While celebrating the 21st year since very first IEEE 802.11 "legacy" 2 Mbit/s wireless local area network standard, latest Wi-Fi newborn is today reaching finish line, topping remarkable speed of 10 Gbit/s. 802.11ax was launched in May 2014 with goal enhancing throughput-per-area high-density scenarios. The draft versions, namely, D1.0 and D2.0, were released at end 2016 2017. Focusing on a more mature version D3.0, this tutorial paper, we help reader to smoothly enter into several major...

The rising tide of the Internet Things has brought to surface numerous low-power, long-range and low-bitrate wireless network technologies. One them, LoRaWAN, is being intensely popularized as a solution for sensor networks, however, its potential limitations are unclear, because there still neither accurate study nor massive LoRaWAN deployment. This paper surveys analyzes operation, focusing on performance evaluation channel access most crucial component machine type communication. We...

LoRaWAN is a promising low power long range wireless communications technology for the Internet of Things. An important feature gateways related to so-called capture effect: under some conditions gateway may correctly receive frame even if it overlaps with other ones. In this paper, we develop pioneering mathematical model network which allows finding capacity and transmission reliability taking into account effect.

In the modern world, a high-speed wireless Internet connection is necessity rather than luxury. To improve efficiency of Wi-Fi networks in dense deployment, novel amendment to standard, namely IEEE 802.11ax introduces Orthogonal frequency-division multiple access (OFDMA). contrast legacy Wi-Fi, where performance station considerable degree depends on rate control, aggregation and other decision-making algorithms implemented at station, 11ax it point that schedules channel time specifies...

While 3GPP has been developing NB-IoT, the market of Low Power Wide Area Networks mastered by cheap and simple Sigfox LoRa/LoRaWAN technologies. Being positioned as having an open standard, LoRaWAN attracted also much interest from research community. Specifically, many papers address efficiency its PHY layer. However MAC is still underinvestigated. Existing studies do not take into account acknowledgement retransmission policy, which may lead to incorrect results. In this paper, we...

IEEE 802.11ah, a new amendment to the Wi-Fi standard, adapts networks emerging Internet of Things (IoT). A key component .11ah is Restricted Access Window (RAW), channel access mechanism, which reduces contention when even thousands IoT devices operate in same area by assigning them different times. This paper shows that existing studies incorrectly understand RAW behavior, oversimplify its modeling and thereby overestimate real system throughput several times, especially for short durations...

To achieve higher throughputs in cellular networks, 3GPP proposes to use unlicensed frequency bands and develops technologies — the latest one is NR-U allowing a base station transmit bands, which are already occupied by Wi-Fi networks. enable fair channel sharing between two technologies, uses sort of CSMA/CA with binary exponential backoff similar Wi-Fi. However, can start data transmission only at strictly periodic time moments. Many papers propose sending reservation signal end procedure...

Extended Reality (XR) - which includes Virtual and Augmented promises to bring the virtual telepresence experience another level. Unfortunately, solutions leveraging these technologies require special high-performance computing platforms that degrade cost-benefit balance. Moving processing cloud solves this problem but imposes strict requirements on data transmission reliability, bandwidth, delays. The satisfaction of becomes an extremely challenging in presence other types delay-sensitive...

IEEE 802.16 protocols for metropolitan broadband wireless access systems have been standardized recently. According to the standard, a subscriber station can deliver bandwidth request messages base by numerous methods. This paper provides both simulation and analytical models investigation of specified random method, which is compared with centralized polling station- grouping mechanisms. Based on assumptions Bernoulli arrival process ideal channel conditions, mean delay transmission...

Distributed media access control (MAC) architecture has many merits to make it a favorable candidate for high-data-rate wireless personal area networks (WPANs) with physical layer (PHY) based on ultrawideband (UWB) technology. This paper focuses the WiMedia MAC, which is first distributed MAC WPANs, approved as standard. In such all devices transmit their beacons provide timing reference and broadcast reservation information, that is, maintain device synchronization. We investigate problems...

