Centralized Coded Caching for Wireless Networks with Heterogeneous Channel Conditions

Wireless networks operate under harsh and time-varying channel conditions. In wireless networks the time varying channel conditions lead to variable SINR and high BER. The wireless channel is distinct from and more unpredictable than the far more reliable wireline channel. {\em Cross layer feedback} is a mechanism where layers provide {\em selective} information to other layers to boost the performance of wireless networks. {\em Cross layer feedback} can lead to a tremendous increase in the performance of the TCP/IP stack in wireless networks, and an increase in the user's satisfaction level. However, it is possible that naive feedbacks (or optimizations) can work non-coherently; therefore, these can negatively effect the performance of the TCP/IP stack. In this paper, we holistically analyze each layer of the TCP/IP stack, and propose possible Cross layer feedbacks which work coherently. The proposed Cross layer feedbacks can greatly enhance the performance of the TCP/IP stack in wireless networks.

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6G Vision and Challenges: Complexity Analysis of M-MIMO Rate-less Based System with Various Pre-Coding Schemes

10.21203/rs.3.rs-416935/v1 ◽

2021 ◽

Author(s):

Mohsen El-Bendary

Keyword(s):

Wireless Networks ◽

Error Control ◽

Complexity Analysis ◽

Mobile Wireless Networks ◽

Fixed Rate ◽

Mobile Wireless ◽

Coding Schemes ◽

Channel Conditions ◽

Raptor Code

Abstract Due to the expected essential role of the rate-less digital fountain codes and Massive-Multi-Input Multi-Output (M-MIMO) techniques in the 5G and 6G mobile wireless networks, this paper investigates the performance of M-MIMO enhancing system employing the Raptor code. The proposed M-MIMO-Raptor code based system has been tested over the different wireless communications channel conditions with respect to the various Frequency Doppler (FD). The various promising technologies for the beyond 5G and 6G have been presented with focusing on the advanced error control techniques. The flexible adaptive interleaved pre-code based on the channel conditions is suitable for 6G mobile wireless networks which integrates the various environments of the communications. The complexity of the advanced and fixed code rate schemes is discussed. Several computer simulation experiments are carried out for evaluating the performance of M-MIMO-rate-less code system. These experiments prove the superiority of the presented wireless rate-less system compared to the fixed rate wireless system due to the improved results of BER and the throughput values which are utilized as a performance evaluating metrics. Theoretical analysis of the M-MIMO throughput proves the enhancing of M-MIMO utilizing the rate-less Raptor code and its applicability for the next mobile wireless networks generations.

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Towards Dependable IoT via Interface Selection: Predicting Packet Delivery at the End Node in LoRaWAN Networks

Sensors ◽

10.3390/s21082707 ◽

2021 ◽

Vol 21 (8) ◽

pp. 2707

Author(s):

Marc Guerrero ◽

Cristina Cano ◽

Xavier Vilajosana ◽

Pascal Thubert

Keyword(s):

Wireless Networks ◽

Data Collection ◽

Protocol Stack ◽

Control Plane ◽

Practical Application ◽

Packet Delivery ◽

Extensive Data ◽

Channel Conditions ◽

End Node ◽

Different Levels

Estimating channel conditions to predict packet delivery can be exploited as a powerful tool to ensure wireless networks dependability. In this article we explore the practical application of this idea from the end-device perspective, using the LoRaWAN protocol stack. We aim to understand if packet delivery can be estimated considering different levels of feedback at the end-device. For that, an extensive data collection campaign is carried out. Through an analysis of the obtained traces, we establish correlations between connectivity metrics at the end node and the fact that a packet is received at the gateway. The study is complemented considering different levels of feedback: (i) No feedback, (ii) enabling acknowledgements frames, and (iii) considering application/control plane data about the channel status at the gateway side. The results show that it is possible to estimate packet delivery in all the evaluated cases.

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