FS-1045A: Appendix B

• C: number of channels in scan sequence
• H: handshake. Completed sequence of call, response and acknowledgment
• n: integer
• NA: number of addresses
• NA_m: number of addresses with "m" words
• NAW: number of original individual address words
• NS: number of slots in response period, total (includes slot Ø)
• P_l: probability of linking (three-way handshake)
• s: seconds
• SN: slot number identification
• T: time
• T_a: individual station (or net) whole address time
• T_a1: individual station (or net) address first word time
• T_amax: maximum individual station (or net) whole address time limit
• T_ar: acknowledgment received event time
• T_c: call time, combination of whole address(es), which is usually repeated as a leading call T_lc
• T_c1: combined different first words of group station addresses
• T_cc: calling cycle time
• T_cmax: maximum call time limit (of the call)
• T_d(5): &
• T_d(2): basic dwell time on each channel during scan. Number is channels per second scanning rate.
• Tdbm: data block message time
• T_dek: decode time
• T_drrw: detect rotating redundant word time
• T_drw: detect redundant word time
• T_ds: detect signaling (tones and timing) time
• T_enk: encode time
• T_hs: handshake time, start to finish total (without tuning)
• T_lc: leading call time
• _ld: late detect word additional time
• T_lww: last word wait delay
• T_m: orderwire message section time
• T_mmax: maximum orderwire message section time limit
• T_p: propagation time
• T_ps: periodic sounding interval
• T_rc: redundant call time
• T_rd: receiver internal signal delay time
• T_rr: response received event time
• T_rs: redundant sound time
• T_rw: redundant word time (392 ms)
• T_rwp: redundant word phase delay (0 to T_rw)
• T_s: scan period
• T_smin: minimum scan period
• T_smax: maximum scan time
• T_sc: scan calling time, same as T_ss
• T_src: scanning redundant call time
• T_srs: scanning redundant sound time
• T_ss: scan sounding time, same as T_sc
• T_sw: slot width time
• T_swf: fixed slot width time
• T_swt: slot wait time delay after end of call, until slotted response starts
• T_t: tune-up time delay of antenna tuner or coupler
• T_ta: turnaround time, receipt of end of signal to start of reply
• T_tc: transmitter command (to transmit) time
• T_td: transmitter internal signal delay time
• T_tk: transmitter acknowledgment (that it is transmitting) time
• T_tone: tone (8 ms)
• T_w: word time (130.66... ms)
• T_wa: wait for activity time
• T_wan: wait for net acknowledgment time (for called stations).
• T_wanmax: maximum limit group call wait for reply time (for late arrival called stations)
• T_wce: wait for calling cycle end (message or terminator sections)
• T_wr: wait for reply time
• T_wrn: wait for net/group reply time (for calling stations)
• T_wrt: wait for reply and tune (scanning) time
• T_wt: wait (listen first) time before tune or transmit
• T_x: termination section time
• _xmax: maximum termination section time limit
• WRT: wait for reply timer (load with T_wr)
• WRTT: wait for reply and tune timer (load with T_wrn or T_wrt)

Basic system timing

• Tone (symbol) rate = 125 symbols per second
• Tone (symbol) period: T_tone = 8 ms per symbol
• On-air bit rate = 375 bits per second
• On-air individual word period (never sent alone): T_w = 16.33... symbols × T_tone = 130.66... ms
• On-air (triple) redundant word period: T_rw = 3T_w = 49 tone = 392 ms
• On-air individual (or net) address time, m = 1 to 5 words: T_a = m × T_rw = 392 ms to 1,960 ms
• Propagation time, range divided by speed of wave, for MF/HF signals, local to global: T_p = 0 to 70 ms