Wi-Fi was designed just to replace wired Internet connection, but it has changed the as a whole. Wireless devices generate largest percentage of traffic and market is continuously raising, which brings new challenges connected with more devices, data, higher Quality Experience expectations. Since todays inefficient in terms these challenges, 2013, IEEE LAN/MAN Standard Committee launched task group, aims improve by 2019. In short time, group attracted much attention from leading...

In order to meet the continuously increasing demands for high throughput in wireless networks, IEEE 802 LAN/MAN Standard Committee is developing 802.11ax: a new amendment Wi-Fi standard. This provides various ways improve efficiency of Wi-Fi. The most revolutionary one OFDMA. Apart from obvious advantages, such as decreasing overhead short packet transmission at rates and improving robustness frequency selective interference, being used uplink transmission, OFDMA can increase power spectral...

Wi-Fi was originally designed to provide broadband wireless Internet access for devices which generate rather heavy streams. And succeeded. The coming revolution of the Things with myriads autonomous and machine type communications (MTC) traffic raises a question: can success story be repeated in area MTC? Started 2010, IEEE 802.11 Task Group ah (TGah) has developed draft amendment standard, adapting MTC requirements. performance novel channel enhancements scenarios hardly studied models...

To improve efficiency of wide channel usage in dense scenarios, Wi-Fi community is currently developing a new amendment - 802.11ax which introduces OFDMA Wi-Fi. provide backward compatibility, works on top CSMA/CA, native for Although transmission much more efficient than traditional one, the straightforward functionality leads to low ratio uplink transmissions. This problem can be solved by changing access parameters, done with legacy mechanism. However, heterogeneous network and stations,...

Next generation Wi-Fi networks are expected to support real-time applications that impose strict requirements on the packet transmission delay and loss ratio. Such form an essential target for future standard, namely IEEE 802.11be, development process of which started in 2019. A promising way provide efficient communications 802.11be requires some modification uplink OFDMA feature originally introduced 802.11ax amendment standard. This allows access point reserve channel resources upcoming...

Support of real-time applications that impose strict requirements on packet loss ratio and latency is an essential feature the next generation Wi-Fi networks. Initially introduced in 802.11ax amendment to standard, uplink OFDMA seems be a promising solution for supported low-latency data transmission from numerous stations access point. In this paper, we study how allocate resources network propose algorithm aimed at providing delay less than one millisecond reliability up 99.999\% as...

LPWANs are a promising solution for wireless sensor networks. To compete with such widespread technologies as LoRaWAN and Sigfox, recently new LPWAN technology called NB-Fi has been developed. In short time, many networks have deployed in various countries. Although NB-Fi, designed similar applications, they implement different approaches. However, no detailed comparisons of them present academic literature. This paper aims to fill this gap by analyzing comparing focusing on performance...

Recently appeared the IEEE 802.11ah standard has introduced a new channel access mechanism, so-called Restricted Access Window (RAW). This mechanism allows an point (AP) to reduce contention for in overloaded Wi-Fi networks by limiting number of stations simultaneously accessing channel. The AP divides all associated into groups and allocates each group interval time, which is called RAW slot. paper considers with enabled transmissions crossing slot boundaries, means that station allowed end...

Two amendments to IEEE 802.11 have recently been published: 802.11aa and 802.11ae. Both enhance Quality of Service (QoS) provisioning in Wi-Fi networks by providing support for multicast transmission, enhanced audio video streaming, coping with inter-network interference, improved prioritization management frames. The proposed solutions either extend mechanisms already existing the standard or introduce new ones. Therefore, it is important researchers understand functionalities. To this end...

LoRaWAN infrastructure has become widely deployed to provide wireless communications for various sensor applications. These applications generate different traffic volumes and require quality of service (QoS). The paper presents an accurate mathematical model low-power data transmission in a network, which allows validation key QoS indices, such as network capacity packet loss ratio. Since networks operate the unlicensed spectrum, takes into account attempt failures caused by random noise...