AT&T may be ready to begin its small cell push

Nokia Siemens’ conceptualization of a HetNet with macro, micro and pico cells represented by different colors

AT&T(s t) has started sending out small cell feelers to its vendors, according to Light Reading, which could be the first sign that AT&T is preparing to make big changes in the fundamental topology of its networks. Citing unnamed sources, Light Reading said AT&T has put out a request for information (RFI) to mobile infrastructure vendors, indicating it is looking to procure as many as 100,000 pint-sized base stations.

AT&T has already said it plans to start trials of small cells this year, but 100,000 units is more than just a trial. That amount of new cells is big first step toward creating the heterogeneous network, or HetNet, of the future, in which a dense layer of small high-capacity cells lives under the macro-cellular umbrella. According to the Light Reading report, AT&T is looking to go multi-mode, deploying HSPA, LTE and Wi-Fi nodes.

Of course, this doesn’t mean AT&T is going to start plopping down small cells tomorrow at every street corner. The RFI is likely only dictating what AT&T envisions the eventual scope of a full-scale small cell roll out would be. It still has to trial the technology to see if it works, and so far many operators have been a bit skeptical about the benefits small cells will bring. Verizon(s vz)(s vod), for instance, is planning its own small cell rollout, but it’s being very conservative about the amount of capacity they will add to its network.

AT&T, despite being behind Verizon on its current LTE rollout, is actually quite progressive when it comes to exploring cutting edge wireless technologies. It’s adopted Intucell’s self-optimizing network (SON) technology into its LTE and HSPA networks. SON essentially breathes life into what would normally be a bunch of static cells, allowing them to expand and contract to meet the changing capacity demands of the network.

If AT&T can get small cells to work it could achieve capacity gains that would far overshadow any gains from buying new spectrum. Considering AT&T is lobbying hard for new airwaves and warning of a looming spectrum crisis, it may not be too keen about advertising its small cell plans. But those plans seem to be shaping up nonetheless.

Small cells also might become a new point of contention between the carriers, as it will increase the mobile industry’s dependence on AT&T and Verizon. The big issue with small cells is backhaul. Hooking big macro cells to fiber links is already a chore for operators, so imagine the difficulty of backhauling millions of small cells.

Sprint(s s), which has big small cell plans of its own, is warning that the big incumbent wireline and cable operators could crush smaller mobile operators by overcharging them for, or flat-out denying them, backhaul links. FierceWireless reported that Sprint is lobbying the FCC to impose conditions on Verizon’s acquisition of the cable operators’ Advanced Wireless Services spectrum since the deal would create what in effect is a wireline trust able to dictate backhaul pricing.

According to an FCC filing, Sprint said wireline operators are already charging the same rates for microcell backhaul connections as they charge to connect a macro cell tower. Such policies would have an enormous impact on Sprint’s future plans since any HetNet would require many times more small cells than macrocells.