/*

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

* All rights reserved.

* This component and the accompanying materials are made available

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

* which accompanies this distribution, and is available

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

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:   Declaration of the TWlanSignalPredictor class.

*

*/

/*

* %version: 7 %

*/

#ifndef WLANSIGNALPREDICTOR_H

#define WLANSIGNALPREDICTOR_H

#ifndef RD_WLAN_DDK

#include <wha_types.h>

#else

#include <wlanwha_types.h>

#endif

/**

 *  Signal Level Predictor machine.

 *

 *  @lib wlanumac.lib

 *  @since S60 v3.2

 */

class WlanSignalPredictor

    {

public:

    /**

     * Constructor.

     */

    WlanSignalPredictor();

    /**

     * Destructor.

     */

    inline ~WlanSignalPredictor();

    /**

     * Starts the Signal Predictor.

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

     * By default it is started.

     * @since S60 v3.2

     */    

    inline void Start();

    /**

     * Stops the Signal Predictor.

     *

     * @since S60 v3.2

     */    

    inline void Stop();

    /**

     * Configure the Signal Predictor operation.

     *

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

     * @since S60 v3.2

     * @param aTimeToWarnLevel Specifies the time (in microseconds)

     *        how far into the future signal prediction is done.

     * @param aTimeToNextInd The minimum time difference (in 

     *        microseconds) between two signal loss prediction indications.

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

     *        reached within the time specified by aSpTimeToCountPrediction,

     *        a signal loss prediction indication is sent. 

     */

    void ConfigureSignalPredictor( 

        TUint32    aTimeToWarnLevel,

        TUint32    aTimeToNextInd,

        WHA::TRcpi aRcpiWarnLevel );

    /**

     * Insert new rcpi information into the Signal Predictor.

     *

     * @since S60 v3.2

     * @param aTimestamp 32-bit timestamp in microseconds.  

     * @param aRcpi rcpi value from HW

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

     */

    TBool InsertNewRcpi( 

        TUint32    aTimestamp, 

        WHA::TRcpi aRcpi ); 

    /**

     * Get the latest median value from Signal Predictor.

     *

     * @since S60 v3.2

     * @param aTimestamp 32-bit timestamp in milliseconds.  

     * @param aLatestMedian reference to the median.

     * @return Boolean about if median value is available. 

     */

    TBool GetLatestMedian( 

        TUint32 aTimestamp,

        TUint8& aLatestMedian ) const;

    /**

     * Get the latest rcpi from Signal Predictor.

     *

     * @since S60 v3.2

     * @param aTimestamp 32-bit timestamp in milliseconds.  

     * @param aLatestRcpi reference to the rcpi.

     * @return Boolean about if rcpi value is available. 

     */    

    TBool GetLatestRcpi( 

        TUint32 aTimestamp,

        TUint8& aLatestRcpi );

protected:

    /**

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

     *

     * @since S60 v3.2

     * @param aTimestamp 32-bit timestamp in milliseconds.  

     */    

    void RemoveOldValues( 

        TUint32 aTimestamp );

    /**

     * removes an old value from rcpi table.

     *

     * @since S60 v3.2

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

     */    

    void RemoveValue( 

        TUint8 aIndex );

    /**

     * Inserts new median value into median table.

     *

     * @since S60 v3.2

     * @param aTimestamp 32-bit timestamp in milliseconds.  

     * @param aMedian a new median value.

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

     */    

    TBool InsertMedian( 

        TUint32 aTimestamp, 

        TUint8  aMedian );

    /**

     * Inserts new rcpi value into rcpi table.

     *

     * @since S60 v3.2

     * @param aTimestamp 32-bit timestamp in milliseconds.  

     * @param aRcpi a new rcpi value.

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

     */    

    TBool InsertValue( 

        TUint32    aTimestamp, 

        WHA::TRcpi aRcpi );

    /**

     * Count the current median from the rcpi table.

     *

     * @since S60 v3.2

     * @return Current median value. 

     */    

    TUint8 GetCurrentMedian() const;

    /**

     * Counts the estimation about the signal behaviour.

     *

     * @since S60 v3.2

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

     */    

    TBool GetPrediction();

    /**

     * Get the time interval between old and new times.

     *

     * @since S60 v3.2.

     * @param aOldTime 32-bit timestamp in milliseconds.

     * @param aNewTime 32-bit timestamp in milliseconds.

     * @return Time interval  in milliseconds.

     */    

    TUint32 Delay(

        TUint32 aOldTime, 

        TUint32 aNewTime ) const;

private:

    struct TValue  /* value info element */

        {

        TUint32    iTimestamp; /* timestamp */

        TUint8     iPrev;      /* next smaller rcpi value */

        TUint8     iNext;      /* next bigger  rcpi value */

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

        TUint8     iPad;       /* padding byte */

        };

    struct TLastRoam /* roaming info element */

        {

        TUint32 iTimestamp;/* timestamp */

        TBool   iDone;     /* valid or not */

        };

    /**

    * Only one iten

    */

    static const TUint KOneValue = 1;

    /**

    * Just dummy data pattern

    */

    static const TUint8 KDummy = 0x55;

    /**

    * Rcpi table size

    */

    static const TUint32 KValueCountMax = 25;

    /**

    * Median table size

    */

    static const TUint32 KMedianCountMax = 2;

    /**

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

    */

    static const TUint32 KValueDelay = 10;

    /**

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

    */

    static const TUint32 KMedianDelay = 35;

    /**

    * Window size in milliseconds

    */

    static const TUint32 KWindowSizeDefault = 1000;

    /**

    * Time to indication sending in milliseconds

    */

    static const TUint32 KTimeToIndicationLevel = 1000;

    /**

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

    */

    static const TUint32 KTimeToNextIndication = 1000;

    /**

    * Rcpi level when signal loss prediction indication generated

    */

    static const TUint8 KRoamLevel = 80;

    /**

    * Rcpi level above which, the indication is not sent

    */

    static const TUint8 KDiffRoamLevel = 120;

    /**

    * Minimum count of rcpi values to get signal loss prediction

    */

    static const TUint8 KMinValueCountForPrediction = 10;

    /**

    *  rcpi table 

    */

    TValue iLevelTable[ KValueCountMax ];

    /**

    *  median table 

    */

    TValue iMedianTable[ KMedianCountMax ];

    /**

    *  time interval to the indication level in milliseconds 

    */

    TUint32 iTimeToWarnLevel;

    /**

    *  observation time interval in milliseconds 

    */

    TUint32 iWindowSize;

    /**

    *  minimum time interval between two signal loss prediction 

    *  indications, in milliseconds 

    */

    TUint32 iTimeToNextInd;

    /**

    *  level when roam indication in generated 

    */

    TUint8 iWarningLevel;

    /**

    *  rcpi count in the rcpi table 

    */

    TUint8 iValueCount;

    /**

    *  median count in the median table 

    */

    TUint8 iMedianCount;

    /**

    *  index of the latest median item in the median table 

    */

    TUint8 iLatestMedian;

    /**

    *  index of the latest rcpi item in the rcpi table 

    */

    TUint8 iOldestValue;

    /**

    *  index of the latest rcpi item in the rcpi table 

    */

    TUint8 iLatestValue;

    /**

    *  index of the least rcpi item in the rcpi table 

    */

    TUint8 iLeastRcpi;

    /**

    *  index of the biggest rcpi item in the rcpi table 

    */

    TUint8 iMaxRcpi;

    /**

    *  Used value count, max value is KValueCountMax 

    */

    TUint8 iValueCountMax;

    /**

    *  Used value count, max value is KValueCountMax 

    */

    TUint8 iMinValueCountForPrediction;

    /**

    *  State information */

    TBool iRunning;

    /**

    *  Last signal loss prediction indication info 

    */

    TLastRoam iRoamed;

    };

#include "umacsignalpredictor.inl"

#endif // WLANSIGNALPREDICTOR_H