Rebirth: Starting from Lighting Up the Tech Tree

Chapter 42 Delivery

On August 8th, the final version of the third milestone of the Sky Dome project entered the integration testing phase.

The full module integration testing was the most dangerous part of the entire project—four independently developed functional modules were running simultaneously on the same embedded board for the first time, and even a minor problem in any module could trigger a chain reaction. Before the integration testing began, Zuo Cheng conducted a three-day pre-test, running each module individually to confirm there were no hidden dangers before ordering the merging.

Everyone was in the office on the day of the merger.

Fang Ze sat in front of the development board, his fingers hovering over the keyboard, the screen displaying the startup logs of the four modules. Zuo Cheng stood behind him, with Chen Hao and Zhang Lei on either side.

"Begin," Zuo Cheng said.

Fang Ze pressed the Enter key.

The logs for all four modules begin scrolling simultaneously. The signal receiving module completes initialization first, followed by the demodulation module, then the channel estimation module loads its prediction model, and the beam management interface enters standby mode.

Everything was normal for the first thirty seconds.

At the forty-first second, a red warning message appeared on the screen.

"The beam management interface reported a timeout." Fang Ze's voice tightened as his fingers flew across the keyboard, bringing up the detailed logs. "The predicted data packet output by the channel estimation module has a format mismatch in one field compared to the expected format of the beam management interface—it's off by one byte for alignment."

One byte.

The entire system stalled due to a single byte alignment difference.

"It's my fault," Zuo Cheng immediately admitted. "I revised the output structure of the channel estimation module last week, adding a status flag. The total length of the structure changed, but I forgot to update the interface documentation. Fang Ze's beam management interface is written according to the old documentation."

"Should we modify the interface documentation or the structure?" Fang Ze asked.

"Modify the structure. Compress the status flag from four bytes to one byte, implement it using a bit field, and keep the total structure length unchanged." Zuo Cheng had already mentally reviewed the solution. "Give me ten minutes."

He sat down at his workstation, changed seven lines of code, recompiled, and replaced the module.

Second joint commissioning.

This time it ran for four minutes without any errors. Fang Ze began to increase the load—simulating the entire process of a satellite passing over the ground terminal, from signal acquisition to stable tracking to switching to the next satellite, a total of twelve minutes.

Twelve minutes later, all indicators on the screen turned green.

"Peak CPU utilization is 68%, peak memory usage is 283 MB, maximum channel prediction latency is 1.7 milliseconds, and beam switching success rate is 100%." ​​Fang Ze read out the data one by one, his voice becoming more and more steady.

Zhang Lei let out a soft sigh of relief.

"Don't relax yet," Zuo Cheng said. "Run a 72-hour stability test."

Seventy-two hours. The same duration as when we conducted base station testing at Blue Bay Communications.

For the next three days, someone would be on duty in the office 24 hours a day. Zuo Cheng made up a schedule—he would take the first two night shifts, Fang Ze would take the third night shift, and Chen Hao and Zhang Lei would take turns keeping watch during the day.

The first night shift went smoothly. Zuo Cheng leaned back in his chair, half-asleep, staring at the monitor screen; the system was running like a precise clock.

At 3 a.m. on the second night shift, the system experienced a memory fluctuation—the utilization rate of the second-level circular memory pool suddenly jumped from 40% to 75%, lasting for about 20 seconds before automatically dropping back down.

Zuo Cheng checked the logs and found that the simulation test script switched to an extreme scenario at that time—heavy rain combined with multi-satellite switching. The channel estimation module instantly generated a large amount of temporary computation cache. The second stage of the three-level memory architecture successfully absorbed this peak, without overflowing to the third stage, and the system was not affected in any way.

He noted the event in the test log, marking it as "expected behavior, no fix required".

The third night shift ended at 8:00 AM on August 11th.

Fang Ze stood up from his chair, stretched, and turned to Zuo Cheng, saying two words.

"Passed."

Seventy-two hours, zero crashes, zero anomalies, and all performance metrics met the standards.

Looking at the smooth system operation curve on the screen, Zuo Cheng felt a familiar feeling welling up inside him—just like when the Tianqiong joint review was passed, not ecstatic, but a heavy sense of relief.

The following week was for finalizing the documentation. Technical documents, test reports, user manuals, source code audit reports—Han Lu compiled a list of fourteen documents, each with its own format template and content requirements.

Zuo Cheng assigned the documentation work to everyone: Chen Hao wrote the signal reception and demodulation section, Fang Ze wrote the embedded platform and performance optimization section, Zhang Lei compiled the test reports, and Zuo Cheng himself wrote the core algorithm document for channel estimation and the overall architecture description. Han Lu was responsible for the final formatting and business documents.

On August 15th, the entire set of deliverables was packaged and completed.

Zuo Cheng gave the file list a final check—software source code package, compilation scripts, fourteen technical documents, four test reports, and one user manual. In total, it consisted of over three hundred pages of documents and 120,000 lines of code.

He clicked the submit button.

The ground terminal signal processing module for the second phase of the Sky Dome project has been officially delivered.

There was a few seconds of silence in the office, then Zhang Lei led the applause.

"From signing the contract on April 10th to delivery on August 15th, it was 127 days." Han Lu glanced at the calendar. "The contract period was 120 days, so it exceeded that by seven days, but it's within the flexibility allowed in the contract and won't affect the acceptance."

"When will the final payment arrive?" Liu Wei asked a very practical question.

"Twenty percent will be paid upon final acceptance, and the remaining ten percent will be paid after the three-month technical support period," Han Lu replied. "If the acceptance goes smoothly, the twenty percent payment should arrive in early September."

Zuo Cheng did not participate in the discussion of the final payment. He stood by the window, looking down at the cement road below, which was baked white by the August sun.

Four months. 402 completed a million-dollar commercial project in four months.

This is not just a matter of money. It means that 402 has been officially accepted by Blue Bay Communications' supply chain system—with the delivery record of the Sky Dome project, future participation in Blue Bay Communications' bidding will only require a single sentence for qualification review.

The light curtain appeared quietly.

[Main Quest - Skywards Delivery: Completed!]

[Project Evaluation: Pending Acceptance and Confirmation]

[Task Reward: To be issued upon verification]

Zuo Cheng turned off the control panel. The acceptance results were still pending, but he was already thinking about the next step.

My phone vibrated twice.

The first message was from Yu Ying: "Brother, has it been delivered?"

"I've paid it."

"You've worked hard. I'll cook dinner tonight, come over for dinner."

Zuo Cheng smiled and replied with "Okay".

The second message was sent by Han Zhe.

"Zuo Cheng, congratulations in advance on the Sky Dome project. I also want to give you a heads-up—Blue Bay Communications is hosting a technology partner conference next month, inviting core suppliers. 402 is on the invitee list. Chairman Zhou will announce the next phase of the Sky Dome project at the conference. If you're interested, September 10th, Blue Bay Communications headquarters."

Zuo Cheng stared at the message, his finger hovering over the screen for two seconds.

The next phase of the celestial dome.

The outlines of the gray branches on the technology tree appeared in his mind—the branches of communications engineering were already lit, but there were still too many places in the crown waiting to be lit.

"I'll be there," he replied.