Amateur Radio Emergency Services
Illinois ARES®
 
Amateur Radio Emergency Service®

State of Illinois
American Radio Relay League
 
  R. Patrick Ryan, KC6VVT
  Illinois Section Emergency Coordinator
 

APRS for the EMERGENCY

The Illinois ARES may use APRS in the emergency to send bulletins statewide.

    The use of Automatic Packet Reporting System as developed by Bob Bruninga WB4APR has many potential uses for the emergency.  Use of this tactical display of APRS equipped stations and mobiles, and the objects and their positions is a powerful tool for the emergency, and is encouraged in ARES® mobiles and bases. A well developed and growing network exitst in the Illinois Section.

USES:
    Tactical mapping of fixed and mobile stations in your locality.
     One-line text messages may be sent and received by APRS stations;
    Local or Statewide
bulletins addressed to BLN#IL by APRS can advise all APRS monitoring responders to any emergency or need.
    Responding APRS equipped units can "home in" on objects, stations or trackers using locations given.  
    Outgoing email addressed one line to EMAIL, with the message line containing email address and short text message
    Two way email for mobiles using  APRSLink via APRS messaging  via WinLink that allows brief by multi-line text in a formatted message.

    The APRS networks are dependent on the local APRS users and their good sense in using this single  national frequency
of 144.390 MHz in the best possible way. Users must avoid sending our regular packets beyond two digipeater wide hops (ALOHA system) except in the emergency, and we must take a proactive stance in this effort as good APRS users.

    In the Illinois Section, to prepare our APRS network for the emergency, we shall follow the latest recommended APRS techniques and adopt the method proposed for wide area digipeaters on this National APRS frequency of 144.390 MHz. Much discussion of this has appeared on the APRS special interest group reflector, and is summarized in the WB4APR web pages titled
Fixing the 144.39 APRS Network

    Henceforth, using these suggested ALOHA procedures and guidelines by WB9APR and others supporting best use of APRS
, all Illinois APRS digipeaters are strongly encouraged to consider and implement a primary alias of WideN-n
    Further,add an alternate state alias  for the emergency  in the SSn-N format (e.g. ILn-N
).
    Set
UIFLOOD IL,30,ID from WIDEn-N to use the SSn-N state format of  ILn-N, and none of the other State SSn-N constructs or WIDEn-N abuses enter our network or can QRM our users.
    Of more importance, local emergency traffic nets can hit every digi in the state (or our ARRL section) if needed with NO DUPES, no extra beacons and NO QRM to other section LANS. And again, this new STATE NETWORK on APRS limits the propogation of abuse and does NOT depend on user settings! 


Some specific recommendations encouraged are:
  •     Local R-W-T digis may support this concept by adding IL2-2 and IL2-1 to their UIDIGI alias list.
  •     Also change UIFLOOD SS,30,ID to ILn-N so we have an Illinois state network which reliably covers our state independent of N, but no further.
  •     During phase-out of WIDEn-N, just move WIDEn-N to the UITRACE parameter. Our Illinois digis that wish to remain WIDEn-N are encouraged to move that path to the UITRACE parameter for full path tracing and point of origin.
Once conversion throughout the Illinois Section is complete, here are some suggested APRS paths to be seen in this section.
USER:                               DIGIPATH suggestions
HOME STATIONS:...........  WIDE1-1, IL2-2        
LOCAL MOBILES:............ WIDE1-1, WIDE2-2
RANGING MOBILES:.......  WIDE1-1,WIDE2-2, IL2-2
INTERSTATE MOBILES:.   WIDE1-1, WIDE3-3

ARES, RACES, EOC's:.....  IL3-3 or as needed  for coverage within Illinois only

ARES® Notes on APRS:

APRS ALT
    All Illinois ARES® stations using APRS for local operations, including Search and Rescue, are strongly encouraged to consider the alternate frequency method to temporarily improve local reliability in the presence of QRM at the local digi by having their own input channel, such as 144.99 (+600 KHz from 144.39 MHz).
    ARES users during any emergency may need to set their APRS radio on 144.390 from simplex to a plus (+) offset. Especially useful for weak station and mobile or portable  trackers.
    Then a local emergency  APRS digipeater may be set  to the corresponding 144.990 with a minus (-) offset .  When this temporary
local digipeater hears a local unit packet on the APRS ALT,, it will cross digipeat back to 144.390 where everyone in the APRS network receives, and can fit the packets between the many packets on the regular frequency of the APRS network.
    This simple APRS ALT solution can improve APRS reliability! See how to double local reliability using this  ALT-channel input on your digi at APRS ALT channel and 
TEMPn-N

APRS ALERT
   Mobile users of the Kenwood TH-D7 or TM-D700 have a means to be alerted to other Kenwood mobiles active in their direct radio range. See APRS ALERT
   ARES-IL units, Hospitals, EOC and other EmComm fixed location users with these particular amateur radio models needing an APRS ALERT method to activate local responders should contact Illinois ARESat the email address below for suggestions on this subject.

updated 11/26/06

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