The official ScanOnt FAQ V1.1
Last updated May 3rd 2005


Compiled by:
Bill Blyleven
Bryan Passifiume

Contributors:
Trevor Something, Bob Heuman, Terry Green, Steve Jones, Simon Martin, Dave Archer, Andrew Porrett, Mike Iszak



PREFACE:

This document was created in assist the users of the ScanOnt yahoogroup in answering frequently asked questions, not only to help the users and scanner users in general, but to keep the same questions from being asked on the list constantly.

This has been designed as a constantly evolving document. If you have any additions, suggestions or corrections, please let us know. Scanont is Ontario's first and best Scanner resource and mailing list, and we want to make sure that it has the best FAQ available to it's members. Many people try to duplicate Scanont, but none come close.

Here's what you won't find in this FAQ:


If you have any additions or corrections to this FAQ, please send them to [email protected].

Thanks for reading, and keep on scanning!!






Contents:

SECTION 1: THE BASICS

1.1 .......... What is a scanner?
1.2 ..........What is a repeater?
1.3 ..........What is Simplex?
1.4 ..........What is Talkaround?
1.5 .......... Legal questions regarding scanning
1.6 .......... Can I stream my scanner on the internet?
1.7 ........... Where can I get information on my city's radio frequencies?

SECTION 2: TRUNKING

2.1 ..........What is Trunking?
2.2 ...........What is a Talkgroup?
2.3 ..........Motorola Trunking
2.3.1 .....................Type I and Type II systems
2.3.2 .....................Status Bits
2.3.3 .....................Patching
2.3.4 ......................MSEL
2.3.5.......................SmartZone
2.4 ..........iDen
2.5 ..........EDACS
2.6 ..........LTR
2.7 ..........MPT-1327
2.8 ..........Control Channels
2.9 ..........I-Calls
2.10 ..........What is a tower?
2.11.............Control Channel trunking

SECTION 3: DIGITAL

3.1 ..........What is Digital?
3.2 .......... Do I need a digital scanner?
3.3 .......... Do I need a license to buy and use a digital scanner?
3.4 ..........What scanners can handle digital?
3.5 ..........What is PROVOICE?
3.6............What is AEGIS

SECTION 4: FLEETNET

4.1 .......... What is Fleetnet?
4.2 .......... Who is on Fleetnet?
4.3 .......... How do I program my scanner to receive Fleetnet?
4.4 .......... What scanners can handle digital?
4.5 .......... What scanners can listen to the analog Fleetnet talkgroups?

SECTION 5: MISCELLANEOUS INFO


5.1 ..........Encryption
5.2 ..........Signalling Formats
5.2.1.........QuickCall
5.2.2.........MDC-1200
5.2.3.........GE-STAR
5.2.4.........DTMF
5.2.5.........MODAT
5.3............CTCSS
5.4............ Data Slicers
5.5.............Trunker/ETrunk
5.6.............Popular Acronyms


APPENDIX

A1.............CNI Quick response codes
A2.............Common 10 codes
A3..............NATO Phonetic Alphabet
A4..............Popular Acronyms





SECTION 1 - THE BASICS

1.1 - What is a Scanner?

A scanner is a radio receiver capable of receiving signals outside of the regular AM and FM radio band, allow these signals to be programmed to a bank of memory locations, and to rapidly 'scan' them, stopping on channels with open carriers. The ability to 'scan' is a defining characteristic of a scanner. Some shortwave and amateur radios are able to receive frequencies that scanners are able to pick up, but they would not be considered "scanners".

Modern Scanners can be grouped into three main categories:

Of these, scanners come in three main configurations:

Also note that many modern scanners can be programmed and/or controlled by a computer.


1.2 - What is a Repeater?

A repeater is a device that extends the range of mobile and portable radios. A repeater consists of a dedicated high-power radio unit that receives transmissions on its input frequency and simultaneously re-transmits them on its output frequency. Most repeaters have a set, band-dependant channel spacing (all repeaters on a particular band will have their input and output frequencies separated by the same amount, known as a REPEATER OFFSET). Ham radio makes use of repeaters quite frequently, as do most commercial radio users. For very obvious reasons, scanner users need only worry about monitoring a repeater’s output or tx frequency.


1.3 - What is Simplex?

Simplex is the basic operation of a two way radio – any number of people talking on radios that operate on the same frequency for transmit and receive. Radios set up for duplex or repeater operation have different frequencies programmed for it’s transmit and receive, transmitting to the repeater’s input, and receiving on the repeater’s output. Many police and fire agencies with trunked radio systems have simplex channels for emergency failsafe, surveillance operations or special events.



