5
D. Random number generation options
These options allow you to actually reproduce the same exact simulation by means of resetting the random number generator
to a known seed.
• LTE_config.seedRandStream: in order to allow repeatability, it is possible to seed MATLAB’s default random
number generator. Set it to either true or false.
• LTE_config.RandStreamSeed: if the above is set to true, it specifies the seed. Seeds must be an integer between
0 and 2
32
[4].
E. Simulation time
• LTE_config.simulation_time_tti: length of the simulation in Transmission Time Intervals (TTIs).
F. Cache options
• LTE_config.cache_network: whether you want to save the generated eNodeBs, Pathloss map and Shadow fading
map to a .mat file. Either true or false. All cache options work in the following way:
– cache=true and file exists: read cache file.
– cache=true and file does not exist: create and then store data in cache file.
– cache=false: do not use cache at all.
• LTE_config.network_cache: the name of the cache file. set it to auto if you want the simulator to assign a name
automatically.
• LTE_config.delete_ff_trace_at_end: since the microscala fading trace takes up large amounts of space, when
doing the final save command, it is preferable to delete it, so as not to have too large result files.
• LTE_config.delete_pathloss_at_end: Further reduces the amount of space needed to store the traces by
deleting the pathloss maps from the results file.
• LTE_config.UE_cache: whether to save the user position to a file. Either true or false.
• LTE_config.UE_cache_file: the name of the cache file. set it to auto if you want the simulator to assign a name
automatically.
G. Network layout and macroscopic pathloss parameters
These parameters specify how the network layout is created. However, if the map is loaded, these parameters will be
overwritten by the loaded map.
• LTE_config.network_source: Available options
– generated: A hexagonal grid of equidistantly-spaced eNodeB sites with three sectors each will be created.
– capesso: eNodeB position, configuration, and pathloss data are read from data exported from and written from
the Capesso
TM
planning tool (see Section XI). When using this source, shadow fading data is not generated, as the
imported pathloss maps should already have it incorporated.
– fixed: Generates N eNodeBs, each with a constant pathloss specified in the LTE_config.pathlosses vector,
containing N values in dB. Useful for comparison with link level results, where a single pathloss value would be
desired for all of the UEs.
1) Generated network parameters:
• LTE_config.network_geometry: Available options
– regular_hexagonal_grid: Regular hexagonal grid with fixed inter-eNodeB distance, as defined in LTE_config.inter_eNodeB_distance
– stochastic: Stochastic eNodeB distribution with spatial density
– hybrid: Hybrid spatial distribution with deterministic- and random parts
– predefined: eNodeB locations as given in LTE_config.eNodeB_positions
The functions are defined in +network_geometry.
• LTE_config.map_resolution: in meters/pixel. Also the resolution used for initial user creation.
• LTE_config.nr_eNodeB_rings: number of eNodeB rings. 0 rings specifies that just a single eNodeB will be created.
• LTE_config.minimum_coupling_loss (optional): describes the minimum loss in signal [dB] between Base Station
(BS) and UE or UE and UE in the worst case and is defined as the minimum distance loss including antenna gains measured
between antenna connectors. Recommended values [5] are 70 dB for urban areas, 80 dB for rural.
• LTE_config.macroscopic_pathloss_model: sets what macroscopic pathloss model is to be used. Depending
on the choice, different choices are available for
LTE_config.macroscopic_pathloss_model_settings.environment. The available macroscopic pathloss
models are:
