. Fixed telecommunications systems operate at lower transmission power compared with wireless systems. Power consumption features promi- nently in mobile devices usage and stand-by times and how often recharging is necessary. It also features in operating costs of mobile operators as electricity usage can be quite high. Power consumption is significant also for power-limited applications. Most battery-powered wireless devices are power-limited, and it follows that technologies which use less power can be advantageous in these conditions. Therefore a system which provides high transmission rate at the expense of high power consumption may be discounted in favour of a low power consumption system with sufficient transmission rate. An example is advanced-antenna sys- tems which can deliver higher transmission rates at the expense of higher power consumption. Technology, Business and Policy Power consumption is also a function of processing complexity. Generally high transmission rates require a large amount of signal processing, and therefore battery consumption. Therefore where high transmission power is not an important factor, such as sensor networks, simpler technologies with lower power consumption are more desirable. Quality of Service Another technological parameter of interest is QoS. QoS has several dimensions and includes the probability that a message arrives in error, the delay in receiving a message, as well as the quality of sound or video as perceived by an end-user. Errors in communications can lead to dropped calls, retransmission requirement, loss of data, and therefore degraded quality. Excessive delays may also contribute to lost data, or tem- porary disruption of playback and therefore bad quality. Quality of audio and video reproduction can also be impacted by source coding techniques and reproduction fidelity. All of these contribute to QoS and quality of experience and can therefore be important in com- paring two broadband telecommunications systems. Delay is of particular importance to many