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The FXM domain

The FXM domain covers Fixed (FX), Mobile (M), and other services, such as aeronautical. With one exception (certain shortwave broadcasting bands), the FXM domain does not involve broadcasting. The FXM domain also covers various Plans (such as Appendices 25, 26, and 27) as well as the common frequencies that are reserved for specific purposes, such as emergency or distress use.

There is a separate domain for FXM notices, assignments, and allotments because they generally cover both transmitting and receiving locations. (The LF/MF and FM/TV domains consider only transmitting locations.) Therefore, the FXM database structure is quite different, and more complex, because of this requirement.

In the context of GE06, there is the concept of “other primary services” (OPS), meaning the non-broadcasting primary services within the scope of GE06. The OPS are contained within the FXM domain.

The FXM database tables are:

FXM

These FXM database tables implement the following conceptual structure for transmitting stations:

FXM2

For receiving stations, the conceptual structure is basically the same, if the positions of the transmitting and receiving sites are reversed.

Each notice, assignment, allotment, or common frequency has a row in the fxm_terra table. Each operation has a row in the fxm_ant table.

Integrate HAPS into FXM structure​

The database has been expanded to support High Altitude Platform Stations (HAPS) with the introduction of several new tables and columns.

New Tables for HAPS Integration:​

  • fxm_haps_attr: This table stores extra attributes specific to HAPS like the planned tolerance of HAPS coordinates, link direction (Uplink or Downlink), etc.
  • fxm_haps_ant: This table stores extra attributes about HAPS antennas, including their technical specifications.
  • fxm_haps_gain_contour and fxm_haps_gain_contour_pt: These tables contain data on the gain contours of HAPS antennas. Each entry in fxm_haps_gain_contour corresponds to a contour for a given gain.
  • fxm_haps_ant_diag: This table records the measured radiation pattern of the HAPS antenna, applicable when the antenna reference value (2.9.j) for the antenna is set to 'MEASURED'.
  • fxm_haps_rx_ant_diag: This table records the measured radiation pattern of the associated receiving ground station, applicable when the antenna reference value (3.9.j) for the ground station is set to 'MEASURED'.
  • fxm_haps_tx_ant_diag: This table records the measured radiation pattern of the associated transmitting ground station, applicable when the antenna reference value (3.9.j) for the ground station is set to 'MEASURED'.

New Columns Added:​

  • fxm_rx.ground_ant_ref: A new column in the fxm_rx table. Holds the reference radiation pattern of the associated receiving ground station (3.9.j).
  • fxm_tx.ground_ant_ref: A new column in the fxm_tx table. Holds the reference radiation pattern of the associated transmitting ground station (3.9.j).