[ieee 2012 7th telecommunications, systems, services, and applications (tssa) - denpasar-bali,...

Design of Text-Based Map for Smartphone Platform in Low Bandwidth Environment:

a Network Layer Approach

Firman Azhari School of Electrical Engineering and Informatics

Bandung Institute of Technology Bandung, Indonesia

[email protected]

Abstract—Smartphones and tablets are used by millions of people for various purposes. One of the purposes is map and navigation service. However the use of map services is sometimes limited by the data-rate or the delivery speeds due to low bandwidth environment. This paper describes simplified map technology using network layer approaches. The proposed system employs text-based map which is friendly with low download rate system.

Keywords: smartphone; map; telecommunication; network; bandwidth

I. INTRODUCTION Land navigation system is now being the part of human

life. People need to know new environments or places as soon as possible since their first visit to the place. Nowadays people are using their smartphone for plenty applications, including land navigation services. Map technology is crucial for delivering good navigation service.

On the other hand, in developing countries, high speed data transfer rate is still a major problem, both for end-users and also for service providers. Implementing broadband services in developing countries is limited because three main reasons: (1) limitation of the access of new technology (2) inconsistency of regulation from the government, and (3) unprofitable for telecommunication network provider (business reasons). Due to those reasons, most sophisticated services cannot be provided for end-users, considering service delay and user convenience. One of them is land navigation service including the map service.

This paper is trying to provide solution for that problem. This paper is not covering the navigation service that is embedded to GPS consumer products available in the market. This paper only covers the existing navigation service that is used in smart phone and tablet. Navigation service in GPS consumer products use different approach compared to the service in smart phone, since there is no data service or data plan required to be able to use the navigation service. All the map data is embedded in the device. Each system has its own advantages and disadvantages. One of the biggest advantages of using navigation service in smartphone or tablet is the utility of the device. GPS consumer product cannot do anything but the navigation service. Smartphone can be used for unlimited

applications. So in consumers’ point of view, owning a smart phone give lot more value than owning a GPS consumer product.

With all those reasons, author decided to develop new simplified map technology to be implemented in a smart phone or tablet which has low data-rate service.

II. EXISTING SYSTEM

A. Map Technology on Smartphone Platform Many web-based map technologies are developed since

year 2000. Those technologies are replacing conventional map that only can be accessed via Map Software and can be accessed by buying the hardcopy versions. People are using them now for daily-use accessed both from personal computer and also from mobile devices, including smartphone and tablet. Some popular map products that are being used until today are Google Maps (http://maps.google.com) and Bing Maps (http://www.bing.com/maps/) from Microsoft. Their services are usually including Map Images, get directions, and explore places and addresses. They open some of their service to be used by developer via API (Application Programmer Interface), so their service will be widely used.

Figure 1. Typical Web-based Map Product (Google Maps)

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Figure 1 is the example of google map service. Those map and navigation products are usually packed in an interactive mobile application that run on certain platforms or operating systems, such as Android, iOS, Blackberry OS, and Windows Phone.

B. Challenges There are several challenges appeared when those advanced

map and navigation technology applied in real life environment, especially when those are applied in a smartphone with low-bandwidth data access. These kinds of environments are becoming majority in such developing countries with low data rate penetration.

There are some test methods to check how fast a delivery speed of a system. Author has run a test with Mozilla Firefox internet browser with Firebug extension. The method is by retrieving the loading speed of a 256 pixels x 256 pixels sized picture both from Google and Bing. We can calculate the average delivery speed by dividing the size of the picture with the average speed from the request starts until the whole picture is received, as in

Author had run the test in Bandung, Indonesia. The test is run 10 times in different periods and the average delivery speed for the most popular map service in the world is shown in table I.

TABLE I. TERMS COMPATISON BETWEEN TELECOMMUNICATION SYSTEM AND PRPOSED SYSTEM

Google Maps Bing Maps

Image Size 13.4 KB 10.8 KB Average Onload Time 2383 ms 578 ms

Average Delivery Speed 5.62 KB/s 18.68 KB/s

This test method has been run by some internet users around the world. The results, which vary in different countries, are shown in table II.

