Position positioning can be broadly divided into two broad categories:
1. GPS (Global Positioning System), GPS positioning is performed by receiving latitude and longitude coordinate signals provided by GPS satellites.
2. LBS (LBS–Location Based Service), and LBS calculates the location of the mobile phone by the difference in base station signals of mobile communication.
The two positioning businesses have their own advantages, but each has its own shortcomings:
1. GPS positioning: The advantage of GPS positioning is accurate. As long as it can receive the positioning signals of four satellites, it can locate the error within 5-10 meters. Since the GPS positioning is covered by at least 4 satellites at any time, the signal is well guaranteed, and because the satellite is condescending, the satellite clock and atmospheric interference are excluded, and the accuracy can be guaranteed to be several meters to several tens of meters. The disadvantage is that GPS is heavily influenced by weather and location. When the weather is bad, or under the viaduct/shade, or in the corner of the tall building, in the underground garage or in the open lower garage (or simply when the sky is not visible), GPS positioning Will be affected a lot, not even location services.
2. LBS positioning: The advantage of LBS positioning is convenient, because it is located by mobile phone, which has great significance for the energy consumption of the device and the extended standby time. In theory, as long as the signal difference between the three base stations is calculated, the location of the mobile phone can be determined. Therefore, as long as the user’s mobile phone is within the effective range of the mobile communication network, the location can be located at any time without being affected by weather, tall buildings, location, and the like. LBS positioning is subject to two restrictions:
(1) The position coordinate value obtained by calculating the difference of the base station signal is obviously inferior to the positioning accuracy of the GPS (the accuracy of LBS base station positioning varies from 500-5000 meters);
(2) The scope of use is narrow. Although LBS will not be affected by weather, viaducts or high-rise buildings, if the service range of the mobile phone is exceeded, or the number of base stations where the mobile phone is located is insufficient, LBS positioning cannot be performed;
(iii) The impact of the repeater on the base station data;
(4) The database update is not timely, and the mobile communication operator may change, add or delete the base station number at any time;
From this point of view, it is not suitable for field use. Mobile phone positioning is based on the existing mobile phone communication base station, which is greatly affected by the environment. Due to the scarcity of base stations, the mobile stations in the suburbs and rural areas are located in the range of 1000-2000 meters; the urban area is located in the range of 100-200 meters, but cannot be received. Where the cell phone signal is, it is impossible to locate it.
Source of data for LBS base station positioning:
1. Provided by a person within the mobile company;
2. Obtained through Google’s data interface, which is Google’s mobile device but unfortunately the interface has been closed;
3. Obtained through the network interface of the mobile communication carrier, but only limited to the public security and authorized SP operators. The interface is strictly regulated and needs to be paid on a per-time basis; and it must be approved by the owner; China Mobile uses It is Ericsson’s base station positioning system. Each location is charged on a per-time basis. It is the location data obtained from the switch side, not the base station data obtained from the mobile phone or the device side. For mobile communication operators, the revenue generated by the positioning is minimal. However, once the lawsuit for infringement of privacy has become a big problem, it is a big problem, so mobile communication operators are not enthusiastic about the base station positioning business.
The base station database includes the following data items:
1. MCC=460 China
2. MNC=0 China Mobile, MNC=1 China Unicom
3. LAC, CELL= is two base station data
4. LNG, LAT: is the standard latitude and longitude O_LNG, O_LAT: is the offset latitude and longitude, can be directly used for GOOGLE map
5. PRECISION: is the coverage (meter), radius, circle
6. ADDRESS: Chinese location description
7. DAY: inclusion time, used for batch export
LBS is not suitable for use in car positioning:
1. Poor positioning accuracy, large deviation (500-50000 meters accuracy);
2. It is the LBS that often does not receive signals in the field or only encounters one base station, and thus cannot locate;
3. The second is that in the high-speed exercise, if the base station switches too fast, it will affect the positioning effect.
LBS is suitable for:
Personal positioning
2. Long standby time and low precision positioning;
3. Indoor positioning;
Advantages of LBS:
1. Power saving; the energy consumption of the device can be greatly reduced through special design and algorithm; because the GPS module in the GPS positioning device consumes much more power than the GSM module (the GSM module standby mode can be 1-2 mA current) ); (and GPS operating current is 20-50 mA)
2. Suitable for indoor positioning, personal positioning; because the personnel positioning is mostly indoor work, life, learning, and the built-in battery to power the device. If the GPS positioning device is used indoors, there is a problem that the satellite cannot be found, and the GPS module does not stop working for the satellite signal, which further exacerbates the battery consumption.
Disadvantages of LBS:
1. Poor positioning accuracy, urban area 50-200 meters; suburban 1000-2000 meters positioning radius;
2. The base station data will be changed, and the mobile communication operator will adjust, temporarily increase or decrease the distribution of the base station as needed, especially the presence of the repeater (in the absence of a signal, pull the signal from other base stations to the The area is used to affect the accuracy of the LBS positioning; the database of the positioning system is not updated in time, which will affect the correctness of the positioning;
3. The LBS base station data is a secret of the mobile communication carrier and is generally not publicly available, or requires authorization or a per-charge to obtain. Therefore, it is not as convenient and easy to use as GPS positioning.
Post time: Sep-24-2019