120 MHz PHY Transmission Date: 2010-07-12 Authors: January 2010 doc.: IEEE 802.11-10/0084r3 120 MHz PHY Transmission Date: 2010-07-12 Authors: Brian Hart, Cisco Systems

January 2010 doc.: IEEE 802.11-10/0084r3 Brian Hart, Cisco Systems

Abstract The 120 MHz PHY transmission is proposed for 802.11ac to efficiently support the 5 GHz spectrum of China.

Background 802.11ac will support wider bandwidth than 802.11n in 5 GHz frequency band. In the May 2010 Beijing meeting, the 160 MHz PHY transmission is accepted in the 802.11ac specification framework. Compared with 40/80 MHz transmisstion, 160 MHz PHY transmission has the following advantages Reduce the complexity requirement which allows wider range of devices to achieve Gigabit wireless throughput. Achieve more efficient data transmissions Increase the coverage of 802.11ac networks Enable more applications

only 125 MHz availabe in China Motivation Unfortunately, 160MHz bandwidth around 5 GHz is not available worldwide. In China, the total bandwidth available for WLAN systems around 5 GHz is 125 MHz (5,725 ~ 5,850 MHz). Obviously, the 160 MHz transmission cannot be used in China. Chinese users cannot enjoy the advantages of wider bandwidths, which may reduce the competitiveness of 11ac. Compared with other regions’ users, Chinese users have to experience higher complexity, worse performance, less device types, and less applications. 160 MHz PHY Transmission only 125 MHz availabe in China 5,725 MHz 5,850 MHz 35 MHz

Motivation China is the biggest potential market of 802.11ac More than 700 million mobile phone users More than 400 million Internet users More than 400 million TV sets, which is the potential market of wireless display applications. Chinese telecommunication operators are promoting 3G + WLAN programs into practice, and have deployed a large number of WLAN hotspots in China. Therefore, it is very necessary for 802.11ac to define a PHY transmission which is suitable for the Chinese 5GHz spectrum.

120 MHz PHY transmission Following the Chinese spectrum and the existing 11ac tone allocations, we propose 802.11ac to support the 120 MHz PHY transmission. The 120 MHz PHY transmission can be realized by multiple approaches (need to be further studied) Combine three 40 MHz channels Combine an 80 MHz channel with a 40 MHz channel Design a single 120 MHz channel …

Achieving 1 Gbps and higher throughput 120 MHz transmission can achieve 1 Gbps throughput with lower order MIMO and MCS. # Streams MCS BW #data tones / symbol MAC Throughput* 8 256-QAM 3/4 40 MHz 108 1.01 Gbps 16-QAM 3/4 80 MHz 234 1.09 Gbps 6 64-QAM 2/3 4 16-QAM 1/2 120 MHz 324 16-QAM 2/3 3 1.13 Gbps In this Table, we assume the 120 MHz bandwidth is composed of three 40 MHz channels. More than 3 Gbps throughput can be obtained when 8 streams, 256 QAM, and 3/4 channel code are adopted.

Main advantages 120 MHz PHY transmission has the following major advantages: Achieve better and more robust performance Increase the coverage of 802.11ac networks Reduce the implementation cost Allow additional types of devices to achieve 1 Gbps throughput and thus may enable new applications Increase the data throughput by 50%, compared with 80 MHz transmission Achieve more than 3 Gbps and support uncompressed 1080p video transmission.

Summary A 120 MHz PHY transmission mode is proposed for 802.11ac to efficiently support the 5 GHz spectrum of China, which is very important to promote 802.11ac applications in China. The 120 MHz PHY transmission mode can achieve 1 Gbps throughput with lower order MIMO and MCS, increase data throughput by 50%, compared with 80 MHz transmission, support more than 3 Gbps data transmission, e.g., uncompressed 1080p video stream. The 120 MHz PHY transmission can be implemented by multiple solutions, which need to be further studied. three 40 MHz channels an 80 MHz channel + a 40 MHz channel a single 120 MHz channel …

Strawpoll #1 Do you support adding the following section and item into the specification framework document, 11-09/0992? Section 3.1.2 120 MHz PHY Transmission R3.1.2.A: The draft specification shall include support for 120 MHz PHY transmission. Yes: No: Abstain:

References 11-10-0378-01-00ac-160-mhz-phy-transmission 11-09-0992-11-00ac-proposed-specification-framework-for-tgac