Appendix B: Summary of Submissions

Q1
demand for 400 MHz STL licences

Q2
Better utilisation of 900 MHz spectrum

Q3
5 km min path length

Q4
Managing increase in SRD

Optimise the channel allocation, polarisation & antenna type, especially at the RX end. Use multiplexing where appropriate.
Clarify the policy for 400 MHz channels

Yes provided appropriate and cost effective solutions are available.
May encourage migration to fixed lines but cost implications make these unattractive.

Needs further analysis of the interference potential of SRDs likely to use the STL band

Cobalt Tech
(Mosely)

Could be used for stereo quality links using digital technology. e.g. 300 kHz at 64 QAM.

Using digital STL provides two uncompressed stereo channel pairs in 500 kHz at 64 QAM.

Not supported. Encourage studios to move outside the min distance.

Digital STL enable a migration to less spectrum use and possible sharing with SRD in some cases.

Likely to decrease because of higher noise level. Should be phased out as inappropriate for STL

Reduce channel spacing to 200 kHz with cross polar or 300 kHz co-polar.
Digital modulation using up to 256 QAM & bit rate reduction.

Yes to encourage appropriate use of spectrum and modulation mode

Increase education & enforcement to minimise the effect of SRD

Felt actively discouraged by MED to use band. Expect demand up to same rate as 900 MHz

Tests of a digital STL are currently underway.
Bench tests showed latency and audio performance to be acceptable.

Not supported. Alternative terrestrial circuits have been found to be unreliable in urban areas

If higher power SRD permitted then new band required for STL with long migration period and financial compensation.
Conflict is considered of Ministry's making in original allocation of STLs.

Likely to be more demand now that industry is aware of its availability

Possibly reduce channel spacing to 250 kHz but incompatible with older equipment.
Digital equipment may have a role provided it does not degrade the audio quality (compression and latency)

Not supported because it would favour studios just outside the limit and not fulfil the market needs fairly.

Maintain the 3 mW limit and enforce the regulations where interference occurs.

Demand would be similar to 900 MHz if made available for general use

Digital may provide x2 increase. Compression is not an option

Problem of Ministry's making. Financial compensation may be required if migration to other band is required

Against the use of digital STL because they degrade the QOS while having little practical improvement in C/I.
Cost per link is $25-30k.
Recommend using higher frequencies in 1.4-2.4 GHz band already used in Europe.

Increase the STL power budget by 20-30 dB and use more directive antennas.
Move to alternative spectrum such as 1.4-2.4 GHz band already used in Europe.

Embargo on new licences and encouragement to migrate from land mobile bands should remain.

Use higher gain antennas.
Multiplex multi channels over the same path.
Landline links especially over short paths are low cost and readily available into the major transmitter sites.

Some demand if ministry imposed embargo removed. Some AM stations using 900 MHz when could use 400 MHz. Migration of these licences could free up some 900 MHz spectrum.

Digital STL cost $11k
Leased line $8.4k/an
Analogue composite STL $7k
Therefore strong cost incentive to use analogue STL.
Newcomers should not be asked to negotiate with existing licence holders to free up spectrum. This is a Ministry role.

Plan to migrate STL into new spectrum and require more directional antennas, lower power and multiplexing where appropriate.

Issues of latency and cascaded compression need to be addressed before encouraging migration to digital STL.
Use licence fee differential or fee holiday as incentives to migrate to digital.

Ref ITU-R guidelines for digital link design.

Antenna requirements should be used to improve spectrum utilisation but they should be specific to each case.

Additional bands which could be considered for STL are 845-849 MHz and 935-939 MHz.

Cobalt Tech
(Mosely)

Bundle the STL licence with the broadcast licence. This would enable the Ministry to change STL licences to digital as demand dictates.

C/I for co channel at 16 QAM is 16 dB.
C/I for adjacent channel at 16 QAM is -32 dB

Limited benefits because often many of the links to a broadcast site are in a similar direction.
Drawbacks are size, weight, wind loading and RMA issues.

Use of 5.8 GHz as an alternative delivery mechanism for multiplex programmes plus phone and data services.

Higher licence fees for inefficient techniques plus sunset clauses.

Yes for all new licences plus two years for existing licences to upgrade

Consider 1.5 GHz as a more appropriate band

Provide assistance in establishing feasibility.
Identify a band for digital only with no sharing with other devices

20 dB fade margin to overcome multipath effects
-65 dBm unfaded receiver input.
Stay with 500 kHz channel spacing

Not supported because of size and RMA issues.
Not expected to produce much benefit because of configurations around major transmitter sites.

Any sudden change to STL requirements could threaten the viability of a flexible, low cost and reliable broadcasting environment.

RSM to facilitate temporary changes to licences to permit testing of digital STL. Maintain current channel plan and use digital to enable multiplexing more audio channels per radio channel.

20 dB fade margin to allow for multipath vulnerability of digital modulation.
A study of protection ratios is required to determine engineering guidelines.

Not supported. Major problems with size and weight on towers. The benefits would be marginal in many cases because the paths towards the TX site are often from similar directions.

Agrees with the future growth in radio stations requiring more STL licences. Additional spectrum identified as soon as possible.

Assist with compatibility tests. Allocated a digital only band.

Yes if it helps. Maybe RMA issues for larger antennas

STLs have a 15-20 year attrition period.
Radio solutions are preferred because of their low cost and high QOS.

Introduction of directional antennas, a review of the necessary power and an embargo on new licences for the same operator on the same path.

The Australian antenna specification should be mandatory. Only the minimum power levels required for each path should be allowed.

In congested areas there should be technical justification why land line systems should not be employed

Analogue output from studio and into TX suits analogue STL. Further processing in digital STLs degrades signal quality and increases cost.

Improved antenna engineering may provide some benefits.