Inexpensive High Speed Packet Radio Is Here

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (ab9eh @ April 03 2002,13:58)</td></tr><tr><td id="QUOTE">What is the power limit on vanilla 802.11 boxes used by non-hams?  I would think that a regular Part 15 box with a high gain dish would give some serious range.  No?[/QUOTE]<span id='postcolor'>
Correct you can obtain 15-20 miles with true line of site within
Part 15 power limits.

Here is a power comparison

I just think we hams should be using this as an alternative to
existing 1200/9600 systems.

What better way to start using those unused bands?

 

There really is no excuse not to try something on 2.4GHz. The 802.11 info on the net is endless. Here is a plan I found for a homebrew 6dBi gain 2.4 GHz Colinear Omnidirectional Antenna

RM

 

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (kb9mwr @ April 03 2002,20:28)</td></tr><tr><td id="QUOTE"></span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (pyr @ April 01 2002,18:51)</td></tr><tr><td id="QUOTE">I've seen proxim's products go 17miles with a parabolic antenna for 100mbps. This things operate in the 5.4GHz band like 802.11a (but not complient). I hope someone finds a way to carry such a signal. reading 10Mbps microwave link. I was thinking of what kind of modulation you could use (like proxim) and any transmitters that would be able to handle such bandwidth?

KD5NQD[/QUOTE]<span id='postcolor'>
Our Proxim cards are 2.4 GHz, FHSS (Frequency Hopping Spread Spectrum) with +23 dBm output power stock.  They have a 1.6 Mbps signalling rate.  The Symphony's use 2 level FSK at 800 kbps, and 4 level FSK at 1.6 Mbps FHSS, 79 channels each with about 1 MHz bandwidth stock.  The default frequency hopping time is 200 milliseconds and is changeable. Frequency hopping systems are based on conventional narrowband radio technology.  This allowed us to use standard test equipment to check the RF sections.  We designed 1 watt Bi-directional amplifer using RF-microdevices RF2126.



More info click here[/QUOTE]<span id='postcolor'>
I get the 2.4GHz cards but I was mainly refering to the Stratum 100 wireless system in my original post.

 

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (mdown @ Mar. 30 2002,00:10)</td></tr><tr><td id="QUOTE">I have a question for the ham do-it your selfers. How hard would it be to modify a part 15 2.4 GHz device to be in the 2.3 GHz band?[/QUOTE]<span id='postcolor'>

It should be possible, there are a few people currently working on transverting the 2.4 GHz signal down to the 1.2 GHz or 900 MHz bands. No hardware exists currently, it's all just scribbles in a notebook for now.

Here is a theoretical overview of a 2.4 GHz to 900 MHz wireless LAN transverter

 

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (n1aup @ April 02 2002,11<!--emo&:0)</td></tr><tr><td id="QUOTE">Why can't hams replace these low power transmitter / receiver combinations with higher power ham radio, microwave equipment and decent antennas?

What if ham radio could provide 100 megabit, wireless, internet backbones connecting every state in the union to take over for the internet in times of national emergency? We could interface this backbone mesh with the computers of emergency service personnel running TCPIP with no reconfiguration of the computers themselves (by using the 802.11B equipment as the interface between the local network / computers and the ham radio WAN backbone.

I hear that the Linksys wireless access point boxes use the standard PCMCIA wireless card inside as the radio portion of the technology, so it might not be too difficult to replace the radio piece with something better.

Please don't tell me why this won't work. I'm very skilled at coming up with 1000s of reasons why this idea is far-fetched. Please tell me intelligent reasons how we can make this happen.

If ham radio can develop this communications system, it would rescue ham radio from extinction.

Is anyone else excited about this?[/QUOTE]<span id='postcolor'>


The main problem is the old, senile hams who control the local amateur packet networks. Most of these people have never heard of Claude Shannon, and think 1970's bipolar Motorola radios and 1200 bps AFSK is the way to go.

Example, one of the local packet "gods" told me I couldn't TX/RX switch 10 Watts @ 900 MHz in under 100 microseconds for one of our 2 Mbps links. Guess what? I've got the hardware to switch at around 40 microseconds. It's these egotistical ways which are killing modern packet radio.

 

You guys are making this too simple. Actually, Part 15 regulates the ERP, not the raw power output. Therefore, if you stick a high gain antenna on, it will violate the max ERP limitation.

Also, somebody here mentioned that these devices are spread spectrum. If thats true, then you wouldn't be able to just stick this thing on the ham bands with a minor modification. Spread sprectrum devices pseudo-randomly switch between many different frequencies, eating up a lot of bandwidth.

Also, somebody said that you would have to CW ID your wireless LAN card every 10 minutes. Thats bogus-- you don't have to do that with packet radio today! All you have to do is have your call sign on each packet.

Which brings me to my final point.... You wold have to adapt these things to use AX.25 so that the callsign routing system is retained without WEP encryption. Good luck on doing that with a highly integrated SMD constructed device with embedded microcontrollers. I know that regular ethernet uses a MAC address for identification....Wireless ethernet might use the same MAC addressing scheme.