Verizon is in the process of migrating their FiOS network from BPON to GPON (Gigabit Passive Optical Network) fiber technology. Their current BPON technology splits 622Mbps downstream and 155Mbps upstream among 32 users. GPON technology will allow them to offer 2.4Gbps downstream and 1.2Gbps upstream among 32-64 users (eliminating ATM, making it also more efficient).

The company has been testing the technology in a number of communities, with some employees having 100Mbps access. Verizon initially focused on California, Maryland, Massachusetts, New Jersey, New York, Rhode Island, Pennsylvania, Virginia and Texas, stating late last year, and all new 2008 installs in those States will be GPON.

You likely won't see any new speeds at first, as the upgrades are a way to "future proof" the network. 100Mbps connectivity may emerge eventually, but even Verizon admits that such a speed is more a marketing weapon than anything else at this point. When it is deployed, Verizon says limited demand will have them employing the over-subscription model.

While AT&T offers slower end-user bandwidth via VDSL, they'll also be making some substantial investment in GPON toward the tail end of this year, according to Light Reading. The report says they'll be installing Alcatel-Lucent and Ecricsson GPON in an uncertain number of greenfield (new home) fiber-to-the-home (FTTH) deployments. That's not as exciting as it could be, given those users are capped at 10Mbps worth of usable data bandwidth.

As AT&T told us last October, roughly a million of the eighteen million homes they plan to pass by the end of this year are fiber to the home. Hopefully they eventually unleash the potential of those connections.