# 8.7.4 System loading

The following procedures can be used for system loading during simulation and preparation of simulation outputs.

**System loading**

To determine the number of active mobile stations *Act\_MS* in the network:

1. Set up:
    
    
    1. Average traffic load in terms of a predefined number of users per cluster: *N\_UL*
    2. standard deviation of log-normal shadowing σ*<sub data-renderer-mark="true">shadowing</sub>*
    3. voice activity factor *Act\_Factor (fixed to 100%)*
    4. target maximum noise rise over the thermal noise in the network η\_*target*
    5. target C/I (*E<sub data-renderer-mark="true">b</sub>/N<sub data-renderer-mark="true">0</sub>*\_*target*) to fulfill service requirement depending on configuration and mobility (provided by link level simulations)
    6. maximum transmit power of mobile station *max\_MS\_Pw\_Tx*
    7. power control range *– MS\_PC\_Rang*:
    8. In the case that the <span data-highlighted="true" data-vc="highlighted-text"><span class="_kqswh2mm"><span class="_5pioz8co _189e1dm9 _1il9buyh _19lc184f _d0altlke" data-testid="definition-highlighter">CDMA</span></span></span> uplink is the victim link, add the received power from the interfering system to the thermal noise power
2. For each event:
    
    
    1. put down uniformly mobile stations at pseudo-random locations across the network and distribute speed among them
    2. Add a new mobile station in the set of active users in the network

<div class="ak-renderer-extension   " data-layout="default" data-node-type="extension" data-testid="extension--wrapper" id="bkmrk-compute-average-path"><div class="ak-renderer-extension-inner-wrapper ak-renderer-extension-overflow-container css-v54qrt"><div class="_1t4wglyw _1syfglyw _1pnoidpf _1gocidpf"><div class="ak-renderer-wrapper is-max css-pw7jst"><div>  
</div><div class="css-9igiaj" role="none"><div class="ak-renderer-document">- - - compute average path-loss from the mobile station to the base station of each cell
        - generate a log-normal pseudo-random value to add to each of the path losses to model shadow fading
        - perform a pseudo-random weighted coin-toss to determine voice activity, where 1 occurs with probability *Act\_Factor*
        - compute required received power at the base station to meet *E<sub data-renderer-mark="true">b</sub>/N<sub data-renderer-mark="true">0</sub>*\_*target*, given interference from pre-existing mobiles and other sources ([![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/z70EdP7czjCOqqhI-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/z70EdP7czjCOqqhI-image.png) and<a class="_ymio1r31 _ypr0glyw _zcxs1o36 _mizu1v1w _1ah3dkaa _ra3xnqa1 _128mdkaa _1cvmnqa1 _4davt94y _4bfu1r31 _1hms8stv _ajmmnqa1 _vchhusvi _kqswh2mm _ect4ttxp _syaz13af _1a3b1r31 _4fpr8stv _5goinqa1 _f8pj13af _9oik1r31 _1bnxglyw _jf4cnqa1 _30l313af _1nrm1r31 _c2waglyw _1iohnqa1 _9h8h12zz _10531ra0 _1ien1ra0 _n0fx1ra0 _1vhv17z1">![](blob:https://ecowiki.atlassian.net/4420a9a7-9611-48e9-a9ad-e564ac0a4df9#media-blob-url=true&id=1d63b543-c75f-468b-b5b7-329b14f81762&clientId=113268fe-fe5b-4bc3-8ff3-07965dbf1d18&contextId=contentId-493204&collection=contentId-493204) </a>[![image.png](https://wiki.cept.org/uploads/images/gallery/2026-04/scaled-1680-/dL5ybCP8a9ilJHAy-image.png)](https://wiki.cept.org/uploads/images/gallery/2026-04/dL5ybCP8a9ilJHAy-image.png) )
        - compute required transmit power of the mobile station
        - adjust the required transmit powers of the all existing mobile stations perturbed by addition of the new mobile station
        - continue the adjustment until the convergence of power control loop is achieved. A convergence criterion could be that the variation of two consecutive transmit powers of each mobile station is within a predefined threshold.
        - compare the number of active mobile stations, *Act\_MS*, with *N\_UL*
            
            
            - if *Act\_MS* ≥ *N\_UL* terminate the addition of a new mobile station in the network
            - else measure the average noise rise over the thermal noise η and compare it with the target noise rise limit η\_target
                
                
                - if η\_target is reached, terminate the addition of a new mobile station in the network
                - else add a new mobile station and go to step 2b

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