1.4 - What is Talkaround?

Used often in ham radio or public safety systems, most two-way radios have a TALKAROUND function. Talkaround is the function of transmitting and receiving only on a repeater’s output frequency, to avoid conversations from being transmitted over the repeater. This is used either for non-important conversations with nearby units, or for communicating with a nearby party without needlessly tying up the repeater. As talkaround conversations are not sent through a repeater, you must be rather close to listen to the conversation.

1.5 - Legal concerns regarding scanning

Coming soon



1.6 - Legal issues regarding streaming your scanner on the internet

Coming Soon



1.7 - Where can I get information on my city's radio systems?

The absolute best resource is http://www.radioreference.com. You need to sign up for an account to access the radio frequency and trunked radio listings, but it will allow you access to the entire database and the often entertaining RR forums. Access is free.

Radio Reference used to be www.trunkedradio.net.



SECTION 2 - TRUNKING


2.1 - What is Trunking?

Trunking is a computerized method of allowing a large number of people/agencies to use a relatively small amount of actual frequencies. This is accomplished by a computer that controls all of the radios on the system, informing them of what frequency to operate on. Radios are programmed with specific talkgroups (channels) that the user can either listen to or talk on. The frequency for each talkgroup changes every time someone keys their radio to speak. The term “trunking” comes from the telephone industry, as the method of selecting the next available ‘circuit’ between exchanges is very similar to what happens in a ‘trunked’ radio system. A TrunkTracking scanner will listen to the system's control channel and follow frequency changes for whatever talkgroup you are listening to.A conventional scanner can monitor a trunked radio system, but it would not be able to track frequency changes. Conversations would make no sense, as you would be be only hearing parts of conversations across the entire system.


2.2 - What is a Talkgroup?

A talkgroup is analogous to a radio channel in a trunked radio system. The trunk controller for the system will, when a radio’s PTT is pressed, assign a free frequency for the radio to transmit on and order all radios on that talkgroup to switch to that frequency. Frequencies assigned will change every time someone talks into their radio. A TrunkTracking scanner will listen to the system's control channel and follow frequency changes for whatever talkgroup you are listening to.


2.3 - Motorola Trunking

Motorola trunking is the most popular trunking system in North America. Motorola trunking systems can be found in the VHF, UHF , 800 and 900 MHz bands (systems in the 700 Mhz band are planned for the future). There are two main types of Motorola trunked radio systems: Type I and Type II. Type I is archaic and is rarely used. Motorola trunked radio systems support both analog and digital voice transmissions.

2.3.1 - Type I and Type II systems

Type I and Type II transmissions both use 16 bits to represent a talkgroup. These bits are sent out with every transmission and are interpreted by your scanner. A Type I system divides up those 16 bits into blocks, fleets, subfleets, and users. Talkgroups in Type I systems are usually displayed as FFF-SS, where FFF is a Fleet ID and SS is a subfleet ID. The trick with Type I systems is determining exactly how a particular system divides up those 16 bits. That information is represented by what’s called a “fleet map”. A Type II system divides the 16 bits differently than a Type I system. The 16 bits in a Type II system are split into 12 bits of talkgroup identifier and 4 status bits. The status bits identify special situations and are usually all zeroes.

2.3.2 - Status Bits

As described above, status bits are the four bits transmitted after the talkgroup identifier. Typically, we are only concerned with the last three bits, as the first bit determines encryption. Most trunk tracking scanners after the Uniden BC-235 have a status bit function, which strips the status bits from the TG-ID. Scanner users should typically disregard status bits, as they are of no use to the user and can be confusing.

Status bits, on a trunking scanner, typically display as the talkgroup number + a certain number. For example, talkgroup 112 with a radio in emergency will display on your scanner’s display as 114. The STATUS BIT function on your scanner (if so equipped) will strip the status bits from the talkgroup, so you’ll see 112 no matter what status bits are present

A list of status bits are:

ID+0 Normal Talkgroup
ID+1 All call (dispatcher talking to all talkgroups)
ID+2 Emergency
ID+3 Talkgroup patch initiated
ID+4 Talkgroup patch + Emergency
ID+5 MSEL + Emergency
ID+6 Not in use
ID+7 MSEL
ID+8 DES Encryption enabled
ID+9 All call + DES
ID+10 Emergency + DES
ID+11 Talkgroup patch + DES
ID+12 Talkgroup patch + Emergency + DES
ID+13 MSEL + Emergency + DES
ID+14 Not in use
ID+15 MSEL + DES
2.3.3 - Patching

The dispatcher is able to connect (patch) two or more talkgroups together, so all patched talkgroups function as one (the dispatcher talks to both talkgroups, and all users on all talkgroups can speak to each other).

