CONSULTATIVE COMMITTEE II:
RADIOCOMMUNICATIONS
February 23 to 27, 2015
Medellín, Colombia / OEA/Ser.L/XVII.4.2
CCP.II-RADIO/doc.3763/15
12February 2015
Original: English
WRC-15 AGENDA ITEM 10
CONSIDERATIONS RELATING TO THE 5 150 – 5 850 MHZ FREQUENCY RANGE
(Item on the Agenda: 3.1 (SGT5))
(Document submitted by the delegation of Canada)
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Introduction
At the XXIV meeting of PCC.II the United States proposed a future WRC agenda item in Document CCP.II-RADIO/doc. 3624/14, specifically on the implementation of wireless access systems (WAS), including radio local area networks (RLAN), in the band 5350-5 470 MHz band. Canada provides in this present contribution, some possible issues surrounding the implementation of RLANs in this band, as well as in other parts of the 5 GHz band.
The results of ITU-R studies indicate that the minimum requirement for RLAN using the 5 GHz frequency range in the year 2018 is estimated to be 880 MHz. This figure includes 455-580 MHz of spectrum already utilized by non-IMT mobile broadband applications operating in the 5 GHz frequency range resulting in 300-425 MHz of additional spectrum being required. The ranges above are due to some of the frequency bands being identified for RLAN only in some countries.
Currently, RLAN devices utilize the following frequency bands in the 5 GHz range: 5150-5250 MHz, 52505350 MHz, 5470-5725 MHz and 5725-5850 MHz (in some countries).
Figure 1 provides a summary of international allocations in the 5 GHz range. It is noted that this is a simplified representation only; it may not contain all allocations (e.g. allocations by footnotes).
Figure 1
Discussion
5 150-5 250 MHz
WRC-03 allocated the 5 150-5 350 MHz band to the mobile service on a primary basis for the implementation of Wireless Access Systems (WAS), including RLANs. In addition to the mobile service allocation, the 5 150-5 250 MHz band is also allocated to various other radio services on a primary basis including the fixed-satellite service (FSS) (Earth-to-space), this allocation being limited to feeder links of non-geostationary-satellite systems in the mobile-satellite service (MSS). In addition, the band 5 150-5 216 MHz is also allocated to FSS for feeder-links for MSS, and to the radiodetermination-satellite service on a primary basis in Region 2 and in some countries in Region 3, in the space-to-Earth direction. For these satellite services, there are existing and planned operations in both the Earth-to-space and space-to-Earth directions. The band 5 150-5 250 MHz is also allocated to the aeronautical radionavigation service on a primary basis.
As stated in Resolution 229 (Rev. WRC-12), “there is a need to protect existing primary services in the 5 150-5 250 MHz and 5 470-5 725 MHz band”. The Resolution also states “that results of studies in ITU-R indicate that sharing in the band 5 150-5 250 MHz between WAS, including RLANs, and the FSS is feasible under specified conditions”. Pursuant to the Resolution, operation by the mobile service for RLANs in the 5150-5250 MHz band is limited to “indoor use with a maximum mean e.i.r.p[1] of 200 mW and a maximum mean e.i.r.p. density of 10 mW/MHz in any 1 MHz band or equivalently 0.25 mW/25 kHz in any 25 kHz band”. Recently, an Administration has changed its domestic rules to increase the maximum permissible power levels (with elevation angle restrictions) and to allow the outdoor operation of RLANs in the 5 150-5 250 MHz band. From an international perspective, the impact of such change on other allocated primary services is not clear at this time. In particular, Canada is considering whether additional sharing studies between RLANs and incumbent services (including existing and planned systems) in the band need to be carried out at the ITU, which could be facilitated through a WRC-19 agenda item. Discussions are ongoing in Canada on this point, with a view to developing a position.
