Articles Tagged ‘Larkhill Consultancy - white spaces’

Broadcast/Mobile Broadband convergence – the slow road to nowhere?

EC Spectrum Policy Workshop -Broadcast/Broadband convergence 04 November 2014, Brussels

As part of its policy deliberations on the long-term future of the UHF bands, the European Commission commissioned a study on the options for Broadcast/Mobile broadband convergence. The findings from this study follow the report from the working group led by Pascal Lamy. The Lamy report recommended that broadcasting be cleared from the 700 MHz band by around 2020, with security given to broadcasting in the remaining 470-690 MHz until at least 2030 – with a review of the situation in around 2025.

The study whose findings were presented in the workshop reviewed a number of options for rolling back traditional broadcasting and introducing a ‘mobile-friendly’ downlink into the UHF band below 700 MHz (after rejecting options using the band above 700, except to provide an uplink). This downlink would displace the traditional high tower/high power broadcast network but could use DVB or LTE technology (which would use lower power lower tower deployment, supporting the greater coverage density needed to achieve a greater mobile user satisfaction).

In summary, the study found that the technical and regulatory foundations for convergence were not yet in place sufficiently to get a clear picture of costs and benefits. It recommended further work on the technical foundations and a further review of the situation in 3 to 5 years’ time.

Given the slow pace of work on the 700 MHz band, together with lack of clarity on the technical foundations for broadcast/mobile broadband convergence (and the commercial interest needed to make it happen).

Meanwhile convergence is moving quickly for mobile device users, with Wi-Fi being the predominant network technology for delivering audio and video services to mobile devices of all shapes and sizes. LTE is integrated in nearly a fifth of tablets and this figure may grow, but the purchase cost penalty (typically an extra £100 on an iPad, for example) will likely limit the share of market achieved. On the other hand, the lower cost Wi-Fi will be built into an increasing range of mobile/portable devices – including cameras and other types. Wi-Fi has a clearer roadmap, with fewer bands and variations to burden implementation, so it seems likely to remain the network interface of choice for mobile/portable applications for years to come.

In Europe at least, we’d have to agree with Pascal Lamy that there is little prospect of broadcasting being rolled back below 700 MHz much before 2030. Even the likely clearance of the 700 MHz is likely to last into the 2020s, with a number of administrations and broadcast network operators still feeling the pain from the 800 MHz clearance.

In more detail

The study team (which included ex-Ofcom William Webb) evaluated the costs and benefits of the various options for convergence – in so far as data was available. A few problems were identified:

  • They found it difficult to get data on converged viewing vs linear TV viewing…. need better measurement methods
  • The standards that might be used e.g. LTE Broadcast , have not yet defined (work for 3GPP to do)
  • The broadcast-related re-engineering costs are difficult to estimate, given diverse market and conditions across the EU
  • The spectrum yield that might arise from moving to all-Single Frequency Network (SFN) broadcasting is not fully pinned down
  • A period of simulcast would be required, but it isn’t clear where the spare spectrum would come from
  • WSD and PMSE users would see their capacity in UHF reduced – they would need to look elsewhere for additional capacity
  • Pinning down the value of spectrum (in terms of auction price) is difficult and evaluating its wider economic and societal benefit is harder still

The main options considered were around reallocation of sub-700 MHz spectrum from conventional DTT broadcast to some form of mobile-friendly unicast, from 2025 onwards. Making the unicast downlink-only reduces risk of interference to DTT receivers and in home TV distribution systems. The study team assumed that uplink for interactive services would occur in the bands from 700 MHz upwards. The team also assumed that EU member states would have moved to the more efficient DVB-T2 and that SFNs would widely adopted* by the time these options would be introduced, to provide the necessary capacity flexibility.

The technology that would be used for the unicasting is open at this point. LTE-Broadcast is not yet defined, but DVB-T2 could deliver a high level of spectrum efficiency (~5 bits/Hz).

*Qualcomm commissioned a report from ADTI on how low power SFNs could help free sufficient spectrum and hence create flexibility for progress on convergence. 

