It was February of 1994 when we were about to make our second trip to China. This was the China from before the current industrial revolution that has made China a manufacturing powerhouse. It was before cellular phones were available in China, before there was large scale manufacturing in China that had moved from the United States and other countries. It was a China of what seems to be long ago.
We had made a previous trip to China in November 1992 in which we had installed a 3 site LTR analog trunked radio system for the power company in Chengdu, the capital city of Sichuan Province, China. After long negotiations, we returned to China to install a 4th site on the system and to add features to the system such as dispatch networking and follow me roaming using the model CR355 Call Router manufactured by Trident Micro Systems. The existing system consisted of radios manufactured by Uniden Corporation, power amplifiers by PowerWave and site controllers made by Trident Micro Systems. This provided for easy interface of the repeater system to the CR355 since the two items were made by the same company and were designed to work together.
This job involved some considerable challenges just as the first trip to China. Anything that would be required for the job must be carried by us from the US or shipped to China with the equipment. We could not rely on anything being available in China as there was no internet, no phone books, no cell phones and only about 1% of the population has land line phones. There was almost no way to find anything we needed unless our hosts at the power company knew where to find it. Since our business deals with specialized communications equipment that is not readily available from sources that do not specialize in our business, locating anything in China was a dismal failure during our last visit and we did not expect this trip to be any different in that respect. Therefore, we had to anticipate anything and everything that could go wrong so that we could complete the job under any circumstances. Those circumstances managed to present themselves in spades during our 3 week stent in China.
The new features that we were installing required some type of connection between the tower sites. Physical phone lines were few and far between in China. The power company had their own microwave systems that connected their offices together and also connected to their tower sites. This was the perfect solution to our need to connect the site together for the customer.
During the negotiations, we had the power company send us the schematic (wiring diagram) of the microwave channel cards. We had to interface the radios to the microwave system to make the dispatch networking and the follow me roaming functions operate properly, so we wanted to be certain that we fully understood the microwave interface and the input / output levels that were necessary for proper interface. We noticed that with a simple modification of their microwave card that we would be able to significantly simplify our interface to their microwave system. We asked and received permission to make the simple change to their microwave channel cards. At each site, there were 5 channel cards, so we had to bring the parts to make our simple change to each of the 5 cards at the 4 different tower sites. Upon arrival at our project kickoff meeting, they reversed their decision and told us that we would not be allowed to modify the microwave channel cards. This caused us to have to redesign our interface on site using only the extra parts that we brought with us just in case we needed to do something that we did not plan upon nor expected to have to do in China. This caused us considerable grief, nail biting, consternation and worry. Redesigning our microwave interface required modifying 20 cards. Did we bring enough parts to do the job? Did we bring the right parts to do the job? Could we manage to figure out a circuit that would use only the parts that we had on hand? Did we have the time to make the changes based upon our schedule? All of these were good questions for which we did not have an answer until we returned to our hotel room and completed the circuit redesign, inventoried our spare parts and modified one of the CR355 units with the revised interface. We made every attempt to test our new circuits, but we ultimately could not fully test our work until we had the microwave connections to verify that our circuit worked properly.
Now it was time to go to sleep as we had to be up early the next morning. We were heading to the first tower site, the one closest to the power company office in Chengdu. There we installed the Call Router and connected to each of the 5 repeaters. The CR355 part number indicated the basic functionality of the call router. It connected 3 DID (direct inward dialing) circuits with 5 repeaters and 5 DOD (direct outward dialing) circuits. We obtained the 5 DOD microwave connections from the power company that were set up by the power company in the 4 wire E&M signaling mode to make the system operate full duplex with the greatest fidelity & duplex isolation so that the system would perform properly. We then tested our new circuit design with the microwave circuits and we found that it worked fairly well, but one of the resistor values needed to be changed to make the interface more reliable and reduce the possibility of failure. The interface to the 5 repeaters needed to be reconfigured to connect properly to the call router. This necessitated opening up each TNT-100 logic deck and changing the jumpers so that it recognized the proper hardware interface. We also had to log into the configuration screens in the TNT-100 to change the software to operate properly with the CR355. We also had the power company provide us with 3 DID circuits that were a direct connection to the call router from the microwave system. We tested the call router functions multiple times and everything seemed to work well. Once we were convinced that the system was working properly, I changed the speech prompt prom from English to Chinese. That way, the radio system issued all prompts to the radio users in Chinese instead of English.
We headed back to the power company and eventually to the hotel. We had dinner and went back to our rooms where we proceeded to modify the interface for the next site. The next day, we headed to another tower site and proceeded to go through the same procedure, testing all of the DID circuits, the DOD circuits, the interface to the repeaters. We were starting to feel confident that we would get through this job and get everything to work properly in spite of the problems we encountered upon arrival.
The next day, we left to go to Omi Mountain, a tower site that was a full day’s drive from where we were located in Chengdu. We packed our suit cases and loaded the equipment into the cars. This site was at 10,000 feet and it was winter time. We would drive to the 7000 foot level and then take an aerial tram to the site at the top of the mountain. There was a retreat at the top of the mountain and the radio site was at the highest point of the mountain. We proceeded to perform the system upgrades and got everything working just like the other two sites. We then stayed over night at the site and proceeded to head back to Chengdu the next day.
Now it was time to install the new site at the power company building in Chengdu. They had a 10 story building with a tower on top of the building, providing quality coverage within the building and the surrounding city. We removed the equipment from the crates and proceeded to locate the equipment in a room near the top of the building. We installed the antennas, the equipment and the new CR355 Call Router. We attached the equipment to the microwave system, completely tested all the functions and then changed the speech prompt PROM from English to Chinese, just like the other sites.
