A person with a Wi-Fi enabled device such as a computer, cell phone or PDA can connect to the Internet when in proximity of an access point. The region covered by one or several access points is called a hotspot. Hotspots can range from a single room to many square  kilometres of  overlapping hotspots. Wi-Fi can also be used to create a mesh network and allows connectivity in peer- to- peer mode. Both architectures are used in community networks.

Discovery:

Despite the similarity between the terms ‘Wi-Fi’ and ‘Hi-Fi’, statements reportedly made by Phil Belanger of the Wi-Fi Alliance contradict the popular conclusion  that ‘Wi-Fi’ stands for ‘Wireless Fidelity. The precursor to Wi-Fi was invented in 1991 by NCR Corporation/AT&T (later Lucent & Agere Systems) in Nieuwegein, the Netherlands.   Vic Hayes, who was the primary inventor of Wi-Fi and has been named the  ‘father of  Wi-Fi,’ was involved in designing standards such as IEEE 802.11b, 802.11a and 802.11g.

Types:

Wi-Fi infrastructure devices typically fall into 3 categores as per it’s Application, with wireless being only one of many features.

1. Wi-Fi At Home
Home Wi-Fi clients come in many shapes and sizes, from stationary PCs to digital cameras. The trend today and into the future will be to enable wireless into every devices where mobility is prudent.

Wi-Fi devices are often used in home or consumer-type environments in the following manner:

• Termination of a broad band connection into a single router which services both wired and wireless clients, where cable connection can not be hooked up.
• Ad-hoc mode for client to client connections ,
• Built into non-computer devices to enable simple wireless connectivity to other devices or the Internet.

2. Wi-Fi in Business
In Business and Industry  current Technology of  Wi-Fi  is  moving toward ‘thin’ Access Points, with all of the intelligence housed in a centralized network appliance; relegating individual Access Points to be simply ‘dumb’ radios   utilizing true mesh topologies.

3.Wi-Fi in gaming
Some gaming consoles and hand helds make use of Wi-Fi technology to enhance the gaming experience   in local multiplayer as well as connecting to wireless networks for online game play or with separate adapter.

Technical information

Wi-Fi: How it Works

A typical Wi-Fi setup contains one or more Access Points (APs) and one or more clients. An AP broadcasts its SSID (Service Set Identifier, “Network name”) via packets that are called beacons, which are usually broadcast every 100 ms. The beacons are transmitted at 1 Mbit/s, and are of relatively might use signal strength to decide which of the two APs to make a connection to. The Wi-Fi standard leaves connection criteria and roaming totally open to the client. Since Wi-Fi transmits in the air, it has the same properties as a non-switched wired Ethernet network, and therefore collisions can occur  , which can not be   detected, and instead uses a packet exchange (RTS/CTS used for Collision Avoidance or CA) to try to avoid collisions.

Channels:
Wi-Fi uses the spectrum near 2.4 GHz, which is standardized, although the exact frequency allocations vary slightly in different parts of the world, as does maximum permitted power, except for 802.11a,which operates at 5 GHz.. However, channel numbers are standardized by frequency throughout the world, so authorized frequencies can be identified by channel numbers. The maximum number of available channels for Wi-Fi enabled devices are:

• 13 for Europe
• 11 for North America. Only channels 1, 6, and 11 are recommended for 802.11b/g to minimize interference from adjacent channels.
• 14 for Japan.

Standard Devices

A wireless access point connects a group of wireless devices to an adjacent wired LAN. An access point is similar to an ethernet  hub, relaying data between connected wireless devices in addition to a (usually) single connected wired device, most often an ethernet hub or switch, allowing wireless devices to communicate with other wired devices.

The post Wi-Fi Technology first appeared on Student Projects.

The VMSS (Vehicle Monitoring and Security System) is a GPS based vehicle tracking system that is used for security applications as well. The project uses two main underlying concepts. These are GPS (Global Positioning System) and GSM (Global System for Mobile Communication). The main application of this system in this context is tracking the vehicle to which the GPS is connected, giving the information about its position whenever required and for the security of each person travelling by the vehicle. This is done with the help of the GPS satellite and the GPS module attached to the vehicle which needs to be tracked. The GPS antenna present in the GPS module receives the information from the GPS satellite in NMEA (National Marine Electronics Association) format and thus it reveals the position information. This information got from the GPS antenna has to be sent to the Base station wherein it is decoded. For this we use GSM module which has an antenna too. Thus we have at the Base station; the complete data about the vehicle.

