A cell is a area of land covered by a radio tower. A radio tower is vertical mount with installed transceiver's. A transceiver is responsible for sending and receiving radio signals over air. The area covered under a particular cellular tower is known as its cell site. When multiple cell sites interact with each other and with multiple mobile devices a a wireless cellular network is established.
Introduction: LTE is an evolved technology on the wireless evolution path shown below:
GPRS –> EDGE –> UMTS –> evolved 3G capabilities such as HSDPA, HSUPA, HSPA+, IMS –> 4G LTE
During the above evolution path many of the core components involved in all-IP LTE were developed and deployed.