Typical Usage

Here are described some of the typical usage of Prismo Simulator.

QOS maps

It is often useful to produce maps of provided QOS (quality of service). They can be used:

• for marketing purposes,
• to identify weak areas in the network

One common example of such QOS map is the offered throughput on HSDPA services.

In HSDPA, offered throughput depends on the signal quality, but also on the number of concurrent users sharing the HSDPA channels and the scheduler algorithm. Prismo Simulator models the various possible schedulers and reproduces the traffic as measured in the real network.

Other type of QOS map can be plotted such as:

• Map of CQI in HSDPA, showing thus maximum achievable throughput
• Map of Call Failure ratio, and their precise failure reason
• etc.

Simulated EcIo maps

Map of EcIo is a traditional figure used by radio engineers for planning the UMTS network. It measures in a simple way the network signal quality and interference level. Such maps depend strongly on the power load on each cells.

Traditionally one uses fixed dedicated value for these power loading, thus leading to suboptimal EcIo map. In addition aggregated maps on multiple carrier is not possible.

Prismo Simulator allows to take into consideration the traffic coming from measurement on the real network, replicates it on the simulated environment, and then produce relevant EcIo maps using the simulated power load on each cell. These maps are thus derived directly from the simulated connections.

Producing aggregated maps on multiple carrier is also possible with this method.

Simulated EcIo (exported map in raster BIL)

Atoll EcIo Map (using average cell load from simulation)

Dimensioning of Cell/Site resources

Sites have limited resources, such as cell power, channel elements and Iub capacity. Prismo captures the statistics and distribution of these resource usage on a per cell and per site basis. It also keeps statistics on any call failure due to limitation of these resources.

Using these data, one can derive the correct dimensioning to be used, reduce capital cost and improve quality.

Histogram view of CE usage per site

Graphical view of CE usage per site

Continuous planning

Prismo Simulator allows to lock the simulation on the traffic measured in live network. In some way this performs a calibration to the real network.

By increasing the traffic load according to marketing expectation, maps of future QOS are created.

This helps forecast the network quality, and identify areas of weakness before the changes actually take place. Any appropriate action can then be planned ahead of time.

Prismo Simulator thus complements reactive optimization techniques based on post-processing of drive test or KPI measurement.

To accommodate these traffic changes, it is often necessary to add new sites and plan again the network. Many design choice are left open when performing these network upgrades, such as site location, antennas azimuth, modification to existing sites, etc..

Prismo Simulator also complements existing methodologies based on manual planning or ACP (Automatic Cell Planning) tools. It allows to quickly validate the new network setup before implementation.

Design study and guidelines

Prismo Simulator can be used to run studies for comparing various network design options. It provides a quick and easy way to test various scenarios, derive statistical results and QOS maps, and find out the best rules which can be applied in a systematic way.

These studies can then lead to guidelines for network deployment.

Examples of such studies are:

• how to deploy HSDPA on multiple carrier networks: should HSDPA be enabled on a dedicated carrier, or is it better to share a carrier for both HSDPA and R99 traffic
• what is the best strategy in deploying bi-layer micro/macro with 2 or more carriers.
• what values to use on key open parameters
• etc..

Analyzing RRM strategies

Prismo Simulator implements various vendor RRM modules. New modules can be added to the simulator as of customer request.

The simulator can be used for:

• comparing various vendor RRM strategies, and evaluate their effect on overall network quality
• understanding the effect of the main parameters of the RRM algorithms, and possibly tuning them
• etc..

Providing input to link level simulations

For R&D engineers, Prismo Simulator can be setup to output detailed statistics of mobile signal and interference data for each interfering cell. These data can be used as input of link level simulation for performing detailed analysis of receiver algorithms and performance.

As an example, such studies have been performed to evaluate beamforming performance in real network configuration.