Along with tracking the vehicle, the system is used for security applications as well. Each passenger/employee will have an ID of their own and will be using a remote containing key for Entry, Exit and Panic. The Panic button is used by the driver or the passenger so as to alert the concerned of emergency conditions. On pressing this button, an alarm will be activated which will help the passenger/employee in emergencies and keep them secure throughout the journey. The vehicle can also be immobilized remotely.

INTRODUCTION:

Of all the applications of GPS, Vehicle tracking and navigational systems have brought this technology to the day-to-day life of the common man. Today GPS fitted cars, ambulances, fleets and police vehicles are common sights on the roads of developed countries. Known by many names such as Automatic Vehicle Locating System (AVLS), Vehicle Tracking and Information System (VTIS), Mobile Asset Management System (MAMS), these systems offer an effective tool for improving the operational efficiency and utilization of the vehicles.

GPS is used in the vehicles for both tracking and navigation. Tracking systems enable a base station to keep track of the vehicles without the intervention of the driver whereas navigation system helps the driver to reach the destination. Whether navigation system or tracking system, the architecture is more or less similar. The navigation system will have convenient, usually a graphic display for the driver which is not needed for the tracking system. Vehicle tracking systems combine a number of well-developed technologies.

To design the VMSS system, we combined the GPS’s ability to pin-point location along with the ability of the Global System for Mobile Communications (GSM) to communicate with a control center in a wireless fashion. The system includes GPS-GSM modules and a base station called the control center.

Let us briefly explain how VMSS works. In order to monitor the vehicle, it is equipped with a GPS-GSM VMSS system. It receives GPS signals from satellites, computes the location information, and then sends it to the control center. With the vehicle location information, the control center displays all of the vehicle positions on an electronic map in order to easily monitor and control their routes. Besides tracking control, the control center can also maintain wireless communication with the GPS units to provide other services such as alarms, status control, and system updates.

The design takes into consideration important factors regarding both position and data communication. Thus, the project integrates location determination (GPS) and cellular (GSM) – two distinct and powerful technologies in a single system.

VMSS is based on a PIC microcontroller-based system equipped with a GPS receiver and a GSM Module operating in the 900 MHz band. We housed the parts in one small plastic unit, which was then mounted on the vehicle and connected to GPS and GSM antennas. The position, identity, heading, and speed are transmitted either automatically at user-defined time intervals or when a certain event occurs with an assigned message (e.g.; accident, alert, or leaving/entering an admissible geographical area).

The GPS Module outputs the vehicle location information such as longitude, latitude, direction, and Greenwich Time every five minutes. The GSM wireless communications function is based on a GSM network established in a valid region and with a valid service provider. Via the SMS provided by the GSM network, the location information and the status of the GPS-GSM VMSS are sent to the control center. Meanwhile, the VMSS receives the control information from the control center via the same SMS. Next, the GPS-GSM VMSS sends the information stored in the microcontroller via an RS-232 interface.

There are two ways to use the VMSS’ alarm function, which can be signified by either a buzzer or presented on LCD. The first way is to receive the command from the control center; second way is to manually send the alarm information to the control center with the push of a button.

The base station consists of landline modem(s) and GIS workstation. The information about the vehicle is received at a base station and is then displayed on a PC based map. Vehicle information can be viewed on electronic maps via the Internet or specialized software. Geographic Information Systems (GIS) provides a current, spatial, visual representation of transit operations. It is a special type of computerized database management system in which geographic databases are related to one via a common set of location coordinates.

STAGES OF VMSS

STAGE 1:

1. Driver starts his trip from the transport office.
2. VMSS transmits the Driver I.D and the Vehicle I.D along with the position of the vehicle to the base station.

STAGE 2:

1. Taxi picks up the employee/passenger from their residence.
2. VMSS transmits the Passenger I.D and the Vehicle I.D along with the position of the vehicle to the base station. Therefore base station will be able to keep a track of the vehicle and thus the employee/passenger.

STAGE 3:

1. Taxi drops the employee/passenger to the workplace.
2. VMSS transmits the Passenger I.D and the Vehicle I.D along with the position of the vehicle to the base station.

STAGE 4:

1. Taxi picks the employee/passenger from the workplace.
2. VMSS transmits the Passenger I.D and the Vehicle I.D along with the position of the vehicle to the base station. Therefore this enables the base station to estimate the time if required and also keep a track of the vehicle, passenger and the driver.

STAGE 5:

1. Taxi drops the employee/passenger to their residence.
2. VMSS transmits the Passenger I.D and the vehicle I.D along with the position of the vehicle to the base station and makes sure that the job is 100% complete.
   

   The post Vehicle Monitoring and Security System first appeared on Student Projects.

   ]]> https://studentprojects.in/electronics/microcontrollers/vehicle-monitoring-and-security-system/feed/ 149