Time Warner Cable has announced the company will start charging most customers a monthly fee for broadband cable-modems. The monthly rate for customers with high-speed internet service will be $3.95, which new customers who have signed up within the last year have already been paying. It’s not clear whether or not Time Warner will offer upgraded modems for older models. However, TWC representatives said customers are welcome to purchase their own modems to bypass the monthly fee. An analyst says the monthly charge will increase TWCs annual revenue by about $300 million. Customers with Connected Learning, SignatureHome, Starter Internet and some IntelligentHome services will not be charged. Approved DOCSIS cable modems range from about $50 to $150 and can be purchased at retailers such as Radio Shack, Best Buy, and Amazon.