Verizon Wireless has defended its proposed US$3.9 billion acquisition of a swathe of spectrum from a group of US cable companies – claiming that its new 4G/LTE network would reach capacity as early as next year without the new bandwidth.

In an FCC filing, the US number one said that its current spectrum "will not provide sufficient capacity to meet the growing demand for mobile broadband by 2013 in some areas and by 2015 in many more.”

Verizon is buying spectrum from cable companies Comcast, Time Warner Cable, Bright House Networks and Cox Communications in a bid to relieve congestion in many of its networks – but rivals are attempting to block the deal.

"Our usage projections suggest that traffic on our LTE network will surpass data usage on our EV-DO network in early 2013," added the operator in the filing. "By year-end 2015 our LTE data traffic is projected to be 5 times the peak data traffic ever carried on our 3G EV-DO network. The impact of that growth rate compounds, resulting in a more than 20-fold increase in LTE data traffic from year-end 2011 to year-end 2015."

According to the Wall Street Journal, rival T-Mobile USA said in an FCC filing last month that the sale would damage competition and allow Verizon to “accumulate even more spectrum on top of an already dominant position.” Sprint and MetroPCS have also spoken out against the deal, which was forged prior to the collapse of the AT&T/T-Mobile USA merger.