scholarly journals Performance Analysis of IEEE802.11ac DCF Enhancement for VHT with Frame Aggregation

2016 ◽  
Vol 4 (3) ◽  
pp. 17
Author(s):  
Zineb Machrouh ◽  
Abdellah Najid
Keyword(s):  
Performance Analysis ◽  
Local Area ◽  
Medium Access ◽  
Frame Aggregation ◽  
Channel Bonding ◽  
Data Rates ◽  
5 Ghz ◽  
Access Mechanisms ◽  
Control Layer ◽  
Very High

<strong>IEEE 802.11ac standard has brought several significant improvements compared to its predecessor IEEE 802.11n. It managed to break the Gigabits barrier with a combination of both refining older techniques and presenting new ones. The new enhancements such as channel bonding, beamforming, frames aggregation and finer modulation allow Wireless Local Area Networks (WLAN) the use of Very High Throughput (VHT). The physical layer (PHY) data rates are in the range of Gbps in the 5 GHz band. But the variety of releases and options available for this standard has left many ambiguities regarding its real capabilities. The Medium Access Control layer (MAC) throughput is influenced by several factors, causing the MAC efficiency to decrease. In this paper we present a performance analysis in the VHT with frame aggregation for different access mechanisms, different channels and different modulation schemes.</strong>

scholarly journals Performance analysis of IEEE 802.11ac based WLAN in wireless communication systems

2019 ◽  
Vol 9 (2) ◽  
pp. 1131 ◽  
Author(s):  
A. Z. Yonis
Keyword(s):  
Communication Systems ◽  
Wireless Local Area Network ◽  
Local Area Network ◽  
Multiple Input Multiple Output ◽  
Local Area ◽  
Area Network ◽  
Data Rates ◽  
Input Multiple Output ◽  
Ieee 802.11Ac ◽  
5 Ghz

<p><span lang="EN-US">IEEE 802.11ac based wireless local area network (WLAN) is emerging WiFi standard at 5 GHz, it is new gigabit-per-second standard providing premium services. IEEE 802.11ac accomplishes its crude speed increment by pushing on three distinct measurements firstly is more channel holding, expanded from a maximum of 80 MHz up to 160 MHz modes. Secondly, the denser modulation, now using 256-QAM, it has the ability to increase the data rates up to 7 Gbps using an 8×8 multiple input multiple output (MIMO). Finally, it provides high resolution for both narrow and medium bandwidth channels. This work presents a study to improve the performance of IEEE 802.11ac based WLAN system.</span></p>

scholarly journals IEEE 802.11ah: A Long Range 802.11 WLAN at Sub 1 GHz

2013 ◽  
pp. 83-108
Author(s):  
Weiping Sun ◽  
Munhwan Choi ◽  
Sunghyun Choi
Keyword(s):  
Wireless Lan ◽  
Large Scale ◽  
Transmission Range ◽  
Mac Layer ◽  
Medium Access ◽  
Frequency Spectra ◽  
Ieee 802.11Ah ◽  
Phy Layer ◽  
5 Ghz ◽  
Access Mechanisms

IEEE 802.11ah is an emerging Wireless LAN (WLAN) standard that defines a WLAN system operating at sub 1 GHz license-exempt bands. Thanks to the favorable propagation characteristics of the low frequency spectra, 802.11ah can provide much improved transmission range compared with the conventional 802.11 WLANs operating at 2.4 GHz and 5 GHz bands. 802.11ah can be used for various purposes including large scale sensor networks, extended range hotspot, and outdoor Wi-Fi for cellular traffic offloading, whereas the available bandwidth is relatively narrow. In this paper, we give a technical overview of 802.11ah Physical (PHY) layer and Medium Access Control (MAC) layer. For the 802.11ah PHY, which is designed based on the down-clocked operation of IEEE 802.11ac’s PHY layer, we describe its channelization and transmission modes. Besides, 802.11ah MAC layer has adopted some enhancements to fulfill the expected system requirements. These enhancements include the improvement of power saving features, support of large number of stations, efficient medium access mechanisms and throughput enhancements by greater compactness of various frame formats. Through the numerical analysis, we evaluate the transmission range for indoor and outdoor environments and the theoretical throughput with newly defined channel access mechanisms.

scholarly journals Performance analysis of 802.11ac with frame aggregation using NS3

2020 ◽  
Vol 10 (5) ◽  
pp. 5368
Author(s):  
N. Khalil ◽  
A. Najid
Keyword(s):  
Performance Analysis ◽  
Network Performance ◽  
Gigabit Ethernet ◽  
Frame Aggregation ◽  
Access Points ◽  
Channel Bonding ◽  
Guard Interval ◽  
Coding Schemes ◽  
Research Challenges ◽  
Future Work

