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OTDOA
OTDOA (Observed Time Difference Of Arrival) is a positioning feature introduced in rel9 E-UTRA (LTE radio). It's a multilateration method in which the User Equipment (UE) measures the time difference between some specific signals from several eNodeBs and reports these time differences to a specific device in the network (the ESMLC). The ESMLC based on these time differences and knowledge of the enodeBs locations calculates the UEs' position. Background In December 2008, due to regulatory requirements like the E911, which require that it should be possible to locate UEs with a certain accuracy, a work item was proposed in the 3GPP TSG-RAN42 meeting. This proposed between others the study of the feasibility of OTDOA. OTDOA was meant to work in a similar way as the 3G IPL feature. During the summer of 2009 the necessary changes to the RAN1 36.211, 36.212, 36.213 and 36.214 specifications were accepted. And a bit later the RAN4 requirements and RAN2 protocol related matters settle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
E-UTRA
E-UTRA is the air interface of 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) upgrade path for mobile networks. It is an acronym for Evolved UMTS Terrestrial Radio Access, also known as the Evolved Universal Terrestrial Radio Access in early drafts of the 3GPP LTE specification. E-UTRAN is the combination of E-UTRA, user equipment (UE), and a Node B (E-UTRAN Node B or Evolved Node B, eNodeB). It is a radio access network (RAN) meant to be a replacement of the Universal Mobile Telecommunications System (UMTS), High-Speed Downlink Packet Access (HSDPA), and High-Speed Uplink Packet Access (HSUPA) technologies specified in 3GPP releases 5 and beyond. Unlike HSPA, LTE's E-UTRA is an entirely new air interface system, unrelated to and incompatible with W-CDMA. It provides higher data rates, lower latency and is optimized for packet data. It uses orthogonal frequency-division multiple access (OFDMA) radio-access for the downlink and single-carrier frequency-divis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LTE (telecommunication)
In telecommunications, long-term evolution (LTE) is a standard for wireless broadband communication for cellular mobile devices and data terminals. It is considered to be a "transitional" 4G technology, and is therefore also referred to as 3.95G as a step above 3G. LTE is based on the 2G GSM/ EDGE and 3G UMTS/ HSPA standards. It improves on those standards' capacity and speed by using a different radio interface and core network improvements. LTE is the upgrade path for carriers with both GSM/UMTS networks and CDMA2000 networks. LTE has been succeeded by LTE Advanced, which is officially defined as a "true" 4G technology and also named "LTE+". Terminology The standard is developed by the 3GPP (3rd Generation Partnership Project) and is specified in its Release 8 document series, with minor enhancements described in Release 9. LTE is also called 3.95G and has been marketed as 4G LTE and Advanced 4G; but the original version did not meet the technical criteria of a 4G wire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multilateration
Trilateration is the use of distances (or "ranges") for determining the unknown position coordinates of a point of interest, often around Earth ( geopositioning). When more than three distances are involved, it may be called multilateration, for emphasis. The distances or ranges might be ordinary Euclidean distances ( slant ranges) or spherical distances (scaled central angles), as in '' true-range multilateration''; or biased distances ( pseudo-ranges), as in '' pseudo-range multilateration''. Trilateration or multilateration should not be confused with '' triangulation'', which uses angles for positioning; and '' direction finding'', which determines the line of sight direction to a target without determining the radial distance. Terminology Multiple, sometimes overlapping and conflicting terms are employed for similar concepts – e.g., ''multilateration'' without modification has been used for aviation systems employing both true-ranges and pseudo-ranges."Multilatera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
User Equipment
In the Universal Mobile Telecommunications System (UMTS) and 3GPP Long Term Evolution (LTE), user equipment (UE) is any device used directly by an end-user to communicate. It can be a hand-held telephone, a laptop computer equipped with a mobile broadband adapter, or any other device. It connects to the base station Node B/eNodeB as specified in the ETSI 125/136-series and 3GPP 25/36-series of specifications. It roughly corresponds to the mobile station (MS) in GSM systems. The radio interface between the UE and the Node B is called ''Uu''. In the context of UMTS (Universal Mobile Telecommunications System), Uu stands for the interface between UTRAN (UMTS Terrestrial Radio Access Network) and the UE (User Equipment). Functionality UE handles the following tasks towards the core network: * Mobility management Mobility management is one of the major functions of a GSM or a UMTS network that allows mobile phones to work. The aim of mobility management is to track where the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SMLC
Serving Mobile Location Center In GSM The Global System for Mobile Communications (GSM) is a family of standards to describe the protocols for second-generation (2G) digital cellular networks, as used by mobile devices such as mobile phones and Mobile broadband modem, mobile broadba ... Networks, the SMLC is a network element that resides in the BSC (Base Station Controller) and calculates network-based location of mobile stations (handsets). The SMLC may control several LMUs (Location Measurement Units), which measure radio signals to help find mobile stations in the area served by the SMLC. It can calculate location using the TA (Timing Advance) method. The SMLC communicates with the GMLC, which is the interface to external LCS clients.GSM, GPRS and EDGE Performance - Second Edition p. 134 Notes GSM standard {{Compu-network-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
E911
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 (where 112 is the emergency access number) and known as eCall when called by a vehicle. An incoming 911 call is routed to a Public Safety Answering Point (PSAP), which is a call center operated by the local government. At the PSAP, the call is answered by a specially trained official known as a 9-1-1 dispatcher. The dispatcher's computer receives information from the telephone company about the physical address (for landlines) or geographic coordinates (for wireless) of the caller. This information is used to dispatch police, fire, medical and other services as needed. The planned replacement service is NG911. Call routing Landline routing Calls to 911 over the public switched telephone network (PSTN) are routed to a specia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3GPP
The 3rd Generation Partnership Project (3GPP) is an umbrella term for a number of standards organizations which develop protocols for mobile telecommunications. Its best known work is the development and maintenance of: * GSM and related 2G and 2.5G standards, including GPRS and EDGE * UMTS and related 3G standards, including HSPA and HSPA+ * LTE and related 4G standards, including LTE Advanced and LTE Advanced Pro * 5G NR and related 5G standards, including 5G-Advanced * An evolved IP Multimedia Subsystem (IMS) developed in an access independent manner 3GPP is a consortium with seven national or regional telecommunication standards organizations as primary members ("organizational partners") and a variety of other organizations as associate members ("market representation partners"). The 3GPP organizes its work into three different streams: Radio Access Networks, Services and Systems Aspects, and Core Network and Terminals. The project was established in Decembe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
