Automatic Vehile Location ( AVL )

Telecommunication devices with Automatic vehicle location technology (AVL or ~locating; telelocating in EU) is a means for automatically determining the geographic location of a vehicle and transmitting the information to a requester.

Most commonly, the location is determined using GPS, and the transmission mechanism is a satellite, terrestrial radio or cellular connection from the vehicle to a radio receiver, satellite or nearby cell tower. Other options for determining actual location, for example in environments where GPS illumination is poor, are dead reckoning, i.e. inertial navigation, or active RFID systems or cooperative RTLS systems. With advantage, combinations of these systems may be applied. In addition, terrestrial radio positioning systems utilizing an LF (Low Frequency) switched packet radio network were also used as an alternative to GPS based systems.

After capture, the tracking data is transmitted using any choice of telemetry or wireless communications systems. GSM and EVDO are the most common services applied, because of the low data rate needed for AVL, and the low cost and near-ubiquitous nature of these public networks. The low bandwidth requirements also allow for satellite technology to receive telemetry data at a moderately higher cost, but across a global coverage area and into very remote locations not covered well by terrestrial radio or public carriers. One system description discloses that locations are polled every thirty seconds.

Application with vehicles
Automatic vehicle locating is a powerful concept for managing fleets of vehicles, as service vehicles, emergency vehicles, and especially precious construction equipment, also public transport vehicles (buses and trains). It is also used to track mobile assets, such as non wheeled construction equipment, non motorized trailers, and mobile power generators.

Application with vehicle drivers and crews
The other purpose of tracking is to provide graded service or to manage a large driver and crewing staff effectively. For example, suppose an ambulance fleet has an objective of arriving at the location of a call for service within six minutes of receiving the request. Using an AVL system allows to evaluate the locations of all vehicles in service with driver and other crew in order to pick the vehicle that will most likely arrive at the destination fastest, (meeting the service objective).

Types of systems
Configurations
A typical AVL system would use terrestrial wireless communications already installed and then communicates simultaneously the locations of a vehicle to the manager of a fleet of vehicles.

Simple direction finding
Amateur radio and some cellular or PCS wireless systems use direction finding or triangulation of transmitter signals radiated by the mobile. This is sometimes called radio direction finding or RDF. The simplest forms of these systems calculate the bearing from two fixed sites to the mobile. This creates a triangle with endpoints at the two fixed points and the mobile. Trigonometry tells you roughly where the mobile transmitter is located. In wireless telephone systems, the phones transmit continually when off-hook, making continual tracking and the collection of many location samples possible. This is one type of location system required by Federal Communications Commission Rules for wireless Enhanced 911.

Former LORAN-based locating
Motorola offered a 1970s-era system based on the United States Coast Guard LORAN maritime navigation system. The LORAN system was intended for ships but signal levels on the US east- and west-coast areas were adequate for use with receivers in automobiles. The system may have been marketed under the Motorola model name Metricom. It consisted of an LF LORAN receiver and data interface box/modem connected to a separate two-way radio. The receiver and interface calculated a latitude and longitude in degrees, decimal degrees format based on the LORAN signals. This was sent over the radio as MDC-1200 or MDC-4800 data to a system controller, which plotted the mobile's approximate location on a map. The system worked reliably but sometimes had problems with electrical noise in urban areas. Sparking electric trolley poles or industrial plants which radiated electrical noise sometime overwhelmed the LORAN signals, affecting the system's ability to determine the mobile's geolocation. Because of the limited resolution, this type of system was impractical for small communities or operational areas such as a pit mine or port.

Signpost systems
To track and locate vehicles along fixed routes, a technology called Signpost transmitters is employed. This is used on transit routes and rail lines where the vehicles to be tracked continually operated on the same linear route. A transponder or RFID chip along the vehicle route would be polled as the train or bus traverses its route. As each transponder was passed, the moving vehicle would query and receive an ack, or handshake, from the signpost transmitter. A transmitter on the mobile would report passing the signpost to a system controller. This allows supervision, a call center, or a dispatch center to monitor the progress of the vehicle and assess whether or not the vehicle was on schedule. These systems are an alternative inside tunnels or other conveyances where GPS signals are blocked by terrain.

Today's GPS-based locating
The low price and ubiquity of Global Positioning System or GPS equipment has lent itself to more accurate and reliable telelocation systems. GPS signals are impervious to most electrical noise sources and don't require the user to install an entire system. Only a receiver to collect signals from the satellite segment is installed in each vehicle and a radio to communicate the collected location data with a dispatch point.

Large private telelocation or AVL systems send data from GPS receivers in vehicles to a dispatch center over their private, user-owned radio backbone. These systems are used for businesses like parcel delivery and ambulances. Smaller systems which don't justify building a separate radio system use cellular or PCS data services to communicate location data from vehicles to their dispatching center. Location data is periodically polled from each vehicle in a fleet by a central controller or computer. In the simplest systems, data from the GPS receiver is displayed on a map allowing humans to determine the location of each vehicle. More complex systems feed the data into a computer assisted dispatch system which automates the process. For example, the computer assisted dispatch system may check the location of a call for service and then pick a list of the four closest ambulances. This narrows the dispatcher's choice from the entire fleet to an easier choice of four vehicles.

