Proposed updates to RALI LM8 land mobile service frequency assignment requirements | ACMA

Proposed updates to RALI LM8 land mobile service frequency assignment requirements

IFC 42/2014 — 22 September 2014


After considering issues raised in submissions and discussing issues raised with respondents a revised version of RALI LM 8 is available here.

Changes made from the consultation draft have been to clarify arrangements for supplementary base stations, height power restrictions, intermodulation calculations. 


A number of changes have also been made to the frequency-distance constraints from the consultation paper.  In summary these are:

  • Frequency-distance constraints are now symmetrical and based on worst case values.  That is, values for new 6.25 kHz to existing 12.5 kHz are the same as new 12.5kHz to existing 6.25 kHz with worst case values being used.
  • For low powered systems, to address concerns about small separation distances in low powered systems when channel bandwidths overlap, in such circumstances distances have been set at 10 km.
  • Adjusting 1st adjacent channel separation for 12.5 & 25 kHz high powered two frequency systems to  be 0 km.  Rationale being that either  performance will be  better than modelled and any degradation  in adjacent channel performance will be limited to mobile receivers  at  edge of the 40km service area (ie 37-40 km)  in close proximity to unwanted base station.
  • Reference levels for 25/12.5 kHz systems are to be the same.  For 6.25 kHz systems levels will be adjusted by 3 dB in recognition of smaller bandwidth.
  • Calculating separation distances by determining a reference propagation loss at the co-channel separation distance and using the FDR values to determine what loss (and hence distances) are required at other frequency separations.

Enquires about the update should to send  to the Manager Spectrum Engineering by email to

Submissions received

Submissions closed on the 22 September 2014 and the ACMA is considering submissions received. Eleven submissions were received from the following organisations:


On 22 September 2014 the ACMA sought comment on proposed updates to the current frequency assignment requirements for the land mobile service contained in Radiocommunications Assignment and Licensing Instruction (RALI) LM8.

The proposed changes and rationale to the changes are outlined in :

  • The discussion paper, Proposed updates to RALI LM8 land mobile service frequency assignment requirements (Word 592 Kb)
  • The spectrum planning report, Derivation of 400 MHz band land mobile frequency distance constraints used in RALI LM8 (Word 630 Kb)
  • Proposed amendments to RALI LM8 Frequency Assignment requirements for Land Mobile service (Word 255 Kb).

A copy of the existing RALI LM8 is available here.


Submissions are invited from interested parties on the proposed changes by COB Monday 3 November 2014.

Submissions should be sent:

By email to:

By mail to:
Spectrum Engineering Section
Spectrum Planning and Engineering Branch
Australian Communications and Media Authority
PO Box 78
Belconnen ACT 2616

Last updated: 17 December 2018