Returning collection of data from webservice, how?

Question

I have writing asp.net webservice which would be accessed by android application. It actually takes string as parameter and then call store procedure to fetch several coordinates (lat, lon). Now i should store it in what and should return what so that android consumer can access rows of data from result being returned ?

public void FetchCoordinates(String FetchParam) 
    {
        String[] parts = FetchParam.Split(',');
        sqlCom.CommandText = "FetchCoordinates";
        sqlCom.CommandType = CommandType.StoredProcedure;

        sqlCom.Parameters.Add("@IMEI", SqlDbType.VarChar).Value = parts[0].ToString();
        sqlCom.Parameters.Add("@DateTimeFrom", SqlDbType.VarChar).Value = Convert.ToDateTime(parts[1].ToString());
        sqlCom.Parameters.Add("@DateTimeTo", SqlDbType.VarChar).Value = Convert.ToDateTime(parts[2].ToString());
        SqlParameter sqlParam = new SqlParameter("@result", SqlDbType.Int);
        sqlCom.Parameters.Add(sqlParam);
        sqlCom.Parameters["@result"].Direction = ParameterDirection.Output;

        try
        {
            sqlCon.Open();
            sqlCom.ExecuteNonQuery();

        }



        catch (Exception ex)
        {



        }

        finally
        {
            sqlCon.Close();
        }
    }

}

SP:

SELECT Longitude ,Latitude
         FROM Coordinates
         WHERE IMEI = @IMEI
         AND RecordedDateTime BETWEEN @DateTimeFrom AND @DateTimeTo

so how should i return LATITUDE, LONGITUDE collection from web service ?