Wireless PANs (WPANs) have caused the latest revolution in wireless technology. WPAN’s are short to very short-range (from a couple of centimeters to a couple of meters) wireless networks that can use to exchange information between devices within reach of an individual. WPANs can be used to replace cables between computers and peripherals; share multimedia content amongst devices; build an infrastructure for sensor networking applications, or establish various location-aware services. The best example represents Wireless Personal Area Networks in the industry-standard Bluetooth found in many consumer electronics such as cell phones, PDAs, wireless headsets, wireless mouse, and wireless keyboards.
Why Wireless PANs ?
Personal Area Networks(PAN’s) was first demonstrated by IBM researchers in 1996 that utilized the human body to exchange digital information. Engineers use picoamp currents through the body at very low frequencies of around 1MHz. The low power and frequencies prevented eavesdropping and interference to neighboring PAN’s. In this way, they created a new way to communicate between body-borne appliances by using the human body as a channel. The only Limitation was that some form of human contact between devices is required, which may not always be desirable or possible. To get around this problem of human contact, other alternatives such as IR(Infrared) or Far-field (radio) communications have been considered. Using wireless methods such as IR or radio frequency (RF) for PAN’s is known as WPAN, which are typically smaller, operate on battery power, and either worn on a human body or carried personally. The main design goal of WPANs is to allow either stationary or moving devices that are close to communicating and exchanging information without wires. WPANs should allow devices to create or provide data/voice access points is within a Personal Operating Space(POS) of up to 10 meters in all directions and envelops a stationary or a mobile person.
The WPANs systems are currently expected to provide secure modes of operation, allowing groups of personal devices to interconnect while excluding connectivity to other non-essentials. They should not affect the primary function, the form factor, and power consumption of the devices in which they are embedded. As WPANs primarily use the license-free radio frequencies (e.g., ISM band), they have to coexist with other RF technologies that make of these frequencies. A WPAN is functionally similar to a WLAN while it differs in power consumption, coverage range rate, and cost.
Advantages Of WPANs :
- In PAN no extra space is required.
- It is secure.
- Connect to any device at nay time.
- It is reliable.
- It is easy to use.
- It is portable.
- It is used in TV remotes, AC remotes and so on.
- Data can be synchronized between different devices.
Disadvantages Of WPANs :
- It can operate only in short range of areas
- It is slow data transfer.
- It has limited range.
- Infrared signal travel only in a straight line.
- It use microwave signals in some digital devices which have and effect on the human body like rain and heart problems may occur.
- It is more expensive.