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The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation (2G) digital cellular networks used by mobile devices such as mobile phones and tablets. It was first deployed in Finland in December 1991. By the mid-2010s, it became a global standard for mobile communications achieving over 90% market share, and operating in over 193 countries and territories.
Time-division multiple access (TDMA) is a channel access method for shared-medium networks. It allows several users to share the same frequency channel by dividing the signal into different time slots. The users transmit in rapid succession, one after the other, each using its own time slot. This allows multiple stations to share the same transmission medium while using only a part of its channel capacity. Dynamic TDMA is a TDMA variant that dynamically reserves a variable number of time slots in each frame to variable bit-rate data streams, based on the traffic demand of each data stream.
The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP, UMTS is a component of the International Telecommunication Union IMT-2000 standard set and compares with the CDMA2000 standard set for networks based on the competing cdmaOne technology. UMTS uses wideband code-division multiple access (W-CDMA) radio access technology to offer greater spectral efficiency and bandwidth to mobile network operators.
A location-based service (LBS) is a general term denoting software services which use geographic data and information to provide services or information to users. LBS can be used in a variety of contexts, such as health, indoor object search, entertainment, work, personal life, etc. Commonly used examples of location based services include navigation software, social networking services, location-based advertising, and tracking systems. LBS can also include mobile commerce when taking the form of coupons or advertising directed at customers based on their current location. LBS also includes personalized weather services and even location-based games.
Enhanced 911, E-911 or E911 is a system used in North America to automatically provide the caller's location to 911 dispatchers. 911 is the universal emergency telephone number in the region. In the European Union, a similar system exists known as E112 and known as eCall when called by a vehicle.
The base station subsystem (BSS) is the section of a traditional cellular telephone network which is responsible for handling traffic and signaling between a mobile phone and the network switching subsystem. The BSS carries out transcoding of speech channels, allocation of radio channels to mobile phones, paging, transmission and reception over the air interface and many other tasks related to the radio network.
True-range multilateration is a method to determine the location of a movable vehicle or stationary point in space using multiple ranges (distances) between the vehicle/point and multiple spatially-separated known locations. The name is derived from trilateration, the geometrical problem of determining an unknown position on a plane based on the distance to other two known vertices of a triangle . True range multilateration is both a mathematical topic and an applied technique used in several fields. A practical application involving a fixed location is the trilateration method of surveying. Applications involving vehicle location are termed navigation when on-board persons/equipment are informed of its location, and are termed surveillance when off-vehicle entities are informed of the vehicle's location.
The 3110 is a GSM mobile phone handset manufactured by Nokia in Hungary, introduced at CEBIT in March 1997. The 3110 is notable as the first Nokia handset to feature the 'Navi-Key' menu navigation system. The Navi-Key was featured heavily on Nokia handsets, especially the entry-level models such as the Nokia 1100 in the following years. Unlike its successor, the 3210, and subsequent handsets of similar design, the 3110 had an external antenna. The phone was available with a slim, standard or vibrating battery. It could only be used on a GSM-900 network.
Mobile phone tracking is a process for identifying the location of a mobile phone, whether stationary or moving. Localization may be effected by a number of technologies, such as the multilateration of radio signals between (several) cell towers of the network and the phone or by simply using GNSS. To locate a mobile phone using multilateration of mobile radio signals, the phone must emit at least the idle signal to contact nearby antenna towers and does not require an active call. The Global System for Mobile Communications (GSM) is based on the phone's signal strength to nearby antenna masts.
Radiolocation, also known as radiolocating or radiopositioning, is the process of finding the location of something through the use of radio waves. It generally refers to passive uses, particularly radar—as well as detecting buried cables, water mains, and other public utilities. It is similar to radionavigation, but radiolocation usually refers to passively finding a distant object rather than actively one's own position. Both are types of radiodetermination. Radiolocation is also used in real-time locating systems (RTLS) for tracking valuable assets.
The angle of arrival (AoA) of a signal is the direction from which the signal is received.
A tracking system, also known as a locating system, is used for the observing of persons or objects on the move and supplying a timely ordered sequence of location data for further processing. It is important to be aware of human tracking, further details are listed below.
Tamara was the third generation Czechoslovak electronic support measures (ESM) system that used measurements of time difference of arrival (TDOA) of pulses at three or four sites to accurately detect and track airborne emitters by multilateration. Tamara's designations were KRTP-86 and KRTP-91 and it carried the NATO reporting name of Trash Can. The designation was derived from the Czech phrase "Komplet Radiotechnického Průzkumu" meaning "Radiotechnical Reconnaissance Set". It was claimed to be the only one in the world able to detect military "invisible aircraft".
Multilateration is a technique for determining a 'vehicle's' position based on measurement of the times of arrival (TOAs) of energy waves having a known waveform and speed when propagating either from (navigation) or to (surveillance) multiple system stations. These stations are at known locations and have synchronized 'clocks'. Prior to computing a solution, the time of transmission (TOT) of the waves is unknown to the receiver on the 'vehicle' (navigation) or the receivers at the stations (surveillance). Consequently, also unknown is the wave time of flight (TOF).
Sony Ericsson M600 is a 3G smartphone based upon the UIQ 3 platform. It was announced on February 6, 2006 and is the first and only product of the M series of handsets from Sony Ericsson.
Frequency difference of arrival (FDOA) or differential Doppler (DD), is a technique analogous to TDOA for estimating the location of a radio emitter based on observations from other points.. TDOA and FDOA are sometimes used together to improve location accuracy and the resulting estimates are somewhat independent. By combining TDOA and FDOA measurements, instantaneous geolocation can be performed in two dimensions.
Time of arrival is the absolute time instant when a radio signal emanating from a transmitter reaches a remote receiver. The time span elapsed since the time of transmission is the time of flight . Time difference of arrival (TDOA) is the difference between TOAs.
EGPS is a technology designed for mobile phones on GSM and W-CDMA networks, to augment GPS signals to deliver faster location fixes, lower cost implementations and reduced power and processing requirements. It is being developed by CSR who has partnered with Motorola – together they intend to create an open industry forum.
Radio resource location services (LCS) protocol (RRLP) applies to GSM and UMTS Cellular Networks. It is used to exchange messages between a handset and an SMLC in order to provide geolocation information; e.g., in the case of emergency calls. The protocol was developed in order to fulfil the Wireless Enhanced 911 requirements in the United States. However, since the protocol does not require any authentication, and it can be used outside a voice call or SMS transfer, its use is not restricted to emergency calls and can be used by law enforcement to pinpoint the exact geolocation of the target's mobile phone. RRLP was first specified in 3GPP TS 04.31 - Location Services (LCS); Mobile Station (MS) - Serving Mobile Location Centre (SMLC); Radio Resource LCS Protocol (RRLP).
Serving Mobile Location Center In GSM Networks, the SMLC is a network element that resides in the BSC and calculates network-based location of mobile stations (handsets). The SMLC may control several LMUs, which measure radio signals to help find mobile stations in the area served by the SMLC. It can calculate location using the TA method.
References
- ↑ “Overview of 2G LCS Technologies and Standards”
- ↑ “Testing E-ODT” (Manual for the E-ODT compliance check)
- ↑ “Mobile Phone Location Determination and Its Impact on Intelligent Transportation Systems” IEEE Transactions on Intelligent Transportation Systems. Vol 1, No. 1, pp 55 – 64, March, 2000.
- ↑ “Mobile location without network-based synchronization or How to do E-OTD without LMUs”. Proc. SPIE. Vol. 5084, 59 (2003).
- ↑ “Last Chance for E911 Technology”