The business function and realization principle of mobile location

Currently, as one of value-added services provided by digital mobile communication network, mobile location service has already had a successful precedent in foreign countries, and has already passed the initial stage of development in China, and is showing good development momentum. In the coming 3G era, the positioning business will also be one of the key value-added services launched by operators, and its broad market prospects have aroused wide concern of mobile operators, service providers and manufacturers. --Editor

At present, with the development of wireless communication technology and the improvement of data processing ability, many mobile value-added services are developed. The mobile positioning business is one of the most promising business. At present, Japan, the United States, South Korea and Europe's mobile positioning business has made good progress.

At present, the main applications of mobile positioning include the following aspects. Personal safety and emergency relief. At present, our country's personal security and emergency relief alarm can only rely on dialing 110 or 120, which makes the user in an emergency (such as physical attack or emergency) of the alarm becomes very difficult. With mobile positioning, mobile phone holders only Click a few buttons, the police Center and Emergency center in a few seconds to know the location of the alarm person can provide timely relief. The United States has stipulated that all handsets must have a positioning alarm function after October 2001. Some European countries have also begun to use this. In our country can be used in the risk of personal attack alarm, special patient's guardianship and rescue, the only child position of guardianship and rescue, life encountered various difficulties in the need for help.

Anti-theft of motor vehicles. Compared with other kinds of anti-theft systems currently, mobile positioning Service System has outstanding advantages, including small system, light weight, can be placed in any location of motor vehicles and not easy to be found by car theft, not affected by occlusion, indoor and outdoor can achieve positioning; compared with GPS positioning, low cost, If the use of mobile phones as a positioning terminal price can be below the thousand yuan, the safety operation of the positioning system can be completely independently monitored by the relevant departments.

Group fleet, personnel and leasing equipment scheduling management. In many cases, group team and personnel managers need to timely dispatch of their vehicles and personnel to improve work efficiency, improve service quality, such as postal courier, Emergency maintenance services. The manager wants to reach the user's location in the shortest amount of time from the nearest customer's vehicle and personnel. With the help of mobile positioning business, managers can know the location of vehicles and personnel at any time, so they can quickly dispatch vehicles and personnel according to customer's requirement. Compared with GPS, the positioning technology used in mobile positioning service is characterized by that when the vehicle and the personnel enter the shelter or inside the building, the manager can still conveniently determine its position and carry out dispatching management.

Location-related information services. Mobile positioning service can provide a variety of information services related to the location. When users in unfamiliar areas want to know the nearest store, bank, bookstore, hospital, only a few seconds on the phone screen can appear the required location information. When users want to buy their favorite goods anytime, the positioning system and information Database can guide users to purchase. can also work with the Internet station to provide users with a wealth of information services. The business will also flourish in our country. (Computer science)

Logistics Management. such as the national flow of freight vehicles, train compartments, professional convoys such as armored vehicles, postal Express vehicles, such as the location of monitoring and management, reasonable dispatch vehicles, reduce no-load.

Advertising. The promotion of the above application will attract a large number of advertisers to insert the advertising business in the positioning business. The specific approach is to add 1-2 seconds before the user to receive positioning Information services display, can achieve better than the general paper advertising and even TV advertising effect.

Friendly and entertaining service. Users can use the positioning system at any time to know the location of friends, send greeting messages. You can play location-based games with friends.

Many people agree that location service is an important value-added business in the 21st century. For mobile users, the mobile location business is not only to understand their own or other location of personalized service, more important is related to each mobile user's own and property security. With the development of technology in the future, mobile positioning service will provide users with higher positioning accuracy, more convenient operation mode, more comprehensive location information. Mobile positioning service will also be more widely used.

From the perspective of technology implementation, there are several ways to provide positioning services, including through mobile phones, through the network to achieve and two ways of mixing.

Among them, through the mobile phone solution is mainly the combination of GPs to the mobile phone to provide positioning business, but because the tracking device antenna and send equipment expensive, power consumption, cell phone weight increased, while the mobile phone and GPS wireless connection will be affected by geographical location, surrounding environment and even the weather. All these factors make the application of mobile phone and GPS connection method have some influence. Therefore, the industry has put forward through the network to achieve the positioning of the way.

Network solutions usually have arrival angles (AOA), Arrival times (TOA), Arrival time difference (TDOA), and multiple path identification signs.