System timing limits

• Maximum individual station (or net) address time limit, based on 15-character (or 5-word) maximum: T_a max = 5 T_rw = 1,960 ms
• Individual (or net) address first word, used in scan call T_sc: T_a1 = T_rw = 392 ms
• Maximum group combined addresses different first words time limit, maximum 5 first words, in scan call T_sc: T_c1 = T_a2 (different) T_c1 max = 5 T_a1 = 5 T_rw = 1,960 ms
• Maximum call time limit, based on 12-word maximum, whole addresses in T_lc: T_c max = 12 T_rw = 4,704 ms
• Maximum scan cycle period limit, based on 2 channels per second and 100 channels: T_s max = 50 s
• Maximum message (orderwire) section time limit, unless adjusted by COMMAND: T_m max basic = 11.76s T_m max AMD = 23.128s T_m max DTM = 353 T_rw + 29 T_rw = 382 T_rw (149.744s) T_m max DBM = 3560 T_rw + 29 T_rw = 3589 T_rw (1406.888s)
• Maximum termination section time limit, same as T_a max: T_x max = T_a max = 1,960 ms

Individual calling

• Initial and minimum dwell time on each channel by receiving station during normal receive scanning, inverse of scanning rate, not including extended pause to read words: T_d(5) min = 200 ms at 5-chps basic scan rate or T_d(2) min = 500 ms at 2-chps minimum scan rate T_d(10) min = 100 ms at 10 chps (DO)
• Scan period for receiving station to scan all scanned channels during normal receive scanning, where "C" is the number of scanned channels, not including extended pause to read words: T_s min = C × T_d min + For examples: T_s min = 0 for single channel, nonscan case, or = 2 seconds for typical C = 10 at 5 chps, or = 5 seconds for C = 10 at 2-chps minimum rate = 1 second for C = 10 at 10 chps (DO)
• For scan call T_sc computations, use T_s based on probable maximum pause on each channel (T_d, to read words) of T_drw = 2 T_rw (T_d may be adjusted by net managers for best system performance): T_s = C × T_d = C × T_drw + For example: T_s = 7,840 ms for C = 10 channels and T_d = T_drw
• Call time, the called address (or combination of called whole addresses, if a group call), which may be repeated in the leading call T_lc; maximum limit 12 address words: T_c = T_a (called) for single station (or net) calls, or = T_a (first) + T_a (second) + . . . T_a (last) if group call
• First word call time, the called address first word (or combination of addresses first words, if a group call), which is repeated in the scanning call T_sc; maximum limit five different first words: T_c1 = T_a1 (called) for single station (or net) calls, or = T_a1 (first) + T_a1 (second and different) +...T_a1 (last different group call)
• Leading call time, composed of two complete repetitions of T_c, which contains the whole address(es): T_lc = 2T_c = 2 T_a (called) for single station (or net) calls, or = 2 (T_a (first) + T_a (second) +...T_a (last)), if group call
• Scanning call time, consisting of repetitions of only the first word(s) T_a1 of the called address (or combination of addresses, if a group call), for calling station to "capture" scanning receivers during normal scanning calling. Therefore, T_sc is a multiple T_c1 (group of T_a1's if a group call) of words, which is the receiver's scan period T_s where n is any integer such that T_sc T_s: T_sc = n × T_c1 T_s = C × T_d + For examples: T_sc = 0 for single channel individual call case, or 20 T_rw = 7840 ms if C = 10 and T_d = T_drw
• Calling cycle time for calling station to both "capture" scanning receivers and ensure reading the called station address(es), consisting of scan period T_sc plus leading call time (T_sc) plus leading call time (T_1c), respectively: T_cc = T_sc + T_1c T_s + T_lc + For examples: T_cc = 2 T_a (called) = 784 ms for single channel one-word address individual (or net) call case (T_s = 0), or = T_sc + T_lc = (20 + 2) T_rw = 8624 ms if C = 10 and T_d = T_drw
• Single channel redundant call time, consisting of individual (or net) leading call T_lc (with TO) plus terminator T_a (with THIS IS or THIS WAS), not including any message section time: T_rc = T_lc + T_x = 2 T_c + T_x = 2 T_a (called) + T_a (caller) = 3 T_rw min = 1176-ms minimum, for individual station (or net) call using one-word addresses. = 15 T_rw min = 5880 ms max for five-word addresses
• Scanning redundant call time, consisting of scanning call time T_sc, and redundant call time T_rc, respectively: T_src = T_sc + T_rc + For example, using one-word addresses: T_src = (20 + 3) T_rw = 9016 ms if C = 10 and T_d = T_drw
