MARITIMES SCANNING SITE

800 MHz and its Use in the Maritimes, 
with special mention of the NSTMRS

Last updated November 24, 2006

© 2007, MARITIMES SCANNING SITE, all rights reserved

This page refers to the 800 MHz non-cellular band as it is presently configured in Canada, 
and which is being substantially modified in the USA.   

The 800 MHz frequency range is made up of several parts, including the oldest of the cellular telephone bands (824-849 and corresponding 869-894 MHz) The land mobile band portions of 800 MHz are:

Industry Canada states that despite anything in the current specifications it can authorize different ways of using the spectrum in particular cases, including the use of interstitial frequencies lying between those shown in the standard channel plan.

In order to follow my comments you should print my 800 MHz band-use Excel files which not only tell you who in the Maritimes is on what channel, but will make the pattern of assignments much clearer than words alone can do.   This is available in the regular frequency order format.  This list also includes much information about all bands in the 700 and 900 MHz range.    You can also access 800 MHz information ordered by trunk block and group.  The latter will make the frequency structure of the various trunking systems in the Maritimes stand out and maybe make sense.  

[Excel File comments:  due to technical difficulties some assignment comments are truncated so that the final parts of long entries may be missing; however I think that it is slight enough that you will see all assignments.   TB stands for trunk blocks, the major divisions that Industry Canada has divided the 800 MHz spectrum into.  These are subdivided further into Trunk Groups.  Normally any one trunk site will have a set of frequencies or channels assigned from one trunk group such as 361, and additional ones from the next group ending in the same number, such as 311 or 411 (50 up or down).   Also please note that I have not given structure details for the 866 MHz sub-band as that does not presently have any trunking systems in the Maritimes.]

Generally speaking, and particularly in the USA, emergency service providers will use the 866-869 MHz Band, and this band also includes the standard interoperability simplex frequencies.    Listeners in the Maritimes may wonder at this, because the Nova Scotia TMR uses frequencies below 866, in fact below 863 MHz and it is full of public service traffic.  The answer to this is that the TMR is licenced to Bell Aliant and is open to a wide range of users.   The RCMP, EHS, Fredericton PD and others merely rent space on what is essentially a commercial system.   You will note that the conventional frequencies used by these public service users will usually be found at 866 MHz and higher, as those frequencies are licenced to the public service users directly.  Please note also that as a result of that, TAFL will not show some 866-869 MHz assignments as police and other security oriented licencees are excluded from public listings in Canada.

In areas within 100 km of the USA border the frequencies are divided for exclusive or protected use by one country or the other.   In the Excel files mentioned above  the American frequencies are indicated, with the others being Canadian.  Between 100 and 140 km the US frequencies may be used in Canada, but with reduced ERP and vice versa.   Beyond 140 km all channels are usable by both countries.  Note that exceptions are made, for example you will note that some Nova Scotia simplex frequencies in the 866 MHz band are actually US channels but being simplex there is no likelihood of interference.   Still, this restriction does mean that the possibilities for channel assignment are much less in the western half of New Brunswick and in SW Nova Scotia than they are elsewhere in the Maritimes.

All channels are designated for duplex use, i.e. two frequency use.   Where an assignment has been made for simplex use it appears to be that this will always be for the higher frequency side, not for the lower one.   In fact the regulations do not talk about simplex but rather about talk-around, the use of the base frequency (upper) by mobile users.

The Commercial 851 MHz band begins with a channel-centre frequency of 851.0125 MHz (Channel 001) and extends continuously to 865.9875 MHz (Channel 600).   Each channel is 25 KHz wide.    Each channel is 25 kHz higher than the previous one.

The Public Service 866 MHz band begins with a channel-centre frequency of 866.0125 MHz (Channel 601) and extends discontinuously to 868.9875 MHz (Channel 830).   While channels are generally 12.5 kHz higher than the previous one, there are a number of designated international operability channels that are made up of an actual 12.5 kHz channel plus a guard band of 12.5 kHz above and below, so that in effect each of these operability channels takes up 37.5 kHz

There are five interoperability channels that are designated to be used by emergency service providers and other public service users in both countries and in fact the intent is that all such users of 800 MHz would have these five frequencies in their radios, as the purpose is to allow easy interoperability.   The five channels are separated from each other by 500 kHz to ensure that there is no mutual interference when more than one is being used in close proximity such as at a particular incident.   Like all other 800 MHz channels they are two frequency at least in theory, for repeater use, but in fact they may be assigned or utilized more often as simplex (talk-around) channels, with only the high frequency of the pair being actually used.  If CTCSS tones are used on these channels, it must be 156.7 Hz. 