The AOA approach is to use each base station in several base stations to determine the distance from the user machine position, from 3 different angles to identify the user's position. Toa is a system based on the cell technology, which has high precision, but the cost is higher because the mobile phone and base station all need to expand the software and integrate. TDOA uses the cell location technology to set up a series of equidistant monitoring points in the city's grid map, which detects and receives signals from wireless mobile phones and sends them to the city's corresponding network for processing and service. Usually the detection and recording of each base station and mobile signal between the back and forth time with the accurate time sign, sent to the network server, the server will be the time stamp comparison, to determine the location of the user's mobile phone, the program requires at least 3 records, of course, more accurate records. Multi-Path identification sign, it is necessary to make a position identification sign distribution map on the city street map. When the signal arrives, the point where the signal is most consistent with the identification mark is the point closest to the user.

The main advantage of these network solutions is that they can be targeted at all mobile phones, without requiring users to purchase new handsets. But there are some drawbacks in the network to achieve positioning, it is mainly reflected in: each mobile company needs to establish its own monitoring stations; operators usually set towers and base stations on a straight line, which makes it difficult to obtain cell phone signals received by two or 3 base stations at the same time; Due to geographical reasons, Sometimes it makes the signals of transmission and reception different, such as the city's tall buildings, mountain peaks and so on will form the signal reflection and round-trip, resulting in positioning error.

Based on the above analysis, there is another way to be a mixed solution. The hybrid solution has the wireless assistant GPS and the enhanced Observation time difference (EOTD) and so on, overcomes the pure use GPS the shortcoming, like the battery life and with the satellite target line and so on the question, and the cost is also low. Therefore, the programme has received the attention of the industry. The hybrid solution consists of:

Wireless Assistant GPS solution. Wireless Assistant GPS Solution distinguishes the client from the server's handling of GPS signals, and the client's processing technology is reflected in the phone, and the server uses UNIX and NT software that works on the network. Because the client does less work than the entire GPS receiver, it works well in a congested environment and handles weaker signals, which, unlike the usual GPS, can work in an indoor or forest environment. Pure GPS Program Power consumption, wireless assistant GPS power consumption is small. Wireless Assistant GPS system does not need to change the network hardware, but need to increase network software. The main drawback of the Wireless Assistant GPS solution is that the user needs to purchase a mobile phone with an assistant GPS function.

EOTD Solutions. The program uses the software in the mobile phone to listen to the mobile network information and use the Position measurement Unit (LMU) to record the connection data from the network. The mobile phone sends the data read from the network to the central server in the network Center. The server compares the phone's information to the LMU data and calculates the user's location.

But we must also see that in addition to technology and cost, there are more factors affecting the development of mobile positioning business. Mobile Internet in mobile location technology, for example, has been questioned in many aspects, that is, when the positioning of the computing function in the network, the user's ability to control the positioning of the business will be weak, when users can not stop the network to determine its location, then the user's secret rights will be violated. There has always been a big debate about this point. Most users will feel comfortable if they can turn off positioning without shutting down his handheld phone. Based on this, there are many experts to support the implementation of positioning functions attached to the mobile terminal technical solutions.

With the development of mobile communication technology, especially the development of 3G, the technology realization of mobile location service will have more abundant means. Experts predict that the position technology based on the identification will be more advantageous in the future, especially the precision will be further improved. The mobile positioning business will therefore be more widely used, such as road, navigation, valuables transport and cash vehicles tracking and location-related billing and other value-added services.

Small information

What is mobile positioning

As one of the characteristic services of mobile communication system, location service has been considered as a bright spot in the future mobile value-added business. At present, the major mobile communication operators in North America, Europe and Asia-Pacific region have already opened mobile positioning business. By the end of 2004, the number of users using mobile location and location-based Services is expected to exceed 60 million, making it the second largest mobile business after voice. Mobile positioning can help individuals and groups of customers access to a variety of services and information based on location queries anytime, anywhere. Operators can use their own mobile network resources, combined with short message service system, GPS and geographic Information Service system (electronic map), with content and business providers, can provide individuals and group customers with rich and colorful mobile positioning application services. At present, the specific application of mobile location service can be divided into: Public Security Service, tracking business, personalized information service based on location, navigation service and location-based billing business.