Driven by the growing demand for quality assured 
mobility; new promising technologies have emerged, such as 
4G and 5G networks, in order to meet users' needs.Promising superfast speeds and an end to congestion, 
the technology is expected to revolutionize mobile networks 
and create new economic opportunity: but how exactly will it 
do this and what makes it different to 4G standards?Thereby, we outline the various 
characteristics of 4G systems, i.e. their contributions and their 
behaviors in terms of QoS conservation during the movement 
of subscribers.Keywords--5G, 4G, QoS, Mobile Environments