Dirk Kosiankowski

Energy Consumption of Telecommunication Networks and Related Improvement Options

In this study, energy consumption of a universal network operators broadband telecommunication (TC) network, including the home networks that are required for the use of services over a period of approximately one decade is predicted, whereby it is assumed that no measures for an energy-efficiency increase are taken. It becomes obvious that home networks consume the largest share of energy in TC networks. Concerning the network sections under the responsibility of network operator, highest energy consumption shares are observed in the fixed and mobile access networks with a huge number of distributed network elements in the field. The highest energy consumption growth rates are foreseen in the data centers and IP backbone networks. Methods for reducing energy consumption are being classified and metrics for energy-related assessment of networks are compared. Furthermore, challenges and opportunities for energy-related improvements are discussed with respect to different network sections. A projection into the future shows high-energy-saving potential when combining different energy-reducing methods, such as load-adaptive networking and energy-aware system design. A brief view on related standardization activities shows high interest of standardization bodies in energy consumption of TC networks and confirms its current importance.

Effects of network node consolidation in optical access and aggregation networks on costs and power consumption

The increasing demand for higher bit rates in access networks requires fiber deployment closer to the subscriber resulting in fiber-to-the-home (FTTH) access networks. Besides higher access bit rates optical access network infrastructure and related technologies enable the network operator to establish larger service areas resulting in a simplified network structure with a lower number of network nodes. By changing the network structure network operators want to benefit from a changed network cost structure by decreasing in short and mid term the upfront investments for network equipment due to concentration effects as well as by reducing the energy costs due to a higher energy efficiency of large network sites housing a high amount of network equipment. In long term also savings in operational expenditures (OpEx) due to the closing of central office (CO) sites are expected. In this paper different architectures for optical access networks basing on state-of-the-art technology are analyzed with respect to network installation costs and power consumption in the context of access node consolidation. Network planning and dimensioning results are calculated for a realistic network scenario of Germany. All node consolidation scenarios are compared against a gigabit capable passive optical network (GPON) based FTTH access network operated from the conventional CO sites. The results show that a moderate reduction of the number of access nodes may be beneficial since in that case the capital expenditures (CapEx) do not rise extraordinarily and savings in OpEx related to the access nodes are expected. The total power consumption does not change significantly with decreasing number of access nodes but clustering effects enable a more energyefficient network operation and optimized power purchase order quantities leading to benefits in energy costs.

Comprehensive topology and traffic model of a nationwide telecommunication network

As a basis for meaningful simulation and optimization efforts with regard to traffic engineering or energy consumption in telecommunication networks, suitable models are indispensable. This concerns not only realistic network topologies but also models for the geographical distribution and the temporal dynamics of traffic, as well as the assumptions on network components and technology. This paper derives such a model from the practice of a large national carrier. Applying the network and traffic model, we demonstrate its use by presenting various optimization cases related to energy-efficient telecommunication. Here, we focus on load adaptivity by employing sleep modes to the network hardware, where several constraints on the reconfigurability of the network over time are considered.

Energy footprint of telecommunication networks

The energy consumption of telecommunication networks is forecasted over approximately a decade. The results show a high energy consumption share associated with the home networks and an overall growth if no countermeasures are taken.