DSA Global Summit shows African appetite for broadband

The Dynamic Spectrum Alliance, a group backing more flexible, affordable, access to spectrum, just concluded its Global Summitin Accra. The group includes Internet Heavyweights such as Facebook, Google and Microsoft, who are keen to explore ways of extending broadband Internet to the 3 billion+ who currently lack the education, healthcare and economic benefits it can bring. Bridging this digital divide was a central theme of the Summit, building on discussion stimulated by the CEO of Facebook and others at the Mobile World Congress (MWC), back in March 2014. Whilst the challenge at MWC was to operators to make mobile broadband more affordable, the challenge at the DSA Summit was to regulators (and industry) to enable low cost coverage solutions (especially using TV white spaces) which in turn would allow connectivity costs to be lowered to the point of affordability even in rural areas. The figure of $2/month emerged as the target level, which would allow rural communities to bootstrap their economic development.

Former Ofcom Spectrum Chief Prof H Nwana, is the new Chief Executive of the DSA, who guided the event programme and discussion towards its successful conclusion. The programme was sufficiently engaging to keep a good attendance right through to the end, in spite of the somewhat higher frequencies (UV) available in abundance to those reclining on the nearby Labadi Beach.

An African poverb was introduced 'If you want to go further, then travel together'. This seemed an appropriate encouragement for regulators and industry who want to make DSA a reality in their country. Delegates heard about numerous and diverse partnerships around the world, which have delivered real benefits.

News from technology vendors on their plans for silicon, and hence more compact and affordable devices, was encouraging for regulators and operators who would like to see DSA-based networks able to operate commercially - standealone or with part subsidy. The fact that TV white spaces (TVWS) is now a commercial reality in the US and imminently in the UK, has encouraged vendors to invest in their product development - both in radios and database services.

The event in Accra was co-hosted by the Ghanaian regulator (NCA) and there were regulators as well as academic and industry representatives from a number of other African countries - as well as from Europea, America and Asia. The host regulator seemed proud to announce the latest TV white spaces pilot, in Ghana, backed by Microsoft, Facebook and SpectraWireless (an African company with a strong interest in extending Internet connectivity across this continent). Delegates at the summit enjoyed Wi-Fi service (called Djungle), whose backhaul used white space links which have just been installed.

Costs of backhaul are still a big issue for rural areas, but Don Means from Gigabit Libraries presented groundbreaking work by his organisation on using TVWS technology to distribute connectivity around public buildings such as libraries.This is helping libraries to reinvent themselves at the heart of local communities.

Representatives from the ITU and GSMA emphasised the need for interference protection to underpin mobile broadband investments and seemed not quite so keen on expanding licence exempt access.

Related to this topic was a discussion of whether DSA frameworks should offer white space channel reservations (sometimes referred to as a protected mode or safe harbour), to provide certainty to those (small or large operators) wishing to deploy wide area networks using this technology. Effectively, the US and UK (draft) regulatory frameworks already offer a protected mode, for professional PMSE applications (wireless microphones etc.).

There was a debate about whether exclusivity was the best way of 'guaranteeing' spectrum access, given the success of licence exempt Wi-Fi and increasing sophisticated use of MIMO etc to create separate channels and avoid the waste of capacity that can accompany exclusivity.

Many supported the use of DSA to enable an increase in licence-exempt allocation, especially below 1 GHz - with the clear importance of this spectrum region for filling gaps in broadband coverage - large and small. Against a backdrop of reductions in UHF capacity allocated to broadcasting, there were strong arguments for creating a licence exempt reserve - effectively a minimum capacity that would be available everywhere for Super Wi-Fi (using the new IEEE 802.11af standard, which binds TV white spaces into the future of Wi-Fi.

Larkhill was delighted to meet with representatives from African regulators, ISPs and academics. It seems clear to us that Africa's role in shaping spectrum policy is continuing its ascendancy. Although DSA may have seemed a somewhat dry and complex technical subject, this Summit has assisted the raising of awareness of its great potential to help bring Internet to the 70% of Africans who live outside urban centres - without displacing existing wireless services , including TV broadcasting.

