At this time, the atmosphere in the conference room fell into a dead silence, as if even the air was stagnant, and there was no sound, Shen Wei, Zheng Baoyong and the others looked at Fang Chen with wide eyes and disbelief, they never thought that Fang Chen would ask such an unbelievable question that could not be completed at all.

A layer of fine beads of sweat appeared on Xiong Lejiu's forehead, his heart was pounding, his expression was evasive, he didn't dare to look directly at Fang Chen, as if he was burned by the hot light in Fang Chen's eyes.

What are you kidding, how could they possibly launch a mobile communication system that is more advanced than the GSM system?

If it weren't for Fang Chen's status being too high and his prestige being too heavy, he really wanted to directly stand up and point out how ridiculous Fang Chen's idea was, it was simply a fantasy.

If GSM is regarded as a textbook, they can only barely understand the content of this textbook at best, and it will take a year or even two years of experiments to really master this knowledge, absorb this knowledge into their own body, and integrate it with themselves.

But now Fang Chen actually asked them to develop a mobile communication that is more advanced than the GSM system, isn't this?

Anyway, they haven't seen it, saying that a student who has just read a textbook can immediately turn his face and make up a textbook that is better than the existing textbook, no matter how talented he is.

Fang Chen looked around at everyone, looking at this unbelievable and questioning face, the corners of his mouth couldn't help but curl slightly, and chuckled: "It seems to be a little difficult, and the requirements for everyone are a little high." ”

Shen Wei and Zheng Bao looked at each other, rolled their eyes in unison, and secretly complained in their hearts: "You still have points in your heart!"

"I have a little understanding of the 2G network in recent times, and I think it is not perfect, there are a lot of things that need to be improved, and I think that if these things need to be improved well, it should be possible to get a set of mobile communication systems that are comparable to the GSM system, or have surpassed, and now I will tell you some of my ideas, you can discuss with me. Fang Chen said slowly.

Hearing Fang Chen say this, everyone's faces became serious, it sounds that Mr. Fang's behavior as the boss of the company to explain the technology to these technicians is very ridiculous, isn't it usually the company's technical personnel to explain the technology to the boss?

But Mr. Fang is really an exception, Mr. Fang not only understands technology, but also Mr. Fang's technical level in this company is a mystery, not to say that I don't know Mr. Fang's technical level, but to say that Mr. Fang's technical level is high, and everyone doesn't know what Mr. Fang will be, like communication, electronics, everything.

All the companies in the entire Qingtian system are still circulating that Xiaobawang has just been created, there are no technical personnel, and the first generation of Xiaobawang game console is a legend that was successfully developed in less than two months under the leadership of Mr. Fang.

Moreover, after the acquisition of Luozhou Telephone Equipment Factory, the first small switch LT-240 installed in the Rural Telephone Bureau of Pishan Town, Luozhou City, was personally commanded and debugged by Mr. Fang.

Coughing, Fang Chen said: "Let's talk about the most important wireless communication rate first, now you should know that the GSM system uses time division multiple access technology, allowing multiple users to use the same frequency in different time slices, users quickly transmit, one after another, each user uses their own time slices, the advantage of this is equivalent to allowing multiple users to share the same transmission media." ”

"But Qualcomm has developed a code division multiple access technology, which is a multiplexing method in which multiple signals occupy only one channel, which greatly improves bandwidth usage, so that the transmission speed can be greatly increased to two to three times the usual speed. ”

"The transmission of information between users is forwarded and controlled by the base station. For duplex communication, one frequency is used for forward transmission and one frequency for reverse transmission, commonly known as frequency division duplex ......"

According to laboratory data, the transmission speed of this code division multiple access technology can reach up to 57.6kbps. ”

Xiong Lejiu was a little confused, although he didn't know where Fang Chen heard that Qualcomm had code division multiple access technology, but it sounded that the mobile communication system using this technology must be more advanced than the GSM system, and the transmission speed of 57.6kbps is really a bit terrifying.

But this technology is good, but it is Qualcomm's technology, and they can't get it even if they want to.

The following is the principle of code division multiple access spread spectrum, the transmitter is to encode the information code A (t) to be transmitted, first spread spectrum modulation of the pseudo-random code C (T), and then modulate the radio frequency, and the output signal is: s(t) = b (t) c (t). ”

where the rate (chip/s) of c(t) is Rc, and the rate (bit/s) of b(t) is Rb. In general, Rc is much larger than Rb, so the bandwidth of the modulated spread spectrum signal mainly depends on the c(t) bandwidth......"

Fang Chen wrote a long series of formulas on the blackboard in the conference room.

