/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */ /* * Copyright (c) 2009, 2010 MIRKO BANCHI * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation; * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * Author: Mirko Banchi */ #ifndef BLOCK_ACK_MANAGER_H #define BLOCK_ACK_MANAGER_H #include #include #include #include "ns3/packet.h" #include "wifi-mac-header.h" #include "originator-block-ack-agreement.h" #include "ctrl-headers.h" #include "qos-utils.h" #include "wifi-mode.h" #include "wifi-remote-station-manager.h" namespace ns3 { class MgtAddBaResponseHeader; class MgtAddBaRequestHeader; class MgtDelBaHeader; class MacTxMiddle; class WifiMacQueue; /** * \ingroup wifi * \brief Block Ack Request * */ struct Bar { Bar (); /** * Construct Block ACK request for a given packet, * receiver address, Traffic ID, and ACK policy. * * \param packet * \param recipient * \param tid * \param immediate */ Bar (Ptr packet, Mac48Address recipient, uint8_t tid, bool immediate); Ptr bar; Mac48Address recipient; uint8_t tid; bool immediate; }; /** * \brief Manages all block ack agreements for an originator station. * \ingroup wifi */ class BlockAckManager { private: BlockAckManager (const BlockAckManager&); BlockAckManager& operator= (const BlockAckManager&); public: BlockAckManager (); ~BlockAckManager (); /** * Set up WifiRemoteStationManager associated with this BlockAckManager. * * \param manager WifiRemoteStationManager associated with this BlockAckManager */ void SetWifiRemoteStationManager (Ptr manager); /** * \param recipient Address of peer station involved in block ack mechanism. * \param tid Traffic ID. * * \return true if a block ack agreement exists, false otherwise * * Checks if a block ack agreement exists with station addressed by * recipient for tid tid. */ bool ExistsAgreement (Mac48Address recipient, uint8_t tid) const; /** * \param recipient Address of peer station involved in block ack mechanism. * \param tid Traffic ID. * \param state The state for block ack agreement * * \return true if a block ack agreement exists, false otherwise * * Checks if a block ack agreement with a state equals to state exists with * station addressed by recipient for tid tid. */ bool ExistsAgreementInState (Mac48Address recipient, uint8_t tid, enum OriginatorBlockAckAgreement::State state) const; /** * \param reqHdr Relative Add block ack request (action frame). * \param recipient Address of peer station involved in block ack mechanism. * * Creates a new block ack agreement in pending state. When a ADDBA response * with a successful status code is received, the relative agreement becomes established. */ void CreateAgreement (const MgtAddBaRequestHeader *reqHdr, Mac48Address recipient); /** * \param recipient Address of peer station involved in block ack mechanism. * \param tid Tid Traffic id of transmitted packet. * * Invoked when a recipient reject a block ack agreement or when a Delba frame * is Received/Transmitted. */ void DestroyAgreement (Mac48Address recipient, uint8_t tid); /** * \param respHdr Relative Add block ack response (action frame). * \param recipient Address of peer station involved in block ack mechanism. * * Invoked upon receipt of a ADDBA response frame from recipient. */ void UpdateAgreement (const MgtAddBaResponseHeader *respHdr, Mac48Address recipient); /** * \param packet Packet to store. * \param hdr 802.11 header for packet. * \param tStamp time stamp for packet * * Stores packet for a possible future retransmission. Retransmission occurs * if the packet, in a block ack frame, is indicated by recipient as not received. */ void StorePacket (Ptr packet, const WifiMacHeader &hdr, Time tStamp); /** * \param hdr 802.11 header of returned packet (if exists). * * \return the packet * * This methods returns a packet (if exists) indicated as not received in * corresponding block ack bitmap. */ Ptr GetNextPacket (WifiMacHeader &hdr); bool HasBar (struct Bar &bar); /** * Returns true if there are packets that need of retransmission or at least a * BAR is scheduled. Returns false otherwise. * * \return true if there are packets that need of retransmission or at least a BAR is scheduled, * false otherwise */ bool HasPackets (void) const; /** * \param blockAck The received block ack frame. * \param recipient Sender of block ack frame. * \param txMode mode of block ack frame. * * Invoked upon receipt of a block ack frame. Typically, this function, is called * by ns3::EdcaTxopN object. Performs a check on which MPDUs, previously sent * with ack policy set to Block Ack, were correctly received by the recipient. * An acknowledged MPDU is removed from the buffer, retransmitted otherwise. */ void NotifyGotBlockAck (const CtrlBAckResponseHeader *blockAck, Mac48Address