The Use of Orthogonal Frequency Code Division (OFCD) Multiplexing in Wireless Mesh Network (WMN)

2010 ◽  
pp. 565-581
Author(s):  
Syed S. Rizvi ◽  
Khaled M. Elleithy ◽  
Aasia Riasat
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Multiple Access ◽  
Mesh Networks ◽  
Network Capacity ◽  
Network Throughput ◽  
High Data ◽  
Wireless Mesh ◽  
Frequency Code ◽  
Access Scheme ◽  
Potential Use

In the present scenario, improvement in the data rate, network capacity, scalability, and the network throughput are some of the most serious issues in wireless mesh networks (WMN). Specifically, a major obstacle that hinders the widespread adoption of WMN is the severe limits on throughput and the network capacity. This chapter presents a discussion on the potential use of a combined orthogonal-frequency code-division (OFCD) multiple access scheme in a WMN. The OFCD is the combination of orthogonal frequency division multiplexing (OFDM) and the code division multiple access (CDMA). Since ODFM is one of the popular multi-access schemes that provide high data rates, combining the OFDM with the CDMA may yield a significant improvement in a WMN in terms of a comparatively high network throughput with the least error ration. However, these benefits demand for more sophisticated design of transmitter and receiver for WMN that can use OFCD as an underlying multiple access scheme. In order to demonstrate the potential use of OFCD scheme with the WMN, this chapter presents a new transmitter and receiver model along with a comprehensive discussion on the performance of WMN under the new OFCD multiple access scheme. The purpose of this analysis and experimental verification is to observe the performance of new transceiver with the OFCD scheme in WMN with respect to the overall network throughput, bit error rate (BER) performance, and network capacity. Moreover, in this chapter, the authors provide an analysis and comparison of different multiple access schemes such as FDMA, TDMA, CDMA, OFDM, and the new OFCD.

scholarly journals On the Achievable Max-Min User Rates in Multi-Carrier Centralized NOMA-VLC Networks

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3705
Author(s):  
Omar Maraqa ◽  
Umair F. Siddiqi ◽  
Saad Al-Ahmadi ◽  
Sadiq M. Sait
Keyword(s):  
Power Allocation ◽  
Orthogonal Frequency Division Multiplexing ◽  
Multiple Access ◽  
Low Complexity ◽  
Subcarrier Allocation ◽  
Visible Light Communications ◽  
User Pairing ◽  
High Data ◽  
Access Scheme ◽  
Optimal Resource

Visible light communications (VLC) is gaining interest as one of the enablers of short-distance, high-data-rate applications, in future beyond 5G networks. Moreover, non-orthogonal multiple-access (NOMA)-enabled schemes have recently emerged as a promising multiple-access scheme for these networks that would allow realization of the target spectral efficiency and user fairness requirements. The integration of NOMA in the widely adopted orthogonal frequency-division multiplexing (OFDM)-based VLC networks would require an optimal resource allocation for the pair or the cluster of users sharing the same subcarrier(s). In this paper, the max-min rate of a multi-cell indoor centralized VLC network is maximized through optimizing user pairing, subcarrier allocation, and power allocation. The joint complex optimization problem is tackled using a low-complexity solution. At first, the user pairing is assumed to follow the divide-and-next-largest-difference user-pairing algorithm (D-NLUPA) that can ensure fairness among the different clusters. Then, subcarrier allocation and power allocation are solved iteratively through both the Simulated Annealing (SA) meta-heuristic algorithm and the bisection method. The obtained results quantify the achievable max-min user rates for the different relevant variants of NOMA-enabled schemes and shed new light on both the performance and design of multi-user multi-carrier NOMA-enabled centralized VLC networks.

Long-Term Evolution (LTE)

Data Mining ◽  
2013 ◽  
pp. 336-365
Author(s):  
Bing He ◽  
Bin Xie ◽  
Sanjuli Agrawal ◽  
David Zhao ◽  
Ranga Reddy
Keyword(s):  
Cellular Networks ◽  
Orthogonal Frequency Division Multiplexing ◽  
New Technologies ◽  
Network Capacity ◽  
Long Term Evolution ◽  
High Data ◽  
Term Evolution ◽  
Input Multiple Output ◽  
Speed Up

