Vulnerability of the Cellular Telecommunication Network in the

Vulnerability of the Cellular TelecommunicationNetwork in the Lower Mainland

British Columbia

Produced by A. Andre, A. Glen, J. Good, J. Gutsell, I. Hayat,J. Kershaw, J.Miller, J. Nash, T. RelkoffGeography 452, Advanced Issues in Geographical Information SystemsDepartment of Geography, Simon Fraser UniversityMarch 17, 2000

The Vulnerability of the Telecommunications Network in the Lower Mainland

1

Introduction

An understanding of the vulnerability of the cellular communications network iscrucial in hazard prediction and response management efforts. Increasing dependence oncellular infrastructure is rapidly outpacing knowledge of the potential weaknesses of cellularnetworks. A large and increasing portion of the population rely on the network for personaland business communication; an increasing number of emergency response personnel arebecoming dependent on the network. Hazardous events and response are typically analysedin spatial dimensions, and Geographic Information Systems provide a means of furtherinvestigation into this problem.

The Centre for Policy Research on Science and Technology (CPROST) hasattempted to assess the vulnerability of Canadian wireless networks in natural hazards, andto further assess the resulting implications for delivery of emergency telecommunicationsservices. The aim of this project was to analysis the spatial component of CPROSTs’research. Results from the spatial analysis will be integrated into the outcome of theCPROST project.

Natural disasters are responsible for massive disruption to the population andinfrastructure. The Lower Mainland is located in an area where multiple hazards are present.Earthquakes have the greatest potential to cause major social and physical disruptions in thisarea. This proposal presents a method of evaluating the magnitude of this hazard, a meansof predicting the associated social impacts, and a solution to evaluating the vulnerability ofthe communications network in the aftermath of an event.

The scope of the project was limited to the cities of Richmond and NorthVancouver. The use of the full GRVD would have been too extensive and time consumingto complete a thorough analysis. Therefore the scope was restricted to the two localities sothat a more in depth analysis could be undertaken. Richmond was chosen because the regionis most susceptible to the effects on an earthquake and secondary effects such as liquefactionand flooding. North Vancouver was selected because it is one of the more stable regionswithin the GRVD and therefore might provide a control area for use in this study.

Background

Few cell phone users worry about how a natural disaster, i.e. earthquake, wouldaffect phone service. If a disaster were to occur would the network remain intact? Could thenetwork handle a sudden influx of users after an earthquake? Would emergency responsepersonnel be able to access the network? The following examples demonstrate thevulnerability of communication networks:

In January of 1998 a devastating ice storm hit Quebec and Ontario. However, thecellular service was not greatly affected by this situation. Towers lost power but they weremaintained using back-up generators. On September 21st, 1999 a 7.3-magnitude earthquakehit Taiwan. This event knocked out the country’s fixed line telecommunications network.Roads, rail and power infrastructure were disabled, 4000 cell towers were rendered useless bythe event. Nearly all of Taiwan's 3.7 million cellular customers were deprived of service.


2

Also, in September 1999 a 5.9 magnitude earthquake hit Athens Greece. After the shakingpeople tried in vain to make calls on overcrowded cell networks.

Potential Hazards and Impacts

Physical Hazards

The effects of an earthquake are most damaging on surficial glacial sediments.Unconsolidated surficial sediments, such as the sands and silts that are present in Richmondand Delta, tend to amplify the effects of an earthquake. These areas are also susceptible toliquefaction, a process that involves loss of cohesive strength between saturated sediments,causing them to act like fluids.

The magnitude of damage that would result from a large mega-earthquake in themetropolitan Vancouver area is hard to estimate, but it is almost certain that older sectionsof Vancouver, such as Gastown, would suffer massive devastation as construction occurredthere prior to the establishment of earthquake resistance building codes. Primary effectswould include toppling of buildings, damage to roads, and disruption of telecommunicationnetworks. Secondary effects would include fires, floods, chemical contamination inindustrial areas, and rockslides occurring due to decreased slope stability.

Hazard Response

Earthquakes can damage transportation routes, power transmission systems,communications systems, sewer systems, water supplies, medical facilities, and residential,commercial and industrial buildings. The extent of the infrastructure damage depends on thedesign and engineering of the structures and the magnitude of the hazard. Thetransportation and communication infrastructure are essential to the coordination of therelief effort that occurs after the hazardous event. Telecommunications systems rely on thefunctionality of the power transmission systems. If the power transmission infrastructurehas been damaged significantly, the communications network would suffer. Cellular towerstypically have limited back-up power. When this back-up power is depleted, the towerbecomes non-operational and efforts to repair the towers may be hampered by damage totransportation systems. This results in an increase in demand per tower.

Social impacts include both immediate and delayed effects. Immediate impactsinclude injuries, fatalities, panic, and confusion. Individuals are immediately concerned withpersonal safety and rescue of those nearby. This is typically followed by emergencyresponse, assessment of building safety and movement of people to emergency responsecentres. Emergency response centres include schools, community centres, recreationfacilities, malls, and churches. Injured individuals should be transported to medical facilities;the efficiency of the rescue effort will depend on the damage to the infrastructure, themagnitude of the hazard and the organization of response personnel.

These responses will result in large changes to the population density distribution.The population distribution before the hazard will depend on the time of day that the hazardoccurs. People congregate during working hours whereas the population is more evenly


3

distributed in non-working hours. Convergence to emergency response centres would createincreased population densities in areas where the infrastructure was least impacted. Thiswould result in taxation of the remaining infrastructure in these areas (communicationnetworks, water supplies, medical facilities).

Cellular Technology

The cellular communication market is divided in two ways. The market is divided bycarrier (available carriers are Fido, ClearNET, Cantel and Telus), and by frequency (analogand digital communication). Analog technology transmits a communication signal, which isamplified and sent in analog format from the transmitting antenna to the receiving antenna.Digital technology transfers analog signals into a binary code and then transmits them to thetower. Cell phones work by creating a link between the phone and an available tower. Thephone searches for the tower with the strongest signal (the closest tower). The phone thenwaits for permission to use that tower. Permission may not be granted if the capacity of thattower is reached. In this case, the phone searches for the next strongest signal within rangeand again attempts to access it.

Figure 1: Analog and digital transmission signals (Wireless Communications Facilities Issues Paper,1995)

The industry also allows for roaming, a method which allows a phone from one carrier toaccess another carriers network. This occurs in the event that the registered network is full.

Modeling Hazards and Impacts

Physical Hazards

Modeling physical hazards in a GIS requires an algorithmic approximation of theactual hazard that occurs. Modeling is based on human understanding of physical hazardsand requires several approximations and assumptions to be made. Actual hazard predictionis difficult to quantify, but various scenarios can be evaluated to gain an understanding ofimpacts during potential hazards.

Nhematis, designed by Nobility Software Inc, is a natural hazard electronic map andassessment tool, information system. It is able to centralize, automate, collect, represent andanalyse natural hazard information. Its database is an accumulation of data from local,provincial and national sources that includes information on airports, land-use, bridges,roads and buildings. Nhematis software assesses risk and vulnerability in various locationsthroughout Canada. In order to determine, and model, the amount of damage, the ModifiedMercalli Index (MMI) was used. This is a subjective scale consisting of twelve categories; ahigher MMI value representing greater earthquake intensity.


4

Infrastructure Damage

Building Material MMI ClassificationSteel Can withstand a MMI value of 8, above 8 the structure is destroyedBrick Can withstand a MMI value of 7, over 7 the structure is destroyedWood Can withstand a MMI value of 9, above 9 the structure is destroyed.

Table 1: Classification of building class vulnerability with MMI values.

Damage to building structure is dependent upon construction materials, buildingcodes, and the magnitude of the hazard. Nhematis will be used to determine the magnitudeof the earthquake and damage will be dependant on that suggested by the Modified MercalliIndex Scale (Nhematis Training Manual, 1999). The information was based on theNhematis user manual.

Methodology

The aim of the project was to model the cellular network and simulate the networksresponse to a natural hazard. The modeling process involved several stages, which werewritten in Avenue, the scripting language of ArcView. Telecommunications companies arebeginning to realize the potential use of GIS for modeling their networks. For example,Vodafone Ltd used GIS to plan their cellular phone networks by overlaying their cellnetwork with demographic information, (Fry, 1999).

Stage 1: Tower Locations

The first step involved the determination of the location of telecommunicationsinfrastructure. Cell tower locations were obtained from Industry Canada's website.Additional information regarding tower locations was obtained through personalcommunication with Mr. Steve Romaine (who compiled maps locating cellular towerlocations for the GVRD). This data was combined with Industry Canada's records toproduce a comprehensive database of both digital and analog tower locations, which wasused as a model of telecommunication infrastructure. For a more detailed explanation of thecontents of this database, (Appendix 1 - Data Dictionary).

This database contained locations for individual antennae. In some areas, there weremultiple antennae on one tower. To simplify the analysis, the capacities for multipleantennae on one tower were summed to one value for the whole tower.

Stage 2: Incorporating Disaster Scenarios

The disaster determines which towers are standing, and which are unusable. Afterthe disaster occurs, the ability of the network to function will be hampered by the loss ofsome towers. The purpose of the model was to determine the functionality of the networkunder such circumstances.


5

The towers left standing were determined using Nhematis. Three MMI coverageswere calculated; the modified Mercalli Index is a subjective index based on the individuals'impression of the event. The coverage consists of concentric circles corresponding todecreasing levels of expected damage. These concentric values have a different MMI valuescalculated by geology, distance from earthquake and soil type. The Modified Mercalli Index(MMI) is used to evaluate damage sustained by structures, (see Appendix 2 – Map 3).

All towers were assigned a MMI threshold value because of a lack of availableinformation on structural integrity (Table 2). Towers within a building class region areassumed to be located on buildings and therefore assume the MMI vulnerability of the class.

Building Class Vulnerability to seismic shaking(MMI)

A 7 or greaterB 8 or greaterC 10 or greater.

Table 2: Nhematis’ Vancouver database with three building classes: A, B, and C.

The MMI maps show values for all regions of the GVRD. Any structure that has alower threshold than the MMI value for that location will be destroyed. For example, abuilding with a threshold of 8 will be destroyed if it is located on an area of the MMI mapwith a MMI value of 9.

Stage 3: Diurnal migration patterns

During the evening the population is dispersed throughout residential areas.Conversely during the day, populations tend to cluster downtown and in other urban areas.The network is used differently at different times of the day, and different days of the week.In order to model the network during various times, the movement of people must also bemodelled. To model this movement, traffic flow data was used in conjunction with censustract data.

The 1996 Census data was obtained from the research data library at Simon FraserUniversity. The traffic flow information was obtained from Greater Vancouver TransitAuthority (GVTA). The GVTA data contains the number of cars and transit passengerscrossing travelling between street network nodes in the Lower Mainland during one hour ofthe morning rush hour (7:30-8:30am). A diurnal population change can be developed fromthis data.

Traffic flow data from the GVTA was depicted as a network of nodes located bytheir latitude and longitude. The nodes contain in and out attributes, referring to the amountof incoming and out-flowing traffic through that node. The GVTA coverage was positionedovertop the census tract. A script was designed to look at all lines that intersect each censustract. The difference between the "in" values and "out" values yields the change in thepopulation for that tract. The "change" value is then added to the total population,providing a revised population at this time.


