I. INTRODUCTION

II. MEASURING GREENNESS: THE METRICS

III. ARCHITECTURE: ENERGY SAVINGS IN BASE STATIONS

IV. NETWORK PLANNING: HETEROGENEOUS NETWORK DEPLOYMENT

V. ENABLING TECHNOLOGIES: COGNITIVE RADIO AND COOPERATIVE RELAYING

VI. DESIGN: ADDRESSING ENERGY EFFICIENCY IN FUTURE GENERATION WIRELESS SYSTEMS

VII. SOME BROADER PERSPECTIVES

VIII. CONCLUSION