JRC Response to the consultation on Ofcom framework for spectrum sharing

Availability of information: 

JRC notes that Ofcom could 'include information on actual use (rather than authorisations)'.

JRC is very concerned that Ofcom may publish information that could jeopardise the safety and security of the UK's critical national infrastructure (CNI), and seeks assurance from Ofcom that this will not be published.

JRC highlights that utility systems may be installed for resilience and / or emergency use only. Spectrum monitoring may therefore suggest that the channel is unused / under-used and it may erroneously be targeted for compulsory sharing.

JRC suggests that identifying ‘actual use’ may be appropriate for public sector spectrum but not private sector spectrum. This is because, for commercial operators, market economics are supposed to encourage sharingwhen it is in the financial interest of the parties concerned. Or does Ofcom wish to declare ‘market failure’ for spectrum?

JRC suggests that it should be up to the licensee to decide whether they wish to explore sharing options.

JRC therefore suggests that Ofcom creates a Spectrum Sharing Register for licensees considering sharing and thereby easily identify opportunities for sharing.

Market Barriers -Transaction costs: 

JRC highlights that, in any temporarily unused channels, it regularly shares itsspectrum with PMSE, typically within limited geographical areas, and other users within varying geographical areas. JRC strives to keep these short-term spectrum access authorisation costs realistic but these costs may appear prohibitive / excessive for some applicants when compared to the annual cost of a licence for similar narrow-band spectrum. JRC is working to reduce these costs.

Technological Challenges: 

JRC considers that the technological challenges are the most significant. This is highlighted by Ofcom’s recent decision to allow eight 5 MHz channels of broadband systems to be operated adjacent to existing systems operating in the 1.4 GHz band. The problem could have been significantly ameliorated if Ofcom had have taken the advice to designate the 5 MHz channel(s) adjacent to the existing systems as guard bands.

See Technological challenges, above.

JRC highlights that, as referred to in Technological Challenges, above, Ofcom acknowledged in its Consultation document that, without a guard band, there may be harmful interference to the existing adjacent 1.4 GHz users, but released all eight channels anyway. (That decision may impact hundreds of 1.4 GHz fixed links systems.)

JRC is therefore very concerned that Ofcom may again ignore the advice of existing licensees. If so, there may be a very real risk that existing and future licensees may perceive that no spectrum will be safe from interference. This could seriously reduce the value of spectrum.

JRC therefore recommends that Ofcom gives a definite reassurance that it will not ignore evidence-based interference concerns of its licensees in the future.

Uncertainty about the future: 

JRC is seeking access to 2 x 3 MHz of 400 MHz UHF spectrum for use by Utility Operations Networks (UON). In doing so, whilst there may be sharing opportunities available, there has been sustained resistance to share currently unused / under-used spectrum because the spectrum owner(s) fear that their long-term access to it may be lost.

This lack of spectrum means that JRC has to continue to seek out and licence individual 12.5 kHz channels as they become available. Sometimes suitable spectrum is so scarce in an area that JRC is forced to licence spectrum on a short-term only basis; with no guarantee that the subsequently installed system will continue to have access to the same channel after the short-term, e.g. 6-months, period expires.

The lack of contiguous 400 MHz UHF spectrum means that the utilities can’t roll-out the higher data rate systems, e.g. 64 kbit/s, which it is expecting to need for the management and control of Smart Grids.

Likewise, considering the interference problems identified above, the utilities are hesitant to roll-out further 1.4 GHz backhaul links for fear that these will also suffer harmful interference. Or, worse, the 1.4 GHz band be given up for more, say, 5 MHz channel systems.

Provision of information on spectrum use: 

JRC recommends caution when considering including 'Information on actual use, not just what is authorised'.

Publishing ‘actual use’ may be appropriate for the public sector, but is inappropriate for the private sector (unless the spectrum has usage obligations in the licence).

Publishing actual use of commercially licensed spectrum would be inappropriate for a number of reasons:

• Safety and security of, inter alia, critical national infrastructure (CNI);
• Radio services may be back-up or resilient paths, and therefore only used when the primary route fails; or contingency communications which only transmit intensively under fault conditions. The spectrum therefore appears to be empty and unused when monitored;
• Market sensitive (may affect a plc’s share price if precise roll-out details are published by Ofcom and this conflicts with their information to shareholders); and
• Commercially sensitive (in negotiations, one does not wish to reveal details of current spectrum usage).

