Method for rapid optimal selection of alternative frequencies in a Radio Data System receiver

Technical field

0001The invention relates to a method for storing and sorting of alternative frequencies in an alternative frequency memory an RDS broadcast radio receiver according to the preamble of Claim 1. The invention also relates to an RDS radio receiver with PLL oscillator and alternative frequency memory according to the preamble of claim eleventh

State of the art

0002A absorbed. RDS (Radio Data System) signal used in wireless Programmaustrahlungen, for example, radio programs for travelers in a motor vehicle, which corresponding to a RDS car radio is equipped, for transmission various important information that helps the RDS car radio among other things, a variety of an undisturbed reception necessary operations autonomously and automatically performs, without, for example, a driver's attention the road away and manual entries at RDS car radio must perform.

0003The RDS signal is specified in the EBU specification DIN EN50067 and contains or transmits to the transmitter signal a currently on RDS car radio set broadcast radio station, hereinafter also mother frequency or short MF called, for example, an alternative frequency list which alternative frequencies (AF) of the currently tuned radio station contains. This AF are frequencies from other transmitters to a transmitter chain of the currently tuned radio station / -Programms belong. For example, all stations which radiate the broadcast program of NDR2.

0004According to the EBU specification DIN EN50067 these AF are either sent after a Method A or Method B. According to Method A is the frequency of the currently tuned Transmitter, for example, 92.1 MHz for NDR2, on top of the list and it is followed by a list of all possible AF for these Transmitter or this station chain, ie for example NDR2. At supra regional channels this list can be very long contain (to 25 AF) and also AF which current to the Location of the recipient no transmitter signal or even a transmitter signal a station with another radio program have, here, for example WDR3, depending on location.

0005According to Method B frequency pairs are indicated when the number the AF'en 25 exceeds or to denote frequencies transferred temporarily to other programs or other Regions belong. When the currently selected radio station NDR2 with the frequency is 92.1 MHz, so begins the Alternative frequency list by method-B for example as below:<dl tsize="5" compact="compact"><dt>92.1</dt><dd>94.1</dd><dt>92.1</dt><dd>96.2</dd><dt>92.1</dt><dd>94.6</dd><dt>...</dt><dd>...</dd><dt>etc.</dt></dl>

0006An adequate knowledge of the MF rising or falling Arrangement of AF'en allowed the distinction between original channels and neighboring transmitters in the alternative frequency list the RDS signal of the currently tuned station. is F1 the MF and F2 and F3 AF'en, then identifies a Arrangement F1 <F2 AF F2 as an AF to F1 with the same Program and an array F3> F1 denotes the AF F3 as AF a regional variant of MF F1. Here are OriginalSenderAddress such broadcasters, the exact same program radiate as the current station. neighboring stations are those which, in principle, the same broadcast program how radiate the current station, but temporarily, for example, at certain times, have some regional differences in program. neighboring stations belong to the same station chain and are, for example BR2 transmitter with regional program for Franken and BR2-stations Regional Programme for Upper Bavaria.

0007To differentiate the various broadcasters in accordance with different transmitter chain contains the RDS signal the currently set broadcast radio station in addition a program identification code signal, hereinafter PI code or shortly PI called. This is according to the EBU specification DIN EN50067 from 4 bodies charged 1. nibbling to 4. FIG. Nibble be called. The first nibble identifies the country, eg "D" for Germany or "F" France. The 2nd nibble identifies whether it is a supra regional, national or regional station is. This 2nd nibble contains so the distinction between the above-mentioned original and Neighboring transmitters. The 3rd nibble identifies the transmitter chain, eg "8" for NDR. The 4th nibbling distinguishes the respective Program on the broadcasting network, eg NDR 1, NDR 2, NDR3, NDR 4 etc. the broadcasting of the Norddeutscher Rundfunk NDR.

0008In poor signal or reception quality RDS car radio leads automatically a test of alternative frequencies (AF-test) and replaced if necessary to an alternative frequency, if there is a better signal or reception quality results. A better reception quality, for example, but not necessarily, by a higher field strength given. In fact, these effects mean as multipath (multipath) reception, Data error rate at the reception of the RDS signal or adjacent channel interference partially independent of the field strength of the received signal to infringe Reception quality. The best reception quality is the of a sum of all parameters that the reception quality reflect, such as field strength, Multipathempfang-field strengths, Data error rate, adjacent channel interference. This sum is possibly under variable weighting of the various Parameter formed and yields a value, which is a measure of the reception quality.