Usually low-traffic talkgroups are patched together during off-peak hours (Peel Regional Police 21 Division and Pearson Airport Division talkgroups are patched together overnight when the airport talkgroup is less busy, with a single dispatcher operating both). Sometimes talkgroups are patched together on a permanent basis. Toronto Police have several divisional talkgroups patched together, with a single dispatcher operating both. (22/23, 11/12, 51/53, 32/33, 51/53, 54/55, 13/Highway Patrol divisions are permanently patched). Dispatchers can also patch in non-trunked channels, such as the OFM channel, dispatch paging frequencies, I-TAC channels, mutual aid frequencies, etc. Helicopters are often connected to trunked radio systems via a patched simplex frequency, as transmissions from great heights are not authorized on trunked repeater inputs. Transmitting from the height of an operating helicopter enters the risk of interfering with distant systems that might be operating on the same frequencies. Mike Iszak writes: "The York Regional Police helicopter doesn't use a simplex channel, it
uses the trunked system, just the same as any other car.  This is also what happens with the Durham Police, they just have an M100 iDEN radio in the chopper and away they go."

2.3.4 - MSEL

A dispatcher is able to MultiSelect several talkgroups together, which allows him/her to speak to several talkgroups at the same time. The difference between an MSEL and a Patch is, unlike a patched talkgroup, MSELed talkgroups remain separate and users are not able to communicate with other talkgroups. MSELs are sometimes used by the Peel Police when reading announcements/bulletins/10-70’s. Fire dispatchers use them frequently as well to dispatch calls. Toronto Fire dispatchers MSEL the relevant zone’s operations talkgroup, as well as the FIRE DISPATCH talkgroup.

2.3.5 - SmartZone

SmartZone is a type of wide-area Motorola Type II trunked radio network, employing several towers (acting as separate trunked radio systems) connected by a controller. All radios within the network can ‘roam’ across any tower in the network, similar to a cellular phone network. Any radio outside of their ‘home zone’ will cause whatever talkgroup it is monitoring to be simulcast on whatever tower it is closest to (A London OPP cruiser in Toronto will cause the London OPP dispatch to appear on the Toronto tower – but only if it’s radio is tuned to OPP London Dispatch). Fleetnet and the Toronto Trunked Radio system are SmartZone systems. In order to monitor SmartZone radio systems, you must program in each tower of the system into your scanner as a separate radio system. On some newer scanners such as the Uniden BC246T, you can use the Control Channel trunking feature to scan all towers without having to program each tower. Simon Martin writes: "On newer scanners such as my BC246T, with CC only scanning, I am able to enter ALL the CCs for every tower and scan a system, and it works fine. I have all my Smartzone systems, like Fleetnet and Toronto PSS, programmed this way.The scanner, if it finds nothing on one CC, moves to the next."

In response to Simon Martin's suggestion, Andrew Porret points out: "One loses the ability to select which site the scanner monitors; try monitoring 4 District reliably when your scanner has decided to use the north zone site."

Mike Iszak adds: "a trick for the scanners that don't do CC only mode...take all the frequencies used on fleetnet and enter them in one bank, and if a new voice frequency gets added, you should be all set.  I have my 796 set up this way, and every new frequency that's been added in the last 4 or 5 months, I've already got programmed in there.  Leave the first two channels blank, and use that to program in the control channels of the tower you want to hear.  This way, it'll scan those two frequencies before it looks on the other channels, ensuring you'll lock onto the tower you want instead of another one that might be using one of the voice channels on another site"

2.4 - What is iDEN?

iDEN is a trunked, digital radio system, most commonly found as the PTT/Direct Connect service of the Telus Mike and Nextel systems. Used mainly by businesses as a hassle-free and low-cost radio dispatch solution, it is used by a handful of police services as their primary radio system (Durham Regional Police, for example use radios on the Telus Mike system). iDEN cannot be monitored with a scanner. A large 900 MHz iDEN system is used by non-public safety workers at Pearson Airport.


2.5 - What is EDACS?
EDACS (Enhanced Digital Access Communications System) is a type of trunking system developed by GE/Ericson/Tyco-MA/com respectively. Characteristics of EDACS are:

The Toronto EMS radio system, as well as Halton Regional Police, use 800 Mhz EDACS systems.


