In Telecom network it is very often required to do the calculation for the network capacity.
This capacity is mainly required to do an analysis of the utilization of the network.
What is the current capacity of the network and what is the status of current utilization of the resources.
In 2G, 3G and 4G (LTE) in all cases we need to find out capacity of Voice (only for 2G) and Data (Especially for 3G & 4G).
The methods we are going to discuss can be used to do the calculation before implementation of a network or in existing network.
Here we emphasise mainly to do the capacity calculation for an existing network.
1. Voice Capacity Calculation (2G Network):
Voice capacity calculation of a site is an old method and most of us are already know it.
Here what we do, we do the capacity calculation sector wise, and then add up the sector values to get site wise total erlang capacity.
Now take the formula to do the calculation.
Formula for 1 Sector:
This is a calculation for 1 sector. The column names mentioned in the table to simplify the formula.
This is a calculation considering HALF RATE (HR) and with Adaptive Multi Rate (AMR).
If we work for FULL RATE (FR) then we can ignore the columns F, G and H.
Get the Erlang value w.r.t. the timeslot in column E from Erlang-B table.
Calculation for the whole Network:
If we have 5000 2G sites in our Network (Just taking a random example) then we have to sum up the erlang values of all the sectors. That will become the complete Erlang (Voice) Capacity or Equipped Erlang of the network.
Table: 1
Table: 2
This is an example of 2 sites each with 3 sectors. Likewise we can do the calculation for all the sectors of the network and finally sum up the column “G”. That will become the Erlang Capacity, Voice Capacity or Equipped Erlang of the existing network.
After getting this Capacity now it is easy to find out utilization of sites. We need to take the traffic data (Cell wise/Site wise) from system generated data and just divide Traffic by Capacity.
There is a report which gives Voice and data capacity of the network.
But sometimes the problem with the report is that, if in any case there are some sites which are down/hold due to some technical /Non-technical issue, capacity of those sites are not considered in the report.
2.Data Capacity Calculation (3G& LTE Network):
Data capacity of a site mainly depends on the available Bandwidth of the site.
Based on available Bandwidth below is the table which shows the maximum capacity of a site.
This value may change slightly case to case basis, but we consider these values as maximum capacity of a site for any calculation purpose.
Table: 3
Now we can see the below mentioned 6 sites.
Based on site wise technology and bandwidth we will get a total data capacity of a site.
This total data capacity of the whole network can be summed up to get the Data Capacity for the whole network, which may contains any no of sites.
This bandwidth wise data capacity is independent of frequency band.
For 10 MHz band we will get same 150 GB/site/day for 1800 band or 2100 band 4G sites.
Similar scenario for all other cases too.
Table: 4
Here we are not considering any data for 2G is because 2G data capacity is very low and it is based on the allocation of time slots for EDGE.
Moreover here we should not confused between data speed and data capacity. Here we are discussing only about data capacity of a site not anything about data speed or throughput.
Speed/Throughput altogether is a different concept and we may discuss in a separate blog.
Utilization:
Again for utilization as we did for 2G traffic. Here we have to find the actual site wise used payload and divide this value with the total data capacity.
This may be done site wise or for the whole network.
3.Bandwidth Capacity Calculation (2G,3G & LTE Network):
Here we are considering any telecom circle having the below mentioned frequency band along with allocated bandwidth.
These figures we are taking just as an example.
Frequency band and allocated bandwidth may vary based on telecom circle.
Table: 5
From the above table it is found that for a telecom circle “X” we have total 50MHz bandwidth.
In 4G total 35 MHz (900 band 15 MHz and 2500-TDD band 20 MHz).
Similarly for 3G in 2100 MHz band 5 MHz, and for 2G total 10 MHz in 1800 MHz band.
In this case for calculating site wise bandwidth first of all we have to find out site wise technology.
In a single site there may be any combination of technology.
For example we are considering the below mentioned technology combinations in any site and corresponding site bandwidth.
Table: 6
These technology combinations in a site may vary as per requirement.
Calculation for the whole Network (Data & Bandwidth)
In this way we can find site wise total bandwidth.
Once we get site wise data and bandwidth now we can do all types of permutation combination.
Like District wise, state wise, town wise requirement of data for capacity and Utilization calculation.
Showing of Bandwidth utilization is bit different from all other cases. Suppose we need district wise or town wise or may be any category wise Bandwidth utilization. In that case we can’t do the same calculation as like voice and data.
Please check the below mentioned table:
Table:7
If in a district named “X” has only 2G sites (here in this example showing 2G sites) then bandwidth utilization in that district will be 10 (refer Table:5,6 & 7)
In district “Y” there are 10 sites which are having all 2G+3G+4G+TDD technology.
So bandwidth utilization will be sum of all technologies i.e. 50 MHz (refer Table:5,6 & 7).
In district “Y” there may be other different technology sites too. Like 2G+4G 32 sites.
But we do not require considering utilization of district “Y” as 50+35. Instead it would be only 50.
Similar cases for all other combinations too.
Summary:
In telecom network capacity and utilization calculation is required to do very often.
As technology changes i.e. upgraded from 2G to 3G or 4G or may be site is loaded with TDD whole calculation for a particular site will be changed.
So this is an ongoing and necessary process to have an overall idea of the whole network.
Thanks for reading this blog.
Your feedback, comments, suggestions or like are highly appreciated.
Pranabjyoti Hazarika
BE | MBA | PMP | IoT-Certified