IEEE 802.11n MAC frame aggregation mechanisms for next-generation high-throughput WLANs [Medium access control protocols for wireless LANs]

IEEE 802.11n is an ongoing next-generation wireless LAN standard that supports a very highspeed connection with more than 100 Mb/s data throughput measured at the medium access control layer. This article investigates the key MAC enhancements that help 802.11n achieve high throughput and high efficiency. A detailed description is given for various frame aggregation mechanisms proposed in the latest 802.11n draft standard. Our simulation results confirm that A-MSDU, A-MPDU, and a combination of these methods improve extensively the channel efficiency and data throughput. We analyze the performance of each frame aggregation scheme in distinct scenarios, and we conclude that overall, the two-level aggregation is the most efficacious

Performance evaluation of the IEEE 802.11n random topology WLAN with QoS application

The IEEE 802.11n supports high data rate transmissions due its physical layer Multiple Input ‎Multiple Output (MIMO) advanced antenna system and MAC layer enhancement features (frame ‎aggregation and block acknowledgement). As a result this standard is very suitable for multimedia ‎services through its Enhanced Distributed Channel Access (EDCA). This paper focuses on ‎evaluating the Quality of Service (QoS) application on the performance of the IEEE 802.11n ‎random topology WLAN. Three different number of nodes (3, 9 and 18) random topology with one ‎access point are modeled and simulated by using the Riverbed OPNET 17.5 Modular to ‎investigate the Wireless Local Area Network (WLAN) performance for different spatial streams. ‎The result clarified the impact of QoS application and showed that its effect is best at the 18 node ‎number topology. For a 4x4 MIMO, when QoS is applied and with respect to the no QoS ‎application case, simulation results show a maximum improvement of 86.4%, 33.9%, 52.2% and ‎‎68.9% for throughput, delay, data drop and retransmission attempts, respectively.

Análisis comparativo de métricas de QoS de Redes Wi-Fi 802.11e con capa física 802.11n y 802.11ac

Las Redes Inalámbricas basadas en IEEE 802.11 se han vuelto las redes más populares en el acceso a los servicios WLAN corporativos y de banda ancha móvil/wireless de Internet. Para satisfacer los requerimientos de QoS (Quality of Service - Calidad de Servicio) se introdujo, a nivel de Capa 2, la tecnología IEEE EDCA (Enhanced Distributed Channel Access) 802.11e. Mientras que para satisfacer mayores velocidades de transferencias, a nivel de Capa 1, se han sucedido diversas mejoras introducidas con IEEE 802.11n y IEEE 802.11ac. Estas últimas tecnologías establecen características PHY y MAC obligatorias y opcionales. En este proyecto de investigación se propone un análisis comparativo de las métricas de QoS de Wi-Fi entre 802.11a, 802.11n y 802.11ac, evaluando el nivel de mejoras alcanzadas con las técnicas de agregación MAC Service Data Unit (A-MSDU) y MAC Protocol Data Unit (A-MPDU), y con diferente número de streams espaciales y de ancho de banda de canal. La experimentación se realizará mediante simulación usando una variante del modelo de estación (STA) EDCA 802.11e construido con Redes de Petri (Universidad de Porto) combinado con el simulador Möbius (Universidad de Illinois).Eje: Arquitecturas, Redes y Sistemas OperativosRed de Universidades con Carreras en Informática (RedUNCI

Análisis comparativo de métricas de QoS de Redes Wi-Fi 802.11e con capa física 802.11n y 802.11ac

Las Redes Inalámbricas basadas en IEEE 802.11 se han vuelto las redes más populares en el acceso a los servicios WLAN corporativos y de banda ancha móvil/wireless de Internet. Para satisfacer los requerimientos de QoS (Quality of Service - Calidad de Servicio) se introdujo, a nivel de Capa 2, la tecnología IEEE EDCA (Enhanced Distributed Channel Access) 802.11e. Mientras que para satisfacer mayores velocidades de transferencias, a nivel de Capa 1, se han sucedido diversas mejoras introducidas con IEEE 802.11n y IEEE 802.11ac. Estas últimas tecnologías establecen características PHY y MAC obligatorias y opcionales. En este proyecto de investigación se propone un análisis comparativo de las métricas de QoS de Wi-Fi entre 802.11a, 802.11n y 802.11ac, evaluando el nivel de mejoras alcanzadas con las técnicas de agregación MAC Service Data Unit (A-MSDU) y MAC Protocol Data Unit (A-MPDU), y con diferente número de streams espaciales y de ancho de banda de canal. La experimentación se realizará mediante simulación usando una variante del modelo de estación (STA) EDCA 802.11e construido con Redes de Petri (Universidad de Porto) combinado con el simulador Möbius (Universidad de Illinois).Eje: Arquitecturas, Redes y Sistemas OperativosRed de Universidades con Carreras en Informática (RedUNCI

Análisis comparativo de métricas de QoS de Redes Wi-Fi 802.11e con capa física 802.11n y 802.11ac

