Comcast says it's begun offering gigabit internet service in the Chicago metropolitan area as part of a multi-city trial period. This follows the telecom’s ongoing gigabit tests in Atlanta and Nashville, which both started earlier this year. Comcast is delivering the 1Gbps speeds by relying on DOCSIS 3.1, a new modem standard for transmitting data through traditional coaxial cable lines that is in some situations even faster than fiber optic cables. This means Comcast doesn’t need to lay down new wires or rework any other aspects of its existing infrastructure.

Unfortunately, the service is quite expensive. It will cost $140 a month without a contract, and that’s excluding additional taxes and fees. In Atlanta and Nashville, where competition for fiber internet is higher, Comcast offers its gigabit service for $70 a month so long as you lock into a three-year contract. No such contract option exists for Chicago customers.

Comcast is charging customers in Chicago twice as much as those in Atlanta and Nashville

However, Comcast told The Consumerist, "As these are advanced consumer trials, we are testing different prices and promotions in different markets." Still, it’s all about competition. Atlanta is slated to get AT&T’s gigabit internet services, while Nashville already has Google Fiber. So Comcast likely sees its three-year promotion in those cities as a way to retain customers. AT&T offers its gigabit service in Chicago already for just $90 a month. So Comcast may be just testing the waters there briefly before it feels the need to lower its rates.