WO2012139408A1

WO2012139408A1 - Method for reducing power consumption of high frequency wireless intelligent card

Info

Publication number: WO2012139408A1
Application number: PCT/CN2012/000112
Authority: WO
Inventors: 王海泉; 王李琰; 姜凤明; 顾万水; 唐德富
Original assignee: Wang Haiquan; Wang Liyan; Jiang Fengming; Gu Wanshui; Tang Defu
Priority date: 2011-04-14
Filing date: 2012-01-20
Publication date: 2012-10-18

Abstract

A method for reducing power consumption of high frequency wireless intelligent card, comprises the following steps: a terminal communication module of the high frequency wireless intelligent card is connected to a radio frequency module via IO interfaces, and the radio frequency module is controlled to switch between a sleep mode and a transceiving mode via these IO interfaces; parameters of the radio frequency module are initialized; the radio frequency module enters the sleep mode, and its duration is x; the radio frequency module enters the transceiving mode, its duration is y; during a cycle between the sleep mode and the transceiving mode, detect whether the radio frequency module receives a command or data of a card reader; if the command and/or data of the card reader is received, the high frequency wireless intelligent card starts to carry out card swiping transaction flow and its execution time is z. The present invention not only has the feature of low power consumption and the fast card swiping speed, but also the manner is simple, easy to actualize, and low in cost, and contributes to achieve the industrialization manufacture and large-scale popularize and application of the high frequency wireless intelligent card.

Description

TECHNICAL FIELD The present invention relates to the field of wireless communication technologies, and more particularly to a method for reducing power consumption of a high frequency wireless smart card.

Background technology

Book

With the popularization of mobile communication terminals, such as mobile phones, new applications such as e-wallets for mobile communication terminals, mobile phone access control, and mobile payment have become more and more popular.

The best way to satisfy these applications is to use the same or similar methods as existing RF card swipes. This requires the mobile communication terminal to exchange data with the consumer terminal or the access controller via wireless data communication like a radio frequency card.

Realizing mobile payment and other functions through mobile phones, it is necessary to implement near field communication functions on mobile phones. At present, there are mainly the following modes for implementing near field communication functions on mobile phones. The first mode is NFC mobile phones, which are integrated on existing mobile phones. NFC communication module (Near Field Communication) adopts the low frequency sensing mode of 13.56MHz, which is passive and requires the user to change the mobile phone. The second mode is to install the 13.56MHz low frequency sensing module on the mobile phone SIM, which needs to be modified. And there is a large induction circuit on the SIM, this mode can not be commercialized on a large scale; the third mode is to install 2.4G active high frequency induction mode on the mobile phone, which can effectively solve the penetration problem. The mode has been developed in Japan. The disadvantage is that users need a dedicated mobile phone. This is not suitable for users to change their mobile phone usage habits. The fourth mode is to integrate 2.4G active high frequency sensing module on SIM card (hereinafter referred to as RF- SIM card), this mode is very suitable for the user's usage habits. The fourth mode is being promoted in China, and it is the primary standard for mobile payment. However, in the current commercial situation, there are mainly the following shortcomings: The first is the adaptability of mobile phones to RF-SIM, and the second is RF-SIM. The cooperation between the card and the RF-SIM card reader device, the main performance The card reading speed is slow, the card reading distance is unstable, and the control card reading distance is difficult. For the same card reading device, some mobile phone reading distances are very close, some mobile phone reading cards are far away, and the third is the mobile phone screen after reading the card. The result is slow. The above shortcomings, mainly from the product, are mainly due to two problems. One problem is that the technology of the high-frequency wireless smart card is not good, the power consumption is high, the instantaneous current is large, and the card reading speed is slow, which causes many mobile phones to be unable to apply the high-frequency wireless. Smart cards, or because of the slow reading speed, the user experience is very poor, resulting in slow progress in promotion. Another question

The problem is the problem of the card reading device, which is mainly manifested in the lack of effective control methods for the card reading distance. In short, the products introduced by the existing technology are not only high in cost, but also have poor experience, which affects the experience and commercialization process of existing mobile commerce users, which is one of the obstacles to promote the application of the technology.

