Hailing Yang¹, Suoping Li^1,2,*, Duo Peng²

CMC-Computers, Materials & Continua, Vol.79, No.3, pp. 5273-5294, 2024, DOI:10.32604/cmc.2024.050869 - 20 June 2024

Abstract To address the problems of network congestion and spectrum resources shortage in multi-user large-scale scenarios, this paper proposes a twice random access OFDMA-NOMA-RA protocol combining the advantages of orthogonal frequency division multiple access (OFDMA) and non-orthogonal multiple access (NOMA). The idea of this protocol is that OFMDA is used to divide the entire frequency field into multiple orthogonal resource units (RUs), and NOMA is used on each RU to enable more users to access the channel and improve spectrum efficiency. Based on the protocol designed in this paper, in the case of imperfect successive interference… More >

Muhammad Awais¹, Shahid Bashir¹, Awais Khan^1,2, Muhammad Asif², Nasim Ullah^3,*, Hend I. Alkhammash⁴

CMC-Computers, Materials & Continua, Vol.75, No.1, pp. 669-681, 2023, DOI:10.32604/cmc.2022.033939 - 06 February 2023

Abstract This paper presents a compact Multiple Input Multiple Output (MIMO) antenna with WLAN band notch for Ultra-Wideband (UWB) applications. The antenna is designed on 0.8 mm thick low-cost FR-4 substrate having a compact size of 22 mm × 30 mm. The proposed antenna comprises of two monopole patches on the top layer of substrate while having a shared ground on its bottom layer. The mutual coupling between adjacent patches has been reduced by using a novel stub with shared ground structure. The stub consists of complementary rectangular slots that disturb the surface current direction and… More >

Abdallah Elhigazi Abdallah¹, Mosab Hamdan², Shukor Abd Razak³, Fuad A. Ghalib³, Muzaffar Hamzah^2,*, Suleman Khan⁴, Siddiq Ahmed Babikir Ali⁵, Mutaz H. H. Khairi¹, Sayeed Salih⁶

CMC-Computers, Materials & Continua, Vol.74, No.3, pp. 5607-5623, 2023, DOI:10.32604/cmc.2023.031047 - 28 December 2022

Abstract IEEE 802.11 Wi-Fi networks are prone to many denial of service (DoS) attacks due to vulnerabilities at the media access control (MAC) layer of the 802.11 protocol. Due to the data transmission nature of the wireless local area network (WLAN) through radio waves, its communication is exposed to the possibility of being attacked by illegitimate users. Moreover, the security design of the wireless structure is vulnerable to versatile attacks. For example, the attacker can imitate genuine features, rendering classification-based methods inaccurate in differentiating between real and false messages. Although many security standards have been proposed… More >

Youngjun Kim¹, Taekook Kim², Hyungoo Choi¹, Jinwoo Park¹, Yeunwoong Kyung^3,*

Intelligent Automation & Soft Computing, Vol.36, No.1, pp. 193-204, 2023, DOI:10.32604/iasc.2023.032784 - 29 September 2022

Abstract Mobility support to change the connection from one access point (AP) to the next (i.e., handover) becomes one of the important issues in IEEE 802.11 wireless local area networks (WLANs). During handover, the channel scanning procedure, which aims to collect neighbor AP (NAP) information on all available channels, accounts for most of the delay time. To reduce the channel scanning procedure, a neighbor beacon frame transmission scheme (N-BTS) was proposed for a seamless handover. N-BTS can provide a seamless handover by removing the channel scanning procedure. However, N-BTS always requires operating overhead even if there More >

Sujit Goswami^1,*, Sujit Kumar Mandal¹, Soumen Banerjee²

CMC-Computers, Materials & Continua, Vol.73, No.1, pp. 397-410, 2022, DOI:10.32604/cmc.2022.025657 - 18 May 2022

Abstract In this paper a novel, compact, microstrip-fed, quad-band monopole antenna is presented for the application of Global System for Mobile communication (GSM 900), Worldwide Interoperability for Microwave Access (WiMAX) and Wireless Local Area Network (WLAN). The proposed antenna comprises of a sickle-shaped structure with four circular arc strips, and a modified rectangular ground plane. The four strips of the antenna are independently responsible for the four different resonant frequencies of the operating bands and can be tuned separately to control the radiation performance. The proposed quad-band antenna is designed to resonate at 940 MHz for GSM More >

