A Methodology for Analyzing Power Consumption in Wireless Communication Systems

Energy usage has become an important issue in wireless communication systems. The energy-intensive nature of wireless communication has spurred concern over how best systems can make the most use of this non-renewable resource. Research in energy-efficient design of wireless communication systems show that one of its challenges is that the overall performance of the system depends, in a coupled way, on the different submodules of the system i.e. antenna, power amplifier, modulation, error control coding, and network architecture. Network architecture implementation strategies offer protocol software implementors an opportunity of incorporating low-power strategies into the design of the network protocols used for data communication. This dissertation proposes a methodology that would allow a software protocol implementor to analyze the power consumption of a wireless communication system. The foundation of this methodology lies in the understanding of the formal specification of the wireless interface network architecture which can be used to predict the performance of the system. By extending this hypothesis, a protocol implementor can use the formal specification to derive the power consumption behaviour of the wireless system during a normal operation (transmission or reception of data). A high-level formalism like state-transition graphs, can be used to track the protocol processing behaviour and to derive the associated continuous-time Markov chains. Because of their diversity, Markov reward models(MRM) are used to model the power consumption associated with the different states of a specified protocol layer. The models are solved analytically using the Mobius performance and dependability tool. Using the MRM accumulation and utilization measures, a profile of the power consumption is generated. Results from the experiments on the protocol layers show the individual power consumption and utilization of the different states as well as the accumulated power consumption of different protocol layers when compared. Ultimately, the results from the reward model solution can be used in the energy-efficient design of wireless communication systems. Lastly, in order to get an idea of how wireless communication device companies handle issues of power consumption, we consulted with the wireless module engineers at Siemens Communication South Africa and present our findings on current practices in energy efficient protocol implementation

A Methodology for Analyzing Power Consumption in Wireless Communication Systems

We propose a methodology that allows software protocol implementors a means of analyzing power consumptions in wireless communication systems. The energy intensive nature of wireless communication has spurred much concern over how best systems can make the most use of this nonrenewable energy source. The methodology involves describing the logical flow of protocol data units through the protocol layers based on their formal specification. Here after, the state diagrams of the protocol layers are derived from this logical description. These diagrams provide the schema for the continuous-time Markov chains that enable the capturing of the protocol layer's behaviour. Markov Reward Models are then specified by defining the Markov chains that allow for the modelling of power consumption as a reward. Modelling power consumption this way allows for the investigation of the power factor, power level analysis, and power consumption comparison of the radio interface protocol layers