TABLE II. TERMS COMPATISON BETWEEN TELECOMMUNICATION SYSTEM AND PRPOSED SYSTEM

Country Google Maps Bing Maps

Greece 80.4 KB/s 188.2 KB/s

UK 270 KB/s 212 KB/s

Japan 100 KB/s 169.8 KB/s

Italy 125 KB/s 60.7 KB/s

India 38 KB/s 13.58 KB/s

Indonesia 5.62 KB/s 18.68 KB/s

Table II is not representing the exact average delivery speed comparison for two popular services, instead of to represent delivery speed comparison among countries. Developing countries like India and Indonesia have less delivery speed. It may happen due to less bandwidth available in those countries. Smart phones and tablets have screen size that ten until hundreds times bigger than the sample map image used in the test, especially when we are using tablets. Assumed we are using 720px x 1280px-sized smartphone and load the map service on 80% of the screen. So, we will load around 11.25 times bigger image than the sample 256x256 image. So, in author’s case, Google Maps user needs around 25 to 30 seconds to load a full screen map image in a smart phone. It is not considering user that will change the zoom control, panning the map, and other map controls when the map image is not what the user wants. Those periods are too long considering good user experience for a mobile application. If application implements time-out system for slow response request, this would be a critical problem, especially for user in low bandwidth environment,

III. PROPOSED SYSTEM Author has designed a map technology that simplify the

system both in terms of algorithm and also the size needed to be downloaded by user’s phone. The proposed system is based on the challenges that have been described before.

Firstly, there will be an explanation about how telecommunication network can help author to model and create map technology. After that, those model will be developed by adding related parameters and write those parameters in a text file. Finally, author will explain the implementation plan for this simplified map technology.

A. Telecommunication Network Approach Telecommunication Engineering has a very robust concept

in separating complicated processes into several layers. Those are some standards developed, including OSI layers and TCP/IP layers. They have the same layer called “Network” layer, which has responsibility to route the data from a node to other nodes or to workstations, both desktop or personal computers and also mobile stations.

Figure 2. Router connections which is similar with junctions connections in transportation system.

Average Delivery Speed = Data Size

Average Onload Time (1)


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4J1

4J3

3J2

3J4

We can see in Figure 2 how routers, network layer devices, connect each other. They are connected by links that come out from routers’ ports. That is the basic concept that will be used in modeling a new map technology. Firstly, we have to compare some terms used in the new map concept with the telecommunication network concept. The comparison is stated in Table III.

TABLE III. TERMS COMPATISON BETWEEN TELECOMMUNICATION SYSTEM AND PROPOSED SYSTEM

Terms Comparison Proposed System Telecommunication Function

Junction Node/Router As routing device to connecting nodes.

Post_junction Port gateway for the router / gateway for a junction.

Street_point Link Connecting 2 ports / conneting 2 post_junctions

For the next explanation, let’s call Junction, Post_junction, and Street_point as domains. One domain has different parameters that will be used to connect one domain to other domains. The relationships between those domains are visualized in Figure 3.

Figure 3. Visualization of Text-Based Map Algorithm with Telecommunication Network Approach

We can see that the relationships between them are the same with the transportation concept which has plenty of junctions and connected each other by streets or roads. Those are several different colors in figure 3 which have different means or domains.

• Blue dots with white circle

These dots represent junctions. In a real world, there are many types of junctions, such as intersection, ‘T’ junction, and roundabout. Different color in the white circle means different types of junction. One junction must contain several parameters:

o ID: the primary key of the junction database. Each junction has unique ID.

o Name: the name of the junction. This is not really necessary but this will help data entry process to differ one junction to others.

o Junctioncat: means the category or type of the junction. This is an integer number represents how many post_junction connected to this junction. It is the same with how many ports does a router have.

o Latitude: a double value of earth latitude of the junction position.

o Longitude: a double value of earth longitude of the junction position.

o City: the name of the city where the junction located.

o Area: the area position of the junction. A city will be divided into several areas. This will be explained later.

