private static void sortCellsByRadio() {
		String fileName = "/Users/Johan/Downloads/cell_towers.csv";
		try(BufferedReader br = new BufferedReader(new FileReader(fileName));
				BufferedWriter bw_UMTS = new BufferedWriter(new FileWriter("/Users/Johan/Documents/CellTowers/cell_towers_UMTS.csv", true));
				BufferedWriter bw_GSM = new BufferedWriter(new FileWriter("/Users/Johan/Documents/CellTowers/cell_towers_GSM.csv", true));
				BufferedWriter bw_LTE = new BufferedWriter(new FileWriter("/Users/Johan/Documents/CellTowers/cell_towers_LTE.csv", true));
				BufferedWriter bw_CDMA = new BufferedWriter(new FileWriter("/Users/Johan/Documents/CellTowers/cell_towers_CDMA.csv", true));
				) {

			String line = "";
			int totalCount = 0;
			int lines_UMTS = 0;
			int lines_GSM = 0;
			int lines_LTE = 0;
			int lines_CDMA = 0;

			System.out.println("Starting to read from file..");
			while((line = br.readLine()) != null) {
				totalCount++;
				if(totalCount%500000==0)
					System.out.println("Read "+totalCount+" lines..");

				String[] fields = line.split(",");

				if(fields[0].equals("UMTS")) {
					bw_UMTS.write(line+"\n");
					lines_UMTS++;
				}
				else if(fields[0].equals("GSM")) {
					bw_GSM.write(line+"\n");
					lines_GSM++;
				}
				else if(fields[0].equals("LTE")) {
					bw_LTE.write(line+"\n");
					lines_LTE++;
				}
				else if(fields[0].equals("CDMA")) {
					bw_CDMA.write(line+"\n");
					lines_CDMA++;
				}
				else {
					System.out.println("Do not fit: "+line);
				}
			}
			System.out.println("Done reading from file..\n");
			System.out.println("Read "+totalCount+" lines in total..\n");

			System.out.println("Wrote "+lines_UMTS+" to cell_towers_UMTS.csv");
			System.out.println("Wrote "+lines_GSM+" to cell_towers_GSM.csv");
			System.out.println("Wrote "+lines_LTE+" to cell_towers_LTE.csv");
			System.out.println("Wrote "+lines_CDMA+" to cell_towers_CDMA.csv");
			int sum = lines_UMTS+lines_GSM+lines_LTE+lines_CDMA;
			System.out.println("Wrote "+sum+" lines in total..");

		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}