Recent field trials have shown important results for CoMP and eICIC. Mobile Experts has been tracking these technologies for years, and frankly, I was getting tired of hearing about the theoretical gains of CoMP or simulated results. Recently in Japan, Softbank and Airspan conducted a trial, and they've recently released some hard data on how these features work. This was a solid field trial, testing performance under heavily loaded conditions and testing of multiple scenarios.
In short, these features help where operators need it. Out on the street, where macro coverage is good, the benefit of CoMP using Joint Transmission is nominal: at less than 5% or so. Aggregate capacity increased by 7% when CoMP was switched on by itself. Combining CoMP and eICIC increased aggregate capacity by more than 20% compared with the baseline HetNet.
That's all fine, but these LTE-Advanced features really shine at the cell edge. CoMP alone provided more than 130% boost to throughput at the cell edge, and CoMP/eICIC boosted the downlink by more than 250%.
Source: Airspan and Softbank field trial data
We've done cost/benefit analysis to calculate whether it's worthwhile to invest in CoMP/eICIC based on the capacity gain. But let's look beyond the numbers for a moment; mobile operators often focus on boosting the peak datarates with MIMO and Carrier Aggregation. These techniques offer an opportunity to smooth out the experience of the user. Users that get 50 Mbps in some locations and 50 kbps in other locations are not happy users. But users that consistently get 1-5 Mbps everywhere are receiving a predictable service that they can trust.
We believe that predictable and reliable are the words that will differentiate mobile services from Wi-Fi and prevent major erosion of ARPU in the age of Wi-Fi First services. Mobile operators need to invest in CoMP and eICIC as a way to improve their consistency of coverage. We expect to see a lot of innovation around split-baseband architectures and CoMP implementation over the next four years.
Joe Madden is Principal Analyst at Mobile Experts LLC. Mobile Experts is a network of market and technology experts that provide market analysis on the mobile infrastructure and mobile handset markets. He provides market forecasts for handset, DAS, small cell, and base station markets, with in-depth research down to the nitty gritty details of frequency bands and power levels. Mr. Madden graduated, cum laude, from UCLA in 1989 and is a Silicon Valley veteran. He has survived IPOs, LBOs, divestitures, acquistions, and mergers during his 24 years in mobile communications.