6

#

#

#

#

#

#

#

###

#

###

#

####

############

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

##

##

##

#

#

#

#

#

#

##

#

#

##

###

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

## #

#

#

#

#

#

#

#

#

#

#

#

#

##

#

#

#

#

#

#

#

##################

#

#

# #

#

##

##

#

#

####

#

#

##

#

#

###

###

#

#

###

##

##

##

#

####

#

######################################################

#

#

#

##

#

#

#

#

#

#

#

##

#

#

#

#

#

#

#

#

#

#

#

##

#

#

#

#

#

#

#

#

##

#

##

#

#

#

##

##

##

#

#

#

#

#

#

##

##

#

#

#

##

#

##

#

#

#

#

#

#

# ##

#

## ###

###########

###

### #

## #

## # #

##

# ###

###

##

##

# ##

#

## ##

#

##

#

##

######

###

###

# ##

###

#

#

#

# #

## ###

#

#

#

####

#

#

#

#

#

###

#

#

#

##

#

#

##

##

#

#

#

#

##

##

# ##

##

#

##

##

###

##

##

#

#

#

#

####

#

#

####

#

#

#

#

#

#

#

##

#

#

#

#

#

#

#

##

#

### #

#

## ### ##

#

#

#

#

#

###

# # #

#

###

#

####

###

## ##

# ####

#

#

#

##

#

##

#

#

#

#

#

#

#

##

#

#

#

##

###

#

#

#

###

###

##

#

#

#

#

#### #

## ###

# #

##

##

#

###

#

#

# ## ###

#

#####

######

#

##

#

#

# #

##

##

#

#

#

#

##

#

##

#

####

##

#

##

####

###

##

#

##

###

#

##

#

###

##

# #

##

#

#

#

#

# #

##

###

#

#

##

#

##

##

#######

#

#

#

###

#

###

#

##

#

#

##

#

# #

#

#

#

#

#

#

#

#

#

#

###### #

###

###

###

#######

######

##

###

##

#

###

###

######

##

#

#

##

#

##

#

#

#

##

###

########

##########

#######

##

#

##

#

#

# ##

# #

##

#

## #

##

#

#

####

##

#

##

#

## #

####

#

#

##### ##### #### # #

#

#

##

#

#

#

##

##

# #

##

##

##

#

#

#

##

#

###

###

## #

#

##

#

###

## #

#

#

##

#

#

#

#

##

##

##

#

#

# # ####

###

# ####

### #

####

###

##

#

##

### #

##########

## ### ### ####

## #

###

##### #

##

### ### #

#

##

#

#

# ##

## #

#

#

###

#

###

#

#######

##

##

### ## ##

# # ##

#########

## ##

#

## ##

### #

#

#

# ### #

#####

###

#

##

# ##

#

##

###

#

#

##

##

#

###

##

###

##

#

#

#

#

##

###

##### ## ####

####### ##

##

# ##

##

#

#

###

##

#

###

# # ## # ##

### # ## ##### ##

##

## ### # #####

## ####

###

##

## ## # # ###

###

####

### # #######

#####

# ###

####

#####

######

###

##

#

####

#

# ##

##

##

###### #

## # #####

##

## ###

###

#

#

#

#

####

#####

##### ###

## #

##

###

##

# ##

#

#

#

#

#

#

##

#

#

#

###

#

##

# ##

#

#

#

###

##

####

#

##

#

#

#

####

#

#

#

#

#

#

#

##

##

##

##

###

### ##

###

## ## #

##

##

###

# ###

#

####

###

##

#

##

#

#

###### #

#

###

# ##

##

#

##

# ##

#

#

###

##

## ###

###

#

## ##

##

##

####

# #

#

# #####

#

##

#

##

# ####

#

## # #

##

###

####### #

###

## #

#

#

##

#

#

#

#

#

#

##

##

#

#

##

## ### ##

##

#

##### ##

##

##

#

#

##

##

##

##

#

#

##

#

#

#

#

#

### ####

#

#

#

###

#

#

##

##

#

#

#

#

#

#

#

#

#

#

##

##

###

##

###

###

# ###

##

## ##

###

#

###

#

##

###

#

#####

##

## ##

#

#

#

###

##

#

###

#

##

###### #

#

#

#

#

# #

##

###

#

###

##

######

# #### ##

#

###

# #

###

##

#

#

#

###

# #

##

####

#

# #

##

# ### ##

# ##

##

# #

#

#

# ### #

## #

#

##

##

##

###

#### ###

###

#

#

##

#

#

###

# #

###

##

####

####

##

### #

#

# #

######

##

#####

#

##

#

### ####

# ##

##

#

#

#

# ###

#

#

###

#

#

#

##

###

#

#

####

#

##

#

#####

########

#

###

# #

# ##

#

#

#

###

#

### # ###

###

## #

##

####

###

##

##### ##

####

####

#

#

#

##

##

# ##

## ##

##

## # ###

#

##

# #### ##

#

#

##

##

##

####

#

##

#

#

#

####### #

###

###

## ##

## ###

# ####

##

#

##

###

###

##

#

#

##

#

###

###

####

#

#

####

### ##

##

#

# ##

#

###

#

##

##

#

#

####

###

####

##

#

#

#

###

#

#

# #

#

#

##

#

#

#

###

######

#

##

# ##

##

#

##

#

# ###

# ###### ###

#

####

#

#

##

#

####

#

###

###

#

#

#

##

#

# ##

# #

#

# #

##

##

#

#

#

## #

###

#

# #

#

###

##

#

##

##

###

#

#

##

#

#

#

#

##

##

#

#

##

#

#

#

#

#

##

## ##

#

##

#

#

### #

##

##

##

##

###

#

#

#

###

# #

#

##

#

#

##

##

#

#

#

#

#

##

#

#

#

#

#

#

#

#

##

#

#

#

#

#

###

#

##

###########

##

#

## #

###

##

##

##

#

###

#

##

###

#

### #

###

# #

##

## #

#

# #

##

#

##

#

####

## #

##

## #

#

####

###

#

###

#

#####

##

###

###

#

######

#

# ##

#

###

##

##

##

###

###

###

####

#

##

####

#

##

#

# ##

##

#

##

##

#

#

#

#

## ##

##

##

####

##

###### #

###

#

#

##

##

#

##

#

##

#

#

####

#

## #

## #

#

###

##

#

#

##

#

###

#

###

#

#

#

# ##

## ### ##

#

#

###

#

#

####

##

#####

#

#

#

# #

#

#

#

#

#

#

#

#

#

#

###

#

#

#

#

#

###

#

#

#

#

#### ###

##

#### ##

#

#

#

#

##

#

#

#

#

##

#

##

##

#

#

#

#

#

#

#

##

##

##

###

### ##

#

#

#

#

#

#

#

##

### ### #

#

# ### ##

#

#

#

###

###

#

#

##

#

#

#

#

##

#

##

#

#

# ##

##

##

#

##

##

# ##

##

## #

#

#

##

#

#

#

#

##

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

###

#

#

##

##

##

#

#

#

##

#

#

#

#

# #

#

###

###

#

#

#

#

#

#

#

##

##

#

##

#

###

#

#

#

##

#

##

#

###

##

##

##

# ##

#

#

# ##

##

#

#

#

#

#

##

##

#

#

#

#

#

#

##

#

#

##

#

#

#

#

##

#

##

#

#

#

#

##

#

#

##

##

### ##

#

##

#

#

##

#

##

#

#

#

### #

#

##

#

#

##

#

#

#

#

#

##

# #

##

###

###

#

#

##

##

#

###

#

###

####

##

#

###

####

#

##

#

###

#

#

#

#

#

#

#

#

#

##

##

#

###

##

##

#

#

#

#

#

# #

#

#

#

##

##

###

## ## ###

##

##

##

#

#

#

#

# ###

##

#

#

#

#

# #

#

##

#

##

#

#

#

##

#

#

#

#

#

#

## #

# ## ######

# #

#

#### ##

###

###

###

####

## ##

#

#

# #

#

##

#

#

##

##

#

#

#

#

#

#

#

#

#

#

#

#

###

###

#

#

#####

#

#

###

#

##

#

#

#

#

#

#

#

##

#

##

##

#

#

###

# #####

#

## #

#

#

## # ## ##

## ###

## #

##

#

# #

##

###

###

#

#

#

##

#

#

#

#

##

## #

###

#

#

#######

##### #

## ## # ##

##

#

####

#

##

#

# #

#

# #

#

# ###

#

##

#

#

#

#

#

##

#

#

## #

##

#

###

##

# # #

###

##

## ##

#

#

#

##

##

#

##

### ##

####

##

##

##

####

##

##

###

#

# ###

#

###

###

#

#

#

##

#

#

#

#

##

#

##

#

#

# ## #

##

###

#

#

##

#

# ##

##

#####

#

#

#

######

#

# ##

#

#

#

#

##

#

##### #

####

## ##

####

##

##

# #

#

## ## #

# ##

##

#

##

###

#

#

##

#

#

#

#

#

#

# #

##

#

##

####### #######

#

#

#

#

#

#

##

##

##

##

#

#

#

##

#

#

##

#

# ###

#

#

#

##

#

##

#

#

#

#

##

#

#

##

#

##

##

##

#

#

#

#

##

##

#

#

# ##

#

##

#

#

#

#

##

##

#

#

#####

#### #####

#######

#####

#########

##

#

#

## ##

#############

#

###

###### ### #############

####

##

#

#

#

###

### #

##

#

#

# #

###

#

##

#

#

##

#

#

#

###

#

## ############

####

##

#

#

#

#

##

###

##

#

#

##

#

##

#

###

##

#########

###

##

####

##

################## #########

#

#

#

#

#

#

#

#

#

#

#

##

##

### #

### ##

####################################

##

#

## #

#

#

#

##

# ##

#

#

##

##

#

#

#

# #

####

##

#

#

#

##

#

#

#

#

#

#

#

# #

#

#

#

#

#

#

#

#

##

#

#

##

##

#

###

#

##

##

# #

# ##

##

#

##

#

#

#

#

#

#

#

# #

#

#

#

##

# #

#

##

# ####

#

### #

#

####

#

##

#

#

#

##

# #

## ##

# #

#

#

#

##

##

#

#

# ####

##

##

# ##

##

#

#

#

#

#

#

#

###

###

# #

#

#

##

#

#

# # ### ###

# ##### #

##

######

#

##

#

####

#

#

#

#

##

#

# # ## ##

#

Figure 2a: GVRD population distribution during the evening/night (Night time scenario) asproduced by a sub-process of the model.