Las Redes Inalámbricas basadas en IEEE 802.11 se han vuelto las redes más populares en el acceso a los servicios WLAN corporativos y de banda ancha móvil/wireless de Internet. Para satisfacer los requerimientos de QoS (Quality of Service - Calidad de Servicio) se introdujo, a nivel de Capa 2, la tecnología IEEE EDCA (Enhanced Distributed Channel Access) 802.11e. Mientras que para satisfacer mayores velocidades de transferencias, a nivel de Capa 1, se han sucedido diversas mejoras introducidas con IEEE 802.11n y IEEE 802.11ac. Estas últimas tecnologías establecen características PHY y MAC obligatorias y opcionales. En este proyecto de investigación se propone un análisis comparativo de las métricas de QoS de Wi-Fi entre 802.11a, 802.11n y 802.11ac, evaluando el nivel de mejoras alcanzadas con las técnicas de agregación MAC Service Data Unit (A-MSDU) y MAC Protocol Data Unit (A-MPDU), y con diferente número de streams espaciales y de ancho de banda de canal. La experimentación se realizará mediante simulación usando una variante del modelo de estación (STA) EDCA 802.11e construido con Redes de Petri (Universidad de Porto) combinado con el simulador Möbius (Universidad de Illinois).Eje: Arquitecturas, Redes y Sistemas OperativosRed de Universidades con Carreras en Informática (RedUNCI

milliProxy: a TCP Proxy Architecture for 5G mmWave Cellular Systems

TCP is the most widely used transport protocol in the internet. However, it offers suboptimal performance when operating over high bandwidth mmWave links. The main issues introduced by communications at such high frequencies are (i) the sensitivity to blockage and (ii) the high bandwidth fluctuations due to Line of Sight (LOS) to Non Line of Sight (NLOS) transitions and vice versa. In particular, TCP has an abstract view of the end-to-end connection, which does not properly capture the dynamics of the wireless mmWave link. The consequence is a suboptimal utilization of the available resources. In this paper we propose a TCP proxy architecture that improves the performance of TCP flows without any modification at the remote sender side. The proxy is installed in the Radio Access Network, and exploits information available at the gNB in order to maximize throughput and minimize latency.Comment: 7 pages, 6 figures, 2 tables, presented at the 2017 51st Asilomar Conference on Signals, Systems and Computers, Pacific Grove, CA, 201

Improving Performance of QUIC in WiFi

QUIC is a new transport protocol under standardization since 2016. Initially developed by Google as an experiment, the protocol is already deployed in large-scale, thanks to its support in Chromium and Google's servers. In this paper we experimentally analyze the performance of QUIC in WiFi networks. We perform experiments using both a controlled WiFi testbed and a production WiFi mesh network. In particular, we study how QUIC interplays with MAC layer features such as IEEE 802.11 frame aggregation. We show that the current implementation of QUIC in Chromium achieves sub-optimal throughput in wireless networks. Indeed, burstiness in modern WiFi standards may improve network performance, and we show that a Bursty QUIC (BQUIC), i.e., a customized version of QUIC that is targeted to increase its burstiness, can achieve better performance in WiFi. BQUIC outperforms the current version of QUIC in WiFi, with throughput gains ranging between 20% to 30%

Improving VHT MU-MIMO communications by concatenating long data streams in consecutive groups

communication mode that allows an Access Point (AP) to simultaneously transmit multiple data streams as Aggregated Multi-Protocol Data Units (A-MPDUs) to a group of multiple stations (STAs) over the same channel. This mode combines communication technologies that enable the 802.11ac protocol to use spectrum more efficiently compared to the previous standards. However, VHT MU-MIMO wastes an unused part of the Physical Protocol Data Unit (PPDU) interval when short and long data streams are grouped together. In this paper, we propose a solution that improves VHT MU-MIMO communications by reducing wasted portion of the PPDU duration of short data streams by concatenating longer data streams in consecutive groups. Simulations of the VHT MU-MIMO communication process with and without the proposed approach indicate smaller wasted part and shorter transmission time of randomly generated STAs data streams

IEEE 802.11n aggregation performance study for the multicast

Abstract- One of the major features proposed in the IEEE 802.11n amendment is the use of frame aggregation. Thus, two types of frame aggregations are defined: MAC Service Data Unit Aggregation (A-MSDU) and MAC Protocol Data Unit Aggregation (A-MPDU). As frame aggregation is mainly defined to increase the efficiency of the MAC layer, this feature is very needed to support multimedia traffic such as High Definition TV (HDTV). The multicast transport is another way to increase the MAC layer efficiency by transmitting the same information only once to many receivers. However, the 802.11 standard does not define a reliable multicast and consequently the 802.11n is unable to provide a reliable transport for multicast streams. The 802.11aa remains the only draft to handle the unreliability issue of the multicast, but the proposed solution is defined only for the legacy 802.11 standard and does not consider the aggregation feature of the 802.11n. In this paper we design a new extension for the 802.11aa in order to take a full advantage of the 802.11n capabilities and we provide a new analytical model to evaluate the performance of the MAC layer. We particularly study the impact of the frame aggregation type on the MAC throughput for the multicast transport. Our results show that in an ideal channel (no losses), A-MSDU slightly outperforms A-MPDU when using the data rate of 6.5Mbps and both schemes have the same performance with rates of 130 and 300 Mbps. However the use of A-MPDU aggregation becomes more efficient in a noisy channel. I