1 /*

     2 * Copyright (c) 2007-2008 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of the License "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description:   Declaration of the TWlanSignalPredictor class.

    15 *

    16 */

    17 

    18 /*

    19 * %version: 7 %

    20 */

    21 

    22 #ifndef WLANSIGNALPREDICTOR_H

    23 #define WLANSIGNALPREDICTOR_H

    24 

    25 #ifndef RD_WLAN_DDK

    26 #include <wha_types.h>

    27 #else

    28 #include <wlanwha_types.h>

    29 #endif

    30 

    31 /**

    32  *  Signal Level Predictor machine.

    33  *

    34  *  @lib wlanumac.lib

    35  *  @since S60 v3.2

    36  */

    37 class WlanSignalPredictor

    38     {

    39 

    40 public:

    41 

    42     /**

    43      * Constructor.

    44      */

    45     WlanSignalPredictor();

    46 

    47     /**

    48      * Destructor.

    49      */

    50     inline ~WlanSignalPredictor();

    51 

    52     /**

    53      * Starts the Signal Predictor.

    54      * If signal predictor is stopped, Start command will start it.

    55      * By default it is started.

    56      * @since S60 v3.2

    57      */    

    58     inline void Start();

    59 

    60     /**

    61      * Stops the Signal Predictor.

    62      *

    63      * @since S60 v3.2

    64      */    

    65     inline void Stop();

    66 

    67     /**

    68      * Configure the Signal Predictor operation.

    69      *

    70      * Note! If given param is 0, then old value remains.

    71      * @since S60 v3.2

    72      * @param aTimeToWarnLevel Specifies the time (in microseconds)

    73      *        how far into the future signal prediction is done.

    74      * @param aTimeToNextInd The minimum time difference (in 

    75      *        microseconds) between two signal loss prediction indications.

    76      * @param aRcpiWarnLevel If this RCPI level is predicted to be

    77      *        reached within the time specified by aSpTimeToCountPrediction,

    78      *        a signal loss prediction indication is sent. 

    79      */

    80     void ConfigureSignalPredictor( 

    81         TUint32    aTimeToWarnLevel,

    82         TUint32    aTimeToNextInd,

    83         WHA::TRcpi aRcpiWarnLevel );

    84 

    85     /**

    86      * Insert new rcpi information into the Signal Predictor.

    87      *

    88      * @since S60 v3.2

    89      * @param aTimestamp 32-bit timestamp in microseconds.  

    90      * @param aRcpi rcpi value from HW

    91      * @return ETrue if signal loss prediction indication should be sent

    92      */

    93     TBool InsertNewRcpi( 

    94         TUint32    aTimestamp, 

    95         WHA::TRcpi aRcpi ); 

    96 

    97     /**

    98      * Get the latest median value from Signal Predictor.

    99      *

   100      * @since S60 v3.2

   101      * @param aTimestamp 32-bit timestamp in milliseconds.  

   102      * @param aLatestMedian reference to the median.

   103      * @return Boolean about if median value is available. 

   104      */

   105     TBool GetLatestMedian( 

   106         TUint32 aTimestamp,

   107         TUint8& aLatestMedian ) const;

   108 

   109     /**

   110      * Get the latest rcpi from Signal Predictor.

   111      *

   112      * @since S60 v3.2

   113      * @param aTimestamp 32-bit timestamp in milliseconds.  

   114      * @param aLatestRcpi reference to the rcpi.

   115      * @return Boolean about if rcpi value is available. 

   116      */    

   117     TBool GetLatestRcpi( 

   118         TUint32 aTimestamp,

   119         TUint8& aLatestRcpi );

   120 

   121 protected:

   122 

   123     /**

   124      * Checks if there are too old values in rcpi table.

   125      *

   126      * @since S60 v3.2

   127      * @param aTimestamp 32-bit timestamp in milliseconds.  

   128      */    

   129     void RemoveOldValues( 

   130         TUint32 aTimestamp );

   131     

   132     /**

   133      * removes an old value from rcpi table.

   134      *

   135      * @since S60 v3.2

   136      * @param aIndex Index of rcpi to be removed from rcpi table.

   137      */    

   138     void RemoveValue( 

   139         TUint8 aIndex );

   140     

   141     /**

   142      * Inserts new median value into median table.

   143      *

   144      * @since S60 v3.2

   145      * @param aTimestamp 32-bit timestamp in milliseconds.  

   146      * @param aMedian a new median value.

   147      * @return ETrue if signal loss prediction indication should be sent

   148      */    

   149     TBool InsertMedian( 

   150         TUint32 aTimestamp, 

   151         TUint8  aMedian );

   152     

   153     /**

   154      * Inserts new rcpi value into rcpi table.

   155      *

   156      * @since S60 v3.2

   157      * @param aTimestamp 32-bit timestamp in milliseconds.  

   158      * @param aRcpi a new rcpi value.

   159      * @return ETrue if signal loss prediction indication should be sent

   160      */    

   161     TBool InsertValue( 

   162         TUint32    aTimestamp, 

   163         WHA::TRcpi aRcpi );

   164     

   165     /**

   166      * Count the current median from the rcpi table.

   167      *

   168      * @since S60 v3.2

   169      * @return Current median value. 

   170      */    

   171     TUint8 GetCurrentMedian() const;

   172     

   173     /**

   174      * Counts the estimation about the signal behaviour.

   175      *

   176      * @since S60 v3.2

   177      * @return ETrue if signal loss prediction indication should be sent

   178      */    

   179     TBool GetPrediction();

   180     

   181     /**

   182      * Get the time interval between old and new times.

   183      *

   184      * @since S60 v3.2.

   185      * @param aOldTime 32-bit timestamp in milliseconds.

   186      * @param aNewTime 32-bit timestamp in milliseconds.

   187      * @return Time interval  in milliseconds.

   188      */    

   189     TUint32 Delay(

   190         TUint32 aOldTime, 

   191         TUint32 aNewTime ) const;

   192 

   193 private:

   194    

   195     struct TValue  /* value info element */

   196         {

   197         TUint32    iTimestamp; /* timestamp */

   198         TUint8     iPrev;      /* next smaller rcpi value */

   199         TUint8     iNext;      /* next bigger  rcpi value */

   200         WHA::TRcpi iRcpi;      /* rcpi value */

   201         TUint8     iPad;       /* padding byte */

   202         };

   203 

   204     struct TLastRoam /* roaming info element */

   205         {

   206         TUint32 iTimestamp;/* timestamp */

   207         TBool   iDone;     /* valid or not */

   208         };

   209 

   210     /**

   211     * Only one iten

   212     */

   213     static const TUint KOneValue = 1;

   214 

   215     /**

   216     * Just dummy data pattern

   217     */

   218     static const TUint8 KDummy = 0x55;

   219 

   220     /**

   221     * Rcpi table size

   222     */

   223     static const TUint32 KValueCountMax = 25;

   224 

   225     /**

   226     * Median table size

   227     */

   228     static const TUint32 KMedianCountMax = 2;

   229 

   230     /**

   231     * Minimum time delay which is needed to accept next rcpi value

   232     */

   233     static const TUint32 KValueDelay = 10;

   234 

   235     /**

   236     * Minimum time delay which is needed to accept next median value

   237     */

   238     static const TUint32 KMedianDelay = 35;

   239 

   240     /**

   241     * Window size in milliseconds

   242     */

   243     static const TUint32 KWindowSizeDefault = 1000;

   244 

   245     /**

   246     * Time to indication sending in milliseconds

   247     */

   248     static const TUint32 KTimeToIndicationLevel = 1000;

   249 

   250     /**

   251     * Minimum time in milliseconds to next signal loss prediction indication sending

   252     */

   253     static const TUint32 KTimeToNextIndication = 1000;

   254 

   255     /**

   256     * Rcpi level when signal loss prediction indication generated

   257     */

   258     static const TUint8 KRoamLevel = 80;

   259 

   260     /**

   261     * Rcpi level above which, the indication is not sent

   262     */

   263     static const TUint8 KDiffRoamLevel = 120;

   264 

   265     /**

   266     * Minimum count of rcpi values to get signal loss prediction

   267     */

   268     static const TUint8 KMinValueCountForPrediction = 10;

   269 

   270     /**

   271     *  rcpi table 

   272     */

   273     TValue iLevelTable[ KValueCountMax ];

   274 

   275     /**

   276     *  median table 

   277     */

   278     TValue iMedianTable[ KMedianCountMax ];

   279     

   280     /**

   281     *  time interval to the indication level in milliseconds 

   282     */

   283     TUint32 iTimeToWarnLevel;

   284 

   285     /**

   286     *  observation time interval in milliseconds 

   287     */

   288     TUint32 iWindowSize;

   289 

   290     /**

   291     *  minimum time interval between two signal loss prediction 

   292     *  indications, in milliseconds 

   293     */

   294     TUint32 iTimeToNextInd;

   295     

   296     /**

   297     *  level when roam indication in generated 

   298     */

   299     TUint8 iWarningLevel;

   300     

   301     /**

   302     *  rcpi count in the rcpi table 

   303     */

   304     TUint8 iValueCount;

   305     

   306     /**

   307     *  median count in the median table 

   308     */

   309     TUint8 iMedianCount;

   310     

   311     /**

   312     *  index of the latest median item in the median table 

   313     */

   314     TUint8 iLatestMedian;

   315     

   316     /**

   317     *  index of the latest rcpi item in the rcpi table 

   318     */

   319     TUint8 iOldestValue;

   320     

   321     /**

   322     *  index of the latest rcpi item in the rcpi table 

   323     */

   324     TUint8 iLatestValue;

   325     

   326     /**

   327     *  index of the least rcpi item in the rcpi table 

   328     */

   329     TUint8 iLeastRcpi;

   330     

   331     /**

   332     *  index of the biggest rcpi item in the rcpi table 

   333     */

   334     TUint8 iMaxRcpi;

   335 

   336     /**

   337     *  Used value count, max value is KValueCountMax 

   338     */

   339     TUint8 iValueCountMax;

   340 

   341     /**

   342     *  Used value count, max value is KValueCountMax 

   343     */

   344     TUint8 iMinValueCountForPrediction;

   345 

   346     /**

   347     *  State information */

   348     TBool iRunning;

   349 

   350     /**

   351     *  Last signal loss prediction indication info 

   352     */

   353     TLastRoam iRoamed;

   354     };

   355 

   356 #include "umacsignalpredictor.inl"

   357 

   358 #endif // WLANSIGNALPREDICTOR_H