The Propagation Delay information are (also) available in simple form of Performance counters.
These types of counters are available in pre-set ranges according to each vendor. The ranges vary from 1 Propagation Delay to several 'grouped' Propagation Delay.
For example in Huawei have some TA ranges in GSM, and other PD ranges in WCDMA (Note: Huawei calls these propagation delay counter s as TP instead of PD). For an 'ideal' scenario, we would have counters for 'each' Propagation Delay.
Actually, that's not what happens, because as we told before, they may be grouped into ranges. Note: the reason for this is not the case, but really too many ranges may even disrupt analysis.
TP (Propagation Delay WCDMA in Huawei) has 12 ranges.
In the above figure we have PDTA from 0 to 11.
- For TP_0 the UE is between 0 and 234 meters from NodeB;
- For TP_1 the UE is between 234 and 468 meters from NodeB;
- ...
- For TP_36_55 the UE is between 8.4 and 13.1 km from NodeB;
- And for TP_56_MORE the UE is more than 13.1 km from NodeB.
Note: See however that the amount of ranges here (GSM) is much bigger, and only begin to be grouped from 30 (from almost 17 km!).
With the counters organized in so different ways, be grouped by different ranges granularities, different distance (550 m for GSM and 234 m for WCDMA) it is very difficult to analyze the propagations, or rather, it is almost impossible to compare them...
And so what does we do, since we need to analyze the distribution of the UE's in a generic way, doesn't matter if it is using 2G or 3G?
The solution that we found in telecomHall was to make an 'approach', that is, a way to be able to see where we have more concentrated UE's, no matter if at the time they are using 2G or 3G. Even because, this 'distribution' among Technologies and Carriers depends on several factors, such as selection and handover parameters, and also physical adjustments of radiant system. But the 'concentration' of users does not depend on these factors: the total amount of users in a particular area is always the same!
To this, the module 'Hunter Propagation Analyzer' uses a methodology and 'particular' counters, allowing to do this approach: we have created a range, and called it PDTA. As the 3G (Huawei, which we are using as an example) has less ranges - only 12, we made the initial PDTA definition based on it. The result can be seen in the table below.
Of course this approach or 'methodology' is not perfect, but in practice the outcome is very efficient. In addition, if you need a more detailed analysis (for example if you need to know with more accuracy than the approach presented here) just look to the original table, which contains each counter in its standard range in original granularity.
For other vendors, the ranges may be different, but the methodology is always the same.
In Ericsson for example, the Propagation Delay WCDMA counter is 'pmPropagationDelay', and it is collected by the RNC just like in Huawei.
It has 41 bins, being the first to indicate the maximum delay in chips (Cell Range), and other (1 to 40) to inform the number of samples in the period, referring to the percentage of the maximum Cell Range.
When the UE try to connect at one point greater than the Cell Range it will fail.
Regarding to bins, the distribution goes from 0 to 100%, as the rule below:
- bin1: samples between 0 and 1% of Cell Range (for example, if the Cell Range is 30 km, bin1 has the samples between 0 and 300 m from NodeB);
- bin2: samples between 1% and 2% of Cell Range;
- …
- bin40: samples between 96% and 100% of Cell Range.
And the 'adjust' of PDTA can be done the same way, depending on your need.
Conclusion: Different vendors have different propagation counters, and in different formats - but the information is always the same! In all cases we can do the calculations that bring the analysis to the same comparison universe, with the benefits that we've illustrated above.
