Flexible aggregation of channel bandwidth in primary rate ISDN

1989 ◽  
Author(s):  
J. W. Burren
Keyword(s):  
Channel Bandwidth

scholarly journals Investigation of the Scattering Noise in Underwater Optical Wireless Communications

Sci ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 27
Author(s):  
Behnaz Majlesein ◽  
Asghar Gholami ◽  
Zabih Ghassemlooy
Keyword(s):  
Wireless Communications ◽  
Optical Wireless ◽  
Clear Water ◽  
Optical Wireless Communications ◽  
Channel Bandwidth ◽  
Phase Variations ◽  
Transmission Link ◽  
Channel Dependent ◽  
First Time ◽  
Scattering Noise

In underwater optical wireless communications (UOWC), scattering of the propagating light beam results in both intensity and phase variations, which limit the transmission link range and channel bandwidth, respectively. Scattering of photons while propagating through the channel is a random process, which results in the channel-dependent scattering noise. In this work, we introduce for the first time an analytical model for this noise and investigate its effect on the bit error rate performance of the UOWC system for three types of waters and a range of transmission link spans. We show that, for a short range of un-clear water or a longer range of clear water, the number of photons experiencing scattering is high, thus leading to the increased scattering noise. The results demonstrate that the FEC limit of 3×10−3 and considering the scattering noise, the maximum link spans are 51.5, 20, and 4.6 m for the clear, coastal, and harbor waters, respectively.

scholarly journals Synchronization of Discrete-Time Chaotic Systems in Bandlimited Channels

2009 ◽  
Vol 2009 ◽  
pp. 1-12 ◽  
Author(s):  
Marcio Eisencraft ◽  
Renato D. Fanganiello ◽  
Luiz A. Baccala
Keyword(s):  
Discrete Time ◽  
Digital Filter ◽  
Feedback Loop ◽  
Chaotic Systems ◽  
Signal Propagation ◽  
Slave System ◽  
Spectral Content ◽  
Channel Bandwidth ◽  
System Synchronization ◽  
Transmitted Signal

Over the last couple of decades, many methods for synchronizing chaotic systems have been proposed with communications applications in view. Yet their performance has proved disappointing in face of the nonideal character of usual channels linking transmitter and receiver, that is, due to both noise and signal propagation distortion. Here we consider a discrete-time master-slave system that synchronizes despite channel bandwidth limitations and an allied communication system. Synchronization is achieved introducing a digital filter that limits the spectral content of the feedback loop responsible for producing the transmitted signal.

Research on the bit computation model for time variable channel bandwidth

2007 ◽  
Vol 12 (3) ◽  
pp. 442-446 ◽  
Author(s):  
Jian Zhang ◽  
Min Huang ◽  
Guoqiang Han
Keyword(s):  
Time Variable ◽  
Computation Model ◽  
Time Variable Channel ◽  
Channel Bandwidth

A Comprehensive Review on Wired and Wireless Communication Technologies and its Challenges in Smart Residential Buildings

2021 ◽  
Vol 14 ◽  
Author(s):  
Senthil Prabu Ramalingam ◽  
Prabhakar Karthikeyan Shanmugam
Keyword(s):  
Wireless Communication ◽  
Residential Buildings ◽  
Optimization Algorithms ◽  
Communication Protocols ◽  
Communication Technologies ◽  
Data Rate ◽  
Appropriate Technology ◽  
Security And Privacy ◽  
Electricity Cost ◽  
Channel Bandwidth

Background: The smart grid communication network is constructed with three tiers namely, Home Area Networks (HANs), Neighborhood Area Networks (NANs) and Wide Area Networks (WANs). These networks function with various communication protocols like table protocol, on-demand protocol, Wi-Fi, Zigbee, Z-Wave, Wi-MAX, GSM, LTE, Cognitive Radio Networks. The network interconnection is heterogonous and all appliances have to communicate through the IP gateways. A large amount of data is collected from various sensors placed in different locations. The analytics on large data- “big data” is essential because these data were used to organize and plan an efficient control and management of the smart home including secured data exchange in different sectors. Objective: This paper investigates broadly on data rate, channel bandwidth, power consumption, and a coverage range of both wired and wireless communication technologies used in residential buildings. Besides, a literature survey on optimization algorithms with various constraints to manage home appliances through scheduling is included. The paper also discusses the communication standards along with security and privacy requirements for smart metering networks. Conclusion: Discussion on IEEE standards for both wired and wireless communication protocols. Gives direction to identify the suitable communication technique through mathematical model for computing the communication channel bandwidth. Comparison of various optimization algorithms with multiple constraints in HEMS to achieve the minimum electricity cost and user comfort (with and without Renewable Energy Sources). From the investigation on both wired and wireless networks, the wireless communication networks (Zig-Bee & Wi-Fi) are mostly preferred to use in HAN because of more reliability and low cost. Zigbee is the most appropriate technology used for data transmission between the individual appliances and smart meters. Wi-Fi is a suitable technology for controlling and monitoring appliances because of its high data rate.

Probing based wireless channel bandwidth estimation and its application to video streaming over wireless networks

2008 ◽  
Author(s):  
Hyeong-Min Nam ◽  
Kyung-Seok Shin ◽  
Jae-Yun Jeong ◽  
Seong-Jun Bae ◽  
Sung-Jea Ko
Keyword(s):  
Wireless Networks ◽  
Video Streaming ◽  
Wireless Channel ◽  
Bandwidth Estimation ◽  
Channel Bandwidth

scholarly journals Results of work of new spectropolarimeter for solar radio emission observations in the range 50–500 MHz

2019 ◽  
Vol 5 (3) ◽  
pp. 3-10
Author(s):  
Наталия Муратова ◽  
Nataliia Muratova ◽  
Анатолий Муратов ◽  
Anatoliy Muratov ◽  
Лариса Кашапова ◽  
...  
Keyword(s):  
Radio Emission ◽  
Solar Radio ◽  
Block Diagram ◽  
Stokes Parameters ◽  
Solar Radio Emission ◽  
Digital Receiver ◽  
Stokes Vector ◽  
Digital Radio ◽  
Solar Observations ◽  
Channel Bandwidth

Ground-based observations within meter radio range are of importance for understanding processes occurring in the solar corona. We present concepts, block diagram, and results of first observations of the Solar Spectropolarimeter of Meter Range (SSMD), launched for solar observations in the range 50–500 MHz in April 2016. The main purpose of this work was to develop an up-to-date digital radio spectropolarimeter able to record the full Stokes vector for sporadic solar phenomena taking place in the 50–500 MHz range. We use a crossed log periodic antenna to detect solar radio emission. This antenna can simultaneously obtain horizontal and vertical polarization components. The main part of SSMD is a digital receiver based on an FX correlator architecture. We use the Fast Fourier Transform (FFT) algorithm based on the real-time pipeline circuit to construct amplitude dynamic spectra (intensity vs frequency and time). SSMD has 4608 frequency channels with 97.66 kHz channel bandwidth and 97.66 kHz spacing. Time resolution is 1 s. The spectropolarimeter has a 50–500 MHz range. It can record the full Stokes vector. At present, SSMD observes two of four parameters in regular mode (I and V). We have observational data since 2016. The catalog development is in progress. We plan to improve time and frequency characteristics, record all Stokes parameters, and conduct a calibration. We are working on providing access to the data archive via the Internet.

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