Some wireless carriers such as Nextel have decided GPS was the best way to provide the mandated location data for wireless Enhanced 9-1-1. Newer Nextel radios have embedded GPS receivers which are polled if 9-1-1 is dialed. The 9-1-1 center is provided with latitude and longitude from the radio's GPS receiver. In centers with computer assisted dispatch, the system may assign an address to the call based on these coordinates or may project an icon depicting the caller's location onto a map of the area.

Sensor-augmented AVL
The main purpose of using AVL is not only to locate the vehicles, but also to obtain information about engine data, fuel consumption, driver data and sensor data from i.e. doors, freezer room on trucks or air pressure. Such data can be obtained via the CAN-bus, via direct connections to AVL systems or via open bus systems such as UFDEX that both sends and receives data via SMS or GPRS in pure ASCII text format. Because most AVL consists of two parts, GPS and GSM modem with additional embedded AVL software contained in a microcontroller, most AVL systems are fixed for its purposes unless they connect to an open bus system for expansion possibilities.

With an open bus system the users can send invoices based on goods delivered with exact location, time and date data where if connected to scale, RFID or barcode readers, can make a fairly good automated system to avoid human errors.

Logbook functions
Another scenario for sensor functions is to connect the AVL to driver information, to collect data about driving time, stops, or even driver absence from the vehicle. If the driver/worker conditions is such as the hourly rates for driving and working outside is not the same, this can be monitored by sensors.[needs clarification]

Differentiating between Automatic Vehicle Location and Events Activated Tracking Systems
It might be helpful to draw a distinction between vehicle location systems which track automatically and vehicle location systems which track when triggered by an event. There is increasingly crossover between the different systems and those with experience of this sector will be able to draw on a number of examples which break the rule.

A.V.L (Automatic Vehicle Location) This type of vehicle tracking is normally used in the fleet or driver management sector. The unit is configured to automatically transmit it’s location at a set time interval, e.g. every 5 minutes. The unit is activated when the ignition is switched on/off.

E.A.T.S (Events Activated Tracking system) This type of system is primarily used in connection with vehicle or driver security solutions. If, for example a thief breaks into your car and attempts to steal it, the tracking system can be triggered by the immobiliser unit or motion sensor being activated. A monitoring bureau, will then be automatically notified that the unit has been activated and begin tracking the vehicle.

Some products on the market are a hybrid of both AVL and EATS technology. However industry practice has tended to lean towards a separation of these functions. It is worth taking note that vehicle tracking products tend to fall in to one, not both of the technologies.

AVL technology is predominately used when applying vehicle tracking to fleet or driver management solutions. The use of Automatic Vehicle Location is given in the following scenario; A car breaks down by the side of the road and the occupant calls a vehicle recovery company. The vehicle recovery company has several vehicles operating in the area. Without needing to call each driver to check his location the dispatcher can pinpoint the nearest recovery vehicle and assign it to the new job. If you were to incorporate the other aspects of vehicle telematics into this scenario; the dispatcher, rather than phoning the recovery vehicle operative, could transmit the job details directly to the operative’s mobile data device, who would then use the in-vehicle satellite navigation to aid his journey to the job.

EATS technology is predominately used when applying vehicle tracking to vehicle security solutions. An example of this distinction is given in the following scenario; A construction company owns some pieces of plant machinery that are regularly left unattended, at weekends, on building sites. Thieves break onto one site and a piece equipment, such as a digger, is loaded on the back of a flat bed truck and then driven away. Typically the ignition wouldn’t need to be turned on and as such most of the AVL products available wouldn’t typically be activated. Only products that included a unit that was activated by a motion sensor or GeoFence alarm event, would be activated.
Both AVL and EATS systems track, but often for different purposes.

Special applications of automatic vehicle locating
Vehicle location technologies can be used in the following scenarios:

• Fleet management: when managing a fleet of vehicles, knowing the real-time location of all drivers allows management to meet customer needs more efficiently. Vehicle location information can also be used to verify that legal requirements are being met: for example, that drivers are taking rest breaks and obeying speed limits.
• Passenger Information: Real-time Passenger information systems use predictions based on AVL input to show the expected arrival and departure times of Public Transport services.
• Asset tracking: companies needing to track valuable assets for insurance or other monitoring purposes can now plot the real-time asset location on a map and closely monitor movement and operating status. For example, haulage and logistics companies often operate trucks with detachable load carrying units. In this case, trailers can be tracked independently of the cabs used to drive them. Combining vehicle location with inventory management that can be used to reconcile which item is currently on which vehicle can be used to identify physical location down to the level of individual packages.
• Field worker management: companies with a field service or sales workforce can use information from vehicle tracking systems to plan field workers' time, schedule subsequent customer visits and be able to operate these departments efficiently.
• Covert surveillance: vehicle location devices attached covertly by law enforcement or espionage organizations can be used to track journeys made by individuals who are under surveillance ( source : http://en.wikipedia.org/wiki/Automatic_vehicle_location )
  

In Indonesia telecommunication devices. AVL LT-05/TZ-AVL 05 has been tested by Indonesia test house, and has been issued type approval certification by DGPT.

