IoT wireless technologies. The IoT wireless standards covered are wifi, Z-wave, bluetooth, zigbee, THREAD, RFID, NFC, GPRS, EDGE, UMTS, LTE, ANT+, Cognitive radio, weightless N/W etc. Companies are developing products as per wireless standards outlined here. The idea is to develop IoT product which addresses following key challenges.

• Trade off between power, data rate and coverage range
• Interoperability between wireless standards
• security aspects
• Prevention of interference and failure modes

Wireless	Standard	N/W type	USA Frequency	Max. range	Max. data rate and power	Secu- rity
WiFi	IEEE 802.11a, 11b, 11g, 11n, 11ac, 11ad	WLAN	2.4 , 3.6, 5, 60 GHz	100m,	6-780 Mbps 6.75 Gbps at 60 GHz 1 Watt	WEP, WPA, WPA2
Z-wave	Z-wave	Mesh	908.42 MHz	30m	100Kbps, 1 mW	Triple DES
Bluetooth	Bluetooth, Formerly IEEE 802.15.1	WPAN	2400 to 2483.5 MHz	100m	1 to 3 Mbps, 1 Watt	56/ 128 bit
Bluetooth Smart(BLE)	IoT Inter- connect	WPAN	2400 to 2483.5 MHz	100m	1Mbps, 10-500 mW	128 bit AES
Zigbee	IEEE 802.15.4	Mesh	2400- 2483.5 MHz	10m	250 Kbps, 1mW	128 bit
THREAD	IEEE 802.15.4, 6LoWPAN	Mesh	2400 to 2483.5 MHz	11m	251 Kbps , 2 mWatt	128 bit AES
RFID	Many standards	Point to Point	13.56 MHz	1 m	423 Kbps, about 1mW	Possible
NFC	ISO/IEC 13157	Point to Point	13.56 MHz	0.1m	424 Kbps,1 to 2 mW	Possible
GPRS	3GPP	GERAN	GSM 850 , 1900 MHz	25 Km/ 10 Km	171 Kbps 2W/1W	GEA2/ GEA3 /GEA4
EDGE	3GPP	GERAN	GSM 850/ 1900	26 Km/ 10 Km	384 Kbps, 3W/1W	A5/4, A5/3
HSDPA/ HSUPA	3GPP	UTRAN	850/ 1700/ 1900 MHz	27 Km/ 10 Km	0.73-56 Mbps, 4W/1W	USIM
LTE	3GPP	GERAN/ UTRAN	700-2600 MHz	28 Km/ 10Km	0.1-1Gbps , 5W/1W	SNOW 3G Stream Cipher
ANT+	ANT+ Alliance	WSN	2.4 GHz	100 m	1Mbps, 1mW	AES-128
Cognitive Radio	IEEE 802.22 WG	WRAN	54-862 MHz	100 Km	24 Mbps, 1 W	AES- GCM
Weightless -N/W	Weightless SIG	LPWAN	700/ 900 MHz	5 Km	0.001-10 Mbps, 40mW/4W	128bit

As there are wireless devices designed and developed based on different wireless standards as outlined above, the biggest challenge is interoperability between these devices in the IoT network. The other challenge is interference among these devices due to frequency of operation either in the same band or nearby bands. The radiated power is also the critical factor to be considered for interference related issues