Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [An Etiquette for 60 GHz Band Access?] Date Submitted: [17 September 2007] Source:[Jason A. Trachewsky1, Christopher Hansen1, Jeyhan Karaoguz1, Ali S. Sadri2, Amer Hassan3, John Dorsey4, Pratik Mehta5, Bruce Montag5, Tom Cowling6, Brian Hart7, Gal Basson8, Tal Tamir8] Company [1Broadcom Corporation, 2Intel Corporation , 3Microsoft Corporation, 4Apple, 5Dell, 6Linksys, 7Cisco, 8Wilocity] Address [See next page for contact information] Voice: [], FAX: [], E-Mail: [] Re: Abstract: [We present the opportunities and coexistence challenges that exist in the 60 GHz band. Different communication solutions are likely be required to answer the different proposed usages. The 60GHz band, being unlicensed/license-free, may also be used for purposes not covered by TG3c. The need for some common rules of conduct by devices using the 60GHz band is discussed, and the problems with developing such an “etiquette” for band access by disparate devices are posed as a challenge to the reader.] Purpose: [This document is submitted as an informative contribution to TG 3c.] Notice: This document has been prepared to assist the IEEE P802.15. 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 acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15. Jason A. Trachewsky et. al., Broadcom

2. Contact information • Jason A. Trachewsky • Broadcom Corporation, 190 Mathilda Place, Sunnyvale, CA 94086 U.S.A. • Voice: +1-408-543-3319, Fax: +1-408-543-3399 • jat@broadcom.com • Christopher Hansen • Broadcom Corporation, 190 Mathilda Place, Sunnyvale, CA 94086 U.S.A. • Voice: +1-408-543-3378, Fax: +1-408-543-3399 • chansen@broadcom.com • Jeyhan Karaoguz • Broadcom Corporation, 5300 California Avenue, Irvine, CA 92617 U.S.A. • Voice: +1-949-926-6168, Fax: +1-949-926-9247 • jeyhan@broadcom.com • Ali S. Sadri • Intel Corporation, San Diego, CA U.S.A. • Voice: +1-858-774-6202 • ali.s.sadri@intel.com • Amer A. Hassan • Microsoft Corporation, One Microsoft Way, Redmond WA 98052  U.S.A. • Voice:  +1-425-705-9590, Fax:  +1-408-705-9590 • AmerH@microsoft.com • John Dorsey • Apple, Inc., 1 Infinite Loop, Cupertino, CA 95014 U.S.A. • Voice: +1-408-974-3722, Fax: +1-408-974-6051 • jdorsey@apple.com Jason A. Trachewsky et. al., Broadcom

3. Contact information • Pratik Mehta • Dell, Inc., One Dell Way, Round Rock, Texas 78682 U.S.A. • Voice: +1-512-338-4400 • Pratik_Mehta@dell.com • Bruce Montag • Dell, Inc., One Dell Way, Round Rock, Texas 78682 U.S.A. • Voice: +1-512-723-6053 • Bruce_Montag@dell.com • Tom Cowling • Linksys, a division of Cisco Systems, 2901 3rd Ave., Seattle, WA 98121 U.S.A. • Voice: +1-206-256-3416 • tocowlin@cisco.com • Brian Hart • Cisco Systems, 170 W. Tasman Dr., San Jose, CA 95134 U.S.A. • Phone: +-408-525-3346 • brianh@cisco.com • Gal Basson • Wilocity, Inc. 21 Bareket St., Caesarea, Israel. • Voice: +972-, Fax +972- • gal.basson@wilocity.com • Tal Tamir • Wilocity, 21 Bareket St., Caesarea, Israel. • Voice: +972-, Fax +972- • tal.tamir@wilocity.com Jason A. Trachewsky et. al., Broadcom

4. Outline • The range of 60 GHz applications • 60 GHz coexistence issues • An etiquette for band usage? Jason A. Trachewsky et. al., Broadcom

5. Applications in the 60 GHz Band • Wireless high speed cable replacement • notebook docking • display cables: monitors, HDTV, projectors • external storage • peripherals • “Sync and go” applications • short-range fast point to point transfer • Future Gbps WLAN • Fixed Point-to-Point Bridges • All with one radio • Simplifies addition of new wireless features to platforms • But, all of these applications could share the band High Speed Cable Replacement Sync & Go WLAN Jason A. Trachewsky et. al., Broadcom

6. Applications in the 60 GHz Band • Some examples of the diversity of needs: • PC peripheral interconnect • External storage and other peripherals • Short range (< 3 m). • Lowest cost and complexity. • May use low-gain antennas. • Some applications require very low latency (microseconds). • High density deployment (office) Jason A. Trachewsky et. al., Broadcom

7. Applications in the 60 GHz Band • Sync and go / file transfer • Transfer to portable and hand-held devices • Intermediate range (1-5 m) • Low to intermediate cost and complexity • Lowest power consumption • Generally has higher peak/average data rate ratio • Strict (Isoc.) low latency less important than peak throughput Jason A. Trachewsky et. al., Broadcom

