Systems integrators who specialize in DAS deployments are working overtime to meet demand, and scrambling to find enough qualified RF engineers. “I have guys working 24 hours a day seven days a week. Obviously not one team, but it is not uncommon anymore for us to be on site walks on Saturdays and Sundays,” said Darlene Braunschweig of Tempest Telecom. Braunschweig said Tempest is seeing more demand for DAS from smaller carriers and from tower owners. She added that her company is better able to meet deadlines by assigning different teams to installation and to testing.
“Trying to use the same teams that built the system to complete the testing and close that requirement, we just fall too far behind,” she said. “So we’ve added not only tools but people, performance engineers, in order to support that capability.” Many of Tempest’s engineers complete Anritsu training for DAS testing.
“What’s really critical with building the RF section of a DAS, is you need to have people who are trained in RF, who understand what passive-intermodulation is, they need to understand how to repair connectors properly,” said Thomas Bell, product marketing manager for Anritsu’s PIM Master. “There’s two approaches: one is PIM as you go, as you’re building it, which means that every time I place an antenna I check its location to make sure it’s good, I add more coax to it and test, put groups of antennas together and test and just work from the individual antennas backwards, testing to make sure you have connection. Then when you finally connect it all together, you have a working system. That’s the most thorough method, which I think results in the best overall product. However it’s expensive to do that, to do all of that testing as you go. So the other strategy is I just build it, and then go debug and try to find it. So you can get there with both solutions, and I honestly can’t say which is the best solution, but they’ll both get there, it’s just a question of what your appetite is for how long you’re going to be testing.”
Signals Research tests vendor equipment
Speaking of testing, Signals Research recently completed testing of LTE network equipment in all four major carriers’ networks. The group used Sanjole’s WaveJudge 4900A LTE analyzer and IntelliJudge test platform to test LTE networks in San Francisco and Phoenix.
The researchers confirmed that video is responsible for the vast majority of data traffic, but they also noted that operators are not giving enough consideration to the optimization of other mobile data traffic. “Much has been written and said about the impact of mobile video consumption on overall data traffic growth. We believe that equal consideration should be given to all of the other data traffic that exists in the network,” the authors wrote. “It may account for a modest percentage of total data traffic, but it is consuming a disproportionate amount of network resources. When network resources are used inefficiently to support modest amounts of data traffic (soon to include VoLTE) then there are far fewer resources available to support the bandwidth intensive applications, such as video.”
