OsmocomBB

h1. RSSI application (firmware)

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This [[OsmocomBB]] firmware build is able to measure received signal strength over all channels that the hardware supports.

It has two modes: ARFCN view and Spectrum view.

Depending on your hardware capabilities, this firmware is able to take measurements in all four bands in both uplink and downlink.

Uplink measurements always require the [[HardwareFilterReplacement]].

h2. Loading procedure

RSSI is too big to be loaded directly, so it have to be chainloaded (using "-c" option), i.e. [[Osmocon]] first will load little [[Loaderbin]] binary, which in its turn will load actual payload (big RSSI binary).

The example chainloading command for a C123 phone:

<pre>

$ cd osmocom-bb/src/

$ host/osmocon/osmocon -p /dev/ttyUSB0 -m c123xor -c target/firmware/board/compal_e88/rssi.highram.bin

</pre>

h2. ARFCN view

{{thumbnail(osmocombb-rssi-arfcn.jpg)}} {{thumbnail(osmocombb-rssi-arfcn-color.jpg)}}

In the ARFCN view you get

* an indication of the ARFCN currently selected

* an indication of the band (DCS/PCS) for ARFCNs that exist in both bands

* the Rx Level in dBm

* a bar graph vor visualizing the RSSI

* an optional audible indication (beep tones) corellated with the RSSI

You can use it the following way:

* Enter the digits of an ARFCN on the numeric keypad followed by the Enter soft-key

* Use the Left/Right buttons to decrease/ increase the currently shown ARFCN

* Hold the Left/Right buttons to faster decrease / increase ARFCN 

* Use the Up/Down buttons to increase/decrease the beep tone volume

* Use the * (asterisk) button to enter or leave spectrum view

* Use the UL/DL soft-button to change uplink / downlink measurement

* Use Menu (middle) button to toggle maxium hold

* Press green button to sync to selected cell

h2. Spectrum view

{{thumbnail(osmocombb-rssi-spectrum.jpg)}} {{thumbnail(osmocombb-rssi-spectrum-color.jpg)}}

In the spectrum view, you get a graphical spectrum plot

You can use it the following way:

* Use the Up/Down buttons to adjust the scale

* Use the Left/Right buttons to decrease/ increase the currently shown ARFCN

h2. Sync view

{{thumbnail(osmocombb-rssi-sync-color.jpg)}}

In the Sync view you will received system information messages. Some of them are displayed, like network and cell ID.

You can use it the following way:

* Use the Down button to view ARFCNs of serving and neighbour cells

* Use the Up button to view received levels of each timeslot

* Use the Left/Right buttons to select ARFCN of serving cell to be monitored

* Press green button to request channel, to measure distance and delay

{{thumbnail(osmocombb-rssi-sync-distance-color.jpg)}}