scholarly journals Low-cost wireless mesh communications based on openWRT and voice over internet protocol

2021 ◽  
Vol 11 (6) ◽  
pp. 5119
Author(s):  
Nina Siti Aminah ◽  
Muhamamad Reza Ramadhani Raharjo ◽  
Maman Budiman
Keyword(s):  
Low Cost ◽  
Internet Protocol ◽  
Session Initiation Protocol ◽  
Mesh Network ◽  
Line Of Sight ◽  
Voice Over Internet Protocol ◽  
Remote Areas ◽  
Wireless Mesh ◽  
Set Up ◽  
Non Line Of Sight

Technology makes it easier for us to communicate over a distance. However, there are still many remote areas that find it difficult to communicate. This is due to the fact that communication infrastructure in some areas is expensive to build while the profit will be low. This paper proposes to combine voice over internet protocol (VoIP) over mesh network implemented on openWRT router. The routers are performing mesh functions. We set up a VoIP server on a router and enabled session initiation protocol (SIP) clients on other routers. Therefore, we only need routers as a means of communication. The experiment showed very good results, in the line-of-sight (LOS) condition, they are limited to reception distances up to 145 meters while in the non-line-of-sight (NLOS) condition, they are limited to reception distances up to 55 meters.

scholarly journals Rancang Bangun Voice Over Internet Protocol dan GSM Gateway Berbasis Raspberry Pi

2019 ◽  
Vol 5 (1) ◽  
pp. 55-64
Author(s):  
Ardi Windiarto ◽  
Kholilatul Wardani
Keyword(s):  
Packet Loss ◽  
Internet Protocol ◽  
Quality Of Services ◽  
Line Of Sight ◽  
Raspberry Pi ◽  
Voice Over Internet Protocol ◽  
Non Line Of Sight

Makalah ini membahas desain layanan jaringan komunikasi VoIP Server menggunakan Raspberry Pi sebagai alat komunikasi wireless. VoIP server berbasis Raspberry Pi menggunakan sistem operasi RasPBX. Di dalam sistem operasi RasPBX sudah ada software asterisk yang berfungsi sebagai softswicth. Client VoIP menggunakan zoiper sebagai softphone. Alat ini dilengkapi dengan fitur GSM gateway yaitu fitur yang dapat menghubungkan jaringan VoIP ke jaringan GSM. Fitur GSM gateway ini menggunakan modem GSM sebagai jembatan yang menghubungkan jaringan VoIP dengan jaringan GSM. Persentase keberhasilan panggilan VoIP ke VoIP, VoIP ke GSM, dan GSM ke VoIP mencapai 100%. Berdasarkan hasil pengujian Quality of services (QoS) pada panggilan VoIP ke GSM, dihasilkan rata-rata delay sebesar 12,11 ms yang termasuk dalam kategori kualitas baik, Troughput sebesar 0,151, jitter sebesar 0,052 ms yang termasuk dalam kategori kualitas baik, dan packet loss sebesar 0% yang termasuk dalam kategori kualitas sangat baik. Jangkauan maksimal antara client VoIP ke server agar komunikasi berjalan dengan baik adalah 100 meter dalam kondisi Line Of Sight (LOS). Pengujian dengan jarak 25 m dalam kondisi Non Line Of Sight (NLOS), masih menghasilkan komunikasi yang baik. Berdasarkan hasil pengujian kuisioner dari 30 pengguna, dihasilkan nilai MOS 3,88 yang termasuk dalam kategori kualitas cukup baik.

scholarly journals Low-cost SPAD sensing for non-line-of-sight tracking, material classification and depth imaging

2021 ◽  
Vol 40 (4) ◽  
pp. 1-12
Author(s):  
Clara Callenberg ◽  
Zheng Shi ◽  
Felix Heide ◽  
Matthias B. Hullin
Keyword(s):  
Low Cost ◽  
Line Of Sight ◽  
Depth Imaging ◽  
Material Classification ◽  
Non Line Of Sight

scholarly journals Analisis Quality of Services Jaringan VoIP pada VPN menggunakan InterAsteriks Exchange dan Session Initiation Protocol