Md. Selim Al Mamun^1,2, Fatema Akhter^1,*

CMC-Computers, Materials & Continua, Vol.71, No.2, pp. 3161-3178, 2022, DOI:10.32604/cmc.2022.022214 - 07 December 2021

Abstract Nowadays, wireless local area network (WLAN) has become prevalent Internet access due to its low-cost gadgets, flexible coverage and hassle-free simple wireless installation. WLAN facilitates wireless Internet services to users with mobile devices like smart phones, tablets, and laptops through deployment of multiple access points (APs) in a network field. Every AP operates on a frequency band called channel. Popular wireless standard such as IEEE 802.11n has a limited number of channels where frequency spectrum of adjacent channels overlaps partially with each other. In a crowded environment, users may experience poor Internet services due to… More >

Farhad Bin Ashraf¹, Touhidul Alam^2,*, Md Tarikul Islam³, Mandeep Jit Singh³, Norbahiah Binti Misran³, Mohammad Tariqul Islam³

CMC-Computers, Materials & Continua, Vol.71, No.2, pp. 2271-2284, 2022, DOI:10.32604/cmc.2022.021751 - 07 December 2021

Abstract In this paper, the design and performance analysis of an Inkjet-printed metamaterial loaded monopole antenna is presented for wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) applications. The proposed metamaterial structure consists of two layers, one is rectangular tuning fork-shaped antenna, and another layer is an inkjet-printed metamaterial superstate. The metamaterial layer is designed using four split-ring resonators (SRR) with an H-shaped inner structure to achieve negative-index metamaterial properties. The metamaterial structure is fabricated on low-cost photo paper substrate material using a conductive ink-based inkjet printing technique, which achieved dual negative… More >

M. Vanitha^1,*, J. Kirubakaran², K. Radhika²

Computer Systems Science and Engineering, Vol.40, No.2, pp. 571-579, 2022, DOI:10.32604/csse.2022.017663 - 09 September 2021

Abstract The IEEE 802.11ad innovation has enabled the impact of remote devices in unauthorized 60 GHz unlicensed frequency band at Giga bits per second information transfer rate in speed concentrated 5G applications. We have presented an innovative work that deals with the upgradation of the ability of IEEE 802.11ad wireless LAN to make it suitable for wireless applications. An exact examination on the IEEE 802.11ad analysis has been carried out in this work to achieve the greatest throughput. This has pulled attraction in broad consideration for accomplishing the pinnacle transmission rate of 8 Gbit/s. IEEE 802.11ad… More >

T. Prabhu^1,*, S. Chenthur Pandian²

CMC-Computers, Materials & Continua, Vol.69, No.2, pp. 2549-2562, 2021, DOI:10.32604/cmc.2021.018793 - 21 July 2021

Abstract This paper proposes, demonstrates, and describes a basic T-shaped Multi-Input and Multi-Output (MIMO) antenna with a resonant frequency of 3.1 to 10.6 GHz. Compared with the U-shaped antenna, the mutual coupling is minimized by using a T-shaped patch antenna. The T-shaped patch antenna shapes filter properties are tested to achieve separation over the 3.1 to 10.6 GHz frequency range. The parametric analysis, including width, duration, and spacing, is designed in the MIMO applications for good isolation. On the FR4 substratum, the configuration of MIMO is simulated. The appropriate dielectric material ɛ_r = 4.4 is introduced using More >

Ikhlas Ahmad¹, Haris Dildar¹, Wasi Ur Rehman Khan¹, Sadiq Ullah¹, Shakir Ullah¹, Mahmoud A. Albreem², Mohammed H. Alsharif³, Peerapong Uthansakul^4,*

CMC-Computers, Materials & Continua, Vol.68, No.2, pp. 2563-2578, 2021, DOI:10.32604/cmc.2021.016813 - 13 April 2021

Abstract In this paper, low profile frequency reconfigurable monopole antenna is designed on FR-4 substrate with a compact size of 30 mm³ × 20 mm³ × 1.6 mm³. The antenna is tuned to four different modes through three pin diode switches. In Mode 1 (SW1 to SW3 = OFF), antenna covers a wideband of 3.15–8.51 GHz. For Mode 2 (SW1 = ON, SW2 to SW3 = OFF), the proposed antenna resonates at 3.5 GHz. The antenna shows dual band behavior and covers 2.6 and 6.4 GHz in Mode 3 (SW1 and SW2 = ON, SW3 = OFF). The… More >