January 17, 2006Doc: IEEE 802.15-06-0049-00-004a Kohno, Hara, Takizawa (NICT) Slide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks

Slide 1

January 17, 2006 Doc: IEEE 802.15-06-0049-00-004a

Kohno, Hara, Takizawa (NICT)

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

Submission Title: [Discussion Procedure for Regulatory and Coexistence Issues]Date Submitted: [January 17, 2006]Source: [Ryuji Kohno, Shinsuke Hara, and Kenichi Takizawa, Yuko Rikuta,] Company [National Institute of Information and Communications Technology

(NICT)]Contact: Ryuji Kohno.Voice:[+81 46 847 5104, E-Mail: [email protected]]Abstract: [Discussion Procedure for Regulatory and Coexistence Issues]

Purpose: [To help the discussion for answering no-vote comments to 15.4a draft]Notice: This document has been prepared to assist the IEEE P802.15. It is of

fered 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.

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Discussion Procedure for Regulatory and Coexistence

Issues

Ryuji Kohno, Shinsuke Hara, Ken-ich Takizawa

NICT

Slide 3



Agenda for discussion

1. Regulatory issues (1) Necessity of Interference reduction technology, e.g. DAA (2) Introduction and discussion of feasible DAA (3) Summary of issues in DAA for regulatory compliance2. Coexistence issues (1) Category of coexistence problem (2) Solution for regulatory requirement, i.e. simple DAA, LDC (3) Definition of LDC: necessary duty cycle in node & PCN etc

Regulatory requirement is to ensure coexistence by reasonable interference reduction technology, e.g. DAA, LDC.• Pick up and review the technical requirements (TRs) regarding “regulatory and coexistence issues” (pp.70-85)• Discuss remedies for them.

Slide 4



Note•We will discuss mainly the regulatory and coexistence issues in UWB band•The group proposing CSS in ISM band should separately discuss and show a possible coexistence between CSS and 11g and so on (they are responsible for filling out the blanks pointed by letter ballot)•In addition, the group proposing Sub-G UWB should separately discuss and show a possible coexistence between Sub-G UWB and 15.4(b) and so on

Slide 5



1. Regulatory Issues

736

722

150(E), 324(E), 645(TR), 646(TR), 647(TR), 660(TR), 696(TR), 698(TR), 722(TR),732(TR), 736(TR), 741(TR), 750, 754, 775, 788, 796

Ronald Brown FOCUS Enhancements

TR This standard does not appear to address regulatory requirements world-wide for use of UWB spectrum. While it appears to address US requirements

James Taylor Discretetime Communications (UK) Ltd.

TR The draft standard does not satisfy currently known regulatory requirements outside the US regulatory domain. In particular

Slide 6



Permissible signal Level: MS-114.8dBm/MHz

Aggregate Interference

density [nodes/km2] 1 100 500 1000p( I>PSL ) ― ― ―- <0.5%I1% ― ― ― -132dBm• p(I>PSL) means the probability that interference signal level exceeds the permissible one.

• I1% means the interference level at p( I>PSL)=1%.

• UWB signal level is -70dBm/MHz

Permissible signal level: MS-114.8dBm/MHz


density [devices/km2] 80 100 500 1000p( I>PSL ) 1% 1.5% 7% 30%I1% -

115.7dBm-114.3dBｍ

-107.3dB

m-

104.3dBm

• UWB signal level is -41.3dBm/MHz

(1) Necessity of Interference reduction technology, e.g. DAA: Interference study (1/2)

Assumption:• Activity factor: 5%• Free space propagation• Antenna gain: 0dBi

Next generation(4G) Cellular phone (Mobile station)

Acceptable

Not Acceptable

Interference reduction scheme, e.g. DAA, is needed

Slide 7



• p(I>PSL) means the probability that interference signal level exceeds the permissible one.• I1% means the interference level at p( I>PSL)=1%.

• UWB signal level is -70dBm/MHz

• UWB signal level is -41.3dBm/MHz

Assumption:• Activity factor: 5%• Wall attenuation: 12dB• Free space propagation• Antenna gain: 0dBi

Permissible signal level： BS-128.8dBm/MHz


density [devices/km2] 1 100 500 1000p( I>PSL ) ― ― ―- 0.0%I1% ― ― ― -146dBm

Permissible signal level： BS-128.8dBm/MHz


density [devices/km2] 25 80 100 500 1000p( I>PSL ) 1% 30% 50％ 100％ 100％I1% -129dBm -

126dBm-

125dBm -120dBm -117dBm

Next generation Cellular phone (Base station)