##

#

##

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

##

#

##

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

##

#

#

#

# #

#

#

#

##

#

#

#

#

#

#

##

##

#

#

#

#

#

#

#

#

#

#

##

####

##

#

#

###

#

#

##

#

#

##

#

#

#

#

#

#

#

#

#

#

#

#

# #

#

#

#

#

#

#

#

#

##

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

##

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

##

##

###

##

##

# ##

#

###

#

####

###

###

#

##

##

##

#

#

###

#####

# ##

##

##

# #

#

#

##

# #

#

#

## #

##

##

#

# #

#

#

#

#

###

#

#

# ####

#####

##

#

##

#

#

#

###

##

# #

##

###

##

#

#

##

##

### #####

##

#

###

#####

#

###

#

#

#

#

#

#

#

#

#

#

#

#

#

##

# ## ##

##

###

# ###

##

#

##

#

#

##

## ## #

####

##

#

###

#

##

#

#

##

#

#

##

#

##

#

##

#

####

## ####### ##### #

######

# ### ## #

##

#

#

#

#

## #

#

#

####

##

#

#

#

#

##

###

##

#####

#

##

#

#

###

#

##

# #

#

#

#

###

##

#

#

##

# #

##

###

#

#

#

##

#

###

## #

#

#

#

##

####

#

###

#

#

#

#

##

# #

#

#

###

#

#

### ###

#

## ##

##

##

#

######

####

#

#

###

### #

####

#

#

##

# ###

##

###

#

#

####

#

## ###

# ##

##

###

###

########

##

###

#

##

##

#

#

#

#

#

#

#

#

##

##

#

#

#

#

##

#

#

#

#

##

# ##

#

#

#

# #

###

#

#####

##

##

#

###

#

#

##

#

#

###

#####

## #

# #

#### #

### #

# ##

#

# ###

###

##

#

##

##

#####

#####

##

###

#

##

#

#

#

#

#

##

###

#

#

#

##

#####

#####

#####

#

##

#

#

##

########

#

#

#

#

#

#

#

#

#

#

# ##

# ######

##

##

#####

#

#

#

#

#

##

#

##

###

# #

##

#

# ####

##

##

####

#

#

##

#####

##

##

#

# # #####

#### #

##

######

# ####

#

#

# #

#

#

##

#

#

###

#

#

#

##

#

##

# ##

#

#

##

##

###

#

##

#

#

###

# #

#

#

###

#

#

#

#

#

#

#

#

#

#

#

##

##

#

##

#

#

#

#

##

#

#

#

#

##

#

#

#

##

#

#

#

#

#

#

##

#

#

#

#

#

#

##

#

#

#

#

#

##

#

#

## #

#

#

#

###

# ##

#

#

###

#

#

#

#

#

###

####

##

##

#

#

#

##

#

# #

##

## ##### ####

######## #

###

## #

##

# #

##

###

#####

#

#

## ## ## # #

##

###

###

##

#### ###### ## ### #

# ###

#

#####

#

#

###

# ####

###

#

#

##

#

##

##

##

# ##

##

# # ##

##

#

#

#

#

##

######

###

##

### # ### #

#

#

# ####

##

# ##

##

#

#

## ##

##

####

##

####

##

#####

###### ### #

###

## ##

##

##

###

### ## ##

# ####

## ####

## ##

###

####

#####

#

# # ##

###

#

############ ######

#####

#### ###

## ###

###### #

### ##

##

#

#########

# #

# ###

#

#

#

# ####

##

##

##

#

##

#

##

###

## ##

# ##

#

###

##

#

## # #

#

#

##

#

#

#

###

##

#

#

#

#

###

##

###

##

#

#

#

#

#

###

#

#

##

#

##

#####

###

###

#

#

#

#

#

##

#

#

#

##

#

##

#

###

#

##

##

# ###

### ###

#

#

#

#

# #

#

#

#

##

####

#

# ####

## ##

##

#

#

### #

#####

##

##

####

#

##

##

##

#### ##

#

# ######

##

#

#

#

# ##

#

###

#

#

#

###

#

#

#

#

#

# ####

#

#

##

#

#

#### #

##

##

##

##

##

#

##

# #

#

#

#

#

## ###

#

####

#

#

#

#

#

##

##

#

#

###

#

##

##

#

# ##

## #

#

###

##

#

#

#

#

#

#

#

##

###

# #

#

#

###

##

# ##

###

###

# #

#

##

#

#

##

##

#

# #

###

###

#

#

##

#

#####

## ###

#

#

#

###

##

#

#

#

##

###### # #

#####

# ##

#

#

#

##

##

##

#

###

#

##

##

##

### ##

#

#

#

#

#

#

##

#

#### #

## #

##

###

#

# ######

#

##

#

#

#

##

#

#

#

##

#

##

#

###

##

###

##

## #

####

##

#

# ### ##

##

## #

##

#

###

#

#

# ###### #

##

### ######

##

###

### ####

## ### #

#

# #

##

#

#

#

#

#

#

# ## ##

##

### #

## ## ##

# ## #

#####

#

##

####

######

#

##

###

##

####

##

#

#

##

##

##

# ##

#

## #

###

# ###

#

#

###

##

# # #

###

###

##

#####

###

#

##

#

##

##

#

## #

###

###

##

##

###

####

##

#

#

#

#

#

##

##

#

#

#

###

## ###

###

### ## ### # #

##

#

######

###

##

##

#

# ###

####

#

#

##

#

##

# ##

####

##

#

## ## #

##

##

#

# #

# ### ##

#

#

#

#

#

###

#

##

#

#

# #

#

#

#

#

#

#

## #

# #

#######

#

##

#

##

#

#

#

#

#

##

#

# ##

#

#

#

#

#

## ####

##

#

#

#

###

#

#

#

#

##

#

####

# #

#

#

#

#

#

#

#

####

###########

##

#

##

#

#####

#

###

#

#

###

#

#

###

#

#

##

#

# ###

#

#

##

#

#

#

# ##

##

#

#

#####

##

## ##

#

###

#

#

# #

#

# #

#

### #

#

##

# ##

#

#

#

#

#

#

#

#

##

#

##

## #####

#

### # #

###

###

#

#

##

##

#

#

##

# ###

#

##

#### #

###

#

##

#

#

#

#

#

##

##### #

### #

##

#

#

## #

##

##

##

#

##

#

#

#

#

#

##

#

#

#

#

###

##

#

#

#

#

#

# ##

##

##

# ## #

#####

## #

###

##

#

#

##

#

##########

####

###

#

#

#

#

#

#

# #

#

#

#

#

#

##

#

#

#

#

#

#

#

#

#

#

#

#

#

##

#

#

##

#

#

#

#

#

#

#

#

##

##

##

#

#

#

#

#

#

#

#

#

#

#

#

##

###

##### #

##

##

##

#

##

#

##

##

#

##

# #

#

###

###

#

#

##

#

###

##

# ###

#

##

#

#

#

##

##

#

###

##

##

#

###

###

# ##

#

##

#

##

#####

#

#

##

#

##

####

##

#

#

#

#

#

#

## ##

#

#####

###

##

#

#

#

#

#

#

#

#

#

#

##

#

#

#

#

#

#

#

#

##

#

#

#

#

#

# #

#

#

#

#

##

# #

#

### ####

##

##

#

#

#

#

# #

#

#

###

#

##

#

##

##

##

#

#

#

#

## #

#

#

##

#######

###

###

##

#

#### ##

##

# ###

#

##

#

### #

#

#

#

##

## ##

#

#

#

#

#

#

#

##

#

#

#

#

#

##

#

##

#

#

##

#

#

#

#

## #

## ##

##

##

####

#

##

#

##

##

##

#

# ## #

##

#

# ##

##

#

##

###

#

# #

#####

#

#

#

#

##

#####

#

#

#

# #

##

##

##

#

##

##

###

#

#

#

#

#

#

#

#

#

#

#

#

#

##

#

#

##

##

#

##

#

#

##

###

#

##

#

#

#

#

#

##

##

#

#

#

#

#

###

#

####

#

#

#

#

#

## ##

###

##

# #

##

## ###

####

# #

##

#

#

#

#

#

#

##

#

#

#

#

#

#

#

#

##

#

##

##

#

#

#

#

#

##

#

#

#

# #

##

#

#

##

#

###

##

#

#

#

#

#

# #

#

#

#

## ##

##

#

#

#

# ####

# # ## #

#

#

###

#

#

##

### #

##

##

###

### #

#

#

#

##

###

###

##

###

##

##

###

#

#

#

#

#

##

##

##

#

#

#

#

#

#

#

#

##

#

### #

#

##### #

###

##

#

#

#

#

#

#

#

#

#

##

#

#

#

#

# ## ###

##

###

###

##

###

## ##

##

#

#

#

#

# #

#

#

#

##

#

#

#

#

###

#

# ###

###

#

###

##

#

# ##

###

##

##

####

##

#

##

##

#

##

#

##

#

## ##

#####

#

#

##

#

# ##

#

#

#

#

#

#

#

#

#

###

#

##

#

#

#

#

#

#

##

#

#

# #

#

##

##

#

##

##

##

#

#

##

#

##

#

##

#

#

#

##

#

#

#

#

#

#

#

#

#

#

# ##

#

## #

#

# ## #

#

##

##

##

#

##

# ##

##

##

##

#

##

# #

#

#

#

##

##

#

#

##

##

#

# ##

#

#

#

##

###

##

##

##

#

##

#

#

#

#

#

#

#

#

#

#

####

##

####

### #

#

#

#

#

#

#

##

## #

#

# #

#### #

##

#

#

#

#

#

#

#

#

## #

#

#

###

###

#

#

#

#

#

#

#

#

#

#

#

#

#

#

# ## #

#

## #

#

#

#

#

##

#

#

#

#

#

#

##

#

#

## ##

#

##

#

####

# #

##

##

#

#

#

#

##

#

##

##

#

#

#

##

#

##

##

#

# #

#

#

#

#

#

#

#

##

#

###

####

#

###

#

##

#

#

##

# #

##

##

#

#### #

# #

###

##

#

####

##

# ###

# #

#

###

#

# ##

### ##

####

#

#

##

#

#

#

#

##

##

#

#

#

#

#

##

#

#

#

##

#

# ##

#

##

##

#

#

## ##

###

#

##

#

#

#

#

#

##

#

#

#

#

#

#

#

#

##

#

#

##

#

##

#

#

#

#

#

#

#

#

#

#

#

##

#

#

#

#

###

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

