1、American National StandardDeveloped byANSI INCITS 371.1-2003for Information Technology Real Time Locating Systems (RTLS) Part 1: 2.4-GHz Air Interface ProtocolANSIINCITS371.1-2003Copyright American National Standards Institute Provided by IHS under license with ANSINot for ResaleNo reproduction or n
2、etworking permitted without license from IHS-,-,-Copyright American National Standards Institute Provided by IHS under license with ANSINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-ANSIINCITS 371.1-2003American National Standardfor Information Technology Real Ti
3、me Locating Systems (RTLS) Part 1: 2.4-GHz Air Interface ProtocolSecretariatInformation Technology Industry Council (ITI)Approved July 25, 2003American National Standards Institute, Inc.AbstractThis standard defines one of the two air interfaces with multiple subcomponents for a class of Real TimeLo
4、cating Systems (RTLS) for use in asset management. This standard is intended to allow for compatibil-ity and to encourage interoperability of products for the growing RTLS market.Copyright American National Standards Institute Provided by IHS under license with ANSINot for ResaleNo reproduction or n
5、etworking permitted without license from IHS-,-,-Approval of an American National Standard requires review by ANSI that therequirements for due process, consensus, and other criteria for approval havebeen met by the standards developer.Consensus is established when, in the judgement of the ANSI Boar
6、d ofStandards Review, substantial agreement has been reached by directly andmaterially affected interests. Substantial agreement means much more thana simple majority, but not necessarily unanimity. Consensus requires that allviews and objections be considered, and that a concerted effort be madetow
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8、ards.The American National Standards Institute does not develop standards andwill in no circumstances give an interpretation of any American NationalStandard. Moreover, no person shall have the right or authority to issue aninterpretation of an American National Standard in the name of the AmericanN
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10、titute require that action be taken periodically to reaffirm, revise, orwithdraw this standard. Purchasers of American National Standards mayreceive current information on all standards by calling or writing the AmericanNational Standards Institute.American National StandardPublished byAmerican Nati
11、onal Standards Institute, Inc.25 West 43rd Street, New York, NY 10036Copyright 2003 by Information Technology Industry Council (ITI)All rights reserved.No part of this publication may be reproduced in anyform, in an electronic retrieval system or otherwise,without prior written permission of ITI, 12
12、50 Eye Street NW, Washington, DC 20005. Printed in the United States of AmericaCAUTION: The developers of this standard have requested that holders of patents that may be re-quired for the implementation of the standard disclose such patents to the publisher. However, nei-ther the developers nor the
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16、cense that may be required to avoid infringement in the use ofthis standard.Copyright American National Standards Institute Provided by IHS under license with ANSINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-iContentsPageForeword iiIntroduction v1 Scope and Purp
17、ose 12 Normative References 23 Terms and Definitions. 24 General Information 55 Air Interface Protocol Specifications. 6Tables1 DSSS Link Parameters. 42 DSSS 56-Bit Message Format . 103 DSSS 72-Bit Message Format . 114 DSSS 88-Bit Message Format . 115 DSSS 152-Bit Message Format . 11Figures1 Example
18、 Differential Encoding Circuit 62 RTLS Transmitter PN Generator 73 RTLS Transmitter Data Encoding and Transmission Process . 74 DSSS Air Interface Protocol . 85 RTLS Transmitter State Diagram . 9Copyright American National Standards Institute Provided by IHS under license with ANSINot for ResaleNo r
19、eproduction or networking permitted without license from IHS-,-,-iiForeword (This foreword is not part of American National Standard ANSI INCITS 371.1-2003.)ANSI INCITS 371.1-2003 is one of a series of standards for Real Time Locating Sys-tems (RTLS) that provides in real-time the physical location