0009This weighting is for example, country-specific. So is for example in France, the modulation and the field strength very high, by multipath reception, however, the AF signal but with high disturbances afflicted, whereas the RDS signal low Data error rate is detected easily. get here For example, the data error rate lower weight. Thus, it may happen that an AF, which in the Appreciation only the third strongest field strength of the received Transmitter signal has, currently the best reception quality offers. Hereinafter referred to as "Best AF" that to the PI code belonging AF, which is currently selected for the Transmitter provides the best reception quality.

0010The RDS broadcast receiver manages the alternative frequencies known to him For example, in descending order with respect to the above-mentioned value for the reception quality different systems, taking into account additional information, so that upon degradation of the Reception of the current broadcast station possible can always be changed to a better quality AF.

0011This is an important criterion that the same AF Program broadcasting, as the currently selected radio station, since a change of the program is not allowed. Rather, despite different locations, for example, an RDS car radio in a moving motor vehicle, as long as possible once the user selected Program a transmitter chain for the site RDS radio receiver optimal quality be audible. For this purpose, the RDS broadcast receiver checks the PI code for a certain AF and compares the obtained PI code with that as current station. Is this review takes place, so this is hereinafter referred to as a PI "Examined PI" means. If the PI codes coincide, spoken "valid AF" hereinafter from a. If the PI codes do not match, then in subsequent spoke of a "forbidden AF".

0012When checking the PI code of the RDS broadcast receiver must briefly from the currently tuned frequency to the test or newly einzumessende and switch to be evaluated AF. to a unwanted volume jump or short change in the output by the RDS broadcast radio receiver via speakers low frequency signal to avoid, during the short changeover connected the speaker output mute, which subsequently is referred to as a "muting". After muting is, depending according to results of the audit of the PI code, either the revalued AF in the alternative frequency list to a site corresponding to the reception quality to the other in the list located signals sorted and the speaker output released again to the original frequency, or AF discarded and the speaker output on the original reactivated frequency or on the tested new AF speaker output is enabled again.

0013In addition, optional regionalization, ie. 2 Nibble the PI codes are evaluated or not. If the 2. nibbling to be evaluated, it is called a sogn. "Reg On-Mode". This has the advantage that one does not by mistake slips in a new regional program. The disadvantage However, may be that very few AF available and possibly at an unsuitable location no frequency change is possible to better receivable original sender. Of the Reception could completely cancel here. Therefore, it is in make of broadcasters poorly serviced environments necessary to switch off the evaluation of the second nibble, at least a station of the program chain continue to hear can, albeit with regional possibly different program. This mode is also referred to as "Reg.-off mode".

0014When in automatic scans the receivable frequencies for further AF are searched, so is a search stop signal, hereinafter referred to as "SL-Stop", and observes that, from the detected on a frequency field strength of a mid Vote a received station or whether it corresponds to a reception signal of a crosstalk from an adjacent channel Transmitter is. "SL-stop" thus refers to a Mid Vote detector. The signal "SL-Stop" is only issued, if the received station is properly tuned. This prevents a stop automatic scanning process on Frequencies, which will simply speaking of adjacent channels have signals. Namely, during the scanning process, namely a reception field strength recorded at a frequency, but This is not registered with the visits of the SL-stop signal, so no stop is at this frequency.

0015the administration of AF in the RDS broadcast radio receiver, the following systems are known from DE 40 39 117 C2, DE 41 06 161 C2 and EP 0 476 826 B1:<ul><li>The alternative frequency list contains the AF'en the station list the RDS signal of the currently set broadcast radio station. This AF are sorted by field strength and it gives the disadvantage that rapidly changing with the sender Landscapes This system often does not respond quickly enough can and, if the AF with the supposedly best field strength already has no reception or other subject to strong interference, such as crosstalk another station on an adjacent channel.</li><li>The alternative frequency list contains only AF whose program identification (PI code) is checked, that is, the program chain information (Program ID or PI code) of the respective AF is evaluated and the result is positive the comparison of the PI code of the AF tested with the PI code as current station as a "valid AF" in the List added. Thus, the alternative frequency list communicated only from a subset of all the transmitter side in the RDS signal AF. This system has the disadvantage that it on rapid change is not flexible enough in the transmission environment responding and possibly AF discards that short time later due of relocation would be valid again.</li><li>The alternative frequency list of AF, with their Content only case of quality losses of the currently tuned Radio station for the presence of a better alternative being checked. This system has the disadvantage that often a long period of time without receiving a station or very poor reception occurs, to the search for a is finished better alternative.</li></ul>

SUMMARY OF THE INVENTION, OBJECT, SOLUTION, benefits

0016It is an object of the present invention, an improved A method or an improved RDS broadcast receiver of the to provide above type available, which above the eliminate disadvantages and a function-oriented Reviewed memory organization with respect to the reception quality RDS alternative frequencies as preparation for fast Frequency change falls below specific quality criteria the set broadcast radio station permits.

