Analysis of positioning technology for indoor positioning using operator network

Location Based Services (LBS) is a service that obtains terminal location information through a positioning system and provides users with location-related information. In recent years, outdoor location services based on Global Navigation Satellite System (GNSS) have been widely used in daily life, which facilitates people’s daily life and creates huge commercial value. However, indoor location services are still not widely used because buildings block satellite positioning signals.

1 Introduction

Location Based Services (LBS) is a service that obtains terminal location information through a positioning system and provides users with location-related information. In recent years, outdoor location services based on Global Navigation Satellite System (GNSS) have been widely used in daily life, which facilitates people’s daily life and creates huge commercial value. However, indoor location services are still not widely used because buildings block satellite positioning signals.

With the continuous development of indoor positioning technology, indoor location services have been gradually applied in the fields of public safety, personnel loss prevention, commercial entertainment, unmanned equipment, smart logistics and special population care, as shown in Figure 1.[1]. Among them, in the field of public safety, indoor location service can provide route guidance for the evacuation of trapped persons and the dispatch of rescue personnel; in the field of personnel loss prevention, indoor location service can locate and monitor the location of children to reduce the occurrence of criminal behavior; commercial entertainment field , indoor location services can provide mobile phone users with target store navigation, support virtual reality and augmented reality games based on location services; in the field of unmanned equipment, indoor location services will provide them with indoor navigation capabilities to realize automatic parking in indoor parking lots of unmanned vehicles In the field of smart logistics, the indoor location service realizes the location supervision of dangerous goods and improves the efficiency of cargo management; in the field of special population care, the indoor location service greatly reduces the cost of unsupervised management of the elderly.

Analysis of positioning technology for indoor positioning using operator network

Figure 1 Application areas of indoor positioning services

According to forecasts, the market size of indoor location services will exceed 2 trillion in 2020. At present, the indoor location service has shown a huge market demand. In the future, with the improvement of the market and the popularization of indoor positioning technology, the location service market will achieve rapid growth. As mobile communication service providers, operators naturally have the ability to build large-scale networks and are unwilling to miss the huge market for indoor location services. However, at present, there is no suitable large-scale indoor positioning and network construction plan for the 2018.9 Internet World 35 Academy business. The reasons for this situation include both technical factors and market factors. This paper will conduct research on the indoor positioning technology and application based on the operator’s network, and propose two indoor positioning system solutions, which solve the problems existing in the existing technology and meet the operator’s low-cost and high-precision indoor positioning network construction requirements. At the same time, this paper will also introduce the indoor positioning accuracy test results, indoor location navigation and WeChat red envelope business, and analyze the technical advantages of operators in indoor positioning-based applications.

Analysis of positioning technology for indoor positioning using operator network

Figure 2 Indoor positioning system based on passive room division

2. Analysis of the status quo of indoor positioning technology

2.1. The working principle of mainstream indoor positioning

Facing the huge market for indoor positioning services, Internet companies have begun to actively deploy Bluetooth and WiFi indoor positioning technologies, and operators have also begun to explore indoor positioning technologies based on communication base stations.[2-4]. in:

1) Communication base station positioning: This technology measures the signal sent by the mobile terminal on the network side, and performs position calculation. The positioning process is that multiple communication base stations simultaneously detect the signals transmitted by the mobile terminal, send each received signal carrying characteristic information related to the location of the mobile terminal to the information processing center, and calculate the location of the mobile terminal. The positioning algorithms used in the communication base station positioning technology include Cell ID positioning, signal field strength triangulation positioning, signal field strength fingerprint database positioning and time of arrival triangulation positioning.

2) WiFi positioning: This technology has become very popular due to the popularity of WiFi networks. Hotspots (APs) will be deployed indoors, and each wireless AP has a globally unique MAC address. The WiFi terminal can scan and collect the surrounding AP signals under program control, and obtain the MAC address and signal strength broadcast by the AP. The MAC address can determine which AP it belongs to, and the signal strength can be used to calculate the distance between the terminal and the AP. The WIFI terminal sends these data to the location server, and the server can calculate the indoor location of the device and return it to the user device. The positioning algorithms used in the WiFi positioning technology include Cell ID positioning, signal field strength triangulation positioning, and signal field strength fingerprint database positioning.

