Scenario card: smoke

Small street grid that runs in seconds
Available since version 0.2.0. Use it as scenario: smoke in a configuration file or hl.builtin_scenario("smoke") in Python.

Purpose

A quick, complete run of every part of the simulator: a 2 x 2-block street grid with buildings, the spatially consistent LOS state, place-tied shadowing, 20 vehicular users and 30 s of simulated time. It is the scenario of the golden event-log fingerprints, of the rule contract checks (handoverlab.testing.check_rule) and of first experiments. It is too small and too short for statistical conclusions.

Layout

Layout of smoke

Two by two blocks of the TR 37.885 urban grid (smaller than the minimum 3 x 3 area of TR 37.885 Table A-1), sites every 150 m along the streets.

Parameters

Values in bold differ from the HandoverLab defaults.

Key Value Source
layout.kind street_grid TR 37.885 Annex A (urban grid)
layout.blocks [2, 2] assumption (smaller than TR 37.885 Table A-1, for speed)
layout.pitch_m [433, 250] TR 37.885 Annex A (433 m x 250 m)
layout.street_width_m 20 TR 37.885 Annex A (20 m)
layout.site_spacing_m 150 assumption
layout.site_offset_m 9 assumption (sites on the pavement)
layout.sites none regular placement along the streets
radio.carrier_ghz 10 assumption (upper mid-band, 7-24 GHz)
radio.bandwidth_mhz 200 assumption
radio.tx_power_dbm 35 assumption (small cell; TR 37.885 Table 6.1.1-2 has 43 dBm for its macro sites)
radio.bs_gain_db 20 assumption (beam gain, no beam management)
radio.ue_gain_db 0 assumption
radio.noise_figure_db 7 assumption (typical UE noise figure)
radio.isolation 0.3 assumption (mean-to-peak gain of an interfering data beam)
radio.bs_height_m 10 TR 38.901 Table 7.4.1-1 (UMi: 10 m)
radio.ue_height_m 1.6 TR 37.885 clause 6.1.2 (urban option A: 100 % vehicle type 2, antenna height 1.6 m; since 2.1.0, until 2.0.0 1.5 m)
radio.pathloss umi_street_canyon TR 38.901 Table 7.4.1-1
radio.shadow_los_db 4 TR 38.901 Table 7.4.1-1 (UMi and UMa LOS: 4 dB)
radio.shadow_nlos_db 7.82 TR 38.901 Table 7.4.1-1 (UMi NLOS: 7.82 dB)
radio.shadow_decorr_m 10 TR 38.901 Table 7.5-6 Part-1 (UMi: 10 m LOS, 13 m NLOS; the LOS value is used for both, see the limitations)
radio.shadow_site_corr none unset: uncorrelated between sites, TR 38.901 clause 7.5 step 4 (radio.channel_detail simple: 0.5)
radio.place_share 1 assumption (blockage tied to place)
radio.clutter_los true TR 38.901 clause 7.6.3.3 (spatially consistent LOS state), applied on top of the building geometry
radio.los_corr_m 50 TR 38.901 Table 7.6.3.1-2 (LOS/NLOS state, UMi and UMa: 50 m)
radio.time_var_db 1.5 assumption (moving blockers)
radio.time_var_tau_s 1 assumption
radio.l1_error_db 1 assumption (error of one L1 RSRP sample)
radio.penetration_db 0 off by default; TR 38.901 clause 7.4.3.2: 9 dB in a standard car
radio.penetration_sd_db 0 off by default; TR 38.901 clause 7.4.3.2: 5 dB in a standard car
radio.energy_p0_w 56 EARTH model, micro base station (Auer et al. 2011, Table 2): 56 W
radio.energy_slope 2.6 EARTH model, micro base station (Auer et al. 2011, Table 2): 2.6
radio.map_res_m 2 numerical setting (coarser map for speed)
protocol.step_s 0.01 numerical setting
protocol.l1_period_s 0.04 assumption (L1 sample period)
protocol.l3_k 4 TS 38.331 clause 5.5.3.2
protocol.label_period_s 0.2 numerical setting
protocol.report_interval_s 0.12 TS 38.331 reportInterval (ms120)
protocol.qout_db -8 TR 36.839 (Qout -8 dB)
protocol.qin_db -6 TR 36.839 (Qin -6 dB)
protocol.qout_window_s 0.2 TS 38.133 (evaluation period, 200 ms)
protocol.qin_window_s 0.1 TS 38.133 (evaluation period, 100 ms)
protocol.n310 1 TR 36.839
protocol.n311 1 TR 36.839
protocol.t310_s 1 TR 36.839 (1 s)
protocol.prep_s 0.05 TR 36.839 (50 ms)
protocol.exec_s 0.04 TR 36.839 (40 ms)
protocol.reest_s 1 assumption (1 s outage); TS 38.133 6.2.1.2.1 bounds the delay by 50 ms + cell identification (FR1: 200 ms known, 800 ms unknown cell, Table 6.2.1.2.1-1) + system information + PRACH; TR 36.842 Table E.1-2 uses 250 ms
protocol.cho_recovery_s 0.4 TS 38.300 clauses 9.2.3.1 and 9.2.7 (recovery into a CHO candidate; assumption 0.4 s)
protocol.pingpong_s 1 TR 36.839 (minimum time of stay, 1 s)
protocol.cfg_loss_as_failure false check mode only
protocol.lm_load none off by default: link monitoring sees the load of the data channel (calibration option)
protocol.lm_load_per_ue 0 off by default (calibration option)
protocol.exec_can_fail true TR 36.839: the execution fails when the target is below Qout
protocol.rlm_holdoff_s 0.2 0.2 s since 2.0.0: an interpretation of TS 38.133 8.1.2.2 (evaluation over the last T_Evaluate_out, 200 ms in FR1) on a newly joined cell
traffic.services 5 entries TS 23.501 Table 5.7.4-1 (5QI); thresholds are assumptions
traffic.se_max 7.4 assumption (spectral-efficiency cap)
traffic.hotspot_share 0.25 assumption
traffic.hotspot_load [0.55, 0.85] assumption
traffic.normal_load [0.05, 0.25] assumption
traffic.load_tau_s 0.2 assumption
traffic.rate_scale 1 assumption
traffic.label_load 1 assumption (all cells transmit for the label)
traffic.model fixed fixed: constant service rates (the model of 1.0)
traffic.period_s 0.02 periodic model: 20 ms, as VoIP
traffic.packet_bytes 100 periodic model: assumption
traffic.ftp_file_bytes 500000 FTP model 3 (TR 36.872 Annex A.1) with 0.5 Mbyte files (TR 38.802 Table A.2.1-1; TR 38.821 Table 6.1.1.1-7)
traffic.ftp_rate_hz 0.1 ftp3 model: assumption (file arrival rate per user)
mobility.users 20 assumption
mobility.profile v60 TR 37.885 clause 6.1.2 (urban option A: 60 km/h in all lanes) and Table A-1 (2 lanes of 3.5 m per direction): profile v60 (since 2.0.0)
mobility.groups none profile
run.duration_s 30 numerical setting (short run)
run.warmup_s 5 numerical setting