It was encouraging to see a wide range of TVWS pilots/trials underway in different African countries. Microsoft and Google have helped local players to get the networks up and running in a number of cases. The Centre for White Space Communications (University of Strathclyde) has brought its unique rural connection expertise to bear in helping with many of these roll-outs, under the Project Mawingu (Cloud) umbrella.

The various pilots use diverse configurations, but the common factors include long link lengths, some non-line of sight requirements and generally abundant white space channels. It is easy to see why the TV white spaces technology is attracting so much attention in Africa.

At the end of July 2014, the Glasgow 2014 Commonwealth Games will bring many of the interested African countries to a city which itself is playing host to a significant TV white space deployment (as part of Ofcom's UK TVWS pilot) and is the home of the Centre for White Space Communications. It should be a great opportunity to continue the discussions.

Watch these spaces....


Further reading:

African Telecom and IT

Telecom TV





Over the two days, delegates were

First wide area trial of LTE Broadcast in 700 MHz

Nokia Networks, the new handset-free business, has announced a landmark trial in Munich. The company is using a white space channel in the 700 MHz band (which is still allocated to DTT in Europe) to show how TV content could be distributed using LTE Broadcast technology. It is using a single frequency network with 4 base stations sites, covering an area of 200 square kilometers.

The base stations are running evolved Multimedia Broadcast/Multicast Service (eMBMS) software.

Nokia seems to believe that LTE Broadcast technology could be used to complement or even substitute DTT technology, in some cases.

More details in this article.




French economist flags up the importance of dynamic spectrum access

A leading French economist, Professor Joelle Toledano, has just published a report which points to the importance of progressive spectrum management to innovation and economic growth. The report which was commissioned by the French Finance Ministry, in the middle of 2013, draws on interviews with major players and innovators from Europe and the US. It highlights the leading role played by the US and the UK in getting dynamic spectrum access started and points to the importance of licence exemption as a tool for accelerating innovation. The report is written in French, but an executive summary in English can be found here.

It will be interesting to see what actions French policymakers take in response to Professor Toledano's recommendations. France is very influential in developing European spectrum policy and contributes significant resources to working groups in CEPT and ETSI. So its Government's actions will be studied closely.

Japan's NICT comes to UK for White Spaces trial success

The NICT, a Japanese research institute which has developed TV white spaces (TVWS) technology, has been participating in Ofcom's UK white spaces pilot. It has brought both radios and its own geolocation database.

This gives NICT an opportunity to understand how the TVWS technology can work within the draft UK regulatory framework - by which white space devices obtain access to spectrum via an Ofcom-qualified geolocation database. NICT reports that it has achieved a link performance of up to 40 Mbps over a distance of 3.7 km - within a 4 Watt transmission power limit. The link spans the distance between Denmark Hill and Guys campus locations of Kings College London, with which NICT has been collaborating. Two radio technologies have been deployed in the trial:

  • 802.11af (the variant of Wi-Fi designed to exploit the range offered by TV white spaces)
  • LTE in a 20 MHz channel, comprising 3 contiguous white space UHF channels - supporting a data rate of 40 Mbps

More details in this press release from NICT.


Might the FCC be preparing to reserve UHF spectrum for unlicensed use?

A recent blog post by FCC Commission Chair Tom Wheeler has indicated that a draft rule & order has been circulated, laying out plans for an incentive auction in the 600 MHz band, currently being used by broadcasters. The proposals are thought to include measures to secure capacity for unlicensed (licence-exempt) use - including Channel 37 (currently kept clear for radio astronomy and medical applications). There is potential to make guard bands and duplex gaps available, in the event of broadcasters releasing the spectrum through the much discussed incentive auctions. Any measures to reserve licence exempt access would be helpful to the emerging white spaces technology market and helpful for increasing Wi-Fi coverage capability (through the recently published 802.11af variant).

It still remains to be seen exactly what will be offered in any auction, and which broadcasters would seek to avail themselves of any disposal options.

[Source: Article]

New UK Digital Industries minister should be helpful for Ofcom's DSA plans

In the recent shuffle of UK Government ministers, Ed Vaizey, the Minister for Broadband, not only survived but had its portfolio extended to a broad 'Digital Industries' remit. Ed Vaizey's support for progressive policymaking on Spectrum has been helpful for Ofcom's push to introduce Dynamic Spectrum Access (initially in the TV white spaces). See this article.

Ed attended the launch of the Centre for White Space Communications, in the University of Strathclyde, back in January 2013. His keynote speech then was very supportive to the concept of harvesting unused spectrum capacity through DSA, to help rural communities enjoy better broadband, for example. Nor was this to be at the expense of existing UHF services - he has been a strong supporter of Digital Terrestrial Broadcasting and its continuing technological journey.

Ofcom has devoted considerable resource to translating the Dynamic Spectrum Access vision into workable regulations for the UK /European UHF contexta and is also looking closely at other opportunities to apply the new spectrum sharing technology. The 3.5 GHz band is one such, with the advantage that it is also under considering, for DSA, in the US - and therefore offers potential harmonisation benefits. With its UK TV white spaces pilot now under way, Ofcom is in the home straight for introducing the regulations to enable the licence-exempt access for which the industry has been waiting.

In his new role, we are confident that Ed will continue to advocate more efficient and flexible spectrum usage as a vital underpinning for the future of the UK's Digital Industries.

Ofcom reveals breadth and depth of UK TV white spaces pilots

The UK is working hard to share spectrum more effectively - by applying new dynamic sharing technology to tap unused TV white spaces, in the first instance. The TV white spaces are gaps left in the UHF TV broadcast bands (the frequency range is 470 to 790 MHz), to prevent high power TV broadcasts from interfering with each other. These gaps have already been used intensively within theatres, studios and other venues, for wireless microphones and other programme-making devices (referred to as PMSE applications) - however much capacity remains untapped across the UK.

Last month BBC Newsnight featured news of how white space technology could help rural broadband on the Isle of Wight and life in future cities - beginning in Glasgow.

Now, Ofcom has just released details of the white spaces applications across the UK, being carried out under the umbrella of its UK TV White Spaces Pilot. The applications range from allowing Orkney ferry users to stay connected to the Internet, to enabling London Zoo's meerkats to start their own live Youtube channel. Broadband connections as well as 'Internet of Things' applications feature in the deployments.

Larkhill is pleased to be closely connected with the Glasgow white spaces pilot - working (on behalf of Microsoft) with 6Harmonics, the Centre for White Space Communications (University of Strathclyde), Mediatek, Sky, Spectrum Bridge, and the Scottish Government. The Glasgow Pilot builds on experience from an earlier trial of TV white spaces in improving broadband on the Isle of Bute. 

The broad geographic spread of diverse applications illustrates the growing UK interest this technology - following action by US regulators to allow licence exempt use of the technology, back in 2010. Regulators in Africa and Asia are now following UK and US regulatory developments in this field.

The Dynamic Spectrum Alliance (whose members include Facebook, Google and Microsoft) has been assisting with the development of pilot white space deployments across Africa and Asia (where Singapore is particularly well advanced in its preparations to allow commercial applications of the white spaces technology). In Europe, the CEPT and ETSI have both laid important foundations for enabling this technology to be used in a harmonised way across the single market.

Wi-Fi is being adapted to take advantage of the improved coverage that white spaces enables - indoors and outside. The new IEEE 802.11af standard builds on the Gigabit performance offered by 802.11ac, by adding capacity in the TV white spaces bands. This is achieved through the new dynamic spectrum access technology, in which devices consult geolocation databases to determine which UHF channels they can use and with what power limit. So we can look forward to Wi-Fi access points which offer three bands: TV whitespaces as well as 2.4 GHz and 5 GHz.

Ofcom expects to complete its process for allowing licence exempt use of this spectrum (and hence commercialisation), early in the new year.

Larkhill has been following the process since around 2006 from early days in the US through to today - so we are well placed to help organisations that wish to understand the potential impact of this exciting new technology.

Positive experience of applying white spaces in a US City

The following video clip contains interviews on the experience of using white spaces technology in the city of Wilmington, North Carolina, USA. The interviewees, from the city authority, point to considerable savings in delivering some of the advances they needed in 'reinventing' the city to be more attractive to investment in new jobs. Here's the clip - featuring interviews conducted by Guy Daniels from Telecom TV.

The race for mobile capacity - small and dynamic is beautiful

The World WiFi and Small Cell Summit , 28th-29th October 2014 in Barcelona, attracted industry representatives from across the globe, focussing on technology advances that will enable operators to service the growing demands for mobile connectivity.

There were two strands to the proceedings – Wi-Fi and Small Cells. Originally there had also been plans for a Cloud Radio Access Network (CRAN) strand, but it had been contracted and interwoven with the other strands.

Given that many of the target audience were service providers, it was not surprising that there was much in common between the Wi-Fi and Small Cell strands. The emphasis on needing to ‘densify’ coverage was shared – with Wi-Fi as the ideal for maximising capacity, given the high degree of spectrum use. Coverage in buildings was also an issue, where again Wi-Fi has much to offer. There is an increasing interest in managing Wi-Fi and integrating it into service platforms, alongside licensed network technologies. Other themes included:

  • Centralisation of base station functionality – whether for small cells or macro cells, using either fibre or high capacity wireless front haul technologies to link antennas to a central hub. The central hub could be cloud-based ultimately with functionality being provided scalably via software. This offers operating cost savings, yields more efficient coverage and is more flexible to adapt to rapidly evolving market requirements
  • Aggregration of bands to increase throughtput - even across traditional licenced /licence-exempt boundaries. Thus Wi-Fi cellular hybrids start to appear in the picture, with integration in the service platform rather than in end-user client devices.

Larkhill’s contribution to the event was a presentation on the opportunity of using dynamic spectrum access technology to use spectrum more efficiently, with TV white spaces providing a global opportunity to create a really powerful extension to Wi-Fi. We also highlighted the need to address resiliency, ad-hoc flexibility and coverage – as well as the growing capacity requirements for mobile access networks. You can see a summary of our presentation here.


TV White Spaces in your new TV receiver ?

With TV white spaces having been given the green light to become a real commercial proposition in the UK this year - with many other countries at different stages of their regulatory journey, the technology may soon start to be incorporated in a range of consumer as well as professional devices.

Our founder, Andrew Stirling, was quoted in a recent article in Videonet by digital broadcasting columnist Barry Flynn, discussing the prospects for TV white spaces coming to a TV set near you. After all the UHF bands which are home to TV white spaces are already well catered for in terrestrial TV receivers and antenna systems.

UK gives the green light to TV white spaces and opens door to DSA

Ofcom has just announced that it is proceeding with the opening of licence exempt access to the TV white spaces.This is a landmark decision, opening the door to a new era in more flexible access to spectrum. It complements the forms of spectrum access, largely licensed, by exploiting new dynamic spectrum access (DSA) technology

DSA allows unused spectrum capacity to be identified e.g. through a national database of available channels in each area. This means that devices which need to form a link can do so without disrupting established services and applications. In the case of TV white spaces, the established uses include Digital Terrestrial Television (the primary spectrum user) and wireless microphones (and related equipment, referred to as 'Programme Making and Special Events' (PMSE) devices)

DSA enables spectrum to be used more efficiently, by allowing opportunistic access to unused pockets of capacity - e.g. in rural areas. Users or communities can purchase their own equipment to take advantage of this spectrum - e.g. to fill holes in broadband coverage, complementing service availability from national operators, for example.