3) Bluetooth positioning: This technology is currently deployed more, and it is also a relatively mature technology. There is not much difference between Bluetooth and WiFi. In 2013, Apple released the iBeacon protocol based on Bluetooth 4.0 Low Energy Protocol (BLE), which was mainly aimed at retail applications and attracted widespread attention. The normal operation of the iBeacon Bluetooth beacon technology requires the Bluetooth beacon hardware, the application on the smart terminal, and the application background on the cloud to work together. The beacon broadcasts its ID to the surrounding through Bluetooth, and the application on the terminal will take corresponding actions after obtaining the ID of the nearby beacon, such as extracting the location information and marketing information corresponding to the ID from the cloud background. The terminal can measure the received signal strength at its location to estimate the distance to the beacon.Bluetooth Figure 1 Application Field of Indoor Positioning Service[1] 2018.9 The positioning algorithms adopted by Internet World 37 Academy’s positioning technology include Cell ID positioning, signal field strength triangulation positioning, and signal field strength fingerprint database positioning.

2.2. Mainstream indoor positioning algorithms

Mainstream indoor positioning algorithms can be divided into Cell ID positioning algorithm, signal field strength triangulation positioning algorithm, signal field strength fingerprint library positioning algorithm and time of arrival triangulation positioning algorithm. in:

1) Cell ID positioning algorithm: The positioning accuracy is low, which is 1/2 of the distance between the positioning base stations. According to the field strength of the downlink or uplink signal, it is determined that the user belongs to the positioning device. The indoor position of the user is estimated according to the indoor position of the user’s home positioning device.

2) Signal field strength triangulation positioning algorithm: The positioning accuracy is moderate, which is 1/3 of the distance between the positioning base stations. Calculate the path loss according to the field strength of the downlink or uplink signal, calculate the distance (difference) between the positioning device and the user according to the path loss, and calculate the indoor position of the user according to the principle of triangulation.

3) Signal field strength fingerprint library positioning algorithm: the positioning accuracy is relatively high, which is 1/4 of the distance between the positioning base stations. Collect the downlink or uplink signal field strength fingerprint database, measure the user’s signal field strength according to the downlink or uplink, match the measurement results in the fingerprint database, and estimate the indoor location of the user.

4) Arrival time triangulation positioning algorithm: the positioning accuracy is relatively high, which is 1/4 of the distance between the positioning base stations. Several positioning devices measure the uplink signal delay of the same user, calculate the distance (difference) between the positioning device and the user according to the delay, and calculate the indoor position of the user according to the triangulation principle.

2.3. Comparative analysis of mainstream indoor positioning technologies

The comparative analysis of three mainstream indoor positioning technologies is shown in Table 1.

Analysis of positioning technology for indoor positioning using operator network

1) Positioning method: The communication base station positioning technology is passive, that is, the user does not need to open any application program, and the indoor positioning function is completed when the terminal accesses the communication network, which is suitable for operators’ big data analysis. WiFi and Bluetooth technology are active, that is, users need to turn on WiFi and Bluetooth, and sometimes need to open an application to complete the indoor positioning function, which is suitable for personal applications, such as indoor positioning and navigation.

2) Positioning accuracy: The positioning accuracy of the three mainstream indoor positioning technologies is mainly determined by the positioning algorithm and the distance between the positioning base stations, that is, the more complex the positioning algorithm, the higher the positioning accuracy, the denser the positioning base stations, and the higher the positioning accuracy. Base station density also determines the cost of indoor positioning.

3) Equipment cost: According to the current market quotation analysis, the cost of communication base stations is the highest, reaching the thousand yuan level, the cost of WiFi equipment is one hundred yuan, and the cost of Bluetooth equipment is ten yuan. In terms of equipment cost, Bluetooth positioning technology has obvious equipment costs. Advantage.

4) Maintenance cost: The communication base station has routine inspection and maintenance operations, and the maintenance cost of this positioning technology is the lowest, while WiFi and Bluetooth devices are independent devices, and special personnel need to be arranged for regular maintenance. Therefore, the maintenance costs of these two positioning technologies are Highest.

5) User security: The security of communication base stations and Bluetooth positioning technology is relatively high, while that of WiFi technology is relatively low. Due to the low threshold of commercial WiFi technology, building a false WiFi environment in public places to transmit signals to induce users to connect and use it is technically very easy to do, creating huge risks for hackers to obtain user accounts and passwords.