Acceptable

Not Acceptable

Interference reduction scheme, e.g. DAA is needed

(1) Necessity of Interference reduction technology, e.g. DAA: Interference study (2/2)

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Date: Mon, 16 Jan 2006 17:40:37 -1000Reply-To: [email protected]: Joe Decuir <[email protected]>Organization: MCCISubject: [802.15.4A] first cut at simple TG4a UWB DAA supportTo: [email protected]

(2) Introduction and discussion of feasible DAA

We also received the following e-mail after this Monday’s discussion:

This proposes to•allow a system with simple nodes & smart piconet controller(s) to implement DAA where needed.•keep the nodes cheap and simple

Slide 9



The points are

1) two pieces: a request for information, and the responding report1.1) the piconet says: tell me how much energy you measure, over how much time, in which channel1.2) the device replies to that specific request with a measured number2) create an informative annex that describes how the combination of elements could be used for simple DAA mitigation by a network.

He is ready for presentation. Let’s pay attention to it.

Slide 10



(3-1) Impact of DAA in UWB performance

PNCnodeband allocation

(b1,b2, or b3 )


(b2 or b3)

b1 b2 b3

victim system

frequency

PNC should support a detection (e.g., energy) functionality.

victim systemvictim system

interference

if channel b1 is assigned to piconets, thises piconets cause interference to the victim system.

Channel b1 is not assigned.

no interference

with DAAwithout DAA

Remark: Without DAA, UWB will be suffered by strong interference from other radio, in particular at ranging mode requesting high SINR.

Slide 11



(3-2) Strategy for DAA

SOP interference could be reduced by using optional pulse shaping (such as CoU, CS, and Linear combination) which give another orthogonality.

Strategy: Degradation of UWB performance due to limited available channels by DAA


victim system

By using DAA, the number of available channels would decrease. -> SOP interference will increase.

SOP interference


victim system

SOP interference

• Spreading sequence (C)• TH hopping pattern (C and NC)

• Spreading sequence (C)• TH hopping pattern (C and NC)• Pulse shaping (C and partial NC)

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• We need to consider the following issues.– How to detect signals from victim systems at the PNC

• Is one of CCA mode 1(energy detection), 2(carrier detection), or 3(1 and 2) applicable ?

– How to send request to measure the signal level (from the nodes to the PNC) and respond the measured values (from the PNC to the nodes).

– How to determine the initial channel.

(3-3)Summary of issues in DAA

PNC

node

PNC should support a detection (e.g., energy) functionality.

victim system

Reply

Request

Initial channel

Slide 13



2. Coexistence Issues

Shellhammer, Steve

Qualcomm

E E.3.3 76 　 TR The 802.11b PER curve assumes 1% CSS duty cycle. That is quite low.

Explain why you use only 1% duty cycle or supply a curve with higher duty cycle.

687

Shellhammer, Steve

Qualcomm

E E.3.3 79 　 TR Once again 1% duty cycle is assumed.

Increase duty cycle or explain why 1% is reasonable.

691

Shellhammer, Steve

Qualcomm

E E6-10 80,81 　 TR There is no analysis for the UWB PHY.

Add results for UWB PHY.

692

352(E), 353(E), 354(T), 355(T), 356(T), 357(T), 358(T), 359(T), 360(T), 361(T), 362(T), 363(T), 364(T), 365(T),366(T), 367(T), 368(T), 369(T), 370(T), 371(T), 372(T), 373(T), 374(T), 375(T), 376(T), 377(T), 446(T), 550(TR), 551(TR), 678(T), 664(TR), 677(TR), 678(TR), 679(TR), 680(TR), 681(TR), 682(TR), 683(TR), 684(TR), 685(TR), 686(TR), 687(TR), 688(TR), 689(TR), 690(TR), 691(TR), 692(TR), 693(TR), 694(TR), 696(TR), 697(TR), 698(TR), 700(TR), 721(TR), 731(TR), 732(TR), 759, 775, 792, 793, 796

Slide 14



Ronald Brown

FOCUS Enhancements

TR I don't think coexistence with existing UWB standards is adequately addressed in this draft. In particular

　721

Jason Ellis

Staccato Communications

TR Coexistence with existing UWB standards is not adequately addressed in this draft; specifically there should be particular mention of products compliant to ECMA-368

　731

Jason Ellis

Staccato Communications

TR This standard is likely not to be allowed for worldwide usage as it contains no provisions for operation in Asia or Europe. This system should incorporate detect and avoid measures to narrow-band incumbents.