Looking at these formulas on the blackboard, Xiong Lejiu and the others covered their mouths, their eyes were as big as copper bells, they couldn't have imagined that Mr. Fang actually got the principle formula of code multi-address.

This kind of thing should be a secret of Qualcomm, but thinking about the equipment and instruments that Mr. Fang had shipped over before, a look of understanding flashed in everyone's eyes.

But all of a sudden, everyone understood why Mr. Fang emphasized the discipline of the meeting before the meeting, requiring them not to reveal a word, even drunk, and talking in their dreams, as far as the formulas that Mr. Fang wrote on the blackboard, it was indeed necessary to do so.

I also probably understand that Mr. Fang said that he had the confidence to make a GSM system that surpassed it.

Even Shen Wei had already regretted it at this time, he had known that Mr. Fang had said such a terrible thing, he should have driven away half of the people in this office, or even more than half of it.

And he's a little bit of a feeling that no one is at ease now.

After writing the formula of code division multiple access, Fang Chen then talked about general packet wireless service technology, enhanced data rate GSM evolution technology, and so on.

Fang Chen's speech lasted for nearly two hours before he barely stopped.

Looking at the inquisitive faces of Xiong Lejiu and others, Fang Chen suddenly had the feeling that he was the technical director in his previous life and gave the people below the principle of 4G communication.

However, compared with 4G, which is countless times more difficult, what he wrote on the blackboard can only be regarded as pediatrics, and any person who graduated from a communication major in his previous life can easily see that what he said is actually 2.5G, that is, the technology that is only applied on the second-generation semi-mobile communication network.

These formulas have long been the content of undergraduate textbooks for communication engineering.

2.5G is a wireless technology between 2G and 3G, is a convergence technology from 2G to 3G, because 3G is a very large project, the layers involved are many and complex, to move from the current 2G to 3G can not be connected at once, so there is a 2.5G between 2G and 3G.

Or 2.5G is the familiar 2G in China, or with the most primitive 2G broken technology, even sending a text message can't be smooth, there are more people, and the network will be blocked, not to mention what Internet access, it's a dream at all.

Generally speaking, Huaxia's mobile network is 2G following, 3G breakthrough, 4G synchronization, and 5G leading.

In the 2G era, Huaxia used the EU's GSM system, and in the 3G era, the third-generation mobile communication technology acquired by Datang Telecom from Siemens was barely enough to have its own 3G technology.

In the 4G era, Huawei, ZTE and other Huaxia companies have sprung up and truly developed a 4G mobile network belonging to Huaxia.

In the 5G era, it leads the world with 31% of declared patents.

But to be honest, Fang Chen was unwilling, he was finally reborn for a while, the switch era played behind people's butts, and the backward technology competition with Fujitsu and other international communication equipment giants was just that, as a result, 2G had to play behind people's butts, which was a bit too much.

And compared with 2.5G technology, the shortcomings of 2G technology are too big, once promoted, it will take less than two years to find a way to upgrade.

The most important thing is that Fang Chen feels that there is still a chance, it is only 1992, and it is still three or four years before Qualcomm is launching 2.5G, that is, is-95 mobile communication system, if in three or four years, his mobile communication laboratory sinks down, coupled with his guidance, it is not that there is no hope of launching 2.5G in front of Qualcomm, at least it must have the capital to compete with it, so as not to be beaten without the power to fight back.

And maybe, he has the possibility of doing a second Qualcomm.

Wrong!

It should be Qualcomm to be the second genius, right.

However, although he said this, thinking of Qualcomm, Fang Chen couldn't help but sigh lightly, many of the technologies he just talked about were invented and researched by Qualcomm.

The huge Qualcomm patent empire in later generations is actually from the 2.5G era, from the code division multiple access technology to the establishment of brick by brick, which is also the basis for Qualcomm to ask for high patent fees, and it is also the reason why many mobile phone manufacturers are still blackmailed by Qualcomm in the 4G era.

No way, the mobile phone always has to make calls, and to make a call, you have to use the 2G network, and with the 2G network, you can't get around Qualcomm, and you have to pay Qualcomm, which is a dead knot.

Xiong Lejiu fell into contemplation at this time, after Fang Chen's explanation and analysis of these technologies, he already felt that it was not impossible to achieve what Fang Chen said before to surpass the GSM system, but the problem was that these technologies were Qualcomm, how could they use them?

"Mr. Fang, even if we know the principle of these technologies, it seems that we can't say that they are our own things, right?" Xiong Lejiu couldn't help but ask.

As soon as these words came out, everyone stared at Fang Chen, this was definitely a problem.