Geo-Referencing Brazilian Public Telephones

Geo-Referencing Brazilian Public Telephones

Geovane Cayres Magalhaes
CPqD Telecom and IT Solutions Rod. Campinas MogiMirim km 118,5
13083-350 CAMPINAS SP Brazil

Enaldo Montanha
Fundacao Paulista de Tecnologia e Educacao
Av. Nicolau Zarvos, 1925 16401-301 LINS SP Brazil

Abstract
Brazilian fixed line telecom operators have met the goal of having installed their pay phones for public access so that no citizen living in a locality of more than 300 inhabitants must walk more than 300 meters to reach a pay phone. Proving to ANATEL, the Brazilian regulatory agency, that this had been accomplished involving many geospatial services, including GPS, field survey, GIS, and Internet deployment of geographical queries. Brazil now has almost 1.5 million pay phones, all of them geo-referenced.

Introduction
The Government can play a major role in deploying large national mapping projects. Several of these projects are carried out by national agencies that have a specific mission to provide certain types of mapping infrastructure. This is the case of the TIGER files provided by the US Census Bureau.

In this paper we will describe another way that governments can, indirectly, foster national mapping projects. To fulfill a specific government regulation, Brazilian telephone companies had to perform a big task: build a national map of Brazil showing localities of greater than 300 inhabitants and the proper placement of their public access pay phones (TUP). It helped the telecom operators to thus map their concession area and to geo-reference and distribute about 1.5 million pay phones.

The regulations set the goal that the telephone companies had to meet to be compliant with ANATEL, the Brazilian telecommunications regulatory agency. One of the key goals achieved was that no citizen living in a locality of more than 300 inhabitants should have to walk more than 300 meters to reach a pay phone. Brazil is now one of the countries with the most pay phones per inhabitant, with a high degree of distribution reaching all citizens. Some of the activities that had to be performed to achieve this included: the processing of satellite images, field surveys with GPS, the application of geo-coding techniques, the use of applications to select the best distribution of pay phones, the coordination of thousands of workers, and the remote distribution of management systems.

Some regions had good quality maps. For those regions, it was sometimes possible to georeference public telephones by address interpolation. Another option was the direct placement over the map of the result of field surveying. In areas with maps with some precision and no address reference, rubber sheeting was employed to adjust the map so that the GPS field survey could be used. In other areas, satellite images plus GPS field survey for placement of pay phones and street centerline acquisition proved to be effective. This required an enormous amount of work and the logistics were very complex.

Goals to be Met
In 1998,the Brazilian government established rules for the privatization of the national telecommunications system. Before privatization, the system was comprised of a holding company, TELEBRAS, and 28 other companies. A regulatory agency, ANATEL, was created. For fixed telephony, the country was divided into five concession areas. Three main, large areas composed of several states, and two remaining small municipal areas. A concession was sold to an incumbent telecommunications company (TELCO) for each of these areas. These concessions inherited the infrastructure already in place. For the main areas, three other concessions were sold to “mirror” competing companies. For cellular telephony, other concession areas were set. For long distance operations one incumbent and one “mirror” concession were set for the whole country. More information on the concessions and Brazilian telecommunications regulation can be found at www.anatel.gov.br.

Of specific interest in this paper is Law # 2.592, dated May 15, 1998. This applies to the five incumbent telecommunications companies only. The plan is aimed at making basic telecommunications services available to all Brazilians regardless of their social class or place of residence. It established a number of goals to be met. However, for the sake of simplicity, we will summarize the goals to be met by each incumbent which require some form of geospatial information technology (GIT) and services:

To provide services to each locality of more than 300 inhabitants, by the end of the year 2005;
No one, living in a locality, should walk more than 300 meters to reach a pay phone (TUP), by the end of year 2003;
To activate a certain number of TUP, by state, totaling close to one million by the end of the year 2001;
To increase the density of TUP to at least 8.0 TUP / 1000 inhabitants and 3% of the total access lines installed, by the end of year 2005. This goal should consider the spatial distribution of 3 TUP per 1000 inhabitants, even for precariously urbanized areas;
To activate TUP in all regular schools and health institutions within one week of the request for service, by the end of 2003;
To activate at least one full service TUP for localities greater than 100 inhabitants which do not have local telecommunications services by the end of the year 2005 (for localities with no telecommunications services located more than 30 km from any locality with local services, the obligation to serve it was given to the incumbent long distance telecommunications company);
To establish point of sales not far from the TUP. Other peculiarities concerning the types of TUP and the services they allow are omitted here for simplicity’s sake. Complete information can be obtained from the ANATEL Web site.

The concessions were sold at the end of July 1998, and there were partial goals to be met. However, only the final goals are described herein because there was a clause stating that if a company met their goals early and by the end of year 2001, they would be able to leave their area in order to compete with the other incumbent and mirror companies. All the TELCOS attempted to do this, and so 2001 was a very busy year.