Include work to address known regulatory environments in Europe

732

Slide 15



(1) Category of coexistence problem1.Coexistence between 802.15.4a systems and

other systems such as 802.16 (and 4G systems)

2.Coexistence between UWB systems such as 4a and 3a-like systems (MB-OFDM and DS-UWB)

This coexistence is possible byintroducing a DAA mechanism of CCA mode 1 or 2 in “6.9.9” discussed previously

A mechanism to detect the UWB signals in 4a PHY and MAC may be required

Slide 16



The reason for using 1% duty cycle in 2.4GHz band is vague

•Why don’t we introduce duty cycle in UWB band?•Can LDC solve all coexistence problems? If no, what can we do for solution?

•What is duty cycle?•Why and how is the value of 1% selected?•Is the value guaranteed for a device-to-device link or a piconet?•If the value is valid for a device-to-device link, then how can we guarantee such a low duty cycle for multiple piconet environments?

(2) Solution for regulatory requirement, i.e. simple DAA, LDCNecessity of the reason why LDC is good enough for suppression of interference to coexisting victim radio instead of DAA

Slide 17



•We suggest to have an Annex to show

•The Annex should clearly show that LDC can solve all the coexistence problems. Otherwise, a DAA mechanism should be introduced in 4a standard

•This is also closely related to the following comments regarding ALOHA:

•the definition of LDC (low duty cycle) and its value, say, 1%•how to guarantee the value in multiple piconet environments

(3) Definition of LDC

Slide 18



Shimada, Shusaku

Yokogawa Co.

5 5.4.4.1a

6 　 TR ALOHA without FDD should not have preferable characteristics of repercussion effect after temporal impediment, like as a traffic concentration. And this nature affects the coexisting neighbor 15.4a networks and other UWB networks.

Reconsider other than simple ALOHA without FDD.

Shimada, Shusaku

Yokogawa Co.

5 5.4.4.1a

6 　 TR ALOHA without FDD should not have preferable characteristics of repercussion effect after temporal impediment, like as a traffic concentration. And this nature affects the coexisting neighbor 15.4a networks and other UWB networks.

Reconsider other than simple ALOHA without FDD.

Øyvind Janbu

Chipcon

5 5.4.4.1a

6 25 TR The Aloha protocol introduced in subclause 5.4.4.1a (if included in the final standard) needs a more detailed specification. This subclause (in clause 5) is probably detailed enough

　

Øyvind Janbu

Chipcon

5 5.4.4.1a

6 26 TR From the draft: "In the Aloha protocol a device transmits when it desires to transmit without sensing the medium or waiting 26 for a specific time slot." and "An undesirable property of Aloha is that for network loading greater than about 18% of the network capacity 29 the network performance significantly declines due to collisions." In a 802.15.4 MAC

　

742

743

696

697

303(E), 305(E), 340(E), 442(T), 520(T), 696(TR), 697(TR), 742(TR),743(TR)

Slide 19



• In Europe, Draft ECC Decision ECC/DEC/(06)AA was under "public consultation" until the 24th of December 2005. A total of 67 comments were made, which will be dealt with during next meeting of the corresponding CEPT Task Group (TG3). The current version of the Decision allows UWB operation with the following emission limits (Table F2.3.1).

• It should be noted that the ECC Decision intends to deliver a clear message that the band 6 to 9 GHz is identified in Europe for long-term UWB operation without additional mitigation techniques.

• Some issues are expected to be solved end of March 2006 during the ECC meeting, from the revision proposal of the CEPT/TG3 February meeting. Indeed the TG3 meeting in February will try to solve the comments received during the public consultation. And the particular issue on the use of LDC as a relevant mitigation technique will be discussed and it is expected that some recommendations to the ECC will be provided from the TG3 listing the pros and cons of the LDC.

• Table F2.3.1 – current version of the ECC Decision on UWB emission limits, EIRP in dBm/MHz – subject to refinements in April 2006

F2.3 Applicable European rules to be updated in April 2006 in Annex F (informative): IEEE 802.15.4 and 802.15.4a regulatory requirements

Slide 20



• Note 1: In the frequency band 3.1 to 4.8 GHz, ECC has decided to investigate efficient mitigation techniques, such amongst others DAA (Detect And Avoid) mechanisms in order to ensure compatibility of UWB devices with radio services in the band with a view of allowing UWB devices in this band with maximum mean e.i.r.p. density of –41.3 dBm/MHz and a maximum peak e.i.r.p. density of 0dBm/50MHz. Duty-cycle limitation has also been identified as a possible mitigation technique. ECC will review this decision in the light of the results of these investigations.

• [Note for public consultation: Technical requirements for the Low Duty Cycle (LDC) mitigation may be solved before the final adoption of the Decision and therefore be incorporated as a separate note to the table of this Annex.]