• Last word wait additional fixed delay at replying or receiving station, after (possibly early) detected end of received call and before start of reply, to avoid on-air overlap, loss of additional termination (caller address) words, and to allow margin for transmitter turnaround for reception: T_lww = T_rw = 392 ms
• Late word detection additional fixed delay at calling station, to increase wait for reply time in case of possibly late detection at called station: T_ld = T_w = 130.66... ms
• Redundant word phase delay. To synchronize a transmission to preceding transmissions, within the same session, and used on all but first transmission of a handshake or exchange until terminated period: T_rwp = 0 to 392 ms T_rw
• Turnaround time at replying station, measured at rf port(s); from end of received signal to start of transmitted reply, not including delays such as T_lww or T_ld and including receiver and transmitter internal signal delays, T_rd and T_td; decode and encode times, T_dek and T_enk; and transmitter command and acknowledgment delays, T_tc and T_tk: T_ta = T_rd + T_dek + T_enk + T_tc + T_tk + T_td + For examples: (approximations) T_ta = 0 for new, fast equipment, or = 2 T_w = 261.33...ms estimated allowance for old slower equipment
• Wait for calling cycle end time at receiving station, is delineated by receipt of start of message, terminator, or quick-ID section: T_wce = 2 × T_s (of own station), as default value
• Wait for reply time at calling station, from end of transmitter signal to start of received reply detection periods (T_ds, T_drw, and T_drrw, below); including propagation, T_p; last word wait, T_lww; late word detection, T_ld; turnaround, T_ta; redundant word phase delay (if not first transmission in handshake or exchange), T_rwp;, and receiver and transmitter internal signal delays, T_rd and T_td; in a single channel case without tune times, or multi-channel scanning case after first tune and transmission: T_wr = T_td + T_p + T_lww + T_ta + T_rwp (if not first) + T_ld + T_p + T_rd + For example: (approximations) T_wr = 5 T_w = 653.33... ms for fast equipment, or = 7 T_w = 914.66... ms for slower equipment, maximum = 8 T_w = 1045.33...ms for fast equipment if not first = 10 T_w = 1306.66...ms for slower equipment if not first
• Tune time delay, after issuance of tune-up command and before ready to transmit the reply signal: T_t = maximum tune-up delay for slowest tuner in system (or net/group being called) + For examples, typical allowance ranges are: T_t T_w = 130.66... ms for fast (solid state) tuners or 8 T_w = 1,045.33... ms for fast relay tuners, or 20 seconds for old electromechanical (servo drive) tuners, or as required by available equipment NOTE: If tune time(s) of called station(s) is(are) unknown, the first-try default value shall be 8 T_w and the second-try default value shall be at least 20 seconds.
• Wait for response and tune time, same as wait for reply T_wr, plus tune time T_t in scanning cases, and relevant only to first transmission on a channel (which requires tuning time): T_wrt = T_wr + T_t + For examples, typical allowance ranges: T_wrt = 6 T_w = 784 ms for fast tuners, or 15 T_w = 1,960 ms for slower tuners, or adjusted as required by available equipment NOTE: If tune time(s) of called station(s) is(are) unknown, the first-try default value shall be 15 T_w and the second-try default value shall be at least 20 seconds.
• Detect signaling tones and timing (of call or reply) detection period; after arrival on channel during normal receive scanning, or after end of wait for reply time T_wr or T_wrt during normal calling, and before automatic return to normal receive scanning; used to identify channel vacancy or occupancy with standard ALE signaling. T_ds < T_d(5) = 200 ms NOTE: The test for this ability is based on the station stopping scan (at 5 chps) when called.
• Detect redundant words detection period, starting same as T_ds, and used to continue beyond T_ds if tones and timing are detected, before automatic return to normal receive scanning; used for acceptance of basic single- word (and address first word) addressing and to read calls: T_drw = T_rw + spare T_rw = 6 T_w = 784...ms
• Detect rotating redundant words detection period, starting same time as T_ds, and used to continue beyond T_drw if redundant words are detected, before automatic return to normal receive scanning; used for acceptance of extended (multiword) addressing and/or group calls: T_drrw = 2 T_rw + spare T_rw = 9 T_w = 1,176 ms

