@type get_system_selection_preference_response() :: %{
  optional(:emergency_mode) => :off | :on,
  optional(:mode_preference) => [radio_interface()],
  optional(:roaming_preference) => roaming_preference(),
  optional(:network_selection_preference) => network_selection_preference(),
  optional(:acquisition_order) => [radio_interface()],
  optional(:registration_restriction) => registration_restriction_preference(),
  optional(:usage_settings) => usage_setting_preference(),
  optional(:voice_domain) => voice_domain_preference()
}

Preference settings for when a device selects a system

• :emergency_mode - :on if the device is in emergency mode, :off otherwise
• :mode_preference - a list of radio access technologies the device will try to use
• :roaming_preference - the device roaming preference
• :network_selection_preference - if the device will automatically select a network
• :acquisition_order - the order in which the device will try to connect to a radio access technology
• :registration_restriction - the system registration restriction
• :usage_settings - the modem usage preference
• :voice_domain_preference - the voice domain preference

@type home_network_report() :: %{mcc: char(), mnc: char(), provider: binary()}

Report from requesting the home network

@type network_selection_preference() :: :automatic | :manual

The networking selection preference

• :automatic - automatically select the network
• :manual - manually select the network

@type preference_change_duration() :: :power_cycle | :permanent

How long a system preference change should be applied

• :power_cycle - only remains active until the next power cycle
• :permanent - remains active through power cycles until changed by a client

@type radio_interface() ::
  :no_service | :cdma_1x | :cdma_1x_evdo | :amps | :gsm | :umts | :lte

The radio interface that is being reported

@type registration_restriction_preference() ::
  :unrestricted | :camped_only | :limited | non_neg_integer()

The network registration restriction preference

• :unrestricted - device follows the normal registration process
• :camped_only - device will camp on a network but not register
• :limited - device selects the network for limited service

This can also be integer value that is specified by the specific modem provider

@type rf_band_information() :: %{
  interface: radio_interface(),
  band: binary(),
  channel: integer()
}

Information about an radio interface band

@type roaming_preference() :: :off | :not_off | :not_flashing | :any

The roaming preference

• :off - acquire only systems for which the roaming indicator is off
• :not_off - acquire a system as long as its roaming indicator is not off
• :not_flashing - acquire a system as for which the roaming indicator is off or solid on - CDMA only.
• :any - acquire systems, regardless of their roaming indicator

@type serving_system_indication() :: %{
  :name => :serving_system_indication,
  :service_id => 3,
  :indication_id => 36,
  :serving_system_registration_state => serving_system_registration_state(),
  :serving_system_cs_attach_state => attach_state(),
  :serving_system_ps_attach_state => attach_state(),
  :serving_system_selected_network => network(),
  :serving_system_radio_interfaces => [radio_interface()],
  optional(:cell_id) => integer(),
  optional(:utc_offset) => Calendar.utc_offset(),
  optional(:location_area_code) => integer(),
  optional(:network_datetime) => NaiveDateTime.t(),
  optional(:roaming) => boolean(),
  optional(:std_offset) => Calendar.std_offset()
}

Required fields:

• :name - the name of the indication
• :service_id - the service id
• :indication_id - the indication id
• :serving_system_registration_state - the state of the registration status to the serving system
• :serving_system_cs_attach_state - the circuit-switched domain attach state
• :serving_system_ps_attach_state - the packet-switched domain attach state
• :serving_system_selected_network - the type of selected radio access network
• :serving_system_radio_interfaces - a list of radio interfaces currently in use

Optional fields:

• :cell_id - the id of the cell being used by the connected tower
• :utc_offset - the UTC offset in seconds
• :location_area_code - the location area code of a tower
• :network_datetime - the reported datetime of the network when connecting
• :roaming - if you are in roaming or not
• :std_offset - Calendar.std_offset() for daylight savings adjustment

@type set_system_selection_preference_opt() ::
  {:mode_preference, [radio_interface()]}
  | {:change_duration, preference_change_duration()}
  | {:roaming_preference, roaming_preference()}

The options to configure the system selection preference

• :mode_preference - which radio access technologies should the modem use
• :change_duration - the preference_change_duration() for the applied settings. The default is :permanent.
• :roaming_preference - the preferred roaming setting

@type signal_strength_report() :: %{
  rssi_reports: [%{radio: radio_interface(), rssi: integer()}]
}

Report from requesting the signal strength

@type usage_setting_preference() :: :unknown | :voice_centric | :data_centric

The modem usage preference setting

:unknown - device does not know the usage preference setting :voice_centric - the device is set for voice centric usage :data_centric - the device is set for data centric

@type voice_domain_preference() :: :cs_only | :ps_only | :cs_preferred | :ps_preferred

The voice domain preference setting

• :cs_only - circuit-switched (CS) voice only
• :ps_only - packet-switched (PS) voice only
• :cs_preferred - PS is secondary
• :ps_preferred - CS is secondary