linssid 2.9-3build1 (ppc64el binary) in ubuntu bionic

 LinSSID is a graphical program that displays locally receivable 802.11
 wireless attach points and ad hoc networks.
 .
 A table is displayed with various parameters such as MAC address, channel,
 and signal strength. Graphs are also displayed with signal strength by
 channel and signal strength over time.
 .
 LinSSID is graphically and functionally similar to inSSIDer (for Microsoft
 Windows) and Wifi Analyzer (for Android).
 .
 LinSSID can be used to measure the local performance or to search for an
 interference free channel to be set in a wireless router (access point or
 AP). The wireless established link won't be affected by these operations
 because LinSSID needn't set the monitor mode in network interface.
 .
 Some features:
 .
   - Table of locally receivable attach points with many columns of different
     information and sortable and movable columns.
   - Adjustable speed, real-time update.
   - Graphs of signal strength by channel and over time.
   - AP bandwidth displayed.
   - Works on both 2.4 GHz and 5 GHz channels.