Sounding

• Single channel redundant sound time, like leading call T_lc, but with only the THIS IS or THIS WAS terminator, using twice the whole address: T_rs = 2 T_a (caller) For example: T_rs = 2 T_rw = 784 ms minimum, individual single-word address sound on a single channel
• Scanning sound time. Like T_sc, but using whole address only (not just first word of address): T_ss = n × T_a (caller) T_s
• Scanning redundant sound time, like calling cycle time, T_cc, consisting of redundant sound time T_rs, with addition of scanning sounding time T_ss (which is identical to T_sc): T_srs = T_ss + T_rs = (2 + n)T_a (caller) T_s + T_rs For example: T_srs = (20 + 2) T_rw = 8624 ms if C = 10 and T_d = T_drw

Star calling

• Minimum uniform slot width for automatic slotted responses in normal single-word address star net and group calling protocols (but may be modified by COMMAND): T_sw (min) = 14 T_w = 1,829.33... ms for standard replies, or = 17 T_w = 2221.33...ms for LQA replies, or = 9 T_w = 1,176 ms for only fixed "tight slot" replies, or = n × T_w by COMMAND NOTE: Replies above are for first transmissions; if not, T_sw min = 17, 20, and 12 T_w respectively (due to redundant word-phase delay).
• Slot wait time before start of slotted response and after detection of end of calling signal, where "SN" is the assigned (or derived) slot number, for group or preset net calling: T_swt(SN) = T_sw × SN for uniform slot widths (by COMMAND or net manager), or if nonuniform (customized) slot width: T_swt(SN) = SN[5 T_w + 2T_a (caller) + (optional LQA) T_rw + (optional message) T_m] + T_a (caller) + [(sum of all previous called addresses) m = SN-1 T_a(m) (called)] as the general case. m = 1 For example: T_swt(5) = 14 T_w × 5 = 70 T_w = 9,146.66... ms delay for start of normal 5th slot response, first time, no LQA, single-word address.
• Wait for net reply buffer time at calling station, after end of star net or group call, until responses should be received and an acknowledgment can be started, where NS is the total number of slots including slot 0: T_wrn(calling) = (T_sw × NS) for uniform slots or generally, = T_swt(NS)
• Wait for net acknowledge buffer time at called stations, to receive acknowledgment after end of star net or group call: T_wan(called) = (T_sw × NS) + T_drw = T_wrn(calling) + 2 T_rw
• Turnaround plus tune time totals for slotted responses have the following limits (not including T_lww): T_ta + T_t 1500 ms for standard slots, except 2100 ms for slot 1 only, or 360 ms for slot 0 emergency or interrupt
• Maximum star group wait for acknowledgment time at called stations: T_wan max = 107 T_w + 27 T_a(caller) + 13 T_rw (optional LQA) + 13 T_m (optional message)
• Default maximum star group wait for acknowledgment time for late arrival, called stations, not knowing the size of the group. There are two default maximum waiting values, before automatically returning to normal receive scanning, if no message and caller uses single-word address: T_wan max = 188 T_w = 24,565.33...ms if standard, or = 227 T_w = 29,661.33...ms if LQA requested

Programmable timing parameters

Unless otherwise programmed by the network manager, the following typical timing values are recommended:

