Wireless broadband access: WiMAX and beyond - Investigation of bandwidth request mechanisms under point-to-multipoint mode of WiMAX networks

The WiMAX standard specifies a metropolitan area broadband wireless access air interface. In order to support QoS for multimedia applications, various bandwidth request and scheduling mechanisms are suggested in WiMAX, in which a subscriber station can send request messages to a base station, and the base station can grant or reject the request according to the available radio resources. This article first compares two fundamental bandwidth request mechanisms specified in the standard, random access vs. polling under the point-to-multipoint mode, a mandatory transmission mode. Our results demonstrate that random access outperforms polling when the request rate is low. However, its performance degrades significantly when the channel is congested. Adaptive switching between random access and polling according to load can improve system performance. We also investigate the impact of channel noise on the random access request mechanism

Role of Wireless technology in mobile augmented reality system (MARS)

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Efficient Resource Management Mechanism for 802.16 Wireless Networks Based on Weighted Fair Queuing

Wireless Networking continues on its path of being one of the most commonly used means of communication. The evolution of this technology has taken place through the design of various protocols. Some common wireless protocols are the WLAN, 802.16 or WiMAX, and the emerging 802.20, which specializes in high speed vehicular networks, taking the concept from 802.16 to higher levels of performance. As with any large network, congestion becomes an important issue. Congestion gains importance as more hosts join a wireless network. In most cases, congestion is caused by the lack of an efficient mechanism to deal with exponential increases in host devices. This can effectively lead to very huge bottlenecks in the network causing slow sluggish performance, which may eventually reduce the speed of the network. With continuous advancement being the trend in this technology, the proposal of an efficient scheme for wireless resource allocation is an important solution to the problem of congestion. The primary area of focus will be the emerging standard for wireless networks, the 802.16 or “WiMAX”. This project, attempts to propose a mechanism for an effective resource management mechanism between subscriber stations and the corresponding base station

Performance Enhancement of IEEE 802.11AX in Ultra-Dense Wireless Networks

IEEE 802.11ax, which is one emerging WLAN standard, aims at providing highly efficient communication in ultra-dense wireless networks. However, due to a large number of stations (STAs) in dense deployment scenarios and diverse services to be supported, there are many technical challenges to be overcome. Firstly, the potential high packet collision rate significantly degrades the network efficiency of WLAN. In this thesis, we propose an adaptive station (STA) grouping scheme to overcome this challenge in IEEE 802.11ax using Uplink OFDMA Random Access (UORA). In order to achieve optimal utilization efficiency of resource units (RUs), we first analyze the relationship between group size and RU efficiency. Based on this result, an adaptive STA grouping algorithm is proposed to cope with the performance fluctuation of 802.11ax due to remainder stations after grouping. The analysis and simulation results demonstrate that our adaptive grouping algorithm dramatically improves the performance of both the overall system and each STA in the ultra-dense wireless network. Meanwhile, due to the limited RU efficiency of UORA, we adopt the proposed grouping scheme in the Buffer State Report (BSR) based two-stage mechanism (BTM) to enhance the Uplink (UL) Multi-user (MU) access in 802.11ax. Then we propose an adaptive BTM grouping scheme. The analysis results of average RU for each STA, average throughput of the whole system and each STA are derived. The numerical results show that the proposed adaptive grouping scheme provides 2.55, 413.02 and 3712.04 times gains in throughput compared with the UORA grouping, conventional BTM, and conventional UORA, respectively. Furthermore, in order to provide better QoS experience in the ultra-dense network with diverse IoT services, we propose a Hybrid BTM Grouping algorithm to guarantee the QoS requirement from high priority STAs. The concept of ``QoS Utility is introduced to evaluate the satisfaction of transmission. The numerical results demonstrate that the proposed Hybrid BTM grouping scheme has better performance in BSR delivery rate as well as QoS utility than the conventional BTM grouping

Planning and realization of a WiFi 6 network to replace wired connections in an enterprise environment

WiFi (Wireless Fidelity) is a popular wireless LAN technology. It provides broadband wireless connectivity to all the users in the unlicensed 2.4 GHz and 5 GHz frequency bands. Given the fact that the WiFi technology is much easier and cost-efficient to deploy, it is rapidly gaining acceptance as an alternative to a wired local area network. Nowadays the Wireless access to data is a necessity for everyone in the daily life. Considering the last 30 years, the unlimited access to information has transformed entire industries, fueling growth, productivity and profits.The WiFi technology, which is governed by the IEEE 802.11 standards body, has played a key role in this transformation. In fact, thanks to WiFi, users can benefit of low cost access to high data rate wireless connectivity. The first version of the IEEE 802.11 protocol was released in 1997. IEEE 802.11 has been improved with different versions in order to enhance the throughput and support new technologies. WiFi networks are now experiencing the bandwidth-demanding media content as well as multiple WiFi devices for each user. As a consequence of this, WiFi 6, which is based on the IEEE 802.11ax standard, is focused on improving the efficiency of the radio link. However, there is a relatively modest increase in peak data rate too. In this thesis we have planned and realized a WiFi 6 network to replace wired connections in an enterprise environment. To do this the optimal access point placement problem has been taken into account, resulting in an improvement of the coverage. Subsequently, after the configuration from the controller, the performance of the new network has been tested in order to study if WiFi 6 can be used instead of wired connections.WiFi (Wireless Fidelity) is a popular wireless LAN technology. It provides broadband wireless connectivity to all the users in the unlicensed 2.4 GHz and 5 GHz frequency bands. Given the fact that the WiFi technology is much easier and cost-efficient to deploy, it is rapidly gaining acceptance as an alternative to a wired local area network. Nowadays the Wireless access to data is a necessity for everyone in the daily life. Considering the last 30 years, the unlimited access to information has transformed entire industries, fueling growth, productivity and profits.The WiFi technology, which is governed by the IEEE 802.11 standards body, has played a key role in this transformation. In fact, thanks to WiFi, users can benefit of low cost access to high data rate wireless connectivity. The first version of the IEEE 802.11 protocol was released in 1997. IEEE 802.11 has been improved with different versions in order to enhance the throughput and support new technologies. WiFi networks are now experiencing the bandwidth-demanding media content as well as multiple WiFi devices for each user. As a consequence of this, WiFi 6, which is based on the IEEE 802.11ax standard, is focused on improving the efficiency of the radio link. However, there is a relatively modest increase in peak data rate too. In this thesis we have planned and realized a WiFi 6 network to replace wired connections in an enterprise environment. To do this the optimal access point placement problem has been taken into account, resulting in an improvement of the coverage. Subsequently, after the configuration from the controller, the performance of the new network has been tested in order to study if WiFi 6 can be used instead of wired connections

Industrial Wireless Sensor Networks

Wireless sensor networks are penetrating our daily lives, and they are starting to be deployed even in an industrial environment. The research on such industrial wireless sensor networks (IWSNs) considers more stringent requirements of robustness, reliability, and timeliness in each network layer. This Special Issue presents the recent research result on industrial wireless sensor networks. Each paper in this Special Issue has unique contributions in the advancements of industrial wireless sensor network research and we expect each paper to promote the relevant research and the deployment of IWSNs