"Editor's note" Reky zhou,C114 belongs to communications Home Forum users. C114 communications network in China made by the paper. About involved in the network model, Lei Feng can refer to network article: why we are using "castrated" cell phone?
Before starting this topic said the history of wireless communication
For ease of understanding, starting from the Terminal side first, that people couldn't use the phone, so that is easy to understand, after all, most people only use mobile phones, communications networks wireless networks is going on is not clear, nor care. Communications network in order to support your application, there is behind the communication network wireless network support, not anything different from your cell phone with a brick. And mobile phone demand, to use the fashionable word is your pain points, and influences the direction of development of communication networks. So from here said, I believe we all are relatively easy to understand, after all, most people are not communication experts.
Do you remember BP machines, mobile phones, used to watch Hong Kong movies behind the gangster has a phone's younger brother, that phone like a brick, thief thief bulky, it's big brother, called a peg a envy. Early hand-cranked telephones, magnetic phone, of course, it is estimated that most people have not seen real, but have seen in war movies, and now mobile phones with Internet access can see the film to take pictures we can navigate, almost anything, this years developments in particular the development of wireless communication, the speed faster than we can imagine. Estimating is a science-fiction film in the case before, now we realize, electronic technology is the fastest-growing a human industry in just more than 100 years more than we can imagine.
(Big brother of the year)
From the original 1973 United States Motorola invented analog wireless communication, launched the world's first wireless communication terminal, also known as saying cell phones, at the end of the function, represented by NOKIA, and now Apple's Smartphone era. Terminal and more powerful, is no longer a simple call, but a personal mobile terminals, mobile Internet access anywhere, anytime. Terminal upgrades and faster, today 3G tomorrow 4G, new term, new concepts and new technologies seem to be there every day, forcing mobile phone users have always new machines, or behind the times.
Apple 4 comes out a few years ago experienced a high-speed data service, 3G, to tell the truth often connect error, speed is not as fast as advertised, the cost often exceeds. It's not just a few years, and said to 4G, remember 3G4G posters on the face comparison chart? For everyone to see, how much exaggeration.
Facial skin faster that 4G are out of shape. Since 4G deals, a joke circulating on online –
"4G environment, if you forget to turn off the flow when you sleep, House came to move the next day. "
This rate is how fast. Results 4G I'm still useless, now promote 5G, this update is too fast. Internet speed faster than the 4G of the 5G known as thousands, and speed estimates can not imagine this, downloading a film estimated to kill.
From a technical point of view, first-generation analog cellular telephones to digital GSM is a revolutionary technical leap, analog communication anti-jamming worse machine integration and intelligent is not high, known as the mobile phone can be knocked dead means it is too big and unwieldy. The GSM in the age of digital communication, representative such as NOKIA Mobile phones, because of computer and software technology has been greatly promoted, integration has greatly improved, the mobile phone has done a very nice, and greatly strengthened due to the interference of digital communication and security capacity, call and have a better safety. Instantly improves the user experience, rapid development and popularization of GSM.
Think back to that phone sold is called a fire, NOKIA is taking advantage of the tide rising, growing into an amazing company of global attention, global communications sector cellular telephones.
Write here think of Zhejiang before a show: a man of 93 years spent 17,000 RMB to buy a cell phone, but it's not the most expensive, most expensive is also took 17,500 to into the net, which means that he in order to be able to use this phone, spent a total of 34,500. 93 34,500 how rich it is.
But in subsequent years, used the phone knows, except in smaller, stand long, and some lace cottage features above and make a fuss, but nothing revolutionary features appeared. Mobile Basic is price, are making phones in China, Shenzhen huaqiang North Street-made mobile phones, the phone has been almost, both function and quality, nothing essentially different. This time I bought the phone selection criteria is who who buy cheaper. Many mobile phone manufacturers have switched to close, more industry-leading companies, and even said to sell the Terminal not to enter this field, because we think that mobile phones have nothing to play for, except for spell spell cost price, it's hard to make money.
Until the advent of Apple's Smartphone, jobs were suddenly shines by people all over the world, Steve was a true genius, so that everyone was surprised to find cell phones that play, also can provide so much functionality. Intelligent machine promotes the development of the mobile Internet, mobile Internet really started after that, due to the development of the mobile Internet, the original wireless communication network is behind, since the original wireless communication networks primarily for voice service, or to phone, data and Internet capabilities are weak. This time it is necessary to upgrade your wireless network, or your cell phone into a brick. Wireless network development, detailed in our network coverage in the back.
To be honest, your cell phone is easy to get a brick, because it involves many aspects, problems with any link, your phone will turn into bricks, not surprisingly, that's just a fact.
Thanks to Terminal promotes the development of the mobile Internet, mobile Internet development and forcing wireless network to upgrade to support higher bandwidth, higher rates, forcing wireless networks continue to develop. Communication network development and promotes the development of the mobile Internet, provide more and better services, and Terminal became more powerful, and mutual development promote a virtuous circle, momentum is promising a bright future.
