AI 1.16 RLAN at 5GHz

Agenda item 1.16

1.16 to consider issues related to wireless access systems, including radio local area networks (WAS/RLAN), in the frequency bands between 5 150 MHz and 5 925 MHz, and take the appropriate regulatory actions, including additional spectrum allocations to the mobile service, in accordance with Resolution 239 (WRC-15);

Resolution 239 (WRC-15) Studies concerning Wireless Access Systems including radio local area networks in the frequency bands between 5 150 MHz and 5 925 MHz

 

 

Background

RLANs have proven to be a success at providing affordable and ubiquitous broadband wireless access to the Internet in conjunction with other fixed and mobile networks. These were introduced by some administrations in the 2.4 GHz band and subsequently expanded into some of the 5 GHz frequency bands. Traffic on broadband Wireless Access Systems (WAS) has increased. RLANs, specifically Wi-Fi devices, now carry approximately half of all global Internet Protocol (IP) traffic. In fact, mobile carriers have increased their reliance on Wi-Fi offload, voice-over-Wi-Fi, and similar technologies. The technology has evolved to meet increasing performance demands. The use of wider bandwidth channels in order to support high data rates creates a need for additional spectrum.

The ITU Radio Regulations (RR) require the use of the bands 5 150-5 350 MHz and 5 470-5 725 MHz by stations in the mobile, except aeronautical mobile, service to be in accordance with Resolution 229 (Rev.WRC-12).

Since WRC-03, the demand for mobile broadband applications especially for WAS/RLANs has been growing rapidly. Resolution 239 (WRC-15) states "that the results of ITU-R studies indicate that the minimum spectrum need for WAS/RLAN in the 5 GHz frequency range in the year 2018 is estimated at 880 MHz; this figure includes 455-580 MHz already utilized by non-IMT mobile broadband applications operating within the 5 GHz range resulting in 300-425 MHz additional spectrum being required".

One issue WRC-15 examined was the possibility of additional global allocations to the mobile service (MS) for terrestrial mobile broadband applications. WRC-15 looked at whether additional allocations in the 5 GHz range could be made in order to facilitate contiguous spectrum for WAS/RLAN. This would enable the use of wider channel bandwidths. Wider channel bandwidths would allow higher data throughput. ITU-R study groups performed studies before WRC-15. These showed that if the WAS/RLAN mitigation measures were limited to the regulatory provisions of Resolution 229 (Rev.WRC-12) sharing would not be possible. The mitigation measures would be insufficient to ensure protection of certain radar types in this frequency band. Sharing between WAS/RLAN and the Earth exploration-satellite service (EESS) (active) systems in the frequency band 5 350 to 5 470 MHz would also not be feasible. For these cases, sharing may only be feasible if additional WAS/RLAN mitigation measures are implemented. However, the Report of the CPM to WRC-15 stated that no agreement was reached on the applicability of any additional WAS/RLAN mitigation techniques.

No agreement was reached on the conclusions of the studies for the frequency band 5 725-5 850 MHz. As such, WRC-15 concluded no change (NOC) for these frequency bands and established a WRC-19 agenda item to continue the work.

Resolution 239 (WRC-15), calls for ITU-R to:

– study WAS/RLAN technical characteristics and operational requirements in the 5 GHz frequency range;

– perform sharing and compatibility studies between WAS/RLAN applications and incumbent services in the frequency bands 5 150-5 350 MHz, 5 350-5 470 MHz, 5 725-5 850 MHz and 5 850-5 925 MHz while ensuring the protection of incumbent services including their current and planned use;

– consider enabling outdoor WAS/RLAN operations in the frequency band 5 150-5 350 MHz;

– consider potential MS allocations to accommodate WAS/RLAN operations in the 5 350-5 470 MHz and 5 725-5 850 MHz frequency bands; and

– identify potential WAS/RLAN use in 5 850-5 925 MHz frequency band.

Summary/Methods to address the agenda item

The frequency bands which ITU studies considered are 5 150-5 250 MHz, 5 250-5 350 MHz, 5 350-5 470 MHz, 5 725-5 850 MHz and 5 850-5 925 MHz. The methods related to the bands are denoted by the letters A, B, C, D, and E, respectively. When multiple methods are proposed for a particular frequency band, the methods are expressed by the associated letter and a numerical suffix (Method A1, Method A2, etc.); when only one method is proposed for a particular frequency band, the method is expressed by the associated letter (B, C, etc.).

For the 5 150-5 250 MHz frequency band, six methods (incl. NOC) are proposed (A1, A2, A3, A4, A5 and A6);

for the 5 250-5 350 MHz and for the 5 350-5 470 MHz frequency bands, only one method, that is No Change (NOC), is proposed (B and C respectively);

for the 5 725-5 850 MHz frequency band, three methods (incl. NOC) are proposed (D1, D2 and D3);

for the 5 850-5 925 MHz frequency band only one method, that is No Change (NOC), is proposed (E).