Mapping
Brazil has a population of about 150 million and covers approximately 8.5 million square meters of land (larger than the USA not including Alaska). The first problem the TELCOS had to face was the identification of the localities. Localities were defined to be as little as an agglomeration of buildings with some stable inhabitants. In certain regions, the identification of small localities is quite simple due to the availability of precise maps. But there are also huge geographic areas with dense vegetation, and even if good maps were available, the identification of small localities would be quite difficult. Reasonable maps were available showing the municipalities (equivalent to the US county) boundaries, roads and highways, and states boundaries. Other maps showed specific locality boundaries that had to be adjusted to properly fit into the overall concession map.

Ideally, meter resolution maps would have been used, but this was not feasible for the entire country. Landsat images were used for almost every purpose: to identify urban footprints, to georeference and rubber-sheet locality maps with problems, to serve as background for boundaries and objects geo-referenced by several means, and so on. To properly manage the locations of TUP, localities needed to be represented by street centerlines. This way, dead spaces (non-populated areas) not identified by satellite images would appear. However, in very small localities, a few TUP would cover the entire area, including the dead spaces. Thus, it was also necessary to map street centerlines. A wide variety of land-base maps were used.

Field Surveying
In addition to the maps, it was necessary to properly geo-reference TUP, regular schools and health institutions. Computerized records existed with this basic information on TUP, and regular school and health institution address databases were also available. Normally, this type of information would reside in a computer mainframe database. However, complex logistics were needed to manage the massive amount of changes. For instance, the number of TUP grew from about 600,000 in 1998 to more than 1.5 million today. Most of this growth occurred in 2001. TUP are not meant to generate profits. In some places, such as shopping centers, TUP are heavily used and they are well protected from vandalism. In other areas, TUP are difficult to maintain, but they play an important role in the region. TUP, in Brazil, use an inductive card technology that provides proof of payment and are remotely supervised for accounting and malfunctioning purposes. Several techniques can be used to survey TUP:

Field surveying with GPS techniques
Address interpolation using the TUP address
Surveying the TUP and positioning it over a paper map for future digitalization

In the field, surveyors had to collect not only the coordinates of TUP placement but also information on its type and features. The data collected included: address, infrastructure, 24-hour availability, shelter type, access line identification, serial number, phone number, ability to receive calls, accessibility, make/model, etc.

We estimate that the size of the survey crew exceeded 1,000. The TELCO managers and subcontractors have a wealth of fascinating stories to tell about survey crew experiences. One can imagine what could happen when surveying in slums, forests, during rainstorms, etc. At one point, there was simply not enough precision GPS equipment available to equip all surveyors. GIT Each TELCO needed an AM/FM/GIS system to help manage this complex project. Spatial databases were determined by region, but due to the administrative division of the concession area, generally several of these regions had to be joined to allow for sophisticated queries and algorithms making up the very large databases. However, in all cases, switching from one database to another would have to be done within the same user session.

This is the basic mapping scenario:

Division boundaries of the states inside the concession area
Highways, roads, hydrography
Division boundaries of the municipalities (counties) and their important features
Division boundaries of the urban areas (localities) and their important features
Aerial photos from diverse sources and different levels of precision
Street centerlines and underline addressing databases
Regular schools, health institutions
TUP and TUP inductive card point of sales
Other desirable objects input according to availability

As mentioned before, the TUP-MS required a high degree of availability, distribution over a wide area network, and very important, usability. System management required use of Internet access for ease of software deployment and maintainability. The use of modern GIT technology, such as image compression, GPS, and graphic web access, were stretched to their limit. As the maps were being readied, the already installed TUP had to be surveyed and properly placed over them. This task required the use of several data conversion techniques. If a region had good maps, with street centerlines, address ranges, and so on, an interpolation technique could be used. This technique would get the TUP address from a conventional database and, depending on the information available for the street centerlines, would interpolate the geographic coordinates of the TUP placement inserting into the database the complete information.

Imagine a database holding a complete map of the Sao Paulo city and surroundings (most of the time, precise to the point of having each specific address geo-referenced) with its 10 million inhabitants, including homes and office buildings. Now, imagine inserting by interpolation more than 100,000 TUP. Then imagine having to do this more than once to accommodate updates and adjustments. The algorithm would assume that there was a match for the TUP address in the database. The TUP, normally, is placed in front of a regular address. If the maps were good enough, this address would be already geo-referenced. If there was no match, the algorithm would try to find the two addresses closest to the TUP address, on the same side of the street, to get proper interpolation. This process would then try a series of situations until an interpolation could be calculated even if there were no range addresses in the street segment. Of course, the first attempt would verify if the street existed in the spatial database. In this case, and for the other special cases, a detailed report was generated.

Another way to geo-reference the TUP was to get the TUP coordinates directly from GPS devices. In this case, the information would be entered directly without the need for interpolation. However, due to poor map precision, checks for closeness to street segments and coordinates adjustments had to be performed. Still, another way to get the coordinates would be to geo-reference the TUP position on top of a paper map and then obtain the coordinates with the help of digitizing tablets. After positioning the already installed TUP, and putting in place the update process for on-going activities, the next step was to develop an optimizing algorithm to find the near optimal spots to install the new TUP (or to move TUP positions) to comply with the regulation. Let us assume that the optimal spots were identified for a given area. If the area had good maps, plotting the proposed spots over the detailed map would be enough for the installation crew. The installers would return the maps, and additional information on the TUP installed, to be processed.

