This week, Comcast became the first cable operator in the nation to deploy wireless broadband services that do not rely on Wi-Fi hotspots, as the company began offering wireless Internet services in the Portland, Oregon market that compete directly with comparable, existing services provided by Verizon and other wireless carriers. The service, which operates via cards that are plugged into laptop computers, is the first to be offered by a cable company via WiMax technology and boasts transmission speeds in excess of 4 Mbps. Known as “Comcast High-Speed 2go,” the service will be carried over the 4G network of Clearwire Corp., a partnership among Comcast, Sprint Nextel, Time Warner Cable, Google, Bright House Networks, and Intel. The group intends to deploy a national wireless broadband network based on WiMax. While Comcast’s service compares to similar offerings by Verizon and AT&T that also require the use of laptop cards, both mobile phone carriers have laid out plans to roll out 4G wireless broadband services, based on long-term evolution (LTE) technology, which would eventually compete against the WiMax offerings of Clearwire and its partners. (Verizon hopes to launch its LTE network next year, while AT&T intends to roll out its service within two years.) Terming the Portland deployment as the “first step” in a larger launch, a Comcast spokeswoman said her company intends to expand the service to Philadelphia, Atlanta, Chicago, and other major markets by the end of this year.