D-Star
D-Star
February 2008 Meeting.
A general meeting of the VHF Group was held at the club rooms Hazel Avenue on February 11th 2008. It was very well attended by over 30 people. A very pleasing result given the short notice that was necessary due to a change in the program.
The core of the presentation asked the question as to what Civil Defence organisations need in today's world especially during an emergency, and can Amateur Radio provide that service over the "Broken Mile".
The "broken mile" was defined as the disaster zone where power, telephone, network and general infrastructure services have been disrupted or destroyed. What is needed by Civil Emergency Organisations is to transfer large amounts of Data and information to many places at the same time, so that strategic planning and coordinated efforts can be rapidly put into action, based on the information coming out of the disaster area. The idea is that teams go into these zones equipped with lap-top computers, all having standard type IP based browsers and software, and they want interconnection to the outside world quickly.
The message was simple. The old style of message handling by voice, AX25 packet, and any other of the traditional Amateur Radio methods just does not hack-it. The thing to remember is that when the Balloon goes up, "its there party and we want to be invited!" If we don't have the means available, the use of Amateur Radio in emergency scenarios is very limited. So how do we make it happen?
Fortunately, in 1999, JARL in association with ICOM came up with a solution using Digital Radio Techniques. Called D-Star, the system has the very solution we have been looking for. It provides for an IP Based digital Data network that can be connected into the Internet via a port. Data speeds are good provided the higher frequencies are used. Links between repeater sites can be accomplished in the 10GHz band, providing a back bone network capable of 10MBs. Normally this back bone would be coupled into the Internet.
The repeaters can be on 1296, 460 or 144MHz. They link into the back bone network. Our option is to initially use the 1296 band because this gives us the faster base to repeater link speed of 128KBs, - and also helps populate the band! The system allows us to have a VPN (Very Private Network) as we do now with our traditional Amateur Radio system, and also allows us to connect to other D-Star systems via the internet, (a bit like IRLP) with station to station calling and a whole heap of other useful features. More importantly, it allows us Amateurs to provide the all important Data connection for the Civil Defence and Emergency services, over the "broken mile".
The committee had recommended to the members at the meeting that we proceed with a fund raising campaign of $50,000 for the purposes of purchasing and installing an initial 10GHz backbone network within the Auckland Region, and for the purchase of a quantity of ID1 sets and repeaters to work into that network, with the aim that over time the network would be expanded as funds allowed. The motion was supported from the floor with a motion that the committee investigate ways to raise the necessary funds. The vote was in favour unanimously. The committee have started work.
John Dunn
ZL1JD
President of the Auckland VHF Group Inc.
For More information see.
IP connectivity
The aim is to provide IP connectivity via Ham radio. There for I am looking at a number DD mode DSTAR repeaters. The plan is for three coverage areas in and around Auckland. At this point in time they're no planes for DV mode. The feedback I am getting from VHF group is that we have good coverage with our 2 meter FM repeaters.
Zone A Auckland city
Zone B Klondyke north
Zone C Klondyke south
With a 10 GHz data link between the city and Klondyke. For a DD mode repeater we are looking for two half duplex frequencies for Klondyke. One could be around 1270 MHz and the other could be at 1290 MHz and one for Auckland city. When there becomes a need for a DV mode repeater. The plan is to use 2 meter or the 70 cm band.
DD mode repeater (Icom ID-RP2D)
A DD repeater operates on half duplex frequency in the 23 cm band. With a RF output power of 10 Watts.
Grant
ZL1WTT