What Should I Consider When Buying a Cell Phone?

Mobile phone, full name is mobile phone or wireless phone, usually called mobile phone. It was originally just a communication tool. In the early days, it was commonly known as Big Brother ^[1] . It is a portable phone terminal that can be used in a wide range. Bell Labs developed a battlefield mobile phone manufactured in 1940.

If we trace back, we will find that this

As the name implies, the type of mobile phone refers to the external type of the mobile phone. The more commonly used classifications are to divide the mobile phone into candy bar, folding (single screen, dual screen), slide type, rotary type, side sliding type and so on.

The mobile phone is a spare spare baby. When using it, it is relatively higher than any electrical products in your home in the event of accidents or premature degradation. If you have some basic knowledge of mobile phone first aid, do rescue first before sending it for repair, which can reduce losses and save your phone's life.

China's mobile banking business began in 1999. Like the experience of WAP, the early mobile banking had high barriers to use and poor user experience, while the bank was only content with the concept of publicity and did not really work on the content, which dampened the enthusiasm of some customers interested in the business. As a result, customers have more negative impressions on mobile banking, and the development of this business is not smooth. However, with the continuous progress of information technology and the gradual change of the bank's operating philosophy, the basic conditions of China's mobile banking are gradually maturing. Especially the rapid development of mobile phone terminals, the quality of wireless networks has been greatly improved, and the problems restricting the development of mobile banking were gradually solved. Since 2004, the mobile banking business has regained the attention of various banks. Several banks, including China Construction Bank and Bank of Communications, have launched their own mobile banking systems.

WAP mobile banking system architecture

WAP has been used for mobile Internet access in China since the late 1990s, but it was not sought after by the market. The fundamental reason was that WAP was based on dial-up mode at that time, the Internet speed was slow, the Internet access fee was high according to time billing, and the lack of mobile terminal support. Now, with the improvement of network conditions, the above obstacles that restrict the development of WAP technology are no longer present. Mobile 2.5G GPRS network and China Unicom's 2.75G CDMA1x network have cultivated tens of millions of WAP users, and a huge new network application is being popularized. At the same time, as the most important security issue for banking applications, it has been solved with the upgrade of WAP 1.x and 2.0 mobile phone terminals and WAP gateways.

Bank of Communications has just seen the maturity of WAP applications, and at the same time has fully absorbed the experience and lessons of mobile banking from other banks, focused on reducing the threshold for customers, and launched mobile banking based on WAP communication.

The Bank's mobile banking system uses a three-tier architecture system, which is the access layer (client mobile phone), business support layer (mobile banking service system), and banking business platform. Mobile banking customers' mobile phones use WAP access technology to interact with mobile banking systems through the gateways of their respective operators, and the mobile banking system interacts with various business systems of the bank through online banking gateways.

Bank of Communications Mobile Banking can connect China Mobile and China Unicom at the same time, with a wide geographical coverage and many applicable customers. Compared with other similar products on the market, it has obvious advantages such as rich functions, convenient operation, safety and reliability, and simple application procedures. At present, this mobile bank can not only provide personal financial services such as account inquiry, card-card transfer, credit card repayment, verbal loss, mobile phone recharge, etc., but also can be used for fund transactions and foreign exchange transactions. Public information services such as the price of buying and selling, market prices, consulting, K-line chart inquiry, stock and securities inquiry.

Bank of Communications Mobile Banking Security

In the Bank of Communications' mobile banking system, if the customer's mobile phone supports the WAP 1.x protocol, then the WAP 1.x architecture is used. Security) agreement. WTLS is a wireless version of the TLS security protocol. WTLS can guarantee the integrity, confidentiality and authenticity of data between mobile phones and gateways. The security between the gateway and the bank's WAP server is guaranteed by optional SSL (Secure Socket Layer) or TLS (Transport Layer Security Protocol).

SSL guarantees the integrity, confidentiality and authenticity of data between the gateway and the WAP server. If the customer's mobile phone supports the protocol of WAP 2.0, then the customer's mobile phone has directly supported various Internet communication protocols, and the security between all mobile phones and the bank's WAP server is directly guaranteed by optional TLS. This is transparent to the intermediate gateway (wireless IP routing). TLS guarantees the integrity, confidentiality and authenticity of data between customers' mobile phones and banks.

The Bank of Communications mobile banking system supports both of the above protocols and provides security guarantees based on this WAP security architecture. When customers conduct business transactions, the key sensitive fields of customer transactions are encrypted. For transactions between customers, key fields are encrypted using industry-recognized secure encryption algorithms to ensure the security of customer transactions. It is worth mentioning here that, due to the lack of understanding of new technologies, people often pay special attention to the security of mobile banking, and even stay away from mobile banking. In fact, due to the operator's encryption algorithm that encrypts the wireless transmission in the air, the key is stored in the user-side card and the network-side infrastructure equipment, and using multiple defense mechanisms such as slow frequency hopping technology. It is technically very difficult for network-side infrastructure (such as MSC / VLR, HLR, etc.) to achieve the purpose of stealing wireless signal content. The banking department as an application development unit will also pay enough attention to the security of mobile banking. Therefore, the current mobile banking has sufficient security guarantees from the application itself.

