Commercial wireless communication systems and technologies have evolved over the years from narrow band analog cellular phone system of the 70s to todays connected devices for highly integrated Internet of Everything (IOE). The primary purpose of the first generation (1G) cell phones was voice communication over the air. The analog 1G system transitioned to digital 2G wireless system to enable data and voice communication. It further expanded to 3G and 4G system as the demand for more data and video streaming increased. Developmental work is now underway to launch 5G system to provide high speed, high bandwidth transmission of data and video. In addition to cellular system evolution, other wireless systems like Wireless LAN, Bluetooth, LPWA etc. were also deployed for short range communication.

Cellular systems based on 3G and 4G standards adopted Long Term Evolution (LTE) protocol that employs many frequency bands and varying bandwidths, whereas the wireless LAN type shorter range communication system is governed by IEEE 802.11 standards. Regulatory bodies around the world collaborated in assigning spectrum for wireless transmission. In order to achieve the vision of 5G and IOE, highly efficient wireless system that connects devices to devices are needed.