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Wednesday, January 22, 2014

Mobile phone tracking

Mobile phone tracking refers to the attaining of the current position of a mobile phone, stationary or moving. Localization may occur either via multilateration of radio signals between (several) radio towers of the network and the phone, or simply via GPS. To locate the phone using multilateration of radio signals, it must emit at least the roaming signal to contact the next nearby antenna tower, but the process does not require an active call. GSM is based on the signal strength to nearby antenna masts.

Mobile positioning, which includes location based service that discloses the actual coordinates of a mobile phone bearer, is a technology used by telecommunication companies to approximate the location of a mobile phone, and thereby also its user (bearer). The more properly applied term locating refers to the purpose rather than a positioning process. Such service is offered as an option of the class of location-based services (LBS).

Technology

The technology of locating is based on measuring power levels and antenna patterns and uses the concept that a powered mobile phone always communicates wirelessly with one of the closest base stations, so knowledge of the location of the base station implies the cell phone is nearby.

Advanced systems determine the sector in which the mobile phone resides and roughly estimate also the distance to the base station. Further approximation can be done by interpolating signals between adjacent antenna towers. Qualified services may achieve a precision of down to 50 meters in urban areas where mobile traffic and density of antenna towers (base stations) is sufficiently high. Rural and desolate areas may see miles between base stations and therefore determine locations less precisely.

GSM localization is the use of multilateration to determine the location of GSM mobile phones, or dedicated trackers, usually with the intent to locate the user.

Network-based

Network-based techniques utilize the service provider's network infrastructure to identify the location of the handset. The advantage of network-based techniques (from a mobile operator's point of view) is that they can be implemented non-intrusively, without affecting the handsets.

The accuracy of network-based techniques varies, with cell identification as the least accurate and triangulation as moderately accurate, and newer "Forward Link" timing methods as the most accurate. The accuracy of network-based techniques is both dependent on the concentration of base station cells, with urban environments achieving the highest possible accuracy, and the implementation of the most current timing methods.

One of the key challenges of network-based techniques is the requirement to work closely with the service provider, as it entails the installation of hardware and software within the operator's infrastructure. Often, a legislative framework, such as E911, would need to be in place to compel the cooperation of the service provider as well as to safeguard the privacy of the information.

Handset-based

Handset-based technology requires the installation of client software[5] on the handset to determine its location. This technique determines the location of the handset by putting its location by cell identification, signal strengths of the home and neighboring cells, which is continuously sent to the carrier. In addition, if the handset is also equipped with GPS then significantly more precise location information is then sent from the handset to the carrier.

The key disadvantage of this technique (from mobile operator's point of view) is the necessity of installing software on the handset. It requires the active cooperation of the mobile subscriber as well as software that must be able to handle the different operating systems of the handsets. Typically, smartphones, such as one based on Symbian, Windows Mobile, Windows Phone, BlackBerry OS, iOS, or Android, would be able to run such software. E.g. UonMap application.

One proposed work-around is the installation of embedded hardware or software on the handset by the manufacturers, e.g. E-OTD. This avenue has not made significant headway, due to the difficulty of convincing different manufacturers to cooperate on a common mechanism and to address the cost issue. Another difficulty would be to address the issue of foreign handsets that are roaming in the network.

SIM-based

Using the SIM in GSM and UMTS handsets, it is possible to obtain raw radio measurements from the handset. The measurements that are available can include the serving Cell ID, round trip time and signal strength. The type of information obtained via the SIM can differ from what is available from the handset. For example, it may not be possible to obtain any raw measurements from the handset directly, yet still obtain measurements via the SIM.

WiFi

Crowdsourced Wifi data can also be used to identify a handset's location. Poor performance of the GPS-based methods in indoor environment and increasing popularity of WiFi have encouraged companies to design new and feasible methods to carry out WiFi-based indoor positioning. Most smartphones combine GPS with Wi-Fi positioning systems.

Hybrid

Hybrid positioning systems use a combination of network-based and handset-based technologies for location determination. One example would be some modes of Assisted GPS, which can both use GPS and network information to compute the location. Both types of data are thus used by the telephone to make the location more accurate (i.e. A-GPS). Alternatively tracking with both systems can also occur by having the phone attain its GPS-location directly from the satellites, and then having the information sent via the network to the person that is trying to locate the telephone. Services allowing such cellphone include Google Latitude. Other examples would be LTE's OTDOA and E-CellID.

There are also hybrid positioning systems which combine several different location approaches to position mobile devices by WiFi, WiMAX, GSM, LTE, IP addresses, and network environment data.

Operational purpose

In order to route calls to a phone, the cell towers listen for a signal sent from the phone and negotiate which tower is best able to communicate with the phone. As the phone changes location, the antenna towers monitor the signal, and the phone is roamed to an adjacent tower as appropriate.
By comparing the relative signal strength from multiple antenna towers, a general location of a phone can be roughly determined. Other means make use of the antenna pattern, which supports angular determination and phase discrimination.

