An extensive review: Internet of things is speeding up the necessity for 5G

The Internet of Things (IoT) is a very large number of objects, with intensive connections and allows these smart objects to be sensed and controlled remotely across efficient network, which is breathing new capability into anything anywhere in the life. This paper presents an overview of about 4G and 5G with their important features and how will drive IoT in future to build smart cities and smart objects. Scientists are concentrates about the advance implementation of these technologies especially the 5G is the term which is not formally used for any current technology and it is still early to provide an exact definition of 5G. We also present an overview of future keys in cellular system to get better IoT such as D2D, M2M, NOMA and Massive MIMO. This work presents the exact steps in 4G and 5G which important towards IoT and the ability to establish the smart cities. Nowadays 4G LTE-A systems are getting maturity and have been installed, the challenge now is how to improve 4G to get a smooth development from 4G to 5G. Among these steps and challenges are considered as the pieces of the 5G using massive MIMO, new access techniques, millimeter wave (mm Wave) and M2M, D2D communication. The future fifth generation (5G) cellular networks have drawn great attention from scientists and companies around the world. 5G cellular networks should accomplish 1,000 times higher mobile data per geographic area. Plus 10-100 times higher number of connecting devices, with low latency and long battery life. KeywordsIoT, smart city, D2D, M2M , and 5G.