802.11ac is an interesting standard of IEEE bringing multiple advantages than its predecessor 802.11n. 802.11ac is faster and more scalable version of 802.11n offering the capabilities of wireless Gigabit Ethernet. 802.11ac will enable access points (AP) to support more STAs with a better experience for clients and more channel bonding increasing from a maximum of 40 MHz with 802.11n up to 80 or 160 MHz with 802.11ac standard. In this paper, we analyze and evaluate the 802.11ac performance using NS3 simulator (v3.26) relying on several features like channel bonding, modulation and coding schemes, guard interval and frame aggregation. Then, we present the effect of the variation of distance between STAs and AP on the network performance in term of throughput. Finally, we capture the most relevant simulations outcomes and we indicate some research challenges for the future work.

scholarly journals Adaptive Two-Level Frame Aggregation for Fairness and Efficiency in IEEE 802.11n Wireless LANs

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Minho Kim ◽  
Eun-Chan Park ◽  
Chong-Ho Choi
Keyword(s):  
Scheduling Algorithm ◽  
Local Area ◽  
Wireless Channel ◽  
Network Throughput ◽  
Channel Access ◽  
Frame Size ◽  
Ieee 802.11N ◽  
Frame Aggregation ◽  
Data Rates ◽  
Adaptation Scheme

This paper deals with the problem of performance degradation in wireless local area networks (WLANs) based on IEEE 802.11n. When a wireless channel is shared by heterogeneous stations that have different data rates and packet sizes, each station occupies a different amount of airtime because the basic channel access mechanism of WLAN was originally designed to provide fair chance of channel access, regardless of packet size and data rate. This leads to the degradation of overall network throughput and airtime fairness among stations, which is known as performance anomaly. To resolve this problem, we firstly formulate an optimization problem for a generalized two-level frame aggregation whose objective is to maximize the achievable throughput under the constraint of airtime fairness. Then, we propose a frame size adaptation scheme that controls the number of packets in an aggregated frame. The proposed scheme is fully compatible with the IEEE 802.11 standard and works in a distributed manner, which neither modifies the channel access mechanism nor resorts to a centralized scheduling algorithm. The extensive simulation results confirm that the proposed scheme tightly regulates the airtime usage of each station to be almost the same and significantly improves the overall network throughput compared to other existing schemes.

scholarly journals Design of Interference-Resilient Medium Access for High Throughput WLANs

2015 ◽  
Vol 2015 ◽  
pp. 1-13
Author(s):  
Luca Reggiani ◽  
Andrea Gola ◽  
Gian Mario Maggio ◽  
Gianluigi Tiberi
Keyword(s):  
Multiple Access ◽  
Network Performance ◽  
High Capacity ◽  
Local Area ◽  
Ultra Wideband ◽  
Indoor Environments ◽  
Performance Study ◽  
Medium Access ◽  
Code Division Multiple ◽  
Control Layer

The proliferation of wireless communications systems poses new challenges in terms of coexistence between heterogeneous devices operating within the same frequency bands. In fact, in case of high-density concentration of wireless devices, like indoor environments, the network performance is typically limited by the mutual interference among the devices themselves, such as for wireless local area networks (WLANs). In this paper, we analyze a protocol strategy for managing multiple access in wireless networks. A network of sensors colocated with the WLAN terminals forms a control layer for managing the medium access and scheduling resources in order to limit collisions and optimize the WLAN data traffic; this control layer is based on a low-power wideband technology characterized by interference robustness, like CDMA (code division multiple access) or UWB (ultra-wideband) for sensors. In this work, we perform an analytical and simulative performance study of the saturated throughput, showing numerical results for the UWB-IR (Impulse Radio) sensors case and highlighting the advantage that can be provided particularly in very high capacity systems, which constitute the necessary evolution of current WLAN versions.

Performance analysis of IEEE 802.11n network under unsaturated conditions

2017 ◽  
Vol 31 (19-21) ◽  
pp. 1740093
Author(s):  
Gaiping Lang ◽  
Lin Ma ◽  
Yubin Xu
Keyword(s):  
Performance Analysis ◽  
Access Control ◽  
Medium Access ◽  
Ieee 802.11N ◽  
Frame Aggregation ◽  
Single Frame ◽  
Access Delay ◽  
Bulk Service ◽  
Multiple Frames ◽  
Aggregation Size

Frame aggregation is the most important medium access control (MAC) enhancement of IEEE 802.11n. In frame aggregation, multiple frames are encapsulated into a single frame. In the analysis of 802.11n performance, the existing researches assumed that each station always had a packet for transmission. But actually, sometimes stations may have no packet to transmit. In this paper, we develop an analytical model for IEEE 802.11n in unsaturated conditions. Therefore, the transmission of the station is assumed to be a bulk service queue system. Bulk size is aggregation size. According to the 802.11n standard, when the number of packets in the buffer is smaller than the aggregation size, we can also transmit all the packets in the buffer using A-MPDU. Therefore, bulk size is variable. The throughput and mean access delay are achieved. Numerical results show that the proposed algorithm can effectively increase the throughput and lower the access delay.

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