APRS Freq Spec - AFRS (Automatic Frequency Reporting System) 18 Jun 10 ------------------------------------------------------------------------ WB4APR Revisions: 18 Jun 10 to clarify 1750 Wideband and l750 narrow (l/c "L") 22 Oct 09 to add WiRES objects 22 Jul 09 to add additional options for Echolink objects 15 Jun 08 to eliminate leading space in FREQ object 21 Feb 08 to add WIDE/NARROW and TONE/CTCSS 13 Dec 07 to updte IRLP beacon info 30 Sep 07 to include Mic-E Echolink format for D710 radio 16 Aug 07 to finalize format of leading SPACE character 1 Aug 07 to merge in IRLP & EchoLink nodes (was on AVRS pages) 21 May 07 to include unique ID's for repeater frequency objects 8 Oct 05 Ham radio's biggest advantage of thousands of frequencies is also its biggest stumbling block at rapidly and efficiently establishing com- munications under emergent or immediate need or just to chat on a long trip across country. Ham radio needs a way to determine the operating frequency of the other stations and applications around us or to send to a distant station, a desired contact frequency. This initiative came out of the Hurricane Katrina lessons learned. APRS, is a single resource for identifying and locating amateur radio operators on both a local and global scale. Over 30,000 stations world wide are currently in the system and you can view them in any area or near any station via any APRS client program or via any number of APRS web pages such as the following: http://www.jfindu.net OR http://map.findu.com/callsign* ... and then select "stations near". http://www.APRSworld.net But now also, we want to know their present operating frequency, or be able to send to them a desired contact frequency. The purpose of the AFRS initiative is to standardize so that we know their Tone, offset, and nominal range as well. These are the types of local objects that should show up on the mobile APRS display in every local area: Every mobile's (or fixed station's) operating frequency The locally recommended voice frequency for visitors The local IRLP or EchoLink node and current node status The local WinLink node and current node status The frequency of any Net in progress Any other local ham radio asset or net of interest to APRS mobiles KEEP IT LOCAL! These local frequency OBJECTS should ONLY be transmitted in the local RF area where they can be immediately used. Transmitting them any farther than DIRECT or one hop will just be SPAM in areas that cannot use them. The sources of these frequencies are as follows: * Mobiles typically put their operating frequency in their STATUS text * The local Voice Repeater object is TX'ed in the local DIGI's BText * IRLP, EchLink and WinLink objects are generated by their own software and injected into the APRS-IS. From there, each LOCAL IGATE SYSOP decides which IRLP and which Echlink and which WinLINK object is in his immediate area, and he then adds these specific individual objects to his pass-to-RF list via no more than a ONE-HOP-PATH... RECOMMENDED TRAVELERS VOICE REPEATERS: Every digi has a coverage area. It is the responsiblity of that digi to transmit an object showing the best recommended travelers voice repeater in that coverage area, DIRECT, once-every-10-minutes. Being direct (no digipeats), they are only received in the vicinity where they are usable. Also, by originating at the Digipeater's high site, there is no impact on the channel load, because the digi will not transmit until the channel is clear. See: http://www.aprs.org/localinfo.html WOTA, DX CLUSTERS, KATRINA: This AFRS Frequency initiative is working in parallel with the post-Katrina ARRL Initiative to provide operating frequency contact information in support of emergency response. Since the APRS-IS exists worldwide and already supplies information on all APRS stations, it can also accept data from WOTA, DX clusters and Logging programs to serve as a single resource for finding the likely operating frequency of interest for any station. ADDING FREQUENCY TO APRS: Already, APRS encodes the following information into typical user position packets. CALL, LAT, LONG, COURSE, SPEED (Grid is calculated) Station type (one of over 200 symbols) Antenna Height above average terrain Antenna Gain Comment (37 bytes max) (usually where stations have their frequency) Software version FREQUENCY has been added in a backwards compatible manner, as a fixed formatted field in the first 10 bytes of the existing free-field position comment text or STATUS field. In addition to these 10 fixed format bytes,(if used) there are additional optional format