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VSAT | Very Small Aperture Terminal

Telecommunication devices Very Small Aperture Terminal ( VSAT ), is a two-way satellite ground station or a stabilized maritime Vsat antenna with a dish antenna that is smaller than 3 meters. The majority of VSAT antennas range from 75 cm to 1.2 m. Data rates typically range from 56 Kbit/s up to 4 Mbit/s. VSATs access satellites in geosynchronous orbit to relay data from small remote earth stations (terminals) to other terminals (in mesh configurations) or master earth station "hubs" (in star configurations).

VSATs are most commonly used to transmit narrowband data (point of sale transactions such as credit card, polling or RFID data; or SCADA), or broadband data (for the provision of Satellite Internet access to remote locations, VoIP or video). VSATs are also used for transportable, on-the-move (utilising phased array antennas) or mobile maritime communications.

Configurations
Most VSAT networks are configured in one of these topologies:

• A star topology, using a central uplink site, such as a network operations center (NOC), to transport data back and forth to each VSAT terminal via satellite,
• A mesh topology, where each VSAT terminal relays data via satellite to another terminal by acting as a hub, minimizing the need for a centralized uplink site,
• A combination of both star and mesh topologies. Some VSAT networks are configured by having several centralized uplink sites (and VSAT terminals stemming from it) connected in a multi-star topology with each star (and each terminal in each star) connected to each other in a mesh topology. Others configured in only a single star topology sometimes will have each terminal connected to each other as well, resulting in each terminal acting as a central hub. These configurations are utilized to minimize the overall cost of the network, and to alleviate the amount of data that has to be relayed through a central uplink site (or sites) of a star or multi-star network.
  

Future applications
Advances in technology have dramatically improved the price/performance equation of FSS (Fixed Service Satellite) over the past five years. New VSAT systems are coming online using Ka band technology that promise higher bandwidth rates for lower costs.

FSS satellite systems currently in orbit have a huge capacity with a relatively low price structure. FSS satellite systems provide various applications for subscribers, including: telephony, fax, television, high speed data communication services, Internet access, Satellite News Gathering (SNG), Digital Audio Broadcasting (DAB) and others. These systems are applicable for providing various high-quality services because they create efficient communication systems, both for residential and business users.

Constituent parts of a VSAT configuration

• Antenna :is a transducer designed to transmit or receive electromagnetic waves. In other words, antennas convert electromagnetic radiation into electrical current, or vice versa. Antennas generally deal in the transmission and reception of radio waves, and are a necessary part of all radio equipment. Antennas are used in systems such as radio and television broadcasting, point-to-point radio communication, wireless LAN, cell phones, radar, and spacecraft communication. Antennas are most commonly employed in air or outer space, but can also be operated under water or even through soil and rock at certain frequencies for short distances.
• Block upconverter (BUC) : A block upconverter (BUC) is used in the transmission (uplink) of satellite signals. It converts a band (or "block") of frequencies from a lower frequency to a higher frequency. Modern BUCs convert from the L band to Ku band, C band and Ka band. Older BUCs convert from a 70 MHz intermediate frequency (IF) to Ku band or C band.
• Low-noise block converter (LNB) : A low-noise block converter (LNB, for low-noise block, sometimes LNC, for low-noise converter, or, rarely, LND for low-noise downconverter) is the (receiving, or downlink) antenna of what is commonly called the parabolic satellite dish commonly used for satellite TV reception. It is functionally equivalent to the dipole antenna used for most other TV reception purposes, although it is actually waveguide based. Whereas the dipole antenna is unable to adapt itself to various polarization planes without being rotated, the LNB can be switched electronically between horizontal and vertical polarization reception. The LNB is usually fixed on or in the satellite dish, for the reasons outlined below. The corresponding component in the uplink transmit link is called a Block upconverter (BUC).
• Orthomode transducer (OMT) : An orthomode transducer is a microwave duct component of the class of microwave circulators. It is commonly referred to as an OMT, and commonly referred as a polarisation duplexer. Such device may be part of a VSAT antenna feed Orthomode transducers serve either to combine or to separate two microwave signal paths. One of the paths forms the uplink, which is transmitted over the same waveguide as the received signal path or downlink path. For VSAT modems the transmission and reception paths are at 90° to each other, or in other words, the signals are orthogonally polarised with respect to each other. This orthogonal shift between the two signal paths provides approximately an isolation of 40dB in the Ku band and Ka band radio frequency bands.
• Interfacility Link Cable (IFL) :
• Indoor unit (IDU)
  

All the outdoor parts on the dish are collectively called the ODU (Outdoor Unit), i.e. OMT to split signal between BUC and LNB. The IDU is effectively a Modem, usually with ethernet port and 2 x F-connectors for the coax to BUC(Transmit) and from LNB (Receive). The Astra2Connect has an all-in-one OMT/BUC/LNA that looks like a QUAD LNB in shape and size which mounts on a regular TV sat mount. As a consequence it is only 500 mW compared with the normal 2W, thus is poorer in rain. ( Source : http://en.wikipedia.org/wiki/Very_small_aperture_terminal )

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Wireless Lokal Area Network | WLAN

A wireless local area network (WLAN) links devices via a wireless distribution method (typically spread-spectrum or OFDM) and usually provides a connection through an access point to the wider Internet. This gives users the mobility to move around within a local coverage area and still be connected to the network.