8. Applications in the 60 GHz Band • Wireless display cable replacement • Notebook docking to monitor, projector, or HDTV • Needs to function within a cubicle (<3m) @ office density, or single room (~10m) • Highest cost and power consumption • Power efficiency important in some platforms • High peak and average data rates • Likely will use high-gain antennas or arrays • Latency is a concern (but, milliseconds) Jason A. Trachewsky et. al., Broadcom

9. Applications in the 60 GHz Band • Wireless LAN • Needs to function over multiple rooms (> 10m range) • Power efficiency important in some platforms • High peak and average data rates • Likely will use high-gain antennas or arrays • Latency is less of a concern (a few to 10s of milliseconds) Jason A. Trachewsky et. al., Broadcom

10. Outline • The range of 60 GHz applications • 60 GHz coexistence issues • An etiquette for band usage? Jason A. Trachewsky et. al., Broadcom

11. 60 GHz Co-existence Issues • In all likelihood, there will be multiple communication systems utilizing the unlicensed/license-free 60 GHz band. • We should consider whether to design for the existence of proprietary devices and the risks of not having one standard . • The vast differences in applications using the links and the time required to develop/publish a standard increase the risk we must solve coexistence problems. Jason A. Trachewsky et. al., Broadcom

12. 60 GHz Co-existence Issues • Can we get all these applications to conform to a single PHY and MAC spec.? • Given the wide range of applications and requirements, this outcome appears unlikely. Jason A. Trachewsky et. al., Broadcom

13. 60 GHz Co-existence Issues • Is there bandwidth enough to divide between all users without coordination of some sort? • Unlikely, since the current band plan only allows three channels in most countries. Jason A. Trachewsky et. al., Broadcom

14. Outline • The range of 60 GHz applications • 60 GHz coexistence issues • An etiquette for band usage? Jason A. Trachewsky et. al., Broadcom

15. An Etiquette for Band Usage? • Establish an “etiquette” for the use of this unlicensed band to minimize interference. • The etiquette does not solve all the problems that would be solved with a single standard for the band. • However, if widely adopted, it does help avoid “chaos” in the band if a single standard does not emerge or if there are proprietary devices. • We obviously prefer a single PHY/MAC! • The etiquette would become part of the PHY/MAC spec. Jason A. Trachewsky et. al., Broadcom

16. An Etiquette for Band Usage? • What is an etiquette? It may include: • Channelization rules • Channel center frequencies, including sub-channelization • Transmit spectral masks • Receiver adjacent channel interference • Temporal usage rules • Channel selection policies to minimize interference • Channel selection policies to minimize bandwidth fragmentation • Channel-access policies to minimize interference between co-channel users • Minimum-listen and maximum-idle periods • Busy-detect receiver thresholds relative to EIRP (?) • Maximum amount of time allowed for a transmission or burst of transmissions • Minimum gap between different users that are not coordinated and which overlap according to the channelization rules (?) • Other components? Jason A. Trachewsky et. al., Broadcom

17. An Etiquette for Band Usage? • Given the range of product requirements there should be no assumption of a central coordinator. • We may also not have a common signaling format (TBD). Jason A. Trachewsky et. al., Broadcom

18. Some Comments on Channelization • Standardize primary channel center frequencies and bandwidths: fc_pri = 58320 + k*2160 MHz, k = 0..3. • Are we happy with the low-rate/half-rate modes (sub-channelizations)? • We should probably standardize any sub-channelizations. Jason A. Trachewsky et. al., Broadcom

19. Beyond Channelization • We probably need a set of basic DFS rules to which all devices adhere. • Need to determine whether a channel is generally in use. • Because we’re dealing with an unlicensed/license-free band, we can expect foreign interferers that may require a change in channel. • Otherwise, video is glitched, bus transactions stall, etc. Jason A. Trachewsky et. al., Broadcom

20. Beyond Channelization • When moving to a new channel and re-locking the frequency synthesizer, we need to wait some period of time to determine whether the channel is “good”. • This wait time is probably reasonable for video cable replacement (latency < ~1 msec.). • It may be a problem for wireless peripheral links (for storage, etc., a few usecs latency). Jason A. Trachewsky et. al., Broadcom

21. Temporal Usage Rules • We can either assume that all devices use the same fundamental MAC protocol or we can drop that assumption and impose a simpler set of rules for sharing the channel by devices implementing different MAC protocols. • We may want a rule stating how long a device or a group of associated devices adhering to a common set of protocols may use a shared channel without deferring to a another device or a device outside that group. • The detection problem becomes difficult because of the need for large antenna / antenna array gains to achieve high rates using 60 GHz carrier frequencies. Jason A. Trachewsky et. al., Broadcom

22. Unanswered Questions • Shall an etiquette impose a peak EIRP limit that depends on burst detector sensitivity (to minimize the impact of hidden victims of interference)? • We cannot expect a simple wireless interconnect to have the same rx sensitivity as a video cable replacement link – but it may also have lower EIRP needs. Jason A. Trachewsky et. al., Broadcom

23. Unanswered Questions • The problem is actually more complicated, since there can be tx/rx asymmetries in gain in the direction of an unintended recipient. • Shall an etiquette mandate transmission and reception of a simple modulated signal for baseline link maintenance and device capabilities announcement? Jason A. Trachewsky et. al., Broadcom