MAY 2018
ID: 21505
During the early days Wi-Fi was being develop, this technology only able cater for low data rate wireless connectivity which allows application such as web browsing and email. Apparently, now with the increase in demands due to the increase in mobility and also ease of use, the popularity of using Wi-Fi to access the internet continues to grow. Owing to that, by 2019 the worldwide data traffic is predicted to increase 10 times more than the number observed in 2014. Therefore, to overcome data traffic issues and to enhance user’s experience, the recent 802.11ax standard have been introduced with an aim to improve system capacity by enhancing reliable throughput in dense environment. This latest technology is said to implement methods that enhances the physical bit rate, reduces the rate of frame error and improves spectral reuse. This is achieved when highly efficient multi-user access is enabled thus increasing the area throughput when interference was reduced. When compared to the traditional 802.11, this earlier technology experience poor transmission efficiency due to the volume enhancement of wireless network. In this context, there will be severe drop in the success rate of channel access due to a large number of wireless networking devices present in a congested network. Therefore, issues involving latency, data losses, error in data as well as energy consumption will occur.

Although 802.11ax standard is still in the early stages of its development, there are a few important features at the PHY and MAC layers have been agreed upon. The first proposed scope of amendment is the improvement in system and user throughputs in dense deployments. This new technology promised to provide 10 times rise in the number of supported user, increase average per user throughput by four times and enhance outdoor and multipath signal robustness. In general, for Wi-Fi deployments, not only involving the increase in number of stations implementing this technology, but also an increase the number of access point also contributes to a denser network. Secondly, is the maintenance and improvement of power efficiency whereby user experience is enhanced in terms of enhancing throughput of end users and also allowing power save modes so that power efficiency can be enhanced. Thirdly, the efficient use of the spectral resources in which this standard proposes methods where usage of spectrum resources is ensured. Lastly, indoor and outdoor operation as well as enabling backward compatibility. In this case, this technology mainly emphasizes on WLAN between 2.4 GHz and 5 GHz, but however will also provide for operation modes between 1 GHz and 6 GHz while for backward compatibility, it said to allow connection with any 802.11 devices.

The goal of the IEEE 802.11ax standard is to increase area of throughput by providing self-configuration and self-adaption facilities. The targeted environments for implementation of this technology covers residential, enterprise, indoor and outdoor BSS hotspots, and vehicular. As for residential areas, due to the installation of huge number of WLAN APs closely to each other, high density of OBBS (Overlapped Basic Service Set is created). Same concept applies to the enterprise which utilizes Wi-Fi as the main source to access internet. For indoor BSS (Basic Service Set) hotspots, APs and non-AP stations are present in this environment are of high density whereby the BSS from each operator is deployed in regular symmetry. Interference may occur due to the overlapping of different cell operators that will cause a drop in performance at any particular area. In cases involving large outdoor BSS hotspots, the main objective of this case is to model outdoor installation which applies the concept similar to cellular mobile networks. This environment consists of large number of non-AP stations at maximum separation between different APs whereby there is potential interference from different non-APs that could cause an effect on user’s experience. Lastly, for vehicular, this recent technology is said to be able to reduce variable interference and to investigate new approaches so that restriction on the infrastructure of vehicle communication can be reduced.

As a conclusion, IEEE 802.11ax is a future high efficiency Wi-Fi standard being designed to increase capacity in dense environments. The scope of the new technology amendment were also being reviewed as well as the intended environment of implementation is explained in this paper.

Z. Zhong, P. Kulkarni, F. Cao, Z. Fan and S. Armour, “Issues and challenges in dense WiFi networks,” 2015 International Wireless Communications and Mobile Computing Conference (IWCMC), Dubrovnik, 2015, pp. 947-951.

G. Naik, S. Bhattarai and J. Park, “Performance Analysis of Uplink Multi-User OFDMA in IEEE 802.11ax,” 2018 IEEE International Conference on Communications (ICC), Kansas City, MO, USA, 2018, pp. 1-6.

M. S. Afaqui, E. Garcia-Villegas and E. Lopez-Aguilera, “IEEE 802.11ax: Challenges and Requirements for Future High Efficiency WiFi,” in IEEE Wireless Communications, vol. 24, no. 3, pp. 130-137, June 2017.