The 28 GHz band (27.5–29.5 GHz) is currently the only band that supports 112 MHz channel sizes for fixed point-to-point (PTP) applications. These channels are commonly used to support backhaul for high data rate services.
As part of the review of arrangements in the 28 GHz band, the ACMA investigated moving these arrangements to alternative bands. The 38 GHz band (37.0–39.5 GHz) was identified as a viable option. Therefore, the ACMA proposed to include 112 MHz channel size in RALI FX3 supporting PTP demand for higher channel sizes.
During consultation, some respondents requested the inclusion of 56 MHz channel sizes, in addition to the 112 MHz channels. The ACMA found 56 MHz channelling arrangement would provide a logical inclusion with 28 MHz and 112 MHz channel arrangements and would provide industry additional flexibility in designing a network to meet their business cases.
After assessing submissions to the consultation process, the ACMA has decided to:
- implement arrangements supporting 56 MHz and 112 MHz channels in the 38 GHz band
- retire 7 MHz and 14 MHz channel sizes from 38 GHz band
- support continued operation and protections of 7 MHz and 14 MHz licensed service for the foreseeable future.
The ACMA received four submissions to this consultation. These can be accessed from the right hand side index box, under 'Other submissions received'.
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Review of point-to-point arrangements in the 38 GHz band
Introduction of 112 MHz channels for fixed point-to-point links in the 38 GHz band
The ACMA is currently reviewing spectrum arrangements in the 28 GHz band. An options paper released in April asked for views on whether various services, both new and existing, should be supported in that band.
Proponents of fixed point-to-point use in the band expressed a desire to maintain the existing arrangements as the 112 MHz channel size is unavailable in any other fixed point-to-point band. These channels are commonly used to support backhaul for high data rate services.
Due to the current limited usage of the 28 GHz fixed point-to-point arrangements and demand for access to the band by other services, the ACMA began investigating the use of other bands for higher bandwidth channels. The 38 GHz band was identified as the only possible band that could accommodate an effective 112 MHz channel raster.
As such, the ACMA is proposing changes to the current arrangements in the 38 GHz band (37.0–39.5 GHz) in RALI FX3 to support the changing needs of industry and technology advances in the use of fixed point-to-point links. The ACMA is seeking comments on these proposed changes.
The 38 GHz band currently supports channels with 7 MHz, 14 MHz and 28 MHz bandwidth. This paper proposes updates to RALI FX3 to:
- add arrangements for 112 MHz bandwidth channels to the band
- remove arrangements for 7 MHz and 14 MHz bandwidth channels from the band
- grandfather any existing 7 MHz and 14 MHz bandwidth assignments currently in the band.
Issues for comment
The ACMA welcomes comment from interested stakeholders on all aspects of the proposed changes and additions to the 38 GHz band in RALI FX3. These are discussed in the consultation paper and can be seen in their entirety in Appendix 2.
Specific questions are featured in the relevant paper and collated below. Details on making a submission can be found in the ‘Invitation to comment’ section at the end of the paper.
- Are there any alternative proposals on the channelling arrangements in the 38 GHz band that the ACMA should consider?
- Are there any comments on the proposed implementation of 112 MHz channels in the 38 GHz band?
- Are there any comments on the proposed retiring of the 7 MHz and 14 MHz channels in the 38 GHz band?
- Do stakeholders have comments on the grandfathering arrangements for the 7 MHz and 14 MHz assignments in the 38 GHz band?
- Are the proposed protection ratios appropriate for the band?
- Are there any comments on the assumed percentage of time to be used?