A polymer comprising those selected from the group consisting of at least one of Formula, Formula, or mixtures thereofwherein each R1 to R10 is independently hydrogen, alkyl, aryl, alkoxy, halogen, arylalkyl, cyano, or nitro providing that R1 and R2 exclude halogen, nitro and cyano; a and b represent the number of rings; and n represents the number of repeating groups or moieties. A device, such as a switch for example, is connected to the continuous flexible bus. The system may also use differential encoding and decoding to eliminate the effects of frequency uncertainty. The assist circuit is isolated from latch circuit when latch node is being pull down to guarantee that pull down circuit can overcome pull-up circuit. To solve this problem, a communication apparatus notifies a change to power save mode by an ATIM packet, RTS packet, or null packet. Other devices, systems, and methods are disclosed.