# #

#

#

#

#

#

##

Figure 2b: GVRD population distribution after the morning rush hour (Daytime scenario).

There are several variables that can be adjusted for the day and night scenarios. Theday scenario is based on cars traveling over certain points for one hour. To accurately assessthe number of people moving during the total rush hour, certain questions must beanswered. What is the average number of people in each car? What percentage of thepeople traveling in the morning, actually commute during the 7:30-8:30am rush? Both ofthese variables can be adjusted to represent a wide range of possible commuting scenarios.

Each dot represents

500 people

Each dot represents

500 people


7

Stage 4: Modeling levels of cell phone usage

Once the modified population of each census tract had been modelled, a populationvalue for cell phone users must be known for the analysis. The model employed severalvariables to determine the number of people making calls the initial time following the event.An accurate number of phone users were not available but a ratio of one in five wasprovided, (Penn, 2000). A variable was needed to identify the number of people attemptingto use their phone immediately following a disaster. This was difficult to quantify, as noprobable value had been determined. The value could range from 1.0 (all cell phones ownedare in operation) to 0.0 (no cell phone owners are making a call).

Several assumptions on cell phone usage must also be stated. The analysis assumesthat all cell phones are available for use, following the disaster. It also assumes that all cellphone users are capable of using their cell phone after a hazardous event. These assumptionswere necessary to develop a workable model.

Stage 5: Visualizing tower access

Once the database was completed, the next step involved the creation of a system todetermine access areas for each cell tower. Access areas are defined as the area around eachcell tower where phone calls are directed. These areas are built on the assumption that a cellphone user accesses the closest tower. Taking these assumptions into account, the easiestway to model the access areas was to use Thiessen Polygons. DeMers defines ThiessenPolygons as, "a method of creating polygons or proximal regions are around point objects bydefining them mathematically, dividing the space between each point, and connecting thesedistances with straight lines". Although this method would show areas closest to each tower,it does not take into consideration the different range values of various towers. If Thiessenpolygons were used, the access area of certain towers may be larger than the range of thattower.

To accommodate this a modified version of Thiessen polygons was implemented,which limits the size of each polygon to a specified range value. A script divided the GVRDinto a modified version of Thiessen polygons, based on the location of cellular towers. Therange of the tower limited each of the Thiessen polygons. A different Thiessen coveragewas created for each range value. Each individual Thiessen coverage was clipped to theThiessen coverage of all towers. The clipped coverages were arranged in descending order,(Appendix 3 – Script 1).


8

#

##

#

#

##

#

##

#

#

#

#

#

#

#

#

#

##

#

#

#

#

#

#

#

#

#

#

#

#

#

##

#

##

#

#

#

#

#

#

#

#

##

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

##

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

#

##

#

#

#

#

#

##

#

#

#

#

#

#

#

##

#

##

#

#

#

#

#

#

#

##

#

#

# #

#

#

(a)

(b)

Figure 3: Representation of Thiessen polygons (a), versus ideal cellular antennaeplacement configurations (b). The ideal configuration aims to reduce overlap betweenadjacent towers. The actual towers show significant overlap as shown in (a).

Access area development was dependent on range values. Cellular companies arereluctant to share tower range information. To compensate for the lack of a definiteresponse, a variety of range values were implemented; range values varied from 200-4500m.This assumption was based on personal communication with cellular professionals.Estimates were determined by reviewing the distribution of each individual carriers towers.To be cost effective, carriers place towers in locations limiting overlap with their othertowers. These range values can be adjusted, ultimately altering the analysis.

Tower capacities are important to the analysis. In order to determine if a towerscapacity has been breached an initial capacity was required. Consequently, the capacitiesused were based on personal communication with cellular professionals. The model allowsfor capacities to be adjusted. An exhaustive correspondence with the cellular industry andits users yielded few definitive answers regarding infrastructure capabilities, which could beincorporated into the model. The capacities used in the model are designed to handle themaximum population that is in that area. If the model is run with all towers present andnormal usage patterns, there will be no areas left without service.

Stage 6: Determining cellular service supply and demand

This stage involves a union operation between the towers and the populationcoverage. The result of the union is a coverage dividing the Lower Mainland up into areaswith a cell phone user population and a tower capacity allotment. Each access area fromstage 5 will now be divided up into pieces, each with a population value. From these pieces,a different cell service supply and demand value was calculated. Each piece was given apopulation (demand) and a tower capacity allotment (supply) based on the followingformulas.

The formulas assume that the population of each piece is divided uniformly acrossthe area of each piece. Also, it assumes that all people in each piece have an equalopportunity of accessing the network regardless of location.


9

Equation 1 (demand), calculates the population of the portion of the cell tower range coinciding withthe census tract.

Equation 2 (supply), calculates the total capacity for the portion of the cell tower range coincidingwith the census tract. Demand is based on the proportion of range overlapping the census tract.

Stage 7: Determining saturated towers and remaining demand

Subtracting the demand from the supply yields remaining supply or demand. Eachtower access area is divided up into pieces, each with a remaining supply or a remainingdemand value. If any piece within the tower access area has remaining supply, that supply isre-distributed among the other pieces of the access area. This process is re-iterated until allpeople within the access area have service, or the towers capacity is saturated and unable tosupply any more phone calls. Those towers that had remaining capacity after all cell userswithin its range were satisfied, were available for the next iteration.

Those areas where cell users are left without service were used in the next iterationto determine if the remaining cell towers can service these areas.

Stage 8: Re-iteration procedure without saturated towers

A series of re-iterations were undertaken with the remaining towers and populations.The remaining towers were used to determine if any of the remaining capacity can serviceother areas with remaining population. The process was re-iterated using values from stage5. New tower access areas were defined (stage 5), based on these remaining towers. Thesenew access areas were combined with the new population coverage (stage 6), resulting in anew set of remaining towers and population coverages. This process was repeated until oneof the following three functions was met:

1) The service demand of all cell phone users have been met.2) All towers in the network are either saturated or destroyed (stage 2)3) The remaining people requiring cell service are outside of the ranges of

the remaining cell towers.

