Digital Radio - The Next Generation Is Here
Digital technologies now impact on every phase of communications and information processing. Coming into maturity with computers in the last century, digital technology is now wide spread and part of everyone’s daily life experience. The impact on amateur radio is no less dramatic.
Digital signal processing has become part of many radio transceivers with great improvements over the previous analogue technology. Transmission of digital signals is common through modulation techniques such as frequency shift keying (FSK), Audio Frequency Shift keying (AFSK) used in for instance Radio Teletype modes. More sophisticated modes, still digital in nature, include PSK31 allowing keyboard-to-keyboard communications using HF bands. These modes are mainly text and developments to expand the digital techniques to send data include Packet Radio.
The real bridge between radio stations exchanging data came with the integration of Internet into the system. Schemes such as Winlink, IRLP and Echolink brought about significant increases in the availability of communication between amateurs wherever they are located.
D-STAR (Digital Smart Technologies for Amateur Radio) is a digital voice and data protocol specification developed for use in amateur radio This is truly Digital Radio making use of a wide range of the benefits and tools of digital technology. The use of D-STAR requires D-STAR compatible radios which are available in the VHF and UHF amateur radio bands. D-STAR radios can be connected to the Internet . D-STAR is the result of research by our sister society, the Japan Amateur Radio League into digital technologies for amateur radio. The D-STAR terchnology is open and not limited to one manufacturerer but to date no other amateur radio equipment manufacturer has chosen to include the technlogy in its transceivers. D-STAR is now being introduced into all capital cities in Australia in a scheme initiated and supported by the WIA and ICOM. It has been already operating in Darwin for some time as a result of initiatives by local amateurs.
The value of D-STAR is its ability to transmit a great amount of images, text and document data in a short time – more than can be done with the other digital techniques available to amateurs.For signals above a minimum, the quality of the data received through D-STAR is better than an analog signal at the same strength. This ability to send large quantities of data is particularly valuable to emergency services in the event of a disaster.