With the ever growing demand on high throughput for mobile users, 3G cellular networks are limited in their network capacity for offering high data services to a large number of users. Consequently, many Internet services such as on-demand video and mobile TV are hard to be satisfactorily supported by the current 3G cellular networks. 3GPP Long Term Evolution (LTE) is a recently proposed 4G standard, representing a significant advance of 3G cellular technology. Attractively, LTE would offer an uplink data speed up to 50 Mbps and a downlink speed up to 100 Mbps for various services such as traditional voice, high-speed data, multimedia unicast, and multimedia broadcasting. In such a short time, it has been broadly accepted by major wireless vendors such as Verizon-Vodafone, AT&T, NTT-Docomo, KDDI, T-Mobile, and China Mobile. In order for high data link speed, LTE adapts new technologies that are new to 3G network such as Orthogonal Frequency Division Multiplexing (OFDM) and Multiple-Input Multiple-Output (MIMO). MIMO allows the use of more than one antenna at the transmitter and receiver for higher data transmission. The LTE bandwidth can be scalable from 1.25 to 20 MHz, satisfying the need of different network operators that may have different bandwidth allocations for services, based on its managed spectrum. In this chapter, we discuss the major advance of the LTE and its recent research efforts in improving its performance. Our illustration of LTE is comprehensive, spanning from the LTE physical layer to link layer. In addition, the LTE security is also discussed.

scholarly journals The Total Network Capacity of Wireless Mesh Networks for IoT Applications

2020 ◽  
Vol 14 (08) ◽  
pp. 61
Author(s):  
El Miloud Ar-Reyouchi ◽  
Yousra Lamrani ◽  
Imane Benchaib ◽  
Kamal Ghoumid ◽  
Salma Rattal
Keyword(s):  
Wireless Mesh Networks ◽  
Forward Error Correction ◽  
Performance Metrics ◽  
Mesh Networks ◽  
Network Capacity ◽  
Operating Conditions ◽  
Wireless Internet ◽  
Research Issues ◽  
Wireless Mesh ◽  
Total Network

<p class="0abstract">Computing and measuring the total capacity of a data network are a remarkably difficult problem. These metrics are directly linked to the available bandwidth to each wireless internet of things (IoT) device of the network.  In this paper, the authors study the performance metrics associated with capacity traffic in multi-hop wireless mesh networks (WMNs). It is dedicated to Internet access assuming a time division multiple access (TDMA). They focus simultaneously on three key operating metrics, the total network capacity (TNC), total application network capacity (TANC), and the Average message time (AMS). They also analyze how parameters such as forward error correction (FEC) and acknowledgments (ACK) affect the overall network capacity under different operating conditions. Theoretical network capacity for WMNs, in this paper, is explored to draw attention to the number of open research issues</p>

scholarly journals Joint Channel Assignment and Routing in Multiradio Multichannel Wireless Mesh Networks: Design Considerations and Approaches

2016 ◽  
Vol 2016 ◽  
pp. 1-24 ◽  
Author(s):  
Omar M. Zakaria ◽  
Aisha-Hassan A. Hashim ◽  
Wan H. Hassan ◽  
Othman O. Khalifa ◽  
M. Azram ◽  
...  
Keyword(s):  
Wireless Mesh Networks ◽  
Channel Assignment ◽  
Mesh Networks ◽  
Network Capacity ◽  
Mesh Network ◽  
Future Research ◽  
Wireless Mesh ◽  
Traffic Distribution ◽  
Future Research Directions ◽  
Joint Channel

Multiradio wireless mesh network is a promising architecture that improves the network capacity by exploiting multiple radio channels concurrently. Channel assignment and routing are underlying challenges in multiradio architectures since both determine the traffic distribution over links and channels. The interdependency between channel assignments and routing promotes toward the joint solutions for efficient configurations. This paper presents an in-depth review of the joint approaches of channel assignment and routing in multiradio wireless mesh networks. First, the key design issues, modeling, and approaches are identified and discussed. Second, existing algorithms for joint channel assignment and routing are presented and classified based on the channel assignment types. Furthermore, the set of reconfiguration algorithms to adapt the network traffic dynamics is also discussed. Finally, the paper presents some multiradio practical implementations and test-beds and points out the future research directions.

Priority Scheduling Algorithm for Traffic in a LTE-based Defence Mesh Network Incorporating Centralised Scheduling Architecture

2017 ◽  
Vol 67 (5) ◽  
pp. 581
Author(s):  
Sidharth Shukla ◽  
Vimal Bhatia
Keyword(s):  
Packet Loss ◽  
Mesh Networks ◽  
Scheduling Algorithm ◽  
Data Rate ◽  
Mesh Network ◽  
High Data Rate ◽  
Priority Scheduling ◽  
High Data ◽  
Wireless Mesh

