i) IRDA-
1) InfraRed (IrDA) is a serial half duplex, line of sight based wireless technology for data communications between devices.
2) The remote control of TV, VCD players etc. works on the infrared data communication principle.
3) Infrared communication technique uses infrared waves of the electromagnetic spectrum for transmitting the data.
4) IrDA supports point-to-point and point-to-multipoint communication provided that all the devices involved in the communication are within the line of sight.
5)The typical communication range for IrDA lies in the range 10 cm to 1 m. The range can be increased by increasing the transmitting power of the IR device.
6) IR supports data rates ranging from 9600 bits/second to 16 Mbps.
7)IR is classified into Serial IR (SIR), Medium IR (MIR), Fast IR (FIR) depending on the speed of data transmission.

ii) Bluetooth features :-
1) IEEE Standard 802.15.1
2) Frequency (GHz) 2.4
3) Maximum raw bit rate (Mbps) 1-3
4) Typical data throughput (Mbps) 0.7-2.1
5) Maximum (Outdoor) Range (Meters) 10 (class 2), 100 (class 1)

iii) Zigbee features :- 1) IEEE Standard 802.15.4
2) Frequency (GHz) 0.868, 0.915, 2.4
3) Maximum raw bit rate (Mbps) 0.250
4) Typical data throughput (Mbps) 0.2
5) Maximum (Outdoor) Range (Meters) 10-100
6) Relative Power Consumption Very low

iv) IEEE 802.11
1) Wi-Fi follows the IEEE 802.11 standard.
2) Wi-Fi enabled devices contain wireless adaptor for transmitting and receiving data in the form of radio signals through an antenna. The hardware part of it is known as Wi-Fi Radio.
3) Wi-Fi operates on 2.4 GHz or 5 GHz of radio spectrum and they can exist with other ISM band devices in a Wi-Fi network.
4) For communication with devices over a Wi-Fi network, the device, when its Wi-Fi radio is turned ON, searches the available Wi-Fi network in its vicinity and lists out the Service Set Identifier (SSID) of the available networks.
5) If the network is security enabled, a password may be required to connect to a particular SSID.
6) Wi-Fi employs different security mechanisms like Wired Equivalent Privacy (WEP), Wireless Protected Access (WPA) etc. for securing the data communication.
7) Wi-Fi supports data rates ranging from 1 Mbps to 150 Mbps and access/modulation method.