Localised FM Digital Audio Broadcasting using WiFi Mesh Networks

Author(s):  
Ashvin Verma ◽  
Somesh Kar ◽  
Priyanshi Ahuja
2020 ◽  
Author(s):  
Ashvin Verma ◽  
Somesh Kar ◽  
Priyanshi Ahuja

<div>Digital Audio Broadcasting via FM radio transmission on the VHF-II Band remains widely in use despite advancements in other wireless technologies due to its accessibility, particularly in rural areas where CRS help facilitate cultural expression and aid local information delivery. Current CRS are expensive and power-intensive while remaining challenging to scale, especially across hilly environments and uneven terrain.</div><div><br></div><div>This paper first examines the need for a low-cost, scalable CRS in 2 regions, namely India and African countries, using recent social science literature and reporting. Then, we evaluate the performance of the proposed community radio mesh system for range, scalability, and transmission quality. The system consists of low-cost and modular FM transmitter units connected to each other via a WiFi MeshNet which is used to transmit digital audio signals from the hub node. Each transmitter unit then broadcasts this digital audio signal in the VHF-II band, supported by standard feature phones and other FM receivers. The transmitter units consist of COTS components running on open-source software.</div><div><br></div><div>The transmission quality has been analyzed using objective metrics such as Peak-Signal-to-Noise Ratio and interpreted from PSD spectrograms and the output of Discrete Fourier Transforms. While field trials and further research are necessary, the approach seems promising for rolling out mid-to-large scale community radio mesh systems.</div>


2021 ◽  
Author(s):  
Ashvin Verma ◽  
Somesh Kar ◽  
Priyanshi Ahuja

<div>Digital Audio Broadcasting via FM radio continues to be popular, even today, owing to its accessibility, especially in rural areas where even common feature phones and affordable radio receivers are able to freely receive both, mainstream and local vernacular transmissions without any subscription charge. Additionally, it is established that broadcasts undertaken at a local level can play an instrumental role in facilitating cultural expression and aiding information delivery at a local level However, local broadcasts via the current Community Radio Stations (CRS) are not only expensive but also unsuitable for remote, isolated regions with their rugged terrains. </div><div><br></div><div>The authors hereby propose a novel approach to help address these current problems through a distributed system for Digital Audio Broadcasting. Multiple FM transmitting nodes (using VHF II: 87.5-100 MHz) form a WiFi Mesh Network to receive digital audio signals to broadcast from 1 hub node. The components used are off-the-shelf, cost-effective, and modular. It is more cost-effective than current CRS systems for mid-scale local broadcasts, with essentially no data loss between the transmitter units in deployment. Additionally, unlike relays, an existing alternative, built-in redundancy in the system ensures reliability, and caching protects against minor network disturbances when recordings are being broadcast. This approach allows for flexible and efficient deployments with wide, precise and accurate coverage, notably remaining equally effective in areas with an uneven terrain, thereby expanding its potential applications. </div><div><br></div><div>Experiments involving the system were conducted by varying the audio samples and the conditions, for which the evaluation metrics included the PSNR, PSD spectrograms, DFTs, signal strength, and data transmission rate to gauge the transmission quality, range and scalability. Results included a moderate data rate of 12 mbits/s at a 100 metres separation with obstacles from the transmitter, which is sufficient for the broadcasting and fast caching of high-fidelity audio. </div>


2021 ◽  
Author(s):  
Ashvin Verma ◽  
Somesh Kar ◽  
Priyanshi Ahuja

Digital Audio Broadcasting via FM radio transmission on the VHF-II Band remains widely in use despite advancements in other wireless technologies due to its accessibility, particularly in rural areas where CRS help facilitate cultural expression and aid local information delivery. Current CRS are expensive and power-intensive while remaining challenging to scale, especially across hilly environments and uneven terrain. This paper first examines the need for a low-cost, scalable CRS in 2 regions, namely India and African countries, using recent social science literature and reporting. Then, we evaluate the performance of the proposed community radio mesh system for range, scalability, and transmission quality. The system consists of low-cost and modular FM transmitter units connected to each other via a WiFi MeshNet which is used to transmit digital audio signals from the hub node. Each transmitter unit then broadcasts this digital audio signal in the VHF-II band, supported by standard feature phones and other FM receivers. The transmitter units consist of COTS components running on open-source software. The transmission quality has been analyzed using objective metrics such as Peak-Signal-to-Noise Ratio and interpreted from PSD spectrograms and the output of Discrete Fourier Transforms. While field trials and further research are necessary, the approach seems promising for rolling out mid-to-large scale community radio mesh systems.<br>


2020 ◽  
Author(s):  
Ashvin Verma ◽  
Somesh Kar ◽  
Priyanshi Ahuja

<div>Digital Audio Broadcasting via FM radio transmission on the VHF-II Band remains widely in use despite advancements in other wireless technologies due to its accessibility, particularly in rural areas where CRS help facilitate cultural expression and aid local information delivery. Current CRS are expensive and power-intensive while remaining challenging to scale, especially across hilly environments and uneven terrain.</div><div><br></div><div>This paper first examines the need for a low-cost, scalable CRS in 2 regions, namely India and African countries, using recent social science literature and reporting. Then, we evaluate the performance of the proposed community radio mesh system for range, scalability, and transmission quality. The system consists of low-cost and modular FM transmitter units connected to each other via a WiFi MeshNet which is used to transmit digital audio signals from the hub node. Each transmitter unit then broadcasts this digital audio signal in the VHF-II band, supported by standard feature phones and other FM receivers. The transmitter units consist of COTS components running on open-source software.</div><div><br></div><div>The transmission quality has been analyzed using objective metrics such as Peak-Signal-to-Noise Ratio and interpreted from PSD spectrograms and the output of Discrete Fourier Transforms. While field trials and further research are necessary, the approach seems promising for rolling out mid-to-large scale community radio mesh systems.</div>


IEE Review ◽  
1992 ◽  
Vol 38 (4) ◽  
pp. 131 ◽  
Author(s):  
Henry Price

IEE Review ◽  
1992 ◽  
Vol 38 (6) ◽  
pp. 216
Author(s):  
Edward C. Forster

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