The idea of using multiple network layers--macro and small-cell--to improve user data rates and network spectral efficiency has been bantered about for some time, but AT&T (NYSE:T) appears to be the first operator to move ahead.
As pointed out by Sidecut Reports, AT&T is proposing to build some 80 new small-antenna tower sites on top of utility poles across downtown Palo Alto, Calif., in a bid to bolster voice and data capacity in areas that experience heavy data traffic. AT&T is calling the initiative Distributed Antenna System (DAS), which is the lingo used for in-building wireless communications.
AT&T spokesman Lane Kassleman told the Palo Alto Patch earlier this year that downtown Palo Alto "has one of the highest concentrations of smartphone users in the nation--most of whom are surfing the Web, downloading music, streaming data and making calls. To help bolster capacity, AT&T is proposing DAS throughout downtown Palo Alto."
The move is similar to AT&T's tests of Wi-Fi hotzones that the operator expanded into more cities this past summer as a way to ease data capacity. DAS looks to be another tool for easing data traffic. I'd like to see the city approve the plan. While small cells represent a way to offer subscribers better capacity and higher data speeds, they also come with interference and network architecture issues that need to be overcome.
Namely, how do operators manage all of these small cells within the macrocell network? Small cells underlying bigger cells creates interference and hand-off issues because devices will switch back and forth based on where the stronger signal is. Certainly elements of self organizing networks (SON) will have to play a role. Other sticky issues are deployment and backhaul costs. If operators are to deploy many small cells in a given area, deploying them and backhauling their traffic should not become monumental tasks. These will be issues that I'd like to see AT&T tackle.--Lynnette