scholarly journals Random access improvement for M2M communication in LTE-A using femtocell

2019 ◽  
Vol 9 (2) ◽  
pp. 1153
Author(s):  
Eric Sackey ◽  
Rajeev Paulus
Keyword(s):  
Access Network ◽  
Random Access ◽  
Frequency Reuse ◽  
System Capacity ◽  
Fractional Frequency Reuse ◽  
Negative Effects ◽  
M2m Communication ◽  
Extended Access ◽  
Inter Cell Interference ◽  
Complete Frequency

<p><span>When an area is highly populated with Machine-to-Machine devices and all these devices attempt to access the Random Access Network Simultaneously, congestion is created on the network which degrades the performance of the network to other users. In this paper, the researchers are seeking to improve network accessibility by deploying more Femtocell into the network. They engaged the use of Extended Access Barring to restrict the M2M devices from accessing the network via macrocell eNB when a minimum load threshold is attained, thereby preventing the macrocell eNB from being congested. Deploying these Femtocells underneath the macrocell eNB comes with the issue of Inter-Cell Interference which nullifies any gains made by this deployment. The researchers employed Fractional Frequency Reuse and Complete Frequency Reuse schemes to mitigate the negative effects of ICI to augment the throughput of the network, improve the system capacity and enhanced the user experience within the network.</span></p>

Dynamic Fractional Frequency Reuse (DFFR) with AMC and Random Access in WiMAX System

2012 ◽  
Vol 68 (4) ◽  
pp. 1871-1881 ◽  
Author(s):  
Zohreh Mohades ◽  
Vahid Tabataba Vakili ◽  
S. Mohammad Razavizadeh ◽  
Dariush Abbasi-Moghadam
Keyword(s):  
Random Access ◽  
Frequency Reuse ◽  
Fractional Frequency Reuse ◽  
Fractional Frequency ◽  
Wimax System

scholarly journals Throughput Analysis and Optimization of Multi-layer FFR-aided OFDMA Networks

2017 ◽  
Author(s):  
Jan Garcia-Morales ◽  
Guillem Femenias ◽  
Felip Riera-Palou
Keyword(s):  
Analytical Framework ◽  
Frequency Reuse ◽  
Fractional Frequency Reuse ◽  
Spectrum Utilization ◽  
Average Cell ◽  
Cell Edge ◽  
Mathematical Expressions ◽  
Inter Cell Interference ◽  
Very High ◽  
Ofdma Networks

In OFDMA networks, the use of universal frequency reuse plans improves cell capacity but causes very high levels of inter-cell interference (ICI), particularly affecting users located in the cell-edge regions.In order to mitigate ICI while achieving high spectral efficiencies, fractional frequency reuse (FFR) shows a good tradeoff between cell-edge throughput and overall cell spectral efficiency.Recently, multi-layer FFR-aided OFDMA-based designs, splitting the cell into inner, middle and outer layers have been proposed and studied with the aim of increasing the spectrum utilization and improving the user fairness throughout the cell.This paper presents an analytical framework allowing the performance evaluation and optimization of multi-layer FFR designs in OFDMA-based networks.Tractable mathematical expressions of the average cell throughput as well as the layer spectral efficiency have been derived for both proportional fair (PF) and round robin (RR) scheduling policies.

A Simulation Framework for the Evaluation of Frequency Reuse in LTE-A Systems

2014 ◽  
Vol 3 (2) ◽  
pp. 56-83 ◽  
Author(s):  
Dimitrios Bilios ◽  
Christos Bouras ◽  
Georgios Diles ◽  
Vasileios Kokkinos ◽  
Andreas Papazois ◽  
...  
Keyword(s):  
Mobile Communications ◽  
High Performance ◽  
Interference Mitigation ◽  
High Capacity ◽  
Frequency Reuse ◽  
Fractional Frequency Reuse ◽  
Simulation Framework ◽  
Power Efficient ◽  
Enhance Efficiency ◽  
Inter Cell Interference

Long Term Evolution Advanced (LTE-A) technology is considered as the most possible candidate for next generation mobile communications. LTE-A networks offer high capacity and are specified and designed to accommodate small, high performance, power-efficient end-user devices. Similarly to its predecessor LTE, LTE-A incorporates inter-cell interference mitigation methods in order to mitigate interference and to enhance efficiency in bandwidth usage. These methods include power and frequency allocation schemes that allow neighbouring cells and femtocells in heterogeneous networks to co-ordinately share and reuse available spectral resources, in order to avoid performance degradation for interference suffering cell-edge users. In this paper, the authors study the LTE-A multi-cell systems' performance using a simulation framework, which integrates several frequency reuse techniques and provides a user-friendly graphical presentation of the evaluation results. The optimal Fractional Frequency Reuse (FFR) configuration for the user-defined network instance is also determined, based on overall performance and fairness index metrics. Finally, the authors examine FFR techniques in two-tier femtocell/macrocell environments and evaluate them based on the optimization of different metrics, depending on the network operator's needs.

scholarly journals An Improved LTE RACH Protocol for M2M Applications

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Ahmed Samir ◽  
Mahmoud M. Elmesalawy ◽  
A. S. Ali ◽  
Ihab Ali
Keyword(s):  
Success Probability ◽  
Random Access ◽  
Cellular Systems ◽  
M2m Communication ◽  
M2m Communications ◽  
Access Delay ◽  
Access Channel ◽  
Extended Access ◽  
Multiple Devices ◽  
Baseline Solution