0017This object is achieved by a program listed in claim 1 process and by an RDS radio receiver of the type described above the features characterized in claim 10 dissolved.

0018For this it is inventively provided that the alternative frequencies (AF) both an alternative frequency list of RDS signal of a currently set broadcast radio station as even from a long-term stored list under the program identification (PI) of the selected radio station as also from a landscape memory, the alternative frequency the (AF) with the currently tuned radio station contains identical, ie valid program identification (PI) and the moment receivable frequencies in the FM band is reflected, be seen that at all under a certain stored program identification (PI) alternative frequencies (AF) at least saved an additional indicator is, and that the or the additional indicator as Sorting criterion of Alternative Frequencies (AF) in the alternative frequency memory be used.

0019This has the advantage that a long-term preparation and Monitoring the quality of development potential in AF'en Moment of frequency change a fast, immediate and reliable jump on a well in this moment usable AF allows. The care of the AF memory from different Sources also keeps in shadowing or new always reliable and transmitter landscapes the right AF ready. The current reception landscape with respect to program and Station chains is directly mapped in the AF memory.

0020Preferable further developments of the method are in the Claims 2 to 10 will be described.

0021A particularly preferred embodiment is characterized in that the at least one additional indicator a first additional indicator is indicating, whether the alternative frequency (AF) to an original or neighboring area transmitter heard and / or a second additional Indicator is indicative of whether in the immediate past the program identification (PI) this alternative frequency (AF) has been confirmed, and / or a third additional Indicator is indicative of whether a temporary Forbidden alternative frequency (AF), ie for example, a unclear or not yet recognizable as right or wrong AF, has been released for a re-evaluation, and / or a fourth additional flag is indicative of how strong and the quality with which the alternative frequency (AF) in their last measurement was evaluated and / or a fifth additional Indicator is indicative of whether the AF currently is marked as currently prohibited AF.

0022The fifth additional indicator specifies the information that would not start by clearly wrong detected PI this AF may be. Furthermore, such AF'en of the constant are Review and reassessment by briefly Pouncing and evaluating the RDS signal exception, as this only pointless time would waste. Such a situation is, however, in the Generally only available regionally and progresses travel or with the movement of the RDS broadcast radio receiver to another regional area, the identification of AF as currently prohibited AF by a corresponding new transmission environment be outdated. For this reason, the third additional Indicator is provided, which allows a as currently banned marked AF yet again for Review and re-evaluation is allowed. However, as long review and reassessment still incorrect PI results, the marking remains in fifth indicator as "Currently prohibited AF" exist. However, once a check and revaluation results in a correct PI, is the in fifth indicator stored ban lifted and this AF again valid to AF.

0023The second additional feature has the advantage that information on be used in the recent past can and this information is not new by appropriate Kame and checking of the PI code must be calibrated. in this connection was the new at the moment due to better expected Reception quality to jumping and test before AF short Time already before a currently set AF and it is already the information in the second indicator stored, that this is a valid AF AF with checked PI code is. Before moving to this AF is thus no muting and Checking the PI code necessary when the second flag notifies that the PI code of the AF just recently confirmed ie these AF AF as valid with respect to the currently set broadcast radio station has been confirmed. Much more jumps of the RDS broadcasting receiver this new AF in this Case directly without muting.

0024There is an additional update of the AF list by obtained that the alternative frequencies in addition from current in scans detected AF are added and optional Moreover, every AF in a predetermined rhythm by time brief, imperceptible essentially measurements of SL-stop, Field strength and quality will be reassessed. stations without SL-stop are preferably with lowest value or in the lowest priority, so that they in the AF list at the end are all in the AF, which last as AF can be used. Here, the rhythm may in its Periodicity vary targeted.

0025An appropriate evaluation and sorting of AF is characterized obtained that the AF according to all their measured values ​​and additional Indicators are ranked, the best to the AF first place so as to retain required at a Step attempt as the most promising AF to be available.