Techno Com ◽  
2020 ◽  
Vol 19 (1) ◽  
pp. 1-11
Author(s):  
Agus Heriyanto ◽  
Lailis Syafaah ◽  
Amrul Faruq
Keyword(s):  
Quality Of Service ◽  
Internet Protocol ◽  
Session Initiation Protocol ◽  
Virtual Private Network ◽  
Quality Of Services ◽  
Voice Over Internet Protocol ◽  
Control Protocol ◽  
Point To Point ◽  
Private Network

Di dalam komunikasi Voice over Internet Protocol (VoIP) mengenal beberapa macam protocol tambahan selain protocol standar internet Transfer Control Protocol/Internet Protocol (TCP/IP), beberapa diantaranya adalah protocol Session Initation Protocol (SIP), Inter-Asterisk eXchange (IAX) dan H.323. Performansi perlu dijaga mengingat VoIP mempunyai kemungkinan melakukan berbagai cara kompresi untuk menciptakan efisiensi saluran dan pemilihan protocol yang tepat. Teknologi VoIP pada dasarnya tidak memiliki jaminan keamanan pada setiap komunikasi. Keamanan ketika melakukan komunikasi suara merupakan sesuatu yang sangat penting karena menyangkut privasi penggunanya. Penggunaan Virtual Private Network (VPN) merupakan salah satu solusi untuk menutup celah keamanan pada kasus di atas. Analisis yang dilakukan pada artikel ini adalah performa yang dihasilkan VoIP yang menggunakan protocol IAX dan SIP. Penelitian ini mengahasilkan kesimpulan bahwa performansi yang paling baik digunakan untuk membangun sistem komunikasi VoIP adalah protocol IAX dengan menggunakan sistem keamanan VPN Point to Point Protocol (PPTP) dikarenakan nilai Quality of Service (QoS)  lebih tinggi daripada protocol SIP dan juga terbukti lebih aman saat diterapkan sistem keamanan Virtual Private Network Point to Point Protocol (VPN PPTP).

Wireless mesh network data communications and reliability analysis for anti-theft application deployment in educational institutions

2019 ◽  
Vol 17 (3) ◽  
pp. 474-489
Author(s):  
Roger van Rensburg ◽  
Bruce Mellado ◽  
Cesar Augusto Marin Tobon
Keyword(s):  
South Africa ◽  
Mesh Networks ◽  
Low Cost ◽  
Mesh Network ◽  
Educational Institutions ◽  
Data Communications ◽  
Wireless Technology ◽  
Content Type ◽  
Wireless Mesh

Purpose The purpose of this study is to locally develop low-cost wireless mesh networks for reliable data communications to devices that prevent the theft of these devices in learning institutions of South Africa. Design/methodology/approach A network test-bench was developed where millions of packets were transmitted and logged between interconnected nodes to analyze the quality of the network’s service in a harsh indoor building environment. Similar methodologies in “big data” analysis as found in particle physics were adopted to analyze the network’s performance and reliability. Findings The results from statistical analysis reveal the quality of service between multiple asynchronous transmitting nodes in the network and compared with the wireless technology routing protocol to assess coverage in large geographical areas. The mesh network provides stable data communications between nodes with the exception of reliability degradation in some multi-hopping routes. Conclusions are presented to determine whether the underlining mesh network technology will be deployed to protect devices against theft in educational institutions of South Africa. Research limitations/implications The anti-theft application will focus on proprietary firmware development with a reputable tablet manufacturer to render the device inoperable. Data communications of devices to the network will be monitored and controlled from a central management system. The electronics embedding the system-on-chip will be redesigned and developed using the guidelines stipulated by the chip manufacturer. Originality/value Design and development of low-cost wireless mesh networks to protect tablets against theft in institutions of digitized learning. The work presents performance and reliability metrics of a low-power wireless mesh wireless technology developed in a harsh indoor building environment.

Design and Tests of Wireless Network for Heat Metering System

2012 ◽  
Vol 182-183 ◽  
pp. 614-618 ◽  
Author(s):  
Xiao Wang ◽  
Ru Jian Ma ◽  
En Ping Zhang
Keyword(s):  
Wireless Network ◽  
Wireless Mesh Network ◽  
Discrete Data ◽  
Wireless Transmission ◽  
Mesh Network ◽  
Network System ◽  
Remote Transmission ◽  
Wireless Mesh ◽  
Heat Metering ◽  
Set Up

A wireless self-organizing network for heat metering system is designed based on ZigBee in this paper. XBee-Pro module is used for terminal nodes. Such nodes set up wireless mesh network, collecting heating meter data on one hand and realizing remote transmission of data though setting up mesh network with Router and Coordinator. The test is showing that wireless network system based on XBee-Pro module is convenient to use, reliable to transmit data and applies to collect spot discrete data and wireless transmission and meet requirement of heating meter remote transmission, realizing informatization and automation of controlling and monitoring of heating meter system.

scholarly journals NLOS Identification and Mitigation Using Low-Cost UWB Devices

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3464 ◽  
Author(s):  
Valentín Barral ◽  
Carlos J. Escudero ◽  
José A. García-Naya ◽  
Roberto Maneiro-Catoira
Keyword(s):  
Low Cost ◽  
Estimation Error ◽  
Ultra Wideband ◽  
Line Of Sight ◽  
Distance Measurements ◽  
Indoor Location ◽  
Indoor Scenarios ◽  
Indoor Location Systems ◽  
Clear Line ◽  
Non Line Of Sight

Indoor location systems based on ultra-wideband (UWB) technology have become very popular in recent years following the introduction of a number of low-cost devices on the market capable of providing accurate distance measurements. Although promising, UWB devices also suffer from the classic problems found when working in indoor scenarios, especially when there is no a clear line-of-sight (LOS) between the emitter and the receiver, causing the estimation error to increase up to several meters. In this work, machine learning (ML) techniques are employed to analyze several sets of real UWB measurements, captured in different scenarios, to try to identify the measurements facing non-line-of-sight (NLOS) propagation condition. Additionally, an ulterior process is carried out to mitigate the deviation of these measurements from the actual distance value between the devices. The results show that ML techniques are suitable to identify NLOS propagation conditions and also to mitigate the error of the estimates when there is LOS between the emitter and the receiver.

Wireless mesh networks

2008 ◽  
Vol 14 (8) ◽  
pp. 401-403 ◽  
Author(s):  
Xinheng Wang
Keyword(s):  
Wireless Networks ◽  
Large Scale ◽  
Ad Hoc ◽  
Mesh Networks ◽  
Low Cost ◽  
Mesh Network ◽  
Self Healing ◽  
Large Area ◽  
Satellite Systems ◽  
Wireless Mesh

Wireless telemedicine using GSM and GPRS technologies can only provide low bandwidth connections, which makes it difficult to transmit images and video. Satellite or 3G wireless transmission provides greater bandwidth, but the running costs are high. Wireless networks (WLANs) appear promising, since they can supply high bandwidth at low cost. However, the WLAN technology has limitations, such as coverage. A new wireless networking technology named the wireless mesh network (WMN) overcomes some of the limitations of the WLAN. A WMN combines the characteristics of both a WLAN and ad hoc networks, thus forming an intelligent, large scale and broadband wireless network. These features are attractive for telemedicine and telecare because of the ability to provide data, voice and video communications over a large area. One successful wireless telemedicine project which uses wireless mesh technology is the Emergency Room Link (ER-LINK) in Tucson, Arizona, USA. There are three key characteristics of a WMN: self-organization, including self-management and self-healing; dynamic changes in network topology; and scalability. What we may now see is a shift from mobile communication and satellite systems for wireless telemedicine to the use of wireless networks based on mesh technology, since the latter are very attractive in terms of cost, reliability and speed.

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