Performance analysis of 802.11ac with frame aggregation using NS3

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

Medium access control protocol design for wireless communications and networks review

Medium access control (MAC) protocol design plays a crucial role to increase the performance of wireless communications and networks. The channel access mechanism is provided by MAC layer to share the medium by multiple stations. Different types of wireless networks have different design requirements such as throughput, delay, power consumption, fairness, reliability, and network density, therefore, MAC protocol for these networks must satisfy their requirements. In this work, we proposed two multiplexing methods for modern wireless networks: Massive multiple-input-multiple-output (MIMO) and power domain non-orthogonal multiple access (PD-NOMA). The first research method namely Massive MIMO uses a massive number of antenna elements to improve both spectral efficiency and energy efficiency. On the other hand, the second research method (PD-NOMA) allows multiple non-orthogonal signals to share the same orthogonal resources by allocating different power level for each station. PD-NOMA has a better spectral efficiency over the orthogonal multiple access methods. A review of previous works regarding the MAC design for different wireless networks is classified based on different categories. The main contribution of this research work is to show the importance of the MAC design with added optimal functionalities to improve the spectral and energy efficiencies of the wireless networks

Characterization and optimization of MIMO systems

In recent years demand for wireless products and networks has experienced substantial growth in the area of digital communications, evolving from novelty into necessity. The deployment has been remarkable in the new generation of IEEE 802.11n-based Wi-Fi technology, which has introduced several enhancements in wireless LAN performance. The most significant innovation has been the introduction of MIMO (multiple-input-multiple-output) interface. MIMO employs an antenna system with multiple transmitters and receivers, improving RF signal quality and increasing efficiency, reliability and throughput. This technology implements advanced signal processing and modulation techniques, added to exploit multiple antennas and wider channels. The potential of MIMO systems bring along several topics. One of these is the choice of design parameters, like, for example, symbol rate, modulation and coding, constellation size and many other. Since the propagation situation can quickly changes, the performance of MIMO systems is determined by its ability to adapt to the changing channel conditions. Thus sophisticated techniques have been proposed to improve the data rate by adapting some of these parameters to the time-varying channel. Another major question is figuring out the ways multiple antennas should be positioned for uncorrelated reception. Due to the fact that antenna elements and propagation channel interact in MIMO systems, the array arrangement strongly influences performance. The configuration has to be chosen carefully with the aim of getting high efficiency in terms of power and a low correlation by exploiting various propagation paths

Evaluations and Enhancements in 802.11n WLANs – Error-Sensitive Adaptive Frame Aggregation

IEEE 802.11n is a developing next-generation standard for wireless local area network (LAN). Seamless multimedia traffic connection will become possible with the 802.11n improvement in the Physical and MAC layer. The new 802.11n frame aggregation technique is particularly important for enhancing MAC layer efficiency under high speed wireless LAN. Although the frame aggregation can increase the efficiency in the MAC layer, it does not provide good performance in high BER channels when using large frame aggregation size. An Optimal Frame Aggregation (OFA) technique for AMSDU frame under different BERs in 802.11n WLANs was proposed. However, the suggested algorithm does not take into account the loss rate and the delay performance requirements for Voice or Video multimedia traffic in various BER channels. The optimal frame size can provide good throughput in the network, but the delay might exceed the Quality of Service (QoS) requirement of Voice traffic or the Frame-Error-Rate (FER) might exceed the maximum loss rate tolerable by the streaming Video traffic. We propose an Error- Sensitive Adaptive Frame Aggregation (ESAFA) scheme which can dynamically set the size of AMSDU frame based on the maximum Frame-Error-Rate (FER) tolerable by a particular multimedia traffic. The simulations show that our adaptive algorithm outperforms the optimal frame algorithm by improving both the delay and the loss rate in the 802.11n WLANs. The measured FER of the Error-Sensitive Adaptive Frame Aggregation scheme can be kept at about the same as the loss rate requirement for Video traffic even under high Bit-Error-Rate (BER) channel. The delay compared to OFA is also decreased by around 50% under different channel conditions. Moreover, the results show that the Error-Sensitive Adaptive Frame Aggregation scheme works particularly well in error-prone wireless networks

