1-Aug-06 IEEE P802. 15-06-0358-00-004a

IEEE P802.15 Wireless Personal Area Networks

Project IEEE P802.15 Task Group 4a for Wireless Personal Area Networks (WPANs)

Title Notes on Sub-GHz operation

Date 1-Aug-06 Submitted

Source [Benjamin A. Rolfe] Voice: [408-395-7207] [ ] Fax: [] [ ] E-mail: [[email protected]] Re: 802.15.4a Comment Resolution

Abstract Addresses questions on regulatory situation and market viability regarding the sub-GHz channel.

Purpose To address comments submitted and questions raised during task group session.

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.

Submission: Notes on Sub-GHz operation B. Rolfe Page 1 15-06-0358-00-004a-notes-subghz-operation.doc 1-Aug-06 IEEE P802. 15-06-0358-00-004a

Notes on Sub-GHz operation Submission to the IEEE 802.15 Working Group B. Rolfe, 1-Aug-2006

Introduction Several questions have been raised regarding the viability of developing products based on the Sub-GHz UWB band present in the P802.15.4a draft. Prior submissions and external documents clearly establish the viable application, potential market, coexistence and regulatory considerations for UWB systems which provide location aware communication in the sub-GHz band.

The author provides this submission as an individual in response to specific questions raised in a ballot comment and subsequently in discussion during Task Group session. This submission provides an overview and references for support of development of the P802.15.4a amendment, based on experience the FCC in the U.S. As stated in the P802.15.4a draft, t is not within the scope of TG4A (or IEEE-SA) to provide interpretation of spectrum policy and regulations, or predict future policy. It is the responsibility of the implementer of the standard to identify and comply with applicable regulations.

Regulatory Authorizations for Sub-GHz UWB UWB is an emerging technology. The regulatory situation is dynamic and will continue to be for some time. In the U.S. the FCC has clearly indicated that it plans to revise UWB emission limits to be less conservative as real world data is obtained from actual deployments. Historically, safety of life applications such as location and tracking of emergency response personnel, and other public safety applications, have received favorable treatment from the FCC and other regulatory agencies.

Annex F of P802.15.4a Draft 3 (and subsequent) summarizes the known regulations and emission requirements, based on actual U.S. regulations and anticipated regulation elsewhere. Several prior submission 15.4a task group, for example [4], describe the advantages and trade- offs associated with the Sub-GHz band for particular applications. For location of personnel inside buildings, specifically emergency response personnel such as fire fighters and search and rescue crews, the Sub-GHz UWB channel is more favorable than higher frequencies, as the frequency dependent signal penetration characteristics are superior at the lower frequencies used by the sub-GHz UWB channel [9,10,11].

In the U.S. CFR47, Part 15 [1], Subpart F addresses UWB. Referring to 15.517, “Technical requirements for indoor UWB systems” limits are established for the radiated emissions at or below 960 MHz, and states such emissions from a device operating under the provisions of this section shall not exceed the emission levels in Section 15.209. This establishes an emissions mask for the sub-GHz UWB.

The FCC Report and Order [2] and CFR47, Part 15, Sub-part F further defines different categories of devices with different operating characteristics. The device applications enabled by Submission: Notes on Sub-GHz operation B. Rolfe Page 2 15-06-0358-00-004a-notes-subghz-operation.doc 1-Aug-06 IEEE P802. 15-06-0358-00-004a the precision ranging capability of 802.15.4a encompass several of the application categories described in the R&O and Sub-part F, for example by providing “location of objects or persons” (a characteristic of wall imaging systems per subpart F), in addition to digital data transfer. P802.15.4a systems are specifically defined to be low data rate, low duty cycle where location awareness (via precision ranging in the PHY) is the key differentiator. The R&O and sub-part F authorizes systems for “location of objects or persons” in the band below 960MHz will be permitted to operate at the emission limits contained in §15.209 and specific out-of-band emission limits.

The FCC repeatedly states the intention to consider other applications and issue approvals. In the R&O and subsequent documents the FCC emphasizes the conservative nature of Sub-part F and that these limits represents a “cautious first step”, and indicate an intent to “explore more flexible technical standards to address the operation of additional types of UWB operations and technology.” [2]. It has been further stated by FCC commissioners that they expect and intend to modify the categories for device applications and the limitations on such devices when provided real-world devices and data. The FCC has openly promoted UWB use in the location of emergency response personnel, such as firefighters, search and rescue crews, and further acknowledges that many yet to be identified applications will be significant and the FCC must be responsive to supporting such progress [3].

