| 2017 | 2016 | |||
| Prepaid services to be provided (1) | 388,301 | 716,650 | ||
| Government grants (2) | 89,036 | 117,758 | ||
| Network swap (3) | 20,191 | 28,932 | ||
| Anticipated receipts | 22,627 | 18,554 | ||
| Deferred revenue from sale of towers (4) | 951,208 | 991,750 | ||
| 1,471,363 | 1,873,644 | |||
| Current portion | (480,431) | (812,340) | ||
| Non-current portion | 990,932 | 1,061,304 |
(1) This refers to top-ups of voice and data credit not yet used by customers, involving pre-paid system services, which are appropriated to income when customers actually use these services.
(2) Refers to the release of funds under the credit facility from the BNDES Investment Sustainability Program (“BNDES PSI”). The total sum of the subsidies granted by the BNDES through December 31, 2017 was R$203 million. This amount is being amortized according to the useful life of the asset being financed and appropriated to the “Other income (expenses), net” (Note 29).
(3) Refers mainly to the transfer of onerous contracts and reciprocal infrastructure of fiber optics (Note 11).
(4) Refers to amounts to be appropriated from sales of towers (Note 15).