D-Star
D-star arrived in West Tyrone in the spring of 2008 when the West Tyrone Repeater Group took delivery of the first D-Star repeater and gateway to be commissioned in Ireland. The Group have three repeaters near Omagh in West Tyrone. GB3OM and GB3WT share the same site but the new repeater and gateway, GB7WT, are on a new site which should provide good coverage to the west of the Province and into Donegal. But what is this new D-Star technology? Is it another fad or is it here to stay?
D-Star stands for Digital Smart Techmology for Amateur Radio and was developed in 1999 by the Japanese Amateur Radio League working in conjunction with Japanese Universities and amateur radio suppliers. The objective was to advance the hobby into the digital age by developing an open standard that would allow "anyone" to design and produce digital interfaces and radios for the ham radio community.
D-Star has two modes, ie digital voice (DV) and high speed digital data (DD). DV modes allows the simultaneous use of voice and serial data and fits into a 12.5kHz channel. DD requires wide channels and is only used on 23cm.
The advantages of D-Star are many but it is the D-Star repeater on the gateway that gives the greatest advantage over analogue radio since it is able to form a wide area network and can track users last known location in the form of the last repeater and port the user was heard on. In this regard it is not dissimilar to the cellular telephone network and may be used to route calls to specific stations automatically.Other features include the ability to connect to reflectors (conferences), GPS position report to the web and echo test your position. Because the gateway has user access control, all users must be registered if they want to make full use of the D-Star facilities.
Because D-Star is digital the data stream sent over the air includes headers such as the route the data should take and where it has come from. Four values are used for routing and may be easily progrmmed into all of todays D-Star radios. These parameters are MYCALL, URCALL, RPT 1 and RPT2. MYCALL is normally your own callsign, URCALL is the destination ddress. RPT1 is the callsign of repeater deing accessed and RPT2 is used only if accessing a local port on a different band or connecting to a remote computer.
An article describing D-Star in some detail is available for reading/downloading here whilst an informative web site may be found by clicking here.
For those interested, the new Omagh D-Star repeater frequencies are input 430.600MHZ and output 439.600 with CTCSS tone of 110.9Hz for access.
Posted 13 June, 2010 21:34:39 GMT