7.1 Enabling Technologies for Multi-Radio Heterogeneous Networks
7.1.1 Understanding Challenges in Mobile Wireless Networking
The rapid expansion of wireless communications over recent decades has introduced fundamental changes to “anytime, anywhere” mobile Internet access, and has also posed new challenges for the research community. In recent years, the wireless standards community has completed the fourth generation (4G) of broadband communication technology , which offers numerous advances in wireless system design, resulting in significant improvements in spectral and energy efficiencies as well as user quality of service (QoS). However, with the predicted explosion in both types and numbers of wireless devices it is commonly believed that despite novel 4G technologies, mobile broadband networks will face a capacity crunch in the near future.
Indeed, current multi-tier cellular technologies are already seeing high diversity in data rates, suffer from excessive time delays, or sometimes even service outages due to poor coverage and harsh interference conditions. Cellular coverage also remains unsatisfactory in indoor environments despite aggressive ...