Looking at more space for broadband use on Wi-Fi

The highest profile issue for a number of years now in the world of spectrum politics has been mobile wireless broadband. This is not surprising: the players in the drama are big, well-organised and well-known. The concepts and services are familiar to the public: TVs and mobile devices, and the bills paid by users are part of almost everyone’s life. And the drama of big money auctions adds an interesting twist.

But among all of this, the greater growth is now in data traffic over RLAN networks (Wi-Fi). Smartphone and tablet users who pay their own bills understand this well. The appeal of licence-exempt short range spectrum, using an efficient global technical standard is obvious, especially given the relative ubiquity of good fixed broadband connections in most population centres. But a good and appropriate environment is as important for licence-exempt as for any other spectrum.

Broadband everywhere

In the European Union, the aspirations for digital connectivity are expressed through the 'Digital Agenda for Europe'. The European Commission shares the view that Wireless Access Systems/Radio Local Area Network (WAS/RLAN) bands for wireless broadband are emerging as an essential spectrum resource for the provision and uptake of internet-based services. It is therefore necessary to ensure that sufficient spectrum resources are available on a harmonised basis to support a long-term future for new generations of WAS/RLAN technologies, that will provide increasing data capacity and speed.

In September 2013, the European Commission issued a Mandate to us in CEPT to study and identify harmonised compatibility and sharing conditions for Wireless Access Systems including Radio Local Area Networks in the bands 5350-5470 MHz and 5725-5925 MHz ('WAS/RLAN extension bands') for the provision of wireless broadband services.

But there are no empty spaces in these or other frequency ranges; in fact there are a number of existing systems, many of them having recognised primary status and a right to protection. Furthermore, there are other EU policy priority applications used or designated in these ranges, such as the European Earth monitoring programme GMES (Global Monitoring for Environment and Security), now known as Copernicus, and ITS (Intelligent Transport Systems). Therefore the mandate requires that coexistence of WAS/RLANs with other systems in these and in adjacent frequency bands is safeguarded.

The aim is, after the finalisation of the relevant technical and regulatory studies, to extend the spectrum designation for WAS/RLANs as currently provided by EC Decision 2005/513/EC (amended by EC Decision 2007/90/EC), and to enable a future usage of the whole range from 5150-5925 MHz without the requirement for individual authorisations.

The expected development of WAS/RLAN technology and of the relevant standards until 2020, in particular the use of larger channel bandwidths, should also be taken into account.

The spectrum under consideration within the scope of the Mandate is also under discussion in the context of preparations for the World Radiocommunication Conference 2015 (WRC-15) Agenda Item 1.1.

Interest from industry / requirements for additional spectrum

From the RLAN industry point of view, the growing proliferation of Wi-Fi hot spots in private homes as well as the increased importance of publicly accessible Wi-Fi access points in Europe for public institutions (libraries, tourist bodies, etc.) and businesses underlines the value of the WAS/RLAN bands.

In addition to the private use of Wi-Fi, wireless broadband access provided via publicly accessible Wi-Fi access points has to be recognised as an increasingly important internet connectivity infrastructure that is largely complementary to mobile internet services. Given the inherent limitation of coverage, mainly related to power limits and backhaul needs, such WAS/RLAN-based infrastructures can be considered as an essential competitive element in wireless broadband markets to the extent that such services are used in either nomadic or static situations. Therefore, from an industry perspective, there is a demand for higher data rates / higher bandwidths for RLANs.

The majority of RLAN devices in use today are still operated in the 2.4 GHz band (83.5 MHz wide) because the vast majority of commercially available access points in Europe have until recently only been capable of operating there.

While there is already 455 MHz of the 5 GHz band harmonised for WAS/RLANs, the industry sees evidence of an increasing number of consumer devices, including smart phones and tablets, that now have dual-band capability and that large-scale public Wi-Fi networks are a significant driver of 5 GHz use today. In this regard, providing an additional spectrum resource on a shared basis without impacting existing usage could provide additional benefits.

In addition, a new generation of RLAN systems (known as IEEE 802.11ac) will be able to achieve throughput rates sufficient enough to extend high-speed fixed broadband infrastructures wirelessly (of 30 or 100 Mbps or more) to a broad range of consumer devices without reductions in speeds if operating in 80 MHz and/or 160 MHz channels. Today, RLANs with 20 MHz or 40 MHz channels are typically in use.

Incumbent users

Various radio applications are already planned or in use in the proposed bands, 5350-5470 MHz and 5725-5925 MHz. Comprehensive compatibility and sharing studies are required between WAS/RLANs and the following incumbent or planned radio services/applications, and it is a very long list!

