Global warming, climate change and their associated impact on the existence of human civilization are crucial in the present world. With the advent of development, industrialization and its eventual energy consumption are growing enormously with a rate far beyond our expectation. This lead to emission of GHG (Green House Gases) that is primarily responsible for global warming and climate change. In this process, the concept of green technology is gaining its necessity for environmental sustainability. Energy preservation along with low carbon emission has become compelling challenges for industries and organizations. ICT plays an integral role in reducing harmful environmental effect of other industries. Although ICT is deployed to’ green’ the technology, as an industry, ICT itself is responsible for significant adverse impact on the environment. Wide application of online services, social networking, e mailing and other web based activities lead to extensive deployment of cloud hosting that caters for several data centers all around the globe. These data centers are massive power user and very often consume more power than the cities they are located in. So data center deployment decision is driven by availability of cheap electrical power and or a natural means of cooling. Recent studies found that carbon dioxide (CO2) emissions from data centers alone surpass emissions from many individual countries (note that this does not include CO2 emissions from other global ICT infrastructure) (Yousif, 2009). Moreover, ICT equipment contains toxic substances such as lead and mercury, much of which enters the environment as e waste. Diverse and extensive footprint of ICT demands for comprehensive efforts by researchers, technologists, developers, consumers and politicians for green and sustainable ICT. A wide range of initiatives, like, deployment of energy efficient resources and equipment, involving virtualization and autonomic power optimization, developing lower-voltage equipment, increased integration (system-on-a chip), power-aware ICT (both hardware and software), and motivation of end user for energy conservation can ensure green ICT. Using advanced cooling technology and power generation equipment along with adoption of physical layout to reduce external/internal heat and optimizing physical placement of resources can improve the efficiency of ICT operation to a greater extent.
2. The concept of Green ICT
Green ICT, or sustainable ICT, is a recently emerged topic that addresses the role of ICT for achieving Sustainable development goals. Green ICT is the study and practice of environmentally sustainable computing or IT. It aims to make the overall impact of ICT, clear, environmentally sustainable and positive through decreasing resource intensity and encouraging resource consuming lifestyles. To San Murugesan, it includes designing, manufacturing, using, and disposing of computers, servers, and associated subsystems such as monitors, printers, storage devices, and networking and communications systems — efficiently and effectively with minimal or no impact on the environment. It is evident that ICT has the vast potential to innovate climate safe technology for other
* Divisional Engineer, Bangladesh Telecommunications Company Limited
WORLD TELECOMMUNICATION AND INFORMATION SOCIETY DAY 2014
It is evident that ICT has the vast potential to innovate climate safe technology for other industries. But at present, the overwhelming challenge of ICT sector’s own emission needs to be addressed. Innovations in green solutions in telecommunication networks (e.g. converged, flatter and highly integrated network), energy preservation, smart cooling technologies, software development for power conservation and deployment of high efficiency equipment contribute to environment friendly green ICT. If such green ICT can be combined with other technologies to reduce their emission it can lead to greener solutions. However, reducing carbon emissions will require changes in lifestyle and behavior, but changes in management practices and policy initiatives can also have a positive impact. Green ICT can help, either directly, by reducing the ICT sector’s own energy requirements; or indirectly through using ICTs for carbon displacement, or in a systemic way, by providing the technology to implement and monitor carbon reductions in other economic sectors. For example, studies show that monitoring and control using ICT can reduce energy use in buildings by up to 17 % and reduce carbon footprint in transport logistics by up to 27 %. With smart power networks it is possible to control electricity consumption dynamically, resulting in energy savings and more efficient investments. Smart electricity meters which provide consumers with information about energy use can reduce consumption as well as network operators’ energy losses.
