FAQ on BiDaE Products

Most frequent questions and answers

Currently, we offer the following products:

▪ BiDaE Indoor Positioning System
▪ BiDaE Object Tracker
▪ Seeing-I-Go APP

BiDaE Positioning System (BPS) is an open platform. It provides scalable, easy to deploy, enhance and maintain infrastructure support to indoor positioning and navigation and real-time object location/tracking applications and indoor location-based services in diverse venues, including hospitals, factories, transport hubs, and shopping malls. Its open interface enables the platform to provide indoor positioning support to not only our own navigation and object tracking applications, but also applications and services developed by customers and by other IT suppliers.

BiDaE Object Tracker (BOT) is a system of software tools for locating objects (including people and assets) and tracking their movements in real-time. BOT can be easily configured for use in smart hospitals, elderly homes and other care providing facilities. In addition to object location and tracking functions, BOT also offers tools designed to help users follow best practices in patient care and asset management. They do so by helping users monitor vital signs and movements of patients/residents and record notes on them, request repair service and record transfer of devices, generate shift change records, prevent theft or unintentional removal of objects, generate contact tracing reports, analyze and visualize asset usage data, provide statistics on rounding schedule adherence, and so on.

BOT can also be configured to serve industrial organizations: The current version can be used by manufacturing companies to monitor and track visitors, deliverers, customer representatives, interviewees, cleaning crews and security personnel in their office and factory building complexes. It also can be used in factories and processing plants to monitor workers for the purpose of ensuring their presence and enhancing their safety.

Seeing-I-Go (SIG) is a Bluetooth navigation app on smart phones. It can guide you within large buildings and outdoor spaces around buildings. Its distinguished features include the following: It
• Works in buildings without Google and similar indoor maps,
• Presents turn-by-turn directions in terms of simple spoken and visual instructions,
• Uses routes for you according to your preferences,
• Works with simple maps containing data on locations of destinations and pathways, traversable by persons on foot and wheelchairs connecting the destinations,
• Can warn you of obstacles ahead along your path, 
• Can use accessibility features of your smart phone as you wish.

The figure below illustrates the relationship among the products and some of the capabilities offered by them. Further information are provided by answers to questions follows.


The work performed by BPS platform is done collaboratively by two types of components: tags and location beacons (Lbeacons) as shown below. Both are low-cost Bluetooth devices.

Tags Each tag has a universally unique ID. BOT uses tags to make objects to be located and tracked visible to the system. This is done by having a tag attached to (or worn by) every object and storing in the server an association of the tag ID with the object ID/name.

BOT provides two types of tags: simple tags or sensor tags. Regardless its type, every tag broadcasts continuously packets containing its own ID and thus, advertises to Bluetooth receivers nearby its own presence and the presence of the object associated with it. This is all simple tags do.

Sensor tags contain sensors. In addition to its ID, each sensor tag also broadcasts readings of its sensor on a regular basis. In BOT serving hospitals and elderly homes, sensor tags usually are smart watches containing vital sign sensors. They broadcast readings of temperature, blood pressures, heart rates, and blood oxygen levels of their wearers once every 5-10 minutes. BOT uses this capability to support the remote vital sign monitoring function. Some sensor tags can provide readings of acceleration. BOT uses them to monitor movements of persons wearing them.

Lbeacons Location beacons, called Lbeacons for short, are Bluetooth transceivers. Some of them also provide gateway function to link Lbeacons nearby to the local WLAN. Lbeacons/gateways are pervasively installed throughout the area where objects are to be located and tracked. Lbeacons essentially work independently of one another. Each of them stores and broadcast its own 3D coordinates, scans its coverage area continuously and communicates via WiFi or Ethernet to the BPS server. When a Lbeacon hears a tag, it sends to the server the ID of the tag, its own 3D coordinates, and the time interval during which the tag is heard. It forwards to the server time stamped sensor readings of every sensor tag. Based on the data from all Lbeacons installed in the area covered by BOT, the server determines at any time the location of every tag and the time interval in which the tag has been at its location.

The horizontal location accuracy of BOT depends on the size of the coverage areas of individual Lbeacons and to a lesser extent on their density: Generally speaking, BOT aims to bring the user to within sight of sought-after objects: Lbeacons are configured to achieve no more than 3-5 meters or 5-10 meters horizontal accuracy. This is often referred to as bed-level/desk-level or room-level accuracy, respectively. In hospitals and other healthcare facilities, this configuration is typically used for areas such as emergency department and patient wards.

A BOT may be configured to provide zone-level accuracy (i.e., a lower location accuracy of 10-20 meters or more) in all or some areas. This setting is usually used when the goal is to determine whether the sought-after object is in the building, or on which floor, in which patient ward or which part of a ward. Because fewer Lbeacons are needed to cover areas  requiring zone level accuracy, the cost of BOT is reduced accordingly.