Wireless LANs have become popular in the home due to ease of installation and the increasing popularity of laptop computers. Public businesses such as coffee shops and malls have begun to offer wireless access to their customers, sometimes for free. Large wireless network projects are being put up in many major cities: New York City, for instance, has begun a pilot program to cover all five boroughs of the city with wireless Internet access.

History
In 1970, Norman Abramson, a professor at the University of Hawaii, developed the world’s first computer communication network, ALOHAnet, using low-cost ham-like radios. With a bi-directional star topology, the system connected seven computers deployed over four islands to communicate with the central computer on the Oahu Island without using phone lines.

"In 1979, F.R. Gfeller and U. Bapst published a paper in the IEEE Proceedings reporting an experimental wireless local area network using diffused infrared communications. Shortly thereafter, in 1980, P. Ferrert reported on an experimental application of a single code spread spectrum radio for wireless terminal communications in the IEEE National Telecommunications Conference. In 1984, a comparison between infrared and CDMA spread spectrum communications for wireless office information networks was published by Kaveh Pahlavan in IEEE Computer Networking Symposium which appeared later in the IEEE Communication Society Magazine. In May 1985, the efforts of Marcus led the FCC to announce experimental ISM bands for commercial application of spread spectrum technology. Later on, M. Kavehrad reported on an experimental wireless PBX system using code division multiple access. These efforts prompted significant industrial activities in the development of a new generation of wireless local area networks and it updated several old discussions in the portable and mobile radio industry.

The first generation of wireless data modems was developed in the early 1980s by amateur radio operators, who commonly referred to this as packet radio. They added a voice band data communication modem, with data rates below 9600-bit/s, to an existing short distance radio system, typically in the two meter amateur band. The second generation of wireless modems was developed immediately after the FCC announcement in the experimental bands for non-military use of the spread spectrum technology. These modems provided data rates on the order of hundreds of kbit/s. The third generation of wireless modem then aimed at compatibility with the existing LANs with data rates on the order of Mbit/s. Several companies developed the third generation products with data rates above 1 Mbit/s and a couple of products had already been announced by the time of the first IEEE Workshop on Wireless LANs.

The first of the IEEE Workshops on Wireless LAN was held in 1991. At that time early wireless LAN products had just appeared in the market and the IEEE 802.11 committee had just started its activities to develop a standard for wireless LANs. The focus of that first workshop was evaluation of the alternative technologies. By 1996, the technology was relatively mature, a variety of applications had been identified and addressed and technologies that enable these applications were well understood. Chip sets aimed at wireless LAN implementations and applications, a key enabling technology for rapid market growth, were emerging in the market. Wireless LANs were being used in hospitals, stock exchanges, and other in building and campus settings for nomadic access, point-to-point LAN bridges, ad-hoc networking, and even larger applications through Internetworking. The IEEE 802.11 standard and variants and alternatives, such as the wireless LAN interoperability forum and the European HiperLAN specification had made rapid progress, and the unlicensed PCS Unlicensed Personal Communications Services and the proposed SUPERNet, later on renamed as U-NII, bands also presented new opportunities.

WLAN hardware was initially so expensive that it was only used as an alternative to cabled LAN in places where cabling was difficult or impossible. Early development included industry-specific solutions and proprietary protocols, but at the end of the 1990s these were replaced by standards, primarily the various versions of IEEE 802.11 (Wi-Fi). An alternative ATM-like 5 GHz standardized technology, HiperLAN/2, has so far not succeeded in the market, and with the release of the faster 54 Mbit/s 802.11a (5 GHz) and 802.11g (2.4 GHz) standard

Architecture

Stations
All components that can connect into a wireless medium in a network are referred to as stations.
All stations are equipped with wireless network interface cards (WNICs).
Wireless stations fall into one of two categories: access points and clients.
Access points (APs), normally routers, are base stations for the wireless network. They transmit and receive radio frequencies for wireless enabled devices to communicate with.

Wireless clients can be mobile devices such as laptops, personal digital assistants, IP phones, or fixed devices such as desktops, laptops, and workstations that are equipped with a wireless network interface.

Basic service set
The basic service set (BSS) is a set of all stations that can communicate with each other.
There are two types of BSS: Independent BSS (also referred to as IBSS) and infrastructure BSS.
Every BSS has an identification (ID) called the BSSID, which is the MAC address of the access point servicing the BSS.
An independent BSS (IBSS) is an ad-hoc network that contains no access points, which means they can not connect to any other basic service set.
An infrastructure can communicate with other stations not in the same basic service set by communicating through access points.

