FUNCTION {{p}}tel_rate
  IMPORTING
    iv_ctype TYPE string
    iv_zone TYPE string
    iv_secs TYPE i
  EXPORTING
    ev_minutes TYPE i
    ev_charge TYPE decfloat34
  EXCEPTIONS
    invalid_duration.

  TYPES: BEGIN OF ty_price,
           ctype TYPE string,
           zone  TYPE string,
           price TYPE decfloat34,
         END OF ty_price,
         tt_price TYPE SORTED TABLE OF ty_price WITH UNIQUE KEY ctype zone.

  DATA lt_prices TYPE tt_price.
  DATA ls_price TYPE ty_price.

  IF iv_secs < 0.
    RAISE invalid_duration.
  ENDIF.

  IF iv_secs > 0.
    ev_minutes = ( iv_secs + 59 ) DIV 60.

    lt_prices = VALUE #(
      ( ctype = 'NT' zone = 'A' price = '0.09' )
      ( ctype = 'NT' zone = 'B' price = '0.19' )
      ( ctype = 'NT' zone = 'C' price = '0.29' )
      ( ctype = 'IT' zone = 'A' price = '0.19' )
      ( ctype = 'IT' zone = 'B' price = '0.39' )
      ( ctype = 'IT' zone = 'C' price = '0.59' )
      ( ctype = 'MO' zone = 'A' price = '0.29' )
      ( ctype = 'MO' zone = 'B' price = '0.49' )
      ( ctype = 'MO' zone = 'C' price = '0.69' )
      ( ctype = 'SP' zone = 'A' price = '0.39' )
      ( ctype = 'SP' zone = 'B' price = '0.59' )
      ( ctype = 'SP' zone = 'C' price = '0.79' ) ).

    READ TABLE lt_prices INTO ls_price
      WITH TABLE KEY ctype = iv_ctype zone = iv_zone.
    IF sy-subrc = 0 AND ls_price-price > 0.
      ev_charge = round( val = ev_minutes * ls_price-price + 0.025
                         dec = 2 mode = cl_abap_math=>round_half_up ).
    ENDIF.
  ENDIF.

ENDFUNCTION.