Wireless personal area network WPAN

Wireless personal area network WPAN (Wireless Personal Area Network)

In the individual work places are regarded as personal electronic device connected using wireless technology up ad-hoc network without using an access point AP.
Range of the entire network of around 10 m.
Wireless personal area network WPAN and personal area network PAN (Personal Area Network) is not exactly the same, because the PAN are not always using a wireless connection.

WPAN and WLAN are not the same

WPAN is a wireless personal area network is a person to use the center, which is actually a low-power, small-scale, low-rate and low-cost cable replacement technology. WPAN operate in the ISM band at 2.4 GHz.
The WLAN is at the same time for many users of wireless LAN service, it is a high-power, LAN mid-range, high-speed rate.

WPAN first used in 1994, Ericsson launched the Bluetooth system, the standard is IEEE 802.15.1.
Bluetooth data rate of 720 kb / s, the communication range of about 10 meters.
Bluetooth uses Frequency Hopping Spread Spectrum FHSS TDM manner and without technical components of the base station pico network (piconet).

Piconet literal translation is "piconet", said the coverage of this wireless network is very small.
Each piconet has one master slave (Master) and work up to 7 (Slave).
By sharing the master or slave , may be linked to a plurality of piconet together to form a larger range of diffusion network (scatternet).

Low-speed WPAN network is mainly used for industrial monitoring, and control, office automation field, which is a rate of 2 ~ 250 kb / s.
Low-speed WPAN standard is IEEE 802.15.4. Recently revised standard is IEEE 802.15.4-2006.
The most important is the low-speed WPAN ZigBee .
ZigBee technology is mainly used for a variety of electronic devices (fixed, portable or mobile) wireless communication between its main feature is the short communication distance (10 ~ 80 m), a low transmission data rate, and cost.

ZigBee features

Power consumption is very low. In operation, the signal transmission and reception times is short; while in the non-working, ZigBee node in a dormant state, is power. In the case of some working time and the ratio of the total time of less than 1%, the battery life may be even more than 10 years.
Network capacity. ZigBee network comprises a maximum of 255 nodes, one of which is the master device , with the rest from the apparatus . If by the network coordinator , the entire network can support up to more than 64,000 nodes.

High-speed WPAN for transferring data between the portable multimedia device, supports data rates of 11 ~ 55 Mb / s, the standard 802.15.3.
IEEE 802.15.3a Working Group also proposed physical layer standard of higher data rates hypervelocity a WPAN , UWB uses ultra-wideband technology.
UWB technology works in 3.1 ~ 10.6 GHz microwave band, with a very high channel bandwidth. Bandwidth ultra-wideband signal should be more than 25% of the center frequency of the signal, or an absolute bandwidth of the signal exceeds 500 MHz.
UWB technology uses a high-speed pulse moment, supportable data rate 100 ~ 400 Mb / s can be used for high-speed transmission of multimedia video file or a small range of the image quality DVD.