A method and system of transmitting messages include requesting to submit a first request for transmitting a first message and to submit a second request for transmitting a second message until there is no first collision detected between the submitted first and second requests upon receipt of the submitted first and second requests. A first-stage differential amplifier A1 is provided in close proximity to a final-stage differential amplifier A4 so that distances between adjacent differential amplifiers are substantially equal to each other. The component signals are then adjusted for signal losses. These closely machined bushings are adapted to receive the shaft which extends from the ends of the hollow tube. Thus, it is possible to reliably keep the spaced state between the photosensitive drum and the charging roller. In one embodiment, a method includes providing a semiconductor substrate having a channel body of a transistor device disposed on the semiconductor substrate, the channel body comprising silicon, forming a cladding layer comprising germanium on the channel body, and annealing the channel body to cause the germanium to diffuse into the channel body.