From e43970ad50ee67dc3c795ed619a61b55f0fc6bc3 Mon Sep 17 00:00:00 2001 From: DJ2LS <75909252+DJ2LS@users.noreply.github.com> Date: Tue, 29 Dec 2020 11:10:02 +0100 Subject: [PATCH] ARQ Go-Back-N ARQ Go-Back-N now working even if frames are odd to frames per burst. --- arq.py | 165 +++++++++++++++++++++++++++++++++++++++------------------ 1 file changed, 113 insertions(+), 52 deletions(-) diff --git a/arq.py b/arq.py index c6a70eb8..887e1c94 100644 --- a/arq.py +++ b/arq.py @@ -18,59 +18,62 @@ import modem import other - modem = modem.RF() + crc_algorithm = crcengine.new('crc16-ccitt-false') #load crc16 library static.ARQ_PAYLOAD_PER_FRAME = static.FREEDV_PAYLOAD_PER_FRAME - 6 -#class ARQ(): -# -# def receive(bytes_in): -# -# print("TEST") def data_received(data_in): - ARQ_N_RX_BURSTS = int.from_bytes(bytes(data_in[:1]), "big") - 10 - static.ARQ_RX_BUFFER.append(data_in) #append data to RX BUFFER - - if len(static.ARQ_RX_BUFFER) == ARQ_N_RX_BURSTS: #if received bursts are equal to burst number in frame + ARQ_N_RX_BURSTS = int.from_bytes(bytes(data_in[:1]), "big") - 10 + static.ARQ_RX_BUFFER.append(data_in) #append data to RX BUFFER + + print(ARQ_N_RX_BURSTS) + + + + + #while static.ACK_RX_TIMEOUT == 0: #define timeout where data has to be received untl error occurs + + if len(static.ARQ_RX_BUFFER) == ARQ_N_RX_BURSTS: #if received bursts are equal to burst number in frame - burst_total_payload = bytearray() - for n_raw_frame in range(0,len(static.ARQ_RX_BUFFER)): + burst_total_payload = bytearray() + for n_raw_frame in range(0,len(static.ARQ_RX_BUFFER)): - burst_frame = static.ARQ_RX_BUFFER[n_raw_frame] #get burst frame - burst_payload = burst_frame[3:] #remove frame type and burst CRC - burst_total_payload = burst_total_payload + burst_payload #stick bursts together + burst_frame = static.ARQ_RX_BUFFER[n_raw_frame] #get burst frame + burst_payload = burst_frame[3:] #remove frame type and burst CRC + burst_total_payload = burst_total_payload + burst_payload #stick bursts together - print(burst_total_payload) - burst_payload_crc = crc_algorithm(burst_total_payload) - burst_payload_crc = burst_payload_crc.to_bytes(2, byteorder='big') - print(burst_payload_crc) + print(burst_total_payload) + burst_payload_crc = crc_algorithm(burst_total_payload) + burst_payload_crc = burst_payload_crc.to_bytes(2, byteorder='big') + print(burst_payload_crc) - if burst_payload_crc == data_in[1:3]: #IF burst payload crc and input crc are equal - print(data_in[1:3]) - print("CRC EQUAL") - logging.info("TX | SENDING ACK [" + str(data_in[1:3]) +"]") + if burst_payload_crc == data_in[1:3]: #IF burst payload crc and input crc are equal + + print(data_in[1:3]) + print("CRC EQUAL") + logging.info("TX | SENDING ACK [" + str(data_in[1:3]) +"]") #BUILDING ACK FRAME ----------------------------------------------- - ack_frame = b'\7' + bytes(burst_payload_crc) - ack_buffer = bytearray(static.ARQ_PAYLOAD_PER_FRAME) - ack_buffer[:len(ack_frame)] = ack_frame # set buffersize to length of data which will be send - + ack_frame = b'\7' + bytes(burst_payload_crc) + ack_buffer = bytearray(static.ARQ_PAYLOAD_PER_FRAME) + ack_buffer[:len(ack_frame)] = ack_frame # set buffersize to length of data which will be send #TRANSMIT ACK FRAME ----------------------------------------------- + time.sleep(2) + modem.Transmit(ack_buffer) + static.ARQ_RX_BUFFER = [] - modem.Transmit(ack_buffer) - static.ARQ_RX_BUFFER = [] - else: #IF burst payload crc and input crc are NOT equal - print("CRC NOT EQUAL!!!!!") - print(data_in[1:3]) - static.ARQ_RX_BUFFER = [] + else: #IF burst payload crc and input crc are NOT equal + print("CRC NOT EQUAL!!!!!") + print(data_in[1:3]) + static.ARQ_RX_BUFFER = [] def ack_received(): @@ -91,44 +94,84 @@ def transmit(data_out): static.TX_BUFFER = [data_out[i:i+static.ARQ_PAYLOAD_PER_FRAME] for i in range(0, len(data_out), static.ARQ_PAYLOAD_PER_FRAME)] # split incomming bytes to size of 30bytes - arq payload static.TX_BUFFER_SIZE = len(static.TX_BUFFER) + static.ARQ_TX_N_FRAMES = n_frames_per_burst(len(data_out)) # DEFINE NUMBER OF FRAMES PER BURSTS logging.info("TX | TOTAL PAYLOAD BYTES/FRAMES TO SEND: " + str(len(data_out)) + " / " + str(static.TX_BUFFER_SIZE)) - + #print(static.TX_BUFFER[2]) for n_raw_frame in range(0, static.TX_BUFFER_SIZE, static.ARQ_TX_N_FRAMES): # LOOP THROUGH DATA LIST with steps = ARQ_TX_N_FRAMES - print("N_RAW_FRAME: " + str(n_raw_frame)) + print("N_RAW_FRAME: " + str(n_raw_frame)) + + ## check, if we have to adjust burst frames + #if (n_raw_frame % static.TX_BUFFER_SIZE) != 0: + # static.ARQ_TX_N_FRAMES = (n_raw_frame % static.TX_BUFFER_SIZE) + # print(static.ARQ_TX_N_FRAMES) + + # ----------- GENERATE PAYLOAD CRC FOR ARQ_TX_N_FRAMES burst_total_payload = bytearray() - for i in range(static.ARQ_TX_N_FRAMES): #bytearray(b'111111111111111111111111222222222222222222222222') - # we need to make sure, payload data is always as long as static.ARQ_PAYLOAD_PER_FRAME beacuse of CRC! - burst_raw_payload = static.TX_BUFFER[n_raw_frame + i] - burst_payload = bytearray(static.ARQ_PAYLOAD_PER_FRAME) - burst_payload[:len(burst_raw_payload)] = burst_raw_payload # set buffersize to length of data which will be send - burst_total_payload = burst_total_payload + burst_payload - + + + #---------------------------------------------------------------------------------------------------------- + try: # DETECT IF LAST BURST + for i in range(static.ARQ_TX_N_FRAMES): #bytearray(b'111111111111111111111111222222222222222222222222') + + # we need to make sure, payload data is always as long as static.ARQ_PAYLOAD_PER_FRAME beacuse of CRC! + + burst_raw_payload = static.TX_BUFFER[n_raw_frame + i] + burst_payload = bytearray(static.ARQ_PAYLOAD_PER_FRAME) + burst_payload[:len(burst_raw_payload)] = burst_raw_payload # set buffersize to length of data which will be send + burst_total_payload = burst_total_payload + burst_payload + + except IndexError: # IF LAST BURST DETECTED BUILD CRC WITH LESS FRAMES AND SET static.ARQ_TX_N_FRAMES TO VALUE OF REST! + print("LAST BURST!!!") + burst_total_payload = bytearray() # reset burst_total_payload because of possible input remaining of detecting loop one step above + n_last_burst = (static.TX_BUFFER_SIZE % n_raw_frame) + print(n_last_burst) + static.ARQ_TX_N_FRAMES = n_last_burst + + for i in range(n_last_burst): #bytearray(b'111111111111111111111111222222222222222222222222') + + burst_raw_payload = static.TX_BUFFER[n_raw_frame + i] + burst_payload = bytearray(static.ARQ_PAYLOAD_PER_FRAME) + burst_payload[:len(burst_raw_payload)] = burst_raw_payload # set buffersize to length of data which will be send + burst_total_payload = burst_total_payload + burst_payload + + #---------------------------------------------------------------------------------------------------------- + + print(burst_total_payload) + burst_payload_crc = crc_algorithm(burst_total_payload) burst_payload_crc = burst_payload_crc.to_bytes(2, byteorder='big') print(burst_payload_crc) static.ARQ_ACK_WAITING_FOR_ID = burst_payload_crc #set the global variable so we know for which ACK we are waiting for + + + + #---------------------------------------------------------------------------------------------------------- #-------------------- BUILD ARQBURSTS + arqburst = [] for i in range(static.ARQ_TX_N_FRAMES): - - frame_type = 10 + static.ARQ_TX_N_FRAMES - frame_type = bytes([frame_type]) - payload_data = bytes(static.TX_BUFFER[n_raw_frame + i]) - - arqframe = frame_type + burst_payload_crc + payload_data + + frame_type = 10 + static.ARQ_TX_N_FRAMES + frame_type = bytes([frame_type]) - buffer = bytearray(static.FREEDV_PAYLOAD_PER_FRAME) # create TX buffer - buffer[:len(arqframe)] = arqframe # set buffersize to length of data which will be send + payload_data = bytes(static.TX_BUFFER[n_raw_frame + i]) + + arqframe = frame_type + burst_payload_crc + payload_data + + buffer = bytearray(static.FREEDV_PAYLOAD_PER_FRAME) # create TX buffer + buffer[:len(arqframe)] = arqframe # set buffersize to length of data which will be send - arqburst.append(buffer) + arqburst.append(buffer) + + #---------------------------------------------------------------------------------------------------------- #--------------------------------------------- N ATTEMPTS TO SEND BURSTS IF ACK FAILS @@ -137,6 +180,7 @@ def transmit(data_out): static.ACK_RECEIVED = 0 # ----------------------- Loop through ARQ FRAMES BUFFER with N = Numbers of frames which will be send at once + for n in range(static.ARQ_TX_N_FRAMES): logging.info("TX | SENDING BURST " + str(n+1) + " / " + str(static.ARQ_TX_N_FRAMES)) modem.Transmit(arqburst[n]) @@ -171,5 +215,22 @@ def transmit(data_out): #-------------------------BREAK TX BUFFER LOOP IF ALL PACKETS HAVE BEEN SENT if n_raw_frame == static.TX_BUFFER_SIZE: break + + # ------------ TIMER TO WAIT UNTIL NEXT PACKAGE WILL BE SEND TO PREVENT TIME ISSEUS + time.sleep(5) - logging.info("TX | BUFFER EMPTY") \ No newline at end of file + logging.info("TX | BUFFER EMPTY") + + + + +# BURST MACHINE TO DEFINE N BURSTS PER FRAME +def n_frames_per_burst(len_data): + + if len_data <= static.ARQ_PAYLOAD_PER_FRAME: + n_frames_per_burst = 1 + else: + n_frames_per_burst = 3 + + + return n_frames_per_burst \ No newline at end of file