• Black dots

These dots represent post_junction domain. Post_junction is the gateways for every junction. For example, an intersection has four post_junctions a ‘T’ junction has 3 post_junctions, and so on. We use this domain mainly for routing purposes. One post_junction must contain several parameters:

o Junction_id: the ID of the junction connected to the post_junction

o Destjunction_id:the ID of the junction where the post_junction is headed to. For example: if a post_junction connects to junction 4J1 and headed to junction 4J3, the junction_id will be 4J1 and the destjunction_id will be 4J3

o PostjuncID: an integer number to differ one post_junction to others that connect to the same junction. The value starts from 1 and the maximum value of PostjuncID is the related to the junctioncat value.

o Blocked: a Boolean value represents if the road connected to the post junction is blocked or not.

o Latitude: a double value of earth latitude of the post_junction position.

o Longitude: a double value of earth longitude of the post_junction position.

o StreetID: physically, a post_junction is the part of the street_point. This streetID is related to the Street_point domain.

o City: the name of the city where the post_junction located.


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• Light blue dots

These dots represent street_point domain. Like a mathematical terms, a line is formed by several dots, so is a street. In this concept, a single street is formed by several street_points. One street_points must contain several parameters:

o ID: a primary key of this domain. Each street_point has a unique ID.

o streetID: one street has a single streetID, so several street_points which are located in the same street will have the same streetID.

o Address: The name of the street.

o Latitude: a double value of earth latitude of the street_point position.

o Longitude: a double value of earth longitude of the street_point position.

o City: the name of the city where the street_point located.

• Red dots

These dots represent objects located in the street, such as hospital, restaurant, gas station, and many other objects. This domain contains the same parameters with domains above, including the name of the object.

Figure 4 describes the relationship between those domains. We can make the relationship like database object relationship.

Figure 4. Visualization of Text-Based Map Algorithm with Telecommunication Network Approach

B. Text-Based Map Technology The main concept of this proposed map technology is to

implement the concept into text-based files. The proposed system contains text-based files representing each domain or dots, related to the previous explanation.

These are the sample of an entry of each domain. They have the same structured template that has to be followed so the text-based map has a standard. That is necessary for the data entry procedure.

• JUNCTION { “id": 1,

"name": 1,

"junctioncat": "4",

"latitude": -6.873251,

"longitude": 107.619133,

"city": "Bandung",

}

• POST_JUNCTION { "junction_id": 1,

"destjunction_id": 5,

"postJuncID": 3,

"blocked": "false",

"latitude": -6.890981,

"longitude": 107.611371,

"streetID": 1,

"address": "Jalan Ir. H. Djuanda",

"big_dest": "Dago Pakar",

"city": "Bandung",

},

• STREET_POINT { “id": 1,

"streetID": 1,

"address": "Jalan Ir. H. Djuanda",

"latitude": -6.873251,

"longitude": 107.619133,

"city": "Bandung"}

Those are the example of text-based domains in JSON format. JSON, stands for JavaScript Object Notation, is one of example text-based open standard design for human-readable data interchange. This standard can be used if developers plan to implement this concept into Android, Blackberry, or other platform that use Java as their development platform. If developers feel more comfortable working with XML format file or any other text format, they can modify the code with structures refer to the previous example.


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Postjunction.txt Junction.txt Street_point.txt Objects.txt Ads.txt

C. Routing Concept & Implementation Plan The most important thing to a map technology is the ability

to be used for routing process. Routing process is needed to provide many other features, such as suggest driving route to user, find the address, define how far a road or a trip is, and many others. This paper will not discuss the routing technology in details. The concept is by using the parameters in those three domains explained before, routing process can be implemented.

Firstly, there are 3 main domains that have to be existed as before explanations. Those domains have several parameters that connect each other as seen in Figure 4. Routing process is related to the destination position and the current position of the user.

Users’ smart phone, typically, has standard sensors embedded on their devices, such as, Accelerometer, Gyro, GPS module, digital compass, and many other sensors depending on the manufacturers. Those sensors’ output can be exploited and can be used as initial and current state for the devices. The most related sensors with the proposed system are GPS module and digital compass. So, the minimum requirements of the proposed system in client side are:

• Smart phone with advance operating system (Android, iOS, Blackberry OS, Windows Phone)

• Embedded GPS module, • Embedded Digital Compass, • Data service

Please note that the last requirement is the challenge defined in this paper. User still need data access to download the map, but high bandwidth is not necessary. To implement this concept, author has provided implementation scenario that is visualized in figure 4.

