Ill. Admin. Code tit. 83, § 790.330
d) Equipment that can be collocated. An ILEC shall permit the collocation of any type of equipment for interconnection or access to unbundled network elements in a manner consistent with the Act and Federal Act. Equipment necessary for interconnection and access to unbundled network elements includes, but is not limited to:
1) Caged collocation;
2) Shared collocation. Shared collocation arrangements must be consistent with the following:
A) Telecommunications carriers sharing physical collocation space may, at their option:
4) Adjacent space collocation. With regard to adjacent space collocation, an ILEC must:
D) Give an interconnecting carrier that has initiated collocation in an adjacent space or facility the option of remaining in the adjacent space collocation arrangement or moving into the relevant central office or other premises upon space becoming available inside the relevant central office or other premises; interconnecting carriers opting to move shall pay costs associated with the move.
g) Space allocation and exhaustion. ILECs shall apply the same space reservation policies to telecommunications carriers as it applies to itself. ILECs shall:
9) Remove all unused obsolete equipment from the ILEC premises and make such space available for collocation before making a determination that space in the premises is legitimately exhausted. The ILEC may not make only minimal or token use of otherwise obsolete equipment to avoid having to remove the particular equipment and make space available for collocation. The removal of unused obsolete equipment shall not cause a delay in the ILEC's response to a telecommunications carrier's application or in provisioning collocation arrangements.
A) In making the determination of whether space is legitimately exhausted, the ILEC may retain a limited amount of floor space for its own uses. Specifically, the ILEC may reserve space for transport equipment for one year of anticipated growth, space for digital cross-connect system equipment for three years of anticipated growth, and space for switching, power, and main distribution frame equipment for five years of anticipated growth. In those premises where collocators existed on May 1, 2003, the space reservation time limits shall be calculated beginning on May 1, 2003. In those premises where collocators did not exist on May 1, 2003, the space reservation time limits shall be calculated beginning on the date upon which the first telecommunications carrier applied for collocation in the particular premises.
10) Denial of an application for collocation. There shall be a rebuttable presumption that space is available for physical collocation in an ILEC's premises.
B) If an ILEC denies a collocation request, any charges collected with the application will be returned to the telecommunications carrier, except for any amount recovering the ILEC's cost to review the application. The ILEC shall provide, subject to any appropriate proprietary protections, the following information with the notification of the denial:
iii) total amount of space at the premises;
h) Waiver procedures.
1) ILECs must petition for a waiver of the requirements to provide physical or virtual collocation if the remaining space in a central office that can be used for physical collocation is less than 50 square feet. The Commission shall grant a waiver of the requirements to provide physical or virtual collocation if the FCC has granted a waiver due to lack of space or, after hearings, the Commission finds that the LEC has demonstrated that:
4) The ILEC has the burden of proof in showing that these requirements have been met. The ILEC shall submit floor plans, sworn affidavits, written testimony and any other evidence necessary to meet its burden of proof. The ILEC's sworn testimony shall describe and identify: