The net carrying amount of telephone licenses and similar rights (2,153 million euros) and their useful lives are detailed below:
| 
  Type of license  | 
 Net carrying amount at December 31, 2017 (millions of euros)  | 
 Amortization period (years)  | 
 Amortization charge for 2017 (millions of euros)  | 
 |||||||||
| 
  TIM S.p.A.:  | 
 ||||||||||||
| 
  UMTS  | 
 537 | 18 | 134 | |||||||||
| 
  UMTS 2100 MHz  | 
 30 | 12 | 7 | |||||||||
| 
  WiMax  | 
 5 | 15 | 1 | |||||||||
| 
  LTE 1800 MHz  | 
 103 | 18 | 9 | |||||||||
| 
  LTE 800 MHz  | 
 720 | 17 | 60 | |||||||||
| 
  LTE 2600 MHz  | 
 79 | 17 | 7 | |||||||||
| 
  GSM (extension)  | 
 17 | 3 | 34 | |||||||||
| 
  Band 1452-1492 MHz  | 
 198 | 14 | 16 | |||||||||
| 
  Tim Brasil group:  | 
 ||||||||||||
| 
  GSM and 3G (UMTS)  | 
 165 | 15 | 53 | |||||||||
| 
  4G (LTE - 700 Mhz)  | 
 299 | 15 | 15 | |||||||||
| 
  
  | 
 
  
  | 
 
  
  | 
 
  
  | 
 
  
  | 
 
  
  | 
 |||||||