Radiowave propagation characteristics inside a modern office electromagnetic environments (EME) were experimentally investigated. To this end, reflection and transmission parameters across a 2.5 GHz bandwidth (including both GSM and ISM bands) were measured across a scanned volume between a fixed transmitting antenna and a mobile receiver. Single-input-single-output (SISO) as well as single-input-multiple-output (SIMO) channels measurements were performed using an automated data acquisition system, based on a four-channel vector network analyzer. A scanning multi-channel antenna array was constructed used to collect channel measurement matrices. Multi-path characteristics were extracted by subtracting corresponding measurement data taken inside a fully anechoic chamber for a carefully replicated measurement set-up from the office room data. Care was taken to minimize external ambient effects and their possible perturbations by performing automated measurements under remote control at nighttime. It was found that the statistics of the scattered component in the field transmitted across the room can be closely approximated by a negative exponential distribution, demonstrating that the scattering can be considered as close to isotropic across the scanned volume. However, notable deviations occur closer to the office floor and in the vicinity of metallic office furniture, as can be expected. It is found that propagation characteristics can be characterized by an input impedance and, to some extent, a quality factor which describe the mismatch and confinement of scattered energy inside the office room, respectively. The results are useful for instrumental in the study and mitigation of signal outages and bit error rates in indoor environments for the deployment of short-range wireless office information and sensor networks, including IEEE 802.11a/b/g/n wireless local area network (WLAN), IEEE 802.15.1 Bluetooth, and IEEE 802.15.4 ZigBee.