bytes to include additional amplifying information about tone, range, net and meeting times. This 10x10x+ format shows up well on the 10 byte displays of the D7, D700's and the HAMHUD. A typical entry might be: "FFF.FFFMHz Tnnn RXXm". The Tone and Range (XX miles or km) are optional or can be "Dnnn" for DCS coded squelch. MESSAGE FREQUENCY: Similarly we want to be able to send a freqency in a message to another station, and for his station to either manually or automatically change his voice radio to that contact frequency. FUTURE RADIO COMPATIBILITY: In response to this frequency initiative both Kenwood and Yaesu have released compatbile radios. The Kenwood D710 will automatically insert its frequency into its position text and on receipt, can parse it and automatically tune to that frequency with a single press of the TUNE button. The new Yaesu VX-8R also accomodates the 10x10x+ format on its 20x20 display for user friendly display. We hope eventually they will tune to either objects or messages with QSY information. See the Automatic Voice Relay System www.aprs.org/avrs.html LOCAL/GLOBAL VOICE CONTACT VIA CALLSIGN ALONE: One of the major initiatives for this frequency capability was to be able to set up end-to-end VOIP voice contact between amateur radio operators knowing only callsigns. By using APRS as the backbonen signalling system, Automatic QSY can be implemented and this, combined with APRS messaging and IRLP or EchoLink networks can lead to fully automatic end-to-end voice connectivity between APRS users anywhere on the planet with only the knowledge of a callsign. All it takes is a little software. But that is where we are headed with this. BACKWARDS COMPATIBILITY: It is also possible that some PC controlled radios could be outfitted with simple external PIC processor that can interrogate the radios via their serial ports and can then insert their frequency information into their position beacon. This could easily be added to the firmware of some of the existing APRS TRACKER devices. NATIONAL VOICE ALERT FREQUENCY: Presently, APRS operators already have a nationwide voice contact frequency called VOICE ALERT. This system for mobiles simply means that the APRS data radio is set to CTCSS 100 with the volume up. This mutes all packets, but allows the operator to be available for a voice call from anyone in simplex range running the PL 100 tone. The TM-D700 and TH-D7's can both do this as is. Any APRS mobile packet system can also do this if the TNC is attached to the discriminator prior to the CTCSS squelch circuit. But Voice Alert only works within simplex range. That is why we also need to see the stations other Voice band so we can contact him via the repeater he is currently monitoring. OTHER VOICE SYSTEMS: All specialized local voice assets should also beacon their operating frequency. The three other global internet amateur radio linked systems, IRLP, EchoLink and Winlink also include provisions for beaconing their POSIITON and FREQUENCY data onto the national APRS channel using the FFF.FFFMHz format. This way, mobiles monitoring the national APRS frequency anywhere in the country can be aware of the position and frequency of all amateur radio assets around them. APRS FREQUENCY FORMATS: ----------------------- There are two Frequency formats. The POSITION COMMENT format includes the frequency as FFF.FFFMHz in the free field text of a normal position or object report as noted above. The other is called the OBJECT format because it puts the Frequency in the OBJECT NAME using the format of FFF.FFxyz so that it shows up very clearly on the radio's station list. Of course, an object can also have a frequency in its position comment as well. If both the object name and the comment contain a frequency, then the name is considered the transmit frequency for the object and the frequency in its comment text is its split receive frequency. As noted before, a 10x10x+ format is used for the POSITION COMMENT format for best display on the existing variety of APRS radios. Here are the standard 10-byte formats. Please note that spaces are required where shown. In some cases a "_" may be shown for clarity in this document, but in the actual format, a SPACE should be used: 1st 10-BYTES Frequency Description ---------- ----------------------------------------------------- FFF.FF MHz Freq to nearest 10 KHz FFF.FFFMHz Freq to nearest 1 KHz Examples: 146.52 MHz Enroute Alabama 147.105MHz AARC Radio Club 146.82 MHz T107 AARC Repeater (Tone of 107.2) 146.835MHz C107 R25m AARC (CTCSS of 107.3 and range of 25 mi) 146.805MHz