2009 806-960 MHz Band - NZART Comments

29 June 2009
Mr Brian Miller
Manager, Radio Spectrum Policy and Planning
Radio Spectrum Management
Ministry of Economic Development
P O Box 1473
WELLINGTON 6015

Dear Brian,

806-960 MHz Band Re-Planning Options Discussion Paper - NZART Comments

Thank you for the opportunity to comment on your discussion paper on the re-planning of the 806-960 MHz band. From our understanding of the current proposals:

* the only New Zealand Amateur allocation that will be affected by this study will be the 921 - 929 MHz band which we share with Short Range Devices (SRDs); and

* within this band, Amateurs will be affected by your proposal to allow increased power for SRDs in the sub-band 920-926 MHz.

While we understand the desire for increased power for some SRDs, we are concerned that the effect of this will be to significantly reduce the usefulness of the 900 MHz band for Amateur activities unless some other changes are made at the same time. We are therefore requesting that, if the proposed changes to SRD band and allowable powers proceed:

* the 900 MHz Amateur band be likewise extended to match the expanded SRD band (so that we continue to have access to "quiet" parts of the 900 MHz spectrum); and

* the power limit for Amateurs is raised from the current 25 to 100 watts eirp. The reason for these requests is given in the attached NZART Commentary.

Once again, we would like to thank you for the opportunity to comment on your Discussion Paper and we look forward to further constructive dialogue on the issues it raises.

Regards

Don Wallace

NZART Administration Liaison Officer.

806-960 MHz Band Re-Planning Options Discussion Paper - NZART Commentary

NZ Amateurs currently have an allocation at 921.00 to 929.00 MHz. The band is also designated for industrial, scientific and medical (ISM) purposes and these frequencies may also be allocated to Short Range Device (SRD) services. Amateur operators must accept interference from ISM and SRD services within these frequency ranges and our radiated power must not exceed 25 watts eirp.

The Proposal

The Ministry of Economic Development is currently looking at re-planning the 806-960 MHz Band and, as part of this is proposing to extend the Short Range Device allocation and to increase the allowable power for SRDs in part of the expanded band.

The proposals are covered by Question 11 of the 806-960 MHz Band Replanning Discussion Paper which asks:

Is the proposed expansion of the SRD allocation to 915-929 MHz, along with an increase in power from 1 watt to 4 watts for RFIDs operating at 920-926 MHz, viable and appropriate in New Zealand? If not, please explain.

NZART View On The Proposal

The NZART view on the two matters canvassed in the proposal are:

* We have no view on the proposal to extend the band¹; and

* We would prefer that the SRD maximum power is not increased.

The reason for our view is that the effect of raising the SRD power by 6dB will be to raise the noise floor by a similar amount wherever these higher power devices are used making it more difficult for Amateurs to communicate on these frequencies.

An Alternative Solution

NZART recognises that there are a number of factors that may influence the Ministry toward allowing higher power SRDs in the 920-926 MHz sub-band:

* there is a wish/need to increase the maximum SRD power - particularly for reading of RFID devices at a distance;

* Australia has designated the sub-band 920-926 MHz for higher power SRDs; and

* other countries use similar frequencies for high power SRDs.

If a decision is made to allow higher power SRDs in the 920-926 MHz sub-band, we propose that the following changes be made to the Amateur allocation to mitigate the effect of higher power SRDs on Amateur communications:

1. the power limit for Amateurs be raised from the current 25 to 100 watts eirp and

2. the 900 MHz Amateur band is extended to match the expanded SRD band.

The reason for these request are as follows:

1. Power Limit: The proposed increase in SRD power by 6db will lead to a corresponding increase in the noise level in the 900 MHz band wherever these high power devices are used. This will include, we understand, ports, airports, industrial areas and other areas where it is necessary to read RFID tags from a distance. Raising the permitted Amateur power level by 6 dB will mean that the current margin between Amateur and SRD transmit power will be maintained, meaning that Amateur communications should not be too badly affected by the change in SRD power level.

2. Band Extension: While the use of higher Amateur transmit powers will, in theory, mitigate the noise caused by high power SRDs, it is neither practicable (nor desirable) to use such high powers in some types of (e.g. portable/battery powered) communications. We are requesting access the proposed new part of the band (915 - 921 MHz) as this part of the spectrum will be suitable for communication between devices that are operating at lower powers as it will only be used by lower power (maximum 1 watt) SRDs.

Conclusion

As noted above, the most desirable solution of Amateurs is for no changes to be made to the maximum allowable SRD power in the 921 to 929 MHz band.

If, however, a decision is made to allow higher power SRDs in the 920 - 926 MHz part of the band, the negative effects of this change could be mitigated if:

1. the power limit for Amateurs is raised from the current 25 to 100 watts eirp; and

2. the 900 MHz Amateur band is extended to match the expanded SRD band.

Footnote

1. This assumes that the power limit is NOT increased.