What EWN means to RACES

ARES/RACES drills quickly teach an appreciation for efficient traffic handling. Net control operators routinely sing songs of happiness when messages are delivered by packet radio, error free in seconds without taxing the attention of net control.

But while Packet traffic is vastly more efficient than handling messages by voice, it does not scale well under high load situations like an incident response. Under high traffic conditions, throughput by packet drops considerably to <300 bytes per minute. With only three packet channels set aside for the whole of Santa Clara County, this is still only 1K, or one page per minute for 1.7 million people.

This is little surprise when taking into account that packet radio is as old as the 300 baud modem, and has not seen an upgrade since a decade before the World Wide Web was even invented due to bandwidth limitations by the FCC.

In contrast, the EWN transmits in full duplex between each node at a minimum of one megabit per second, sixty thousand times faster than loaded packet radio. To put that in perspective, you would have to run all three packet channels for nearly a day and a half to deliver as much traffic as the EWN would deliver in two seconds. And that is on a bad day for the EWN. In better conditions, it might transmit more like 10-20 days of packet information in those same two seconds.

There are no doubt still advantages to packet radio. For stations in obstructed ground level locations, packet makes a great low power, small package, portable solution, sufficient for low traffic demands. A neighborhood CERT post would be an excellent application. But at fixed base, traffic consolidation points like EOC's, hospitals, shelters, and utilities, the payoff justifies the infrastructure of an EWN.

-- Main.randomandy - 25 Aug 2009