How to realize low power consumption of high-frequency wireless smart card, effectively control instantaneous current and realize high-speed card swiping has always been a technical difficulty in this field, and it is also the key to realize the industrialization of high-frequency wireless smart card. There are some patents that have studied related technologies, for example, patents.

200410036263.4 describes the basic hardware components of high-frequency wireless smart cards, including the elements, but does not explain how to achieve low power consumption and high-speed credit card; another patent 200710124354.7 elaborates on several physical structures of high-frequency wireless smart cards and The logic principle, but also does not involve how to reduce the high-frequency wireless smart card power consumption and achieve high-speed credit card and other important software and hardware technology.

Although in the prior art, there is a technical solution for adding a radio frequency chip to a mobile phone SIM card to expand the use function, so that such a wireless smart card having both a SIM card function and a radio frequency chip can have a wider application prospect. However, at the beginning of the research, the existing technical solutions only added low-frequency radio frequency chips to the SIM card of the mobile phone, and none of them involved or considered the increase of power consumption after the RF chip was added.

Because the low-frequency RF chip has low power consumption, if only the low-frequency RF chip is added, it has little effect on the power consumption of the wireless smart card, and it is still in an acceptable range. However, with the development of new technologies, new applications require more use of high-frequency RF chips, but the high-frequency RF chips consume a lot of power in their working state. If they completely ignore their power consumption, they still follow the SIM card on the mobile phone. Adding a technical solution for low-frequency RF chips to add high-frequency RF chips, The following problems exist:

1. The high-frequency RF chip consumes too much power, which causes the standby time of the mobile phone to be too short, which brings great inconvenience to the customer. When the SIM card is in the sleep state, the current is generally below 500 microamps, and the current is generally several milliamps. The standby time is much higher than the working time, so the average current should be below 1 mA. The standby time of the existing mobile phone is designed with full consideration of this factor. The fundamental principle is that the lower the working current of the mobile phone is, the better. The high frequency module of the high frequency wireless smart card has a large current during wireless transmission. Regardless of whether the high-frequency part operates in the receive mode or the transmit mode, the current is at least 7 mA or more, and can reach up to 12 mA. Together with the original phone IC card power consumption, the average current will exceed 8 mA. For a battery with a battery of 600 mAh and standby for 72 hours, the long-term operation in the wireless transceiver mode will directly reduce the standby time to half of the original 36 hours or even lower.

2, high-frequency RF chip power consumption is too large, the required input voltage is between 1.9V~3.6V, and the working voltage provided by the mobile phone to the SIM card is roughly three, g卩1.8V, 3.0V, 5.0V, high frequency The RF chip will not work properly due to low voltage, or it may be damaged due to excessive voltage, which greatly reduces the yield and compatibility, and cannot be used well with most existing mobile phones;

3. The high-frequency wireless smart card has an important operation flow in the production process, that is, the initialization operation of the card, such as writing the software system, writing the factory parameters, writing the initial key, etc., the existing conventional initialization method is The high-frequency wireless smart card is inserted into a contact card reader for reading and writing data, while the existing contact card reader has an operating voltage of 5.0V, and the input voltage required by the high-frequency radio chip is 1.9V~3.6V. Supporting, it is easy to cause damage to the high-frequency wireless smart card when writing the card, affecting the yield of the factory and the hidden dangers caused by the user.

For mobile communication terminals, especially mobile phones, low power consumption is an important technical requirement. Otherwise, the standby time of the mobile phone will be too short, the RF-SIM card will not be recognized, and even the power cannot be turned on. High-speed credit card is also an important indicator of mobile payment requirements. . Therefore, solving these two problems is the key to the technicalization of high-frequency wireless smart card industrialization. Summary of the invention The invention aims to provide a method for reducing the power consumption of a high-frequency wireless smart card. When used as a mobile communication tool, the high-frequency wireless smart card can transmit data through high-frequency transmission, and can conveniently realize the mobile payment function and the object. For networking applications, the high-frequency wireless smart card using this method not only has the characteristics of low power consumption, but also has fast card swipe speed, simple method, easy implementation, low cost, and is beneficial to realize industrialized production and large-scale promotion of high-frequency wireless smart cards. application.

Say

The technical solution of the present invention is as follows: A method for reducing power consumption of a high frequency wireless smart card, comprising the following steps:

1) The terminal communication module of the high-frequency wireless smart card is connected to the RF module through 10 ports, and can be switched between the sleep mode and the transceiver mode through the 10-port operation of the RF module.