Extended service set
An extended service set (ESS) is a set of one or more interconnected BSSes. Access points in an ESS are connected by a distribution system. Each ESS has an ID called the SSID which is a 32-byte (maximum) character string.

Distribution system
A distribution system (DS) connects access points in an extended service set. The concept of a DS can be used to increase network coverage through roaming between cells.

Types of wireless LANs

Peer-to-peer
An ad-hoc network is a network where stations communicate only peer to peer (P2P). There is no base and no one gives permission to talk. This is accomplished using the Independent Basic Service Set (IBSS).

A peer-to-peer (P2P) network allows wireless devices to directly communicate with each other. Wireless devices within range of each other can discover and communicate directly without involving central access points. This method is typically used by two computers so that they can connect to each other to form a network.

If a signal strength meter is used in this situation, it may not read the strength accurately and can be misleading, because it registers the strength of the strongest signal, which may be the closest computer.

IEEE 802.11 define the physical layer (PHY) and MAC (Media Access Control) layers based on CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance). The 802.11 specification includes provisions designed to minimize collisions, because two mobile units may both be in range of a common access point, but out of range of each other.

The 802.11 has two basic modes of operation: Ad hoc mode enables peer-to-peer transmission between mobile units. Infrastructure mode in which mobile units communicate through an access point that serves as a bridge to a wired network infrastructure is the more common wireless LAN application the one being covered. Since wireless communication uses a more open medium for communication in comparison to wired LANs, the 802.11 designers also included shared-key encryption mechanisms: Wired Equivalent Privacy (WEP) and Wi-Fi Protected Access (WPA, WPA2) to secure wireless computer networks.

Bridge
A bridge can be used to connect networks, typically of different types. A wireless Ethernet bridge allows the connection of devices on a wired Ethernet network to a wireless network. The bridge acts as the connection point to the Wireless LAN.

Wireless distribution system
A Wireless Distribution System is a system that enables the wireless interconnection of access points in an IEEE 802.11 network. It allows a wireless network to be expanded using multiple access points without the need for a wired backbone to link them, as is traditionally required. The notable advantage of WDS over other solutions is that it preserves the MAC addresses of client packets across links between access points.

An access point can be either a main, relay or remote base station. A main base station is typically connected to the wired Ethernet. A relay base station relays data between remote base stations, wireless clients or other relay stations to either a main or another relay base station. A remote base station accepts connections from wireless clients and passes them to relay or main stations. Connections between "clients" are made using MAC addresses rather than by specifying IP assignments.

All base stations in a Wireless Distribution System must be configured to use the same radio channel, and share WEP keys or WPA keys if they are used. They can be configured to different service set identifiers. WDS also requires that every base station be configured to forward to others in the system.

WDS may also be referred to as repeater mode because it appears to bridge and accept wireless clients at the same time (unlike traditional bridging). It should be noted, however, that throughput in this method is halved for all clients connected wirelessly.

When it is difficult to connect all of the access points in a network by wires, it is also possible to put up access points as repeaters.

Roaming
There are 2 definitions for wireless LAN roaming:

• Internal Roaming (1): The Mobile Station (MS) moves from one access point (AP) to another AP within a home network because the signal strength is too weak. An authentication server (RADIUS) assumes the re-authentication of MS via 802.1x (e.g. with PEAP). The billing of QoS is in the home network. A Mobile Station roaming from one access point to another often interrupts the flow of data between the Mobile Station and an application connected to the network. The Mobile Station, for instance, periodically monitors the presence of alternative access points (ones that will provide a better connection). At some point, based upon proprietary mechanisms, the Mobile Station decides to re-associate with an access point having a stronger wireless signal. The Mobile Station, however, may lose a connection with an access point before associating with another access point. In order to provide reliable connections with applications, the Mobile Station must generally include software that provides session persistence.
• External Roaming (2): The MS (client) moves into a WLAN of another Wireless Internet Service Provider (WISP) and takes their services (Hotspot). The user can independently of his home network use another foreign network, if this is open for visitors. There must be special authentication and billing systems for mobile services in a foreign network.

( Source : http://en.wikipedia.org/wiki/Wireless_LAN )

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Bluetooth Technology

Every telecommunication device that uses bluetooth technology as one of the features of the operation of such devices and these devices are assembled and in the marketed in Indonesia. such devices mandatory for certification according to procedure bluetooth in Indonesia.

Bluetooth is a proprietary open wireless technology standard for exchanging data over short distances (using short length radio waves) from fixed and mobile devices, creating personal area networks (PANs) with high levels of security. Invented by telecoms vendor Ericsson in 1994, it was originally conceived as a wireless alternative to RS-232 data cables. It can connect several devices, overcoming problems of synchronization. Today Bluetooth is managed by the Bluetooth Special Interest Group.

