1. 160 MHz PHY Transmission Date: 2010-03-17 Authors: March 2010
Month Year
doc.: IEEE yy/xxxxr0
March 2010
160 MHz PHY Transmission
Date:
Authors:
Youhan Kim, et al.
John Doe, Some Company

2. Outline Motivation Usefulness of 160 MHz PHY transmission mode
March 2010
Outline
Motivation
Usefulness of 160 MHz PHY transmission mode
Contiguous and non-contiguous 160 MHz
Coexistence
Summary
Youhan Kim, et al.

3. March 2010
Motivation (1/2)
WLAN continues to provide wireless alternatives to wired LAN
10BASE-T Ethernet: 11a/g
100BASE-T Ethernet: 11n
Ability to meet the 1000BASE-T Ethernet throughput (Gigabit wireless) in 11ac would be beneficial
Parallelism with past efforts lends additional legitimacy to 11ac
Could be a clear and simple part of the answer to “what is 11ac?”
Including this capability increases the chance of a major upgrade cycle, and provides better differentiation with previous generation equipments
Youhan Kim, et al.

4. March 2010
Motivation (2/2)
However, for Gigabit wireless to succeed, it needs to be practical
Achieve 1Gb/s TCP/IP throughput robustly over a reasonable range
Allow wide range of devices, each with different physical limitations (e.g number of antennas), to achieve 1 Gb/s TCP/IP throughput
We believe this capability would be instrumental in broader acceptance of 11ac by consumers
Youhan Kim, et al.

5. Usefulness of 160 MHz PHY Transmission
March 2010
Usefulness of 160 MHz PHY Transmission
WLAN is becoming prevalent in all types of devices
Different devices have different physical (e.g. number of antenna) limitations
160 MHz allows even wider range of devices to achieve Gigabit wireless
Opens the door for even more variety of applications
# Streams
MCS BW
#data tones / symbol
MAC Throughput* 8
256-QAM 5/6
40 MHz
108
1.12 Gbps 4
80 MHz
234+
1.21 Gbps 3
64-QAM 5/6
160 MHz
468+
1.37 Gbps 2
* Short GI, 70 % MAC efficiency
+ Tentative numbers. Exact number TBD.
Youhan Kim, et al.

6. Benefits of Wide Bandwidth
March 2010
Benefits of Wide Bandwidth
A wide channel shared among multiple users is more efficient for transporting bursty computer networking data
Modern media codecs use variable bit rates
Wide shared channels are more efficient due to statistical multiplexing
Streams with highly varying bit rate may be more robust with wide channels
Allows sufficient excess BW to meet the peak requirements
Particularly with prioritized QoS
Spectrum that is not used is permanently wasted
Youhan Kim, et al.

7. Contiguous and Non-Contiguous 160 MHz
March 2010
Contiguous and Non-Contiguous 160 MHz
Contiguous 160 MHz
Transmitted signal consists of a single contiguous frequency spectrum with 160 MHz bandwidth
Non-contiguous 160 MHz
Transmitted signal consists of two frequency segments, each 80 MHz wide
Limit to two non-contiguous segments for reasonable tradeoff between complexity and flexibility
WLAN MHz
U-NII 1
U-NII 2
U-NII Worldwide
U-NII 3
WLAN MHz
Radar
Radar
WLAN
WLAN
80 MHz
WLAN
80 MHz
U-NII 1
U-NII 2
U-NII Worldwide
U-NII 3
Youhan Kim, et al.

8. March 2010
Non-Contiguous 160 MHz
When the two frequency segments are placed next to each other, a non-contiguous 160 MHz device and a contiguous 160 MHz device shall be interoperable
The two frequency segments are used synchronously
Both in TX or both in RX mode
Signal on the two segments are destined to the same receiver(s)
WLAN MHz
Radar
Radar
WLAN
WLAN
80 MHz
WLAN
80 MHz
U-NII 1
U-NII 2
U-NII Worldwide
U-NII 3
Youhan Kim, et al.

9. Contiguous and Non-Contiguous 160 MHz
March 2010
Contiguous and Non-Contiguous 160 MHz
Contiguous 160 MHz
Suitable for devices with limitation on complexity, area, power, etc.
Non-contiguous 160 MHz
Higher probability of being able to operate in wide bandwidth mode [1]
Able to move around 80 MHz segments to avoid radar and WLAN
Able to utilize U-NII 3
More effort and cost required to build than contiguous 160 MHz devices
To allow different implementations to independently decide on the tradeoffs between contiguous and non-contiguous operation
Allow 160 MHz devices that support only contiguous 160 MHz operation
160 MHz devices may optionally support non-contiguous 160 MHz operation as well
WLAN MHz
Radar
Radar
WLAN
WLAN
80 MHz
WLAN
80 MHz
U-NII 1
U-NII 2
U-NII Worldwide
U-NII 3
Youhan Kim, et al.

10. Coexistence Not as hard as 11n at 2.4GHz
March 2010
Coexistence
Not as hard as 11n at 2.4GHz
No 11b and Bluetooth
No partially overlapping channels (i.e., 5MHz channel spacing at 2.4GHz)
No limited capabilities of pre-standard 11ac devices (as in 11n)
Various mechanisms may be investigated to ensure coexistence with legacy devices (11a/n)
Some examples of existing 11n mechanisms
Immediate CCA sensing on all BW units
RTS/CTS protection
L-SIG spoofing
Intolerant bit
Some examples of possible new mechanisms
Channel activity profiling on extension channels
More information exchanges between AP and STA on channel profiling
Ability to reserve certain channels for high QoS data
Youhan Kim, et al.

11. March 2010
Summary
160 MHz PHY transmission would be a valuable optional feature in 11ac
Allows even wider range of devices to achieve Gigabit wireless
Allow both contiguous and non-contiguous 160 MHz operation
Non-contiguous and contiguous modes shall interoperate when the two 80 MHz non-contiguous segments are placed next to each other
Allow 160 MHz devices that support only contiguous 160 MHz operation
Allow each implementation to independently decide on the tradeoffs between contiguous and non-contiguous operation
Youhan Kim, et al.

12. March 2010
References
[1] Cariou, L. and Benko, J., Multichannel transmissions, IEEE /0103r1, Jan. 2010
Youhan Kim, et al.