Results

Within the first five minutes following an earthquake, those people who have accessto a cellular phone will attempt to access the network. Disruptions to the cellular networkwould occur in the event of an earthquake. This would compromise the integrity of the

Equation 1: Piece Population = Piece area / Total tract area * Tract population

Equation 2: Capacity Allotment = Piece area / Total tower area * Tower capacity


10

network, resulting in the creation of gaps in the service areas. Further disruptions to thecellular network could occur as a result of further attempts to access the network owing tothe concentrations of people at the time of the earthquake. Gaps in the service network willhighlight areas where the network needs to be strengthened and where problems can beexpected to occur.

Modeled Scenarios

Ten scenarios were run with variations in time of day, presence of earthquakedamage, and various percentages of the population accessing the cellular network. Resultsshow the impacts to the cellular network and areas of concern where the network can nolonger be accessed. Diagrams have been included to show areas where there are remainingpeople that cannot access the cellular network.

Control ScenarioA control scenario was run to ensure that the network would be operable during

normal daytime and evening population distributions. The model was run with all towersoperable and with 25% of all cell phone owners accessing the network. This number wasused as a guideline to the number of expected cell phone users at one time on the network.Actual cellular providers base the network traffic on a calls per hour basis, and 25%approximates those expected values. The control scenarios found that the network wasindeed operable for all towers and that all areas were receiving service (Figure 4 and Map 7)

Figure 4. Map showing the output from the control scenario. All white areas are areas where all usersare allowed access to the network. Light grey areas are areas outside the coverage of the network.

Subduction Earthquake Scenarios

Several subduction earthquake scenarios were run to evaluate the response of thenetwork. A subduction zone earthquake of a 9.5 magnitude was simulated with theepicentre located at 123o 18’ 00” W and 49o 00’ 36” N. Scenarios were carried out during


11

both night and day times and with variations in the number of cell phone owners actuallyusing their phones.

The largest problems occur when a large number of users attempt to access thenetwork. Figure 5 (a through h) show the results of these scenarios. Larger colour maps ofFigures 5a and 5e can be found in Appendix 2. It can clearly be seen that greater networkoverloads occur with increasing cell phone owners accessing the network. This highlightsthe need for emergency preparedness and the importance of educating the public so thatnetwork overload does not occur in the aftermath of an earthquake. The differencesbetween day and night population distributions show the change in distribution of problemsdepending on the timing of the earthquake. In the daytime scenarios the network problemsare largely centred on urban areas while problems are more evenly distributed in the nighttime scenario.

Areas of concern vary depending on the timing of the earthquake. Major areas ofconcern during the day include Richmond, Vancouver Airport, North Burnaby, Langley,New Westminster and the UBC Endowment Lands (Map 6). During the night time scenariomany of these problem areas change and network coverage is insufficient of larger moreevenly distributed areas (Map 5). Many of the areas with major problems are reduced indemand but more areas are affected.

The following figures show the results of several earthquake scenarios; light greyareas represent areas outside of the cellular coverage area, dark grey areas indicate areaswhere people cannot access the network and the clear areas indicate areas where coverage issufficient.


12

Day Time Scenarios90

% o

f ce

ll ph

one

user

s at

tem

ptin

g to

acc

ess

netw

ork

Figure 5.(a)

75%

of

cell

phon

e us

ers

atte

mpt

ing

to a

cces

s ne

twor

k

Figure 5 (b)


13

Day Time Scenarios

50%

of

cell

phon

e us

ers

atte

mpt

ing

to a

cces

s ne

twor

k

Figure 5 (c)

25%

of

cell

phon

e us

ers

atte

mpt

ing

to a

cces

s ne

twor

k

Figure 5 (d)


14

Night Time Scenarios90

% o

f ce

ll ph

one

user

s at

tem

ptin

g to

acc

ess

netw

ork

Figure 5 (e)

75%

of

cell

phon

e us

ers

atte

mpt

ing

to a

cces

s ne

twor

k

Figure 5 (f)


15

Night Time Scenarios

50%

of

cell

phon

e us

ers

atte

mpt

ing

to a

cces

s ne

twor

k

Figure 5 (g)

25%

of

cell

phon

e us

ers

atte

mpt

ing

to a

cces

s ne

twor

k

Figure 5 (h)


16

Statistical Overview

Statistics plays an important role in the verification of the spatial accuracy of thecellular point coverage. The accuracy is important to the entire analysis, as all data isinterdependent, (Appendix 6).

The sample set consists of fifteen cell sites in Richmond and fourteen cell sites inNorth Vancouver. Using a geocoded street map from the web page mybc.com, queries weredone using the addresses of the cell towers. The Euclidean distance was measured betweenthe two points based on an x,y coordinate system. The statistical software Excel was thenused to compile the standard deviation of the results in the two study areas.

Richmond cellular towers had a standard deviation of 485.14 metres in the xdirection and 382.1 metres in the y direction. This is a considerable amount of error. In theproject the cellular towers were plotted using the latitude and longitude coordinates from thegovernment. The queries performed on the street network of mybc.com were done usingthe addresses of the cellular towers. These addresses do not necessarily coincide with theactual location of the cellular towers. Richmond has rural as well as urban areas. It wasobserved that lot sizes are generally larger in rural areas in comparison with urban lots. Alarger lot means that there is more area to locate a cell tower. The latitude and longitudewould not necessarily coincide with the resident addresses, leading to the large standarddeviation.

In North Vancouver the results yielded a standard deviation of 68.4 metres in the xdirection and 57.1 metres in the y direction. The lower error may be attributed to NorthVancouver being predominantly urban. This significantly reduces the space wherein to placea tower, as the lots are smaller.

Discussion: Problems and Limitations

1. Data

Accurately modeling the cellular network requires an extensive collection of data.Several factors prevented the collection of a complete database. An issue that runs throughall aspects of Canadian GIS is the lack of access to data. Production of data is a costintensive process. Public and private agencies have invested considerable resources intosuch endeavours; therefore they cannot afford to freely distribute the information collected,without recovering some of the cost.

Temporal accuracy was difficult to maintain. The information readily available wasolder, as cost recovery was no longer a concern. The orthographic imagery used as the basemap was collected in 1995. Since then much has changed in the lower mainland as a resultof rapid population growth. The cellular tower network has expanded to meet the growingdemand.


17

Time constraints hindered data collection. Communication between the variouslevels of bureaucracy required more time then allotted. Delays in obtaining data fromsecondary sources deferred the forward process of the project.

The lack of standards within available data caused confusion in such areas as thelineage of the information. The inclusion of metadata is essential to understand keycharacteristics of the data. Without metadata, it was difficult to meet the full potential of thedata. Metadata was unavailable for some of the data used in the project. Software providedby Mobility (Nhematis) lacked sufficient metadata. Projection and attribute classes were notspecified, therefore causing problems when combining with other data.

2. Digitizing

Missing data had to be manually input to complete the dataset, which lead topossible digitizing errors. Feature identification from orthophotos was often problematicdue to difficulties distinguishing features. One such example is the random size and shapeof churches made precise identification difficult. Once identified the accurate shapecharacteristics were not maintained in the digitizing process.

Nhematis has been designed to assess a broad range of hazards in multiple regions inCanada; therefore the data is built on a geographic projection. This projection is idealizedfor shapes drawn in equatorial locations. When looking at regions other then equatorial,distortions occur. Nhematis’ MMI maps, which are based on the geographic projection, arenot applicable to any realistic analysis. In equatorial regions 1 north is equal to 1 east,unfortunately in the study area 1 north equals 6 east. This causes the concentric circlescreated in Nhematis to form ellipses on the ground.

Personal communication with Nhematis' developers revealed numerous parallelsbetween this project and the development of Nhematis. Cellular network technology iscomplex. Representing this complexity in a GIS platform posed complications.Assumptions were made in an effort to balance complexity of the network with thecapabilities of a GIS. Further assumptions were made to compensate for the limitations ofdata collection, which could cause error.