Name and logo
The word Bluetooth is an anglicised version of Danish Blåtand, the epithet of the tenth-century king Harald I of Denmark and parts of Norway who united dissonant Danish tribes into a single kingdom. The implication is that Bluetooth does the same with communications protocols, uniting them into one universal standard. Although blå in modern Scandinavic languages means blue, during the Viking age it also could mean black. So a historically correct translation of Old Norse Harald Blátönn could rather be Harald Blacktooth than Harald Bluetooth.

The Bluetooth logo is a bind rune merging the Germanic runes H-rune.gif (Hagall) and Runic letter berkanan.svg (Berkanan).

Implementation
Bluetooth uses a radio technology called frequency-hopping spread spectrum, which chops up the data being sent and transmits chunks of it on up to 79 bands of 1 MHz width in the range 2402-2480 MHz. This is in the globally unlicensed Industrial, Scientific and Medical (ISM) 2.4 GHz short-range radio frequency band.

In Classic Bluetooth, which is also referred to as basic rate (BR) mode, the modulation is Gaussian frequency-shift keying (GFSK). It can achieve a gross data rate of 1 Mbit/s. In extended data rate (EDR) π/4-DQPSK and 8DPSK are used, giving 2, and 3 Mbit/s respectively.

Bluetooth is a packet-based protocol with a master-slave structure. One master may communicate with up to 7 slaves in a piconet; all devices share the master's clock. Packet exchange is based on the basic clock, defined by the master, which ticks at 312.5 µs intervals. Two clock ticks make up a slot of 625 µs; two slots make up a slot pair of 1250 µs. In the simple case of single-slot packets the master transmits in even slots and receives in odd slots; the slave, conversely, receives in even slots and transmits in odd slots. Packets may be 1, 3 or 5 slots long but in all cases the master transmit will begin in even slots and the slave transmit in odd slots.

Bluetooth provides a secure way to connect and exchange information between devices such as faxes, mobile phones, telephones, laptops, personal computers, printers, Global Positioning System (GPS) receivers, digital cameras, and video game consoles.

The Bluetooth specifications are developed and licensed by the Bluetooth Special Interest Group (SIG). The Bluetooth SIG consists of more than 13,000 companies in the areas of telecommunication, computing, networking, and consumer electronics.
To be marketed as a Bluetooth device, it must be qualified to standards defined by the SIG.

Communication and connection
A master Bluetooth device can communicate with up to seven devices in a Wireless User Group. This network group of up to eight devices is called a piconet. The devices can switch roles, by agreement, and the slave can become the master at any time.
At any given time, data can be transferred between the master and one other device.

The master switches rapidly from one device to another in a round-robin fashion. Simultaneous transmission from the master to multiple other devices is possible via broadcast mode, but not used much.

The Bluetooth Core Specification allows connecting two or more piconets together to form a scatternet, with some devices acting as a bridge by simultaneously playing the master role in one piconet and the slave role in another.

Many USB Bluetooth adapters or "dongles" are available, some of which also include an IrDA adapter. Older (pre-2003) Bluetooth dongles, however, have limited services, offering only the Bluetooth Enumerator and a less-powerful Bluetooth Radio incarnation. Such devices can link computers with Bluetooth, but they do not offer much in the way of services that modern adapters do.

Uses
Bluetooth is a standard communications protocol primarily designed for low power consumption, with a short range (power-class-dependent: 100 m, 10 m and 1 m, but ranges vary in practice; see table below) based on low-cost transceiver microchips in each device.[6] Because the devices use a radio (broadcast) communications system, they do not have to be in line of sight of each other.

• Class 1 : Maximum Permitted Power 100 mW, 20 dBm, Range(approximate) ~100 meters
• Class 2 : Maximum Permitted Power 2.5 mW, 4 dBm, Range( approximate) ~10 meters
• Class 3 : Maximum Permitted Power 1 mW, 0 dBm, Range (approximate) ~1 meters
  

In most cases the effective range of class 2 devices is extended if they connect to a class 1 transceiver, compared to a pure class 2 network. This is accomplished by the higher sensitivity and transmission power of Class 1 devices.

• Version 1.2 Data rate 1 Mbit/s
• Version 2.0 + EDR Data rate 3 Mbit/s
• Version 3.0 + HS Data rate 24 Mbit/s
  

While the Bluetooth Core Specification does mandate minimums for range, the range of the technology is application specific and is not limited. Manufacturers may tune their implementations to the range needed to support individual use cases.

Specifications and features
The Bluetooth specification was developed in 1994 by Jaap Haartsen and Sven Mattisson, who were working for Ericsson in Lund, Sweden. The specification is based on frequency-hopping spread spectrum technology.

The specifications were formalized by the Bluetooth Special Interest Group (SIG). The SIG was formally announced on May 20, 1998. Today it has a membership of over 13,000 companies worldwide. It was established by Ericsson, IBM, Intel, Toshiba, and Nokia, and later joined by many other companies.