20、and the tracking of as-sets, human resources, or any other category of mobile items. This series ofstandards is intended to foster compatibility and interoperability of RTLS. There arethree standards in this series. Two airwave interface protocols are specified: one isdefined to provide a high-preci
21、sion system operating at 2.4 GHz and a second to pro-vide a lower-precision system operating at 433 MHz. A single Application Program-ming Interface (API) is defined that provides a unifying interface for either of the twoairwave interface protocols.Requests for interpretation, suggestions for impro
22、vement or addenda, or defect re-ports are welcome. They should be sent to InterNational Committee for InformationTechnology Standards (INCITS), ITI, 1250 Eye Street, NW, Suite 200, Washington,DC 20005.This standard was processed and approved for submittal to ANSI by INCITS. Com-mittee approval of th
23、is standard does not necessarily imply that all committee mem-bers voted for its approval. At the time it approved this standard, INCITS had thefollowing members:Karen Higginbottom, ChairJennifer Garner, SecretaryOrganization Represented Name of RepresentativeApple Computer, Inc. David Michael Wanda
24、 Cox (Alt.)Farance, Inc. Frank Farance Richard Lutz (Alt.)Hewlett-Packard Company. Karen Higginbottom Scott Jameson (Alt.)Steve Mills (Alt.)EIA Edward Mikoski, Jr. Judith Anderson (Alt.)Suan Hoyler (Alt.)IBM Corporation . Ronald F. Silletti Institute for Certification of Computer Professionals Kenne
25、th M. Zemrowski Thomas Kurihara (Alt.)IEEE . Judith Gorman Richard Holleman (Alt.)Robert Pritchard (Alt.)Intel Corporation. Gregory Kisor Dave Thewlis (Alt.)Microsoft Corporation . Mike Ksar Joseph Zajaczkowski (Alt.)National Institute of Standards less than 512 bits. 3.2.2.8 upconvert. A technique
26、to change a baseband signal to a higher frequency modulated signal for transmission. 3.3 Physical Layer Parameters For this standard, the following parameter definitions apply. These parameters are referenced by both the parameter number and the parameter name. 3.3.1 RTLS Transmitter DSSS Link Param
27、eters Table 1 DSSS Link Parameters Parameter number Parameter name Description D 1a Operating frequency range 24002483.5 MHz D 1b Operating frequency accuracy 25 ppm maximum D 1c Center frequency 2441.750 MHz D 2 Occupied channel bandwidth 60 MHz D 3 Transmit power Class 1: 10 dBm EIRP max. Class 2:
28、 Max per FCC part 15 D 4 Spurious emission, out of band Within FCC part 15 specification D 5 Modulation BPSK Direct Sequence Spread Spectrum (DSSS) D 6 Data encoding Differentially encoded D 7 Data bit rate 59.7 kbit/sec D 8 Bit error rate 0.001% D 9 PN chip rate 30.521875 MHz +/- 25 ppm D 10 PN cod
29、e length 511 D 11 PN spread code 0x1CB D 12 Data packet lengths Option 1: 56 bits Option 2: 72 bits Option 3: 88 bits Option 4: 152 bits D 13a Message CRC polynomial G(x)=X11 + X3 + X2 + X + 1 D 13b CRC polynomial initialized value 0x001 D 14a Blink interval Programmable, 5 sec. minimum D 14b Blink
30、interval randomization 638 milliseconds minimum D 15a Number of sub-blinks Programmable, 1 - 8 D 15b Sub-blink interval randomization 125 milliseconds 15 milliseconds D 16 Maximum Frequency Drift +/- 2 ppm over the duration of the entire message D 17a Phase Accuracy 0.5 radians within any 33 microse
31、cond period D 17b Phase Noise 15 degrees when the noise is integrated from 100hz to 100khz Copyright American National Standards Institute Provided by IHS under license with ANSINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-ANSI INCITS 371.1-2003 5 4 General Info
32、rmation 4.1 Frequency Range This standard addresses Real Time Locating Systems (RTLS) operating in the 2.400 to 2.4835 GHz fre-quencies. 4.2 Interface Definitions ANSI INCITS 371.1: 2.4 GHz Air Interface Protocol ANSI INCITS 371.2: 433 MHz Air Interface Protocol ANSI INCITS 371.3: The Common API for
33、 Interface between either 2.4 GHz or 433 MHz Band RTLS and Application Programs 4.3 Minimum Features The minimum feature set shall include: 2-dimensional location RTLS transmitters that autonomously generate a direct sequence spread spectrum radio fre-quency beacon Transmission at a power level that
34、 can facilitate reception at ranges of 300 meters open-field separation between the transmitter and receiver RTLS transmitters that are fully compliant with US radio frequency regulatory requirements Nominal location data provided by the RTLS that is within a 3-meter radius of the actual location of