3.1 ICT and environment
It is estimated that ICT as an industry contributes to around 2% to 2.5% of GHG emissions every year. Manufacturing of ICT products, their use (energy use and cooling method), disposal, all steps are associated with massive carbon footprint and emission of toxic material to the environment that are not bio degradable. Moreover, the ICT sector’s emissions are expected to increase to nearly double – to about 4% – by 2020 (SMART 2020
report, 2008). ICT is changing its attribute rapidly and a wide variety of gadgets are added for the consumers. 2010 has been addressed by many in ICT sector as ‘Year of Cloud’. Arrival of iPad, growth in netbooks and other tablet computers lead to extensive use of cloud hosting technology. It accounts for massive power consumptions through numerous datacenters. Google is perhaps the most famous cloud-based company to demonstrate the potential of a cloud platform to drive a hugely successful business model. All of Google’s signature products - Gmail, Google Documents and Google Earth - are delivered from the cloud. Its ambitious project to create a digital library will be entirely hosted by servers storing most of the world’s published work, all in digitized form (Greenpeace report, 2010). Millions of consumers access the ‘cloud’ to use social networks, watch stream video, download music, books, and check mail. Facebook, Flickr and Picasa also involve clouds for storing thousands of digital photos online.
3.2 Cloud Hosting and its impact on environment
The term cloud, or cloud computing, used as a metaphor for the internet, is based on an infrastructure and business model whereby - rather than being stored on user’s own device - data, entertainment, news and other products and services are delivered to user’s device, in real time, from the internet. With the growth of the cloud comes an increasing demand for energy. Unfortunately, the cloud is growing at a time when climate change and reducing emission from energy use is a paramount concern. Cloud computing deploys data centers to cater massive storage that consume tremendous amounts of energy. The companies rarely seek for a green power source to fuel these data centers. For instance, Facebook, in 2010 commissioned a new data centre in
Oregon and committed to a
power service provider agreement with Pacific Corp, a utility that gets the
majority of its energy from coal-fired power stations, the ’ largest source of
greenhouse gas emissions . Yahoo, however, choose to build a data center
outside United States , driven by a hydro-electric power
plant that dramatically Buffalo, New York
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reduces its carbon footprint. So if truly green cloud is to be provided, the cloud providers must drive investments near renewable energy sources. In addition, they must be involved in setting the policies that will drive rapid deployment of renewable electricity generation economy-wide, and place greater R&D into storage devices that will deliver electricity from renewable sources 24/7.
3.3 Projection of Carbon footprint of ICT industries
SMART 2020 Report issued by The Climate Group and the Global e-Sustainability Initiative (GeSI) in 2008, reveals that
• PC ownership will quadruple between 2007 and 2020 to 4 billion devices, and emissions will double over the same period, with laptops overtaking desktops as the main source of global ICT emissions (22%).
• Mobile phone ownership will almost double to nearly 5 billion accounts by 2020, but emissions will only grow by 4%. Broadband uptake will treble to almost 900 million accounts over the same period, with emissions doubling over the entire telecoms infrastructure. SMART report also predicts the carbon footprint of ICT industries itself that is depicted in table 1. However, the ICT sector has high potential to emission reductions five times the size of the sector’s own footprint, up to 7.8 GtCO2e, or 15% of total BAU (business as Usual) emissions by 2020 (SMART 2020 report, 2008). The study posits that innovation form the ICT sector, combined with increased use of renewable energy can put the world on a more sustainable path and help keep global temperature rise below 2°C threshold .
4.1 Initiatives for green ICT
Initiatives for green ICT are comprehensive efforts by ICT industry, environment preserving agencies, different governments, and International organizations, like, ITU. Nevertheless, the consumer lifestyle should also be green ICT compliant. Such initiative first started far back in 1992 with energy star logo. US Environment protection agency started this voluntary labeling program to promote and recognize energy efficiency in computer monitors, climate control equipment and other environment friendly technologies. It yields widespread adoption of sleep mode in consumer electronics. Concurrently, the Swedish organization TCO Development launched the TCO Certification program to promote low magnetic and electrical emissions from CRT-based computer displays. Murugesan, in 2008, devised four layouts to address the adverse effect of computing on environment: Green use, green disposal, green design, and green manufacturing. Green computing can develop solutions by "aligning all IT processes and practices with the core principles of sustainability, which are to reduce, reuse, and recycle; and finding innovative ways to use IT in business processes to deliver sustainability benefits across the enterprise and beyond". It should incorporate end user satisfaction, management restructuring, regulatory compliance, and return on investment (ROI).