0026For a quick and low-latency switch to an AF even in generally poor reception conditions, the Process preferably carried out in a reg-off mode, wherein marking original or neighboring transmitters without consideration remains.

0027A list of preferred care with treatment of the transmitter side designated as original AF is achieved in that the method is performed in a Reg.-on mode, wherein the original sender from the neighboring stations sorted and thus to be Favoured. This takes into account the original and the neighboring area transmission frequencies for selecting the best AF.

0028An always current AF list with an excellent score of expected reception quality is achieved in that the Calibration of AF or permanently depending on certain Quality thresholds of the currently tuned radio station takes place.

0029Appropriately, the calibration of AF'en is in addition always on arrival of new, unknown AF'en.

0030In a particularly advantageous development of the invention, Alternatively, each frequency in a predetermined, preferably varying rhythm by time-short, substantially imperceptible measurements of SL-stop, field strength and quality reassessed.

0031When an RDS broadcast receiver of the above-mentioned type of PLL is (Phase-locked-loop) - oscillator according to the invention a faster FPLL and the alternative frequency memory for each alternative frequency has at least one additional storage on for storing a first additional plate, which indicates whether the AF to an original or neighboring area transmitter heard a second additional indicator, indicating whether in the immediate past, the PI This AF is confirmed, a third additional indicator, indicating whether a temporarily prohibited AF has been released for a reassessment, an additional fourth Indicator, which indicates how strongly or with which Quality AF was evaluated at their last measurement, and / or a fifth additional indicator, which indicates whether the AF currently identified as prohibited AF is.

0032This has the advantage that a long-term preparation and Monitoring the quality development of possible AF at the moment changing frequencies, a fast and reliable allows jumping to a well at this moment still usable AF. The current reception landscape with respect to programming and broadcasting networks is directly mapped in the AF memory.

Brief Description of Drawing

0033The invention will be described with reference to Figure explained in more detail. This shows in a schematic representation, Alternatively, a preferred embodiment of a frequency memory an RDS radio receiver according to the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

0034The embodiment illustrated in the figure of an alternative frequency memory 100 of an RDS radio receiver according to the invention comprises 1 to N memory 10 for alternative frequencies. Each memory 10 has a memory 12 for a Value of the program identification PI (n) of the nth respective stored alternative frequency, possibly several more, not shown memory locations for other values ​​and a memory 14 for the frequency f (n) (f1, f11, f12, F13 ... F1M; f2, f21, f22, f23 ... F2M; ... FN, f N1, Fn2 fN3 ... FNM) of the n-th stored respective alternative frequency. Next presets include additional features ZTotal (n) (Z_ges1, Z_ges11... Z_ges1M; Z_GeS2, Z_ges21... Z_ges2M; ... Z_gesN, Z_gesN1... Z_gesNM), Which are each composed of additional Plate Z1 (n), Z2 (n), Z3 (s), Z4 (s) and / or Z5 (n) of the respective nth stored composed alternative frequency. This results, for example Z_ges1 {from Z1 (1) Z2 (1) Z3 (1) Z4 (1) Z5 (1)}.

0035Preferred components of an RDS radio receiver according to the invention are a fast PLL oscillator, in the subsequent FPLL called, with a jump time of about 1 ms, a Memory organization for mobile RDS receivers, such as Car radios, and an assessment and categorization process for alternative frequencies (AF) which ensures that the best AF is in the first position in the memory.

0036The AF lock, hereinafter referred to as AFSTOR, serves to Low AF from various sources and because of the FPLL is the possibility for continuous quality assessment the AF possibly with consideration of the original and / or Neighboring frequency identification and program identification (PI) -Prüfstatus given.

0037In most of Europe the AF, for example, after Method B sent. This makes an increasing array (AF1 <AF2) or a falling arrangement (AF1> AF2) recognized whether that AF the original program or a neighbor program transfers. This is an aid to sorting with regionalised programs with different PI 2nd nibbling or with temporarily different PI. Even are in no regionalisiertem program the rising / falling Sequence information on whether the called AF a of the currently selected frequency, hereinafter also Master frequency (MF) called immediately adjacent AF or one is with a greater distance and not to the receiving area MF connects.

0038By FPLL the evaluation tests are (verification and revaluation an AF) inaudible. This is evidenced by the following specification reached the FPLL: The phase detector permits Band limits jump (87.6 MHz to 107.9 MHz) in 1.5 ms. It is a time constant switching for fast settling of Parameter field strength and SL-stop provided. It is a closed circuit with automatic LOCK-IN in the usual manner provided. There is a mute circuit hörgerechte how will be described in more detail below.