Interoperability channels (only the higher frequency is shown,  a repeater input is also technically part of these designations):

I-CALL         866.0125 MHz  (International Calling)
I-TAC 1        866.5125 MHz  (International Tactical 1)
I-TAC 2        867.0125 MHz  (International Tactical 2)
I-TAC 3        867.5125 MHz  (International Tactical 3)
I-TAC 4        868.0125 MHz  (International Tactical 4)

Note that although the channels are designated "international" and may be used cross-border, they do not have to be cross-border.  International refers to the fact that these channels are standard in both countries.   It is unclear as to whether the intent is to use these frequencies only for interoperability.   It may be of interest to note that in the Nova Scotia environment, I-CALL and I-TAC 1 are designated locally as Simplex All 1 and Simplex All 2, and available to all provincial government users, and perhaps the majority of other public service users.   The other I-TAC's are assigned to particular government departments and may not actually be in all NS government radios, which appears to be counter to the intent of the 5 channels.   It is also apparent that some public service users within the NSTMRS umbrella do not have any of these five channels!

In the 866 MHz public service band, there are 3 categories of eligible users:

Category 1: police, fire and emergency medical
Category 2: Agencies contributing to public safety
Category 3: Other government agencies as well as supervisory personnel of such entities as utility companies or other non-governmental entities, whose participation would be for the benefit of the public.

Category 1 are eligible to operate systems.  Category 2 are eligible to share systems providing they are not the major user.  Category 3 would normally include those who do not actually operate the systems in this band but may be permitted access during emergencies but with the channel under control of the major users.  An example would be an electricity company supervisor, who may be allowed access to public service operated systems in times of emergency for liaison purposes.

 

Trunking:

Industry Canada guidelines for trunking include the following major points, which refer in their specifics to the Maritimes and not necessarily to other parts of Canada. Frequencies (channels) are assigned in predetermined groups.  Most groups are made up of five sequential frequencies,  so that each frequency for a particular site is 250 kHz or ten channels higher than the one below it.  For example the "Family 1A"  NSTMRS sites (such as at Wakeup Hill) initially have five frequencies in a group named after the first frequency in the group, in this case Group 361.

The NSTMRS is based on sets of 2 consecutive groups of five channels, for a normal total of ten.  Let me explain.   Continuing on from the group shown above is Industry Canada Group 411:

This group is assigned on what I have elsewhere called Group 1B sites, such as at Prospect.   In the TMR organization, the two consecutive groups are usually assigned to a pair of sites that are relatively close to each other, and therefore I refer to them as pairs, so that Wakeup Hill and Prospect are a pair.  In my discussions of the TMR on other pages I refer to this pair of groups or the sites that are in it as Group 1 or Family 1 because all the channels end in the number 1, and then divided it into 1A (lower group) and 1B (higher group).   My designations are entirely unofficial and simply for convenience, and I will gradually replace them with these official designations.

On the other hand a site that requires more than five repeater channels would be assigned BOTH groups, for a total of ten channels.  For example the busy Sackville site has both Group 362 and Group 412 and therefore has available all the normally allowable frequencies that elsewhere in the system would be divided among two sites.

It has come to pass that some sites in the very busy areas of the NSTMRS require even more than ten channels and Industry Canada has allowed the use of even more frequencies, usually from even lower groups in the same sequence.  For example for a site using both Group 361 and 411, the next usual would be to use one or more frequency from Group 311 or even a lower group such as 261; however in a few cases busy sites are using channels from other sequences of groups.

When assigning less than a complete group of five channels the preference by IC is to begin with the lowest channel in the group.  

Careful perusal of the Excel files will reveal that trunk blocks J and  L have only 4 channels in each group, and that Block E has 7 channels, and in with frequency gaps, so that for example in Block E, in Group 141, the first channel is of course Channel 141, but the next one is not 151, it is 251!

While not apparently part of the Industry Canada regulations, it is standard in the NSTMRS to use the first channel in the assigned group as the normal data (control) channel and the next one up as the alternate.   Other trunk systems in the Maritimes do not necessarily do this and may have several rotating control channels.   NSTMRS sites with more than one 5-channel group may use the first (lowest) channel in either group.  For example Sackville which uses Groups 362 and 412, uses the lowest channel in Group 412  for the main data channel, not the lowest channel of Group 362.