Verizon Wireless has silently modified its Edge early upgrade program by cutting the wait time to upgrade smartphones from six months to just 30 days.

Verizon Wireless, the biggest U.S. carrier, has joined the war being played out for a bigger piece of the stagnant mobile carrier market share. T-Mobile triggered the competition with its "Uncarrier" strategy that put an end to contracts and offered early upgrades of smartphones. AT&T and Sprint joined the fray and started offering similar plans to keep up.

Recently, AT&T waged a verbal war with T-Mobile and Verizon was caught in the cross fires. The second biggest carrier announced its new slogan  claiming to be bigger and more reliable than Verizon and T-Mobile. Verizon kept out of the market share battle, but it seems not anymore.

Verizon Wireless modified its Edge early upgrade plans cutting down the waiting period for a smartphone upgrade from an earlier six months to just a mere 30 days. The move comes after T-Mobile took the curtains off its "Un-Carrier 4.0," which includes paying up to $650 to new customers for switching from AT&T, Sprint or Verizon.

In a statement to CNET, a Verizon spokesman said that the new change in plan " is currently a promotion but we have not set an end date. It is in response to our customer's requests regarding this popular payment and upgrade plan.....While it is important to understand what our competitors are doing, Verizon makes decisions based on what's best for both our customers and business."

The new plan only changes the wait time for users to upgrade their phone and does not change the payment deal. Subscribers are still required to shell out at least 50 percent of the phone's value before being allowed to upgrade.

Sprint also introduced a new "Framily" plan that saves up to $30 on a subscriber's monthly bill. Frequent moves by carriers to survive in the ever-growing wireless business have put end-users at an advantage.