Spectrum sharing hot topic at ISART
Test and measurement was a major focus of the International Symposium on Advanced Radio Technologies this week, with federal agencies, industry representatives and academic researchers grappling with the technical issues of how the ability to accurately characterize spectrum propagation and interference will be key to spectrum sharing.
After three days at ISART, I came away with a few broad impressions of the level of complexity that has to be dealt with as well as the crucial role that test and measurement will play in enabling new technologies and services for wireless:
• Spectrum propagation modeling needs a lot of work, both in bands that are currently used and in new bands such as the millimeter wave spectrum being explored for 5G. Design and planning for wireless networks need more realistic, holistic models that account better for real-world environments, and field testing is going to be required to validate that the models can be trusted. Particularly in millimeter wave, where reflections, lack of penetration and shadowing are going to be key considerations for system design, there are a lot of tricky factors that will need some good insight into how that spectrum propagates.
• Models are great, but no model is perfect – and arguments over competing models are a huge sticking point when it comes to spectrum sharing. Increased computing power has done a great deal to make modeling faster and hopefully that trend will continue.
• This industry has some great minds working on these issues, and more flexibility is going to be required as the spectrum crunch continues. While CTIA President and CEO Meredith Attwell Baker called for a long-term spectrum plan, she also warned that the need for spectrum will outstrip what is available through auctions, sharing and overall increased efficiency. At the same time, Assistant Commerce Secretary Lawrence Strickling noted that the traditional processes for accessing spectrum – spectrum clearing and auctions making the bands completely, or almost completely, available to licensees – are not a likely path forward. Wireless carriers and vendors may not like the complexity that comes with spectrum sharing, but they’re going to have to deal with it, and they’re going to rely heavily on simulations and field testing to make sure that spectrum sharing works.
You can take a look at the presentations from the conference, including talks from Google on its spectrum access system, Qualcomm on LTE-U coexistence testing with Wi-Fi, Virginia Tech, representatives from the Army and Navy, and more on the ISART agenda page here.
In other test and measurement news this week:
• Anite reported that China Telecom has chosen its SAS test solution for interoperability and device performance, including throughput, as part of its LTE device acceptance testing. China Telecom already uses Anite’s conformance testing toolset as its platform for conformance testing.
• Anritsu launched new universal USB power sensors to detect signals between 10 GHz and 18 GHz for the lab, as well as manufacturing and field environments. The sensors can make modulated power measurements on signals that include wideband CDMA, LTE and wireless LAN as well as GSM, WiMAX and TD-SCDMA.
• Keysight Technologies added high-performance spectrum analysis capability to its PNA and PNA-X microwave vector network analyzers with an eye toward reducing test times without needing standalone spectrum or signal analyzers. It said the integration of a spectrum analyzer to a VNA is an industry first that enables engineers to both perform spurious measurements quickly and do “simultaneous spectrum measurements on all test ports.”
“The ability to make high-performance spectrum and network measurements in one instrument enables unparalleled insight into the device under test,” said Steven Scheppelmann, PNA marketing manager for Keysight’s component test division. “By replacing a switch matrix and standalone spectrum analyzer, this innovation also addresses the increasingly important need to reduce the size of component-characterization test systems.”
Keysight also this week announced a new FPGA processing card for speeding up measurements for envelope tracking and digital predistortion in testing power amplifiers.