4. Error Propagation

Uncertainty in the lineage of the data caused the potential for error propagation.The location of the personal communication services (PCS) cellular towers were obtainedfrom Mr. Steve Romaine, a private citizen with an interest in cellular technology. Mr.Romaine operates a website containing a map of approximate cell tower locations. The mapsymbols used, misrepresented the size of the cell towers, causing possible error in placementof their location. Through visual approximation these locations were subsequently added tothe existing analog cellular tower coverage. This compounded the initial error in the celltowers locations.


18

The developers of Nhematis faced the same problem when modelling naturalhazards. The intricate nature of natural systems makes it difficult to replicate them. Thelack of full understanding required assumptions to model a process. Most models are arepresentation of reality, which can only take into account a select number of factors(Heuvelink, 1999). Finer details in the data are selectively removed to generalize the process.

5. Fuzzy Logic

Delineation of service areas was imposed using a binary classification system; acellular user is either within a towers service area or out of its range. This is a very simplifiedexplanation of the network structure. There is not a crisp boundary between service areas; itis vague and inconsistent. Incorporating fuzzy logic into a GIS system would be beneficialin this case. Gradational membership to a user area of cell tower would make the analysismore realistic. (Burroughs, 1999)

6. Projections and Scale

It is critical that coverages be of the same projection so that they overlay properly.Analysis done using Nhematis would not overlay with the coverages made in ArcView, astheir projection was not compatible. A change in the projection of the Nhematis materialresulted in its distortion. It would have been beneficial if there were a standard form ofprojection for all coverages. (DeMers, 1997)

The data used in this project was in a variety of scales. Problems overlaying dataoccurred as the coverages were in different scales. Without appropriate metadata, scaledetermination was left to trial and error.

7. Modeling Social Behavior

The ability to predict mass response to natural hazard scenarios was difficult ashuman response is unpredictable. The model used in the project assumes that people willproceed to the closest emergency response facility following the initial event. An individualsknowledge of the area, their mobility, and their state of mind will influence how they react.As of yet models are unable to fully capture the variability involved in society. The numberof people converging in each response centre will affect the tower usage in the vicinity. Thenumber of people is a postulation that greatly affects the analysis.

Conclusion

A number of additional data sets and further information would have increased theaccuracy and functionality of this project.

1. The release of more precise cell tower information. This would includelocational accuracy, service area, and tower capacity.


19

2. Current orthographic photos, so that heads up digitising accuracy couldbe improved for more precise building location. For example, recentlybuilt schools do not appear on older orthographic photos used.

3. Better integration of software utilities. The ability of Nhematis maps tobe overlain with ArcView coverages would allow easier visualization ofthe data.

4. A wider range of coverages: including hydro-grids and elevation data.Hydro information would allow for authentic scenarios to be portrayed.The loss of electricity would lead to the removal of some towers fromthe cell network; better representing the actual effects of an earthquake.Other hazards, such as floods and landslides could have been includedwith elevation data of a higher resolution.

Due to the lack of previous research in this area, the analysis has been generalized inan effort to develop and apply a workable methodology. A number of assumptions have tobe made regarding

1. Magnitude and location of potential earthquakes 2. Prediction of population patterns during a natural hazard event 3. Cellular tower damage assessment, 4. Emergency services response.

The proposed model has successfully applied the use of Geographic InformationSystems in the assessment of vulnerability of the cellular communications network. Aninnovative approach for evaluating hazards and impacts has been presented. Furtherresearch and development of the model could provide further valuable and insightful results.


20

References

Armstrong, J.E. 1990, Vancouver Geology. (ed) Charlie Roots and Chris Staargaard.Cordilleran Section, Geological Association of Canada, Vancouver

Buurough, Peter A., McDonnell, Rachel A. 1998. Principles Of Geographical InformationSystems. Oxford University Press.

DeMers, M.N. 1997. Fundamentals of Geographic Information Systems. John Wiley & sons.

Fry, C. 1999. GIS in telecommunications. In Geographical Information Systems Volume two:Management Issues and Applications (ed).

Heuvelink, G.B.M. 1999. Propagation of error in spatial modelling with GIS. In GeographicalInformation Systems Volume two: Management Issues and Applications (ed).

Turner, R.J.W., Clague, J.J., Grouix, B.J., and Journeay, J.M., 1998. GeoMap Vancouver.Geological Survey of Canada, Open File 3511.

Victoria Times Colonist Sept. 8 1999, Final Ed. p. 3National Post July 19, 1999 p. A16

Webb, T. 1999, Nhematis Training Version Lookfar Solutions Inc. Tofino, B.C. p.19

Westervelt, J.D. and Hopkins, L.D. 1999. Modelling mobile individuals in dynamiclandscapes. International Journal of Geographic Information Science 13(3): 191-208

Web Site Addresses

Industry Canada website: http://www.canada.gc.ca

Steve Romaine’s website: http://www.geckobeach.com

Nhematis web site:http://www.nobility.com/Applications/Emergency_Preparedness/index_fr.htm

Data Dictionary

File Name Population.shpSource Statistics Canada

Field Name Field Size Field Type DescripitionTract 16 Integer Census Tract Identification Number

Municipali 25 Character Municipality NameTract_id 16 Integer Internal Census Tract Identification NumberCen_pop 10 Integer Census Tract populationCen_area 16 Integer Census Tract area

File Name Night_pop.shpSource Statistics Canada



File Name Day_pop.shpSource Statistics Canada

Modified by: Geog452 (03/00) - Added Translink population movement data



In 16 Integer Population change into census tractOut 16 Integer Population change out of census tract

Change 16 Integer Census tract population change

File Name Nv_droutes.shpSource GIS Innovations (03/00)

Modified by: Geog452 (03/00) - Digitized

Field Name Field Size Field Type DescripitionShape 10 Character Type of Object in ArcviewStreet 25 Character Name of street

Fromleft 16 Integer Street range following street from leftToleft 16 Integer Street range following street to left

Fromright 16 Integer Street range following street from rightToright 16 Integer Street range following street to rightCity_left 30 Character Name of city on the left of street

City_right 30 Character Name of city on the right of streetCsd_left 10 Integer Unknown

Csd_right 10 Integer UnknownRd_class 16 Character Type of Street

Type 16 Integer Numerical class of StreetStname_id 16 Integer Street Name indeification number

Hwyrte 16 Character UnknownGisi_id 16 Integer Internal ID number

File Name Nv_streets.shpSource GIS Innovations (03/00)








File Name Nv_schools.shpSource District of North Vancouver (03/00)

Field Name Field Size Field Type DescripitionShape 10 Character Type of Object in ArcviewArea 20 Integer Area of shape

Perimeter 20 Integer Perimeter of shapeSchools_ 16 Integer Internal Identification Number

Schools_id 16 Integer User-defined Internal Identification NumberSchool_code 16 Integer UnknownSchool_nam 30 Character Name of SchoolNeighbourh 16 Character Unknown

Type 12 Character Type of schoolTrack 10 Integer Number of fields

A_w_field 10 Integer Numbr of All weather fieldsGrass_field 10 Integer Number of Grass fieldsPlayground 10 Integer Number of Playgrounds

Tennis_court 10 Integer Number of Tennis courtsLacrosse_b 10 Integer Number of Lacrosse fieldsCourtyard 10 Integer Number of Court yards

Gym 10 Integer Number of GymsStage 10 Integer Number of Stages

Bleachers 10 Integer Number of BleachersClassrooms 10 Integer Number of classrooms

Library 10 Integer Number of LibrariesA_v_room 10 Integer Number of Audio-Visual rooms

Shops 10 Integer Number of Shop classesDrafting_r 10 Integer Number of Drafting classesScience_ro 10 Integer Number of Science classes