4.2 Industries to address green ICT
Various Industries came into operation for greening the ICT. The leading industries in this field are Climate Savers Computing Initiatives (CSCI), The Green Electronics Council, The Green Grid, Green Comm. Challenge, Transaction Process Performance Council Table 1: Projection of Carbon footprint of ICT industries
2007 (Mt CO2e)
2020 (Mt CO2e)
World 830 100% 1430 100%
Server farms/Data centers 116 14% 257 18%
infrastructure and Devices
307 37% 358 25%
PCs and Peripherals 407 49% 815 57%
WORLD TELECOMMUNICATION AND INFORMATION SOCIETY DAY 2014
(TPC), Spec Power etc. Among them, CSCI, established in 2007, aims to reduce the electric power consumption of PCs in active and inactive states. It provides a catalog of green products from its member organizations. WWF is also a member of the computing initiatives. The Green Electronics Council assists the purchase of ‘greener’ computing systems through Electronic Product Environmental Assessment Tool (EPEAT). Products are rated Gold, Silver, or, Bronze, depending on the number of optional criteria they meet to measure products efficiency and sustainability attributes. The Green Grid, a global consortium, founded in 2007, is dedicated to advancing energy efficiency in data centers and business computing ecosystems. Its main focus is improving datacenter infrastructure efficiency. The founding key companies of green grid are AMD, APC, Dell, HP, IBM, Intel, Microsoft, Sun Microsystems etc. Apart from ICT companies green grid incorporates hundreds of members including end-users and governments organizations. SPEC Power is the first industry standard benchmark to measure the power consumption in relation to performance for server-class computers.
4.3 Green Computing methods
• Product longevity
Product longevity is central for green computing. Product upgradability and modularity along with prolong lifetime of equipments reduces the adverse environmental effect. For instance, manufacturing a new PC contributes a greater footprint than manufacturing a new RAM. It is seen that the PC manufacturing process accounts for seventy percent of the natural resources used in the life cycle of a PC (Gartner, 2009). So up gradation and modularity, instead of complete replacement of the equipment should be the primary focus.
• Data center design
In 2010, between 1.1% and 1.5% of the world’s total energy use was consumed by the data centers. The U.S. Department of Energy estimates that data center facilities consume up to 100 to 200 times more energy than standard office buildings. There is no alternative to design energy efficient data centers. The U.S. Department of Energy identifies five primary areas for energy efficient data centers:
• Information technology (IT) systems
• Environmental conditions
• Air management
• Cooling systems
• Electrical systems
• On-site electrical generation and recycling of waste heat. Emphasis should be given on space utilization, software and deployment optimization, actual location, configuration and construction of the building for energy efficient data center design. Larger server centers should be located where land and energy are inexpensive and are readily available. Moreover, local availability of renewable energy, climate that allows outside air to be used for cooling, and locating them in a place where the heat produced can be used for other purposes are key factors for environment friendly site allocation. Data centers can potentially
improve their energy and space efficiency through techniques such as storage consolidation and virtualization. With the aid of a self-styled ultra efficient evaporative cooling technology, Google Inc. has been able to reduce its energy consumption to 50% of that of the industry average.
• Algorithmic efficiency
Algorithmic efficiency determines the amount of computer resources required for any given computing functions. For instance, switching from a slow (linear) search algorithm to a fast (hashed or indexed) search algorithm can reduce resource usage substantially. A study by a physicist at Harvard, estimated that the average Google search released seven grams of carbon dioxide (CO_) (Fox news, 2009). Google, however, argued that a typical search produces only 0.2 grams of CO_ (official Google blog, 2009).
