In today's semiconductor-based computer and communication technology, system performance is determined primarily by two factors, namely on-chip and off-chip operating frequency. In this dissertation, time-domain measurement-based methods that enable gigabit data transmission in both the IC and package have been proposed using Time-Domain Reflectometry (TDR) equipment. For the evaluation of the time-domain measurement-based method, a wafer level package test vehicle was designed, fabricated and characterized using the proposed measurement-based methods. Electrical issues associated with gigabit data transmission using the wafer-level package test vehicle were investigated. The test vehicle consisted of two board transmission lines, one silicon transmission line, and solder bumps with 50um diameter and 100um pitch. In this dissertation, 1) the frequency-dependent characteristic impedance and propagation constant of the transmission lines were extracted from TDR measurements. 2) Non-physical RLGC models for transmission lines were developed from the transient behavior for the simulation of the extracted characteristic impedance and propagation constant. 3) the solder bumps with 50um diameter and 100um pitch were analytically modeled. Then, the effect of the assembled wafer-level package, silicon substrate and board material, and material interfaces on gigabit data transmission were discussed using the wafer-level package test vehicle. Finally, design recommendations for the wafer-level package on integrated board were proposed for gigabit data transmission in both the IC and package.