Figure 5. Implementation Plan for Proposed System

The map in figure 5 only visualizes the position of the handset. These are the steps of proposed scenario with explanations.

1. Text-based map will be divided into several files related to certain area or region. This is meant to shorten the looping process in the processing algorithm. This is also meant to make the text file’s size as small as possible (max. 100 KB/file).

2. Handset will download some text files when entering certain area or region. The position of the handset is determined by GPS module embedded in the smartphone. Postjunction.txt, Junction.txt, and Street_point.txt are mandatory files that will form the map. The other files are optional.

3. After downloading files, smartphone don’t need to use data access anymore, except the handset is going outside the current region or entering new region.

4. Handset will determine the direction of a user by using digital compass module. We also can calculate the deviation between user direction and also the relative direction from user to any other object near him. We can calculate it with simple trigonometry

5. The most important value that can be determined is the length between user’s handset and any other point that is a member of any of three or more domains mentioned before. Mathematically, we can solve it by using Haversine formula. The Haversine formula is an equation important in navigation, giving great-circle distances between two points on a sphere from their longitudes and latitudes. We need to implement this on the smartphone. Code below is an example of Haversine formula implementation in Java.

6. By length value, relative direction value, and parameter relationships, we can form a navigation or routing process based on a text-based map.

import com.google.android.maps.GeoPoint; public class DistanceCalculator { private double Radius; // R = earth's radius (mean radius = 6,371km) // Constructor DistanceCalculator(double R) { Radius = R; } public double CalculationByDistance(GeoPoint StartP, GeoPoint EndP) { double lat1 = StartP.getLatitudeE6()/1E6; double lat2 = EndP.getLatitudeE6()/1E6; double lon1 = StartP.getLongitudeE6()/1E6; double lon2 = EndP.getLongitudeE6()/1E6; double dLat = Math.toRadians(lat2-lat1); double dLon = Math.toRadians(lon2-lon1); double a = Math.sin(dLat/2) * Math.sin(dLat/2) + Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2)) * Math.sin(dLon/2) * Math.sin(dLon/2); double c = 2 * Math.asin(Math.sqrt(a)); return Radius * c; } }


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IV. CONCLUSION After explaining the main concept of the design, these are

conclusions of this paper in terms of the proposed system:

1. Telecommunication System, especially in network layer, can be adapted as the concept of transportation navigation system because of the similarity.

2. Recent-known map technology requires high bandwidth access to download map-image which is problem for developing countries.

3. Text-based map have much smaller size of data compared to image-based map in the market.

4. Three main domains that have to be exist in the proposed system are Junctions, Post_Junctions, and Street_Points, which are similar to Routers, Port, and Link in Network Layer.

ACKNOWLEDGMENT Thanks to Prof. Dr. Suhono Supangkat for the internship

opportunity for “Smart City” development. Credits are also for

Dr. Baskara, Mr. Ari Ronaldo, and Mr. Mezano as author’s supervisor at laboratory. Thanks to Dr. Eueung Mulyana, Dr. Hendrawan, and Dr. Tutun Juhana from Telematics laboratory, and also Prof. Andriyan Bayu S. from Telecommunication, Radar, and Microwave Laboratory.

REFERENCES

[1] Flood, J.E, Telecommunication Networks, 2nd ed, IET, 1997 [2] W. Geller, S. Gottwald, M. Hellwich, H. Kastner, and H. Kustner, The

VNR Concise Encyclopedia of Mathematics, 2nd ed., ch. 12, Van Nostrand Reinhold: New York, 1989

[3] Calculate_Distance_Between_Two_Points_on_a_Globe[Online]http://www.codecodex.com/wiki/Calculate_Distance_Between_Two_Points_on_a_Globe

[4] Norman,Brian.Mapping APIs [Online] http://www.earthware.co.uk/blog/index.php/2009/12/mapping-apis-google-maps-vs-bing-maps-part-3-download-sizes-and-delivery-speeds/

[5] Romuald Ireneus 'Scibor-Marchocki, Spherical trigonometry, Elementary-Geometry Trigonometry web page (1997)


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