It should be up to the licensee to decide if they wish to explore sharing options. For public sector spectrum holders, there may need to be an incentive by publishing usage data; but for commercial operators, market economics are supposed to encourage sharing when it is in the financial interest of the parties concerned. Or does Ofcom wish to declare ‘market failure’ for spectrum?

JRC suggests that it should be up to the licensee to decide whether they wish to explore sharing options.

JRC therefore suggests that Ofcom creates a Spectrum Sharing Register for licensees considering sharing and thereby easily identify opportunities for sharing.

Information on actual interference: 

JRC notes that Ofcom's licensing system currently uses a less than optimal coverage prediction algorithm and terrain data, e.g. for Business Radio licensing. Whilst this arrangement may be suitable for licensing purposes it may not be sufficiently accurate for accurate interference predictions.

JRC suggests that Ofcom prioritises the establishment of:

• the actual use of public sector spectrum; and
• a licensing method that will enable a public sector spectrum owner to sub-let spectrum without fear of their losing access to it over the long-term.

JRC suggests that Ofcom also assesses which spectrum users are an essential supplier for the delivery of almost all goods and / or services to UK citizens and consumers, and consider giving those suppliers appropriate priority with their spectrum requirements. (Hint: you till it is.)

JRC typically plans its systems for maximum spectrum efficiency. This can result in transmitter effective radiated powers (ERPs) of milli-watts (mW). These types of low-power systems require closely controlled noise-limited interference co-ordination.

As an example, JRC advises that there could be issues with listen-before-transmit (LBT) systems operating within fixed links spectrum and other systems that are typically designed to meet noise-limited interference co-ordination requirements, e.g. the wanted signal at the receiver, via its elevated position antenna, will only be a predefined number of dB above the noise floor. Whilst this will be a low signal strength, the licensed / wanted system will have been designed to receive a sufficient signal for it to communicate. If, however, a nearby listen-before-transmit (LBT) system is located indoors it may not receive sufficient / any signal to recognise that the spectrum is already occupied. This could result in harmful interference at that address and neighbouring properties.

JRC therefore suggests that spectrum in which noise-interference co-ordinated systems are deployed should not be used for systems with other types of co-ordination methodologies, e.g. interference-limited co-ordinated systems.

The proposed information may be useful for some potential sharers. JRC highlights, however, that its systems typically operate within closely controlled radio interference environments. This usually entails its being the only spectrum licensee within a wide geographical area. Ofcom's identifying which unused channels are available on a UK-wide basis, or at least within 50km x 50km very low undue interference level blocks, would also be very useful. 

JRC suggests that it would be useful to know which spectrum, by geographical area, is being used for 6.25 / 12.5 / 25 kHz narrow band communications and which spectrum is being used for wideband and broadband communications.

This may enable potential sharers to establish whether the spectrum may be operating in a high co-/ adjacent-channel undue interference level environment, and may need interference-limited co-ordination and / or wide geographic separation, and which spectrum may be operating in a low co-/ adjacent-channel undue interference level environment, and may only need noise-limited co-ordination.

JRC suggests that the Auctions heading should be expanded to Auctions and Awards. This may enable spectrum distribution to be based on the socio-economic value of use rather than merely which bidder has the deepest pockets and / or makes the most credible claims regarding sharing.

Spectrum trading and leasing:

JRC sees spectrum leasing as the simplest method of spectrum sharing for Utility Operations because it enables private negotiations with the incumbent user(s) without regulatory involvement.

JRC is able to share any temporarily unused spectrum easily because its spectrum management system takes into consideration all channels that it manages and allstations / links with which it needs to co-ordinate.

Spectrum pricing:

JRC highlights that the calculation of AIP values may sometimes be flawed.

A recent Ofcom consultation suggested that the 1.4 GHz band is now more valuable because it could be used by public mobile operators. That part of the band, however, is not harmonised for public mobile use so is unlikely to be valued highly by mobile operators until it is harmonised, if ever.

As such, there is a reputation risk to Ofcom that it could be seen as attempting to artificially inflate the licence fees for the 1.4 GHz band in order to promote the migration of fixed links users from the band and / or to increase the financial benefit of the Treasury.