In fact, however, this process is quite complex, since it required integration with the legacy work order systems already in use by the TELCOS. If the area had no street maps, the proposed spot coordinates had to be transferred to GPS devices to help the installers. Several times, a proposed spot would fall in a dead space (green areas, water reservoirs, etc) requiring special input and new algorithm iterations to account for these situations. One of the TELCOS mastered this technique to the extent that installers would find a solution, most of the time, in two iterations. The algorithm for finding the near optimal spots for new TUP placements depends on the method used to verify the goals. Remember the main goal was to have no user walk more than 300 meters to reach a TUP. A few techniques were used:

From each TUP, paint the street segments paths up to 300 meters from the TUP. Then, collect the street segments that were left partially or totally unpainted. This method required the existence of very good street maps (and topological network) and was rarely used;
From each TUP, paint a radius smaller than 300 meters (to account for walkers having to get around the street blocks). Then, collect the areas not painted;
Divide the area in sub-regions (squares, hexagons, etc.) of empirically determined sizes and identify which sub-regions do not contain at least one TUP;

The verification algorithms identify areas of non-compliance. These areas were then analyzed to determine near optimal placements of TUP. In some cases, compliance was achieved by manually determining new TUP placements. Surveyors would walk in the area to find good installation spots and then back in the office they would make the final adjustments and, in a second visit, perform the appropriate changes. The placement algorithms were very complex and required a lot of testing and trials.

To be complete, the TUP-MS had to provide thematic mapping so the users could graphically report on TUP features and get a spatial feeling on how they could comply with the regulation most economically. ANATEL auditors also needed to be sure that the TELCO installed the TUP according to the rules.

Operations
There were other goals to be met by the TELCOS that made the TUP challenge even more complex. In addition to being operational, a TUP needs to be part of the telecommunications network. Installing and making a TUP operational in remote areas is very time- consuming and expensive. And the TUP equipment manufacturers were very busy trying to keep up with the high demand for units. Once all the incumbents started trying to beat the goals and qualify to compete in other areas, each TELCO had to lay networks and provide access as soon as possible before the end of 2001. Then, if another TELCO attempted to compete, they would have already taken the majority of customers. During this period, there was simply not enough telecommunications cable available to satisfy the needs of all the TELCOs.

Each TELCO set up project teams responsible for the work needed to satisfy the goals that reported directly to the VP level. Practically the entire geo-processing industry of Brazil, directly or indirectly, participated in the effort. The activities in the area in 2001 were so over-whelming that 2002 by comparison seemed to be a very slow year.

Figure 1 is a map of Brazil with the concession areas and corresponding incumbent TELCOs. Figure 2 is a photo of the most common infrastructure for installing pay phone (TUP) equipment. Its ear shape led Brazilians to nick name the pay phones “Big Ears”. Figure 3 shows a sample pay phone unit. The inductive phone card is inserted in the slot situated at the bottom right side of the phone unit.

To give an idea of the amount of work done, it is necessary to understand that just the area of Brasil Telecom comprises the Federal District plus nine states, extending 2.8 million square meters, of which 30 thousand square miles are urbanized. Around 7,900 localities in 1,860 municipalities were identified. Approximately 41 million people live in the area, of whom about 11 million have telephone access. Almost 300,000 TUP are in operation. The area of Telefonica is even more densely populated. It comprises the state of Sao Paulo only, but has almost the same number of inhabitants as the area of Brasil Telecom. The number of TUP installed is also about 300,000. In Telefonica’s area there are more than 14 million access lines in operation. If we add the numbers of Telemar, CTBC Telecom and SERCOMTEL, these figures double. ANATEL’s site referenced at the beginning of this paper has links to pages that update these numbers monthly.

Conclusions
We briefly describe the activities of five large AM/FM/GIS projects fostered by a government program that formed part of the privatization of the Brazilian telecommunications system. These large projects required the use of sophisticated GIT and related services. In addition to fulfilling their primary objectives, these projects also helped in the assessment of maps, introduction of technologies, and in the professional development of many people and organizations in the telecommunications sector.

Acknowlegements
We would like to thank to Evando Natal from Brazil Telecom and Joao Bonfa of Telefonica for their valuable information regarding the projects in their companies. They, other TELCO managers, their managers and colleagues, and all subcontractors survived a fantastic experience and helped their companies and Brazil successfully conclude a world-class effort. We would also to thank our Companies for their support. CTGEO, the geo-processing center of Fundação Paulista de Tecnologia e Educação, played an important role by doing a large portion of the data conversion work and field surveys. CPqD, a non-profit R&D Center, previously part of the TELEBRAS System, served as the prime subcontractor for more than 80% of the effort. CPqD also provided the main TUP-MS that performed the work. CPqD also created the inductive card and the corresponding equipment technology. Thanks to all of our colleagues who played a role in these projects.