D256 R25k Repeater (DCS code and range of 25 km) 146.40 MHz T067 +100 Repeater (67.8 tone and +1.00 MHz offset) 145.50 MHz t077 Simplex (Tone of 77.X Hz and NARROW band) 2nd 10-BYTES Optional Added fields (with leading space) ---------- ----------------------------------------------------- _Txxx RXXm Optional PL tone and nominal range in miles _Cxxx RXXm Optional CTCSS tone and range in miles _Dxxx RXXk Optional DCS code and nominal range in kilometers _1750 RXXk Optional 1750 tone, range in km, wide modulation _l750 RXXk Optional 1750 tone narrow modulation (lower case L) _Toff RXXk Optional NO-PL, No DCS, no Tone, etc. _Txxx +060 Optional Offset of +600 KHz (up to 9.90 MHz) _Exxm Wxxm East range and West range if different (N,S,E,W) _txxx RXXm Lower case first letter means NARROW modulation _FFF.FFFrx Alternate receiver Frequency if not standard offset _FFF.FFF + Alternate Frequency and standard shift The first 10 bytes must be frequency and "MHz" in mixed case is required. Notice that the second 10 byte fields begin with a SPACE shown above as "_" (9 useable bytes) for better reading of the packet on normal text displays as shown in the examples below. Do not include the "_" but put a SPACE there in your actual packet. Here is the raw packet format for the comments: FFF.FFFMHz comment... one frequency FFF.FF MHz FFF.FFFrx comment... for separate TX and RX FFF.FF MHz T107 R25m comment... for TX, tone and range The 10x10x8 byte format has been defined so that it shows up well on the TH-D7, TM-D700 and Hamhud displays. Examples are as follows: +------------+ +------------+ | >WB4APR-11 | | >WB4APR-11 | | FFF.FF MHz | | FFF.FFFMHz | | FFF.FFF M | | T107 R17m | +------------+ +------------+ OTHER COMBINATIONS: It is important to note that the TEXT field used for this frequency already has several possible options. Normally the comment-TEXT field begins after the SYMBOL byte. But there are already several defined 7 byte Data-Extensions that then push the comment-TEXT field further to the right as shown here. In many applications, an optional delimiter is added to make the packet more readable. THis optional delimiter (usually a " " or "/") is not explicitly called out in the spec, but should be considered in all following parsing of the text field. All of these can be valid use of Data-Extensions and following FREQUENCY info. !DDMM.mmN/DDDMM.MMW$FFF.FFFMHz ... begins after symbol ($) !DDMM.mmN/DDDMM.MMW$CSE/SPD/FFF.FFFMHz ... !DDMM.mmN/DDDMM.MMW$PHGphgd/FFF.FFFMHz ... !DDMM.mmN/DDDMM.MMW$DFSshgd/FFF.FFFMHz ... !DDMM.mmN/DDDMM.MMW$CSE/SPDFFF.FFFMHz ... w/o delimiter !DDMM.mmN/DDDMM.MMW$PHGphgdFFF.FFFMHz ... w/o delimiter Althout the optional delimiter shown here is a "/" it can also be a SPACE character too. FREQUENCY ON GPS TRACKERS: APRS was intended to be a two-way comunications system between human operators. For this reason, transmit-only tracking devices should include their monitoring voice frequency in their packet beacon so that they can be contacted. The format is the same. Simply put the frequency in the position text. If the the tracker does not have that flexibility (such as a NMEA tracker), then put the frequency into the STATUS or BEACON text as follows: BText >FFF.FFFMHz Tnnn etc...... Where the leading ">" makes this packet an APRS STATUS packet and the "etc..." can be any additional free text (or TXXX tone) as needed. On recepit, most APRS programs should combine this info with the station data to make the frequency parseable as needed. RECOMMENDED VOICE REPEATER FREQUENCY OBJECTS: --------------------------------------------- Please see: http://www.aprs.org`/localinfo.html There are two more parseable locations for frequency in the APRS protocol, one is for Object names and the other is the DX Format. OBJECT NAMES: Every New-N Paradigm APRS digipeater is supposed to periodically transmit an OBJECT showing the locally recommended voice repeater frequency for travelers visiting the digi's own coverage area. APRS software should be able to locate these frequencies as well. The format for these frequency object names is as follows: OBJECTNAME ---------- FFF.FFF-z 5KHz repeaters with up to 62 unique (z) ID's FFF.FFFyz 5KHz repeaters with up to 2700 unique (yz) ID's FFF.FF-yz 10kHz repeaters with over 3600 unique (yz) ID's FFF.FFxyz 10kHz using three xyz unique characters... Choose letters to make your repeater frequency unique in all the world so that it can be easily monitored on http://map.findu.com/FFF.FF*. The rest of the OBJECT format contains the TONE and RANGE and any specific information on regular net times and meeting dates. The format for these objects is: ;FFF.FFFxy*111111zDDMM.hhN/DDDMM.hhWrT079 R25m NETxxxxxx MTGxxxx... (15 Jun 08 change. Eliminated the leading space before the T079) Where T079 is a tone of 79.7 Hz (always drop the tenths) Where R25m is a Range of 25 miles (or k for km) Where NETxxxxxx is something like "Net Tu9PM" or "Net Tu730" Where MTGxxxx is something like "Mg3rdTu" and must be 7 bytes Where ... 