Application of the hottest RFID in mobile base sta

  • Detail

Exploration on the application of RFID in mobile base station equipment management

the "elastic network construction" closely cooperating with market changes is the focus of mobile operators' communication network construction; It is an important means for the construction of "elastic network" to dismantle the network equipment to make up for the busy time and adjust the base station carrier. It is a major difficulty for the construction of "elastic network" to realize the real-time and accurate management of mobile base station equipment transfer

rfid (radio frequency tag) technology is widely used in retail, medicine, transportation and other fields, and is penetrating into various traditional industries. At present, material and equipment management is one of the fastest growing fields of RFID technology. Many enterprises can automatically, real-time and intelligently realize complex material and equipment mobilization management by integrating RFID tags with material and equipment management systems. In this context, China Mobile Communications Corporation Guangdong branch took the lead in trying to introduce RFID technology into the management of its base station communication equipment in China to achieve efficient, real-time and accurate equipment transfer management

this paper will mainly introduce the ideas, technical solutions and technical difficulties of RFID in communication equipment management of base stations

I. background and significance

Guangdong Mobile company carries out a large number of network equipment dismantling and busy work, base station carrier adjustment every year, and hundreds of thousands of new equipment are running. The above reasons cause the extremely arduous work of equipment transfer management and asset inventory! The traditional equipment asset management method of manual foreground and computer background can not meet the needs of the actual situation. At present, the front desk in the traditional way is still conducted manually. After on-site inventory, investigation, manual copying, entry and summary, China may also be trying to promote the development of the domestic waste collection industry. Only after participating can the collected equipment asset information be imported into the background computer database. A large number of manual participation in equipment asset management has caused problems such as complex process, long time, poor real-time performance, difficult management and high error rate. Finally, the utilization rate of equipment is reduced and the operation cost is increased

with the development of the company, Guangdong Mobile is facing the problem of how to carry out efficient and scientific management of a large number of communication equipment. Therefore, Guangdong Mobile hopes to realize remote, dynamic and real-time equipment asset data collection through RFID, replace the foreground manual data collection of the traditional asset management method, better combine with the background computer database, and form a fully intelligent equipment asset management system, so as to greatly improve the equipment utilization and reduce the transportation. 7. Hydraulic oil: it is necessary to often check the oil tank level and replenish oil in time; 1. Change the oil every 2000 to 4000 hours; However, it is important that the oil temperature should not exceed 70 ℃

II. General introduction to technology

rfid technology is one of the fastest-growing high-tech technologies in the 21st century. With the combination with traditional networks, RFID technology shows great market application potential and is called "IOT" and "second generation Internet"

rfid is the abbreviation of radiofrequencyidentification. RFID technology is an automatic identification technology that began to rise in the 1990s. RFID technology uses radio frequency to conduct non-contact two-way data transmission between readers and radio frequency cards to achieve the purpose of target identification and data exchange. Compared with traditional bar code, magnetic card and IC card, RF card has the characteristics of non-contact, fast reading speed, no wear, no environmental impact, long service life, easy to use, anti-collision function, and can process multiple cards at the same time. In foreign countries, RFID technology has been widely used in many fields, such as industrial automation, commercial automation, transportation control management, asset management and so on

1. system composition

the most basic RFID system consists of three parts

tag (RF card): it is composed of coupling elements and chips. The tag contains a built-in antenna for communication with the RF antenna

Reader: a device that reads (and can also write) tag information

antenna: transmit RF signal between tag and reader

2. standards and classification of radio frequency cards

at present, many companies producing RFID products adopt their own standards, and there is no unified international standard. At present, several standards available for RF cards are iso10536, iso14443, iso15693 and ISO18000. Iso14443 and iso15693 are the most widely used. These two standards are composed of four parts: physical characteristics, RF power and signal interface, initialization and anti-collision, and transmission protocol. Including 13.56MHz, 800MHz, 2.4GHz and other frequencies

at present, RFID products are mainly divided into two categories: active (active) and passive (passive)

* passive tag

the passive tag does not have a battery inside and can only work with external energy. When the electronic tag enters the working area of the system, the antenna receives a specific electromagnetic wave, the coil will generate induced current, and then supply power to the tag through the rectifier circuit. Passive tags have a short reading distance (several centimeters to five meters). For long-distance reading and writing, it is necessary to increase the transmitting power of the reading head and improve the receiving sensitivity to reliably identify. Passive tags have a long service life and low cost, but the price of the reading head is high

