Wireless LANs have grown significantly and rapidly in recent years. The expansion brought many benefits to end users, but at the same time it introduced the problem of BSS (Basic Service Set) overlap where the BSS (i.e. WLAN cells) is the fundamental block of IEEE 802.11 WLAN architecture. OBSS occurs because two or more unrelated BSSs are used at the same location, at the same time, and with the same frequency channel. With the expansion of channel bandwidth to 80 MHz (possibly 160 MHz) in upcoming standards, the OBSS problem is likely to become very serious in the future. This article examines how OBSS can be harmful to networks and how it can be avoided through beamforming, distributed coordination between different access points, and energy management. At the end, this text explores the effectiveness of the proposed solutions. INTRODUCTION Wireless Local Area Network (WLAN) is one of the most powerful technologies in the IEEE 802.XX family of standards. WLAN provides free connectivity, mobility and flexibility at a relatively low cost to users. The widespread use of WLAN technology in video streaming and voice applications has spurred high bandwidth capacity for WLANs. Recently, IEEE announced the latest WLAN standard 802.11ac. For 802.11ac to be effective, it requires a wide channel of at least 80 MHz with possibly up to 160 MHz. Increasing bandwidth leads to issues like OBSS. An OBSS problem occurs when two or more BSSs are operating on the same channel and come close to hearing each other. This is an undesirable situation where two or more BSSs compete for channel access and increase contention, which ultimately degrades the performance/efficiency of the WLAN system [1]. The problem was not critical with 802.11a/b/g/n where the channel bandwidth was reasonable. ...... middle of paper ...... on the number of stations it can associate with if the OBSS problem is to be avoided. Ultimately, a few new approaches can potentially improve the performance of OBSS. Works cited [1]. Papadopoulos GZ, “On Improving Capacity Sharing of IEEE 802.11 Overlay Access Points,” September 2011, available: http://georgiospapadopoulos.com/BScThesis.pdf[2]. Smith G., Dillon D., and Janecek J., “Overlapping BSS Proposed Solution – 'OSQAP',” February 2006, available: https://mentor.ieee.org/[3]. Han B., Ji L., Lee S., Miller R., and Bhattacharjee B., “Channel Access Limiting for BSS Overlay Management,” 2009, available: http://www2.research.att.com /~slee/pubs /CAT-OBSS-icc09.pdf[4]. Fang Y., Gu D., McDonald B., and Zhang J., “A Two-Level Carrier Sensing Mechanism for BSS Overlapping Problem in WLAN,” June 2006, available: http://www.merl .com/publications/docs/TR2005-156.pdf