Bluetooth v1.0 and v1.0B
Versions 1.0 and 1.0B had many problems, and manufacturers had difficulty making their products interoperable. Versions 1.0 and 1.0B also included mandatory Bluetooth hardware device address (BD_ADDR) transmission in the Connecting process (rendering anonymity impossible at the protocol level), which was a major setback for certain services planned for use in Bluetooth environments.

Bluetooth v1.1

• Ratified as IEEE Standard 802.15.1-2002
• Many errors found in the 1.0B specifications were fixed.
• Added support for non-encrypted channels.
• Received Signal Strength Indicator (RSSI).
  

Bluetooth v1.2
This version is backward compatible with 1.1 and the major enhancements include the following:

• Faster Connection and Discovery
• Adaptive frequency-hopping spread spectrum (AFH), which improves resistance to radio frequency interference by avoiding the use of crowded frequencies in the hopping sequence.
• Higher transmission speeds in practice, up to 721 kbit/s[citation needed], than in 1.1.
• Extended Synchronous Connections (eSCO), which improve voice quality of audio links by allowing retransmissions of corrupted packets, and may optionally increase audio latency to provide better support for concurrent data transfer.
• Host Controller Interface (HCI) support for three-wire UART.
• Ratified as IEEE Standard 802.15.1-2005.
• Introduced Flow Control and Retransmission Modes for L2CAP.
  

Bluetooth v2.0 + EDR
This version of the Bluetooth Core Specification was released in 2004 and is backward compatible with the previous version 1.2. The main difference is the introduction of an Enhanced Data Rate (EDR) for faster data transfer. The nominal rate of EDR is about 3 megabits per second, although the practical data transfer rate is 2.1 megabits per second. EDR uses a combination of GFSK and Phase Shift Keying modulation (PSK) with two variants, π/4-DQPSK and 8DPSK [22]. EDR can provide a lower power consumption through a reduced duty cycle.

The specification is published as "Bluetooth v2.0 + EDR" which implies that EDR is an optional feature. Aside from EDR, there are other minor improvements to the 2.0 specification, and products may claim compliance to "Bluetooth v2.0" without supporting the higher data rate. At least one commercial device states "Bluetooth v2.0 without EDR" on its data sheet

Bluetooth v2.1 + EDR
Bluetooth Core Specification Version 2.1 + EDR is fully backward compatible with 1.2, and was adopted by the Bluetooth SIG on July 26, 2007.

The headline feature of 2.1 is secure simple pairing (SSP): this improves the pairing experience for Bluetooth devices, while increasing the use and strength of security. See the section on Pairing below for more details.

2.1 allows various other improvements, including "Extended inquiry response" (EIR), which provides more information during the inquiry procedure to allow better filtering of devices before connection; sniff subrating, which reduces the power consumption in low-power mode

Bluetooth v3.0 + HS
Version 3.0 + HS of the Bluetooth Core Specification[22] was adopted by the Bluetooth SIG on April 21, 2009. It supports theoretical data transfer speeds of up to 24 Mbit/s, though not over the Bluetooth link itself. Instead, the Bluetooth link is used for negotiation and establishment, and the high data rate traffic is carried over a colocated 802.11 link. Its main new feature is AMP (Alternate MAC/PHY), the addition of 802.11 as a high speed transport. Two technologies had been anticipated for AMP: 802.11 and UWB, but UWB is missing from the specification.

Alternate MAC/PHY

• Enables the use of alternative MAC and PHYs for transporting Bluetooth profile data. The Bluetooth radio is still used for device discovery, initial connection and profile configuration, however when large quantities of data need to be sent, the high speed alternate MAC PHY 802.11 (typically associated with Wi-Fi) will be used to transport the data. This means that the proven low power connection models of Bluetooth are used when the system is idle, and the low power per bit radios are used when large quantities of data need to be sent.
  

Unicast connectionless data

• Permits service data to be sent without establishing an explicit L2CAP channel. It is intended for use by applications that require low latency between user action and reconnection/transmission of data. This is only appropriate for small amounts of data.
  

Enhanced Power Control

• Updates the power control feature to remove the open loop power control, and also to clarify ambiguities in power control introduced by the new modulation schemes added for EDR. Enhanced power control removes the ambiguities by specifying the behaviour that is expected. The feature also adds closed loop power control, meaning RSSI filtering can start as the response is received. Additionally, a "go straight to maximum power" request has been introduced, this is expected to deal with the headset link loss issue typically observed when a user puts their phone into a pocket on the opposite side to the headset.
  

Bluetooth v4.0
On June 12, 2007, Nokia and Bluetooth SIG had announced that Wibree will be a part of the Bluetooth specification, as an ultra-low power Bluetooth technology.[26]

On December 17, 2009, the Bluetooth SIG adopted Bluetooth low energy technology as the hallmark feature of the version 4.0.[27] The provisional names Wibree and Bluetooth ULP (Ultra Low Power) are abandoned.

On April 21, 2010, the Bluetooth SIG completed the Bluetooth Core Specification version 4.0, which includes Classic Bluetooth, Bluetooth high speed and Bluetooth low energy protocols. Bluetooth high speed is based on Wi-Fi, and Classic Bluetooth consists of legacy Bluetooth protocols.