Experimental Performance Evaluation and Frame Aggregation Enhancement in IEEE 802.11n WLANs

The IEEE 802.11n standard promises to extend today’s most popular WLAN standard by significantly increasing reach, reliability, and throughput. Ratified on September 2009, this standard defines many new physical and medium access control (MAC) layer enhancements. These enhancements aim to provide a data transmission rate of up to 600 Mbps. Since June 2007, 802.11n products are available on the enterprise market based on the draft 2.0. In this paper we investigate the effect of most of the proposed 802.11n MAC and physical layer features on the adhoc networks performance. We have performed several experiments in real conditions. The experimental results demonstrated the effectiveness of 802.11n enhancement. We have also examined the interoperability and fairness of 802.11n. The frame aggregation mechanism of 802.11n MAC layer can improve the efficiency of channel utilization by reducing the protocol overheads. We focused on the effect of frame aggregation on the support of voice and video applications in wireless networks. We also propose a new frame aggregation scheduler that considers specific QoS requirements for multimedia applications. We dynamically adjust the aggregated frame size based on frame's access category defined in 802.11e standard

QoS based Radio Resource Management Techniques for Next Generation MU-MIMO WLANs: A Survey

IEEE 802.11 based Wireless Local Area Networks (WLANs) have emerged as a popular candidate that offers Internet services for wireless users. The demand of data traffic is increasing every day due to the increase in the use of multimedia applications, such as digital audio, video, and online gaming. With the inclusion of Physical Layer (PHY) technologies, such as the OFDM and MIMO, the current 802.11ac WLANs are claiming Gigabit speeds. Hence, the existing Medium Access Control (MAC) must be in a suitable position to convert the offered PHY data rates for efficient throughput. Further, the integration of cellular networks with WLANs requires unique changes at MAC layer. It is highly required to preserve the Quality of Service (QoS) in these scenarios. Fundamentally, many QoS issues arise from the problem of effective Radio Resource Management (RRM). Although IEEE 802.11 has lifted PHY layer aspects, there is a necessity to investigate MAC layer issues, such as resource utilization, scheduling, admission control and congestion control. In this survey, a literature overview of these techniques, namely the resource allocation and scheduling algorithms are briefly discussed in connection with the QoS at MAC layer. Further, some anticipated enhancements proposed for Multi-User Multiple-Input and Multiple-Output (MU-MIMO) WLANs are discussed

NOMA-based 802.11g/n: PHY analysis and MAC implementation

Industry 4.0 can be considered as the industrial revolution of the current century. Among others, one of its main objectives is the replacement of wired communications by wireless connectivity. The idea is to overcome the main drawbacks of the current wired ecosystem: the lack of mobility, the deployment costs, cable damage and the difficulties with scalability. However, for this purpose, the nature and requirements of the industrial applications must be taken into account, in particular, the proposed communications protocols must support very low loss rates and a strong robustness against failures. This is a very challenging condition due to the nature of the industrial environments (interference with other communication systems, reflections with metallic objects ...). In addition, another characteristic of the industrial applications is the strict requirement related to the latency. On the other hand, industrial applications are not only based on high challenging services, but also exist more flexible requirement applications, such as, web browser, email, video content or complementary information. Those services are considered Best Effort (BE) services. Eventually, in some wireless applications both critical and BE services have to be offered. For those cases, Non-Orthogonal Multiplexing Access (NOMA) technology together with the IEEE 802.11g/n standard is proposed in this document as the physical layer solution. The IEEE 802.11g/n standard has been modified in order to accommodate NOMA schemes, and then, comprehensive simulations are conducted to check and analyze the behavior of the proposed system. It has been determined that through NOMA technology it is possible to obtain better results in certain cases than those achieved in a transmission cases that implements the IEEE 802.11g/n standard in TDM/FDM basis