6) WeChat Shake: Among the three positioning technologies, only Bluetooth supports WeChat Shake. Shake on WeChat means that when a user walks to the door of a business, turn on Bluetooth and shake the surroundings with WeChat to get information such as coupons and advertisements. It is currently widely used in the O2O field.

7) Terminal adaptation degree: The communication base station positioning technology only supports specific operator terminals, which has certain limitations, while WiFi and Bluetooth! Figure 3 Networking diagram of indoor positioning system based on passive room division, Figure 4 positioning system

Analysis of positioning technology for indoor positioning using operator network

Figure 3 Networking diagram of indoor positioning system based on passive room division

Analysis of positioning technology for indoor positioning using operator network

Figure 4 Positioning system based on active room division

3. Research on indoor positioning technology based on operator network

The communication network has good coverage, but because the existing communication network mainly faces communication needs and is not optimized for positioning needs, the communication network is in a marginal position in the field of positioning[5]. At present, the operator’s indoor communication network is mainly divided into two categories: passive room distribution, represented by passive DAS, and active room distribution, represented by distributed skin stations. Among them, the passive DAS is composed of the RRU source and the passive room sub-antenna. Since the passive room sub-antenna cannot be independently distinguished, the passive DAS does not have indoor positioning capability. The average distance between distributed pico-base stations is 30-40 meters, and the positioning accuracy is greater than 10 meters, which cannot meet the needs of indoor positioning. If the indoor positioning accuracy of 5-7 meters is to be achieved, the distance between pico-base stations needs to be reduced to 20 meters, which greatly improves indoor communication. network construction costs. Therefore, operators currently do not have indoor positioning technology that can be applied on a large scale.

At present, indoor positioning applications are mainly divided into two categories, active positioning applications and passive positioning applications. Among them, the active positioning application is represented by indoor positioning and navigation. The user actively opens the application APP to call the positioning and navigation software, which is suitable for using Bluetooth positioning technology. The passive positioning application is represented by indoor big data analysis. The operator collects a large amount of user information to analyze the profile of the characteristic population, and it is suitable to use the communication base station positioning technology. Next, the carrier-grade indoor positioning system for passive room and active room is introduced in detail.

3.1. Indoor positioning system based on passive room division

The indoor positioning system based on passive room division proposed in this paper is shown in Figure 2, including a baseband unit, a near-end signal source, a smart room division antenna and an independently mounted Bluetooth beacon. Among them, the near-end signal source can be implemented by a high-power macro station or a medium-power micro station in practical application, and a Bluetooth gateway is integrated inside it. The smart room sub-antenna is a room sub-antenna with a built-in Bluetooth beacon, which is connected to the near-end signal source through a radio frequency feeder, and realizes power supply and control based on a DC passive network. The independently mounted Bluetooth beacon is used to improve the indoor positioning accuracy and additionally, and communicates with the Bluetooth beacon built in the smart room sub-antenna to achieve management and control capabilities.

The network diagram of indoor positioning system based on passive room division is shown in Figure 3. The near-end signal source has two RF output ports, each of which is connected to a 4-centimeter. Divide the antennas into the four smart rooms. Based on Bluetooth positioning technology, the positioning accuracy that this solution can provide is determined by the distance between the smart room sub-antenna and the independently mounted Bluetooth beacon.

3.2. Indoor positioning system based on active room division

The indoor positioning system based on active room division proposed in this paper is shown in Figure 4, including baseband unit, routing unit, remote source, smart room division antenna and Bluetooth beacon. Among them, the remote signal source can be realized by the pico base station in practical application, and the bluetooth gateway is integrated inside it. The smart room sub-antenna is a room sub-antenna with built-in Bluetooth beacon, which is connected to the remote source through the RF feeder, and realizes power supply and control based on the DC passive network. The independent bluetooth beacon is used to improve the indoor positioning accuracy and is additionally supplemented. It is connected to the remote signal source through the network cable, and has power supply and control capabilities at the same time.

Analysis of positioning technology for indoor positioning using operator network

Figure 5 Networking diagram of indoor positioning system based on active room division

Figure 5 shows the network diagram of the indoor positioning system based on active room division. Each remote signal source has two RF output ports, each of which is connected to an external four-centimeter, and then connected to four smart room division antennas. Based on Bluetooth positioning technology, the positioning accuracy that this solution can provide is determined by the distance between the smart room sub-antenna and the independently mounted Bluetooth beacon. In addition, each remote source can also provide indoor user big data collection and analysis capabilities.

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