9 more bytes are possible but won't show on mobiles This exact spacing fits nicely on the 10x10x8 displays of the D7, D700 and HAMHUD and on the 20 byte displays of the VX-8R. TONES and DCS: We force the tone to 3 bytes always for simplicity of display, since all tones are standardized, they do not need the tenths. So T088, C067, T156 and DXXX are all valid entries. Lower case implies NARROW modulation as in t088, c067, t156 etc. OBJECT NAME PERMANANCE: Notice that an object name needs to be unique since there are dozens of 146.94 repeaters in the country, and so these objects choose characters for the optional z, yz and xyz characters above to make them unique. Since these can be upper and lower case and or numbers, this gives 62 unique identifiers for the 5 KHz repeaters and over 3600 for 10 KHz repeaters. If there are still conflicts, then other delimiters such as "_=!^@, etc" can be used in place of the - separator. But always check to see if they get through on FINDU.COM using the link below. To see what freqeuncies are already in use, simply do a wildcard (*) link to FINDU.COM. For example, http://map.findu.com/146.94* will provide a list of all 146.94 repeaters currently showing on APRS and their "xyz" modifiers in use! These objects are transmitted with the pseudo permanent date/time stamp of 111111z. This unique time stamp declares this object to be permanent. This means that it should not be replaced by any other similarly named object unless that object is transmitted by the same originating station. This lets the originator of a permanent object update or move his object, but it then prevents his object from being replaced by anyone else's similar object. DX CLUSTER FORMAT: APRS also decodes the DX CLUSTER format, and this format includes a frequency field too. All APRS software should decode and capture this frequency information also. THE NEXT SECTION IS ALSO FOUND IN: www.aprs.org/echo-irlp-win.txt) EchoLink OBJECT FORMATS: ------------------------ EchoLink object names have the format of EL-123456 so that the node number can be easily seen on the station list of the mobile. This is important, since the mobile user has to have the node number to activate a link. Not the callsign of the node. The rest of the object uses the previous formats above to convey operating frequency and tone, and range. Here is an example OBJECT for EchoLink nodes. ;EL-123456*111111zDDMM.--NEDDDMM.--W0FFF.FFFMHz Tnnn STTS CALL... ............... <== up to a max of 43 total characters The "STTS" is only a four byte field for the current stataus of the node. Maybe "busy", "conf", "off_", "idle" etc. The CALL is the callsign of this node. But we dont get the RANGE info. So maybe: ;EL-123456*111111zDDMM.--NEDDDMM.--W0FFF.FFFMHz Tnnn Rxxm %CALL.. ............... <== up to a max of 43 total characters Where % is a single byte to indicate Status. This will show with all of the information on teh front panel of the APRS mobiles as: +------------+ | EL-123456 | | 438.700MHz | | Tnnn Rxxm | | %CALL.. | +------------+ The only loss is that the -R or -L does not show for most node callsigns unless they are four character calls. Though this is not needed by the mobile operator POSITION DETAILS: In the LAT/LONG fields the TWO hundredths digits are shown entered as SPACE bytes so that the object is transmitted as a one-mile ambiguity object. Replace the two "--" bytes above with SPACES for it to work. The E between LAT/LONG makes APRS display the EchoLink symbol. It is hoped that a single central EchoLink server will generate these objects so that the only thing needed to get them on the air in a local area is to have the local IGate sysop to activate the local object by name for pass-to-RF. ECHOLINK FORMAT USING MIC-E: This format is for the Kenwood D710 radio which reports its position in Mic-E format. This format will appear on the air as: MYCALL>LLLLLL,DIGI:'GGGCSD0E]FFF.FFFMHz Tnnn RXXm Ecolink node= The LLLLLL is the latitude bytes, GGGCSD are the longitude and course speed bytes. The "0E" are the ECHOLINK Symbol bytes. And the "]" byte indicates this is a D700 series Mic-E and the "=" on the end indicates it is the D710 version. The "FFF.FFFMHz Tnnn RXXm" is the frequency and range format. And "Ecolink node" is intentionally misspelled to fit nicely on the display of a D700. IRLP OBJECT FORMATS: -------------------- See the Scrip to add this to your IRLP node: http://irlp.kc6hur.net/irlp_scripts.php IRLP object names are similar and have the format of IRLP-1234 or IRLP12345 if they ever go to 5 digits. This format is so that the node number can be easily seen on the station list of the mobile. The rest of the object uses the previous formats above to convey operating frequency and tone, and range. Here is an example OBJECT for IRLP: ;IRLP-1234*111111zDDMM.