EYE FAQ: Difference between revisions

EYE FAQ (view source)

Revision as of 15:00, 28 March 2023

339 bytes removed , 28 March 2023

→‎Which data TX Power (29th byte) provide?

Vytenis.kibildis

Administrators

1,667

edits

@@ Line 125: / Line 125: @@
   Source:https://wiki.teltonika-gps.com/view/EYE_SENSOR_/_BTSMP1#Protocol_description
-==== Which data TX Power (29th byte) provide? ====
+==== What is TX / RFU / Calibrated Power? ====
-  The power is Byte 29 of iBeacon protocol. Before firmware version 1.2.4 this byte was providing the data about configured TX value and was the same number as in the configuration of the sensor. From version 1.2.4 the changes were implemented and now this byte provides measured transmission Power in dBm at 1 or 0 meters from the beacon data, which is basically a calibration. These changes were made because the only way to estimate the distance to a beacon is based on measuring its signal strength. However, the Received Signal Strength Indicator (RSSI) value alone does not mean anything, because beacons can broadcast their advertising packets with different TX power. For example, a smartphone should report RSSIs in different ranges for two beacons located at the same distance from a user, but broadcasting with different TX power levels. To address this issue beacon advertising packets, in addition to payload with identifiers, also broadcast reference RSSI values were introduced. For iBeacon it's the RSSI at 1 meter and for Eddystone it's the RSSI at 0 meters. This way an application that tries to estimate a distance to a beacon knows what RSSI it should receive at a certain distance to a beacon. Then, using it together with the actual RSSI, apps can extrapolate a possible distance to a beacon
+  The TX power value - value of processors power output to antenna. Calibrated Power - in the Beacon protocol is a critical parameter that helps estimate the distance between a beacon and a receiving device. For example, this value is sent in Byte 29 of the iBeacon packet and is typically set to a predefined value in the sensor's configuration. It indicates the transmitting power of the beacon at a reference distance of 1 meter and is measured in decibels referenced to 1 milliwatt (dBm). RFU - Similarly to Calibarated Power, RFU is set for Eddystone protocols. The difference is iBeacon, the calibrated power is reference RSSI value that is the expected RSSI value at 1 meter from the beacon, while for Eddystone, it's the expected RSSI value at 0 meters. Currently Teltonika is providing beacons with pre-calibrated RSSI at 1m for iBeacon and RSSI at 0m for Eddystone that should be suitable for most use cases, however we plan to introduce user calibration in the future.
 ===<big>Other questions (Questions without category)</big>===