South County ARES: Packet Radio

Background

Packet Radio is the standard digital transmission scheme for data interchange between amateurs at the local level. Police stations in the SCARES area of Belmont, San Carlos, Redwood City, Foster City, and San Mateo Area Office of Emergency Service have VHF packet stations operating on two meters. The convenience of "hard-copy" output and assurance of no errors from transmissions make packet radio a very attractive medium.

The Problem

Several county wide drills have attempted to demonstrate the packet radio capabilities; however with all stations trying to occupy the same spectrum, collisions were frequent and through-put times were exceedingly long.

An analysis of the problem county wide has led to these conditions as significant factors:

1. Operators were connecting direct to "county" and keyboarding the traffic.
2. All stations in the county were using the same frequency at the same time.
3. Stations "over the hill" in Half Moon Bay and Coastside could not reach "county".

The goal is to be able to send a message from any city EOC to any other city EOC within San Mateo County or to the San Mateo Area Office of Emergency Service in Redwood City. The solution must therefore be viable for all of San Mateo County.

The Solution

The solution to the problem has several facets involving a network, equipment, and operator training. First, the system must be disaster proof and be up on a 7 by 24 basis. A node or network would be needed to link north-bayside, south-bayside, and coastside regions. Any messages should be sent as files or "mail" with no keyboard to keyboard connects. Operators should not have to be concerned with routing of the messages, an address should be sufficient for delivery.

A TCP/IP network established by the ARES/RACES groups for San Mateo County Amateurs is the solution that was decided. This decision had other interesting consequences. The local governments are now establishing their own LANs and e-mail accounts, Amateur TCP/IP and internet gateway access would allow amateurs to send a message directly to the local city's e-mail system. Possibilities also exist to utilize the local city's LAN in an emergency as a gateway. Established e-mail protocol could be used for message creation and distribution.

It was soon realized coordination was required and several SCARES and ARES members from other sections of the County had discusions with the Stanford University Radio Club members who host the local gateway. With positive results from the Stanford meetings, a basic plan was generated to establish a node/switch on King's Mountain that would link the coastside communities to both Stanford and the bayside areas. IP addresses for the local towns were requested and the computers at the Police departments and County OES were outfitted with JNOS. Several ARES members started their own TCP/IP stations to gain familiarity with TCP/IP protocol.

The plan to start small and grow slowly was hastened by the fact that a county wide drill was coming up in a month (October '95). We didn't get the switch/node operational at King's Mountain but we did have three working station on 145.75 MHz the local 1200 Bd TCP/IP frequency. Belmont sent e-mail messages to County OES and was able to ping Redwood City PD. The SCARES TCP/IP station in Belmont PD also sent e-mail to the Belmont EOC via the Stanford gateway. The demonstration proved the system would work and that sending e-mail type messages was a comfortable and natural method. Operators chosen for the demonstration were familar with internet e-mail and TCP/IP which made for a smooth demonstration.

Things to be done:

1. King's Mountain:
   Complete the 145.75 MHz 1200 Bd Switch/Node at King's Mountain.
   Test King's Mountain switch software.
   Test the paths between Stanford, Coastside, North-bayside and South-bayside.
   
2. Backbone:
   Coordinate frequencies for a higher speed (>=9600 Bd) backbone.
   Establish a plan to move to 9600 Bd at the PD level.
   
3. Stations:
   Establish TCP/IP station at San Carlos PD.
   Link SCARES EOC computer to TCP/IP station in Redwood City via RS-232 line.
   
4. Training:
   Train the membership of the ARES groups on Packet TCP/IP and e-mail.
   

SCARES Internet addresses:

belmont.ampr.org.	44.4.20.1      (inactive)
kd6jtu.ampr.org.	44.4.20.14     (active)
sancarlos.ampr.org.	44.4.20.64     (inactive)
rwc.ampr.org.		44.4.20.128    (inactive)
smaoes.ampr.org.	44.4.20.160    (inactive)
kc6nyg.ampr.org.	44.4.22.98     (King's Mountain; inactive)
bbs.kc6nyg.ampr.org.	44.4.22.99     (Half Moon Bay; inactive)

SCARES TCP/IP Frequency:

145.75 MHz, 1200 Baud.