Mobile and Wi-Fi Geo location Using Google Latitude - CiteSeerX

Mobile and Wi-Fi Geo location Using Google Latitude Varun Pande, Wafa Elmannai, Khaled Elleithy Department of Computer Science and Engineering University of Bridgeport Bridgeport, CT 06604, USA {vpande, welmanna, elleithy}@bridgeport.edu Abstract—The development of Geographical location standards has opened the doors for new strategies and ideas for location based services, specifically for wireless mobile devices. With the help of Geo location, it has become easy to get information of specific location or find the current locations on our mobile devices. Using networks like Wi-Fi, Cellular networks or GPS positions, it has become a function of second nature for letting our wireless mobile devices know our locations. However, if a wireless mobile device does not support GPS service, we cannot access Wi-Fi data. Therefore, in this paper we present an application as a proof of concept (POC), with the help of Google Latitude to define the location of a specific Wi-Fi tower that in turn enables us to locate the approximate location of the wireless mobile devices without GPS support. Key Words- Geo location; Wi-Fi position; Google Latitude.

I.

INTRODUCTION

The most commonly used location based service application for the wireless mobile devices is the Google latitude, which is provided by Google. With the use of a Google account, the user can set his location on the Google map, view location of other people or businesses and have control over his privacy of location. The privacy option enables a user to hide his location for specific users or even specify the city or the country where his information can or cannot be seen. In order to get any wireless mobile device’s (mobile phones or laptops in our example) location; we need to have GPS position of that wireless mobile device. This information is based on calculating the mobile devices’ position out of the GSM’s geographic location data [1]. Hence, the infrastructure is already provided in the current world using GPS satellites for locationbased services throughout the world. Though this method revolutionized the location-based services, the downfall is that we still need access to GPS data every time we are looking for our location. Also, the synchronization between the satellites and our application fails sometimes; thus, taking more time to define a location (happens mostly in car based GPS systems). If we don’t have wireless network, we cannot get the location data.

Also, to access the GPS or search for GPS satellites, we need a lot of precious power resources that is the most challenging issue with wireless mobile devices. In other words, many of us must use Google location services using mobile phones to display our location. For example the Facebook application could be used to check in our location using the Google location services. On an observational standpoint, we cannot use this application on our desktop system or laptops that are connected to a LAN or wired connection for defining our locations. In this case, we have to reenter our location that is the address every time we need just in order to define our location or find an address. But if we access the Internet or the application on a laptop or desktop via a wireless signal, we should able to define the location. This is quite extraordinary but the reason behind this is that the IP address cannot alone determine the location of our device. Thus, to understand the concepts presented in this paper we will need to explain in this introduction what is an IP address, how the IP address is assigned and finally how can the IP address be used in defining the location of wireless mobile devices. After this overview, we are going to explain how Google Gears Geo location technique works. A. Over iew of IP Address: IP address is the address of the Internet protocol. Each device on a specific network has its own IP address, for example: laptop, PC or printer within a network [2]. 192. 168. 255. 255

11000000 10101000 Network Address

11111111

11111111

Host Address

Figure1: The identification of the network and addressing the location

The IP address of any device identifies two parts: the identification of the network and addressing the location as shown in Figure 1. So, from the IP address we can know the name of the host or the network, its location and the router to being there [3]. IANA has the responsibility of managing the address spaces that are distributed globally in accordance with the hierarchical structure shown in Figure 2. First, the IPv4 address was assigned as 32bits number [2]. But due to the rapid growth of the Internet, the Internet Engineering Task Force (IETF) proposed IPv6 in 1995 [3]. An IPv6 address consists of a 128bits. Then 1998, IPv6 became RFC 2460 standard. Furthermore, this IP address usually appears in readable text file. It contains binary numbers and each part of these bits meets a specific need as explained above.

2.

Lateration: This method can be used if we have more than one site that surrounds the query location. Then we need to measure the distance between those positions as shown in Figure 4. First, we need to get from each position the minimum of its three signals. Then, either we calculate the difference in the time of the signals or the difference of signal runtime. However, if the surrounding positions are three we call this method Trilateration. Furthermore, if we have more positions that are pinpointed for the queried location, we call it Multilateration. Questioned position

P1

P2

P3

Figure2: The hierarchical structure of IANA

However, the Internet Assigned Numbers Authority (IANA) internationally allocates these IP addresses. Then, IANA helps in assigning these IP addresses with local entities as shown in Figure 2. In general using the IP address we can know the location in case we know the ISP (internet service provider) and how the ISP works on assigning IP to their individual devices. B. Position Calculation: There are three basic methods that are used to calculate the position of the device [5]. 1.

Figure4: example of measuring the position using the Lateration

3.

Centroid Localization: This method also considers the triangle shape. The query location should be centralized and the important function is to know the received signaled sites. Based on this sited we can get the measurement or the desired position. The method is shown in figure 5 which demonstrates how based on the giving signals of other position, we can calculate the centralized one.