The FCC has approved UWB devices which exhibit characteristics of multiple categories showing a flexible interpretation of the sub-part F categories [8]. The intent of the FCC is further reinforced by the establishment of measurement procedures specific to the band below 960MHz.

The primary application for sub-GHz will be employed by safety of life emergency responders. The FCC has indicated that it will authorized use of UWB based personnel tracking systems for “Law enforcement, fire and emergency rescue organizations.”[1,2,3] The FCC has indicated that such applications will be approved if shown to work with existing services employed in similar circumstances. Several demonstrations have shown coexistence of sub-GHz UWB systems operating simultaneously with conventional radio systems, for example see the “Networks in the Extreme” (NetEx) program by the U.S. Defense Advanced Research Projects Agency (DARPA). Several regulatory domains outside the U.S., including Singapore and Canada, have funded development of UWB systems for this type of application. It is reasonable to expect that most regulatory domains will address such applications favorably. It should also be considered that in such applications, impact on incumbent users is mitigated by the situation, for example, interference with fringe DTV receiver inside a burning building is of minimal concern.

There is no requirement for 802 wireless systems to support exclusively license exempt operation. Several 802 standards utilize licensed spectrum. Should initial regulatory approvals be by license or waiver for specific applications, the benefits of standardization remains a valid as for licensed exempt situations.

Market Size From the earliest “Call for Applications” the 802.15 study group 4a identified “locating people” as an intended application. In the responses to the CFA, many respondents indicated applications for firefighter location, monitoring and telemetry; in fact this represents one of the Submission: Notes on Sub-GHz operation B. Rolfe Page 3 15-06-0358-00-004a-notes-subghz-operation.doc 1-Aug-06 IEEE P802. 15-06-0358-00-004a largest groups of application responses [6]. In the context of this type of personnel location in emergency response, the expected environment may be inside concrete and steel buildings, or underground. As stated above, in these environments, the propagation characteristics of sub-GHz are more favorable than higher frequencies.

Reference [7] provides the market estimates which were provided during the PAR and 5C development. This indicates that “Finding People” to be a significant market. Respondents sighting this application in their response include: Aetherwire, Harris, THALES, Samsung, TimeDerivative, Ubisense, City of Chicago. This shows that a number of commercial entities responded that this is a relevant application with sufficient market potential to justify the benefits of a standard to assure interoperability.

Other applications identified by multiple respondents, involve use of location aware devices in environments such as freight yards and warehouses where penetration may provide an advantage.

In the market evolution of wireless technologies, past history shows a trend with several “stages” of market adoption. The initial stage is typically moderate volume, high margin applications where enabling capability is higher priority than cost. The emergency response application provides a viable first step in market deployment where location performance (ranging) is more critical than cost, and to some extent, power consumption. This provides vendors the opportunity to develop 15.4a technology incrementally, with real revenue potential earlier than if this application space were not available.

References: 1. CFR 47, Part 15, Radio Frequency Devices 2. First Report and Order (FCC 02-48) [ET Docket No. 98-153] 3. Separate Statement Of Commissioner Michael J. Copps, February 14, 2002, RE: Revision of Part 15 of the Commission’s Rules Regarding Ultra-Wideband 4. P802.15.05-0390-010004a, Sub-GHz Overview 5. P802.15-03-0330-01-004a, IEEE P802.15.SG4a Call For Applications 6. P802.15-03-0442-00-004a, Categories for CFA SG4a Response 7. P802.15-03-0489-03-004a Application Requirement Analysis (XLS) 8. Some relevant FCC Approvals: a. L2C0030TR (Ranging + Data, Vehicle Location) b. L2C0023TR (Ranging + Data, Vehicle Location) c. QCJPAL1X1 (Ranging + Data, Asset Tracking) d. NUF-200EVK-1202 (Location + Data) e. ITQ-2150GR700 (Location + Data) f. ITQ-2150GR700 (Imaging + Data) 9. Modeling Omnidirectional Small Antennas for UWB Applications (Stanley Bo-Ting Wang, Ali M. Niknejad and Robert W. Brodersen) 10. Radiowave Propagation and Antennas for Personal Communications, K. Siwiak, 1998. 11. "The Indoor Radio Propagation Channel", H. Hashemi, Proc. IEEE,Vol 81, No 7, pp. 943-968, July 1993.

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