still in dispute. In its 2003 response, the FCC failed to offer a means of resolving the disputes over network unbundling. 20 Rather than clearly identifying the network facilities that must be unbundled, its 2003 rules left the final decisions to state regulators. After first signaling its decision in February 2003, the com- mission waited until August to publish 600 pages of new rules containing a large number of ambiguities. For instance, it had announced in February that it would no longer require the incumbents to share their copper loops with entrants, thereby denying the entrant the opportunity to use only the upper frequencies required to deliver new "broadband" services. ² 1 In the final rule, it allowed entrants to continue line sharing to serve their exist- ing customers for an indefinite period and required the incumbents to offer "line splitting" on lines that they lease to competitive local exchange carri- ers (CLECs), thereby enabling these lessees to share their lines with third- party suppliers of broadband services. Given the ambiguities in this newest version of the unbundling rules and the decision to leave important decisions to the states, they were Opening Telecom Markets: The 1996 Telecommunications Act appealed to the federal courts once again. In 2004 the D.C. Circuit, in a stinging rebuke to the commission, overturned the latest FCC attempt to establish the dimensions of network unbundling, but it left intact the deci- sion to end line sharing. In December 2004, the FCC was in the process of rewriting the rules once again, but it is now clear that the degree of network unbundling will be sharply reduced, particularly the requirement that the incumbent local carriers offer the entire complement of network facilities as an "unbundled network element platform" (UNE-P). As I discuss in chapter 5, this plat- form has generally been made available to entrants at discounts of 50 to 60 percent from average retail revenues per line, thereby providing the entrants with a substantial prospective m