2) RF module parameter initialization,

3) The RF module enters sleep mode, and the sleep mode lasts for X.

4) Then the RF module enters the transceiver mode, the transmission and reception mode lasts for y, and X > y is set.

5) The RF module repeatedly cycles between the above sleep mode and the transceiver mode.

6) Detect whether the RF module receives the command or data of the card reader while cycling between the above-mentioned sleep mode and the transceiver mode:

If you do not receive the command or data from the card reader, return to step 5;

If the command and/or data of the card reader is received, the high frequency wireless smart card begins to execute the card transaction process and enters the transaction execution time Z, which refers to the card reader and the high frequency wireless smart card as a complete Data exchange, security verification and data storage processes,

7) If the value of x+y is smaller, the faster the user continuously swipes the card. If the value of X divided by y is larger, the average operating current is lower, and the effect of reducing power consumption is better.

In the practical application, according to different application scenarios and the length of X time (determined by the complexity of the transaction), the values of χ and y can be adjusted differently, but X must be greater than y, and the value of y is ensured that at least one is received. Valid commands and data are fine. If the value of x+y is smaller, the faster the user can swipe the card continuously, if X is divided by y. The larger the value, the lower the average operating current, and the better the power reduction.

According to this method, the high-frequency wireless smart card has a very high working current in the flash card work, but the time taken is very short and has been satisfied.

The requirements of the GSM11.11 specification can be applied to ordinary mobile phones.

The invention not only has the characteristics of low power consumption, the card swifting speed is fast, but also has a simple method, is easy to implement, and has low cost, and is favorable for realizing industrial production and large-scale popularization and application of the high-frequency wireless smart card. BRIEF DESCRIPTION OF THE DRAWINGS The invention has the following figures:

Figure 1 Schematic diagram of a high-frequency wireless smart card

Figure 2 Schematic diagram of the software flow of the present invention

Fig. 3 Schematic diagram of another structure of a high frequency wireless smart card. DETAILED DESCRIPTION OF THE INVENTION The present invention will be further described in detail below with reference to the accompanying drawings.

The high frequency according to the present invention means that it is easy to penetrate the VHF band and the UHF band and the SHF band of the mobile communication terminal while avoiding the frequency band used for mobile communication to prevent collision.

The high frequency wireless smart card comprises at least two parts, a part is a terminal communication module for communicating with a mobile communication terminal (such as a mobile phone), the module is mainly used for authentication of mobile phone communication, parameter storage, etc., and another part is for The radio frequency module of the high frequency card is used for the function of the card payment and the access control of the mobile communication terminal. See Figure 1 and Figure 3 for the structure of the high-frequency wireless smart card.

In FIG. 1, the high-frequency wireless smart card 01 is provided with a terminal communication module 02 and a radio frequency module 03, and the terminal communication module 02 and the mobile communication terminal 04 (the mobile communication terminal can be a mobile phone) exchange data to implement a related function of the mobile phone communication, and the radio frequency Module 03 exchanges data with card reader 05 to implement RF card-related functions. In FIG. 3, the high-frequency wireless smart card 01 is provided with a terminal communication module 02 and a radio frequency module 03, and the terminal communication module 02 and the mobile communication terminal 04 (the mobile communication terminal can be a mobile phone) exchange data to implement a related function of the mobile phone communication, and the radio frequency Module 03 exchanges data with card reader 05 to implement RF card-related functions. The main chip of the terminal communication module 02 can use TG360 of EM company, the RF module 03 can use NRF24L01 as the main chip, and connect one IO pin 06 of TG360 chip to the CE pin of NRF24L01.

07, to achieve the data interaction function between the two.

The invention adopts a multi-time radio frequency module to sleep and briefly wake up alternate use book

The mode is to reduce the average current of the high-frequency wireless smart card to achieve low power consumption. In this way, the instantaneous current can also be controlled within the requirements of the GSM11.11 specification for mobile smart cards.

When the SIM card is in the sleep state, the current is generally less than 500 microamperes, and the current is usually several milliamps. The standby time is much higher than the working time, so the average current should be below 1 mA. The standby time of the existing mobile phone is designed with full consideration of this factor. The fundamental principle is that the average operating current of the mobile phone is required to be as low as possible.