* active tag

the active tag has a battery inside. The tag actively transmits signals. The reading head can not transmit power. The tag power is generally less than 5MW. It can identify multiple target systems at the same time, and can identify high-speed moving targets of 100km/h. The identification range is adjustable from 1m to 100m. The service life of the active tag is affected by the battery, and the cost is high, but the price of the reading head is low

considering that the communication equipment of the base station has strong electromagnetic shielding, high power control requirements and the need for identification distance, we have chosen the active RFID tag as the application technology of base station asset management as the exploration direction

active RFID base station monitoring equipment consists of RFID readers (including microwave antennas and read-write controllers), electronic tags installed on communication equipment (such as carrier cards) and cabinet repeaters on metal shielding equipment (such as cabinets)

rfid reader/writer is the read/write controller of asset electronic tag and cabinet repeater, which is composed of encryption circuit, codec circuit and microwave communication controller. It uses the data exchange mode of RFID communication protocol and microwave wireless transmission means. After receiving the tag information, the data can be transmitted to the background system through GPRS, wired transmission and other means to realize remote, real-time and dynamic collection and analysis of equipment assets

electronic tag is a mobile device identification device with microwave communication function and information storage function. The asset electronic tag itself has a unique ID number, which can be used as a carrier for asset information identification and monitoring by binding the ID number with the background data of a specific asset

cabinet repeater is also a mobile device identification device with microwave communication function and information storage function. In addition to the function of electronic label, it can also be used as a shielding signal relay function

it is planned to adopt the active tag of 2.4GHz frequency. The RF card adopts advanced embedded microprocessor and realizes the functions of sleep, wake-up, decoding, coding, communication and information collision processing under the control of embedded software. Its features:

● readable and writable

● built in CPU, supporting program download

● intelligent two-way communication, intelligent i/o interface, external temperature, humidity, access control sensor and other signals can be input

● with key calculation and good security

● high efficiency built-in ultra-thin power supply, with a service life of 10 years

● high sensitivity, low transmission power (0.1MW ~ 1MW), only equivalent to 1% of Bluetooth power, almost no electromagnetic pollution harmful to human body

● the communication distance is generally 1m ~ 100m. Under special circumstances, the identification distance can be extended

● strong anti-interference, and can identify more than 200 markers at the same time

● fast data transmission speed, up to 1mbit/s

the label is about 5*5cm in size and weighs less than 20g. 3、 Technical difficulties and solutions

the technical difficulties of the system are mainly how to accurately, correctly and in real time obtain the ID numbers of all communication devices in a harsh use environment. Since most communication equipment are placed in each base station, the base station environment and equipment placement environment are relatively poor for wireless electronic products, which are mainly reflected in the following aspects

● electromagnetic compatibility problems

in order to avoid the impact on the normal operation of the base station, Guangdong Mobile has strict restrictions on the use of electronic equipment in the base station. For the difficulties of electromagnetic compatibility, the following methods can be adopted

stagger frequency: the frequency band of the base station equipment is between 880mhz ~ 915MHz and 1710MHz ~ 1785mhz. The planned active RFID frequency band is 2400mhz, avoiding the GSM frequency band. At the same time, it also has a certain protection bandwidth with the 3G frequency band

adopt spread spectrum method: adopt spread spectrum RFID tag to reduce power spectral density

power reduction: the active RFID tag can greatly reduce the system power. The passive tag generates current through induction and needs to emit strong power from the reading head. Using active tags, the power can be reduced to less than 3MW. At the same time, using a highly sensitive RFID reader can well solve the problem of electromagnetic compatibility in the base station

● the electromagnetic shielding oil circuit system has serious oil leakage or oil pipe rupture problem

many important equipment and plates in the base station need to be managed, but many equipment are placed in metal cabinets (such as base station carriers), so the electromagnetic shielding is relatively serious. This makes the RFID tag placed in the metal cabinet unable to transmit information to the reader/writer. The scheme of using signal repeater in the metal cabinet can solve the problem of electromagnetic shielding. In addition, the transmitting power of RFID tags in the cabinet can be further reduced by using repeaters, which is expected to be reduced to within 1MW

the repeater is about 5*15cm in size

IV. conclusion

according to the above ideas, Guangdong Mobile has begun to test and test the application of RFID in communication equipment management, and has obtained rich test data, laying a foundation for further application. If the technical demonstration is feasible, the remote, real-time, dynamic and intelligent communication equipment asset management can be realized after application, so as to greatly improve the equipment utilization and reduce the operation and management cost

information source: Automation System Engineering

Copyright © 2011 JIN SHI