1) IrDA:

• IrDA is a serial half duplex, line of sight based wireless technology for data communications between devices

• The remote control of TV ,VCD players etc. works on infrared data communication principal.

• Infrared communication technique uses infrared waves of the electromagnetic spectrum for transmitting the data.

• Range from contact to at least 1 meter and can be extended to 2 meters.

• Bi-directional point-to-point communication .

• Data transmission from 9600 b/s with primary speed/cost steps of 115 kb/s an maximum speed up to 16 Mb/s.

• Data packets are protected using a CRC.

2) Wifi

• Wi-Fi is a technology for wireless local area networking with devices based on the IEEE 802.11 standards.

• Wi-Fi is a trademark of the Wi-Fi Alliance, which restricts the use of the term Wi-Fi Certified to products that successfully complete interoperability certification testing.

• Devices that can use Wi-Fi technology include personal computers, video-game consoles, phones and tablets, digital cameras, smart TVs, digital audio players and modern printers.

• Wi-Fi compatible devices can connect to the Internet via a WLAN and a wireless access point. Such an access point (or hotspot) has a range of about 20 meters (66 feet) indoors and a greater range outdoors.

• Hotspot coverage can be as small as a single room with walls that block radio waves, or as large as many square kilometres achieved by using multiple overlapping access points.

• Wi-Fi most commonly uses the 2.4 gigahertz (12 cm) UHF and 5.8 gigahertz (5 cm) SHF ISM radio bands.

• Anyone within range with a wireless modem can attempt to access the network; because of this, Wi-Fi is more vulnerable to attack (called eavesdropping) than wired networks.