What are Data Modes
- What are Data modes?
- What do I need to get
- How does it work
What are Data Modes? If your old enough to remember old computer data modems, or have heard a facsimile machine, you will be familiar with the sound of the Datamodes. The datamodes are often known as Packet, which refers to packet switching between nodes on the network which is a shared network. There are many common uses of Packet switching that you will come across in everyday life, telephony, internet networks, wireless networks
If you are familiar with Internet Technology many of the words and concepts will be very very familiar. Bulletin Boards (not to be confused with Forums) these bulletin boards have more in common with C.I.X networks than the Web based forums we use today. Mailboxes which work exactly as email accounts do, the difference being that a lot of the interfacing is a little more primative (In some cases, and dependent on your client), Distributed networks which have more in common with Peer to Peer networks, messages are passed along between multiple nodes.
What do I need to operate packet radio? To operate packet radio you will need the following either a HF or VHF transciever and the appropriate antenna, a dumb terminal, a modem or TNC (terminal Node Controller). The Dumb terminal or computer (or in some cases now the Transciever may have one built in) is responsible for negotiating the network connections, formatting the code and connecting to the Bulletin Boards. Remember that running packet can be done on a foundation license but running a TNC with mailboxes and BBS's cannot.
How Does It Work? VHF Stations use modems that have speeds of between 1,200 and 9,600 bits per second, and use Bell 202 Modulation, HF Stations again use modems, these modems use Bell 103 and have a throughput of 300 bits per second. Both the VHF and HF use the PTT control to allow the modem to switch from Receive (RX) to Transmit (TX) These modems use PSK (Phase Shift Keying) to increase the data throughput. The Fastest Amateur modem is 1.2mb per second, excluding the 2.4ghz band that many will know is used for Wireless LAN's
This Covers the transport method, we will discuss the Protocols used in another FAQ.