https://www.almtwerinformatics.com/2019/04/29/%d8%a3%d9%82%d8%b3%d9%85-%d9%84%d9%83%d9%85-%d9%86%d8%aa-%d9%85%d8%ac%d8%a7%d9%86%d9%8a-4g-3g-2g-%d9%88%d8%a3%d9%86-%d9%84%d9%85-%d8%aa%d8%b5%d8%af%d9%82-%d8%ac%d8%b1%d8%a8-%d9%88%d9%84%d8%ac%d9%85/