Triangulation: We consider this method exactly as the triangle in the mathematical rule. So, the query is to find the location that is between two angles of two positions (S1, S2) as shown in figure 3. If we know the distance of the two sites, then easily we can calculate the location by using the two angles. S3: Question Location Figure 5: Centroid Localization method to measure the centroid position

S1

S2 Distance

Figure 3: Triangulation method for measuring question location between two sites.

II. RELATED WORK In order to eliminate the estimation of noisy location, the algorithm of orientation filter and a Newton Trust Region (TR) was applied in [6]. Their implementation was based on one of the Wi-Fi devices along with a digital scope that is called

Google Nexus One. The results of their experiment lead to 90% positive results within 2.45m while the distance’s average error is 1.82m. To generate the position signature from the party of the raw signals of GPS from different numbers of satellites, Denning and MacDoran proposed a new location-based authentication mechanism [7]. The authors relied in their experiment on one concept which is those signatures are hard to forge. That was based on random received signals. This paper is efficient but the technique validation was missing. Similarly in [8, 9] in order to prove the location of wireless nodes, such response schemes were proposed. These techniques proved that the AP could measure the wireless nodes location with retorting to a node that sent if the specific range of an actual AP was provided. These papers could efficiently use the numbers of receivers to measure the wireless nodes’ positions with the help of characteristics of RF propagation. The access control scheme that is “Lockr” was introduced in [10] depending on the relationship of the metadata. The users are able to exchange the metadata between each other; that could emphasize the social verifications of this scheme. However, the experiment required that both sides should sign a digital consent in order to prove the right information. This can provide the location evidence. Hence, to provide better security on exchanged information, the protocol was developed based on the verification mechanisms. It is concluded that the authors were working to introduce a scheme that provides a social relationship for getting location proof. III.

PROPOSED WORK Start

Get the Wi-Fi adapter

Enumerate the available Wi-Fi towers

HTTP request and parse the response

Location

Stop

Figure6: Flow chart of our proposed application

In this section we are explaining the proposed system’s architecture as shown in Figure6. 1.

This sample C# code is explaining how we can get access to the Wi-Fi adapter which is required since we need a static location in the network and a Wi-Fi adapter connected to a LAN cable which is always a static location:

Json = @"{ ""host"" : ""Test"", ""radio_type"" : ""unknown"", ""request_address"" : true, ""version"" : ""1.1.0"",wifi_towers"" : [ ";lstWifi.Items.Clear(); 2.

Enumerate the available Wi-Fi towers and concatenate the JSON string The JSON strings allows us to decipher the WI-FI network towers. This shows the signal strength of multiple WI-FI networks, which allows us to justify the location of a wireless mobile device.

System.Text.StringBuilder SB = new StringBuilder(); foreach (var oWlan in lstWlanBss ) { ListViewItem lstItem = lstWifi.Items.Add(System.Text.Encoding.UTF8.GetString (oWlan.dot11Ssid.SSID)); lstItem.SubItems.Add(CalculateSignalQuality(oWlan.lin kQuality).ToString()); string MAC = ConvertToMAC(oWlan.dot11Bssid); lstItem.SubItems.Add(MAC); SB.Append(@"{""mac_address"" :"""); SB.Append(MAC); SB.Append(@""""); SB.Append(@", ""signal_strength"" :"); SB.Append(CalculateSignalQuality(oWlan.linkQuality). ToString()); SB.Append(@", ""ssid"" : """); SB.Append(System.Text.Encoding.UTF8.GetString(oWla n.dot11Ssid.SSID, 0, (int)oWlan.dot11Ssid.SSIDLength)); SB.Append(@""" },"); } Json += SB.ToString().Substring(0, SB.Length - 1); // copy all except last "," Json += "]}"; textSent.Text = Json;

3.

The second part is to form an HTTP request and parse the response This is the request which allows us to get the IP address of the static location and the response lets us confirm if our mobile device is connected to that wireless network:

HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(@"http://w ww.google.com/loc/json"); request.ContentType = "application/json; charset=utf8"; request.Accept = "application/json, text/javascript, */*"; request.Method = "POST"; using (StreamWriter writer = new StreamWriter(request.GetRequestStream())) { writer.Write(textSent.Text); } WebResponse response = request.GetResponse(); Stream stream = response.GetResponseStream(); string json = ""; using (StreamReader reader = new StreamReader(stream)) { while (!reader.EndOfStream) { json += reader.ReadLine(); } } txtResponse.Text = json; ParseLocation(json); IV. MOBILE AND WI-F I GEO LOCATION USING GOOGLE LATITUDE EXPERIMENTAL In this section we are introducing our system that is based on providing a new concept on Google latitude to prove that we can use the Wi-Fi information to define a device location without accessing GPS data on each query. This approach is currently possible since most the developed cities provide Wi-Fi service all around. This application can reduce a lot of energy consumption used on wireless mobile devices each time they are accessing the GPS data and connecting to the satellites’ signal. For the first step, we are going to use same steps as Google Latitude does for measuring the location. Instead, we are using Wi-Fi information data to measure the static tower locations. In our implementation, we are measuring each Wi-Fi tower position separately as shown in Figure 7. By measuring the WiFi relative location, we can also know the absolute device location.