--NIDDDMM.--W0FFF.FFFMHz Tnnn STTS CALL... ............... <== up to a max of 43 total characters In the LAT/LONG fields the TWO hundredths digits are shown entered as SPACE bytes so that the object is transmitte as a one-mile ambiguity object. Replace the two "--" bytes above with SPACES for it to work. The I between LAT/LONG makes APRS display the IRLP symbol. It is hoped that a central server will be written for these objects as well so that they can be consistently generated into the APRS-IS and then only gated back to RF locally. The STATUS (STTS) can be something like these: (Idle, off_, busy, etc). For more info, contact Mark Herson n2mh@n2mh.net WiRES OBJECT FORMATS: ------------------------ Yaesu WiRES nodes should also appear on the APRS channel. For example for an OBJECT NAME : WIR-1101D the format would be: Example: WiRES Node Number = "1101D" (Lat:3348.43N/Lon:11802.32W) ;WIR-1101D*111111z3348.43NW11802.32W0430.900MHz D023 R20m STTS... ............... <== up to a max of 43 total characters If an FTM-350 Radio is used as the WiRES node, then it will identify using the Mic-E format and should use this format: MYCALL>LLLLLL,DIGI:'GGGCSD0W`FFF.FFFMHz Tnnn RXXm WiRES node _" WINLINK OBJECT FORMATS: ----------------------- WinLINK Telpac gateway object names have the format of W?-CALLSIGN (where W? can be WL or W1, W2,... W9 for multiple stations) so that the node callsign can be easily seen on the station list of the mobile. The rest of the object uses the previous formats above to convey operating frequency and range. The baud rate, "bbbb" for packet is inserted in place of the TONE, Txxx for voice. Here is an example OBJECT for injection into the APRS-IS: ;WL-AB9XYZ*111111zDDMM.--NWDDDMM.--WaFFF.FFFMHz 1200 RXXm comment ............... <== up to a max of 43 total characters In the LAT/LONG fields the TWO hundredths digits are shown entered as SPACE bytes so that the object is transmitte as a one-mile ambiguity object. Replace the two "--" bytes above with SPACES for it to work. The W between LAT/LONG and "a" symbol makes APRS display the WinLink symbol. MICROWAVES: Of course FFF.FFFMHz only works to 999.999 MHz, and so we have defined some letter designations above that. There are two methods. One, is to simply use GHz as in XXX.XXXGHz. But this is limited to wideband modes to the nearest MHz. Example is __1.296GHz for 1296 MHz. But to retain one KHz resolution, we use this table of alphabetical extensions: A96.000MHz would be 1296 MHz B20.000MHz would be 2320 MHz C01.000MHz would be 2401 MHz D01.000MHz would be 3401 MHz E51.000MHz would be 5651 MHz F60.000MHz would be 5760 MHz G30.000MHz would be 5830 MHz H01.000MHz would be 10,101 MHz I01.000MHz would be 10,201 MHz J68.000MHz would be 10,368 MHz K01.000MHz would be 10,401 MHz L01.000MHz would be 10,501 MHz M48.000MHz would be 24,048 MHz N01.000MHz would be 24,101 MHz O01.000MHz would be 24,201 MHz APRS FREQUENCY-IN-MESSAGE FORMATS: A variety of formats have been proposed, but until someone is ready to implement either the auto- QSY on receipt of a message, or to transmit such a message, it is premature to nail down an exact format. But something like: QSY FFF.FFFMHz! ... Auto QSY now QSY FFF.FFFMHz? ... Auto QSY unless user hits NO QSY FFF.FFFMHz. ... QSY if user manually hits TUNE CONCLUSION: Examples of frequency use in APRS are obvious: 1) Advertising the voice frequency you are monitoring 2) Voice repeater and other local frequency Objects 3) Mobile GPS map display of surrounding frequency assets 4) IRLP and EchoLink nodes 5) WinLINK Packet nodes 6) EOC operations 7) Long distance travelers 8) ATV repeaters and links, etc... Since the object of APRS is to facilitate local communications and situational awareness of all surrounding ham radio assets, everyone is encouraged to include their operating frequency in their position packets to make their availability known. de WB4APR Bob Bruninga