The start at $50 for 5GB of data per modem, according to Verizon, although business users may be able to negotiate special terms that include pooling of data across a group of workers.

When informed of Wyse's problem, a Verizon Wireless spokeswoman said: " Our 4G network is up and running. I apologize for the experience your reader describes...." She offered to have a Verizon technician work with Wyse to resolve the problem.

When the nearly two-day outage was reported as over on April 28, a Verizon spokesman also said that the LTE network was "up and running," with normal service for ThunderBolt smartphone users who had noticed data slowdowns to 3G or slower service.

At that time, he noted there might be lingering problems for USB modems that would improve over time. "Laptop users with USB modems may need to re-connect to the network when moving between 3G and 4G," the spokesman said on April 28. "This will continue to improve."

Reconnecting each time a user moves from a 3G to 4G tower can be confusing and time-consuming, users have complained in online comments. Many customers bought the LTE modems for LTE speed, which is 10 times faster than 3G and offers up to 9Mbps on downloads and up to 5Mbps on uploads, according to Verizon. Such speeds are helpful in transferring media-heavy files, including video.