2.6 - What is LTR trunking?

Logic Trunked Radio – Developed by EF Johnson/Transcrypt, it’s a somewhat popular trunking format that doesn’t rely on a specific control channel – all channels are used for voice and data transmissions. LTR is not APCO compliant due to lack of an emergency/man down function and no RID (Radio ID) feature (no way to uniquely identify an individual radio), and therefore is not normally used for public safety agencies (there are some exceptions, though).


2.7 - What is MPT-1327/MPT-1343

A trunking system used primarily in Europe (MPT was developed by the British Ministry of Post and Telecommunications). It is a popular, open protocol trunked radio system that supports analog voice communications. MPT 1327/1343 does not have a separate control channel. The TTC uses MPT-1327 for their subway radio network. MPT-1327/1343 systems cannot be tracked with any known scanner model. MPT-1327/1343 systems can be tracked using the TrunkSniffer or FTrunk programs.


2.8 - What is a Control Channel?

A Control channel is a digital stream of data that all radios on a trunked radio system monitor. Control channels inform radios what frequencies to use for certain talkgroups, data transmissions, status indications, emergency notifications, etc.

For sound samples of what control channels of specific radio systems sound like:

EDACS 9600 baud: http://www.kb9ukd.com/digital/edacs96.wav
Motorola Type II: http://www.kb9ukd.com/digital/motorola2.wav
MPT1327: http://www.kb9ukd.com/digital/mpt_1327.wav


2.9 - What are I-Calls?

An I-call is a conversation that takes place between two specific radios outside of their specific talk group. Many scanners do not monitor/track I-calls.


2.10 - What is a Tower?

A tower is a structure for holding the antennas for that specific trunking site. It could be the top of a building or an actual steel frame tower in the middle of nowhere. It is also a term for a separate ‘system’ or node of a Smartzone radio system (Fleetnet, Toronto Trunk, etc.) In order to monitor a SmartZone radio system, you need to enter in each ‘tower’ into your scanner as if it were a separate Type II radio system. The term “tower” is also used in railway radio. “Keying the tower” is a term used by train and MoW crews to page the dispatcher.


2.11 - What is Control Channel trunking?

Control Channel trunking is when only the control channel of the trunking system is used to follow conversations on the system. Most scanners available have this feature. Base offset and spacing is needed for UHF and VHF systems as they do not follow a preset plan for channels like 800 and 900 MHz systems.





SECTION 3 - DIGITAL

3.1 - What is Digital?

Digital radio is increasingly becoming popular among public safety agencies. Voice radio is modulated into a digital radio signal and is transmitted over the air.

Radio spectrum is a natural resource that has become quite clogged as it's so popular. As such, narrowband requirements have been introduced into the commercial spectrum to make more room for others users. Digital radio allows more efficient use of bandwidth of the spectrum. Not to mention, digital radio sounds excellent to the end-users and uses very little bandwidth in
comparison to analog to do so.

It is comprised of 2 parts:

The standard codec for interoperabliity is Project 25 digital, as determined by APCO (Association of Public Safety Communications Officials). The use of P25 digital ensures interoperability across radio brands. A P25 radio from Vertex Standard will be able to communicate with a P25 radio from Motorola.

Motorola currently has two types of digital radio formats: VSELP and IMBE. VSELP is a first generation codec, and is seldom used these days (Peel Regional Police use VSELP for their “encrypted” channels). IMBE is P25 compliant, and is the format that the OPP use on Fleetnet. VSELP is not P25 compliant, and cannot be monitored with a digital scanner.

DIGITAL can be a used on either a single channel (i.e. Niagara Regional Police) or in a trunked system (i.e OPP in southern Ontario). Digital is not Encryption (see below); it is a type of modulation.

All digital scanners are P25 compliant, and can only decode P25 digital transmissions.

3.2 - Do I need a Digital scanner?

It depends on what you want to listen to. If you want to listen to the OPP, you will need one. The OPP currently operate on digital talkgroups on Fleetnet. There are also other local agencies that operate digital radio systems (Barrie Fire, for example). Check http://www.radioreference.com for information on your local radio system. Unless you just have to have the latest toy or gadget, there’s no real reason to spend the money for a digital scanner unless you need one.

3.3 - Do I need a license to buy and/or use a digital scanner?

