https://purengom.com/2011/12/02/%eb%8b%9b%ec%bc%80%ec%9d%b4-%ec%8a%a4%eb%a7%88%ed%8a%b8%ed%8f%b0%ec%97%90-%eb%92%a4%ec%b3%90%ec%a7%84-lg%ec%9d%98-%ec%97%ad%ec%8a%b5-%ec%97%b4%ec%87%a0%eb%8a%94-lte%ec%99%80-%eb%94%94%ec%8a%a4/