Problems facing mobile banking

From the current application situation of mobile banking, the most popular among customers are foreign exchange transactions with the highest real-time requirements. The transactions with the largest business volume are the purchase and redemption of money market funds, and the largest number of transactions are query transactions. . And mobile phone recharge transactions are highly appreciated by customers, and customers can fully feel the convenience of mobile banking when traveling or even abroad.

Compared with online banking and telephone banking, the unique advantages of mobile banking at any time have been highlighted. However, the real advantages of mobile banking are security and identity authentication. In fact, mobile terminals and wireless networks use a variety of technologies to ensure data security, which is more secure than online banking and mobile banking. What hasn't been fully realized yet is that because mobile terminals and mobile phone cards are the most personal electronic appliances, they have their own identity authentication function, and customers who use mobile banking's identity authentication function to solve large transfers and payment transactions. The problem of identity confirmation can greatly improve the security of such businesses, reduce transaction risks, and play an important role in promoting business development. In the long run, it is technically possible to ensure the security of the entire electronic transaction channel and authenticate the identity of the customer using a mobile phone terminal, and it is convenient and completely acceptable in terms of customers.

At present, the main problem of the development of mobile banking is that the entire mobile banking transaction process involves mobile terminal manufacturers, mobile operators, banks and customers, and the entire production chain is too long. At present, there are some irregularities in the support of data services for mobile phone terminal equipment and mobile operation equipment. Any incompatibility will affect the use of customers.

Rumor 1: Mobile phone radiation causes cancer ^[22]

Truth: There is currently no credible evidence that weak RF signals can affect human health. With current scientific knowledge, this radiation will not cause harm to the human body within a reasonable range. According to the safety ceiling established by the International Commission on Non-Ionizing Radiation, the safe radiation range to which the human body is exposed is 10 W / m2 ^[22] .

Rumor # 2: Calls on low battery levels are more radiant ^[22]

Truth: Generally speaking, the radiation strength of mobile phones is not related to the remaining power of the mobile phone, but to the signal strength of the mobile phone. This rumor is obviously confusing "one cell phone power" and "one cell phone signal". In the case of only one cell signal, the radiation intensity of the mobile phone may indeed be "1000 times as usual" ^[22] .

Rumor three: Charging mobile phones will explode ^[22]

Truth: The explosion of mobile phones in a row is frightening. The culprit of the explosion is actually a poor mobile phone charger. So try to use a manufacturer-approved charger and battery. In addition, playing a mobile phone during the charging process does cause the mobile phone to increase its heat. For safety, try not to play the mobile phone while it is charging ^[22] .

Rumor 4: The face of the caller was burned due to radiation from the mobile phone ^[23]

Truth: According to previous test results, the maximum temperature rise caused by mobile phone radiation on the head is 0.194 degrees Celsius. According to IEEE safety standards, the threshold for local temperature rise in the human body does not exceed 3.5 degrees Celsius. If the normal temperature of the human body is 36.5 degrees Celsius, the local temperature cannot be higher than 40 degrees Celsius, and the highest temperature caused by mobile phone radiation is less than 37 degrees Celsius, which is in a safe range. And humans can adjust their own local temperature through their body fluid flow. Therefore, the basis for the temperature increase caused by radiation is not sufficient ^[23] .

Although the heating caused by radiation is limited, it is not uncommon for the phone itself to become hot. There are two main reasons why your phone gets hot:

1) Playing the phone for a long time results in a large CPU and GPU load. Due to the small space of the phone, the limited heat dissipation capacity, and the battery itself will also heat up, which will cause the phone to become hot, and the temperature can even reach 50 degrees, naturally. Burns the skin;

2) Long-term use of the RF front-end, such as making a phone call. If the mobile phone signal is not good at this time, in order to ensure the quality of the call, the base station will increase the power output of the RF end of the mobile phone through power control technology, resulting in local heating of the RF front-end. Anyone who has used a mobile phone knows that a long time call will result in a high degree of fever in the handset handset part, coupled with the user holding the mobile phone close to the skin, making the heat dissipation unsatisfactory and causing burns ^[23]

Therefore, when using a mobile phone:

1) Try to answer the call in the area with good signal;

2) Reduce talk time in areas with poor signal quality;

3) If you call for a long time, use a wired headset to answer the call.

In fact, the most important thing is not to call for too long ^[23] .