Computer_r 10 Integer Number of computer roomsDark_room 10 Integer Number of Dark roomsArts_room 10 Integer Number of Art classes

Music_room 10 Integer Number of Music roomsHome_econo 10 Integer Number of Home economics classesTyping_roo 10 Integer Number of Typing roomsBuildclass 16 Character Based on Nhematis Building Class assessment

Mmi 3 Integer MMI Value that school can withstand

File Name Nv_recreation.shpSource Geog452 (03/00) - Digitized

Field Name Field Size Field Type DescripitionShape 10 Character Type of object in Arcview

Id 5 Integer Internal Identification numberRecreation 25 Character Name of Recreation Center

Address 25 Character Address of Recreation CenterBuildclass 20 Character Based on Nhematis Building Class assessment

Mmi 3 Integer MMI Value that recreation center can withstand

File Name Nv_malls.shpSource Geog452 (03/00) - Digitized

Field Name Field Size Field Type DescripitionShape 10 Character Type of object in ArcviewId 10 Integer Internal Identification numberName 30 Character Name of Shopping MallBuildclass 16 Character Based on Nhematis Building Class assessmentMmi 3 Integer MMI Value that Shopping mall can withstand

File Name Nv_emergency.shpSource Geog452 (03/00) - Digitized

Field Name Field Size Field Type DescripitionShape 10 Character Type of object in ArcviewId 10 Integer Internal Identification numberemergency_ 30 Character Type of emergency centerAddress 30 Character Address of emergency centerBuildclass 16 Character Based on Nhematis Building Class assessmentMmi 3 Integer MMI Value that Emergency Center can withstand

File Name Nv_church.shpSource Geog452 (03/00) - Digitized

Field Name Field Size Field Type DescripitionShape 10 Character Type of object in ArcviewId 10 Integer Internal Identification NumberAddress 30 Character Address of churchName 30 Character Name of churchBuildclass 16 Integer Based on Nhematis Building Class assessmentMmi 3 Integer MMI Value that church can withstand

File Name Rich_streets.shpSource GIS Innovations (03/00)








File Name Rich_droutes.shpSource GIS Innovations (03/00)

Modified by: Geog452 (03/00) - Digitized








File Name Rich_schools.shpSource Geog452 (03/00) - Digitized

Field Name Field Size Field Type DescripitionShape 10 Character Type of object in ArcviewId 10 Integer Internal Identification NumberName 30 Character Name of schoolAddress 30 Character Address of schoolType 20 Character Type of schoolBuildclass 16 Integer Based on Nhematis Building Class assessmentMmi 3 Integer MMI Value that school can withstand

File Name Rich_recreation.shpSource Geog452 (03/00) - Digitized

Field Name Field Size Field Type DescripitionShape 10 Character Type of object in ArcviewId 10 Integer Internal Identification NumberName 30 Character Name of recreation centerAddress 30 Character Address of recreation centerType 20 Character Type of recreation centerBuildclass 16 Integer Based on Nhematis Building Class assessmentMmi 3 Integer MMI Value that recreation center can withstand

File Name Rich_malls.shpSource Geog452 (03/00) - Digitized

Field Name Field Size Field Type DescripitionShape 10 Character Type of object in ArcviewId 10 Integer Internal Identification NumberName 30 Character Name of Shopping mallAddress 30 Character Address of shopping mallBuildclass 16 Integer Based on Nhematis Building Class assessmentMmi 3 Integer MMI Value that shopping mall can withstand

File Name Rich_emergency.shpSource Geog452 (03/00) - Digitized

Field Name Field Size Field Type DescripitionShape 10 Character Type of object in ArcviewId 10 Integer Internal Identification NumberName 30 Character Name of Emergency serviceAddress 30 Character Address of emergency serviceType 20 Character Type of emergency serviceBuildclass 16 Integer Based on Nhematis Building Class assessmentMmi 3 Integer MMI Value that emergency service can withstand

File Name Rich_city hall.shpSource Geog452 (03/00) - Digitized

Field Name Field Size Field Type DescripitionShape 10 Character Type of object in ArcviewId 10 Integer Internal Identification NumberName 30 Character Name of BuildingAddress 30 Character Address of BuildingBuildclass 16 Integer Based on Nhematis Building Class assessmentMmi 3 Integer MMI Value that building can withstand

File Name Rich_churches.shpSource Geog452 (03/00) - Digitized

Field Name Field Size Field Type DescripitionShape 10 Character Type of object in ArcviewId 10 Integer Internal Identification NumberName 30 Character Name of churchAddress 30 Character Address of churchBuildclass 16 Integer Based on Nhematis Building Class assessmentMmi 3 Integer MMI Value that church can withstand

File Name Rich_airport.shpSource Geog452 (03/00) - Digitized

Field Name Field Size Field Type DescripitionShape 10 Character Type of object in ArcviewId 10 Integer Internal Identification NumberName 30 Character Name of buildingAddress 30 Character Address of buildingBuildclass 16 Integer Based on Nhematis Building Class assessmentMmi 3 Integer MMI Value that building can withstand

File Name towers.shpSource Industry Canada - 1999 data

Modified by: Geog452 (03/00) - Data import into Arcview, projection change, added data fields

Field Name Field Size Field Type DescripitionShape 8 Character Type of object in ArcviewCapacity 16 Integer User Capacity of towerRange 16 Integer Range of towerType 16 Character Type of cell towerCarrier 30 Character CarrierF 10 Integer Cell tower frequencyR_e 12 Integer Record Identifier number assigned at time of licence applicationlocation 30 Character Location of towerE 10 Integer EMC status codeP 10 Character Type of antenna polarization usedLicensee 20 Character Licensee of towerClassna 15 Character Class of station for the frequency being usedNature 15 Character Nature of service provided by the frequency assignmentSic 10 Integer Licensee Standard Industrial ClassificationIdent 20 Character Call sign assigned to towerNomob 8 Integer Total number of users authorized to communicate with the towerDate 8 Integer Date of license issuedBw2_emissi 10 Character Necessary bandwidth of the second emissionBw1_emissi 10 Character Necessary bandwidth of the first emissionMmi 3 Integer MMI Value that building or tower can withstandBuildclass 16 Character Based on Nhematis Building Class assessmentOn_build 16 Character If tower is on building: set to YTwr_id 5 Integer Identifictaion Number

File Name Ranges.shpSource Geog452 (03/00)

Field Name Field Size Field Type DescripitionShape 8 Character Type of object in ArcviewArea 16 Integer Area of range circletwr_id 5 Integer Tower id that is found in towers.shptwr_cap 16 Integer Cell tower capacityRange 16 Integer Range of cell towerid_string 10 Integer Identification numbertwr_area 16 Integer Cell tower area

File Name traffic.shpSource Greater Vancouver Regional district

Field Name Field Size Field Type Descripitionshape 8 Character Type of object in ArcviewId 16 Integer Internal Identification NumberLink 10 Integer Link NumberFrom_node 8 Integer Id of the From nodeFrom_x 8 Integer X location( from)From_y 8 Integer Y location (from)To_node 8 Integer Id of the To nodeTo_x 8 Integer X location (to)To_y 10 Integer Y location (to)Link_length 10 Integer Length of linkAllowable_ 10 Character Type of transportation travellink_type 10 Integer Link typeLanes 5 Integer Number of lanesVolume_del 10 Integer Nominal capacityVehicle_vo 10 Integer Number of vehiclesAverage_li 10 Integer Speed limitsTransit_pa 10 Integer Number of transit passengers

** NoteVarious files have been complied through a number of different sources. For more specific information on files produced by outside sources, please contact the sourcecompany

Documents

Vulnerability of the Cellular Telecommunication Network in the