0039All things are based on the vote on each best AF on the evaluation of all available AF in AF lock. The AF lock AFSTOR includes information to different Sources:<sl><li>selected a. AF from using the RDS signal of the transmitter signal AF lists of the selected station and</li><li>b. AF from the long-term memory under the valid PI of selected station as well</li><li>c. AF with valid PI from a memory, the moment the reflects receivable frequencies in the FM band (Landscape memory) and possibly additions by frequencies the currently added by searches (be recognized.</li></sl>

0040The assembly and maintenance make these three AF-Sources optimal frequency hopping to improve AF largely independent reception situations where using the RDS signal the currently tuned radio station no AF lists more receivable. The constant maintenance of these lists and the Consideration of an original and neighboring frequency identification ensures even at long AF lists for fast location of the strongest, valid AF or repetition rate.

0041This requires that the AF constantly a quality review are subjected, so that the order of AF in Store the sending country (receiving country) reflects. Each registered in AFSTOR below a certain PI Frequency obtained for evaluation and sorting additional Markings having the following contents:<sl><li>a. An indicator whether the AF an original or a neighboring area transmitter according to a list transmission method, as the above-mentioned method B or Evaluating the second nibble of PI-code signal in the RDS signal. </li><li>b. An indicator whether in the immediate past the PI of AF as a "valid AF", ie those PI of the current station, was confirmed. This is the case if the just for consideration AF short time before, for example, a few minutes up hours while maintaining quality, already a temporarily suspended AF was. had for this purpose They previously been tested for their PI code signal be, which has been recognized as "valid PI", otherwise this AF would not be approved as currently set AF been. This information in this indicator stored, so that when a renewed increase waived this AF on a re-examination of the PI code can be and this AF with the appropriate information in this indicator for a "valid PI" jumped immediately and without muting for an examination of the PI code becomes. The user gets the impression of a Uninterruptible reception of his favorite program and unaware of the frequency change.</li><li>c. An indicator whether a temporarily prohibited AF (Incorrect PI) has been released for a reassessment. As mentioned above, a received with the RDS signal Alternative Frequency list also contain one or more AF, which at the current location of the RDS broadcast radio receiver a transmitter signal with a different PI code have, as the master frequency. If this is the case, is this AF under an entry in a below Points." explained indicator as prohibited AF in. This makes the AF is to not constantly a possible change in the reception quality checked, since it anyway because of another program than the State Mother frequency as valid AF in question comes. Over time, however, changes the location of the RDS broadcast radio receiver and the situation at this AF may change to the effect that now may the "wrong channel" has disappeared and actually a station is received with "valid PI" (Eg overreach). To account for this after predetermined conditions the Prüfverbot by an entry in this indicator for this AF released so that again a test of PI and calibration of the revaluation of the reception quality relevant parameters, such as SL-stop and Field strength occurs. If necessary, is at "valid PI" then the lower." amended accordingly explained indicator, if a "valid PI" is registered. This Indicator thus indicates whether a release condition occurred is. A "predetermined condition" could, for example, be a timing or a reception quality a currently set MF or AF is very bad, then good again. This shows, for example, in that the RDS broadcast radio receiver in a new Reception area is where the new calibration (Check and re-evaluating) were hitherto banned AF again might be worth.</li><li>d. A marking how much, or what quality AF was evaluated at its last measurement. This results advantageously a major sort criterion for AF in AFSTOR.</li><li>e. An indicator as to whether prohibitions or restrictions of a be long-term monitoring. This indicator be for the "c." described case added features, these AF as prohibited or unclear AF featuring, for example, in case of multiple registration a false PI codes with respect to the currently set Transmitter, although, for example, according to alternative frequency list from the RDS signal from the currently set Transmitter this AF an alternative frequency with would be valid PI, or on the AF is a NON-RDS stations recognized.</li></sl>

0042Through constant, inaudible evaluation of all currently not (Not included) to the speakers connected AF finds a continuous determination of the reception quality of the respective AF instead and then find an appropriate Sorting instead of the AF order in AFSTOR.