Bluetooth low energy
Bluetooth low energy is a recent enhancement that allows two types of implementation, dual-mode and single-mode. In a dual-mode implementation, Bluetooth low energy functionality is integrated into an existing Classic Bluetooth controller. The resulting architecture shares much of Classic Bluetooth’s existing radio and functionality resulting in a minimal cost increase compared to Classic Bluetooth. Additionally, manufacturers can use current Classic Bluetooth (Bluetooth V2.1 + EDR or Bluetooth V3.0 + HS) chips with the new low energy stack, enhancing the development of Classic Bluetooth enabled devices with new capabilities.

Single-mode chips, which will enable highly integrated and compact devices, will feature a lightweight Link Layer providing ultra-low power idle mode operation, simple device discovery, and reliable point-to-multipoint data transfer with advanced power-save and secure encrypted connections at the lowest possible cost. The Link Layer in these controllers will enable Internet connected sensors to schedule Bluetooth low energy traffic between Bluetooth transmissions.

Expected use cases for Bluetooth low energy technology include sports and fitness, security and proximity and smart energy. Bluetooth low energy technology is designed for devices to have a battery life of up to one year such as those powered by coin-cell batteries. These types of devices include watches that will utilize Bluetooth low energy technology to display Caller ID information and sports sensors that will be utilized to monitor the wearer's heart rate during exercise. The Medical Devices Working Group of the Bluetooth SIG is also creating a medical devices profile and associated protocols to enable Bluetooth applications for this vertical market.

Future
Broadcast channel: Enables Bluetooth information points. This will drive the adoption of Bluetooth into mobile phones, and enable advertising models based on users pulling information from the information points, and not based on the object push model that is used in a limited way today.
Topology management

• Enables the automatic configuration of the piconet topologies especially in scatternet situations that are becoming more common today. This should all be invisible to users of the technology, while also making the technology "just work."
  

QoS improvements

• Enable audio and video data to be transmitted at a higher quality, especially when best effort traffic is being transmitted in the same piconet.
  

UWB for AMP
The high speed (AMP) feature of Bluetooth v3.0 is based on 802.11, but the AMP mechanism was designed to be usable with other radios as well. It was originally intended for UWB, but the WiMedia Alliance, the body responsible for the flavor of UWB intended for Bluetooth, announced in March 2009 that it was disbanding.

On March 16, 2009, the WiMedia Alliance announced it was entering into technology transfer agreements for the WiMedia Ultra-wideband (UWB) specifications. WiMedia has transferred all current and future specifications, including work on future high speed and power optimized implementations, to the Bluetooth Special Interest Group (SIG), Wireless USB Promoter Group and the USB Implementers Forum. After the successful completion of the technology transfer, marketing and related administrative items, the WiMedia Alliance will cease operations.

In October 2009 the Bluetooth Special Interest Group suspended development of UWB as part of the alternative MAC/PHY, Bluetooth v3.0 + HS solution. A small, but significant, number of former WiMedia members had not and would not sign up to the necessary agreements for the IP transfer. The Bluetooth SIG is now in the process of evaluating other options for its longer term roadmap.
( Source : http://en.wikipedia.org/wiki/Bluetooth )

READ MORE - Bluetooth Technology

AVL LT-05/TZ-AVL 05

Automatic Vehicle Location ( AVL ) telecommunication devices. AVL LT-05/TZ-AVL 05 has been tested by Indonesia test house, and has been issued type approval certification in Indonesia at April 22, 2010. The holder of type approval certification AVL LT-05 is Larsen Computing.

Automatic Vehicle Location is a means for automatically determining the geographic location of a vehicle and transmitting the information to a requester.

Contents of packaging :

• GSM Antenna
• GPS Antenna
• Cables
• User manual CD
• below is optional : Configure cable ( Optional I ), Car charge ( Optional I )

Specification Product :

• Dimension : 110mm*66mm*27mm
• Exterior power support : DC 12V-24V
• Inner lithium battery : DC 3.8V - 4.2V
• Exterior GSM Antenna : Receive GSM signal better
• Exterior GPS Antenna : Receive GPS signal better
• Power consumption : Active mode ( avg.)<100ma
• When exterior voltage is 12 V : Seep mode <5ma
• Operating temperature range : -20 C to + 60 C
• Air pressure : 860Kpa - 1060Kpa
• Humidity : up to 70% non condensing
• Position accuracy : 10 - 15 meter
• GSM chip : SIMCOM, Support 3 frequency 800/1800/1900 MHz, ( 4 frequency 850/800/1800/1900MHz is optional )
• GPS Chip : Sirt-star III ( super sensitivity and high accuracy )
• LED : 3 LEDs indicated GSM, GPS signal, and trembling status
  
• Button ( not in the basic version ) : 2 buttons, report location, quick dial ( Optional )
  

Don't forget to used telecommunication device has been type approval certification by DGPT.

READ MORE - AVL LT-05/TZ-AVL 05