After working with industry over a number of years and learning from the FCC experience, Ofcom developed a frameowrk for using the TV white spaces. It has been conducting a Pilot of this framework since 2013, in which a number of projects from across the UK have been taking part. Scotland has seen a number of interesting deployments - starting with the first UK TVWS trial network , back in 2011, then with the University of Strathclyde's city centre campus deployment (Glasgow) and more recently the pilot network aimed at bringing Wi-Fi to Orkney ferries. Ofcom's release lists these together with an appealing zoo animal watch application provided by Google and a flood detection network in Oxford - with LoveHz and Nominet cooperating.



What's the experience of white space users

The following video clip contains interviews on the experience of using white spaces technology in the city of Wilmington, North Carolina, USA. The interviewees, from the city authority, point to considerable savings in delivering some of the advances they needed in 'reinventing' the city to be more attractive to investment in new jobs. Here's the clip - featuring interviews conducted by Guy Daniels from Telecom TV.

White spaces made easy - thanks to DSA Model Rules

Members of Regulatory Affairs group of the Dynamic Spectrum Alliance (DSA) have been putting their heads together to review regulatory practice across the world, on access to the TV white spaces and have assembled a Model set of rules. Most of the development work on regulations has been undertaken by the FCC and Ofcom (UK), working with industry.

The intention is to help administrations which have not yet investigated introduction of TV white spaces technology to get up the learning curve faster. The documents provided on the DSA website include:

  1. The Model Rules backgrounder introduces the significance of access to the TV white spaces and the key components of the sharing mechanism designed to protect existing users of the band, namely terrestrial TV viewers and wireless microphone users
  2. Suggested Technical Rules and Regulations for the Use of Television White Spaces

  3. Frequently Asked Questions 

The model rules are based around the use of geolocation databases, with white space devices reporting their positioning in order to determine what spectrum is available to use. They include the concept of master and client devices, where the master device acts an intermediary between client devices and databases. Clients need only consult their local master device in order to determine which channels are safe to use.

White spaces ride to the rescue of rural communities - in UK and Africa

The potential of TV white space spectrum to assist with improving broadband for rural communities is rapidly gaining wider recognition.

In the UK, as regulator Ofcom proceeds with a UK pilot of its proposed TV white spaces regulation, the BBC has been looking at what the opening up of this unused spectrum could mean for rural communities.

The TV white spaces are gaps left between frequencies used for terrestrial television broadcasting in the frequency range 470-790 MHz. Prior to the emergence of dynamic spectrum sharing technology, this spare capacity was considered too fragmented and sensitive for mass market applications. Its use has hitherto been confined to wireless microphones and other programme-making/events equipments - but event these only use the space capacity in certain times and places - not often in rural areas afflicted with poor broadband. Ofcom has committed to opening up this spectrum by early 2015.

A recent BBC news report covered developments on the Isle of Wight and in Scotland, to try to project what this technology could bring to help solved the urban-rural broadband gap in the years to come. The Isle of Wight segment covered both rural broadband and application to life boat communications - areas which have proved challenging for commercial deployments in the past.[Those in the UK can enjoy this BBC TV Newsnight piece - see 38:55 mins from the start]

Separately, BBC Radio 4 carried an interview on its Farming Today programme (28th August) (8 mins 15 secs from start) with white spaces pioneer, Malcolm Brew , from the Centre for White Space Communications at University of Strathclyde. Malcolm who is busy deploying white spaces technology to bring Internet connections to rural African communities, talked about life has been transformed life for the community on Bute through its white spaces pilot project - letting farmers register their livestock and pubs order beer online.

At the same time, Microsoft has announced that a major new white spaces pilot project has commenced in Namibia, in South Africa, covering the largest land area yet attempted with the technology (9,424 km²). There are 28 schools now enjoying Internet access under the scheme . The partners behind this included Microsoft, MyDigitalBridge and radio suppliers Adaptrum - with funding from the Millennium Challenge Corporation and Millennium Challenge Account (MCA)-Namibia.