High-Density and De-Densified Smart Campus Communications. Daniel Minoli
Чтение книги онлайн.

Читать онлайн книгу High-Density and De-Densified Smart Campus Communications - Daniel Minoli страница 19

СКАЧАТЬ or worldwide). These signals are typically electromagnetic: RF systems are common, but some systems use optical/infrared mechanisms (other signals can also be used in confined spaces). Position is derived by measurements of the physical properties of the radio link.

      Automatic wireless monitoring is prevalent in a variety of industries, where location and other characteristics of a product or environment must be tightly monitored for safety or regulatory reasons, such as hospitals; other environmental parameters may be significant due to the nature of the items or processes (e.g. manufacturing processes) monitored. Factors such as humidity, exposure to light, motion sensors, positional location within a predetermined area, and orientation of the product (e.g. whether or not it is upright) may be important. RTLSs have thus gained popularity and are now seen as a “mainstream product” [48]; these systems are especially popular in the healthcare industry for applications ranging from asset tracking through patient and staff tracking, environmental or patient sensing (e.g. temperature), hygiene compliance, elopement (i.e. a patient leaving a facility without authorization), and theft prevention. They also have applications in de‐densification of the office for OSD/ODCMA use cases.

      Conceptually, there are four classifications of RTLS [49]:

       Locating an asset in a controlled area, e.g. warehouse, campus, airport – area of interest is instrumented – accuracy to 10 ft;

       Locating an asset in a very confined area – area of interest is instrumented – accuracy to tens of centimeters;

       Locating an asset via satellite – requires Line‐of‐Sight (LOS) – accuracy to 30 ft;

       Locating an asset over a terrestrial area using terrestrial mounted receivers over a wide area, cell phone towers, for example – accuracy 600 ft.

Schematic illustration of a pictorial view of an RTLS environment. Schematic illustration of generic RTLS system concept.

      The method of location is through various types of multilateration, including:

       Angle of Arrival

       Time Difference of Arrival

       Time of Flight Ranging Systems

       Amplitude Triangulation

       Cellular Triangulation

       Satellite Multilateration (for GPS)

      When RFID tags are used, two methods of locating an object or people wearing a tag include:

       Locating an asset given that the asset has passed point A at a certain time and has not passed point B;

       Locating an asset by providing a homing signal whereby a person with a handheld can find an asset.

      These approaches are discussed later, starting in Chapter 6.

      1.3.2 Heuristic Density for the Pandemic Era

      

Schematic illustration of de-densified (heuristic model).

      This SuperNetwork СКАЧАТЬ