  • GMES/Copernicus within 5350-5470 MHz;
  • Radars within 5350-5470 MHz and 5725-5850 MHz;
  • Aeronautical radionavigation services within 5350-5470 MHz;
  • Safety-related ITS (Intelligent Transport Systems) in the band 5875-5905 MHz;
  • Transportation systems, i.e. non-safety ITS in the bands 5855-5875 MHz and 5905-5925 MHz, road toll systems in the bands 5795-5805 MHz and 5805-5815 MHz and other transportation systems used within CEPT for public transport automation (like subways) in the band 5915-5925 MHz;
  • Fixed-Satellite Service (Earth-to-space) in the band 5725-5925 MHz;
  • Broadband Fixed Wireless Access in the band 5725-5875 MHz;
  • Short Range Devices in the band 5725-5875 MHz;
  • Amateur Service within 5725-5850 MHz and Amateur-Satellite Service (space-to-Earth) within 5830-5850 MHz;
  • Broadband Direct-Air-to-Ground Communications (DA2GC) in the band 5855-5875 MHz; and
  • Wireless Industrial Applications (WIA) in the band 5725-5875 MHz.

The possible impact on radio services/applications in the adjacent bands should also be considered.

EU framework, tasks

According to the Mandate, CEPT/ECC should study and identify harmonised compatibility and sharing scenarios for WAS/RLANs in the bands 5350-5470 MHz and 5725-5925 MHz based on the latest generation of WAS/RLAN equipment and define relevant protection parameters and conditions in close cooperation with all concerned stakeholders. The aim is to provide an uninterrupted band from 5150-5925 MHz for WAS/RLANs (775 MHz) on a shared basis and based on a general authorisation.

The relevant developments since the completion of the original studies carried out prior to the World Radiocommunication Conference 2003 for the bands 5150-5350 MHz and 5470-5725 MHz also need to be taken into account.

It should also be assessed whether and how coexistence can be ensured between the future WAS/RLAN usage, as an essential element of the wireless broadband EU priority, and other uses of the 5 GHz band that are currently considered on a shared basis, taking into account studies already on-going in CEPT.

CEPT's Final Report A, which will take into account the results from its public consultation, is expected by March 2015. Final Report B, assessing the need to review and/or reconfirm the compatibility and sharing conditions as provided in CEPT Report A based on the results of WRC-15, is expected by July 2016.

Studies within CEPT/ECC

Based on the working assumption that WAS/RLANs would operate on a co-primary basis under an appropriate mobile allocation in the whole 5150 MHz to 5925 MHz band, and in the light of experience already made on the 5 GHz bands in use, the compatibility and sharing conditions should in particular identify the technical parameters that would be needed to ensure consistent harmonised conditions and requirements for WAS/RLANs operating on a shared basis.

These requirements should also take into account the regulatory and enforcement context of a general authorisation and the protection requirements of the primary radio services to which the proposed WAS/RLAN extension bands have already been allocated. In this context also the bands adjacent to them are relevant, as we have learnt from experience.

The parts of the 5 GHz range that are currently used in the EU for WAS/RLAN systems are subject to a variety of usage conditions which reflect the results of previous coexistence studies. The experiences, made during the last few years with regard to coexistence between WAS/RLANs and other radio applications in the bands 5150-5350 MHz and 5470-5725 MHz will be taken into account, such as: problems with some specialist RLAN users not complying with the required technical conditions. ECC Report 192 on 'The current status of DFS (Dynamic Frequency Selection) in the 5 GHz frequency range' has recently been adopted and published. This Report was intended to keep the collected information, and study further in detail the issue of WAS/RLANs 5 GHz interference to meteorological radars.

The ECC is carrying out compatibility and sharing studies between WAS/RLANs and the incumbent radio applications as shown in the list above. Furthermore, we are also considering regulatory aspects by taking into account the working assumption that WAS/RLANs would operate on a co-primary basis under an appropriate mobile allocation in the whole 5150 MHz to 5925 MHz band and based on a general authorisation. As far as Agenda Item 1.1 of WRC-15 is concerned, the studies are carried out in close cooperation with the preparatory work for this Conference.

We have just delivered an Interim Report to the European Commission, providing a description of work undertaken and interim results under tasks (1) and (2) of the Mandate. However, much work is still to be done as the story of broadband on Wi-Fi unfolds and the scene is set for a broadening broadband narrative.

Thomas Weilacher
Chairman of ECC Working Group Frequency Management

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