35、 the transmitting RTLS transmitter when tested in open field. RF transmissions that are low power and that are compatible with, shall not interfere (not cause any measurable difference in throughput) and co-exist with existing standardized IEEE 802.11 wireless communication networks and systems comp
36、liant with ANSI INCITS 256. 4.4 Compliance Requirements To be fully compliant with this standard, Real Time Locating Systems (RTLS) shall also comply with ANSI INCITS 371.3. 4.5 Manufacturer Tag ID The manufacturers tag identification number identifies a particular manufacturer and consists of 16 bi
37、ts. A manufacturer may have more than one ID number. As reported from the RTLS Server to the API, the first 16 bits are designated for the manufacturers identification number. As reported from the Data Link Layer to the API, the remaining 16 bits establish a numbering system made unique by the initi
38、al manufac-turer ID number. The manufacturers identification number is a registration maintained by INCITS T20. Copyright American National Standards Institute Provided by IHS under license with ANSINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-ANSI INCITS 371.1-
39、2003 6 5 Air Interface Protocol Specifications ANSI INCITS 371.1 defines the 2.400- to 2.4835-GHz RTLS spread-spectrum transmissions and the command/data level air interface communication protocols. These protocols facilitate communication be-tween a compliant RTLS transmitter and a compliant infras
40、tructure. The timing parameters and signal characteristics for the protocols are defined in the physical link specification in clause 5.3. 5.1 Introduction A beacon type RTLS system architecture consists of RTLS transmitters that “blink” a Direct Sequence Spread Spectrum (DSSS) signal and fixed posi
41、tion RTLS readers that receive those signals. The system then determines the x, y location of the RTLS transmitters. Location of tagged assets can be determined with better than 3m accuracy in most environments, indoors and out. Once the location of the RTLS transmitter is determined, the location i
42、nformation and any other information is passed to the host applica-tion. Additionally, an option that provides the ability to transmit telemetry data is defined. 5.2 Functional Description The RTLS transmitter module is typically a compact internally powered radio frequency device that is a componen
43、t of the RTLS system. The RTLS system is designed to track and locate items with attached RTLS transmitters. Each locatable transmission is a pulse of direct sequence spread spectrum radio sig-nal. The RTLS infrastructure receives these signals, or blinks. The blink is a short ID-only message or a l
44、onger telemetry message also containing the RTLS transmitters ID. Each transmission also contains a status data word that provides information on the RTLS transmitter configuration, battery status and other data. The RTLS transmitters ID, status data word and location are provided to the host by the
45、 RTLS In-frastructure. Multiple RTLS transmitters may be present in typical installations allowing a large number of items to be tracked and located in real time. Anticollision synchronization protocols are not required. Each “blink” is comprised of multiple sub-blinks. The sub-blinks are part of a
46、multiple level antiinterference system; time diversity, spatial diversity, proc-essing gain. The combination of these multiple sub-blinks, multiple receiving antennas and spread spec-trum correlation also allow multiple RTLS transmitters to blink simultaneously and still be received. The RTLS transm
47、itter data shall be binary encoded with the MSB (Most Significant Bit) transmitted first in all messages. It is differentially encoded using the example circuit of Figure 1. The output of the encoder shall be initialized to 1. It shall be exclusively ORd with the output of the PN (Pseudo Noise) gene
48、rator, modulated using a BPSK (Bi-Phase Shift Keyed) format and upconverted using a single sideband upcon-verter. The signal is then amplified and transmitted to the RTLS infrastructure. QQSETCLRDData InData OutClockFigure 1 Example Differential Encoding Circuit An example of the RTLS Transmitter PN
49、 Generator is shown below in Figure 2. Copyright American National Standards Institute Provided by IHS under license with ANSINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-ANSI INCITS 371.1-2003 7 QQSETCLRDQQSETCLRDQQSETCLRDQQSETCLRDQQSETCLRDQQSETCLRDQQSETCLRDQQSETCLRDQQSETCLRDCBPN-Code1PN GeneratorOutputD1 D2 D3 D4 D5 D6 D7 D8 D9Figure 2 RTLS Tr