No you do not. A circular was released by Industry Canada close to seven years ago claiming that a “Digital Scanner License” was required to use or purchase a digital scanner, and further noted that they would only be issued to Emergency Workers and Amateur Radio operators. To this date there has been no official mandate from IC regarding the need to obtain a license. As well, no applicaiton form exists for such a license, as well as no law or mandate requiring any special certification to purchase a digital scanner. A certain north Toronto amateur radio store with a reputation for terrible customer service has, on occasion, refused sale of digital scanners to those without a ham radio license. This is their own policy as opposed to a mandate from IC. This particular store has a bad habit of treating non-amateur radio scanner customers as second-class citizens, so it's not all that surprising such a policy exists. Purchasing them in the US is a cheaper alternative, and there are no regulations forbidding the importation of such devices into Canada. This subject is a point of much contention on Scanont.

in response to this entry, Andrew Porrett writes: "IC *did* hassle many digital scanner retailers in the GTA back when the first digital Uniden scanner (BC250) was introduced.  This action was triggered by complaints from the OPP.  Radioworld did not make up this policy - they're just covering their ass.  However, if other retailers have figured out how to make peace with IC (e.g. sell digital scanners to non-hams), RW should pull its head out of its ass and get with the program."


3.4 - What scanners can "go digital"?

BC250 Handheld, 1000ch, 10 banks, follows OPP with additional card. $275U to $375U card is $250U
BC296 Handheld, 1000ch, 10 banks, follows OPP with built in card $519U $800C
BC785 Base/DIN, 1000ch, 10 banks, follows OPP with additional card $299U card is $250U
BC796 Base/DIN, 1000ch, 10 banks, follows OPP with built in card $519U $800C
Pro 96 Handheld, 500ch, 10 banks. $375U to $475U used $499U new RadioShack USA
Pro 2096 DIN, 500ch, 10 banks. $499U new RadioShack USA


3.5 - What is PROVOICE?

MA/COM PROVOICE is the current digital format that is pushed by MA/COM. It's prominently used on EDACS systems, but can be used on conventional simplex as well. The format is quite similar to IMBE, but differs with some features such as error correction. Despite rumors, MA/COM has stated numerous time it would never license their proprietary codec to scanner vendors. This means, there most likely will not be a scanner introduced that allows you monitor such transmissions. Mike Iszak writes: "ProVoice is aparantly P25 compliant, but doesn't use the Common Air Interface (CAI), so you cannot monitor it with a digital scanner."

3.6 - What is AEGIS

This digital format was the second generation digital voice developed by GE/Ericsson. It's since been replaced by ProVoice. AEGIS transmissions cannot be monitored with a scanner, however, the good news is - few agencies still use AEGIS. AEGIS is not P25 compliant.



SECTION 4 - FLEETNET

4.1 - What is Fleetnet?

Bell Fleetnet/GMCP/BMR refers to the province-wide Government of Ontario radio system that will eventually span about 80%
of the province. Currently (as of spring 2005) all of southern Ontario and most of eastern Ontario is using this systems. Fleetnet is a Motorola SmartZone Type II wide-area mixed-mode trunked radio system. Fleetnet is made up of two ‘zones’ – Zone 1 encompasses all of Southwestern Ontario and consists of over 40 towers, and Zone 2 consists of all of Eastern Ontario. Fleetnet is operated by Bell Mobility Radio (a separate division of Bell Mobility cellular – their networks are NOT related)

4.2 - Who is on Fleetnet?

The primary user of Fleetnet is the Ontario Provincial Police, who operate on unencrypted IMBE digital talkgroups (you need a digital scanner to monitor them). Current and/or future users of Fleetnet consist of:

4.3 - How do I program my scanner for Fleetnet?

Visit Mike Oxlong's excellent tutorial on programming the BC-780, BC-785, BC-250D, BC-296D on RadioReference.com at: http://www.radioreference.com/modules.php?name=Forums&file=viewtopic&t=8179


4.4 - What scanners can do digital?

BC250: Handheld, 1000ch, 10 banks, follows OPP with additional card. $275U to $375U card is $250U
BC296: Handheld, 1000ch, 10 banks, follows OPP with built in card $519U $800C
BC785: Base/DIN, 1000ch, 10 banks, follows OPP with additional card $299U card is $250U
BC796: Base/DIN, 1000ch, 10 banks, follows OPP with built in card $519U $800C
Pro 96: Handheld, 500ch, 10 banks. $375U to $475U used $499U new RadioShack USA
Pro 2096: DIN, 500ch, 10 banks. $499U new RadioShack USA


4.5 - What scanners can do the analog Fleetnet talkgroups?

Pro 92 + Pro2067: Only used
Pro 94: New on closeout RadioShack USA spring 2005
BC245: Used, some available new but overpriced.
BC246T: New state of the art
Pro 97: New but has limitations on Fleetnet
Pro 2051: New
BCT 8: New
Pro 2052: New on closeout RadioShack USA spring 2005



SECTION 5 - MISCELLANEOUS


5.1 - Encryption

Encrypted transmissions, unfortunately, are becoming more popular as privacy and security concerns are entering the forefront. Encryption can range from simple voice inversion (making voices on the system sound like Donald Duck) to more sophisticated encryption algorithms employing encryption keys.

Digital encryption schemes have been around for many years. Motorola’s Securenet system consists of five unique (and non-compatible) protocols: DVP, DVP-XL, DES, DES-XL and DVI-XL.

DVP/DVP-XL: Digital Voice Privacy was developed in the 1970’s by Motorola as a proprietary encryption protocol, meant mainly for non-sensitive non-classified users who wanted to eliminate eavesdropping. DVP-XL was developed to address concerns of decreased range when encryption was in use. 2.36x1021 encryption keys are possible with DVP.

DES/DES-XL: Data Encryption Standard was developed in the mid 1970’s a strictly government-only encryption protocol, used as a common standard among US Government agencies for sensitive (but not classified) communications. DES uses 7.2x 1016 possible encryption key combinations. A P25 compliant digital encoding standard is DES-OFB.

DVI-XL: This format is an export-version of DES.

For top secret communications (such as Secret Service operations), an encryption key known as FASCINATOR is used. Details of the FASCINATOR algorithm is highly classified.

Monitoring of voice inversion is easy with the correct equipment. Monitoring of digital encryption is impossible, as it not only requires a radio with the proper encryption module, but it needs to be loaded with the proper key.


5.2 - Signalling Formats

5.2.1 - QuickCall

Motorola QuickCall/QuickCall II is a tone-based paging system used for paging out fire/EMS calls and for station announce. Halton/Peel/York EMS, for example, use a QuickCall II based system to page out calls to ambulance stations. QuickCall usually consists of a series of tones (to activate a station’s speaker), immediately followed by the dispatch. People who remember the TV show Emergency! are familiar with Motorola QuickCall. Mike Iszak writes: "EMS does not use Quick Call II for their station paging.  They use the GE format called Type 99.  It's basically the same thing, and is compatible with Motorola pagers, but it's not technically QCII."

5.2.2 - MDC-1200

MDC-1200 is a proprietary Motorola Data transmission protocol used quite frequently in Ontario. It is most commonly used as a PTT-ID function (A brief data burst transmitted when a radio user presses on his PTT, the familiar SQUAAWWK! usually before or after the user speaks). MDC-1200 is also used by Mississauga Fire’s station paging frequency to turn on station paging dispatch speakers. A sample of MDC-1200 can be found here: http://www.kb9ukd.com/digital/mdc1200.wav

5.2.3 - GE-STAR

Similar to MDC-1200, GE-STAR is a proprietary GE-Ericsson data transmission protocol. It is commonly used by GO Transit on their buses, as well as several police forces. A sample of GE-STAR can be found here: http://www.kb9ukd.com/digital/ge-star.wav

5.2.4 - DTMF

Dual Tone Multi-Frequency. It is used as a transmission medium for short-length telemetry or PTT-ID, commonly used on Taxi company's radio systems. DTMF is also used for repeater control or system access, most commonly used in the railroads to page the dispatcher/RTC. Anyone who has used a telephone in the past 30 years knows what DTMF sounds like.

5.2.5 - MODAT

MODAT is an archaic signalling format seldom used these days. It was used as a simple PTT-ID system, transmitting a series of numbers based on the pitch of the tones. Very few, if any, agenices use MODAT, except for a select group of area HAMS who are under the false impression the "boobeldabeep!" sound it makes is 'cool'. A sample can be found here: http://www.kb9ukd.com/digital/modat.wav



5.3 - CTCSS

Continuous Tone Coded Squelch System (also known as PL Tones, Tone Squelch or Privacy tones). CTCSS is a sub-audible tone that is transmitted with voice transmissions. Only radios set with the correct tone can receive signals transmitted with CTCSS. CTCSS is used to eliminate unwanted traffic or noise from the channel. CTCSS tones are also used to limit repeater access, so only authorized radios can access a repeater. This is used so repeaters don’t end up retransmitting noise (intermod) or spurious signals.

