doc.: IEEE /288 Submission July 2002 Intel Research and Development Slide 1 Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [SG3a Coexistence Criteria Proposal] Date Submitted: [3 July, 2002] Source: [Jeff Foerster] Company [Intel Research and Development] Company [Intel Corporation] Address [JF3-212, 2111 N.E. 25 th Ave., Hillsboro, OR, 97124] Voice [ ], FAX: [ ] Re: [In response to comments taken on the selection criteria for an alternate high rate WPAN PHY.] Abstract:[This contribution proposes a definition and justification for a coexistence criteria that should be considered for the selection criteria for an alternate high rate WPAN PHY.] Purpose:[The purpose of this contribution is to more carefully define the coexistence criteria that the SG3a proposals should be measured against. This criteria is based upon a PHY Coexistence Characterization (PCC) that was proposed in the study group. Minimum criteria is also proposed for acceptance by the study group to influence future PHY proposals.] Notice:This document has been prepared to assist the IEEE P 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 P

doc.: IEEE /288 Submission July 2002 Intel Research and Development Slide 2 Coexistence Criteria Proposal Jeff Foerster Intel Research and Development Intel Corporation

doc.: IEEE /288 Submission July 2002 Intel Research and Development Slide 3 Overview of Talk Why address coexistence now? Coexistence definition –PHY Coexistence Characterization (PCC) –Justification of ‘fair and reasonable’ parameters Proposed minimum and desired requirements Other considerations Conclusions

doc.: IEEE /288 Submission July 2002 Intel Research and Development Slide 4 Why address coexistence now? Traditionally handled after the standard is developed –Limits coexistence mechanisms/tools Numerous standards being developed that will share the same spectrum –Importance increases as more devices are deployed and standards developed –Need to pass sponsor/letter ballot with support from other 802 groups Demonstrates a responsible industry –Government is giving the industry a chance to prove it can self-regulate itself in the unlicensed spectrum bands Especially true for UWB

doc.: IEEE /288 Submission July 2002 Intel Research and Development Slide 5 Coexistence Definition Characteristics of definition –Should be quantifiable –Should be relatively simple to evaluate –Should be representative of actual deployment scenario –Should be fair for both transmitting and receiving devices Current IEEE work on coexistence – : Draft Recommended Practices for and b (2.4 GHz) Collaborative (2 MAC + 1 PHY using Notch filter) and non-collaborative methods specific to the PHYs (packet selection, adaptive hopping) –Presentation in May, 2002 by Ember to use PHY Coexistence Characterization (PCC) Associated with (2.4 GHz coexistence)

doc.: IEEE /288 Submission July 2002 Intel Research and Development Slide 6 Coexistence Definition Possible approaches to definition –PHY BER or PER –PHY throughput –MAC throughput –MAC packet delays/collisions PHY Coexistence Characterization (PCC) –Easily quantifiable and related to MAC throughput impact May be pessimistic and does not include: MAC packet recovery algorithms, < 100% duty cycle for both systems –MAC throughput highly dependent on traffic assumptions and difficult to simulate

doc.: IEEE /288 Submission July 2002 Intel Research and Development Slide 7 Coexistence Definition Proposed Model (based on presentation on PCC by Robert Poor) –Reference Rx Nominal power is specified while d ref is only informative

doc.: IEEE /288 Submission July 2002 Intel Research and Development Slide 8 Coexistence Definition Critical parameters –Path loss model based on (free space up to 8m and 3.3 path loss exponent > 8 m) –Reference Rx performance criteria (BER < 10e-5 or PER < 0.08) –Reference Rx nominal power Proposed as 6 dB above standard Rx sensitivity –Same as b adjacent channel rejection spec. –Most systems will have a fade/interference margin > 6 dB –3 dB above Rx sensitivity level used in a adjacent channel rejection spec. –Want to ensure Rx nominal power reflects reasonable operation of reference system (d ref ) This is a key parameter that needs to be agreed upon by the a standards group for coexistence criteria

doc.: IEEE /288 Submission July 2002 Intel Research and Development Slide 9 Coexistence Definition Critical parameters –Interference distance at which reference Rx performance criteria is met This will be provided by proposers and will be PHY dependent Selection criteria should contain the minimal acceptable d int Proposed final definition (single parameter): –d int : The minimum distance between the SG3a Tx and reference Rx such that the reference Rx can maintain a BER < 10e-5 when operating at 6 dB above nominal Rx sensitivity level and both devices are actively transmitting and receiving. Initial list of reference devices: Bluetooth ( ), , b, and a

doc.: IEEE /288 Submission July 2002 Intel Research and Development Slide 10 Coexistence Definition Impact of 6 dB above standard Rx sensitivity level (sanity check) –Bluetooth Center frequency2.4 GHz Baud rate1 MHz ModulationGFSK Tx Power0 dBm Rx Antenna Gain0 dBi Rx Sensitivity-70 dBm Interference Margin6 dB Nominal Rx Power-64 dBm Range at Nom. Rx Power (d ref )12 m Bluetooth target applications are WPAN (~10 m) Designed to be interference limited due to expected congestion in 2.4 GHz band

doc.: IEEE /288 Submission July 2002 Intel Research and Development Slide 11 Coexistence Definition Impact of 6 dB above standard Rx sensitivity level (sanity check) – Center frequency2.4 GHz Baud rate11 MHz ModulationDQPSK Tx Power0 dBm Rx Antenna Gain0 dBi Rx Sensitivity-75 dBm Interference Margin6 dB Nominal Rx Power-69 dBm Range at Nom. Rx Power (d ref )17 m target applications are WPAN (~10 m) Can scale down to 11 Mbps with improved sensitivity

