June 12, 2013, 7:02 PM — On the roof of a medical building in San Francisco, Sprint Nextel has a cell site that's far above the cramped canyons of the city's streets, but despite the wide-open views, space is limited.
Sprint shares the roof with other mobile operators also taking advantage of its high vantage point, and each needs backup power supplies in addition to the large, raised cabinets that contain their cellular base stations. That's one reason Sprint is now putting all its services into one box and deploying smaller radios that can sit next to its antennas at this site, as well as at other buildings and cell towers across the country.
The project, called Network Vision, will also boost the range of Sprint's cells and make it easier to add more frequencies and network types in the future, the company says. That's important to the nation's fourth-largest mobile operator, which will still be using three different cellular technologies even after it shuts down its aging Nextel system at the end of this month.
At the cell site that Sprint showed off to reporters on Tuesday, one of about 2,000 in the San Francisco Bay Area, the company has its old equipment alongside the new gear. It consists of two cabinets, each the size of a large refrigerator, just for the carrier's 3G CDMA voice and data service. Alongside them are another large cabinet for wired telecom connections and one for backup batteries in case of power failure.
Next to those four boxes is the Network Vision gear, consisting of a smaller cabinet and battery pack. That's where Sprint is running its LTE service on frequencies set aside for it in the 1.9GHz band. The new gear is also much more compact: The work of each of the old cabinets can be done with one rack module, called a "digital unit," in the new box. Alongside those are units for Sprint's LTE service on the same band, plus modules for improved 3G voice service on 800MHz, the band that the company is getting back by closing down Nextel.
The same cabinet can hold future units for LTE in the 800MHz band, as well as gear for the 2.5GHz band. Clearwire, which currently provides Sprint with its WiMax network, will use 2.5GHz to deploy its own LTE network that will complement Sprint's. Through a hosting deal, it will deploy that gear in the Network Vision cabinets.
With old technology, each of those services would have required its own cabinet and batteries in every location where Sprint needed them, said Joe Meyer, Sprint's vice president of network service management.