Again, the number of Lbeacons required depends on the required horizontal accuracy. As examples, the BOT currently installed in a part of the emergency department of approximately 1,800 square meters in a large teaching hospital uses 102 Lbeacons to achieve bed-level accuracy. A BOT providing room-level accuracy in a patient ward with 40 rooms requires approximately 50 Lbeacons/gateways. In other words, roughly one per room plus 2 at each entrance/exit for geo-fencing and one at each of locations of special interest (e.g., nurse station and storage room). On the other hand, 100 Lbeacons are sufficient to achieve varying room-level and zone-level accuracies as required to cover the emergency room and 7 patient wards within a mid-size hospital.

The nominal response time of searches and other interactive operations is 2 seconds. Current locations of moving objects are updated within 10 seconds. This near real-time tracking update rate is a design choice, as a tradeoff between real-time response and user experience: The delay is introduced by the low-pass filter used to eliminate as much as possible jitters, unpredictable and false object movements caused by unavoidable fluctuations and background noise in signals received by Lbeacons.

Lbeacons are powered either via AC line or PoE (Power over Ethernet). Simple tags runs on cell batteries that require replacement once every 6-8 months. Tools such as battery status indicator and low-battery alerts provided by BOT supports both impromptu battery replacement as needed and periodic replacement operations. Batteries of smart watches worn by patients/residents are recharged with help from their care providers who are recipients of low-battery alerts from BOT.

The BPS platform is structured as an IOT fog for sake of scalability, practically without limit in terms of number of Lbeacons (read more) . The list below contains reasons:

  1. Object tracker provides geofences and location monitors to enforce confinement of visitors to visiting areas and residents with infections to isolation areas.
  2. Each Lbeacon works at the edge to eliminate duplicates in object location data. Bay doing so, Lbeacons relieve the server of this CPU intensive work and significantly reduce of the volume of data to be transmitted to the server.
  3. Individual Lbeacons are connected via gateways, with each gateway serving only Lbeacons in its immediate vicinity.
  4. Each Lbeacon/gateway transmits data from Lbeacons via the WiFi network or Ethernet to the server on real-time priority basis, with time-critical data from Lbeacons at geo-fences at the highest priority and Lbeacons’ health reports at the lowest priority.
  5. The health of individual Lbeacons are monitored and reported to server on a regular basis, preventing effort in monitor and maintain them from growing with their number.

For BOT, the maximum demand and commitment BiDaE Technology encountered to date is 10,000 objects. However, according to numbers published in Wikipedia, large hospitals have a few thousand beds, including one in Taiwan with 4,000 beds. A BOT serving such hospitals must be able to locate and track a few 10’s of thousands of objects with acceptably small performance deterioration. BiDaE has kept this demand in mind and has designed BOT is to scale up unlimitedly for all practical purposes.

    In addition to making the underlying BPS platform scalable in Lbeacons, scalability of BOT in terms of number of objects tracked is also ensured by the structure and implementation of the BPS server. It is composed of a backend server and a frontend server linked by a database. The former processes the data from Lbeacons to extract information on timed locations and movements of tracked objects and place the information in the database. The latter responds to searches and commands from browser-based BOT user interfaces by retrieving the required information from the database. It uses a thread pool to process the input data highly concurrently in order to take advantage of logical/physical processors available in modern server hardware. By keeping the data in memory during processing, it prevents the database and database server from being the bottleneck.

BPS platform is designed not only for scalability in ways described above, but also to be highly dependable. Dependability is achieved by building the BPS server and storage unit (hereafter referred to collectively as the server) on a high availability architecture on the one hand, by enabling the remainder of the system to degrade gracefully on the other hand.

     Specifically, graceful degradation of BPS follows straightforwardly from the fact Lbeacons broadcast their own coordinates and collect UIDs of tags in their covered areas essentially independently of one another. When a Lbeacon failures, the system can rely on Lbeacons in its vicinity to provide degraded service. For example, in an area where Lbeacons are configured to provide bed (or room) level accuracy, location accuracy may degrade to room (or zone) level when one or more Lbeacons failed. To provide added dependability, Lbeacons automatically and continuously assess their own health during normal operation and their health reports are sent to the server periodically. Consequently, faulty and defective Lbeacons can be identified on a timely basis. Oftentimes their health can be restored remotely before failure occurs.

    Battery status of every tag tracked by the platform is monitored continuously. BOT uses this capability to support low-battery alerts, letting designated user knows whenever any tag is low on battery and thus preventing failures to find objects due to dead tag batteries. 

    Finally, BPS server is prevented from being a single point by building it on a high availability architecture. The design goal is to achieve equal or better availability that is typically required of hospital information systems (HIS), that is in the range of 99.95 to 99.99% availability.

The products listed at the beginning of this note are available as of mid-2021. The supporting software is being used internally to support BiDaE Technology’s own efforts in design, installation, debugging and quality assurance of systems. BPS API’s and SDK are ready for customers.

BiDaE Technology is confident that the purchasing and lease prices of its products and their maintenance cost are highly competitive. For further information on costs of products of your interest, please contact sales@bidae.tech.