doc.: IEEE /288 Submission July 2002 Intel Research and Development Slide 12 Coexistence Definition Impact of 6 dB above standard Rx sensitivity level (sanity check) –802.11b Center frequency2.4 GHz Baud rate11 MHz ModulationCCK (11 Mbps) Tx Power20 dBm Rx Antenna Gain0 dBi Rx Sensitivity-76 dBm Interference Margin6 dB Nominal Rx Power-70 dBm Range at Nom. Rx Power (d ref )74 m WLAN applications for office will most likely be ACI and CCI limited Smaller cell sizes needed for greater density in office locations Home applications may need more protection to cover a home Can scale down data rate for longer range

doc.: IEEE /288 Submission July 2002 Intel Research and Development Slide 13 Coexistence Definition Impact of 6 dB above standard Rx sensitivity level (sanity check) –802.11a Center frequency5.3 GHz Baud rate11 MHz Modulation Number of carriers Carrier spacing 16-QAM Coded-OFDM (24 Mbps mode) KHz Tx Power15 dBm Rx Antenna Gain0 dBi Rx Sensitivity-74 dBm Interference Margin6 dB Nominal Rx Power-68 dBm Range at Nom. Rx Power (d ref )28 m WLAN applications for office will most likely be ACI and CCI limited Smaller cell sizes needed for greater density in office locations (~22 m) Home applications may need more protection to cover a home (no ACI or CCI) Can scale down data rate for longer range

doc.: IEEE /288 Submission July 2002 Intel Research and Development Slide 14 Coexistence Definition Is 6 dB above Rx sensitivity level ‘fair and reasonable’? –For some applications, yes. –For others, no. When is a system not otherwise interference limited? –Home environment with limited number of simultaneously operating devices (CCI and ACI less likely in many cases) –PC designs starting to reduce emissions in targeted RF bands What about Rx antenna gain? –0 dBi assumed, but can typically get 3-6 dBi What about efficient Rx designs that perform better than Rx sensitivity levels? –Future chips will be able to perform much better than published Rx sensitivity levels

doc.: IEEE /288 Submission July 2002 Intel Research and Development Slide 15 Minimum criteria What are reasonable values for d int ? –WPAN and WLAN devices will inevitably share the same space See numerous application presentations for the home and office b and HomeRF currently serving the home market a/g will be serving in near future with e QoS WNG/HTSG work getting started to improve a to better meet home requirements New bands may be opening up between GHz Combined WPAN and WLAN solutions offer significant potential for future applications –Fully integrated WPAN/WLAN solution not considered here (allows for possible coordination), but flexibility of solution will help enable –d int < 1 m and d int < 0.3 m have already been proposed and discussed in the requirements and selection criteria

doc.: IEEE /288 Submission July 2002 Intel Research and Development Slide 16 Minimum criteria Proposed Criteria –Minimum criteria (1): Under normal operating conditions, the proposed PHY must be able to provide a minimum level of coexistence such that d int < 1 meter with a 6 dB interference margin for the reference receiver. –Minimum criteria (2): The proposed PHY must be able to provide an enhanced level of coexistence such that d int < 0.3 meter with a 6 dB interference margin for the reference receiver (corresponding to 10 dB more protection than (1)). This means that, if an individual implementation wants to achieve this level of coexistence, it must be able to do so and still be able to communicate with a standard a receiver. DFS is an example of this kind of enhanced protection for a (being developed in h)

doc.: IEEE /288 Submission July 2002 Intel Research and Development Slide 17 Desired criteria Proposed Criteria –Desired criteria: The proposed PHY should be able to provide an enhanced level of coexistence such that d int < 0.3 meter with a 0 dB interference margin for the reference receiver. This means that, if an individual implementation wants to achieve this level of coexistence, it must be able to do so and still be able to communicate with a standard a receiver. Some vendors may wish to have the ability to provide even greater protection to other systems

doc.: IEEE /288 Submission July 2002 Intel Research and Development Slide 18 Other Considerations PHY proposals should use ‘Good Neighbor’ policies –Adaptive power control (do not transmit more power than needed) –Time division multiplexing (do not transmit for more time than needed) –Dynamic Frequency Selection (avoid interference if possible) Adaptive notch filtering Selectable frequency mask (for UWB?) –Implications on MAC to maintain connectivity?

doc.: IEEE /288 Submission July 2002 Intel Research and Development Slide 19 Other Considerations Practical concerns –How should proposals address coexistence? The more information the better Combination of analysis, semi-analytical monte-carlo simulations, or full simulations could be used Provide filter masks that show emitted power in the bands of interest –Only a first level approximation, and useful only for WGN-like interference Need justification of WGN approximation, if used, compared to pulsed or CW-like interference (specifically for UWB) Actual testing results if available –In the end, the task group will be responsible for ensuring coexistence of final solution (not just proposers)

doc.: IEEE /288 Submission July 2002 Intel Research and Development Slide 20 Conclusions Adopt the PHY Coexistence Criteria (PCC) to measure coexistence –Single parameter needed (d int ) Adopt minimum and desired criteria which I believe is fair and reasonable for all concerned –Minimum level of coexistence for all PHYs –Minimum level of flexibility for enhanced coexistence –Desired level of flexibility for enhanced coexistence –Could add other reference systems to coexistence list (cellular, cordless phones) Coexistence should not be taken lightly –Especially for UWB devices –Consumers will benefit in the end