scholarly journals Multipoint stable radio frequency long distance transmission over fiber based on tree topology, with user fairness and deployment flexibility

2020 ◽  
Vol 28 (16) ◽  
pp. 23874
Author(s):  
Chen Hu ◽  
Bin Luo ◽  
Wei Pan ◽  
Lianshan Yan ◽  
Xihua Zou
Keyword(s):  
Radio Frequency ◽  
Tree Topology ◽  
Long Distance ◽  
Long Distance Transmission

Field Study of Low-Energy Long-Distance Wireless Communication for IoT Application in Remote Areas

Mekatronika ◽  
2020 ◽  
Vol 2 (1) ◽  
pp. 52-62
Author(s):  
Kwai Yang Sak ◽  
Ahmad Najmuddin Ibrahim
Keyword(s):  
Radio Frequency ◽  
Long Range ◽  
Essential Element ◽  
Low Energy ◽  
Line Of Sight ◽  
Area Network ◽  
Structural Elements ◽  
Wide Area Network ◽  
Residential Areas ◽  
Long Distance

Long Range (LoRa) is a wireless radio frequency technology under the Low Power Wide Area Network (LPWAN). LoRa is able to communicate long range and low energy consumption. The communication range has become an essential element in the wireless radio frequency technology in the Internet of Things (IoT). The presence of LoRa is able IoT application performs in long communication distances with high noise sensitivity ability. People can operate, monitor, and do a variety of tasks from a remote distance. Therefore, this research aims to evaluate the performance of the LoRa connection between radio transceivers in remote locations. The different environment and structural elements affect the LoRa performance. This thesis will be supported by the experiment that LoRa communication in different environments and tests. This experiment tests in line of sight (LOS) and non-line of sight (NLOS). Two sets of LoRa parameters, including Spreading Factor (SF), Bandwidth, and coding rate, are tested in different environments. The experiment tests the LoRa performance in various aspects: received signal strength indicator (RSSI) and packet received ratio (PPR) at different coverage ranges. In addition, the LoRa performance is evaluated in university, residential areas and vegetation areas under similar temperature, weather, and time. The LoRa coverage distance in the vegetation area and university area is reached 900 meters in the LOS test. Still, the vegetation area's signal is more stable and able to receive weaker RSSI signals. The LoRa coverage distance in the NLOS test is shorter compared to the LOS test. NLOS test has only one-third of the LOS LoRa communication distance. It is due to the signal penetration on structural elements such as buildings and woods cause the signal power loss and only transmitting a shorter distance. The LoRa parameter with SF9, 31.25kHz bandwidth and 4/8 coding rate has a better coverage range and stable connection.

A Novel IoT-Based Method for Real-Time Detection of Spontaneous Leaks in Pipelines, Gathering Systems, and Offshore Risers

2021 ◽  
Author(s):  
Matthew Grimes ◽  
Nico Van Rensburg ◽  
Stuart Mitchell
Keyword(s):  
Signal Processing ◽  
Transmission Lines ◽  
Negative Pressure ◽  
Pressure Wave ◽  
Long Distance ◽  
Non Invasive ◽  
Long Distance Transmission ◽  
Offshore Production ◽  
Offshore Risers ◽  
Oil Gas

Abstract This paper presents on a non-invasive, IoT-based method for rapidly determining the presence and location of spontaneous leaks in pressurized lines transporting any type of product (e.g., oil, gas, water, etc.). Specific applications include long-distance transmission lines, gathering networks at well sites, and offshore production risers. The methodology combines proven negative pressure wave (NPW) sensing with advanced signal processing to minimize false positives and accurately identify the presence of small spontaneous leaks within seconds of their occurrence. In the case of long-distance transmission pipelines, the location of the leak can be localized to within 20-50 feet. The solution was commercialized in 2020 and has undergone extensive testing to verify its capabilities. It is currently in use by several operators, both onshore and offshore.

Analysis of steady-state stability of long-distance transmission systems

1978 ◽  
Vol 98 (4) ◽  
pp. 63-72
Author(s):  
Toshihiko Saito ◽  
Kozo Aratame ◽  
Hiromichi Sato ◽  
Jiro Nagasaka
Keyword(s):  
Steady State ◽  
Long Distance ◽  
Transmission Systems ◽  
Long Distance Transmission ◽  
Steady State Stability
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