But for now, the development of intelligent machines seems to have encountered the problem of function like before, had nothing revolutionary features appeared, as the technology matures, estimate subsequent homogeneity will become more and more serious, cabbage at the machine should come soon.
Said we talk about the history of terminal network
This is the focus that we are discussing today, after all, relative to the networks, terminals more simple and easier to understand, and you use, does not require too much explanation.
First generation wireless communications network, which is Motorola's mobile phone, 70, turned out it was very bright and very amazing. Because it is too early in our country estimated network size is very small, Zhejiang TV interview that in addition to the above mentioned man spent 34,500 93 years experience, it is estimated that many people use, including the author, I just heard not seen. But I can certainly of told members, this network except can call outside what also dry can't, cannot sent SMS, and call of effect also not I to, noise big, most situation listening to not clear, because easy by interference Ah; many place didn't signal, base station less AH; and maybe you whole high frequency radio in near, also can stole heard he call of content, because cannot encryption, confidentiality poor Ah. This is the first generation of old gadgets, novelty is an epoch-making product, but it really isn't, 34,500 flowers is absolutely worth it.
Later, second-generation GSM began in our country's rapid popularity of digital communication networks, GSM is the 1990 Europeans out of the second generation of digital communication standards, this is different from analog communications network before, this is the true significance of advanced communications network, very advanced. Many of us first is the contact and the use of mobile communication systems.
And same period corresponds to of Americans make out of standard is CDMA, this is 2G times of communications standard, at of China Unicom using of is CDMA standard, and mobile construction of is GSM network, due to GSM standard more has open and launched more early, in international Shang using of national more, so GSM standard actually to than CDMA using range big, this is at why Unicom ganbuguo mobile of a reasons.
2G appears after the construction of 3G network, smart phones, mobile Internet development requirement for wireless communication networks, must provide faster and wider data business, which leads to why wireless communication networks need to be constantly upgraded, the reason for the continuous upgrading.
Here we also sympathize with operators, was also weighed down by these technologies, constant upgrades, planned investments once benefited more than 10 years or decades, but due to technical upgrading, need to upgrade network you just built a few years. We look after the introduction of GSM, followed by GPRS\EDGE, to the back of the 3G4G, constantly upgrading.
And the 3G technology also involves different world standards (CDMA2000,WCDMA,TDS-CDMA), operators will not be easy, in order to build 3G, you need to build 3 different sets of standard network, equivalent to 3 times times investment money to operate the 3G network. Of course because of the WCDMA standards at the global level to promote good early and open, on the development of first-mover advantage, the other 2 standard will eventually decline, operators in the CDMA2000 network construction on the two 3G and TDS-CDMA inputs almost Boondoggle, super low cost-benefit ratio. Said the estimated telecommunications and mobile cry Halo in the toilet, you can send a few more bonuses, results to equipment suppliers, standards-friendly.
Later 4G although it has been unified, avoid the redundant investment, but also both TDD and FDD mode, FDD-LTE is the mainstream of global 4G standards TDD-LTE for hotspot network in densely populated areas. Different from 3G, cannot be regarded separately as 2 standard, both TDD and FDD 4G system is actually has advantages, each has strengths, can be considered to address the different programmes.
2013 issued in China by the end of the TDD 4G licence required and formally start into the 4G era.
Unfortunately, 4G built not long before, on the lot estimate also could not use, no experience 4G how soon, 5G of concept called zhentianxiang, estimates that the Grizzly is the operator. Investment and construction of 4G just finished, you start calling 5 g, I 4G investment gains have not seen a penny, I carriers are not so white for your device work, and earn some money to buy all the equipment, I have a p. Actual equipment business is not easy, but this is not our topic today, posted after this discussion.
Well, Terminal and network development of finished, estimated all of us have a general understanding of development of communication, but don't worry, we still have to talk about the technical aspects, because any technical discussions would clear me this topic, would be unable to come to the conclusion of this article. Why do I say "4G there is no tomorrow."
Actually we use current communications technology, whether it be computers, chips, optical transmission, wireless modulation and coding, Moore, and these new words, while bright professional enough, but the rationale behind the use of these technologies is the last century of the 560 theory. Although developed for so many years, but has not broken through these basic theories, just in the optimization of the underlying theory. In other words, these product and technology now, with 560 products are essentially no different from the last century, but has made huge advances in technology, smaller, faster and more refined than the original. Just like 100 years ago, Marathon, while we wear shoes better, roads as smooth as the athletes run faster than ever before, but the people running essentially unchanged.
Starting from analog communication, wireless communication to transmit signals through the wireless carrier based on the signals sent and received, this is wireless communication, whether data or voice, is so transferred, the nature has not changed for decades. To make it easier to understand, we can do a simple analogy, a wireless carrier could be seen as one lane on the highway, the cars ran on the lane can be seen as we need to send and receive information.
