# An Overview of Indoor Positioning and Mapping Technology Standards
## 2 Related Work
### Standards for Indoor Positioning, Mapping and Navigation
#### 2.3.1 ISO/IEC RTLS  
The RTLS are systems with the ability to locate the position of a device anywhere in a defined space at any time. There are many situations and applications calling for RTLS. [PERSON] et al. [55] provided a comprehensive overview of the application and the development possibilities of RTLS in the manufacturing field. The ISO/IEC JTC 1/SC 31 (Joint Technical Committee 1, Information Technology Subcommittee) developed a series of international standards in the field of automatic identification and data capture techniques, including ISO/IEC 24730, ISO/IEC 24769, ISO/IEC 24770 and ISO/IEC 18305. Standard ISO/IEC 24730 defines a single application programming interface (API) and three air interface protocols for RTLS. Standard ISO/IEC 24730-1:2014 [56] provides an API which defines a boundary across which application software uses the facilities of programming languages to collect information contained in RTLS tag blinks received by the RTLS infrastructure and enables software applications to utilize a RTLS infrastructure to locate assets with RTLS transmitters attached to them. The other three air interface protocols are:  
1. Based on a direct sequence spread spectrum (DSSS), ISO/IEC 24730-2 defines a networked location system that provides X-Y coordinates and data telemetry, and it is comprised of this main document [57] and two additional components, that is ISO/IEC 24730-21:2012 [58], which specifies transmitters operating with a single spread code and employing a differential binary phase shift keying (DBPSK) data encoding and binary phase shift keying (BPSK) spreading scheme and ISO/IEC 24730-22:2012 [59], which specifies the air interface for a system that locates an asset in a controlled area. 2. Standard ISO/IEC 24730-5 [60], based on a chirp spread spectrum (CSS) technique, defines an air interface protocol which utilizes CSS at frequencies from 2.4 GHz to 2.483 GHz. This protocol supports bidirectional communication and two-way ranging between the readers and tags of an RTLS. 3. The ISO/IEC 24730-6 UWB air interface protocol is also comprised of two parts: ISO/IEC 24730-61:2013 [61] defines the physical layer (PHY) and tag management layer (TML) of an UWB air interface protocol that supports one directional simplex communication readers and tags of an RTLS that operate within the 6-10.6 GHz unlicensed band; and ISO/IEC 24730-62:2013 [62] defines the air-interface for RTLS using a physical layer UWB signaling mechanism (based on IEEE 802.15.4a UWB) with high rate pulse repetition frequencies (PRF) of 16 MHz or 64 MHz. Device conformance test methods are specified in ISO/IEC 24769, which consists of four parts, namely ISO/IEC 24769-2:2013 [63], ISO/IEC 24769-5:2012 [64], ISO/IEC 24769-61:2015 [65], and ISO/IEC 24769-62:2015 [66]. These standards contain the measurements required to be made on a product to establish whether it conforms to the corresponding part of ISO/IEC 24730, and to define the test methods for determining the conformance of RTLS tags or/and readers with the specifications given in the corresponding subclauses of ISO/IEC 24730-2, ISO/IEC 24730-5, ISO/IEC 24730-61, and ISO/IEC 24730-62, respectively. Test methods for measuring the performance of equipment compliant with ISO/IEC 24730 are specified by ISO/IEC 24770, which correspondingly consists of four parts, namely ISO/IEC 24770:2012 [67], ISO/IEC 24770-5 [68], ISO/IEC 24770-61:2015 [69], and ISO/IEC24770-62:2015 [70]. These standards define the test methods measuring the performance of equipment compliant with ISO/IEC 24730-2, ISO/IEC 24730-5, ISO/IEC 24730-6, and ISO/IEC 24730-62, respectively. On the other hand, ISO/IEC 18305:2016 [71] provides a standard methodology for evaluating indoor localization systems and detailed test and evaluation procedures, performance metrics, and scenarios for localization and tracking systems. [PERSON] et al.