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This paper proposes an incremental redundancy hybrid ARQ (IR-HARQ) scheme for the wireless local area network (WLAN) system employing multiband simultaneous transmission. The proposed scheme adopt the rate compatible low-density parity-check (RC-LDPC) codes based on IEEE802.11n LDPC codes and ensure backward compatibility with WLAN devices by using the current WLAN control frame. Additionally, it...
This paper studies appropriate values of EDCA parameters of the author's wireless LAN base station based on Quality of Experience (QoE) for Web Services by experiments with subjects. The base station reduces the traffic of a Web service without degradation of QoE; it utilizes EDCA as QoS control. However, appropriate EDCA parameter value have never been studied. This paper evaluates QoE and measures...
With the rapid growth of smart devices such as smartphones, tablets, and laptops, traffic demands in IEEE 802.11 wireless local area networks (WLANs) has been increased exponentially. To meet the demand, in recent years, numerous access points (APs) have been deployed in many places such as residential areas, shopping malls, airports, office and campus buildings. As the density of 802.11 WLAN increases,...
Due to the limitation of frequency resources, Long Term Evolution(LTE) is usually applied for the train-ground communication applications of Communication(CBTC) service, Wireless Local Network (WLAN) is used for the train ground applications of Passenger Information System (PIS) service and Closed Circuit Television(CCTV) service. Train ground communication systems for PIS and CCTV applications are...
Penetration of multimedia communications with mobile Wi-Fi and tethering requires wireless LANs (WLANs) to guarantee a specific bandwidth in densely deployed WLANs. IEEE802.11e (HCCA) with 802.11aa could use inefficiently radio frequency as well as fail to provide each WLAN with enough CFP period in which sending opportunity of a terminal is guaranteed. To guarantee a specific bandwidth even in densely...
The fifth generation (5G) ultra dense network (UDN) is envisioned as a very dense deployment of low power base stations where heterogeneous radio access technologies are used to satisfy the data rate demand of users employing both licensed and unlicensed spectrum. In UDN scenario, conditions of the channels operating in licensed band may exhibit intermittent characteristics due to the varying level...
The robots having 3G/LTE capability can cooperate with others by using link-aggregation when one needs to send unexpected huge data in high bandwidth to the remote center office. To do so, the robot distributes its data to other robots with IEEE802.11 WLAN. They can move close to the robot to prevent from the situation where the WLAN communication becomes a bottleneck because they are too far to get...
IEEE 802.11 WLANs use carrier sense multiple access with collision avoidance (CSMA/CA) to initiate the Request to Send / Clear to Send (RTS/CTS) handshaking mechanism that solves the hidden node problem. However RTS/CTS also causes the exposed node problem where a node is unnecessarily prevented from accessing the wireless channel even when such access will not disrupt another nodes ongoing transmission...
The availability and reasonable cost of broadband Internet made it an attractive and favourable option to billions of users worldwide. Being a fast service also encourages its users to use real-time applications which is streaming and live data transfer includes VoIP and video streaming. The performance of such applications in Wireless Local Area Network (WLAN) may be highly affected by security protocols...
We propose an optimal Physical Layer Convergence Procedure Protocol Data Unit (PPDU) duration algorithm that divides a long data stream into two portions among consecutive groups based on the average PPDU duration of the Very High Throughput (VHT) group. The proposed solution considers all Wireless Local Area Network (WLAN) parameters and satisfies requirements of the VHT Multi-User Multiple Input...
In dense wireless deployments, such as Enterprise WLANs (EWLANs) and home WLANs, interference may occur because of neighbouring WLANs sharing the same unlicensed spectrum. Mechanisms to centrally manage WLAN deployments cannot effectively mitigate the interference caused by hidden terminals (HTs) in WLANs that belong to different organisations. Furthermore, the impact of interference is amplified...
Recently, wireless local area networks (WLANs) have been densely deployed. In high density WLANs, co-channel interference has become one of the biggest challenges for the network performance. The IEEE 802.11 based WLANs have limited wireless channels, therefore, not all the adjacent APs can work in different non-overlapping channels and co-channel interference will affect the network performance severely...
Throughput starvation, which occurred under well-known exposed/hidden terminal problem in CSMA/CA based channel access mechanisms, will be a critical problem for future wireless LAN systems. This paper describes new schemes that identify starved access points (APs) and user equipments (UEs). One scheme identifies starved APs by observing the delay of beacon signals periodically transmitted by APs...
In 5G heterogeneous evolution, the unlicensed band has captured much attention. Specified by 3GPP Release 13, LTE WLAN aggregation (LWA) is deemed as an effective approach for spectrum integration of 5G heterogeneous networks (HetNet). However, most of previous works about LWA lie in the architecture design, and rarely investigate LWA algorithm analytically. In this paper, we formulate the network...
In recent years, advances in wireless local area network (WLAN) systems have led to large increases in the transmission speed. The IEEE 802.11ac standard allows for very high transmissions by using multi-user multiple input multiple output (MU-MIMO) techniques in the physical (PHY) layer. However, the transmission efficiency is decreased by the channel state information (CSI) estimation algorithm...
Resource allocation and traffic aggregation is becoming a significant part of the network deployment as it is expected that operators will offer advanced services through 5G systems. Scheduling procedures need to be fair but also to handle requirements set for diverse groups of users forming network slices. Heterogeneous networks will need to be controlled locally and the traffic could be split between...
In this work, we introduce a powerful hardware-based rogue access point (PrAP), which can relay traffic between a legitimate AP and a wireless station back and forth, and act as a man-in-the-middle attacker. Our PrAP is built of two dedicated wireless routers interconnected physically, and can relay traffic rapidly between a station and a legitimate AP. Through extensive experiments, we demonstrate...
In wireless LAN, low channel utilization is a serious problem. We have proposed some packet transmission scheduling methods that improve channel utilization by transmitting packets at as high rate as possible through preferential scheduling of packets in proper wireless condition, compared with an existing approach that uses lower transmission rate according to the channel fading around receiver stations...
In this paper we present the first cross-layer analysis of wireless LANs operating under downlink multi-user MIMO (MU-MIMO), considering the fundamental role played by closed-loop (TCP) traffic. In particular, we consider an 802.11ac scenario in which the access point transmits on the downlink via MU-MIMO, whereas stations must employ single-user transmissions on the uplink. With the help of analytical...
Real-time voice and video streaming applications require a certain Quality of Service (QoS) level for providing user satisfaction. As Wireless Local Area Networks (WLAN's) are not designed for such applications, assessing the communication's QoS level is a challenging task. Sudden Onset Disasters (SODs) poses even a greater challenge as the QoS level must be assessed without generating traffic or...
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