This is the control unit for a Routemaster system, that downloads traffic information for the area local to the vehicle.
Here is an overview of the unit, in it’s aluminium box.
Here is the unit with the top cover removed, showing the pair of PCBs. The bottom PCB is the main control PCB, the top one holds an IC similar to a SIM card & part of the radio.
Here is the main PCB removed from the casing, contains the program ROM & microcontroller. for the system
Daughtercard view. This holds another programmed CPLD, the custom SIM-like IC & the RTC battery, along with some power conversion circuitry.
This is the radio receiver, looks to be AM, the large loop antenna can be seen at the bottom of the box.