Sprint Corp. (NYSE: S) wants to shrink WiMax base stations even further so that they can be used to enhance data transfer speed and capacity in the home, Unstrung has learnt.

Sprint has already revealed some of its plans to ensure decent WiMax coverage inside larger buildings with picocell WiMax radios for campuses, offices, shopping malls, and conference centers with picocells. The Reston, Va., operator also has an RFP out for what it calls "Low Cost Internet Base Stations" but most others in the industry call home base stations or "femtocells." (See Sprint Taking WiMax Indoors.)

A home base station, or femtocell, is a low-cost, low-power 3G cellular radio system that users can put in their dwellings to boost bandwidth and coverage and enable new applications such as fixed/mobile convergence (FMC) in the home. Such mini-base stations have become more interesting to vendors as operators have started to take the devices more seriously, both as an alternative to WiFi hotspots or as a complementary technology.

Sprint has already made it clear that it anticipates that in-building coverage will be an important aspect of its WiMax rollout. "Femtocells are on our radar," says a spokesman for the operator.

The spokesperson, however, wouldn't be drawn on any specifics about particular RFPs. "As a matter of policy we don't comment on RFPs," he says.

Sprint is said to be looking for several hundred thousand of these mini-base stations along with smaller -- but still significant -- numbers of picocell-scale equipment for its WiMax deployment, which is at a testing phase right now and due to go live in many major cities in the U.S. in 2008. CDMA and EV-DO support could also be part of the specifications for these appliances.

The problem for vendors wishing to compete will be pulling together these disparate networking technologies. Indoor wireless specialist RadioFrame Networks Inc. has been upfront in its plans to bring a WiMax home base station to market. The company has already worked with Nextel on indoor systems and must be considered a strong contender for any new contracts. (See Femtocells Gear Up for 3GSM.)

Meanwhile Unstrung Insider analyst Gabriel Brown considers AirWalk Communications Inc. , Airvana Inc. , and Samsung Corp. to all be in the running since the three vendors are established in the CDMA business. Samsung also has the WiMax chops and experience, especially now that it has been involved in early deployments in South Korea.

Silicon could be key in enabling a multi-radio mini-base station. Qualcomm Inc. (Nasdaq: QCOM) has already started to express an interest in developing chips for this type of application. Major players such as Texas Instruments Inc. (NYSE: TXN), as well as smaller companies like Picochip , are already working on dedicated femtocell chipsets. Meanwhile, RadioFrame is extending its own OmniFrame silicon to support WiMax. (See Qualcomm's Home Invasion.)

Insider analyst Brown, author of the recent "3G Home Base Stations: Femto Cells & FMC for the Masses" report, says that no matter what happens with Sprint's WiMax-related work, femtocells are one of the new hot technologies in the world of wireless. (See Base Stations Come Home.)

"A major operator will roll out a femtocell deployment this year," says Brown. He predicts that either a CDMA operator in the U.S. or a European operator that has a serious GSM footprint but few 3G networks will be first. [Ed note: No names, no packdrill, eh?]

— Dan Jones, Site Editor, Unstrung