• Resource Allocation
Another effective way for increasing efficiency is resource allocation. Allocation
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Algorithms, for example, can be used to route traffic to data centers where electricity is less expansive or produced in a more environment friendly way. However, this technique does not reduce energy usage rather cut down the energy cost of the company or ensures utilization of environment friendly energy sources.
Computer virtualization refers to abstraction of computer resources; a process where two or more logical computer systems are run in one set of physical hardware. So a system administrator can integrate several physical systems into virtual machines on one single, powerful system thereby unplugging the original hardware and reducing power and cooling consumption.
• Terminal servers
With terminal servers the users at the terminals are connected to central server where all the computing is performed but the user experiences the operating system in the terminal. It can be combined with thin client that uses about one eighth of the energy of a normal workstation thereby reducing energy consumption and cost.
• Power management
Reducing power usage is central for green computing. The Advanced Configuration and Power Interface (ACPI), an open industry standard, allows a system to automatically turn-off components such as monitors and hard drives after set periods of inactivity. In addition, a system may hibernate, when most components, including the CPU and System RAM, are turned off. Intel processor offers ‘Speed Step’ to regulate its voltages supplied depending on the workload. This voltage regulation is also called ‘under volting’ that allows the CPU to adjust its voltage supply thereby reducing electricity consumption and heat production.
5.1 Green Initiatives in Telecommunication Networks
Apart from above techniques a more integrated effort is required in the telecommunication networks to reduce the Carbon footprint of the ICT industries. It requires combined drive by the vendors and the telecommunication operators. Innovation in green technology can be divided into two parts: 1) Network Architecture level, and 2) Network Element level. The first one refers to optimize organization of network elements, and the second one incorporates green technology in equipment level, board level, and chipset level. Hence, Network Architecture innovation has the potential to save 60%-80% power consumption. The network elements, on the other hand must be environmental friendly to support the network Architecture level Figure1. Power Saving Innovations  Power Saving and reduced energy consumption are primary concerns of green ICT. Network Architecture determines the scale of network energy consumptions. To optimize the network for reduced power consumption, emphasis is given on three levels of network: Access Network: Innovative wireless access architecture of C-RAN and green FTTx for fixed broadband. Core Network and Data centers: innovative architecture for data centers for converged core networks. Transport Network: A converged and flatter architecture for power saving.
5.2.1 Access Network green solutions
• C-RAN for wireless network Innovations
Network Deployment strategy with ‘large capacity, fewer site rooms’ can provide a greener and lower cost network for operators . C-RAN for wireless network can be a very
WORLD TELECOMMUNICATION ANDINFORMATION SOCIETY DAY 2014
effective technique for green innovation. It includes centralized processing, collaborative radio, real time cloud computing infrastructure, and is environmentally clean system. In C-RAN RRU (Remote Radio Unit) is separated form BBU (Baseband Unit). RRUs are naturally cooled components that can be installed on outdoor/rooftop/pole and they can be connected to a set of BBUs in the central office via CPRI interface over optical fiber. So C-RAN architecture removes the requirement of site rooms and associated A/C in BTS sites. In addition, RRUs with high receiver sensitivity deployed closer to the antenna can save transmitter power thereby increasing the capacity of C-RAN based BTS/NodeB. Moreover BBU Pool offers converged network with higher network capacity. Figure 2: Typical C-RAN Deployment Topology vs. Traditional RAN Mode 
• FTTx : Green access innovation for fixed network
Development and convergence of core network demands for reduced access network complexity. In this process, PSTN, NGN and broadband access networks based on DSLAMs have converged into an FTTx network architecture that not only reduces access network complexity and but also cost. FTTx deploys larger capacity converged OLT sites that require reduced number of switches. Such Flatter network leads to decreased energy consumption. Figure 3: FTTx network for multi access network convergence
5.2.2 Converged Core Network and Innovative Datacenter for power saving
Core network comprises a wide variety of network elements and equipment for data storage, service provision etc. So, converged, energy efficient data centers to provide core network functionality is the key element for energy saving. Data centers with bladed and virtualized IT accounts for lower server energy consumption. In addition, innovation in cooling system leads to further reduction of energy usage. For instance, ‘liquid cooling system’ with the cooling system to be located as close as possible to the main heat generation source, and ‘accurate winding’ that directs cool air to the server heat generating parts, reduce substantial energy usage.
