Comcast Corp. is getting ready to trot out a usage-based broadband plan in Tucson, Ariz., that will start to match up customers' monthly data allowances with the speeds of their Internet service packages.

On the high end, customers who take Comcast's fastest Docsis 3.0 tier in Tucson (105 Mbit/s downstream by 20 Mbit/s upstream) will be subject to overage charges ($10 for each bucket of 50 gigabytes) if they gobble up more than 600GB during a given month. The operator's 50Mbit/s downstream tier will be combined with a monthly data threshold of 450GB. All other cable modem tiers will be saddled with a monthly ceiling of 300GB before the overage charges factor in. Comcast has begun to introduce a D3 tier that offers 305 Mbit/s down by 65 Mbit/s upstream, but has not yet launched it in Tucson. (See Comcast Revs Up Pricey 305-Meg Tier.)

Here's how the policies will stack up in Tucson starting Oct. 1, according to this customer Web page (Hat tip: Broadband Reports):

Table 1:

Tucson is the second Comcast market to test out new usage-based data policies that replace a monthly 250GB hard cap designed to keep "excessive use" in check. Under that old policy, customers were not hit with overage fees, but they did risk getting service switched off if they exceeded the cap repeatedly. (See Comcast Draws the Line at 250GB.)

The first Comcast market to try a new soft cap/overage fee policy was Nashville, Tenn., where Comcast is also charging $10 for 50GB of data when customers exceed their ceilings. A big difference is that the ceiling in Nashville is 300GB for all cable modem tiers. (See Comcast Turns On Usage-Based Broadband.)

But Comcast is also using some of the same rules in both markets. For example, Comcast won't bill customers the first three times they exceeded their monthly allowance during a 12-month period and will alert customers by email and via in-browser notices when customers approach 90 percent and 100 percent of the soft cap.

Comcast has suspended its old 250GB excessive use policy for residential broadband as it kicks the tires on these new usage-based plans. Comcast declined to identify where else it will introduce these new policies and when, but the company said in mid-May that it would pilot "at least two approaches" in different markets over the next few months. (See Comcast to Raise Caps, Test Overage Fees .)

Other MSOs, notably Mediacom Communications Corp., have introduced similar policies. Suddenlink Communications has suspended its usage-based plan as it looks to hire a third party to validate the accuracy of its broadband meter. (See Suddenlink Puts Broadband Overage Fees on Ice , 4 ISPs That Netflix Hates and Mediacom Unleashes Usage-Based Broadband .)

— Jeff Baumgartner, Site Editor, Light Reading Cable