5.4 - What is a Data Slicer?

A slicer is a simple electronic circuit that can take base audio from a scanner (usually through it’s discriminator tap) and modulates it into a signal a computer can interpret and use through it’s serial port. Programs like Trunker use Data Slicers to monitor a trunked radio system’s control channel. Programs can also decode POCSAG and FLEX pager signals received via a data slicer and display it’s data.

5.5 - What is “TRUNKER” and ETrunk?

TRUNKER is a DOS based program that can log data from a Motorola trunking system. Trunker connects to a scanner locked on a system's control channel interfaced with a data slicer. It is also possible to control a second (computer controllable) scanner to follow voice traffic on the system, allowing one to monitor a trunked radio system without the need of a TrunkTracking scanner.

ETRUNK is similar to TRUNKER, but works with EDACS systems.

5.6 - What is refarming?

Due to interference caused by cellular phone companies operating alongside public safety organizations in the 800 Mhz and 900 Mhz band, certain users will have to relocate. This only affects users in the USA. This is a concern because some scanners on the market cannot scan the new frequencies when in Trunk mode. This is also called REBANDING.

5.7 Can I listen to cell phones on my scanner?

It depends on the scanner. US law forbids sale or use of any scanner that can receive analog cell phone conversations. In Canada there is no such law, but most of the scanners on the market are manufactured for the US market. Some manufacturers have both US and EXPORT versions of their scanners, which are able to receive the 800 MHz analog cell phone band. However, the increasing popularity of digital cell phones have made older analog cell phones all but obsolete. There's very little cell phone activity to listen to these days, and the newer digital cell phones cannot be monitored with a scanner.





APPENDIX

A1 - What are the CNI quick response codes?

 CNI codes are a summary of a person's history with police.  A person could have no outstanding warrants etc but the CNI will "flag" the office of the subjest's history and potential and so the officer can be better preparared/informed.
 
Flag Alpha: Person considered armed and dangerous
Flag Echo: Person escaped custody
Flag Mike: Person considered missing
Flag Sierra: Person missing
Flag Victor: Person violent

A2 - What are some common 10-codes?

"Not all police agaencies in Ontario share the same code system.  The OPP uses a common one that many American agencies use.  Othetr regional agencies uses codes that do not correspond with others. I used to be a dispatcher for the OPP for 12 years (1990-2002), and we ran into this when we talked to other dispatchers or officers on OPC common. Actually the OPC policy was to use common language on OPC common to prevent confusion.  You'd think it would be the same but each agency does its own thing" (submission by Dave Archer)

10-1 Receiving poorly
10-2 Receiving well
10-3 Stop transmitting on this channel until further notice
10-4 I rather enjoy Hamsexy.com
10-5 Relay message
10-6 Busy - stand by
10-7 Out of service
10-8 In service
10-9 Repeat message
10-10 Switch to common channel
10-11 Dispatched too rapidly
10-12 Officials present
10-13 Existing conditions
10-14 Escort
10-15 Message delivered
10-16 Pick up prisoner
10-17 Go to ______
10-18 Complete assignment
10-19 Return to station
10-20 What is your location?
10-21 Call by telephone
10-22 Disregard
10-23 Stand by
10-24 Assignment completed
10-25 Contact
10-26 Detain subject
10-27 Driver's license check
10-28 Vehicle registration check
10-29 Wants and warrant check
10-30 Improper use of radio
10-31 Pick up
10-32 Units needed
10-33 Emergency (either a VERBAL 10-33, or emergency button pressed on radio)
10-34 Time check
10-35 Major alert
10-36 Correct time
10-37 Drunk
10-38 Investigation alert
10-40 Advise if available
10-42 Not according to regulations
10-45 Fatality
10-46 Holding suspect
10-47 Ambulance needed
10-50 Subject negative
10-51 Tow truck needed
10-60 Subject negative
10-61 Subject has record - not wanted
10-62 Subject possibly wanted
10-63 Subject wanted
10-64 Proceed with caution
10-65 Assist with 10-64
10-66 Subject in observation category
10-67 Subject in parolee category
10-68 Subject in charged category
10-69 Can you respond?
10-70 Subject in prohibition category
10-70 Division-wide announcement (Peel Regional Police)
10-71 Subject in refused category
10-72 Subject in prohibited category
10-73 1. Subject in elopee category
2. Back up officer on a call (Peel Regional Police)
10-74 Subject missing
10-75 Subject in pointer category
10-78 Officer needs assistance
10-90 Burglar Alarm
10-92 Person in custody
10-93 Road block
10-100 Bomb threat
10-200 The Police (Used by Ambulance, also shortened to "200")
10-2000 Police needed urgently (Used by Ambulance)