5.2.3 Converged and Flatter Transport Network for Power Saving
The traditional transport layer comprises core layer, aggregation layer, and access layer. Innovation in Green technology omits the aggregation layer and the elements of core layer are directly connected to access layer thereby reducing the number of equipment required. In this flatter network, Aggregation equipment links, ports, routing and room space is reduced considerably leading to a power saving of as high as thirty percent. Nonetheless, it reduces cooling requirement, lessens network delay and jitter.
5.3 Green Technology in Network Elements
Network elements green technology involves greening in three levels: equipment level, board level, and chipset level.
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5.3.1 Equipment level green solutions
With the popularity and huge demand of wireless technology, mobile operators experience tremendous energy need to deploy different technologies (GSM/WCDMA/LTE) with multiple frequency resources (900m/1800m/2100m). SDR based wireless solution is a green initiative that supports multiple technologies and frequencies in the same equipment platform. Another prime way to reduce energy consumption is to reduce number of base stations, especially in low traffic cases, for example, in rural areas. High sensitivity receiver technology is a best solution in this regard. In rural areas, a 3dB increase can increase the coverage radius by 22%, which means a 45% coverage increase . It, in the long run, reduces number of base station and their associated energy consumption. Traffic volume in telecommunication network varies widely ranging from business hours to non-busy hours. RNC equipment technology can meet this criterion to optimize energy consumption through automatic and dynamic power control of equipment. Some boards with RNC functionality goes to sleep mode during low traffic volume and wakes up in business hours. Vendors introduce new equipment for base stations that adopt a wide range of operating temperature ranging from -10_ to +55 _. It reduces the dependency on air-conditioning thereby reducing energy consumption. In the fixed networks, transition from copper cable to fiber in the form of FTTx offers extensive reduction of energy by increasing more passive components in the network. This equipment also utilizes dynamic power control methods for reduced energy usage. Advanced system architecture to reduce redundancy, low power routers, effective thermal design, introducing sub-regional power supplies within equipment, and using highly integrated equipment are additional features of equipment green solutions. In addition, introduction of fan-less dual layer sub-rack architecture in equipment level results in extensive power saving.
5.3.2 Board Level Green Solutions
To reduce the number of base stations, and power usage, in the board level, the efficiency of power amplifier is increased considerably. Flexible resource allocation technique allows provision of baseband pool where all boards are controlled and monitored by the control module. The more the number of boards are on the pool the more power saving they provide. In wireless networks, with the ease of intelligent timeslot technology, during low traffic all the active user time slots can be consolidated to smaller number of timeslots and unused timeslots are shut down. Board density is increased by using more integrated chipset that provides multiple functionality on the same board. It reduces number of service cards and power usage.
5.3.3 Chipset level green solutions
One challenge in increasing power amplifier (PA) efficiency is that the efficiency is maximized at full output power and declines at lower outputs. But the equipment not always runs on full output. Green dynamic power technology is introduced that tracks the real time workload and adjusts the PA supply voltage accordingly. Thus efficiency is optimized in lower outputs as well. Moreover, ‘green’ chip set are developed with energy efficiency, high integration, sleep-mode capability, and provision of multi voltage operation for dynamic power control.
