•  Area codes used in the surface maps and their positions:

Area codes and their GPS positions(GPS_X and GPS_Y):

• 1: X: 100,000-120,000; Y: 3,400,000-3,340,000
• 2: X: 130,000-180,000; Y: 3,380,000-3,330,000
• 3: X: 190,000-240,000; Y: 3,410,000-3,360,000 and X:200,000-230,000; Y: 3,336,000-3,340,000
• 4: X: 260,000-310,000; Y: 3,400,000-3,350,000 
• 5: X: 130,000-180,000; Y: 3,320,000-3,270,000
• 6: X: 90,000-120,000; Y: 3,280,000-3,250,000
• 7: X: 270,000-340,000; Y: 3,310,000-3,240,000
• 8: X: 100,000-120,000; Y: 3,220,000-3,190,000
• 9: X: 0-30,000; Y: 3,180,000-3,150,000
• 10: X: 170,000-200,000; Y: 3,250,000-3,220,000
• 11: X: 20,000-40,000; Y: 3,150,000-3,120,000