0043The resulting dynamics of AFSTOR is such that:<ul><li>in a rhythm vary its periodicity targeted may, each AF a reassessment by extremely short duration, largely imperceptible measurements of SL-stop, field strength and quality is subjected to</li><li>the AF are sorted according to their measurements, the best AF, ie with the best reception quality calculated at the 1 out so as to retain at a necessary step attempt to stand as the most promising AF available</li><li>in Reg-Off mode, the label original or neighboring stations excluding remains,</li><li>in Reg-on fashion the original sender in the front of the AFSTOR Neighboring transmitters sorted and are thus preferred,</li><li>the calibrations of AF continuously or depending certain quality thresholds the included transmitter (which in necessities AF change the current situation description based on the transmission environment guarantees), or additionally always done on arrival of new, unknown AF.</li></ul>

0044Targeted variation of the periodicity ensured thereby following: The human ear has the peculiarity that actually usually not perceived noise then deliberately perceived or bothersome when this noise some have a kind of periodicity. A mute circuit for calibration of AF with fixed periodicity could therefore worst case cause the actually usually unaware perceived mutes, the muting, the periodicity disturbance perceived to be. A targeted, in particular non-periodic Change the periodicity avoids this effect effective.

0045If a predetermined ratio of the reception of the current belonged or broadcast station to the calculated fulfills reception quality of the AF in AFSTOR, then there is a Jump condition before and there is the detachment of a concerted Reception frequency MF by the example in the first Place in AFSTOR standing AF. This sucked. Bestsprungbedingung For example, satisfied if the calculated Reception quality a higher evaluation value than the Reception quality of the master frequency. It may additionally comprise a Minimum improve the reception quality may be predetermined, ie the evaluation value of the reception quality of the AF in AFSTOR has to be at least a predetermined amount greater than the evaluation value of the reception quality of the currently tuned Transmitter.

0046The new AF may be chosen only (replaces the previous MF) if the MF below a certain reception quality and the best (1 AF) improves reception be expected.

0047This means that the AF has a minimum quality, depends on whether the AF has been tested-PI with success (Marking in AFSTOR) and whether the car radio in Gov. Off mode is operated. In Reg.-off mode is the minimum qualification regardless of the original, or neighboring area marking and is limited only by the labeling "PI already examined" influences. This need AF, the already successfully tested PI were lower qualifications, than those who do not, such labeling have. In particular, already "PI-tested" AF at a step attempt set ungemutet while AF, the will not bear this, "muted" jump.

0048In Reg.-on fashion the qualifying conditions described are first to the "original channels" (are, in AFSTOR neighboring transmitters sorted) applied. If, despite poor reception quality of MF no Reviewed sufficiently well Original-AF is available, it can also Neighbour Zone AF be started, provided that such a reached minimum qualification that a fast PI recognition be expected. This minimum qualification is however higher than in the original AF. When changing to such AF'en but must prove identical to the PI code.

0049The minimum qualification for MF and AF are programmable through Threshold values ​​for the parameters mentioned above, which the reception quality characterize, say for example Field strength, data error rate, Multipathempfang etc., in a non-volatile memory and changeable in various Situations, if necessary, as mentioned above, from country to country and Considering the signal path quality adaptable. An AF-AC for example, also be executed if the MF RDS reception quality threshold not below, but a significantly higher scores in AF AFSTOR available is, but in the case of the reg-on fashion a "Original" must wear identifier.

0050Deviating are advantageously "Special Conditions" for Bestsprünge at Frequenzneueinstellungen (Station buttons call) or in extremely bad reception conditions provided for the MF. After a station call or a frequency change by search is not only AF, as the abovementioned first AF in AFSTOR, tested, but a number "n" with a minimum quality of the pool of AF. The number "n" is programmable and non-volatile stored. One uses here prolonged Mute times at Frequency settings, eg keystrokes occur anyway and do not interfere because they are expected by the user.

0051While all standard AF drafts payable to AF with identical carried PI is also at Frequenzneueinstellungen in Reg On-Mode basically wanted an AF with an identical PI. It but also, as long as no corresponding AF receivable is AF with similar PI, as a deviation in the second nibble, admitted.

0052AF'en the moment are occupied by prohibitions or restrictions be upon exceeding a minimum rating, according to station call or in emergency situations (in extremely bad reception) readmitted. Through programmable control entries in a non-volatile memory is determined whether the AF according to their previous entries as "already successfully PI tested "first muted and tested directly or ungemutet be adjusted and without re-examining the PI codes allowed.

0053After a station call, and the PI-examination of "n" -AF everyone else in the store located AF initially as "Neighboring stations" on this day. Give these AF by means of a received RDS signal, for example at Neuempfang the AF list to recognize again as original transmitter, the corrected entry immediately and AF preferred accordingly.