Figure 7: Mobile and Wi-Fi Geo location scheme

In the Second step of our implementation, we need to have information like the device address and SSID stored in the server database. Accordingly, we do not need to access GPS data anymore. In case we need any location in a certain Wi-Fi network, we can approximately estimate the location of the device based on the static locations of three WI-FI towers. All this can be accomplished on a WI-FI network without accessing the GPS data. The user in an automated can update this information way if a new location is not yet stored on the database. Therefore, the device automatically sends the location information accessing the GPS data only once. The future quires of any other wireless mobile devices can define the location just by accessing the Wi-Fi network. V.

EXPERIMENT

The desktop-based application that is shown in Figure8 executes the queries based on Wi-Fi networks. We have made this application as a POC (proof of concept) that was explained in the previous section, and it is pretty simple. It works in two steps: 1. 2.

Get Wi-Fi data from PC. Send this information to Google and wait for response.

The first step is possible to access the Wi-Fi information using a useful programming library to in C#, which was shown in the system flow chart in Figure 6. However, if we turn on the laptop and then connect to Google Latitude, Google using the Wi-Fi towers information will detect Google using the Wi-Fi towers information. This also happens for the first instance we are using this application. Google measures the Wi-Fi data based on the GSM and GPS information. The developed application acts like this; since each user can detect his/her location then our application gets the information

for all the relative Wi-Fi towers and stores them in the database. The Second instance if the same user or another user wants to know any location close to this Wi-Fi tower, the user can access the application that will provide the user the absolute address. The novelty here is that we are not going to lose any energy for GPS access neither any synchronization time in trying to find the triangulation location of the Wi-Fi devices.

In this paper we introduced an important concept by implementing the methodology of Mobile and Wi-Fi Geo location Using Google Latitude. This approach could present itself as a new universally acceptable location service without having a huge cost to incur on the deployment, as Wi-Fi networks are already established. We are planning in the future to address the challenges presented in the previous section in order to successfully implement a Wi-Fi PS (Wi-Fi Positioning System). REFERENCES [1] Willaredt, Jonas. "WiFi and Cell-ID based positioning Protocols, Standards and Solutions." SNET Project WT (2011), 2011. [2] Hinden, Robert M. "IP next generation overview." Communications of the ACM 39, no. 6 (1996): 61-71. [3] Information Sciences Institute University of Southern California, “INTERNET PROTOCOL”, Defense Advanced Research Projects Agency, 1981. [4] M. Siegler, “While people worry about Facebook photos, a million users let Google know exactly where they are,” VentureBeat, Feb. 2009. [5] Pu, Chuan-Chin, Chuan-Hsian Pu, and Hoon-Jae Lee. "Indoor location tracking using received signal strength indicator." Emerging communications for wireless sensor networks (2011).

Figure 8: The application to calculate the absolute device location based on relative Wi-Fi data.

However, there are still some challenges for this concept to work without issues in the real world: 

Similar Wi-Fi names

There is no chronological order or a certain protocol that is followed in the naming conventions of the Wi-Fi networks. Therefore, it is difficult to recognize the different location on network name basis alone. 

Changing IP-addresses

The IP address frequently changes especially on Wi-Fi networks. It is important that we try to incorporate a methodology to have a list of MAC addresses for the various Wi-Fi routers 

Wi-Fi turning on/off

The Wi-Fi networks are not a standardized networks and the turning on and off of these networks is user controlled. That is if a user turns off a key Wi-Fi network, then the application can face some challenges in defining a location. Thus a key issue is the continuous broadcast of a Wi-Fi network. VI.

CONCLUSION

[6] Eddie C.L. Chan, George Baciu, S.C. Mak, “Orientationbased Wi-Fi Positioning on the Google Nexus One”, IEEE 6th international conference on wireless and mobile computing , networking and communication, 2010. [7] Denning, Dorothy E., and Peter F. MacDoran. "Locationbased authentication: Grounding cyberspace for better security." Computer Fraud & Security 1996, no. 2, 1996. [8] Capkun, Srdjan, and J-P. Hubaux. "Secure positioning of wireless devices with application to sensor networks." In INFOCOM 2005. 24th Annual Joint Conference of the IEEE Computer and Communications Societies. Proceedings IEEE, vol. 3, pp. 1917-1928. IEEE, 2005. [9] Y. Zhang, Z. Li, and W. Trappe. Power-Modulated Challenge-Response Schemes for Verifying LocationClaims. In Proc. of IEEE Globecom, Nov. 2007. [10] A. Tootoonchian, K. K. Gollu, S. Saroiu, Y. Ganjali, and A. Wolman. Lockr: Social Access Control for Web 2.0. In Proc. of the 1st ACM SIGCOMM Workshop on Online Social Networks (WOSN), Aug. 2008.