For more information faster to transfer (bandwidth), is bound to increase the number of cars running on the lane (improve the efficiency of the carrier), and also increase the number of lanes (increasing the number of carriers). These existing wireless communications, there are technical means and have been implemented, similar to FDD/TDD/OFDM these terms just to means of adding lanes for more vehicles, interested students can have a specific in-depth research.
But this method work?
Driveway vehicle can increase indefinitely, when lanes are crammed with cars, when roads into parking lots, can also increase the number of cars, please? Is clearly not.
So lane can you increase indefinitely? If land allowed appears to be infinitely widening the road, fix a bi-directional 100-lane roads is not impossible. But in real life land resources are limited, this waste of resources for road building. Then add layer can better increase lane? A layer of two-tier, three tier, the elevated subway in the city, adding another layer and, theoretically, could increase the number of lanes 1 time without increasing the land area, it seems to be a good measure.
But there is a difference, lane but in a different physical location or altitude, there will be no interference with each other, that is as long as the size is big enough height high enough, you can theoretically unlimited number of lanes, build infinitely wide road. But the radio resources are limited, similar to radio waves of different frequencies in different lanes, but due to the influence of radio wave propagation characteristics, is a range of radio frequencies used for wireless communications, that is to say the total number of lanes is restricted, is not unlimited. Since it is restricted, then the width is limited, cannot increase the transmission rate, which is currently under the rationale of our lanes cannot increase indefinitely.
So in order to be able to run more cars, people thought a lot of ways, such as coding, OFDM, TDD/FDD and air classification, these very well and really improved a lot, but not essentially solved the problem. Similar to the highway, the ground was wide enough, to adding lanes to do, can only increase the level, if you need to continue adding lanes plus a layer, the current increase rate of wireless communication in a manner similar to this. No way, because there are no breakthroughs in basic theory, and optimization of all the improvements, not change, only tinkering with essentially no qualitative leaps, either 3G, 4G or 5G.
But in real life we don't see 2, 3 layers of freeway, could see little of the viaduct are in the urban area, and is the heart of the city, this is why? I believe most people can understand this truth, the reason is cost, overhead or underground transportation, the cost is too high, ordinary roads increase traffic capacity would only be added lanes.
At this point, I believe that most people understand, known as 3G, 4G, 5G, that is by continually increasing the number of carriers to increase bandwidth, and in order to increase the number of carriers, pay the increasingly high cost of technical difficulty also increases exponentially, devices are more complex and require the integration of reliability and higher.
But this has a marginal effect, when you reach a certain level, such an increase does not make sense, because input and not worth it. This is the reason why in reality we didn't see the multiple road.
Some say it doesn't matter, but implementation is done by the manufacturer, I'm just using complex complexity I don't care, as long as I use on the line, Yes. Here a hypothetical, if I was a real estate developer, if there is no story and technical limitations, I took a 100-story building sold to you, would you?
Due to high building volume rate, estimated the price cheaper than houses in the surrounding. But you certainly don't have to, why? Construction safety theory because at the moment we have no big changes before, home lifestyle or a traditional case, lived in high floor there will be a lot of problems.
That is why in theory did not break before, and reason for using traditional way will come to an end, there would be stretched to the limit without conditions. Unless there is a breakthrough in theory, otherwise there will be more and more difficult.
Do you remember what we previously said? Your cell phone is easy to turn into stone. As systems become more complex, realization link more and more possibilities of rock your phone is only going to get higher. Believe that we have the experience, we were there when the call signal can be without 3G4G signal, no Internet access.
So I think that trip on the end of the 4G, 5G, particularly operators of the change network, because if we go only to die, no way out. Advise 4G, 5G equipment research and development colleagues was also the change of thinking, because you will soon be out of a job.
Is there any solution to this problem?
Now there are.
First one, essentially, if you want to solve this problem, there must be a breakthrough in theory, such as similar to the quantum communication the quantum entanglement.
These basic theoretical breakthrough will revolutionize the way existing communications, just as cars on the ground run, instead, you can fly in the sky, in the parallel world of multidimensional space shuttle. Essence has changed, then all the questions are not a problem.
560 were found from the last century to the present basic theory, basic theory of nothing new is born, to breakthrough is easier said than done, so the road is short term basic way.
In addition whether there is a better solution, I think I have. Is the analogy with traffic from country lanes to a highway, from bicycles to aircraft and rockets, which is an-dimensional traffic to meet different needs, will not run in the highway runs the ox cart and aircraft will not appear alone on a plane and go carts.
Communication is also similar, there are still mobile, fast-slow, there are broadband and narrowband, different needs at different times in different combinations, different programmes to be realized.
On this subject, and hope to have the opportunity to post devoted to open alone.
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