NR-U/Wi-Fi Coexistence in 5/6 GHz bands

Unlicensed Spectrum Growth: 5 GHz 5 GHz Band (United States, Current) UNII-1 5250 MHz 5350 5470 5725 5825 5150 802.11 channels UNII-2a UNII-2b UNII-2c UNII-3 UNII-4 5925 MHz Available Channels Not Yet Available And we have more work to do in 5 GHz for Wi-Fi. As you can see in this band plan, we opened a new channel for 802.11ac at the bottom of the band, to complement the channel at the top of the band that is already heavily used. But there remain a number of restrictions on Wi-Fi use in 5250-5350 MHz and 5470-5725 MHz, and new bandwidth is possible in the middle and top of 5 GHz. We are currently focusing our efforts on: Firstly, helping other regulators understand the recent FCC action in 5.1 GHz, in order to achieve a similar result globallly; and, Secondly, turning our attention to 5.9 GHz, where Wi-Fi will hopefully share the band with transportation services. We are working to determine how this can best be achieved. FCC is set to propose an expansion of unlicensed access into the 5.9 GHz band The entire 5 GHz band is being considered for enhanced global access (WRC-19) Coexistence is crucial: 802.11ac/ax/be, LAA, NR-U, DSRC, and C-V2X may all share this spectrum

Unlicensed Spectrum Growth: 6 GHz 5925 MHz 6425 MHz 7125 MHz UNII-5 UNII-6 UNII-7 UNII-8 40 80 160 20 59 x 20 MHz 29 x 40 MHz 14 x 80 MHz 7 x 160 MHz 5925 MHz – 6425 MHz Under discussion: US 1.2 GHz EU 500 MHz 40 80 160 20 24 x 20 MHz 12 x 40 MHz 6 x 80 MHz 3 x 160 MHz Both US and Europe are considering to open significant license-exempt bandwidth in the 6 GHz range 6 GHz is critical to expand the Gbps broadband access to the residential environments IEEE and 3GPP technology will populate this band, both expected to operate in the context of: i) existing incumbent users and ii) equal air time access probability Coexistence is as critical in 6 GHz as in the 5 GHz

Wi-Fi Remains a Broadband Workhorse DRAFT FOR DISCUSSION Wi-Fi Remains a Broadband Workhorse Source: Cisco VNI Global IP Traffic Forecast, 2017-2022 By 2022: Wi-Fi networks will carry more than 50% of total global IP traffic and nearly 80% of total global IP wireless traffic Wi-Fi networks will remain the workhorse of personal wireless access technology for the foreseeable future.

Cable WI-FI Footprint* DRAFT FOR DISCUSSION Sample Operators Wi-Fi APs Altice USA (NY Tri-State) > 2,000,000 Comcast (US) > 19,000,000 Liberty Global (Europe) 12,000,000 Shaw (Western Canada) > 100,000 Charter Communications (US) > 250,000 Total Sample (Member) Public APs (2018) > 33.35 M Estimated Total (Public & Private) Member APs (2018) ~135 M CableLabs members: Collectively serve more than 135 Million high-speed data subscribers Wi-Fi supports personal, small, business communications, entertainment, IoT. *Source: Company websites, CableLabs member data No wireless access technology intended for the unlicensed spectra (5/6 GHz) could be defined without considering Wi-Fi. While these APs are mainly 802.11ac based, they are in course of transitioning to 802.11ax (5/6 GHz) by 2025.

LTE Offload on Wi-Fi networks Mobile Traffic Offloaded to Wi-Fi (%) Wi-Fi Offload provides over 3/4th of total data consumed through mobile devices. A sub-optimal LAA LTE/NR coexistence with Wi-Fi will degrade the mobile to Wi-Fi offloading.

3GPP – IEEE Communications. Lessons Learned. Goodwill between the two SDOs during the LTE LAA workshop in 2015*: “... IEEE: would like to see a collaboration to be established between the coexistence group of IEEE 802 and RAN5…” “…RAN Chair: 3GPP is totally open to such interaction and collaboration…” LS exchanges The LS exchanged between IEEE and 3GPP, on LAA LTE and NR-U, failed to address multiple points of contention. Certification/Test Programs RAN4 LTE LAA coexistence testing specifications remained optional. WFA LTE LAA coexistence testing specifications didn’t get a cross industry (mobile-fixed) traction. Agreement on the LTE LAA fairness criterion for coexistence (5 GHz) However no such criterion was agreed on for the 6 GHz band. Should 3GPP and IEEE continue the unlicensed bands standard developments, without a minimal synchronization: The Wi-Fi (802.11ac/ax) and LTE LAA/NR-U equipment rolled out in the field may mutually degrade their end-user experience performance. As the last resort, this may require the intervention of the regulatory bodies. * 3GPP LAA-1509, “Report of 3GPP RAN workshop on Licensed-Assisted Access (LAA)”, Beijing, 08/29/2015

LTE LAA: The Unique Energy Detection (ED) Wi-Fi Energy Detection (ED) Threshold -62 dBm Wi-Fi is dominant* over the air interface LTE Energy Detection (ED) Threshold -72 dBm LTE is dominant over* the air interface Wi-Fi Preamble Detection (PD) Threshold -82 dBm The actual 3GPP NR-U specifications trend may drive to the same type of unique ED concept. * As a result of LBT when the other access technology is detected

The ED Threshold Coexistence Challenge (1/2) 5 GHz public outdoor Wi-Fi Network* - 17,410 APs (one of the largest US East Coast Cities) 5 GHz subway Wi-Fi network* - 3,761 APs (one of the largest European capitals) -72 dBm -72 dBm \ RSSI Distribution (AP UL Rx RSSI dBm) RSSI CDF Distribution (AP UL Rx RSSI dBm) The indoor subway traffic* peak (8am) occurs @ -75dBm The RSSI CDF reflects the local geography (>250 subway stations) The outdoor UL traffic* peak occurs @ -87dBm A unique ED threshold can’t address multiple types of coexistent traffic (e.g. outdoor, office, subway etc.) An optimal coexistence scenario would require a RSSI distribution agnostic solution * Data acquired by CableLabs members

The ED Threshold Coexistence Challenge (2/2) An ED threshold at -72 dBm would block: 92% of the outdoor Wi-Fi traffic* 54% of the subway Wi-Fi traffic* The unique ED doesn’t support an optimal coexistence A common preamble (e.g. 802.11) provides: A fair air interface access probability It is environment agnostic Support for hidden node detection by providing a dynamic PD (e.g. 802.11ax case) PD could be detected in the presence of elevated noise (unlike ED). PD provides potential power savings, since the transmission duration is known \ * Data acquired by CableLabs members

Way Forward Implement the 802.11 preamble on NR-U (5/6 GHz) Specify a new fairness criterion for 6 GHz Without a jointly agreed 6 GHz fairness criterion (e.g. equal air time access), the 6 GHz NR-U specs development would remain challenging. Setup a small joint tiger team representing both SDOs to address the challenges impacting the existing and the future unlicensed bands.