According to the state of the art, the radio frequency module of the high frequency wireless smart card has a large current when it is wirelessly transmitted. Whether the RF part operates in the receive mode or the transmit mode, the current is at least 7 mA or more, and can reach up to 12 mA. Together with the power consumption of the communication module part of the original mobile SIM card terminal, the average current will exceed 8 mA. For a battery with a battery life of 600 mAh and standby for 72 hours, the long-term operation in the wireless transceiver mode will directly reduce the standby time to half of the original 36 hours or even lower. However, for the convenience of swiping applications, high-frequency wireless smart cards are not suitable for manual setting to manually switch between RF sleep mode and RF operating mode. This manual mode is not feasible in practical applications.

Although the RF module of the high-frequency wireless smart card has a large current during wireless transmission, since the transaction time of the card is short and the number of times is small, the consumed power does not have a substantial impact on the standby of the mobile phone. The speed of high-frequency communication is extremely fast, and the chips operating in the 2.4G band can basically reach a rate of more than 1 Mbit per second. This credit card trading working time It will be very short. For example, the average data transaction volume of a typical credit card transaction will not exceed 8000bit, plus the operation process overhead, the time will not exceed 100ms. Suppose a user brushes 50 cards a day, and all trading hours in 24 hours are 5 seconds. According to the average current of 8 mA, the power consumption of the card transaction is equivalent to reducing the standby time by 15 seconds for a mobile phone that can stand by for 72 hours. This loss is completely acceptable to users. Therefore, we only need to focus on reducing the work of RF modules for high-frequency wireless smart cards.

In mode, it is necessary to put the RF module in sleep mode as much as possible, rather than in the transceiver mode. And can be between RF sleep mode and RF transceiver mode according to certain conditions

Switch quickly.

During the RF sleep period, the current of the RF module is very weak, generally measured by microamperes. If the high-frequency wireless smart card can wait for the communication handshake with the reader, most of the time, the RF sleep mode and the short wake-up transceiver mode are used alternately. Reduce the average current of the high-frequency wireless smart card.

Usually, the waiting time for the RF card is usually between 100ms and 300ms. If it exceeds 300ms, the user's card experience will be very bad, which is an unacceptable indicator. Mobile phone access control, mobile payment and other application requirements also have this limitation. The card transaction process refers to the process of complete data exchange, security verification and data storage between the card reader and the high frequency wireless smart card in order to complete a specific application.

The invention uses the software setting to divide the workflow of the radio frequency module into three parts: x, y and z, wherein X represents the radio sleep mode time, y represents the short wake-up mode time, and z represents the completed work transaction after the wake-up handshake succeeds. Time, X time is greater than y time, y time should be as small as possible, but to ensure that a packet sent by a card reader can be completely received, the minimum required reliable time is the transmission time of 2 data packets. According to the rate of 1Mbit per second for high frequency communication and 500bit per packet, the minimum y time can be set to lms. The higher the high frequency communication rate, the lower the y time. For example, the working flow chart of the RF module 2, firstly, set the end of the card reader to the all-weather transceiver mode, repeatedly send valid commands and data information multiple times, start the high-frequency wireless smart card as the SIM mobile phone, and initialize the high-frequency wireless smart card. Including RF parameters of the RF module Initialization, after the RF module is initialized, the RF module enters the sleep mode. The duration of the mode is X, the X duration is over, and the RF module enters the RF module transceiver mode. The duration of the mode is y. Since the reader is always in the transceiver mode, this time. The high-frequency wireless smart card RF transceiver module detects whether there is a command or data of the card reader. Since the speed of the high-frequency communication is extremely fast, taking the 2.4G RF communication as an example, as long as the duration of y is greater than 1 ms, the high-frequency wireless can be ensured. The time slice of the smart card in the short wake-up mode

The data and commands of the card reader can be reliably received on y. If the card is not swiped, the command or data sent by the card reader is not received, and the high frequency wireless smart card RF module is transferred to the RF sleep book.