Newer phones may also allow the tracking of the phone even when turned on and not active in a telephone call. This results from the roaming procedures that perform hand-over of the phone from one base station to another.

Bearer interest

A phone's location can be uploaded to a common website where one's friends and family can view one's last reported position. Newer phones may have built-in GPS receivers which could be used in a similar fashion, but with much higher accuracy.
This may be controversial, because having this data on a common website may mean that people who are not 'friends and family' may be able to view the info, most obviously, the owners of the site.

Privacy

Locating or positioning touches upon delicate privacy issues, since it enables someone to check where a person is without the person's consent. Strict ethics and security measures are strongly recommended for services that employ positioning, and the user must give an informed, explicit consent to a service provider before the service provider can compute positioning data from the user's mobile phone.
In Europe, where most countries have a constitutional guarantee on the secrecy of correspondence, location data obtained from mobile phone networks is usually given the same protection as the communication itself. The United States, however, has no explicit constitutional guarantee on the privacy of telecommunications, so use of location data is limited by law.

Officially, the authorities (like the police) can obtain permission to position phones in emergency cases where people (including criminals) are missing. The U.S. Justice Department has argued that current laws allow them to track suspects without having probable cause to suspect a law is being violated. In some instances, law enforcement may even access a mobile phone's internal microphone to eavesdrop on local conversations while the phone is switched off.

The Electronic Frontier Foundation is tracking some cases, including USA v. Pen Register, regarding government tracking of individuals.
In the US, an interpretation of The Patriot Act that is secret, but confirmed to exist, has been linked to secret widespread location tracking.

China has proposed using this technology to track commuting patterns of Beijing city residents.Aggregate presence of mobile phone users could be tracked in a privacy-preserving fashion.


Cell Phone Detection

Had a cell phone detector been around, it would have picked up the world’s first ever cell phone call being placed in the dark ages of the twentieth century, a few months after the end of the Apollo moon program, before most people had heard of the Internet, and long before the invention of the World Wide Web. The date was April 3, 1973, and the device was a Motorola “brick” weighing more than four-and-one-half pounds and measuring some nine inches by five inches by one-and-three-quarter inches.

The dimensions of cell phones have shrunk dramatically in the intervening years, while their capabilities have grown exponentially, as has cell phone ownership. Their sophistication and ubiquity pose many security challenges, and have given rise to a demand for equally sophisticated cellular phone detection.

Cell phone detector applications

In addition to being able to make old-fashioned phone calls, today’s phones allow text messaging, photography, and recording and real-time transmission of audio and video. In short, they provide a wide variety of ways of recording and communicating information. In addition, the tiny size of modern phones makes them fiendishly difficult to detect if you are trying to prevent their introduction and use in a particular location. In many cases, it is simply not acceptable to pat down visitors and guests to make sure they are not secreting a phone on their person.


And there are plenty of times and places you might not want a cell phone to be used. They are a perfect tool for espionage, whether in military or government installations, or for industrial espionage. Security personnel at all such locations frequently deploy cell phone detection measures to assure the security of their information. In other circumstances, they can make possible various kinds of illegal activities, such as in prisons and other correctional institutions: a cell phone detector for prisons is a common application, for example. A mobile phone detector, or a network of them, can also be used to monitor for inappropriate transmissions in a casino, or to ensure that workers in a hazardous area are not using a cell phone that may distract them and cause an accident. These are just a few of the situations in which it is invaluable to deploy a mobile cell phone detector.

Wednesday, January 1, 2014

Latest Main Projects List For EE | Electrical Engineering - 2013


  1. Zigbee based obstacle sensing robot
  2. Zero sequence blocking transformer using three single phase transformers
  3. Vector control of 3 phase induction motor using double level vsi.
  4. Under ground cable fault detector
  5. Three phase fault detection
  6. Speed control of dc motor using radio frequency
  7. Speed control of dc motor using dc chopper
  8. Speed control of brushless dc motor
  9. Speed control and power factor improvement in induction motor
  10. Software for pnuematic system for hal - hybrid assistive limb
  11. Smart metering in smart grid
  12. Single phase inverter fed from fixed dc source
  13. Single phase five level inverter
  14. Simulation of upfc control
  15. Sign language translator
  16. Robotic arm with 4 degrees of freedom
  17. Multi-input dc boost converter for grid connected hybrid pv/fc/battery power system
  18. Modelling and control of rotary inverted pendulum
  19. Microcontroller based dc motor control
  20. Making a teaching kit using raspberry pi
  21. Low cost implementation of digital relays
  22. Load voltage regulation using vrs
  23. Micro grid power management
  24. Implementation of wavelet based ac motor fault detection using arm processor
  25. Harmonic filter
  26. Development of software package for sequential and synchronous operations of six motor drives.
  27. Development of advanced embedded system for home security using gsm
  28. Design a standby power supply across 220v mains
  29. Dc motor speed control using pic microcontroller
  30. Character and face recognition
  31. Brake fault detection for four wheeler
  32. Automatic control of hybrid bicycle
  33. Advanced ir remote control switch board
  34. Wireless energy meter