Channelization for China’s Spectrum January 2010 doc.: IEEE 802.11-10/0084r3 Channelization for China’s Spectrum Date: 2010-11-10 Authors: Brian Hart, Cisco Systems

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

Abstract In this presentation, we propose some candidate channelization schemes for China’s 5GHz spectrum.

Background In the last meeting, the following statement was included in the 11ac spec framework. R3.1.E: The draft specification shall include support for an efficient channelization in China’s (5,725 ~ 5,850 MHz) spectrum. In [3], it is shown that the total channel bandwidth in China can be up to 120MHz. In China, the coexistence and compatibility issues are actually not serious, but still need to be considered. In China, very few 802.11 devices (esp. APs) work on 5GHz band. Almost all legacy 5GHz devices can also support 2.4GHz band, and the 2.4 GHz band is the preferred working band. If the spectrum regulation of China remains unchanged, defining an 120MHz channelization can keep a chance for 802.11ac to meet the Chinese requirement.

How to do channelization June 2010 doc.: IEEE 802.11-10/xxxxr0 How to do channelization Easier networking and better interference avoidance The number of channels should be as many as possible, e.g., three 40MHz channels, six 20MHz channels. Higher data throughput The channel width should be as large as possible. An option is to define an 120MHz channel in China’s spectrum Compatibility and coexistence insurance The channelization should support legacy 802.11a/n devices The channelization should support coexistence with OBSSs working in legacy channels. Brian Hart, Cisco Systems

Proposal 1 Proposal 1 includes two modes (compatibility mode and enhanced mode), in which the 120MHz channel is optional. 7.5MHz 5735 40MHz 80MHz 20MHz 5727.5 5847.5 f MHz 120MHz 5835 12.5MHz Compatibility mode Enhanced mode Compatible with legacy devices Higer channel utilization efficiency

Proposal 2 Proposal 2 consists of the existing 11ac channelization and an optional 120MHz channel. 7.5 5735 40MHz 80MHz 20MHz 5727.5 5847.5 f MHz 120MHz 5835 12.5 Compatible with legacy devices Higher data throughput

June 2010 doc.: IEEE 802.11-10/xxxxr0 Conclusion Proposal 1 is an efficient and complete channelization scheme, but faces challenges in compatibility and coexistence. Proposal 2 keeps the existing 20/40/80 MHz channels, has less compatibility and coexistence problems, and is easier to be implemented. Like 160MHz channel, the 120MHz channel is optional. The 120MHz channel design is still open, and may be realized by combining the existing 40MHz and 80MHz channels or defining a new waveform. Some MAC mechanisms have been provided by the co-authers to support our proposals. Brian Hart, Cisco Systems

References 11-10-0778-01-00ac-120-mhz-phy-transmission 11-10-1062-02-00ac-rf-feasibility-120-mhz-channelization 11-09-0992-15-00ac-proposed-specification-framework-for-tgac

Solution 1: BSS alternatively operating on shifted and non-shifted channels in time domain

Solution 2: Enable 120 MHz Transmission via PCO Enable 120 MHz transmission using Phased Coexistence Operation (PCO) The procedure already exists in 11n to enable alternation of 20 and 40 MHz phases in 11n; a simple extension can be made for 11ac

Solution 3: Enable 120MHz data only transmission period (burst-style) Basically burst-style time division of legacy transaction period and 120MHz data only transmission period Only data frames and some management frames transmitted with 120MHz bandwidth; Control frames and most networking joining related management frames transmitted with current channels.

Solution 4: Enable 120MHz data only transmission period Allow phased division of legacy transaction period and 120MHz data only transmission period AP controlled or STA requested phased division of legacy transaction period and 120MHz data only transmission period CCA detection on 5 non-shifted 20MHz channels. If all 5 channels are idle, then AP sends CTS-to-self on 5 non-shifted 20MHz channels to reserve 100MHz channel After120MHz transaction phase starts, AP and 120MHz recipient STAs exchange RTS/CTS on 5 legacy 20MHz channels to avoid OBSS interference LvKaiying, ZTE Corporation

Pre-motion 1 Do you support the following channelization scheme for China, and then modify the 11ac spec framework accordingly? In this scheme, the 120MHz channel is optional, 5735 40MHz 80MHz 20MHz 5727.5 5847.5 f MHz 120MHz 5835 Compatibility mode Enhanced mode

Pre-motion 2 Do you support the following channelization scheme for China, and modify the 11ac specification framework document accordingly? In this scheme, the 120MHz channel is optional. 5735 40MHz 80MHz 20MHz 5727.5 5847.5 f MHz 120MHz 5835