D-Star DD 128kbps

• Mobile to mobile
• Fixed to mobile
• Optimised fixed (tall masts, optimum sites, high-gain beams)

Have you tried website browsing across it?

With regards to the various points:

• On VOIP over half-duplex - VOIP gateways can be configured to work over a single-hop or dual-hop satellite link, in which case there is significant satellite delay.  Surely half-duplex radio simply looks like 'delay' combined with a bit of of variable packet latency (which one would find on a contended network).  Have people tried using ID1's with VOIP gateways which either automatically detect and compensate for delay and latency - or allow you configure considerable delay/latency tolerance.

• On CQCQCQ - I understand that the radio doesn't understand IP when working point-t--point and is simply an Ethernet bridge.  When in DV mode, CQCQCQ allows any other radio to hear the call and respond.  I assume/hope that in DD more the same logic applies - so that an ID-1 with CQCQCQ programmed in as the station to be called would simply transmit all the Ethernet packets that arrive.  The issue will be over-the-air collisions.  In any case, it should be easy for ICOM to modify the ID1's microcode to allow it to operate in multipoint bridge mode, and to cope with over-the-air collisions.  Has anyone with access to three ID-1's tried this?

• With regards to the ID-1's TX duty cycle - I would actually convert this into Sale of Goods / Consumer protection issue.  Being amateur radio, by detault we are Consumers and the sale of goods act and consumer protection act apply, so that if a radio sold for the purpose of digital data transmission burns out after a few hours of digital data transmission unless such limitations were made clear by the retailer at the time of sale, I would want it exchanged for a product that was of merchantable quality or my £700 back! Buy the radio using a credit card and the credit card company is jointly and severally liable, adding to your consumer protection.

• I am not a lawyer and this is posting does not contain legal advice

D-Star digital data offers only modest data rates and appears, from what others have said, to do little more than point to point bridged links.  IP as an add-on rather than the system being designed around IP networking?  Good facilities but nowhere near what can be done with wireless networks on 2.4GHz and above.  The big advantage with D-Star is the use of lower frequencies where longer links are more easily achieved.

We should be pushing the manufacturers to include data facilities and to encourage the enhancement of the IP networking capabilities within D-Star but this is not going to happen in the short term.  If we are looking for something that is available now, I’m not convinced that D-Star delivers at a technical level or in terms of value for money.

Wireless network technology ticks more of the boxes at this time but it’s not the answer to everything.  I don’t see it delivering 100 mile links or easily providing medium distance links amongst the hills or in to a control room set amongst other buildings.

In terms of spectrum, the most vulnerable bands are probably 1.3GHz and 2.3GHz so we need to make more use of both. 

I’ll admit that my experience of D-Star is zero and I work with data networks for a living.  My comments need to judged within that context!