Key 

Performance 

Indicator

Network 1

Network 2

Benchmark 

Quality 

Bad Quality 

Traffic Load 

Quality enhancement 

Capacity increase 

measured as increased 

measured as 

quality for same load 

additional load at same 

quality level 

Figure 3.1: Spectral efficiency concept 

Thus, when comparing the spectrum efficiency or the spectrum utilisation of 

different networks, or when considering improvement in spectrum utilisation of 

the same network through engineering enhancements, it must be done 

against a common measure of quality. 

3.2.2  Quantifying Spectral Utilisation Efficiency 

The basic principle used by TRAI was to estimate the efficiencies of networks 

vis a vis theoretical benchmarks, practical implementations and 

enhancements possible by the use of advanced techniques. 

The first step is to have a measure of theoretical efficiency.  

The following terminology is used in this paper 

- 

Cell/Sector   the logical entities that have a single Broadcast Control 

Channel (BCCH) associated with each one of them. 

- 

Site   The physical location accommodation multiple or single cells / 

sectors 

- 

Packing density   The number of cells per Sq. kms 

3.2.2.1  Theoretical spectrum utilisation factor 

Theoretical values of spectrum utilisation are determined using plane earth 

with ideal, regularly spaced equi sized cells. 

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