Machine-to-machine (M2M) communications allow multiple devices to communicate directly without human intervention. There will be a huge number of devices in the M2M communications which results in enormous congestion in the current Random Access Channel (RACH) of LTE based cellular systems. This paper presents a protocol for improving the performance of the LTE RACH for M2M applications. This protocol, the Distributed Queuing Access for LTE (DQAL), is based on the Distributed Queuing (DQ) algorithm. One of the benefits of using that algorithm is minimizing the collision in the access phase for the M2M communications. The reduction in the collision will turn in enhancing both the access success probability and the access delay for M2M devices (MDs). Furthermore, the protocol is designed to guarantee that the normal User Equipment (UE) device can access the system using the traditional RACH procedures without any modification. This will assure a seamless implementation of the proposed protocol over the existing LTE cellular systems. The simulation results show how the access delay obtained by the proposed DQAL protocol outperforms the Extended Access Baring (EAB) which is the baseline solution recommended by the 3 GPP for M2M communication.

scholarly journals Hungarian Mechanism based Sectored FFR for Irregular Geometry Multicellular Networks

2021 ◽  
Vol 9 (2) ◽  
pp. 313-325
Author(s):  
Rahat Ullah ◽  
Zubair Khalid ◽  
Fargham Sandhu ◽  
Imran Khan
Keyword(s):  
Cellular Networks ◽  
Frequency Reuse ◽  
Fractional Frequency Reuse ◽  
Fractional Frequency ◽  
Achievable Throughput ◽  
User Simulation ◽  
Sum Rate ◽  
Irregular Geometry ◽  
The Individual ◽  
Inter Cell Interference

The growing demands for mobile broadband application services along with the scarcity of the spectrum have triggered the dense utilization of frequency resources in cellular networks. The capacity demands are coped accordingly, however at the detriment of added inter-cell interference (ICI). Fractional Frequency Reuse (FFR) is an effective ICI mitigation approach when adopted in realistic irregular geometry cellular networks. However, in the literature optimized spectrum resources for the individual users are not considered. In this paper Hungarian Mechanism based Sectored Fractional Frequency Reuse (HMS-FFR) scheme is proposed, where the sub-carriers present in the dynamically partitioned spectrum are optimally allocated to each user. Simulation results revealed that the proposed HMS-FFR scheme enhances the system performance in terms of achievable throughput, average sum rate, and achievable throughput with respect to load while considering full traffic.

scholarly journals Study of Handover Techniques for 4G Network MIMO Systems

2021 ◽  
Vol 15 ◽  
pp. 10-16
Author(s):  
Jian-Sing Wang ◽  
Jeng-Shin Sheu
Keyword(s):  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Cellular Systems ◽  
Frequency Reuse ◽  
Fractional Frequency Reuse ◽  
Cell Edge ◽  
Network Mimo ◽  
Input Multiple Output ◽  
Inter Cell Interference ◽  
4G Systems

For the upcoming 4G systems, network multiple-input multiple-output (MIMO) and inter-cell interference coordination (ICIC) are two of key techniques adopted in 4G systems to mitigate the serious inter-cell interference (ICI) and improve coverage and cell-edge throughput. Network MIMO is referred to as coordinated multi-point (CoMP) in LTE-A. In this paper, we propose a simulation platform to analyze the handover issue for downlink CoMP transmissions in LTE-A cellular systems. Among the variety of ICIC strategies, we apply the widely adopted soft frequency reuse (SFR) and the fractional frequency reuse (FFR) schemes. Both schemes are based on the idea of applying a frequency reuse factor of one in cell-center areas, and a higher reuse factor in cell-edge areas. Therefore, the ICI is reduced at the expense of the available frequency resources for each cell.

scholarly journals Interference Avoidance Using Dynamic Frequency Reuse For LTE-A System

2018 ◽  
Vol 7 (3.7) ◽  
pp. 1
Author(s):  
Asif Reza ◽  
Md Rafiqul Islam ◽  
Khaizuran Bin Abdullah ◽  
Farah Raisa
Keyword(s):  
Long Term Evolution ◽  
Base Station ◽  
Simulation Software ◽  
Frequency Reuse ◽  
System Capacity ◽  
Fractional Frequency Reuse ◽  
Cell Edge ◽  
Term Evolution ◽  
Dynamic Frequency

To meet the increasing demand for spectrum in communication system, Long Term Evolution (LTE) system has been proposed. It allowed users to use a new and much wider spectrum comparing to the other previous technologies. To utilize the full capacity of the LTE system Frequency Reuse (FR) has been adapted. It is a promising aspect of transmission of high rate data stream with better system capacity and fading immunity in the modern Long-Term Evolution-Advanced (LTE-A) system. Fractional Frequency Reuse (FFR) is the commonly used frequency reuse technique to increase the system capacity. But the problem is, with introduction of FR, it also increases the Inter Cell Interference (ICI) of the system. The out of cell interference coming from the neighbouring e-NodeBs (eNB) as a result of using the same frequency band and they act as an interference source. This ICI decreases the system capacity, resulting in hampering of communication, browsing and in worst case no connection at all. This condition highly affects the users under a cell specially those who are located in the cell edge areas. To take care of this issue an approach called Dynamic Frequency Reuse scheme has been proposed in this paper to mitigate the interference thus increasing the system capacity. This scheme uses continuous assessment of resource allocation and choosing the best sub-band for the user with least interference. There is a sequential order to be maintained for the users with using off minimum Base Station (BS) transmit power. The cell edge area users are the primary concern in terms of increasing their service quality. MATLAB simulation software has been used to justify the theory that the proposed scheme is capable increase the capacity of the cell edge areas as well as the cell centre area user. The results achieved from the simulation also indicates that the proposed model can enhance the system capacity comparing to the existing FFR scheme.     

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