The plate spring may have: an inserting portion having a hole to be able to be fitted on the bolt; a bending portion extending from the inserting portion and having a protrusion with a predetermined radius; and a fixing portion extending from the bending portion to protrude toward the fastening groove or to be inserted in the fixing groove.

The fixing assembly may further include a flat washer fitted on the bolt after the spring washer.

The fixing assembly may further include a snap ring configured to prevent the spring washer and the plate spring, which are fitted on the bolt, from being separated from the bolt.

The fixing bracket may have: a protrusion formed at a side in the width direction of the fixing bracket; and a groove formed at the other side in the width direction of the fixing bracket.

The plurality of fixing brackets may be coupled to each other by inserting the protrusion formed at any one fixing bracket into the groove formed at another fixing bracket.

Chain holes may be formed through the protrusion and the groove, when the protrusion formed at any one fixing bracket is inserted in the groove formed at another fixing bracket, the positions of the chain holes are aligned.

The device may further include the connecting brackets disposed around the outer surfaces of the fixing brackets and configured to be coupled to the communication equipment.

The connecting bracket may have: a base having a surface coupled to the communication equipment; and a fastening protrusion formed on the other surface of the base and inserted in the fastening groove of the fixing bracket.