0.5.rar_carrier

function [NewEvents] = action(event, log_file) % debug: % TTL is determined at network layer only % one way transmission received, reverse transmission fails, why? % mainly because randomness in the 'shadowing' model: solved...same distance generates same random number % friis model works fine % tworay model is mostly the same as friis because crossover distance = 100 m % freq should be 2.4G instead of 2.4M, white_noise_variance is changed correspondingly % Duplicated packets due to early time out and retransmission: this is ok, just provide a larger timeout % queue waiting problem: net_queue is actually always empty, all NET packets stack at mac_queue % mac_queue is accompanied by mac_status % Question 1: how to decide the priority of broadcast, unicast transmission and receptioin? % to add virtual carrier sense: done % to add RTS-CTS: done % to add ad hoc routing: done % to add application layer actions: % to add figures or animations to show network and traffic change: not critical global adebug bdebug; global Gt Gr freq L ht hr pathLossExp std_db d0 rmodel; global cs_threshold white_noise_variance rv_threshold rv_threshold_delta; global slot_time CW_min CW_max turnaround_time max_retries SIFS DIFS cca_time basic_rate default_power; global max_size_mac_body size_mac_header size_rts size_cts size_ack size_plcp; global n node Event_list; global packet_id retransmit pending_id mac_queue backoff_attmpt backoff_counter backoff_attempt; global nav; global ack_tx_time cts_tx_time rts_tx_time; global default_rate default_ttl; global size_rreq size_rrep; global rreq_timeout net_queue net_pending net_max_retries; global rrep_table; % id, route, metric global bcast_table; global mac_status; global adebug bdebug cdebug ddebug; global rreq_out rreq_in rreq_forward; global rreq_out_crosslayer rreq_in_crosslayer rreq_forward_crosslayer; global rrep_out rrep_in rrep_forward; global rrep_out_crosslayer rrep_in_crosslayer rrep_forward_crosslayer rrep_destination_crosslayer; NewEvents = []; switch event.type case 'send_phy' t = event.instant; i = event.node; j = event.pkt.rv; if adebug, disp(['send_phy at time ' num2str(t) ' node ' num2str(i) ' will send a packet to node ' num2str(j)]); end txtime = tx_time(event.pkt); if node(i, 4) == 0 & (nav(i).start > (t+txtime) | nav(i).end < t) % idle and no nav node(i, 3) = event.pkt.power; node(i, 4) = 1; % switch to transmit mode, assume turnaround time is zero % set up the receiver if j == 0 % broadcast from node i for k=1:n % due to broadcast nature in wireless channel, every idle node may capture/sense this transmission if node(k, 4)~=0 | k==i, continue; end if overlap(t, t+txtime, nav(k).start, nav(k).end), continue; end node(k, 4) = 2; % receiver switches to receiving mode newevent = event; newevent.instant = t + txtime; newevent.type = 'recv_phy'; newevent.node = k; NewEvents = [NewEvents; newevent]; clear newevent; end % when there is no node to receive this broadcast, still send it. % because I do not know if any node will respond, but actually node node will respond. % if length(NewEvents) <= 0 % if ddebug, disp(['send_phy: node ' num2str(i) ' broadcasts to no nodes']); end % newevent = event; % newevent.instant = t; % newevent.type = 'send_phy_finish'; % newevent.node = i; % NewEvents = [NewEvents; newevent]; clear newevent; % return; % end else % unicast from i to j if node(j, 4) ~= 0 | overlap(t, t+txtime, nav(j).start, nav(j).end) if ddebug, disp(['send_phy: receiving node ' num2str(j) ' is not ready to receive from node ' num2str(i)]); end % At physical layer, I cannot synchronize with the receiver, so I know I do not need to actually transmit? % We sill transmit this packet, but no actual reception. % newevent = event; % newevent.instant = t; % newevent.type = 'send_phy_finish'; % newevent.node = i; % NewEvents = [NewEvents; newevent]; clear newevent; % return; else node(j, 4) = 2; % receiver is switched to receiving mode newevent = event; newevent.instant = t + txtime; newevent.type = 'recv_phy'; newevent.node = j; NewEvents = [NewEvents; newevent]; clear newevent; end for k=1:n % due to broadcast nature in wireless channel, every idle node may capture/sense this transmission if node(k, 4)~=0 | k==i | k==j, continue; end if overlap(t, t+txtime, nav(k).start, nav(k).end), continue; end node(k, 4) = 2; % receiver switches to receiving mode newevent = event; newevent.instant = t + txtime; newevent.type = 'recv_phy'; newevent.node = k; NewEvents = [NewEvents; newevent]; clear newevent; end end % setup the transmitter newevent = event; newevent.instant = t + txtime + eps; newevent.type = 'send_phy_finish'; newevent.node = i; NewEvents = [NewEvents; newevent]; clear newevent; if strcmp(event.pkt.type, 'rts') % set timeout timer for RTS newevent = event; newevent.instant = t + (txtime + SIFS + cts_tx_time) * 2; % question: how to choose this timeout limit? newevent.type = 'timeout_rts'; newevent.node = i; NewEvents = [NewEvents; newevent]; clear newevent; if retransmit(i) <= 0 & pending_id(i) > 0 error(['send_phy: node ' num2str(i) ' there is already a pending packet, cannot send a new RTS packet']); end pending_id(i) = event.pkt.id; end if strcmp(event.pkt.type, 'data') & j ~= 0 % set timeout timer for DATA newevent = event; newevent.instant = t + (txtime + SIFS + ack_tx_time) * 2; % double check newevent.type = 'timeout_data'; newevent.node = i; NewEvents = [NewEvents; newevent]; clear newevent; if retransmit(i) <= 0 & pending_id(i) > 0 error(['send_phy: node ' num2str(i) ' there is already a pending packet, cannot send a new DATA packet']); end pending_id(i) = event.pkt.id; end else % radio hardware is not idle or nav block if adebug, disp(['send_phy at time ' num2str(t) ' node ' num2str(i) ' is not ready to send a packet to node ' num2str(j)]); end if adebug, disp(['--- node(i, 4)=' num2str(node(i, 4)) 'nav.start=' num2str(nav(i).start) 'nav.end=' num2str(nav(i).end)]); end % Since the node status is already checked at MAC layer, it must be due to NAV virtual carrier sense % I am a hiddent node: physical carrier sense is okay, but blocked