Now it was the time to perform the final testing of the network. I sat in front of the computer screen attempting to place a call from one site to another, but the system did not respond correctly. I tried hundreds of configuration changes, but to no avail. I worked on this for 3 days, trying to find some reason why the system did not operate properly when everything seemed to work properly at each of the sites that we had set up in the field.
I used the phone to call Trident Micro Systems in the United States to have them assist me in resolving the problem. I spent hours on the phone with them and they claimed that they were unable to duplicate the problem. Since we were about 15 hours ahead of them in time, communicating with the factory had its challenges. Additionally, when they would attempt to call me back, they would get the operator at the power company who did not speak any English, so they would have severe difficulty attempting to call us back whenever it was necessary to give us the results of the tests that they would run on their equipment. I was at the power company from 6AM until 1AM the next morning for 3 days in a row. I was operating on the brink of complete exhaustion, but the will to go on was ingrained into my soul. Nothing was going to prevent me from solving the problem, but thus far, the solution had been elusive for both me and the factory.
It was now the day that we were supposed to leave to go to the airport to catch our plane to return to Hong Kong before returning to the United States. The system was still not working correctly and it was 7AM in the morning in Chengdu. I called the Trident Factory in desperation to find out what was the results of the test that they had run on their equipment. I got Dave on the phone and he reported that they have been completely unable to duplicate the problem in any way, shape or form. They were completely stumped and so was I. We had to leave to go to the airport at 12 noon to stop and eat before heading to the airport to catch our plane. There were only 2 planes per week out of the Chengdu airport to Hong Kong. If we missed this plane, we would have to wait 4 more days to catch the next plane, assuming that we could get space on the plane. My 10th wedding anniversary was about to arrive and if we missed this plane, I would miss my 10th anniversary which would not go over well with the wife. I had to solve the problem and had only about 5 hours left to find it, but I have not been able to resolve it in the past 3 days, nor could the factory resolve it either. So I took a new approach with Dave to attempt to resolve the problem. I asked Dave to look at the version number of the logic board he was using to troubleshoot the problem. He reported the version number and I verified that I had the same version. I then asked him for the version number of the firmware he was using and he was using another software version. He changed his version number to match mine. We still had the problem and he did not have the problem. We then compared the version number and software version of the front end board and both matched. We scratched our heads and proclaimed that there was no way that I could have the problem with every unit that was in the system and he could not duplicate the problem, but we still had the problem.
We lamented that everything was the same between our two units, but his unit would not do the same thing that our unit was doing incorrectly. I then had an inspiration. I asked him if his unit was speaking Chinese. He replied no, his unit was speaking English. I asked him if he had a Chinese speech PROM and he said that he did not have one, but he could make one; however it would take him about 10 minutes. While I was waiting for him to make the Chinese speech PROM to test, I opened up the CR355 at my location and changed the Chinese speech PROM to English. My unit immediately started working correctly! Dave finally came back to the phone with the Chinese speech PROM and inserted it into the unit at his office. It now duplicated the problem the I was having with the units here in China. We had solved the problem and it was only 10AM. We still had two hours before we had to leave for the airport, but we needed to make 3 more English speech PROMS so that the power company personnel could insert the chip into the proper socket in the CR355 Call Router at the other 3 sites until we could get new (working) Chinese speech PROMS sent to the power company at which time they could change out the English for Chinese.
Our problem was not over. We did not have another English speech PROM. We brought only one English PROM because we wanted to be able to test it in English and then switch it to Chinese. We never thoroughly tested the Chinese speech PROM in the United States because we never suspected that it would cause the Call Router to work improperly. To our knowledge, it only controlled the language of the speech prompts. So when we tested it in the United States at our offices, we only tested it enough to determine that it spoke what we thought was Chinese instead of English since we do not speak Chinese. It did speak Chinese, but it caused another portion of the software to work improperly, something that we did not detect at our offices when we tested the system.
We now went to the technical section of the power company and found that they had spare PROMS of the same type. They also had a PROM eraser and had a PROM writer. So we read our English speech PROM with their reader, erased one PROM at a time and wrote to the PROM to create additional English speech PROMS. By the time we had completed this exercise, we had a whole 10 minutes before we had to leave for the airport!
We left the power company with the knowledge that we had determined the cause of the problem and that we had implemented a temporary solution that would await a permanent solution from the Trident factory. We stopped for lunch on the way to the airport celebrating our success in successfully installing the system and making the project work as represented. We just had to be certain that the Trident factory followed through with fixing the Chinese speech PROM and sent the PROM to us so that we could forward them to the power company. After lunch, we headed to the airport, boarded our plane and flew to Hong Kong.
We had planned to spend 2 days in Hong Kong to unwind and have some fun. We had been in China for 2 weeks working 16+ hours per day and we were anxious to relax and see some of the sights. Unfortunately, our timing was not good as Hong Kong was slowly getting over Chinese New Years with almost everything we wanted to do was closed for the new year and would not reopen before we planned to leave. After 2 days of being disappointed at every turn, we boarded our airplane to Los Angeles and arrived at LAX around 10AM during the week.
My wife picked me up at the airport and drove me directly to the office where my car was parked. This was done on purpose to keep me up until nighttime when I planned to go to sleep so that I was operating properly on Los Angeles time. I worked at the office until about 5:15PM at which point I attempted to drive home. At this point, I had been up for over 30 hours and was exhausted. I attempted to drive home and found myself falling asleep in the car while attempting to drive. I turned on the air conditioner blowing cold air in my face, rolled down the windows, continued to slap myself in the face every 30 seconds, squirmed in the seat and tried yelling at the top of my lungs to stay awake. I barely managed to get home without falling asleep at the wheel. I immediately got ready for bed and crawled into a soft and comfy bed.
The next thing I knew, it was 8AM the next morning. I felt fine and went to work at the office. It was a new day in paradise……………………