The invention is directed to an expandable stent for implanting in a body lumen, such as a coronary artery, peripheral artery, or other body lumen. The physical layer and link layer include enhancements that interact with one another to cause the link layer to inhibit ARQ operations while error recovery operations are pending at the physical layer. A vertical array of antenna elements is mounted along the vertical focal line to provide electronic scanning in elevation. Improved blood circulation may reduce the occurrence of undesirable complications such as deep vein thrombosis, ulcers, and the like. The metal mesh belt includes a material having a thermal conductivity substantially higher than that of the corresponding steel belt and having a thermal expansion coefficient approximately equal to that of the corresponding steel belt. A dynamic pressure compensation module receives the oxygen sensor signal and the pressure signal and to perform dynamic pressure compensation.