A spine stabilization rod assembly comprises a rod and a sleeve member. The lighting unit includes a light source and an optical element. A transponder in accord with an embodiment of the invention prevents BER from exceeding a threshold value of BER whether RXP or OSNR, or both, remain constant, change continuously, or change intermittently. The first set of uplink contention slots is communicated to the first set of devices. An additional force concentrating treatment apparatus is also presented.