Page 112 - ITU Kaleidoscope 2016

2016 ITU Kaleidoscope Academic Conference

sharing arrangements challenge the conventional types of spectrum utilisation based on whether a license is
management approach to commercial use, especially for needed, on one dimension, and exclusivity in the use of
mobile telecommunications services, that has for long spectrum, on the other.
conceived spectrum as a resource that must be granted on Authorised Shared Access (ASA), a special type of LSA
an exclusive basis [17]. promoted in the European Union, is as a mechanism by
Spectrum sharing can be implemented in one of a range of which a new licensee is granted temporary access to the
variants. For instance, license-exempt bands allow the use of spectrum already assigned to an incumbent under the
a band by any device that complies with a pre-specified prescription that the incumbent does not use it [19]. ASA
technical standard; IEEE 802.11 or Wi-Fi is the best will allow an access seekers to deploy cognitive radio
example of it; or bands shared by licensed and license- techniques that will help it learn about on-the-spot channel
exempt applications and, licensed and light-licensed availability. Such scheme requires bilateral negotiations
commons [19]. between the new licensee and the incumbent. ASA also
allows multiple new licensees access to one or more
In the UK Ofcom has recently released its Spectrum Sharing
Framework [15], which provides mobile and wireless incumbents’ licensed spectrum.
broadband operators with legal room to initiate a request to
gain access to share specific bands. After consultation with
the market, Ofcom summarised the framework in three main Unlicensed
aspects that: 1. state the characteristics of use for License-exempt
prospective users who seek access to shared spectrum; 2. or unlicensed use
advise on the nature and strength of barriers that may limit Collective Use
the future of spectrum sharing; and, 3. discuss the market of Spectrum
and technology regulatory tools and enablers of spectrum Exclusive (CUS)
sharing. Acknowledging that sharing may be detrimental to
a licensee’s interests, Ofcom will need to decide when Shared license-exempt apps
spectrum sharing is economically and technically feasible Dedicated,
and how it represents a beneficial alternative to the status licensed use
quo; otherwise it must maintain the current allocation Shared
untouched. Shared licensed applications
In 2009 New Zealand introduced the Managed Spectrum
Park (MSP), a special type of licensed commons that Authorised Licensed
operates in the 2575-2620 MHz band. With such scheme the Shared Access Shared Access
(LSA)
government has sought to encourage “a flexible, Licensed (ASA)
cooperative, low cost and self-managed approach to
allocation and use” [13] of the spectrum. A MSP allows
access to a number of users – usually operators of
communication services such as wireless broadband- to the
common band on a shared basis and is intended for local and
regional services; applicants to a MSP only seek to cover Figure 1: The spectrum sharing landscape
small geographical areas and do not need or want a
nationwide license. Sharing may take several forms: it may The illustrations provided above indicate that SAs are
be that two or three operators split the available bandwidth attracting attention in different regions. Incorporating of
in an arrangement whose technical aspects need to be sorted spectrum sharing is a process that threatens the
out by private agreements, or it may consist of a conventionally accepted exclusivity of spectrum rights and
geographical split within the licence’s region. acknowledges that technology progress and political
willingness can come together to favour the introduction of
The European Commission has established two models for Dynamic Spectrum Management. Such transition surely is a
sharing frequencies [9]: CUS or Collective Use of slow process and will require the introduction of legislative
Spectrum, and, LSA or Licensed Shared Access. CUS is a and regulatory changes.
license-exempt mode that allows more than one user to use
a spectrum simultaneously and with no requirement for a
license; variants of the commons fit within the CUS
approach. On the other hand, LSA is a scheme which
combines traditional command-and-control management
with an explicit allowance to share spectrum; in a LSA a 5. EFFECTIVENESS OF SPECTRUM ALLOCATION
limited number of parties are licensed to totally or partially AND EFFICIENCY OF SPECTRUM ASSIGNMENT
use the band under sharing rules, which have been approved
by the SA and then included as terms in the license [19]. This section discusses effectiveness and efficiency in the
Figure 1 uses two “dimensions” to classify several model
context of spectrum allocation and spectrum assignment,

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