Auctions [and Awards]:

JRC suggests that the Auctions heading should be expanded to Auctions and Awards. This may enable spectrum distribution to be based on the socio-economic value of use ratherthan merely which bidder has the deepest pockets and / or makes the most credible claims regarding sharing.

White Space sharing:

JRC is pleased to see that the initial white space use will be on a licensed basis. This will enable the spectrum to be recovered if the proposed sharing scenario is less effective than it is hoped.

Overlay auctions:

JRC is concerned that the 450 to 470 MHz band could suffer an overlay auction. This could result in the UK's Utility Operations losing essential access to its current 2 x 1 MHz spectrum, plus many other narrow band UHF channels, with no alternative spectrum being available in which to migrate its systems.

JRC is also concerned that LTE systems may be being considered for use between 450 to 470 MHz. If so, JRC would like to highlight that there is a second part to the often, only, quoted first part of ITU footnote 5.286AA:

‘The band 450-470 MHz is identified for use by administrations wishing to implement International Mobile Telecommunications (IMT). See Resolution 224 (Rev.WRC-07)*.

This identification does not preclude the use of this band by any application of the services to which it is allocated and does not establish priority in the Radio Regulations. (WRC-07)’

JRC does not suggest any additional enablers.

JRC suggests that each of them may be feasible to facilitate sharing.

JRC advises that there could be issues with Carrier Sense Multiple Access (CSMA) systems operating within white space and other spectrum. For example, at the boundary of broadcast service area, a TV antenna mounted at 7m may enable a sufficient signal to be received. Conversely, at the same address, the CSMA system may be located indoors and positioned much lower so it may not receive sufficient / any signal to recognise thatthe spectrum is occupied. This could result in harmful interference at that address and neighbouring properties.

JRC recommends that Ofcom should participate sufficiently within any national and / or international negotiations so as to ensure that subsequent UK policy decisions wouldn't result in a 'good' solution that is ideal for, say, 80% of the stakeholders but unacceptable for the remaining 20%. A ratio of 95:5 may be seen as an acceptable ‘good’ solution. 

Information requirements:

JRC notes that Ofcom could 'include information on actual use (rather than authorisations)'. JRC is therefore very concerned that Ofcom may publish information that could jeopardise the safety and security of the UK's critical national infrastructure (CNI), and seeks assurance from Ofcom that this will not be published.

JRC suggests that broadband spectrum that is licensed but unused, or has only token use / coverage, in remote rural areas could be shared with other users. JRC recognises, however,that it may not be possible fornoise-limited interference utility systems to co-exist withgeographically adjacent and / or spectrally adjacent broadband systems.

Tiered access:

JRC highlights that its systems typically need to beinstant / priority accessso sharing spectrum with other users with equal access rights may be an issue.

JRC suggests that, with the ever-increasing amount of spectrum being allocated for public mobile use, there should be increasednarrow band 12.5 kHz channels allocated for, say,Light Licensed Simple Site and Simple UK systemsand PMR446-type systems. These allocations should ensure that narrow band private mobile radio (PMR) / Business Radio systems will always be available for those that depend on them; albeit with the potential for harmful interference whensharing within these scenarios.

JRC suggests that each of them may be feasible to facilitate sharing.

JRC believes that may licensees will prefer not to divulge their geographical spectrum use for the reasons given above.

Whilst the proposed characteristics of use may be sensible, please see 8b, below.

High-level technical characteristics:

JRC recommends including transmit mask characteristics, receiver sensitivity, receiver rejection, and other characteristics that highlight how spectrally efficient within its licensed channel width a system is. For example, see the interference problems resulting from the recently agreed 8 x 5 MHz channels in the 1.4 GHz bandinto the adjacent noise-limited interference planned fixed links networks.

JRC is pleased to note that Ofcom recognises that there is no ‘one size fits all’ solution.

JRC suggests that broadband technologies / systems should not be given automatic preference over narrow band technologies / systems. For example, see the 8 x 5 MHz channels in the 1.4 GHz bandcomments above.

JRC suggests that Ofcom gives consideration to every technical characteristic before considering mixing noise-limited systems with interference-limited systems.