<p>Wireless mesh networks (WMN) are the networks of future and can operate on multiple protocols ranging from WiFi, WiMax to long term evolution (LTE). As a recent trend defence networks are incorporating off-the-shelf, state of the art commercial protocols to enhance the capability of their networks. LTE is one such commercially available protocol which is easy to deploy and provide high data rate which can be ideally implemented in WMN for defence networks. To enable these high data rate services LTE-based defence mesh networks (DMN) are the requirement of the day and future. However, LTE-based DMN are prone to congestion at times of active operations or full-fledged war. The congestion scenarios may lead to LTE packet loss. Hence, it is pertinent that these networks amalgamate information grooming algorithms to alleviate the throughput of the network in peak hour conditions. An efficient priority scheduling algorithm based on class of service prioritisation, data rate consumption and location of origin of traffic in the DMN is proposed. The simulations demonstrate that by incorporating the proposed priority scheduling algorithm, the overall packet loss of priority packets in the DMN reduces substantially.</p>

Analysis and Comparison of Routing Metrics for Multi-Interface Wireless Mesh Networks

2011 ◽  
Vol 268-270 ◽  
pp. 1856-1861
Author(s):  
Qi Ming Tian ◽  
Hao Yu Meng
Keyword(s):  
Wireless Mesh Networks ◽  
Performance Indicators ◽  
Mesh Networks ◽  
Network Capacity ◽  
Broadband Access ◽  
Routing Metric ◽  
Research Focus ◽  
Routing Metrics ◽  
Wireless Mesh ◽  
Wireless Broadband

The development of wireless broadband access in multimedia field has a higher requirement on wireless mesh networks’ performance. The design of routing metric is the key to improve the performance of wireless mesh networks. How to make full use of multi-interface technology in routing metric design to improve the network capacity has become a research focus. This article first analyzes the requirements of multi-interface wireless mesh networks on routing metric design, then analyzes strengths and weaknesses of nine routing metrics applied in wireless mesh networks currently, and finally compares the conditions of nine routing metrics capturing different performance indicators of wireless networks. As routing metrics like WCETT, MIC, WCETT-LB, IAWARE, ILA, MI and IDA all take channel interference problems into account, they are more suitable for multi-interface wireless mesh networks.

scholarly journals Max-Min Fairness in WMNs with Interference Cancelation Using Overheard Transmissions

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Mateusz Żotkiewicz
Keyword(s):  
Cost Function ◽  
Wireless Mesh Networks ◽  
Mesh Networks ◽  
Network Throughput ◽  
Test Cases ◽  
The Past ◽  
Wireless Mesh ◽  
Mip Model ◽  
Interference Cancelation ◽  
Maximal Throughput

We show an impact of using interference cancelation mechanisms for signals that have been overheard in the past on performance of fair wireless mesh networks. In our research we show that even in those very restricted conditions and max-min cost function, the idea of interference cancelation can significantly increase the capacity of such networks. In order to approximate possible advantages of using interference cancelation in the considered conditions, we propose a novel MIP model that allows for calculating perfect scheduling and maximal throughput in a network. We compare the results with cases when the interference cancelation mechanisms are disabled. Our results show that using interference cancelation mechanisms for signals that have been overheard in the past increases a network throughput by 40% on average in approximately 20% of test cases.

scholarly journals GPU Accelerated PIC and SIC for OFDM-NOMA

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 257 ◽  
Author(s):  
Talgat Manglayev ◽  
Refik Kizilirmak ◽  
Nor Hamid
Keyword(s):  
Interference Cancellation ◽  
Orthogonal Frequency Division Multiplexing ◽  
Multiple Access ◽  
Graphics Processing Unit ◽  
Processing Unit ◽  
Parallel Interference Cancellation ◽  
Central Processing ◽  
Fifth Generation ◽  
Access Scheme ◽  
Graphics Processing

Non-orthogonal multiple access (NOMA) is a candidate multiple access scheme for the fifth-generation (5G) cellular networks. In NOMA systems, all users operate at the same frequency and time, which poses a challenge in the decoding process at the receiver side. In this work, the two most popular receiver structures, successive interference cancellation (SIC) and parallel interference cancellation (PIC) receivers, for NOMA reverse channel are implemented on a graphics processing unit (GPU) and compared. Orthogonal frequency division multiplexing (OFDM) is considered. The high computational complexity of interference cancellation receivers undermines the potential deployment of NOMA systems. GPU acceleration, however, challenges this weakness, and our numerical results show speedups of about from 75–220-times as compared to a multi-thread implementation on a central processing unit (CPU). SIC and PIC multi-thread execution time on different platforms reveals the potential of GPU in wireless communications. Furthermore, the successful decoding rates of the SIC and PIC are evaluated and compared in terms of bit error rate.

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