Chapter 1044 A new network form?
For technicians who can participate in the Air Police 2000 project, they may feel numb when faced with a lot of information at first, but now, Chang Haonan has identified the types of data that need to be processed. Divided into two major categories, naturally someone quickly figured out the joints:
“Mr. Chang, for the first category you mentioned, time-sensitive data is needed. Perhaps it can be done in the Ethernet of the communication subsystem. The network transport layer uses the UDP protocol to transfer as much information as possible as quickly as possible. As for the second category, I think it is enough to make certain improvements on the basis of the TCP protocol so that it can adapt to the mixed network medium of wired and wireless. "< br>
This proposal quickly received some favorable feedback:
“I remember that a few years ago, some scholars proposed to set up a small relay station between wired and wireless transmission. The function is just Simply copy the packets in both directions between connections, so that a transmission timeout on the first connection from the sender to the relay causes the sender to slow down data transmission, while a transmission timeout on the second connection from the relay to the receiver If the timeout occurs, the resend will be accelerated”
"..."
However, some people have raised objections:
"But the UDP protocol is not reliable enough in principle. Is it really suitable for transmitting military information?"
"But apart from that, there seems to be no better choice..."
"..."
For a time, the entire conference room fell into a fierce debate, and no one could convince the other group of people in a short time.
However, Chang Haonan did not join in immediately. Instead, he returned to his position and took a leisurely sip of water——
In his current position, although he is not an air police officer The person in charge of the 2000 project, but as long as he makes a statement, there is a high probability that it will become the final decision.
After all, the two chief engineers, Guo Lin and Liang Shaoxiu, have a close relationship with him.
So, he is now gradually inclined to give some guidance, but not to express opinions immediately.
At least give others room to fully communicate.
However, before Chang Haonan could speak again, Guo Lin, who had been being a little transparent just now, stood up:
"I think UDP is not a problem, because the early warning machine Regardless of whether they are fighter jets or fighter jets, the transmission layer and control layer of their combat systems are separated. UDP protocol can be used at the transmission layer, and return verification can be used at the application layer to ensure the reliability of the data. "
In any case, Guo Lin is literally the chief designer responsible for the Air Police 2000 airborne equipment.
As a result, the surrounding area became quiet.
Guo Lin looked in the direction of Chang Haonan, and after confirming that the latter had no intention of adding anything, he continued:
"The problem is still with TCP, how to target HF/VHF/UHF communication links , and satellite communication links to optimize the performance of TCP through different network forms. "
"A comrade did mention an idea just now. I'm sorry that I didn't notice who it was, but I guess it's not him. Our Electronic Technology Group..."
At this point, there was a slight smile in his tone;
"Because the communication method you mentioned does not actually comply with TCP. Semantics, so it will be very complicated to implement at the engineering level..."
On the other side of the conference room, someone showed a slightly embarrassed expression.
He is indeed an engineer from the Haofei Group. He is not from the communications field. He just suddenly remembered a paper he had seen in the past and chose to speak out.
It turned out to be a bit of a joke.
Fortunately, this is something outside the professional field, so no one cares too much.
Since Guo Lin’s words had brought an end to the discussion, Chang Haonan no longer remained silent, but stood up again and returned to the front of the conference room:
"Actually... everyone has overestimated the difficulty of optimizing the TCP protocol."
He tapped the blackboard lightly and said:
"The relay platform we use, of course, does not refer to The comrade just mentioned the relay between wired and wireless, but the relay in the wireless communication process. In the future, it will be a satellite, but in the current test, it is a stratospheric airship. This platform has passed the performance test. "< br>
“Because of the use of brand-new network coding technology, extremely low bit error rates and delays can be guaranteed even in complex electromagnetic environments. Although it is not yet said to be at the same level as wired networks, it is at least better than in the past. ...Or the existing wireless transmission technology is much more reliable.”
These words confused many people present——
Wasn't your old self the first person to say that the TCP protocol should be improved?
Why are you now saying that we overestimated the difficulty of this matter?
Faced with more than a dozen confused faces, Chang Haonan did not show off, but erased the small triangles and circles he had just drawn on one side of the blackboard and filled in a new diagram.
While drawing, he explained:
“Actually, the idea of setting up a relay point between wired and wireless transmission cannot be considered problematic.”
"Huh?"
Guo Lin immediately couldn't hold himself tight.