Known limitations

  • Small cells on UMi along the streets, as in urban-grid-10ghz (TR 37.885 itself has 500 m macro sites with UMa in the urban grid); the path loss is evaluated at no less than 10 m from a site.
  • Below the minimum area of TR 37.885 Table A-1; users near the edge see fewer neighbours.
  • About 10 UE-minutes per seed: rates have a large sampling error; use it for checks, not for results.
  • The coarser 2 m radio map smooths the LOS edges a little compared with the 1 m default.
  • The LOS state of a link is LOS only if the buildings leave it clear and the spatially consistent LOS variable of TR 38.901 clause 7.6.3.3 is below the LOS probability of Table 7.4.2-1; the share of LOS links is therefore lower than Table 7.4.2-1 gives (which handoverlab verify compares only for the links clear of buildings).
  • One shadowing decorrelation distance, the UMi LOS value of 10 m, also for the NLOS links (TR 38.901 Table 7.5-6 Part-1: UMi LOS 10 m, NLOS 13 m); LOS and NLOS links share one unit shadowing realisation scaled by the LOS or NLOS standard deviation, so the shadowing keeps its sign when a link changes state (TR 38.901 gives separate LOS and NLOS parameters, Table 7.5-6).
  • A vehicle keeps a lane offset drawn at the start, on either side of the street centre line, through turns: it may drive in a lane of the opposite direction (TR 37.885 Table A-1 has 2 lanes in each direction).
  • The number of vehicles is set for run time: TR 37.885 clause 6.1.2 places vehicles with a gap of max(2 m, exponential with mean speed x 2 s), which gives hundreds of vehicles in the grid; the interference load of HandoverLab does not depend on the number of users.

Reference results

  • Golden event-log fingerprints of the built-in rules (handoverlab verify, check group fingerprints).
  • Invariant checks in debug mode and the equivalence 'CHO with immediate execution = A3' (handoverlab verify).