, either e ~ m s e d so-e h- ob&ct-&e&& sys- Or implied From the nu- tems are Fitwing do& fmm a k c to cmmrcial applie8tionsns TW will allow more flexibility in the design of telecommunication data W, gr&m adaptability to chaaigin$ user require- ments and a systematic approach to the integration of data management, antlly- sis and presentation.

We wish to thank Messrs L. Goeloer far his valuable support and suggestions* and A. 0. Taylor for providing RASCOM materiaI anel reviewing RATDA user requirements.

(Original language: English)

the ITU micro&pnter ne-k-each a-o11 containing dUTeren2 data-at the same 1'1 CCPrr : Banning Data and Formasting

Methoe, GA!3 10 Handbook (VO~S. 1 time.

If careful consideration is given to design 2, and 3), ITU (Geneva, 1987)

WiaBows ', aspects and choice of data base software,

These intuitive, graphics-based displays am e-etsy to l e m and language-indepen- dent which increase productivity. Also, windows-based interfses W e it posh sible to deal with a number of applica- tions operating at the same time. For example, under a windows-based inter- face, an analyst can emcurrently use dB- ferent data bases, prw~tation and ana- lysis packages, all with aconsistent inter- face.

Pe&maie d d p

Smdards are emerging for document fbmats that will make it possible to eas- ily integrate statistical information into sophisticated document processing packages such as phstocomgosition sys- tems. This wlIl dramatically reduce the time for extm&hg f@res from data bases for Stpithtioal pwblieaths leading to the &somination of more up-to-date information.

A pilot project in the ITU, h o w as the B1ewh.lmuniation W m x d o n

a &crocomputer of sufficient capaciG can be used for the management of a large telecommunica€ion statistical data base. In addition to the features a v M e within taEe data base; data can easily be extra~ted~fm lure with document prams- sing and statistical analysis tools for pre- senting information and mgkine deu- sbm.

A flexible data base system frees €he tetecommunication expert from data W e m e n t complexities allowing him to con~entmte on analysis. This increases productivity and quality by providing him with more time to refine models and produce more accurate plans and forecasts.

The new generation of microcomputer opergtbg systems, data base manage- meat systems as well as analysis and pre- sentation software tools will allow more sophisticated appliwti~m to be devel- oped for telecommunication sWst!cal data bas=, This wiil c e M y imp~ove the u w inhdwe thus providing eonsis- temeg aad trmsparency between applica- kns.

Vea Ba D~IIWJ gmduated from the Ecolepoly- teckniquefZdttrsZe de Lmrsanne witli a doctor- ate degree in e&eerin& spsiW&g in the subject of stochastic proems in nuelear engineering. He began his non-academic career by computerizing the cost of living index, population &&istics and tax sWstics for the Geneva State (S&tzerEan&) wbere he developed an origin& technique to forecast State tax income, ffe &so worked as a com- puter consultant to design and iqiernent an accounting p a w e for a brokerage h Since October 1981, he has been with the Computer Deplldtment of the PI"U where he now hoMs tb position of Deputy Chief. In March 1988, hc was &ssigneda task of design- ing a data base for the RASCOM project.

MdBrret Mhgm graduated from the George Wkshhgton University with an M3A in iafor- mtiinsystems technology. Ift! spent 11 yem with the fn&~rnational Monetary Fund d d - oping and suppmthg large ststistical data Lwe$ t a t storage and retrieval .systems and networked workstation appEimtioos. S&ce June EBB, he bas been with the Cmputer m m e n t of the ITU 6ve1oping an infor- mation system for the WCOhrl project.

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