A3 - NATO Phonetic Alphabet

Alpha
Bravo
Charlie
Delta
Echo
Foxtrot
Golf
Hotel
India
Juliet
Kilo
Lima
Mike
November
Oscar
Papa
Quebec
Romeo
Sierra
Tango
Uniform
Victor
Whiskey
X-Ray
Yankee
Zulu


A4 - Popular Acronyms

-A-
APCO - Association of Public safety Communications Officers
AMBE - Advanced Multi-Band Excitation, a digital voice codec
ALS - Advanced Life Support, an advanced paramedic with special training
AVL - Automatic Vehicle Locator, GPS-based vehicle location system. Toronto EMS use AVL to track their vehicles

-B-
BFEM - Brampton Fire & Emergency Services
BLS - Basic Life Support, a paramedic

-C-
CAD - Computer Aided Dispatch
CB - Citizen's Band, a AM 27 MHz radio service
CTCSS - Continuous Tone Controlled/Coded Squelch System
CACC - Central Ambulance Communications Centre, dispatch centre for ambulance services
CNI - Crimial Name Index, a search method of CPIC that returns only the existence of someone's criminal record.
CPIC - Canadian Police Information Centre, an RCMP-run computer network of crimes and criminals (link)
CIB - Criminal Investigation Bureau. PRP-based agency
CRC - Collision Reporting Centre
COR - Community Oriented Response Unit (Toronto Police)
CTAS - Canadian Triage and Acuity Scale
CAI - Common Air Interface

-D-
DES - Digital Encryption Standard, a voice radio encryption protocol
DVP - Digital Voice Privacy, a voice radio encryption protocol

-E-
EDACS - Enhanced Digital Access Communications System
EDP - Emotionally Disturbed Person. see: MHA
ETF - Emergency Task Force (Toronto Police)
ERU - Emergency Response Unit, Peel Police patrol officers that respond to priority calls. Use RESPONSE callsign on the radio

-F-
FRS - Family Radio Service, a low power UHF license free radio service
FAC - Firearms Aquisition Certificate
FIS - Toronto Police forensics unit

-G-
GMRS - General Mobile Radio Service, a low power UHF license free radio service
GPS - Global Positioning System
GOA - Gone on Arrival

-H-
HBD - Has Been Drinking, term for someone obviously intoxicated.
HBD - Hot Box Detector, common wayside railway devices used to detect overheated wheel bearings
HRPD - Halton Regional Police Department

-I-
IMBE - Improved Multi-Band Excitation, P25 standard digital speech modulation and compression codec
IDENT - Forensics unit

-L-
LOC - Level of Consciousness

-M-
MVC - Motor Vehicle Collision
MOH - Ministry of Health
MNR - Ministry of Natural Resources
MFD - Mississauga Fire Department
MDT - Mobile Data Terminal, in-car computer terminal used by police and other agencies
MWS - Mobile Work Station, in-car laptops used by Toronto Police
MHA - Mental Health Act... used as a verb to describe someone who might fall under the Mental Health Act. See: EDP

-N-
NCIC - National Crime Information Centre

-O-
OPP - Ontario Provincial Police

-P-
PL - Private Line tone, a proprietary Motorola term for CTCSS
P25 - Project 25, APCO's digital radio interoperabliity project
PRP - Peel Regional Police
PD - Property Damage, a fender bender type minor accident
PI - Personal Injury, an accident with injuries

-R-
RTC - Rail Traffic Controller, railway dispatcher and network controller
ROPE - Repeat Offender Parole Enforcement squad
RBU - Regional Breathalizer Unit, the Peel Regional Police unit responible for spotchecks and radar

-S-
SOCO - Scene Of Crime Officer, a specially-trained forensics collection officer on the Toronto Police force
SIU - Special Invesigations Unit, investigation team that probes crimes involving police officers or deaths caused by police activity

-T-
TPS - Toronto Police Service
TFS - Toronto Fire Service
TAC - Peel Regional Police Tactical unit
TSU - Traffic Services Unit (Toronto Police)

-V-
VSELP - Vector Sum Excited Linear Prediction, an early Motorola digital codec
VSA - Vital Signs Absent

-Y-
YO - Young Offender
YOA - Young Offender's Act (archaic)



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