 

For bands B, C and E only a No Change method is proposed. The reasons are summarised as follows;

 

 

Frequency band 5 250-5 350 MHz (Band B)

The Earth Exploration Satellite Service (EESS) (active) and the Radiolocation Service (RLS) are allocated in this band. There are a number of altimeters and scatterometer sensors currently operating and planned to operate in the future in this band.

The current WAS/RLAN operating parameters are specified in Resolution 229 (Rev.WRC-12). Since the adoption of Resolution 229 at WRC-03, millions of WAS/RLAN (e.g., Wi-Fi) devices have been deployed in the 5 250-5 350 MHz frequency band.

In preparation for WRC-19, studies have shown that changing operating conditions in the 5 250-5 350 MHz frequency band, would not ensure protection of the radiolocation service and EESS (active) sensors. Furthermore, the current WAS/RLAN operating conditions in the 5 250-5 350 MHz frequency band are sufficient for the operating needs of WAS/RLAN users.

 

Frequency band 5 350-5 470 MHz (Band C)

The frequency band 5 350-5 470 MHz, or parts thereof, is allocated to the EESS, RLS, ARNS, SRS and RNS.

Previous studies show that sharing between with the EESS (active) systems in the 5 350-5 470 MHz frequency band would not be feasible unless additional RLAN mitigation measures are implemented. The latest study results show that there are no feasible mitigation techniques to ensure compatibility with EESS.

Study results show that there are no feasible mitigation techniques to facilitate sharing between RLAN and the different radar systems in the 5 350-5 470 MHz frequency band.

 

Frequency band 5 850-5 925 MHz (Band E)

The frequency band 5 850-5 925 MHz is allocated to the Fixed Service and Fixed Satellite Service (Earth to space) on a primary basis. The Mobile Service is co-primary in the band also. Various mobile applications, including ITS, are already in operation  Studies show that sharing of RLAN with these mobile applications and reception of uplinks at space stations would be difficult.

 

 

 

CEPT position on the bands B, C and E

CEPT supports the three cases of No change. In the 5250-5350 MHz band, CEPT notes that the current studies have shown difficulties sin achieving co-existence with incumbent services. Sharing between RLAN and the other services in the band 5350-5470MHz is not feasible with the current regulatory provisions in the Resolution 229. There are no feasible additional mitigation techniques available to facilitate sharing between RLAN and incumbent services in the band 5350-5470MHz. In the band 5850-5925MHz, CEPT notes that the current studies have shown difficulties in achieving co-existence between RLANs operating outdoor up to 1W with unrestricted use and other incumbent services without imposing any additional constraints on existing services.

Methods to address the agenda item for frequency bands A and D

Frequency band A, 5150-5250MHz

Method A1: No change to the RR

 

Method A2: Revision to Resolution 229 (Rev.WRC-12) to enable outdoor RLAN operations including possible associated conditions for new e.i.r.p. limits

 

Method A3: Revision to Resolution 229 (Rev.WRC-12) to enable outdoor RLAN operations by applying the same conditions of use as defined for the 5 250 5 350 MHz frequency band in resolves 4 of Resolution 229 (Rev.WRC-12)

 

Method A4: Revisions to Resolution 229 (Rev.WRC-12) to facilitate limited RLAN outdoor operation and RLAN in-vehicle (cars and trains) usage operation with associated e.i.r.p. levels

Outdoor RLAN use would be limited to a maximum e.i.r.p. of 200 mW, in-car use to e.i.r.p. levels up to 40 mW and in-train use up to 200 mW e.i.r.p..

CEPT supports this method A4.

 

Method A5: Revisions to Resolution 229 (Rev.WRC-12) to enable in-car use of RLAN operation with e.i.r.p. up to 40 mW

This use would be on condition that the additional propagation loss due to the car hull is at least 15dB.

 

Method A6: Revision to Resolution 229 (Rev.WRC-12) to enable outdoor RLAN operations including associated conditions for new e.i.r.p. limits and out-of-band emission limits

 

Frequency band D, 5 725-5 850 MHz

Method D1: No change to the RR

No changes are proposed to the RR, with the exception of the suppression of Resolution 239 (WRC-15).

CEPT supports Method D1,  No Change.

Method D2: A new Regional primary MS allocation

Allocate the 5 725-5 850 MHz frequency band to the mobile service on a primary basis in some Regions. This regional allocation would be to accommodate WAS/RLAN use restricted to indoor operation with e.i.r.p. limits up to 200 mW. There would be associated mitigation techniques. This method also proposes the revision of Resolution 229 (Rev.WRC-12).

Method D3: Accommodate WAS/RLAN in a new footnote

This method accommodates WAS/RLAN in a new footnote having a mobile primary allocation.