Green heterogeneous small-cell networks

The demand for data rates in upcoming wireless standards is increasing exponentially because of data-hungry wireless devices and bandwidth-intensive applications. Moreover, spectral link efficiency is achieving its theoretical limits; therefore, the only solution to enhance the system performance is to improve and densify the base station (BS) deployment in the required areas. This densification, however, presents its own challenges. Adding a BS in the sparsely deployed area does not have much impact on interference and thus cell splitting gains are easy to achieve, whereas adding a BS in the densely deployed urban area generates severe interference per channel and therefore reduces significantly the cell splitting gains. In addition, the site acquisition cost in a capacity-limited dense urban area may also become prohibitively expensive [1].