doc.: IEEE 802.11-11/1238r0

Submission

September 2011

Rolf de Vegt, QualcommSlide 1

Channelization and Bandwidth Modes for 802.11ah Date: 2011-9-18

Name Affiliations Address Phone email Rolf de Vegt Qualcomm, Inc 3105 Kifer Road, Santa Clara,

CA 4085339545 rolfv@qca.qualcomm.com

Authors:

doc.: IEEE 802.11-11/1238r0

Submission

Abstract• In this document we propose the transmission bandwidths and

channelization for 802.11ah– Transmission bandwidths (BW) refer to the channel widths (or BW

modes) for which the 802.11ah PHY should provide support• Impacts the actual clause on 802.11ah PHY specification

– Channelization refers to the process of breaking down the available spectrum in different regions into ‘channels’• Mainly impacts sections analogous to Annex J of Std-802.11-2007

Slide 2 Rolf de Vegt, Qualcomm

doc.: IEEE 802.11-11/1238r0

Submission

Sub 1GHz Spectrum Availability in Key Geographies

Slide 3

902 928 MHz

917 923.5

929.7

779 787 863 868.6

8 MHz 5.6 MHz 26 MHz

6.5 MHzChina

(max erp <= 10 mW)EU US (max erp <=1 W)

Korea

Japan

(Max BW = 1MHz)

Region Tx power regulations

US Max e.r.p. <= 1 W

EU max erp <=14 dBmPSD <= -4.5 dBm/100KHz (863~868.6MHz)PSD <= 6.2 dBm/100KHz (865~868MHz)

Korea 3 mW or 10 mW (920.6~923.5MHz and six 200 KHz channels below 920.6 MHz)

China Max e.r.p. <= 10 mW

Japan 1mW , 20 mW or 250 mW (915.9~929.7MHz)Max BW <= 1 MHz

915.9 928 MHz

13.8 MHz

Rolf de Vegt, Qualcomm

doc.: IEEE 802.11-11/1238r0

Submission

Practical Applicability of Use Cases by Geography based on Spectrum Availability Considerations

Geo Sensor BackhaulFor Sensor

Extended Range Wi-Fi

Rationale

US Yes Yes Yes

EU Yes ? No • Stringent Duty Cycle Limitations• Only one 4MHz channel available

Japan Yes Yes No • No channel BW >1 MHz available

Korea Yes Yes No • Only 6.5MHz total BW available

China ? ? ? • TBD

Incremental market opportunity for 802.11

Larger Smaller Smaller • Extended Range Wi-Fi use case will most likely lead to feature adds to existing wi-fi devices

Slide 4 Rolf de Vegt, Qualcomm

doc.: IEEE 802.11-11/1238r0

Submission

Proposal for Transmission Bandwidths in 11ah

• Definitely need a 1MHz mode – Japan has a max BW limit– Need enough channels in regions like EU/Korea

• Limited spectrum

• 2 MHz mode needed for the following reasons– Accommodate waveforms that are multiples of 2 MHz channels, to meet the

extended range Wi-Fi use-case requirement• Need higher BWs for satisfying that use-case

– Ensure that 1 MHz waveforms can inter-operate globally with higher BWs

• We propose that the following BWs be supported in the standard– 1 MHz (Mandatory)– 2 MHz (Mandatory)– 4, 8 and 16 MHz (Optional)

Slide 5 Rolf de Vegt, Qualcomm

doc.: IEEE 802.11-11/1238r0

Submission

PHY Numerology for the Transmission BWs

• Propose to have the same tone spacing for all BW modes– Different BWs should be achieved through different FFT sizes– Helps in achieving co-existence if we have same symbol duration

• Propose to have 64 tones for the 2 MHz mode– Gives a long enough CP for outdoor deployments– Minimizes new design work as 11ac already has designs for up-to 512 pt FFT

• Modes >= 2 MHz become 10x down-clocking (expansion) in terms of symbol times and other related parameters in 11ac

– 1 MHz mode is the only mode which will need a new design

Slide 6 Rolf de Vegt, Qualcomm

doc.: IEEE 802.11-11/1238r0

Submission

Considerations regarding Mandatory 1MHz and 2MHz BW Modes

• For the US market alone, a minimum BW of 2 MHz would be highly feasible– May be preferable in some aspects

• However, we assume vendors’ desire to create global products as much as possible– Experience of Wi-Fi technology thus far

• Global market requires a 1 MHz bandwidth mode

• Full interoperability and coexistence between 1MHz and 2MHz modes– Stakeholders in 802.11ah likely to demand this– Makes the standard less vulnerable to potential regulatory changes– Simplifies co-existence and transmission of management frames– Assuming that the standard will contain a 1 MHz mode, there is no way to control where

devices in 1 MHz are deployed• Regulatory bodies don’t police this• WFA does not test for this either

Slide 7 Rolf de Vegt, Qualcomm

doc.: IEEE 802.11-11/1238r0

Submission

Proposal for Channelization

• Channelization for different regions– 2, 4, 8, 16 MHz in the US

• With 26 MHz of spectrum, provides 13 channels• No wastage of spectrum at the edges

– 1, 2, 4 MHz in EU/ Korea• Limited spectrum makes 1 MHz channels necessary

– 1 MHz in Japan• Max BW limit in Japan makes 1 MHz necessary• Channelization much smaller than 1 MHz would encourage modes which are

difficult to design as interoperable modes with higher BW modes– China, TBD

• Two possible options (contingent on regulatory developments)– Ability to use 779~787MHz (TV Bands)– Expansion of channel width to1 or 2 MHz in the future in some of the other bands

Slide 8 Rolf de Vegt, Qualcomm

doc.: IEEE 802.11-11/1238r0

Submission

Resulting Global Channel AvailabilityGeo Freq

(MHz)BW Max BW

allowedTx Power Regulations

Other limitations

# of 1MHz Ch

# of 2MHz Ch

# of 4MHz Ch

US 902 - 928 26 MHz Max e.r.p. <= 1 W n/a 13 6

EU 863 -868.6 5.6 MHz

max erp <=14 dBm

PSD <= -4.5 dBm/100KHz (863~868.6MHz)

PSD <= 6.2 dBm/100KHz (865~868MHz

High power RFID (2W!) share the band 865-868MHz (hence allowing much higher PSD)Duty cycle limitation of 2.8% for a given 200KHz (max 100sec transmission in 1 hour)

5 2 1

Japan 915.9-929.7 13.8 MHz

1 MHz 1mW , 20 mW or 250 mW (915.9~929.7MHz)Max BW <= 1 MHz

13 0 (6) 0 (3)

Korea 917 – 923.5 6.5 MHz

3 mW or 10 mW (920.6~923.5MHz and six 200 KHz channels below 920.6 MHz)

6 3 1

China 779 – 787 8 MHz ? Max e.r.p. <= 10 mW ? ? ?

Slide 9 Rolf de Vegt, Qualcomm