Mode, that is, enter X time again; if there is a card, it will receive the command or data sent by the card reader within y duration. At this time, the RF module of the high-frequency wireless smart card and the card reader shake hands successfully, and enter the time of the card transaction. z, depending on the complexity of the transaction, z is long and short, the more complex the transaction, the longer the z duration. Since the high-frequency communication is extremely fast, the transaction completion time (z duration) is usually completed within 100ms. When the transaction is completed, that is, the z duration ends, and the radio sleep mode is entered again, that is, the X duration. In this way, the high-frequency wireless smart card sets the radio frequency module to switch between the X duration and the y duration region. When the high-frequency wireless smart card has a swipe task, the RF module can detect whether a valid command of the card reader is received. Or data. If not received, re-enter X time. If it is received, it will enter the duration of z. According to the complexity of the transaction, the length of z is different. When the transaction is completed, it enters X time. Once the handshake is successful, both parties can complete the transaction of all data processes in a very short time. In practical applications, depending on the application scenario and the length of the X time (determined by the complexity of the transaction), the values of χ and y can be adjusted differently, but X must be greater than y, and the y value is sufficient to ensure that at least one valid command is received. And the data is OK. If the value of x+y is smaller, the faster the user continuously swipes the card. If the value of X divided by y is larger, the average operating current is lower, and the effect of reducing power consumption is better. The specific design of the software is shown in Figure 2.

The following examples illustrate the low power consumption of high-frequency wireless smart card RF card swiping through software and hardware on a high-frequency wireless smart card. As shown in Figure 3, the terminal communication module part selects the TG360 chip of Swiss EM Company, and the RF communication module adopts The NRF24L01 chip is used as the main chip. Connect one IO pin of the TG360 chip to the CE pin of the NRF24L01 chip. The security chip is programmed by software to continuously output high level and low level according to different proportions of time. The high level time is short and the low level time is long. The RF module can be set to most time RF sleep, short wake up transceiver mode alternate use. The way.

In practice, if the high-frequency wireless smart card is composed of NRF24L01 chip,

The RF module has a current of about 320 microamps during RF sleep and an average current of 8 milliamps in transmit and receive mode. When we wait for a handshake with the reader, we set it to every 60 books.

Within milliseconds, 4 milliseconds is in transmit and receive mode, ie the value of y is 4, 56 milliseconds is in sleep mode, ie the time of X is 56. Thus, the average standby current for the entire RF section is (8 mA x 4 ms + 320 μA x 56 ms) ÷ 60 ms = 0.832 mA. Estimated, it is equivalent to a standby 72-hour mobile phone with less than 7 hours of standby. It does not have much impact on the standby time of the mobile phone, and basically achieves the goal of low power consumption. High-frequency transmission is very fast, and for chips communicating on the 2.4G band, throughputs of more than 1Mb per second are generally achieved. Since the card reader adopts the continuous transmission mode, in the 4 ms transmission and reception mode time slice (y), with the high frequency rate of 2.4 G as an example, at least 8 data packets can be transmitted, so the radio frequency of the high frequency wireless smart card The module part is sufficient to receive at least one valid command and data. Once a valid command and data is received, the high-frequency wireless smart card and the card reader will successfully handshake, and then enter the normal RF operating mode (z) because of the high frequency. The data is very fast, and the working mode time (z) only lasts for a very short time, usually within 100ms. In addition to the waiting time of up to 60 milliseconds before, for the user experience, the total time for completing a card is x+y+z, that is, within 160ms, the user feels very good, making full use of the high-speed characteristics of high-frequency communication. Achieve high-speed credit card. In order to save the power consumption of the RF operation, only 60ms of the waiting time for the card is added. And this overhead does not affect the user's feeling of swiping.

In practical applications, depending on the application scenario and the length of X time (determined by the complexity of the transaction), the values of χ and y can be adjusted differently, but X must be greater than y, y As long as the value is sufficient to receive at least one valid command and data, if the value of x+y is smaller, the faster the user can swipe the card faster. If the value of X divided by y is larger, the average operating current is lower, lowering. The better the power consumption is.

According to this method, the high-frequency wireless smart card has a very high working current in the flash card work, but its occupation time is very short, and it has met the requirements of the GSM11.11 specification, and the ordinary mobile phone can be applied.

Book

Claims

Claim

A method for reducing power consumption of a high frequency wireless smart card, comprising the steps of:

2) RF module parameter initialization,

3) The RF module enters sleep mode, and the sleep mode lasts for X.

1