US mobile operator Sprint appears to be eyeing a launch of 5G services based on 2.5GHz spectrum in the second half of 2019.

Earlier today the operator revealed that it has been collaborating with Japanese owner SoftBank Corp. and US chipmaker Qualcomm Inc. (Nasdaq: QCOM) on the development of 2.5GHz-based 5G technologies, and that commercial services and devices could arrive in the market in late 2019.

Sprint Corp. (NYSE: S) already holds 2.5GHz licenses and told reporters at this year's Mobile World Congress in February that it was interested in using the spectrum to provide 5G services. (See Sprint Gets Ready for Massive MIMO, Eyes 2.5GHz for 5G.)

Since then, the 3GPP has approved plans to speed up the development of 5G new radio specifications, meaning the first commercial services could feasibly enter the market in 2019 rather than the previously expected date of 2020. (See 3GPP Approves Plans to Fast Track 5G NR.)

The Sprint announcement comes shortly after rival T-Mobile US Inc. said it would build a nationwide 5G network by 2020 using spectrum in the 600MHz and other frequency bands. (See T-Mobile's 2020 Plan Piles Pressure on Europe's 5G Players, Is T-Mobile's 5G Plan Just a Pipe Dream? and T-Mobile Promises 'Nationwide' 5G in 2020 With New Spectrum.)

AT&T Inc. (NYSE: T) and Verizon Communications Inc. (NYSE: VZ), the country's two biggest mobile operators, are also aiming for early rollouts of 5G technology based on much higher frequency bands, including the 28GHz range that is also the focus of much 5G attention in Japan and South Korea.

Signals travel further in lower spectrum bands than in higher ranges, meaning these airwaves are much better for covering large geographical areas.

The very high bands, by contrast, can deliver much faster services -- simply because more spectrum is available -- but do a relatively poor job on coverage.

That means the cost of building a nationwide US network based on 28GHz spectrum could be as much as $300 billion, compared with about $25 billion for a 600MHz-based system, according to operators and analysts that have spoken with Light Reading. (See The Growing Pains of 5G and T-Mobile 5G Plan Could Drive Capex to Record Highs.)

Sprint's 2.5GHz holdings are perhaps best categorized as "mid-band" frequencies that fall somewhere between the spectrum extremes in terms of their capabilities.

In their statement on the latest 5G collaboration, SoftBank and Sprint flagged interest in using 2.5GHz spectrum for "accelerated wide-scale 5G deployments."



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Despite the focus on very high frequency bands in the US and parts of Asia, operators in Europe are looking at using mid-band 3.5GHz spectrum to provide 5G services.

T-Mobile's 600MHz plans could also give a boost to the low-band 5G scenario, with European telcos now thinking of using 700MHz spectrum to support 5G service offerings, according to Heavy Reading Principal Analyst Gabriel Brown.

But the plethora of 5G frequency bands could impede the development of devices and services that can be used around the world, prompting concern about spectrum fragmentation.

Such fragmentation has already bedeviled the rollout of 4G services, which are delivered over a multitude of spectrum bands in different regions of the world.

News of the SoftBank-led 5G collaboration came on the same day the Japanese operator reported a trebling of its net income for 2016, to 1.43 trillion Japanese yen ($12.6 billion), on flat revenues of JPY8.9 trillion ($78.3 billion).

Profits were boosted by asset sales last year as SoftBank worked on reducing net debts, which currently equal about three times the company's annual earnings (before interest, tax, depreciation and amortization).

 Iain Morris, , News Editor, Light Reading