Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84 exptools; site ihlpg.UUCP Path: utzoo!watmath!clyde!cbosgd!ihnp4!ihlpg!retzner From: retzner@ihlpg.UUCP (Retzner) Newsgroups: net.ham-radio.packet Subject: Re: General questions on packet Message-ID: <1392@ihlpg.UUCP> Date: Thu, 31-Oct-85 10:43:46 EST Article-I.D.: ihlpg.1392 Posted: Thu Oct 31 10:43:46 1985 Date-Received: Sat, 2-Nov-85 04:37:57 EST References: <1260@sphinx.UChicago.UUCP> Organization: AT&T Bell Laboratories Lines: 56 > 1) Where can I get lots of information about it? The only > documentation I have so far is the November CQ magazine. There have been some "introductory" articles in recent issues of QST. Detailed information is available, just not in one place. Here are some national organizations for possible sources: AMRAD P. O. Drawer 6148 McLean, VA 22106-6148 AMSAT 850 Sligo #601 Silver Spring MD 20910 301-589-6062 Tucson Amateur Packet Radio (TAPR) P. O. Box 22888 Tucson, AZ 85734-2888 ARRL Newington, CT 06111 > > 2) What is the maximum size of an AX.25 packet? > AX.25 is limited to 128 bytes of data in a packet. > 3) What plans are there for the next level of network software > to be add to the basic network layer of error checking > packet communications that has been provided by AX.25. > These plans are currently in the works. There are small groups all over the country looking into this, some are playing with their own implementations. This is one of the main concerns of TAPR now. > 4) Why has the FCC limited H.F. data transmission rates to 300 > baud? I'm aware of the the limits on 2 meters and above. > In a word, bandwidth. Higher baud rates (frequency response) requires more bandwidth. More sophisticated modem techniques could cram more data into the available bandwidth (i.e. 212a), but at higher costs. > 5) I'm particularly interested in H.F. (D.X.) packet radio. How > much success has been made on the long distance bands? > I'm aware of the digirepeater capabilities of most of the > packet boxes, however I'm thinking more of long distance > point to point transmission because of the sacrificed speed > that digirepeating inherently requires. > There are people using it. Some computer equipped sites have "gateways" that connect a VHF TNC to an HF TNC. Others have experimented with OSCAR satellites. Hope this is of some help to the net. Bill Retzner WB9QXJ ihnp4!ihlpg!retzner