He just swore to criticize others. If he found out that he was wrong in the end, all the boomerangs would be pierced in his head.
Chang Haonan deliberately paused for a while, and then turned around and added:
“Of course, Mr. Guo’s subsequent criticism is also correct.”
"Huh——"
Guo Lin finally breathed a sigh of relief, and his blood pressure, which almost exploded, also dropped.
“We can add a detection agent to detect and cache TCP data segments sent to removable hosts, and return acknowledgment information.”
Chang Haonan represents wired data segments A reverse dotted arrow is drawn on the part of When confirming, it means that there is a problem with the wired part, and the original data segment needs to be discarded and resent..." "And if the confirmation is returned that everything is normal, but there is still a transmission failure in the entire transmission, it means that the problem lies in the wireless part. …”
“The specific implementation strategy still needs some testing, but because the bit error rate is not high, the path MTU minus the header size of TCP and IP can generally obtain the best performance...”
"..."
The improvement plan proposed by Chang Haonan is not complicated. It will only take a few weeks or one to two months at most to complete, and it is basically software or some small-sized hardware level. The measures can be easily operated in the cabin and will not even affect the final assembly progress of the Air Police 2000 prototype.
As for the audience below, they looked at each other in confusion.
Although no one said it directly, the expressions on their faces clearly showed the same meaning -
Is this the end?
When Guo Lin first discovered this problem, including when Chang Haonan took them into this lounge just now, the solemn atmosphere made people think that the entire Air Police 2000 project would be postponed because of this.
Is this the result?
Chang Haonan naturally saw the psychology of everyone.
"So far, we have only solved the optimization of the TCP protocol for several traditional communication links, so it is indeed relatively simple."
He took a step forward and said unhurriedly:
"But don't forget, the information command system I just talked about..."
At this time, the doubts on everyone's faces not only did not decrease, but also increased.
After a while, someone tentatively asked:
"But... doesn't that command system also rely on these types of communication links to issue orders?"
"Not exactly."
Chang Haonan waved his hand:
“All the situations we are currently imagining have preset a center for the entire communication system, which is the early warning aircraft. Of course, it may also be a higher-level command headquarters, for the same reason.”
“But In reality, for example, when troops are rapidly deploying and advancing on the battlefield, the communication center cannot move forward simultaneously with the front-line units due to safety or tactical considerations. In this case, the mobile network with a center cannot meet the needs, and What is needed is a new communication link that can quickly, temporarily, and automatically form a network..."
"Distributed communication?"
Soon, someone threw out the keyword.
“Yes.”
Chang Haonan affirmed:
“Thanks to our latest development of relay technology, wireless communication can also be carried out with low loss and Low-latency multi-hop forwarding, so we can take advantage of this and design a new form of communication network.”
When he said "brand new", there were several obvious breathing sounds coming from below.
No one thought that Mr. Chang was actually planning to play such a big game——
So far, the cornerstones of human modern communication technology, such as network structure and communication protocols, are still developed by developed countries. Constructed.
For the sake of standardization and globalization, China has also chosen to adopt most of its contents.
After all, it is a process of making wheels.
It will probably take another few years to challenge the first-mover countries in this regard.
But obviously, Chang Haonan no longer wants to wait.
Therefore, he is ready to first test the waters in the military field that does not pursue global integration.
Chang Haonan gave everyone a few seconds to recover from the shock.
Then, on to the real meat and potatoes:
"In addition to multi-hop forwarding, this network should also have the following characteristics."
"First, there is no center. All nodes have equal status in the system. It is a peer-to-peer network. Any Nodes can join and leave the network at any time, and even failure will not affect the operation of the entire network. "The second is self-organization, and the deployment or deployment of the network does not need to rely on any preset network facilities. By coordinating their respective behaviors through layered protocols and distributed algorithms, nodes can quickly and automatically form an independent network after they are powered on. "
"The third is dynamic topology. For the sake of application background, the network. Nodes will move anywhere at any time, and may be powered on and off at any time, which will cause changes in the network topology, but the network itself must ensure smooth operation. "
"So, such a communication network is not only about the architecture. It is significantly different from ordinary cellular mobile communication networks and fixed communication networks in terms of network organization and communication protocols, and corresponding adaptation of communication protocols is required. ”
He returned to his seat, took a deep breath, and looked around:
"This is the most important and most difficult task in the next TCP optimization!"
(End of this chapter)