recipient, WifiMode txMode); /** * \param recipient Address of peer station involved in block ack mechanism. * \param tid Traffic ID. * * \return the number of packets buffered for a specified agreement * * Returns number of packets buffered for a specified agreement. This methods doesn't return * number of buffered MPDUs but number of buffered MSDUs. */ uint32_t GetNBufferedPackets (Mac48Address recipient, uint8_t tid) const; /** * \param recipient Address of peer station involved in block ack mechanism. * \param tid Traffic ID. * * \return the number of packets for a specific agreement that need retransmission * * Returns number of packets for a specific agreement that need retransmission. * This method doesn't return number of MPDUs that need retransmission but number of MSDUs. */ uint32_t GetNRetryNeededPackets (Mac48Address recipient, uint8_t tid) const; /** * \param recipient Address of peer station involved in block ack mechanism. * \param tid Traffic ID of transmitted packet. * \param startingSeq starting sequence field * * Puts corresponding agreement in established state and updates number of packets * and starting sequence field. Invoked typically after a block ack refresh. */ void NotifyAgreementEstablished (Mac48Address recipient, uint8_t tid, uint16_t startingSeq); /** * \param recipient Address of peer station involved in block ack mechanism. * \param tid Traffic ID of transmitted packet. * * Marks an agreement as unsuccessful. This happens if recipient station reject block ack setup * by an ADDBA Response frame with a failure status code. For now we assume that every QoS station accepts * a block ack setup. */ void NotifyAgreementUnsuccessful (Mac48Address recipient, uint8_t tid); /** * \param recipient Address of peer station involved in block ack mechanism. * \param tid Traffic ID of transmitted packet. * \param nextSeqNumber Sequence number of the next packet that would be trasmitted by EdcaTxopN. * \param policy ack policy of the transmitted packet. * * This method is typically invoked by ns3::EdcaTxopN object every time that a MPDU * with ack policy subfield in Qos Control field set to Block Ack is transmitted. * The nextSeqNumber parameter is used to block transmission of packets that are out of bitmap. */ void NotifyMpduTransmission (Mac48Address recipient, uint8_t tid, uint16_t nextSeqNumber, WifiMacHeader::QosAckPolicy policy); /** * \param recipient Address of peer station involved in block ack mechanism. * \param tid Traffic ID of transmitted packet. * * This method to set the number of packets waitin for blockAck = 0 since the receiver will send the blockAck right away */ void CompleteAmpduExchange (Mac48Address recipient, uint8_t tid); /** * \param nPackets Minimum number of packets for use of block ack. * * Upon receipt of a block ack frame, if total number of packets (packets in WifiMacQueue * and buffered packets) is greater of nPackets, they are transmitted using block ack mechanism. */ void SetBlockAckThreshold (uint8_t nPackets); /** * \param queue The WifiMacQueue object. */ void SetQueue (Ptr queue); void SetTxMiddle (MacTxMiddle* txMiddle); /** * \param bAckType Type of block ack * * See ctrl-headers.h for more details. */ void SetBlockAckType (enum BlockAckType bAckType); /** * \param recipient Address of station involved in block ack mechanism. * \param tid Traffic ID. * * This method is invoked by EdcaTxopN object upon receipt of a DELBA frame * from recipient. The relative block ack agreement is destroyed. */ void TearDownBlockAck (Mac48Address recipient, uint8_t tid); /** * \param sequenceNumber Sequence number of the packet which fragment is * part of. * \return true if another fragment with the given sequence number is scheduled * for retransmission. * * Returns true if another fragment with sequence number sequenceNumber is scheduled * for retransmission. */ bool HasOtherFragments (uint16_t sequenceNumber) const; /** * \return the size of the next packet that needs retransmission * * Returns size of the next packet that needs retransmission. */ uint32_t GetNextPacketSize (void) const; /** * \param maxDelay Max delay for a buffered packet. * * This method is always called by ns3::WifiMacQueue object and sets max delay equals * to ns3:WifiMacQueue delay value. */ void SetMaxPacketDelay (Time maxDelay); void SetBlockAckInactivityCallback (Callback callback); void SetBlockDestinationCallback (Callback callback); void SetUnblockDestinationCallback (Callback callback); /** * \param recipient * \param tid * \param startingSeq * * \return true if there are packets in the queue that could be sent under block ACK, * false otherwise * * Checks if there are in the queue other packets that could be send under block ack. * If yes adds these packets in current block ack exchange. * However, number of packets exchanged in the current block ack, will not exceed * the value of BufferSize in the corresponding OriginatorBlockAckAgreement object. */ bool SwitchToBlockAckIfNeeded (Mac48Address recipient, uint8_t tid, uint16_t startingSeq); /** * \param recipient * \param tid * * \return the sequence number of the next retry packet for a specific agreement * * Returns the sequence number of the next retry packet for a specific agreement. * If there are no packets that need retransmission for the specified agreement or * the agreement doesn't exist the function returns 4096; */ uint16_t GetSeqNumOfNextRetryPacket (Mac48Address recipient, uint8_t tid) const; /** * Checks if the packet already exists in the retransmit queue or not if it does then it doesn't add it again */ bool AlreadyExists (uint16_t currentSeq, Mac48Address recipient, uint8_t tid); /** * Remove a packet after you peek in the queue and get it */ bool RemovePacket (uint8_t tid, Mac48Address recipient, uint16_t seqnumber); /* * Peek in retransmit queue and get the next packet without removing it from the queue */ Ptr PeekNextPacket (WifiMacHeader &hdr, Mac48Address recipient, uint8_t tid, Time *timestamp); /** * This function returns true if the lifetime of the packets a BAR refers to didn't expire yet else it returns false. * If it return false then the BAR will be discarded (i.e. will not be re-transmitted) */ bool NeedBarRetransmission (uint8_t tid, uint16_t seqNumber, Mac48Address recipient); /** * typedef for a callback to invoke when a * packet transmission was completed successfully. */ typedef Callback TxOk; /** * typedef for a callback to invoke when a * packet transmission was failed. */ typedef Callback TxFailed; /** * \param callback the callback to invoke when a * packet transmission was completed successfully. */ void SetTxOkCallback (TxOk callback); /** * \param callback the callback to invoke when a * packet transmission was completed unsuccessfully. */ void SetTxFailedCallback (TxFailed callback); private: /** * \param recipient * \param tid * * \return a packet * * Checks if all packets, for which a block ack agreement was established or refreshed, * have been transmitted. If yes, adds a pair in m_bAckReqs to indicate that * at next channel access a block ack request (for established agreement * recipient,tid) is needed. */ Ptr ScheduleBlockAckReqIfNeeded (Mac48Address recipient, uint8_t tid); /** * This method removes packets whose lifetime was exceeded. */ void CleanupBuffers (void); void InactivityTimeout (Mac48Address, uint8_t); void OriginatorInactivityTimeout (Mac48Address, uint8_t); struct Item; /** * typedef for a list of Item struct. */ typedef std::list PacketQueue; /** * typedef for an iterator for PacketQueue. */ typedef std::list::iterator PacketQueueI; /** * typedef for a const iterator for PacketQueue. */ typedef std::list::const_iterator PacketQueueCI; /** * typedef for a map between MAC address and block ACK agreement. */ typedef std::map, std::pair > Agreements; /** * typedef for an iterator for Agreements. */ typedef std::map, std::pair >::iterator AgreementsI; /** * typedef for a const iterator for Agreements. */ typedef std::map, std::pair >::const_iterator AgreementsCI; /** * A struct for packet, Wifi header, and timestamp. * Used in queue by block ACK manager. */ struct Item { Item (); Item (Ptr packet, const WifiMacHeader &hdr, Time tStamp); Ptr packet; WifiMacHeader hdr; Time timestamp; }; /** * \param item * * Insert item in retransmission queue. * This method ensures packets are retransmitted in the correct order. */ void InsertInRetryQueue (PacketQueueI item); /** * This data structure contains, for each block ack agreement (recipient, tid), a set of packets * for which an ack by block ack is requested. * Every packet or fragment indicated as correctly received in block ack frame is * erased from this data structure. Pushed back in retransmission queue otherwise. */ Agreements m_agreements; /** * This list contains all iterators to stored packets that need to be retransmitted. * A packet needs retransmission if it's indicated as not correctly received in a block ack * frame. */ std::list m_retryPackets; std::list m_bars; uint8_t m_blockAckThreshold; enum BlockAckType m_blockAckType; Time m_maxDelay; MacTxMiddle* m_txMiddle; Mac48Address m_address; Ptr m_queue; Callback m_blockAckInactivityTimeout; Callback m_blockPackets; Callback m_unblockPackets; TxOk m_txOkCallback; TxFailed m_txFailedCallback; Ptr m_stationManager; //added++++++++ Callback m_originatorBlockAckInactivityTimeout; public: void SetOriginatorBlockAckInactivityCallback (Callback callback); }; } //namespace ns3 #endif /* BLOCK_ACK_MANAGER_H */