ANN on DMR

Many years ago, when I had (a lot more) shoulder-length hair; smoked cigarettes and drank beer, the most popular trunked radio technology was MPT1327. In those days, even Nokia made two-way radios - they had their own flavour of MPT1327 called Actionet which used a dialling scheme known as ANN.

Like MPT1343, ANN (Algorithmic Network Numbering) attempted to make calling other radios and talkgroups easier by segregating radios and talkgroups into fleets  thereby reducing the number of digits one needed to dial, in most cases. You have to remember that in those days, two-way radios could only store a small number of contacts (address book), so users would need to manually dial numbers to some extent - if they had that capability.

For example, to call a radio with an MPT1327 ident of 000-0001, the user would only have to dial 21, if MPT1343 was used and the target radio was in the same fleet. Had MPT1327 been used, the user would have to dial 0000001, inclusive of the leading digits.

How is this relevant to MOTOTRBO? Well, a MOTOTRBO radio can be used on a DMR Tier 3 system from another vendor and other vendors radios can be used on a Capacity Max system. 

To support a seamless migration from MPT1327 to DMR some vendors have carried over numbering systems like MPT1343; flat and ANN onto their DMR Tier 3 offerings. MOTOTRBO only supports the standard numbering scheme also known as the DMR Air Interface ID - that is if the radio ID is 1, 1 is what is what the user would dial and what would be sent over the air.

If ANN, or one of the other numbering schemes are be employed, the user dials one number but the radio will transmit something different.

To support other vendors numbering schemes, there needs to be a means to convert the ANN number (in this case) to the DMR AI number!

Like MPT1343, ANN defined a means to divide MPT1327 numbers into prefixes, fleets; groups and individual numbers. To do this, it used the following parameters:

Numbering Model. Normally, there would have been three choices: small; medium or large. This selection would determine the length of the prefix and consequently the number of prefix digits. Like MPT1343 to some extent, an ANN radio number is made up of a leading digit; prefix and ident. The user would dial all, or part of, the ANN digits and the radio would send the required MPT1327 number over the air as part of the call setup.

For a large fleet, the prefix length would be 2 and the length would be 7.

For a medium fleet, it would be 1 and the length would be 6.

And, for a small fleet it would be 0 and the length would be 5.

Fleet Partitioning Parameter (FPP). This value (0 to 10) allows the ident range into a number of fleets. The sum of FPP and MEP cannot exceed 10.

Miniaturization Extent Parameter (MEP). This value defines how many digits are used in the ident range to partition it into so-called minifleets. The sum of FPP and MEP cannot exceed 10.

A radio or talkgroup number in ANN format would consist of:

Leading Digit. This is a number in the range between 7 and 9.

Prefix. This is a number in the range between 00 and 99 for a large fleet; 0 and 9 for a medium fleet and omitted completely for a small fleet.

Unit Number. This is a number either between 20 and 99 for small fleets or 200 and 998 for large and medium fleets. In either case, 90 to 99 or 900 to 998 are reserved for talkgroup calls and 999 for emergency calls.

The format of the number would be:

leading digit; prefix; unit

The number of digits used will depend on the numbering model setting.

ANN >> DMR

In order to convert the ANN number to the DMR Air Interface ID, one will need to know what the FPP and MEP are.

 

If the value of FPP is less than a, to convert, use the following formula:

 

i = (a * 800) + 2 + (b – 200)

 

Where:

 

a = the 4th digit from the left in the ANN number.

b = the 3 last digits of the ANN number if a is less than FPP.

i = DMR Air Interface ID (what the radio/system uses and what goes in a MOTOTRBO radio).

 

If the value of a is equal to, or greater than the FPP, use one the following formulae:

 

If c < 100 – (MEP *10) and 20 ≤ d ≤ 41 then it is a small fleet and i = (c * 80) + 2 (d – 20)

If c > 100 – (MEP *10) and 20 ≤ d ≤ 41 then it is a mini fleet number and i = ((l - 7) * 22) + (c * 80) + 2 + (d - 20)

If c > 100 – (MEP *10) and 90 ≤ d ≤ 99 then it is a mini fleet number and i = ((l - 7) * 4) + (Rr x 80) + 70 + (UU - 90)

 

Where:

 

l = the first (leading) digit of the ANN number. 

c = the 4th and 5th digit from the left in the ANN number.

d = the last two digits of the ANN number.

i = DMR Air Interface ID (what the radio/system uses and what goes in a MOTOTRBO radio).

 

For example, to convert ANN 7000301 with a FPP of 10 and a MEP of 0:

7-digit string so a large fleet.

a = 0

b = 301

i = (a * 800) + 2 + (b – 200)

i = (0 * 800) + 2 + (301 – 200)

i = 0 + 2 + 101

i = 103

DMR>>ANN

In order to convert a DMR radio ID to ANN, one will also need to know what the FPP and MEP are.

If i < (FPP * 800) + 2 then l = 7; f = ((i - 2) / 800) and g = i - 2 - (f * 800)  + 200.

If MEP = 0 then l = 7; f = ((i - 2) / 80); g = i - (f * 80) +18.

If f  < (100 - (10 * MEP)) then l = 7; f = ((i - 2) / 80); g = i - (f * 80) +18.

If f  ≥ (100 - (10 * MEP)) and  ANN is a Radio ID then l = 7; f = ((i - 2) / 80); g = i - (f * 80) +18.

If f  ≥ (100 - (10 * MEP)) and  ANN is a Talkgroup ID then l = 7; f = ((i - 2) / 80); g = i - (f * 80) + 20.

The ANN number would be made up of 5 to 7 digits depending on the numbering scheme. The first digit of the string would be equal to l.

g = the last two or three digits of the ANN number.

i = the DMR radio or group ID.

f = the 4th or 4th and 5th digit of the ANN number

l = the first digit of the ANN number

I have searched my records and have only come across two records of customers, who used a MPT1327 system with ANN. The overwhelming majority of MPT1327 systems I've come across have used the  MPT1343 dialling scheme.

If anyone has access to a system which uses ANN, I'd appreciate of you could validate the above formula. If you get a registration denied, could you tell me what the allocated/programmed ANN and DMR ID were so I can get a few more (known good) data points.

If your DMR Tier 3 radio/system is using MPT1343 numbering, check here. If you're using 'flat' numbering, have a look at this post.