/*
 ==========================================================================================
 ITU-T Telecommunications Standardization Sector      Document:   VCEG-M77
 Study Group 16 Question 6                            Filename:   radio_link_agent.h
 Video Coding Experts Group (VCEG)                    Generated:  02 July, 2001
 ----------------------------------------
 Thirteenth meeting: Austin, Texas, 2-4 April, 2001


 Intention: 
 ~~~~~~~~~~~~
 Simple offline software simulator for RTP/IP over 3GPP/3GPP2 bearers


 Source:
 ~~~~~~~
 Thomas Stockhammer, Guenther Liebl                  Tel:   +49 89 28923473
 Institute for Communications Engineering            Fax:   +49 89 28923490
 Munich University of Technology                     Email: {stockhammer,liebl}@ei.tum.de
 80290 Munich, Germany
 ==========================================================================================
*/


#ifndef RADIO_LINK_AGENT_H
#define RADIO_LINK_AGENT_H


#include "global.h"
#include "packet_data_agent.h"


// size of the radio link segemnt buffers
#define FRAME_BUFFER_SIZE 200


// retransmit delay in multiples of the transmission time interval
#define RETRANSMISSION_DELAY_FACTOR 1


// simulator-internal storage type for radio link agent SDUs
typedef struct virtual_sdu
{
  VIRTUAL_PDU upper_layer_PDU;
  int32 unsent_bytes;
  int32 received_bytes_counter;
  int32 correct_bytes_counter;
} VIRTUAL_SDU;


// new variable definition to indicate radio link frame type
typedef enum FrameType {DATA, RETRANSMIT, DUMMY} FrameType;


// storage type for information about the contained SDUs in a radio link frame
typedef struct contained_SDU_info
{
  int32 identifier;      // identifier of the contained SDU with respect to the SDU buffer
  int32 size;            // # of bytes from this SDU that are contained in the radio link frame
} CONTAINED_SDU_INFO;


// storage type for radio link frames
typedef struct radio_link_frame
{
  int32 sequence_number;
  int32 size;
  FrameType frame_type;
  int32 number_of_contained_SDUs;
  CONTAINED_SDU_INFO contained_SDU[PACKET_BUFFER_SIZE];
  int32 number_of_retransmissions;
} RADIO_LINK_FRAME;


// storage type for radio link retransmission queue
typedef struct retransmit_element
{
  RADIO_LINK_FRAME *retransmission_frame;
  int32 retransmission_time;
} RETRANSMIT_ELEMENT;








class RADIO_LINK_AGENT
{
 public:
  RADIO_LINK_AGENT();
  ~RADIO_LINK_AGENT();
  void initialize(FILE *ParameterFile_ptr, FILE *CommonLogFile_ptr, PACKET_DATA_AGENT *upper_layer_agent);
  Boolean send_frame(RADIO_LINK_FRAME **outgoing_frame);
  void receive_frame(RADIO_LINK_FRAME *incoming_frame, Boolean frame_error_indicator);
  void write_statistics(FILE *StatisticsFile_ptr); 

 private:
  void UM_receive_frame(RADIO_LINK_FRAME *incoming_frame, Boolean frame_error_indicator);
  void AM_receive_frame(RADIO_LINK_FRAME *incoming_frame, Boolean frame_error_indicator);

  char *ModuleName;

  FILE *LogFile_ptr;

  PACKET_DATA_AGENT *Upper_Layer_Agent;
  VIRTUAL_SDU SDU_Buffer[PACKET_BUFFER_SIZE];
  int32 SDU_buffer_read_position;
  int32 SDU_buffer_write_position;
  int32 SDU_buffer_total_length;          // total # of SDUs in the buffer for which the transmission process is not finished yet
  int32 SDU_buffer_unsent_length;         // # of SDUs in the buffer that still contain unsent parts

  int32 radio_bearer_bitrate;             // in kbit/s
  int32 frame_size;                       // in bits
  int32 agent_header_size;                // in bytes
  Boolean ACK_mode;                       // TRUE, if acknowledged mode is enabled
  Boolean fully_persistent_ARQ;           // TRUE, if acknowledged mode is fully-persistent
  int32 max_number_of_retransmissions;    // limit for non fully-persistent ARQ


  RETRANSMIT_ELEMENT Retransmit_Buffer[FRAME_BUFFER_SIZE];
  int32 Retransmit_buffer_read_position;
  int32 Retransmit_buffer_write_position;
  int32 Retransmit_buffer_length;


  int32 total_frames_counter;                      // contains the total number of frames (data, retransmitted and dummy)
  int32 total_retransmitted_frames_counter;        // contains the total number of retransmitted frames
  int32 total_dummy_frames_counter;                // contains the total number of dummy frames
  int32 total_correct_payload_bits_counter;        // contains the total number of correctly received data bits
  double total_bitrate;                            // total bitrate available (including radio link agent header)
  double total_net_bitrate;                        // total net bitrate available (excluding radio link agent header)
  double effective_net_bitrate;                    // effective net bitrate available (including only correctly received data bits)

  int32 transmission_time_interval;       // in ms, is computed from radio_bearer_bitrate and frame_size
  int32 simulation_time;                  // in ms, starting from 0
  int32 send_sequence_number;             // contains the sequence number for the next regular frame to be transmitted
  int32 receive_sequence_number;          // contains the sequence number for the next regular (not retransmitted) frame to be expected
};


#endif // RADIO_LINK_AGENT_H