The invention relates to an RDS radio unit implementing a user friendly algorithm for automatic frequency change without inconveniencing the user with interruptions. A timer is used to delay the start of searches for a better frequency. The RDS radio unit comprises: a radio tuner ( 2 ) tunable to radio frequencies; a control unit ( 3 ) capable of controlling the radio tuner and monitoring received signal strength on a frequency to which the radio tuner is tuned, a memory ( 4 ) for receiving and storing a list of alternative frequencies; a timer ( 5 ) capable of timing a number of operations. The control unit is adapted to perform a search for a better channel frequency than an original frequency with a program matching the original frequency only when a first time T 1 has elapsed, since the occurrence of an alternative frequency update request or a detection of received signal strength below a predetermined threshold. The present invention also relates to a telecommunication device ( 1 ) incorporating such an RDS radio unit.
1. An RDS radio unit comprising:
a radio tuner tunable to radio frequencies;
a control unit capable of controlling the radio tuner and monitoring received signal strength on a frequency to which the radio tuner is tuned,
storage means for receiving and storing a list of alternative frequencies;
timer means capable of timing a number of operations; wherein the control unit is configured to perform a search for a better channel frequency than an original frequency with a program matching the original frequency only when a first time T 1 has elapsed since the occurrence of an alternative frequency update request or a detection of a received signal strength below a predetermined threshold, and the received signal strength has not regained an acceptable value during T 1 ;
wherein the control unit is configured to perform the search during a second time T 2 by tuning the radio tuner through frequencies on the list of alternative frequencies, and
if a matching program is found, the radio tuner stays on the found channel frequency,
and if T 2 expires before a matching program is found, or if the end of the alternative frequencies list has been reached, the search through the alternative frequencies list is discontinued, and the control unit increments a counter to indicate the number of discontinued searches for alternative frequencies, the counter used to determine when to restart the search.
2. An RDS radio unit according to claim 1 , wherein the control unit is adapted to perform next search for a better channel frequency only when a third time T 3 has elapsed, if a search for a better channel frequency has failed once as indicated by the count of discontinued searches.
3. An RDS radio unit according to claim 2 , wherein the control unit is adapted to perform next search for a better channel frequency only when a fourth time T 4 has elapsed, if a search for a better channel frequency has failed more than once as indicated by the count of discontinued searches.
4. An RDS radio unit according to claim 3 , wherein T 1 <T 3 <T 4 .
5. An RDS radio unit according to claim 4 , wherein T 1 equals around 1 second, T 3 equals around one minute, and T 4 equals around ten minutes.
6. An RDS radio unit according to claim 4 , wherein T 2 is in the same range as T 1 .
7. An RDS radio unit according to claim 6 , wherein T 2 equals around 1 second.
8. A telecommunication device, comprising:
an RDS radio unit with a radio tuner tunable to radio frequencies;
a control unit capable of controlling the radio tuner and monitoring received signal strength on a frequency to which the radio tuner is tuned,
storage means for receiving and storing a list of alternative frequencies;
timer means capable of timing a number of operations; wherein the control unit is configured to perform a search for a better channel frequency than an original frequency with a program matching the original frequency only when a first time T 1 has elapsed since the occurrence of an alternative frequency update request or a detection of a received signal strength below a predetermined threshold, and the received signal strength has not regained an acceptable value during T 1 ;
wherein the control unit is configured to perform the search during a second time T 2 by tuning the radio tuner through frequencies on the list of alternative frequencies, and
if a matching program is found, the radio tuner stays on the found channel frequency,
and if T 2 expires before a matching program is found, or if the end of the alternative frequencies list has been reached, the search through the alternative frequencies list is discontinued, and the control unit increments a counter to indicate the number of discontinued searches for alternative frequencies, the counter used to determine when to restart the search.
9. A telecommunication device according to claim 8 , wherein the control unit is adapted to perform next search for a better channel frequency only when a third time T 3 has elapsed, if a search for a better channel frequency has failed once as indicated by the count of discontinued searches, and wherein the control unit is adapted to perform next search for a better channel frequency only when a fourth time T 4 has elapsed, if a search for a better channel frequency has failed more than once as indicated by the count of discontinued searches.
10. A telecommunication device according to claim 9 , wherein T 1 <T 3 <T 4 .
11. A telecommunication device according to claim 8 , wherein the device is a mobile telephone, a pager, a communicator, a smart phone, or an electronic organiser.