THE WORLD OF FREE PACKET RADIO SOFTWARE IN AMSTERDAM
Info About Packet, Software, Test Reports, DLL Files, Modifications And Schematics
THE NL3ASD INFORMATION PAGES - WHAT IS PACKET RADIO AND HOW WORKS IT
Packet radio is more than just a way of communicating with another radio amateur.
Especially when the amateurs use programs that TCP/IP can, then an open world.
TCP/IP provides the amateur many more opportunities than is possible with simple packet.
There is the possibility to send all messages and just received the own computer, without logging.
At BBS These messages can be both local and global.
The sending and receiving of files or even entire sub directories is possible.
For reports about the longer distance, some programs also seek the shortest path to the other station and regular testing.
For stations, the amateur does not know the route, can be an existing route with frequent stations collected from other stations.
For example, a route table generated, which is (almost) comprising world.
When the packet radio network is ready a utopia so, then the packet radio network has become a combination of many LANs in a WAN. LAN = Local Area Network with the amateurs in the neighborhood. WAN = Wide Area Network with all the amateurs in the world.
There are amateurs, who claim that packet radio has nothing to do with the radio electric making experiments.
But where's ever worked with a large wireless network in the world ?
Are not always the radio amateurs, with new ideas and perfecting these ideas into something that only the commercial implementation to business and private use can come later.
Years Take FM, which now sits on every radio, now take the TV, which is now in every house is, besides, all wireless voice connections were already far ahead Wed 1 by amateurs in use.
Packet radio is a way to transfer from A to amateur amateur amateur B.
If B is not within reach of amateur A readable text than other amateurs to work as a repeater.
Because we work with a packet radio simplex connection.
We do not speak of repeater but digipeater.
For a connection may be used up to 8 digipeaters.
Also, there are protocols have been developed, in order of the compound, which is primarily for text is intended to be used for the sending and receiving of binary files.
The most widely used way of packet radio is by using a so-called TNC.
This is a Terminal Node Controller, containing software for a special version of the AX25 protocol, which has been adapted for the simplex radio link Amateur AX25 AX25.
The software was developed by the TAPR Tucson Amateur Packet Radio club, and distributed as public domain worldwide.
A packet consists of a header, which is who sends and sundry to whom and through which digipeaters.
Furthermore, there is also the length of the data field and the kind of packet.
The names of the stations in the header are the common nicknames of amateur stations.
Most stations operate with 1200 Baud signals only when someone has multiple transceivers will come faster modems.
The foregoing stores for clarity on broadcasting in the FM mode, for single sideband is usually used 300 Baud.
With FM is working on the bands above 28 MHz
In the Netherlands we use packets with a data field of up to 255 bytes.
The longer the packet, the greater the chance of a transmission error, then the packet is repeated, for packet radio ensures error free transmission.
The packets are smaller than the return relative to the total length of the packet header with the drops.
A packet length of 255 bytes usually gives the highest efficiency and lowest band use.
With many packet radio can operate on the same frequency, by which each station still waits to transmit a packet, a few seconds until the frequency is clear.
In those few seconds, can other stations that you do not hear their own broadcast packet.
The practice has shown than when there is at a frequency more than 5 connections are routed though this is reflected in the speed of the connection.
Other modes with Packet Radio: Unlike data traffic via a line connection, we use the amateur packet frequencies, where we still need to include in the packet the call sign of the station.
Therefore, we need the other modes for packet NetRom and CP/IP header AX25 always a place for the call signs.
SOURCE: THANKS TO KLAAS THE PE1OAP FROM APELDOORN IN THE NETHERLANDS
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THE WORLD OF FREE PACKET RADIO SOFTWARE IN AMSTERDAM
