2. NB: Wireless Communications Center
In the near feature, no matter where your are,
you could use wireless communications via
NB.
3. Wireless Technology Used in NB
Nowadays, we could only use wireless communications
via NB within limit distance .
WLAN WPAN
- 802.11b - Bluetooth
- 802.11a - Infrared rays
- 802.11g
< 50 m <5m
4. Wireless Personal Area Network
WPAN
Bluetooth
ZigBee
WiMax GSM,
WAP, GRPS,
PHS , UWB
6. Bluetooth (1/2)
Bluetooth is an emerging technology for short-range, low
power wireless applications. The original purpose of
Bluetooth proposed by Ericsson, IBM, Nokia, Intel, and
Toshiba in February 1998. is used to replace cables with RF
transmission and apply to cellular phones, PDAs, digital
Cameras
7. BlueTooth (2/2)
BlueTooth is an open standard version of WPAN (Wireless
Personal Area Network). Identical to IEEE 802.11b, BlueTooth
v1.x adopts 2.4 GHz as its operation frequency band but it utilizes
FHSS (Frequency Hopping Spread Spectrum) as its modulation
scheme. However, compared with IEEE 802.11,
BlueTooth has different market partition The hopping frequency
of BlueTooth is 1600 hops per second, the frequency spectrum is
normally divided into 79 channels with 1 MHz channel spacing
per channel.
8. ZigBee
ZigBee deals with low data rate but very long battery life (months
or even years) and very low complexity.The first edition of the
802.15.4 standard was released in May 2003. In March 2004
ZigBee has two PHY layers that operate in two separate
frequency ranges: 868/915 MHz and 2.4GHz.