Thoughts on VHT Date: 2007-05-15 Authors: May 2007 April 2007 doc.: IEEE 802.11-07/0570r0 May 2007 Thoughts on VHT Date: 2007-05-15 Authors: Notice: This document has been prepared to assist IEEE 802.11. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.11. Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures <http:// ieee802.org/guides/bylaws/sb-bylaws.pdf>, including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair stuart@ok-brit.com as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE 802.11 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at <patcom@ieee.org>. Eldad Perahia, Intel Corporation Eldad Perahia, Intel Corporation

Abstract Some thoughts on direction and requirements for VHT May 2007 April 2007 doc.: IEEE 802.11-07/0570r0 May 2007 Abstract Some thoughts on direction and requirements for VHT Eldad Perahia, Intel Corporation Eldad Perahia, Intel Corporation

History of HT First high data rate presentation in WNG in Jan 2002 April 2007 doc.: IEEE 802.11-07/0570r0 May 2007 History of HT First high data rate presentation in WNG in Jan 2002 This was followed by numerous presentations on: PHY technology, including MIMO prototype MAC efficiency Markets and applications The first HTSG meeting was in Sept. 2002 The first TGn meeting was in Sept. 2003 HTSG lasted a year even with prep work done in WNG The process for forming VHT skipped the step of technology and market presentations in WNG This will need to be incorporated in VHT work We need to investigate markets and usage models We need to develop technical requirements from usage models Eldad Perahia, Intel Corporation Eldad Perahia, Intel Corporation

Requirements of VHT Create a focused PAR and five criteria April 2007 doc.: IEEE 802.11-07/0570r0 May 2007 Requirements of VHT Create a focused PAR and five criteria To borrow from HT/TGn Very high throughput Spectral efficiency Range/Robustness/Coverage Interoperability/Coexistence Any others? Eldad Perahia, Intel Corporation Eldad Perahia, Intel Corporation

Very high throughput May 2007 April 2007 doc.: IEEE 802.11-07/0570r0 May 2007 Very high throughput What increase in PHY rate are we looking for? 802.11: 2 Mbps in 25 MHz 11b: 11 Mbps in 25 MHz 11a/g: 54 Mbps in 20/25 MHz 11n: 300 Mbps in 20/25 MHz, 600 Mbps in 40 MHz VHT Another factor of 5? Bandwidth TGn increased the channel from 20 to 40 MHz Should VHT further increase channel BW? If so, how much? Do we use existing bands? Or new bands? What is the proper metric? The requirement for TGn was minimum of 100 Mbps throughput at MAC SAP Should we use throughput at MAC SAP? Network capacity? Will the TGn MAC support higher throughput/efficiency with higher PHY data rates? Will any modifications of the TGn MAC improve efficiency at higher PHY data rates, or do we need a new MAC? Eldad Perahia, Intel Corporation Eldad Perahia, Intel Corporation

Spectral efficiency Evolutionary ways to increase spectral efficiency: April 2007 doc.: IEEE 802.11-07/0570r0 May 2007 Spectral efficiency Evolutionary ways to increase spectral efficiency: More spatial steams TGn has 4 spatial streams Increase to 6 or more? Will the channel support more than 4 spatial streams? What is the antenna correlation with that many antennas on a platform? What platforms are we talking about? Higher order modulation and higher code rate Incremental increase in spectral efficiency by going to 256-QAM TGn has rate 5/6 code Increase to 7/8 or 1? Will Tx or Rx HW support this with impairments based on reasonable cost/complexity device? Eldad Perahia, Intel Corporation Eldad Perahia, Intel Corporation

Range/Robustness/Coverage April 2007 doc.: IEEE 802.11-07/0570r0 May 2007 Range/Robustness/Coverage We are LAN, we should strive to increase the data rate while maintaining coverage similar to TGn If we use higher frequencies, like millimeter wave, how do we maintain range comparable to current dot11 devices? Eldad Perahia, Intel Corporation Eldad Perahia, Intel Corporation

Interoperability/Coexistence April 2007 doc.: IEEE 802.11-07/0570r0 May 2007 Interoperability/Coexistence Coexistence with legacy devices turned out to be the most difficult topic in TGn Regarding coexistence in 5 GHz, in TGn arguments were made that there wasn’t much deployment of 11a devices in 5 GHz There will be large deployment of 11n devices in 5 GHz, similar arguments regarding backward compatibility can not be made Do we allow VHT in 2.4 GHz? Do we allow VHT in 5 GHz? If we use new spectrum, are there non-802.11 devices in the band and what are coexistence issues with these devices? Eldad Perahia, Intel Corporation Eldad Perahia, Intel Corporation

Relationship with IMT-Advanced April 2007 doc.: IEEE 802.11-07/0570r0 May 2007 Relationship with IMT-Advanced VHT should be independent of IMT-Advanced We should develop a PAR and 5-Critera that are based on technology and market requirements We do not want changes in requirements and timeline in IMT-Advanced to force PAR changes Eldad Perahia, Intel Corporation Eldad Perahia, Intel Corporation

Relationship with Video Transport Stream Study Group April 2007 doc.: IEEE 802.11-07/0570r0 May 2007 Relationship with Video Transport Stream Study Group Low compression, high rate video streaming is an obvious application which will drive requirements for both VHT and VTS We need to avoid overlap with VTS by maintaining good coordination between the two study groups Eldad Perahia, Intel Corporation Eldad Perahia, Intel Corporation

Summary PAR must be focused for successful TG April 2007 doc.: IEEE 802.11-07/0570r0 May 2007 Summary PAR must be focused for successful TG In order to achieve that, we need due diligence on markets, applications, and technology We need to have a good idea of whether VHT will be an evolutionary or revolutionary change to 802.11 Eldad Perahia, Intel Corporation Eldad Perahia, Intel Corporation