F2.3 Applicable European rules to be updated in April 2006 in Annex F (informative): IEEE 802.15.4 and 802.15.4a regulatory requirements

Slide 21



• In Japan, a preliminary spectrum mask for indoor UWB was developed as a starting point for further studies and discussions on Japanese UWB regulation. This preliminary mask is shown in Figure F.2.4.1.

• This preliminary mask is developed to accelerate the completion of the Japanese UWB regulation by the Telecommunication Council of Ministry of Internal Affairs and Communications (MIC). Necessary adjustments to this preliminary UWB spectrum mask will be made by referring to the new study and discussion results.

• Figure F.2.4.1 Japanese preliminary mask (only indoor use).

F2.4 Applicable Japanese rules (To be updated in March 2006) in Annex F (informative): IEEE 802.15.4 and 802.15.4a regulatory requirements

Slide 22



• Notes:• 1) This preliminary mask is used under the condition that all UWB devices are

limited to only indoor use.• 2) For 3.400-4.8 GHz band (dotted area), the emission level of UWB devices

must be equal to or less than –41.3 dBm/MHz as that of the FCC rule when UWB devices are equipped with interference avoidance techniques such as Detect And Avoid (DAA). This is to protect systems of beyond IMT-2000, ENG, and other radiocommunication services, effectively. The emission level for UWB devices without interference avoidance techniques must be equal to or less than –70 dBm/MHz.

• 3) For 4.8-7.25 GHz band, the emission level of UWB devices must be equal to or less than –70 dBm/MHz.

• 4) For 7.250-10.25 GHz (hatched area by oblique line), the emission level of UWB devices must be equal to or less –41.3 dBm/MHz as the FCC rule.

• 5) For frequency band below 3.4 GHz, the emission level of UWB devices must be equal to or less than the transmission mask as defined in Table F.2.3.1.

• 6) For frequency band beyond 10.25 GHz, the emission level of UWB devices must be equal to or less than –70 dBm/MHz.

F2.4 Applicable Japanese rules (To be updated in March 2006) in Annex F (informative): IEEE 802.15.4 and 802.15.4a regulatory requirements

Slide 23



Backup slides

Slide 24



Suggested minor modification in specification:(Doc:802.15-05-0570-02-004a)

• Band plan: 3-5GHz with DAA, 6-10GHz without DAA

• Modulation: Sequence, PRF, Pulse Shape, FEC• MAC: Carrier and Energy Sensing for other

radios• Ranging: interference from coexisting radios• CSS: compliance in 2.4GHz band• Extra Functions: DAA

Slide 25



Suggested minor modification in specification (1/2)

• Band plan: 3-5GHz with DAA, 6-10GHz without DAA– 6-10GHz should be involved as well as 3-5GHz.– Common subbands allocation for European and Japanese masks as

well as FCC’s one.• Modulation: Sequence, Pulse Shape, PRF, FEC

– To shape UWB signal spectrum for avoiding interference to victim radios, e.g. 4G, sequence and pulse shape can be designed to make notches in spectral shape. PRF should be also high enough for low interference.

– To protect UWB devices against interference from strong coexisting radios, e.g. 4G, FEC should be designed with enough error-correcting capability so as to match with error features like error burst statistics. Super-orthogonal convolutional (SOC) codes with low encoding and decoding complexity and others are suggested.

Slide 26



Suggested minor modification in specification (2/2)

• MAC: carrier and energy sensing other radios as well– To achieve DAA adaptively, we need to sense a victim radio’s signal

like cognitive radio concept.– DAA may need modification of MAC as well as PHY. CBP

(Contention-Base Protocol) requested by FCC could be introduced to 4a as well.

• Ranging: interference from coexisting radios– Investigate ranging performance degradation due to interference from

coexisting radios.– Make ranging more secure and robust against jamming and the

interference.• CSS: compliance in 2.4GHz band• Extra Functions: DAA

Slide 27



Feasible Implementation of DAA for IEEE802.15.4aAdaptive interference avoiding techniques by SSA

Soft-Spectrum Adaptation (SSA)

Adaptive spreading sequence

Adapative pulse shaping• Pulse shaping by high-speed DAC• Pulse shaping by combining an waveletRef. Modified pulse shapes based on SSA for interference mitigation and systems coexistence (update), Doc: IEEE 802.15-03-0457-00-003a

•　 Spectrum null codingRef. Alternative Spreading Code and Channel Code for IEEE802.15.4a, Doc: IEEE 802.15-05-0462-01-004a

Adaptive band eliminating filter• Analog Implementation• Digital Implementation or hybrid

Documents

January 17, 2006Doc: IEEE 802.15-06-0049-00-004a Kohno, Hara, Takizawa (NICT) Slide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks