Setting manual ROI

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    I need to set the region of interest manually so I can place UEs on the central eNodeB alone, and that calls for me to define an hexagonal ROI.
    From time, I think this is the regular pattern for setting ROI:
    LTE_config.roi_x = [-1000 1000];
    LTE_config.roi_y = [-1000 1000];

    Am I correct?

    I am certain this can only define ROI to be a rectangular shape, how may I modify the ROI code to place UEs only on the central eNodeB.

    I am trying to simulate a non interference scenario by
    1. Placing UEs only on the desired eNodeB and
    2. Turning of unattached eNodeBs

    Is this an elegant approach?
    Are there better ways to achieve this same objective?



    Hi John,

    If you don’t want to have any interference in your network, why don’t you simply simulate 0 rings of BSs (by setting LTE_config.nr_eNodeB_rings = 0)? This will create just one eNodeB in the center of your ROI. To also avoid interference among the 3 BS sectors, you might want to switch to an omnidirectional antenna pattern (LTE_config.antenna.antenna_gain_pattern = ‘omnidirectional’), which will then only create one eNodeB object.

    Note however, that without interference you are often in saturation (regarding SINR) so your results might not be very meaningful.

    This does not answer your question regarding the ROI, but changing that might be unnecessary then when only generating a single eNodeB. Please let me know if you still want to change ROI size and/or UE placement and assignment.

    Best regards,


    Thank you very much for the response;

    We initially considered the idea of setting LTE_config.nr_eNodeB_rings=0, but due to;
    (1) The simulation requirements
    (2) necessary GUI modifications -we placed concentric hexagonal cells around the middle eNodeB (LTE_config.nr_eNodeB_rings=0 makes eNodeB 5 to cover the entire plot region which is not an hexagon),

    we couldn’t. Although we would attempt it if there is a way where simulating only the central eNodeB would produce a regular hexagonal coverage region. We would need alternatives otherwise.

    Please take a look at:
    IWSLS2’16] Paper (Using System-Level Simulation to Evaluate Downlink Throughput Performance in LTE-A Networks with Clustered User Deployments) for a better understanding of the scenario.

    Is there any direct or indirect way to turn OFF a specific eNodeB?

    +Thanks for the advice, we were using Omnidirectional gain pattern



    Dear John,

    If you really want to work with hexagonal-shape cells, then I suggest the following:

    1. Set the number of LTE_config.nr_eNodeB_rings=1;
    2. Set the parameter LTE_config.compute_only_center_users = true; -> with this you will get the results only for the UEs assigned to the center eNodeB
    3. To avoid the calculation of interference from interfering eNodeBs in your results, you could set the parameter there_are_interferers = false; Set this parameter at +network_elements/UEs.m inside the function “function link_quality_model_v1(obj,config)”, after the execution of obj.get_signal_macroscale_losses; basically you have to overwrite the parameter there_are_interferer and set it to false.

    This is the easiest approach to achieve what you asked for. If you still want to modify ROI, I can give you more hints on that.

    Best regards,

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