Wifi and 500 km? Development of Wi-NVIS

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Networking and remote areas

This presentation is about the development of a device that can connect local (wifi) networks over a distance of more than 500 km.

Description

At this moment for rural access there's the only posibility is satellite IP connections. For distances up to 50 km, lets say 100 km, there are wireless solutions, beyond that there is only satelite communications.We took up the plan to develope a tactical shortwave radiosystem for rural and remote areas, capable delivering 64 Kbsec over distances, more than 500 km as an addition to Wifi/Wimax posibilities which end at 50 km.

Research

Investigations in existing development in this area brought after nearly a year of extensive search and research, the conclusion that only the military are working on a similar project. Portable multimedia for the battlefield called JTRS (Joint Tactical Radio System). This system should provide multimedia to the battlefield no matter where. Until now the military are the only ones working on a realy independent wide range connecitivity system.

Technology

We're building a device using shortwave (30 Mhz an below) multislotted radiosystems. The radios work with digital signal processing and advanced serial modulation using soundcards, up to 128 kbs per canal over N(ear) V(ertical) I(ncedent) S(kywave). Wifi is used for space division between shortwave nodes. The device will be 'intelligent, meaning that it chooses the best frequencies and, using load balancing, route via the nodes with the best propagation. For the the node operators this process is automatic and transparant.

Cooperation

Oftelsat works together with people in the United States building the Software Designed Radio SDR1000. With SDR computer hardware can be used as radio hardware. The SDR uses software digital signal processesion,which will in the future be part of wifi and wimax devices. Parallel processing makes posible more bandwith and a higher bitrate.

We are looking for more cooperation. Knowledge is not widespread and a lot of work need to be done. People with experience in Digital Signal processing (DSP) and/or DSP programming tools (digital signal generation, filtering and demodulation of complex waveforms) as well as people with organisational and communication skills are welcome. Furthermore, most tools for digital signal processing are very expensive, so also fundings we could use. But when we get it functional we think there's no discussion about how such a tool could help in building connectivity.

Goal

Our goal is mobile and fixed wireless IP-connectivity at distances up to 1000km. This year 2005 we want to get ready the first prototype of a wireless, software based, open source, multislotted connectivitydevice, with minimum 64Kbs throughput.

Development Wi-NVIS or cognitive radio model

First stage:

The first step is to build a voice data link between Esmeraldas, a remote location in Ecuador, without existing connection posibilities and the city of Guayaquil 300 km to the south. We want to have that link up for two weeks. A third connection in the experiment is from Quito, mobile and fixed, to Esmeraldas and Guayaquil. Before WTH we start with this NVIS digital data and voice experiment. So hopefully we can show on WTH an echolink (voice over IP) via the internet to the Wi-NVIS, radio gateway.

We start the experiment with 3Khz and 3Kbs (IP) data, not much bandwidth, but if we join later say 10 channels, the image will change.

The used hardware: 2 stations and 1 fixed/mobile station in Ecuador. A station consits of one PC, a soundcard used as modem, a HF, IC 706 tranciever, a special ARD9800 voice data modem and some hardwareinterfacing. The software is mostly propietary at this moment, because an open source alternative does onlyexist for some parts, but nothing integrated.

The shortwave link will (below 14Mhz) be build with automatic link establishment (ALE) and some interfacing. The software can automatically find an alternative frequency if necessary to sustain the best link. We call it Wi-NVIS. If this works we try to make an IP-link of 3000 bs to a ADSL gateway in Quito.

Second stage:

Replace the Icom 706 radio with Software Defined Radio (SDR)

Third stage:

Multiplex to 64Kb.

Last stage:

System integration and use of opensource software

In the future this link will be used for a cacao production project from the MCCH, a strategic partner of Oftelsat and partner organisation of the roundtable, an initiative of the IICD in Ecuador.

Speakers

• Karel Fassotte

Schedule

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