5 350-5 470 MHz
The band 5 350-5 470 MHz, or parts thereof are allocated to Earth exploration-satellite service (EESS) (active), space research service (SRS) (active), aeronautical radionavigation service (ARNS) and radiolocation service on a primary basis. In terms of EESS, Canada’s first such satellite network, RADARSAT-1, was implemented in the band 5 250-5 350 MHz. In the implementation of subsequent satellite networks, noting that EESS (active) service is allocated throughout the 5 250-5 570 MHz band, Canada decided to implement RADARSAT-2, in the band 5 350-5 450 MHz where no mobile allocation currently exists in order to minimize potential interference. RADARSAT-2, launched in December 2007, offers powerful technical advancements that enhance marine surveillance, ice monitoring, disaster management, environmental monitoring, resource management and mapping in Canada and around the world.
The third-generation of RADARSAT, the RADARSAT Constellation Mission (RCM), a constellation of three similar but more advanced satellites, is the evolution of this EESS Program with the objective of ensuring data continuity, as well as improved operational use and system reliability. RCM will provide complete coverage of Canada's land and oceans offering an average daily revisit, as well as daily access to 95% of the world to Canadian and International users. The mission development began in 2005, with satellite launches planned for 2018. For similar interference related reasons as RADARSAT-2, RCM was designed to be implemented in the band 5 350-5 470 MHz taking into account the absence of a mobile allocation.
An allocation and implementation of mobile services in the band 5 350-5 470 MHz could reduce the capabilities of EESS (active) networks, such as RADARSAT networks, to carry out their mission. In its consideration of WRC-15 agenda item 1.1 and based on the technical studies submitted to the ITU-R, the draft CPM Report in Document CPM15-2/1 only contains one method of “no change” (i.e. no allocation to the mobile service). Specifically, the draft CPM Report concluded that given certain RLAN parameters, “sharing between RLAN and EESS (active) systems in the 5 350-5 470 MHz frequency band would not be feasible. Sharing may only be feasible if additional RLAN mitigation measures are implemented”. While certain mitigation measures were studied over a 3-year period by JTG 4-5-6-7 and concluded to be inappropriate for further consideration, no agreement was reached on the applicability of other additional RLAN mitigation technique. Some additional RLAN mitigation techniques to enable sharing with EESS (active) are being studied by the ITU-R, but no techniques have yet been determined to be effective at this time.
The question of whether or not the ITU-R should invest another study cycle, as suggested by the new agenda item under WRC-19 proposed by the United States, into studying the possible implementation of wireless access systems (WAS), including RLANs in the 5350-5470 MHz band is currently under discussion in Canada, noting that RLAN technologies continue to evolve. Regardless of whether or not this issue is studied further at the ITU, Canada maintains the position that the protection of EESS (active) service must be ensured.
5 725-5 850 MHz
In addition to the currently allocated services including Radiolocation in all Regions and fixed-satellite (Earth-to-space) in Region 1, the 5 725-5 850 MHz band is also designated globally for industrial, scientific and medical (ISM) applications. There are current RLAN deployments in the band 5 725-5 850 in some countries in all three Regions. Regarding the consideration of the 5 725 – 5 850 MHz bands under WRC-15 agenda item 1.1, the draft CPM Report in Document CPM15-2/1 only contains one method of “no change” (i.e. no allocation to the mobile service) for this band. With respect to future WRC agenda items, there have been some discussions in Canada as to whether any regulatory action is needed in this particular band, including a global primary allocation to the mobile services, for consideration by WRC-19. Discussions are ongoing on this point, with a view to developing a Canadian position.
Conclusion
The 5 GHz band has been allocated globally to a number of different services on a primary basis. In addition to considering the United States proposal for a future WRC agenda item for the band 5 350-5 470 MHz, there are also elements of the 5 150-5 250 MHz and 5 750-5 850 MHz bands that may also warrant consideration. Depending on the outcome of discussions, it may be appropriate to develop a proposal for a future agenda item on one or more parts of the 5 GHz band, or to not have a future agenda item for the 5 GHz band at this time, given some of the unresolved issues discussed above. Canada is of the view that these issues would benefit from further consideration by CITEL administrations, to ensure that appropriate discussions take place internationally. The next PCC.II meeting will be a good opportunity to discuss where administrations stand on these issues.
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[1]In the context of this Resolution, “mean e.i.r.p.” refers to the e.i.r.p. during the transmission burst which corresponds to the highest power, if power control is implemented.