Traffic Offloading in Heterogeneous Cellular Networks

  • Yuan Wu
  • Li Ping Qian
  • Jianwei Huang
  • Xuemin (Sherman) Shen
Part of the SpringerBriefs in Electrical and Computer Engineering book series (BRIEFSELECTRIC)


Media-hungry mobile devices and mobile traffic have been experiencing an exponential growth in the past decade. As reported in Cisco Visual Networking Index (VNI) [1], the global mobile traffic grew from 2.1 exabytes/month at the end of 2014 to 3.7 exabytes/month at the end of 2015, corresponding to 74% growth in 2015, and the growth rate is expected to continue at a compound annual growth rate at 53% until 2020. The huge traffic demand has overloaded cellular radio access networks (RANs), which in comparison experience a much slower capacity increase. It becomes a critical challenge for the cellular operators to accommodate the heavy traffic demand in a timely and cost-efficient manner. Directly upgrading RANs may be undesirable from operators’ perspective for the following two concerns: (i) upgrading RANs requires a huge capital investment, which may not be easily recovered even by accommodating the traffic demand, and (ii) acquiring more licensed spectrum bands for the upgraded RANs is difficult and expensive due to the regulation policy. Fortunately, nowadays cellular networks are structured in a multitier architecture, namely, a large number of heterogeneous small cells (such as picocells, femtocells, and WiFi systems) have densely underlaid conventional macrocells [2]. Hence, traffic offloading through small cells provides an effective and cost-efficient way to accommodate mobile users’ traffic.


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Copyright information

© The Author(s) 2017

Authors and Affiliations

  • Yuan Wu
    • 1
  • Li Ping Qian
    • 1
  • Jianwei Huang
    • 2
  • Xuemin (Sherman) Shen
    • 3
  1. 1.College of Information EngineeringZhejiang University of TechnologyHangzhouChina
  2. 2.Department of Information EngineeringThe Chinese University of Hong KongShatinHong Kong
  3. 3.Department of Electrical and Computer EngineeringUniversity of WaterlooWaterlooCanada

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