Feb'18

The IUP Journal of Telecommunications

Focus

The improved coverage and penetration of LTE and VoLTE have enabled the M2M and IoT infrastructure to experiment with the various innovative research areas and further explore new applications. Obviously, new research and development in such modern telecommunication networks opens the scope to explore the area of data security and reliability by improving the latency and crosstalk both at the system realization level and also at the circuit implantation level.

This issue includes four research papers primarily addressing the challenges faced in wireless networks to mitigate the data delay and outage issues in high speed local area networks to ensure acceptable QoS. The first two papers discuss the system design improvement strategy to reduce the access delay during LAN access and link performance improvements for a higher data rate. The next two papers consider the signal crosstalk reduction and avoidance strategies during VLSI system implementation.

The crowded hotspot serving for IEEE 802.11n requires efficient scheduling algorithms to ensure an acceptable QoS. The first paper, "Delay-Sensitive Smart Polling in Dense IEEE 802.11n Network for Quality of Service", by H Vishalakshi Prabhu and G S Nagaraja, presents a suitable polling mechanism to examine delay reduction during service access. The paper introduces a new polling algorithm to reduce the polling delay in a crowded WLAN hotspot to ensure a guaranteed QoS. The simulation analysis provides a significant delay reduction and also an improvement in data throughput.

The emerging next-generation wireless networks support a very high data rate with a minimum end-to-end latency at a lower infrastructure cost. These networks employ massive MIMO (mMIMO) systems exploiting the inter-antenna correlation and non-orthogonal waveform based concepts to receive the signal quality to meet the standard specifications. The second paper, "Massive MIMO Challenges and Emerging Research Directions: A Review", by Ankita Sahu, Manish Panchal and Rekha Jain, is a review elaborating different design and implementation strategies used in a mMIMO system. Various limitations are reviewed to resolve the shortcomings of the evolving 5G wireless networks. Usually, in highly correlated channel vectors, the number of required antennas for mMIMO implementation increases the complexity of the design and then appropriate scheduling technique becomes an important strategy to separate the spatially correlated users.

The hardware circuit design and VLSI circuit implementation also plays a crucial role in deciding the overall end-to-end delay during high speed data transmission. In such cases, the transient behavior of data transmission circuits plays a deciding role by introducing unwanted signal distortion and crosstalk. The third paper, "Design and Implementation of Crosstalk Avoidance Using Bit-Stuffing Algorithms in VLSI Circuits", by B Jyothi and B Obulesu, proposes a parallel bit-stuffing algorithm with rate balancing for the VLSI circuits of high speed buses to eliminate crosstalk significantly. Parallel bit-stuffing algorithm with rate balancing not only achieves a higher coding rate but also consumes less power. The paper also proposes theoretical and simulation analysis of the proposed bit-stuffing algorithms to reduce the crosstalk, delay and power consumption.

The last paper, "Implementation of Crosstalk Avoidance and Low Power Coding Scheme for SoC", by D Chakradhar and B Obulesu, proposes a coding scheme for avoiding crosstalk and reducing power consumption in a System-on-Chip (SoC) bus. Usually, capacitive crosstalk and high power consumption are the major issues in such SoC buses and thus needs much attention to model, estimate and eliminate. Verilog encoder and decoder have also been proposed to avoid such problems in System-on-Chip (SoC) designs.

-V K Chaubey,
Consulting Editor

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Article   Price (₹) Buy
Delay-Sensitive Smart Polling in Dense IEEE 802.11n Network for Quality of Service
50
Massive MIMO Challenges and Emerging Research Directions: A Review
50
Design and Implementation of Crosstalk Avoidance Using Bit-Stuffing Algorithms in VLSI Circuits
50
Implementation of Crosstalk Avoidance and Low Power Coding Scheme for SoC
50
     
Contents : Feb'18

Delay-Sensitive Smart Polling in Dense IEEE 802.11n Network for Quality of Service
H Vishalakshi Prabhu and G S Nagaraja

In this paper, the polling mechanism of IEEE 802.11n standard is examined with the objective of reducing the delay induced by polling a large number of stations in crowded hotspot. This standard, also known as high speed Wireless Local Area Network (WLAN), is competent to become carrier Wi-Fi in the Evolved Packet Core (EPC). Scheduling algorithms are playing a major role in yielding QoS in high speed wireless networks of next generation. IEEE 802.11n standard has some support for Quality of Service (QoS)-based scheduling, but one that focuses on polling is not dealt with much in detail. Polling is a centralized scheduling which is initiated by the Access Point (AP) to poll user stations. Most of the proposed polling mechanisms introduce delay when the number of stations under a given access point increases. The aim of this paper is to introduce new polling algorithm based on two-level priority queues to reduce the polling delay in a crowded WLAN hotspot. This in turn assures the QoS guarantees for delay-sensitive applications. The new algorithm is named as Smart_Poll. The paper also discusses the performance estimation of the proposed smart polling by comparing it with traditional polling.


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Massive MIMO Challenges and Emerging Research Directions: A Review
Ankita Sahu, Manish Panchal and Rekha Jain

Advancement in information and communication systems leads to next generation wireless networks that should support higher capacity and data rate, low end-to-end latency, low infrastructure cost and high energy efficiency. To support next generation requirements, 5G will be the most prominent network based on massive MIMO (mMIMO). mMIMO has multiple number of antennas that help to fulfill the requirements of 5G, but there are some issues like pilot contamination, hardware impairments, inter-antenna correlation due to space constraints and non-orthogonal waveform design that needs to be rectified for utilizing advantages of mMIMO sufficiently. The paper reviews the various limitations and relevant techniques to solve these shortcomings of 5G wireless network.


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Article Price : ? 50

Design and Implementation of Crosstalk Avoidance Using Bit-Stuffing Algorithms in VLSI Circuits
B Jyothi and B Obulesu

Crosstalk is one of the major problems in VLSI circuits of high-speed buses. To eliminate this problem, several types of coding techniques have been proposed in the literature. The paper aims at avoiding the opposite transition on any two adjacent wires. Sequential bit-stuffing algorithm and parallel bit-stuffing algorithm are studied. The problem in parallel bit-stuffing algorithm is that the code rates for even-numbered wires are significantly lower than those of odd-numbered wires. To solve the uneven rate problem, the paper considers parallel bit-stuffing algorithm with rate balancing, where padding of additional bits on odd-numbered wire with the help of 2 ' 2 crossbar switch with bar state and cross state is done. By doing so, even-numbered code rate becomes equal to odd-numbered code rate, then code rates become balanced. Parallel bit-stuffing algorithm with rate balancing not only achieves higher coding rate but also lowers power consumption.


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Article Price : ? 50

Implementation of Crosstalk Avoidance and Low Power Coding Scheme for SoC
D Chakradhar and B Obulesu

The paper proposes a coding scheme for avoiding crosstalk and reducing power consumption. System-on-Chip (SoC) buses are associated with delay, power and reliability problems. Capacitive crosstalk and high power consumption due to various capacitances are the major causes of this problem. Verilog simulation of encoder and decoder modules are designed to avoid these problems.


© 2018 IUP. All Rights Reserved.

Article Price : ? 50