Property and Equipment, Net
 12 Months Ended
Dec. 31, 2020
Property, Plant and Equipment [Abstract]  
Property and Equipment, Net Property and Equipment, Net
Property and equipment, net consisted of the following:
As of December 31,
20192020
(US$)
Cost:
Network equipment$6,976,107 $19,900,918 
Leasehold improvements1,089,970 1,950,310 
Electronic equipment1,170,866 2,232,004 
Furniture, computers and office equipment443,453 873,626 
Total cost9,680,396 24,956,858 
Less: accumulated depreciation(3,398,406)(8,203,008)
Property and equipment, net$6,281,990 $16,753,850 
Depreciation expense recognized for the years ended December 31, 2018, 2019 and 2020 were US$922,351, US$1,867,734 and US$4,457,981, respectively.