5.4 Green Solutions for Auxiliary facilities
Power efficiency in power transformer modules, intelligent cooling system and high efficiency environment friendly battery system along with green energy are necessary for a complete green Telecommunication network. The vendors now stress on use of renewable energy in the form of pure solar, hybrid solar and oil, hybrid wind and solar energy solutions etc. These
energy schemes can be customized depending on the availability of resources, and scale of economy of the customer. Innovation is required for green
systems as well. For instance, Li-Iron batteries have many ‘green’ advantages over
lead-acid batteries that are widely used in traditional telecommunication
networks. Li-Iron Batteries are safer, more environment friendly, and have higher
6. Regulatory and Policy Initiatives for Green ICT
It is evident that only technical efforts are not sufficient for sustainable green ICT initiative. A generic benchmark, universal solution, along with regulatory and policy initiatives are essential that requires comprehensive efforts by the technologists, researchers, end-users, telecommunication industries, environment
WORLD TELECOMMUNICATION AND INFORMATION SOCIETY DAY 2014
specialists, international organization and the governments around the globe, especially, from the developed countries responsible for larger carbon footprint. ITU as an International regulatory body takes several measures for green solutions. It deploys wide range of recommendation in the form of green ICT standards and supplements. For mobile terminals and other hand- held devices ITU recommends universal Power adapters and charger solutions (ITU-T L.1000). Almost all the smart phones and tablets now have same USB chargers. It reduces the number of power adapters and chargers produced and recycled leading to a green ICT solutions. Similarly, ITU recommends for External Universal Power Adapter solutions for stationary ICT devices (ITU-T L.1001). Such universal devices widen their application in more devices, enable their reuse, and increase their lifetime. It reduces the demand on raw materials and limits the production of e-waste. In addition, ITU provides information on recycling procedure for rare metals of ICT goods. ITU also recommends Direct Current (DC) interface between the power feeding system and ICT equipment connected to it. The specified interface is operated from a DC power source of up to 400 V to allow increased power consumption and equipment power density, in order to obtain higher energy efficiency and reliability with less material usage than using a lower voltage such as -48 VDC or AC UPS power feeding solutions (ITU-T L.1200). ITU suggests best practices for green data centers and energy efficiency metrics and measurement methods for telecommunication equipment. It also focuses on assessment of environmental impact of ICT goods, networks, services, projects, ICT in organizations, cities, countries and group of countries. It also provides methodology for assessment of such environmental impact.
Green ICT is inevitable in the present climate change scenario. The developed countries with extensive technological growth are associated with large carbon footprint. Unfortunately, the developing countries thriving for ICT penetration are mostly affected by global warming. So it is the primary responsibility of the developed countries to reduce carbon footprint. Invention and cost effective application of climate safe ICT is an overwhelming challenges for ICT experts. Fortunately, Telecommunication and ICT industries have started research and innovation for green ICT. Moreover, ICT has the potential to reduce carbon emission of other industries substantially. ICT must be green first. If this green ICT is applied to make other industries green it will lead to a clean and green environment. It is evident that environmental sustainability is prime concern for the development of mankind. With the growing trend of technological advancement there is no alternative to opt for green technology. Green ICT is a prime concern to obtain green technology. Only technological innovation is not sufficient; Global policy framework to deploy universal regulation and benchmark is a crying need. In addition, the end-users must sensitize their adverse impact on environment through use of ICT. On the other hand, Green ICT must be economically viable for practical application. Awareness generation and government stimulus can play a vital role in this regard. So an integrated effort is necessary by the researchers, technologists, environment specialists, International bodies, and governments to meet this global need.
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2. “ZTE Green Technology Innovations White paper”, ZTE Corporations, 2011.
3. “Make It Green-Cloud Computing and its Contribution to Climate Change”, Greenpeace International, March, 2010.
4. http://www.itu.int/en/ITU-T/climatechange/ Pages/standards.aspx