A MAC Performance of Mobile Ad hoc 802 11ac LAN Over Correlated Fading Channel

Abstract

Abstract-FER (Frame ErrorRate Ⅰ. INTRODUCTIONOver the past few years, wireless LAN have been deployed rapidly across enterprises, homes, public sectors and service providers due to mobility, flexibility, interoperability and cost-effective deployment. It is expected that wireless LAN have emerged as a promising network for future IP applications. When wireless channel experiences fading, bit errors occur and its performance decreases largely. Also, with the limited frequency resources, designing an effective MAC protocol is a hot challenge. The legacy IEEE 802.11b and 802.11g/a specification provide up to 11 and 54 Mbps data rates, respectively. They employs a CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance) protocol with binary exponential back-off as the MAC protocol. IEEE 802.11n allows coexistence with IEEE 802.11b/g/a legacy devices [1]. It delivers a theoretical maximum throughput of 600 Mbps at physical layer and has maximum data throughput of at least 100 Mbps as measured at the MAC SAP(Service Access Point). IEEE 802.11ac is an amendment to IEEE 802.11 for very high throughput (VHT) operation in frequency bands below 6 GHz, excluding 2.4 GHz (i.e., unlicensed bands at 5 GHz band) [2]. The previous researches have been executed on the DCF performance over wireless LAN [3]. ______________________________________________ Ha Cheol Lee Yuhan University KoreaIn case of IEEE 802.11n, the throughput performance at the MAC layer can be improved by aggregating several frames before transmission [4]. Frame aggregation not only reduces the transmission time for preamble and frame headers, but also reduces the waiting time during CSMA/CA random backoff period for successive frame transmissions. Under error-prone channels, corrupting a large aggregated frame may waste a long period of channel time and lead to a lower MAC efficiency. The previous paper analyzed the IEEE 802.11b/g/a/n MAC performance for wireless LAN with error-free and errorprone channel [3,[5][6][7]. Papers related to IEEE 802.11ac also analyzed MAC throughput, but did not consider mobile ad-hoc and error-prone environment that is applied to most wireless LAN [8][9][10][11]. So, this paper extends the previous IEEE 802.11ac performance researches and analyzes the IEEE 802.11ac MAC performance for mobile ad-hoc LAN under the errorprone channel environment. In Section 2, IEEE 802.11ac PHY and MAC layer are reviewed. In Section 3 and Section 4, saturation throughput with bit errors appearing in the wireless channel are numerically analyzed and evaluated. In Section 5, it is concluded with remarks.