• Dwell time per channel, basic receive scanning: T_d(5) = 200 ms for 5-chps basic scan rate
• Dwell time per channel, minimum receive scanning: T_d(2) = 500 ms for 2-chps minimum scan rate
• Dwell time for calculations of T_s (and T_sc), based on probable maximum typical pause (may be adjusted by net manager for best system performance): T_d = T_drw = 2 T_rw = 784 ms
• Wait (listen first) time before tune or transmit: T_wt = 2 seconds for voice or general purpose channels, or = T_drw = 784 ms for ALE and data only channels
• Tune time allowance for wait for response time is normally set for slowest known tuner in associated network; except if unknown parameter (such as in blind internet calls to "strangers"): T_t = 8T_w = 1045.33... ms for first call, and = 20 seconds for next try
• Automatic periodic sounding intervals (when channels are clear): T_ps = 30 minutes when enabled (disableable).
• Wait for activity time after linking or use, before automatic return to normal receive scanning: T_wa = 30 seconds when enabled (disableable).

• Required audio bandwidth: 300 - 3050 Hz
• ALE occupied bandwidth: 500 - 2750 Hz
• Quantity of tones: 8 (one per symbol period)
• Tone frequencies: 750; 1000; 1250; 1500; 1750; 2000; 2250; 2500 Hz
• Tone values: 000 001 011 010 110 111 101 100
• Symbol changes: Tone transitions are phase continuous
• Symbol structure: 3 bits of binary coded data
• Symbol rate; period: 125 symbols per second (sps); 8 ms
• Coded data rate: 375 bits per second (bps) transmitted
• Forward error correction (FEC): Golay (24, 12, 3) half-rate coding (4 modes of correct/detect; 3/4, 2/5, 1/6, or 0/7)
• Auxiliary coding (DTM, AMD, basic ALE): Redundant × 3, with 2-of-3 majority vote (with 49 transmitted bits)
• Auxiliary coding (DBM): Deep interleaving = 49 to 21805 = (n × 49)
• Uncoded data rate (DTM, AMD, basic ALE): 61.22 bps
• Uncoded data rate (DBM): 187.5 bps
• Uncoded data bits per basic ALE word (DTM, AMD): 24 (21 (3 characters) plus 3 preamble), per word
• Uncoded data bits per message (DTM): From 0 to 7371 bits per block
• Uncoded data bits per message (DBM): From 0 to 261644 bits per block, plus 16 bits CRC
• Throughput maximum data rate (DTM, AMD, basic ALE): 53.57 bps data bits
• Throughput maximum data rate (DBM): 187.5 bps data bits
• Characters per word (AMD or basic ALE): 0 to 3, expanded 64-ASCII subset or full ASCII
• Characters per message (DTM): 0 to 1053 full ASCII characters per block
• Characters per message (DBM): 0 to 37377 full ASCII characters per block
• Character rate (DTM, AMD, basic ALE): 7.653 cps
• Character rate (DBM): 26.79 cps
• Equivalent thruput, maximum word rate (DTM, AMD): 76.53 words per minute (wpm) (5 characters plus space per word)
• Equivalent thruput, maximum word rate (DBM): 267.9 wpm (5 characters plus space word)
• Unit period (DTM, AMD, or ALE word): 130.66... ms per word (T_w) or 392 ms per redundant word (T_rw)
• Message period (DTM): 0 to 2.29 minutes per block
• Message period (DBM): 0 to 23.26 minutes per block
• Minimum sound time: 784 ms (2 T_rw)
• Minimum call time: 1176 ms (3 T_rw)
• Minimum handshake time: 3528 ms (9 T_rw) three-way linking
• Preambles (word types): 8 (3 bits)
• Character sets: ASCII (basic 38, expanded 64, full 128) or random bits
• Link quality analysis (LQA): ALE (BER, SINAD, and MP)

NOTE: Automatic message display (AMD) characteristics are the same as data text message (DTM).